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Sample records for csub 3hsub 3cl

  1. Kinetic isotope effects in the gas phase reactions of OH and Cl with CH3Cl, CD3Cl, and 13CH3Cl

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    S. R. Sellevåg

    2005-06-01

    Full Text Available The kinetic isotope effects in the reactions of CH3Cl, 13CH3Cl and CD3Cl with OH radicals and Cl atoms were studied in relative rate experiments at 298±2K and 1013±10mbar. The reactions were carried out in a smog chamber using long path FTIR detection and the spectroscopic data analyzed employing a non-linear least squares spectral fitting method using measured high-resolution infrared spectra as well as absorption cross sections from the HITRAN database. The reaction rates of 13CH3Cl and CD3Cl with OH and Cl were determined relative to CH3Cl as: kOH + CH3Cl/kOH + 13CH3Cl=1.059±0.008, kOH + CH3Cl/kOH + CD3Cl=3.9±0.4, kCl + CH3Cl/kCl + 13CH3Cl=1.070±0.010 and kCl + CH3Cl/kCl + CD3Cl=4.91±0.07. The uncertainties given are 2σ from the statistical analyses and do not include possible systematic errors. The unusually large 13C kinetic isotope effect in the OH reaction of CH3Cl has important implications for the global emission inventory of CH3Cl.

  2. Kinetic isotope effects in the gas phase reactions of OH and Cl with CH3Cl, CD3Cl, and 13CH3Cl

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    A. A. Gola

    2005-01-01

    Full Text Available The kinetic isotope effects in the reactions of CH3Cl, 13CH3Cl and CD3Cl with OH radicals and Cl atoms were studied in relative rate experiments at 298±2 K and 1013±10 mbar. The reactions were carried out in a smog chamber using long path FTIR detection and the spectroscopic data analyzed employing a non-linear least squares spectral fitting method using measured high-resolution infrared spectra as well as absorption cross sections from the HITRAN database. The reaction rates of 13CH3Cl and CD3Cl with OH and Cl were determined relative to CH3Cl as: kOH+CH3ClkOH+CH3Cl/kOH+13CH3Cl}kOH+13CH3Cl=1.059±0.008, kOH+CH3ClkOH+CH3Cl/kOH+CD3ClkOH+CD3Cl=3.9±0.4, kCl+CH3ClkCl+CH3Cl/kCl+13CH3ClkCl+13CH3Cl =1.070±0.010 and kCl+CH3ClkCl+CH3Cl/kCl+CD3ClkCl+CD3Cl=4.91±0.07. The uncertainties given are 2σ from the statistical analyses and do not include possible systematic errors. The unexpectedly large 13C kinetic isotope effect in the OH reaction of CH3Cl has important implications for the global emission inventory of CH3Cl.

  3. Quantum dynamics of the Walden inversion reaction Cl - +CH3Cl --> ClCH3+Cl -

    Science.gov (United States)

    Clary, David C.; Palma, Juliana

    1997-01-01

    Quantum scattering calculations on the SN2 reaction Cl-+CH3Cl→ClCH3+Cl- are reported. The rotating bond approximation (RBA) has been adapted so that three degrees of freedom including the C-Cl stretching vibration and the CH3 umbrella mode are treated explicitly. The calculations have been done with minor modifications of a potential due to Vande Linde and Hase. It is found that initial excitation of the C-Cl vibration has a large effect on the reaction probabilities, while excitation of the CH3 umbrella vibration is less significant. The reaction is dominated by scattering resonances with lifetimes ranging from 0.1 to 10 ps. It is found that the length of the C-Cl bond at the transition state of the reaction has a particularly pronounced effect on the reaction probabilities. The magnitude of the quantum reaction probabilities compares quite well with those calculated using the quasiclassical trajectory method.

  4. C{sub 60} in photodissociation regions

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    Castellanos, Pablo; Tielens, Alexander G.G.M. [Leiden Observatory, P.O. Box 9513, 2300 RA Leiden (Netherlands); Berné, Olivier [Université de Toulouse, UPS-OMP, IRAP, F-31400 Toulouse (France); Sheffer, Yaron; Wolfire, Mark G., E-mail: pablo@strw.leidenuniv.nl [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)

    2014-10-10

    Recent studies have confirmed the presence of buckminsterfullerene (C{sub 60}) in different interstellar and circumstellar environments. However, several aspects regarding C{sub 60} in space are not yet well understood, such as the formation and excitation processes, and the connection between C{sub 60} and other carbonaceous compounds in the interstellar medium, in particular polycyclic aromatic hydrocarbons (PAHs). In this paper, we study several photodissociation regions (PDRs) where C{sub 60} and PAHs are detected and the local physical conditions are reasonably well constrained to provide observational insights into these questions. C{sub 60} is found to emit in PDRs where the dust is cool (T{sub d} = 20-40 K) and even in PDRs with cool stars. These results exclude the possibility for C{sub 60} to be locked in grains at thermal equilibrium in these environments. We observe that PAH and C{sub 60} emission are spatially uncorrelated and that C{sub 60} is present in PDRs where the physical conditions (in terms of radiation field and hydrogen density) allow for full dehydrogenation of PAHs, with the exception of Ced 201. We also find trends indicative of an increase in C{sub 60} abundance within individual PDRs, but these trends are not universal. These results support models where the dehydrogenation of carbonaceous species is the first step toward C{sub 60} formation. However, this is not the only parameter involved and C{sub 60} formation is likely affected by shocks and PDR age.

  5. Production of C{sub 60} and C{sub 70} fullerenes in benzene-oxygen flames

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    Howard, J.B.; McKinnon, T.; Johnson, M.E. [Massachusetts Institute of Technology, Cambridge, MA (United States)] [and others

    1992-08-06

    Fullernes C{sub 60} and C{sub 70} were produced in varying amounts in premixed laminar benzene/oxygen/argon flames operated under ranges of conditions including pressures of 12-100 Torr and C/O ratios from 0.717 to 1.072, the critical value for soot formation being 0.760. The fullernes were identified in toluene extracts of condensed flame material including soot, using high-performance liquid chromatography (HPLC) with diode-array spectrophotometric detection, mass spectrometry, and infrared spectrophotometry. The yields of C{sub 60} and C{sub 70} and the C{sub 70}/C{sub 60} ratio depend on temperature, pressure, carbon/oxygen ratio, and residence time in the flame. In the sooting flames, C{sub 60} and C{sub 70} first appear well after the onset of soot formation. The mass of C{sub 60} + C{sub 70} produced is in the range 0.0026-902% of the soot, compared to 1-14% of the fuel carbon was found in a nonsooting flame. The largest rate of production of C{sub 60} + C{sub 70} was observed in a sooting flame at a pressure of 100 Torr. The C{sub 70}/C{sub 60} molar ratio varied over the range 0.26-5.7, compared to 0.02-0.18 for the graphite vaporization method, and can be controlled by selection of flame conditions. Depending on flame conditions, the C{sub 60} + C{sub 70} fullernes were produced with varying amounts of polycyclic aromatic hydrocarbons (PAH). The mass ratio of PAH to C{sub 60} + C{sub 70} varies roughly from 0.01 to 100 over the range of conditions studied. Also, the C{sub 60} + C{sub 70} fullerenes are accompanied by metastable C{sub 60} and C{sub 70} isomers as well as C{sub 60}O, C{sub 70}O, C{sub 76}, C{sub 84}, C{sub 90}, and C{sub 94}, the identification of which by liquid chromatography/mass spectrometry is described elsewhere. 49 refs., 5 figs., 2 tabs.

  6. Fractalkine (CX3CL1, a new factor protecting β-cells against TNFα

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    Sabine Rutti

    2014-10-01

    Conclusions: We demonstrate for the first time that human islets express and secrete CX3CL1 and CX3CL1 impacts them by decreasing glucagon secretion without affecting insulin secretion. Moreover, CX3CL1 decreases basal apoptosis of human β-cells. We further demonstrate that CX3CL1 protects β-cells from the adverse effects of TNFα on their function by restoring the expression and phosphorylation of key proteins of the insulin secretion pathway.

  7. CX3CL1 reduces neurotoxicity and microglial activation in a rat model of Parkinson's disease

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    Hudson Charles E

    2011-01-01

    Full Text Available Abstract Background Parkinson's disease is characterized by a progressive loss of dopaminergic neurons in the substantia nigra. The cause of the neurodegeneration is unknown. Neuroinflammation has been clearly shown in Parkinson's disease and may be involved in the progressive nature of the disease. Microglia are capable of producing neuronal damage through the production of bioactive molecules such as cytokines, as well as reactive oxygen species (ROS, and nitric oxide (NO. The inflammatory response in the brain is tightly regulated at multiple levels. One form of immune regulation occurs via neurons. Fractalkine (CX3CL1, produced by neurons, suppresses the activation of microglia. CX3CL1 is constitutively expressed. It is not known if addition of exogenous CX3CL1 beyond otherwise physiologically normal levels could decrease microglia activation and thereby minimize the secondary neurodegeration following a neurotoxic insult. Methods The intrastriatal 6-hydroxydopamine (6-OHDA rat model of Parkinson disease, was used to test the hypothesis that exogenous CX3CL1 could be neuroprotective. Treatment with recombinant CX3CL1 was delivered to the striatum by an osmotic minipump for 28 days beginning 7 days after the initial insult. Unbiased stereological methods were used to quantify the lesion size in the striatum, the amount of neuronal loss in the substantia nigra, and the amount of microglia activation. Results As hypothesized, CX3CL1 was able to suppress this microglia activation. The reduced microglia activation was found to be neuroprotective as the CX3CL1 treated rats had a smaller lesion volume in the striatum and importantly significantly fewer neurons were lost in the CX3CL1 treated rats. Conclusion These findings demonstrated that CX3CL1 plays a neuroprotective role in 6-OHDA-induced dopaminergic lesion and it might be an effective therapeutic target for many neurodegenerative diseases, including Parkinson disease and Alzheimer disease

  8. Synthesis and evaluation of phenylisoserine derivatives for the SARS-CoV 3CL protease inhibitor.

    Science.gov (United States)

    Konno, Hiroyuki; Onuma, Takumi; Nitanai, Ikumi; Wakabayashi, Masaki; Yano, Shigekazu; Teruya, Kenta; Akaji, Kenichi

    2017-06-15

    Synthesis and evaluation of new scaffold phenylisoserine derivatives connected with the essential functional groups against SARS CoV 3CL protease are described. The phenylisoserine backbone was found by simulation on GOLD software and the structure activity relationship study of phenylisoserine derivatives gave SK80 with an IC50 value of 43μM against SARS CoV 3CL R188I mutant protease. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Tl10Hg3Cl16: Single crystal growth, electronic structure and piezoelectric properties

    Science.gov (United States)

    Khyzhun, O. Y.; Piasecki, M.; Kityk, I. V.; Luzhnyi, I.; Fedorchuk, A. O.; Fochuk, P. M.; Levkovets, S. I.; Karpets, M. V.; Parasyuk, O. V.

    2016-10-01

    Single crystal of the ternary halide Tl10Hg3Cl16 was grown using Bridgman-Stockbarger method. For the Tl10Hg3Cl16 crystal, we have measured X-ray photoelectron spectra for both pristine and Ar+ ion-bombarded surfaces and additionally investigated photoinduced piezoelectricity. Our data indicate that the Tl10Hg3Cl16 single crystal surface is very sensitive with respect to Ar+ ion-bombardment. In particular, Ar+ ion-bombardment with energy of 3.0 keV over 5 min at an ion current density of 14 μA/cm2 causes significant changes of the elemental stoichiometry of the Tl10Hg3Cl16 surface resulting in an abrupt decrease of the mercury content in the top surface layers of the studied single crystal. As a result of the treatment, the mercury content becomes nil in the top surface layers. In addition, the present XPS measurements allow for concluding about very low hygroscopicity of the Tl10Hg3Cl16 single crystal surface. The property is extremely important for the crystal handling in optoelectronic or nano-electronic devices working at ambient conditions. The photoinduced piezoelectricity has been explored for Tl10Hg3Cl16 depending on nitrogen (λ=371 nm) laser power density and temperature.

  10. Orientation and photoluminescence of C{sub 60} crystallites in C{sub 60}-polymethyl methacrylate films

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    Ma, G.; Ming, N. [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructures; Cheng, W.; Chen, G. [Department of Physics, Lanzhou University, 730000, Lanzhou (China)

    2000-10-31

    X-ray diffraction measurements indicate that C{sub 60} embedded in polymethyl methacrylate have a high tendency to form crystallites, the size of which increases with C{sub 60} concentrations. Annealing results in the growth of C{sub 60} crystallites and for heavily doped films, rearrangement of them into a predominant (111) orientation. The samples produce intense double-peaked photoluminescence profiles centered at {proportional_to}1.7 and {proportional_to}2.0 eV that vary coordinately upon annealing. The results not only promise an efficient method for preparation of oriented C{sub 60} films on substrates exhibiting strong surface energies such as Si, but also demonstrate the importance of controlling the size distribution of embedded C{sub 60} crystallites for, e.g. obtaining desired photoluminescence. (orig.)

  11. Modulating neurotoxicity through CX3CL1/CX3CR1 signaling

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    Cristina eLimatola

    2014-08-01

    Full Text Available Since the initial cloning of fractalkine/CX3CL1, it was proposed that the only known member of the CX3C or delta subfamily of chemotactic cytokines could play some significant role in the nervous system, due to its high expression on neurons. The pivotal description of the localization of the unique CX3CL1 receptor, CX3CR1, on microglial cells, firmed up by the generation of cx3cr1GFP/GFP mice, opened the road to the hypothesis of some specific key interactions between microglia and neurons mediated by this pair. This expectation has been indeed supported by recent exciting evidence indicating that CX3CL1-mediated microglia-neuron interaction modulates basic physiological activities during development, adulthood and aging, including: synaptic pruning; promoting survival of neurons and neural precursors; modulating synaptic transmission and plasticity; enhancing synapse and network maturation; and facilitating the establishment of neuropathic pain circuits. Beyond playing such fascinating roles in physiological conditions, CX3CL1 signaling has been implicated in different neuropathologies. Early papers demonstrated that the levels of CX3CL1 may be modulated by various toxic stimuli in vitro and that CX3CL1 signaling is positively or negatively regulated in EAE and MS, in HIV infection and LPS challenge, in epilepsy, in brain tumors, and in other neuropathologies. In this review we focus on the experimental evidence of CX3CL1 involvement in neuroprotection and survey the common molecular and cellular mechanisms described in different brain diseases.

  12. Seasonality of water availability and the effects of climate change on the distribution of C{sub 3} and C{sub 4} grasses in the Great Plains

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    Lauenroth, W.K.; Coffin, D.P.; Sala, O.E. [Colorado State Univ., Ft. Collins, CO (United States)]|[Univ. of Buenos Aires (Argentina)

    1995-09-01

    We used a daily time step simulation model to evaluate the role of temperature and soil water in explaining the relative importance of C{sub 3} and C{sub 4} grasses and to evaluate potential effect of climate change (IPCC {open_quotes}Business-as Usual{close_quotes} scenario) at two sites; one dominated by C{sub 4} grasses (CPER) and the other dominated by a mixture of C{sub 3} and C{sub 4} grasses (CHEY). Under current conditions, both the lengths and the integrated performance of plants during the C{sub 3} growing seasons exceeded the C{sub 4} growing seasons at each site. The activity of C{sub 3} plants at the CPER represented 64% of the total (C3+C4) growing-slightly more favorable for C{sub 3} grasses and substantially more favorable for C{sub 4} grasses. The predicted decrease in precipitation resulted in a larger decrease for C{sub 3} than for C{sub 4} grasses at both sites. Changing both precipitation and temperature produced results very similar to the temperature treatment. Our conclusions are that current scenarios for climate change in the central Great Plains will very likely favor C{sub 4} grasses to the detriment of C{sub 3}s.

  13. Molecular cloning, expression, purification and crystallographic analysis of PRRSV 3CL protease

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    Tian, Xinsheng; Feng, Youjun [Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); Graduate University, Chinese Academy of Sciences, Beijing 100049 (China); Zhao, Tiezhu [China Animal Disease Control Center, Beijing 100094 (China); Peng, Hao; Yan, Jinghua [Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); Qi, Jianxun [Graduate University, Chinese Academy of Sciences, Beijing 100049 (China); Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Jiang, Fan [Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Tian, Kegong, E-mail: tiankg@263.net [China Animal Disease Control Center, Beijing 100094 (China); Gao, Feng, E-mail: tiankg@263.net [Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); College of Biological Sciences, China Agricultural University, Beijing 100094 (China)

    2007-08-01

    Recombinant PRRSV 3CL protease was crystallized and the crystals diffracted to 2.1 Å resolution. 3CL protease, a viral chymotrypsin-like proteolytic enzyme, plays a pivotal role in the transcription and replication machinery of many RNA viruses, including porcine reproductive and respiratory syndrome virus (PRRSV). In this study, the full-length 3CL protease from PRRSV was cloned and overexpressed in Escherichia coli. Crystallization experiments yielded crystals that diffracted to 2.1 Å resolution and belong to space group C2, with unit-cell parameters a = 112.31, b = 48.34, c = 42.88 Å, β = 109.83°. The Matthews coefficient and the solvent content were calculated to be 2.49 Å{sup 3} Da{sup −1} and 50.61%, respectively, for one molecule in the asymmetric unit.

  14. Photofragmentation of CF{sub 3}Cl following photoabsorption in the Cl-ls threshold region

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    Lindle, D.W.; Manner, W.L.; Steinbeck, L. [and others

    1993-05-01

    Measurements of photofragmentation of CF{sub 3}Cl near the Cl-ls threshold (hv=2.8 keV) are reported. Because of the dominant decay mode of a Cl-ls hole state, Auger-electron emission, usually occurs sequentially in a vacancy cascade, high degrees of ionization of the parent molecule are induced. As a result, the observed photofragment-ion spectra of CF{sub 3}Cl contain primarily singly and multiply charged atomic fragments. Based on modelling of the spectral peak shapes, these fragments have a wide range of kinetic energies due to the dissociation process. Changes in peak shapes are observed following resonant excitation, as oppossed to ionization, of the Cl-ls electron, and may be due to either sequential fragmentation of CF{sub 3}Cl{sup n+} or to angular-distribution effects due to alignment of the initially excited resonant state.

  15. Calorimetric measurements on Li{sub 4}C{sub 60} and Na{sub 4}C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, Akira; Miyazaki, Yuji [Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Michałowski, Paweł P.; Gracia-Espino, Eduardo; Wågberg, Thomas, E-mail: Thomas.wagberg@physics.umu.se [Department of Physics, Umeå University, S-90187 Umeå (Sweden); Sundqvist, Bertil [Department of Physics, Umeå University, S-90187 Umeå (Sweden); State Key Laboratory for Superhard Materials, Jilin University, Changchun 130012 (China)

    2015-04-28

    We show specific heat data for Na{sub 4}C{sub 60} and Li{sub 4}C{sub 60} in the range 0.4-350 K for samples characterized by Raman spectroscopy and X-ray diffraction. At high temperatures, the two different polymer structures have very similar specific heats both in absolute values and in general trend. The specific heat data are compared with data for undoped polymeric and pristine C{sub 60}. At high temperatures, a difference in specific heat between the intercalated and undoped C{sub 60} polymers of 100 J K{sup −1} mol{sup −1} is observed, in agreement with the Dulong-Petit law. At low temperatures, the specific heat data for Li{sub 4}C{sub 60} and Na{sub 4}C{sub 60} are modified by the stiffening of vibrational and librational molecular motion induced by the polymer bonds. The covalent twin bonds in Li{sub 4}C{sub 60} affect these motions to a somewhat higher degree than the single intermolecular bonds in Na{sub 4}C{sub 60}. Below 1 K, the specific heats of both materials become linear in temperature, as expected from the effective dimensionality of the structure. The contribution to the total specific heat from the inserted metal ions can be well described by Einstein functions with T{sub E} = 386 K for Li{sub 4}C{sub 60} and T{sub E} = 120 K for Na{sub 4}C{sub 60}, but for both materials we also observe a Schottky-type contribution corresponding to a first approximation to a two-level system with ΔE = 9.3 meV for Li{sub 4}C{sub 60} and 3.1 meV for Na{sub 4}C{sub 60}, probably associated with jumps between closely spaced energy levels inside “octahedral-type” ionic sites. Static magnetic fields up to 9 T had very small effects on the specific heat below 10 K.

  16. Superconductivity in alkali-doped C{sub 60}

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    Ramirez, Arthur P., E-mail: apr@ucsc.edu

    2015-07-15

    Highlight: • Superconductivity in alkali-doped C{sub 60} (A{sub 3}C{sub 60}) is well described by an s-wave state produced by phonon mediated pairing. • Moderate coupling of electrons to high-frequency shape-changing intra-molecular vibrational modes produces transition temperatures up to 33 K in single-phase material. • The good understanding of pairing in A{sub 3}C{sub 60} offers a paradigm for the development of new superconducting materials. - Abstract: Superconductivity in alkali-doped C{sub 60} (A{sub 3}C{sub 60}, A = an alkali atom) is well described by an s-wave state produced by phonon mediated pairing. Moderate coupling of electrons to high-frequency shape-changing intra-molecular vibrational modes produces transition temperatures (T{sub c}) up to 33 K in single-phase material. The good understanding of pairing in A{sub 3}C{sub 60} offers a paradigm for the development of new superconducting materials.

  17. Reflection electron energy-loss spectra of the fullerenes C[sub 60] and C[sub 70

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    Shul' ga, Yu.M. (Institute of Chemical Physics, Chernogolovka (Russian Federation)); Rubtsov, V.I. (Institute of Chemical Physics, Chernogolovka (Russian Federation)); Lobach, A.S. (Institute of Chemical Physics, Chernogolovka (Russian Federation))

    1994-02-01

    High purity polycrystalline samples of C[sub 60] and C[sub 70] were obtained and studied by the electron energy-loss spectroscopy in the reflection mode. The spectra were used for determination of the loss functions of fullerenes. Loss functions of the fullerenes were compared with those of graphite. It was established that the relative intensities of the peaks corresponding to ([sigma]+[pi])- and [pi]-plasmons depended on the primary electron energy, while the ([sigma]+[pi])-plasmon energies did not depend on the primary electron energy and were equal to 25.0 eV for C[sub 60] and 24.8 eV for C[sub 70]. The conclusion on the space localization for plasma occilations in fullerenes was made on the base of the study of the energy dependent loss functions. (orig.)

  18. Session 6: Highly active Pt/zeolite catalysts for combustion of C{sub 2}-C{sub 4} alkanes

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    Garetto, T.F.; Rincon, E.; Apesteguia, C.R. [Instituto de Investigaciones en Catalisis y Petroquimica -INCAPE- (UNL-CONICET), Santa Fe (Argentina)

    2004-07-01

    In an attempt for developing more active Pt-based catalysts for lower-alkane combustion, we investigate in this work the deep oxidation of C{sub 2}-C{sub 4} alkanes over Pt-based catalysts. Results show that the lower alkane oxidation turnover rates are more than two orders of magnitude higher on Pt/zeolites compared to Pt/Al{sub 2}O{sub 3} catalyst. (authors)

  19. Fused-ring structure of decahydroisoquinolin as a novel scaffold for SARS 3CL protease inhibitors.

    Science.gov (United States)

    Shimamoto, Yasuhiro; Hattori, Yasunao; Kobayashi, Kazuya; Teruya, Kenta; Sanjoh, Akira; Nakagawa, Atsushi; Yamashita, Eiki; Akaji, Kenichi

    2015-02-15

    The design and evaluation of a novel decahydroisoquinolin scaffold as an inhibitor for severe acute respiratory syndrome (SARS) chymotrypsin-like protease (3CL(pro)) are described. Focusing on hydrophobic interactions at the S2 site, the decahydroisoquinolin scaffold was designed by connecting the P2 site cyclohexyl group of the substrate-based inhibitor to the main-chain at the α-nitrogen atom of the P2 position via a methylene linker. Starting from a cyclohexene enantiomer obtained by salt resolution, trans-decahydroisoquinolin derivatives were synthesized. All decahydroisoquinolin inhibitors synthesized showed moderate but clear inhibitory activities for SARS 3CL(pro), which confirmed the fused ring structure of the decahydroisoquinolin functions as a novel scaffold for SARS 3CL(pro) inhibitor. X-ray crystallographic analyses of the SARS 3CL(pro) in a complex with the decahydroisoquinolin inhibitor revealed the expected interactions at the S1 and S2 sites, as well as additional interactions at the N-substituent of the inhibitor. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Modulation of the work function of fullerenes C{sub 60} and C{sub 70} by alkali-metal adsorption: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Hong [Institute of Architecture and Engineering, Weifang University of Science and Technology, Weifang 262700 (China); Xu, Shunfu, E-mail: xushunfu2009@gmail.com [Institute of Architecture and Engineering, Weifang University of Science and Technology, Weifang 262700 (China); Department of Physics, Institute of Information Science and Engineering, Ocean University of China, Qingdao 266100 (China); Liu, Weihui [Department of Physics, Institute of Information Science and Engineering, Ocean University of China, Qingdao 266100 (China); Sun, Yueqiang; Liu, Xiangfa; Zheng, Xinqing; Li, Sen; Zhang, Qiang; Zhu, Ziliang; Zhang, Xiaochun; Dong, Chengguo [Institute of Architecture and Engineering, Weifang University of Science and Technology, Weifang 262700 (China); Li, Chun [Department of Physics, Institute of Information Science and Engineering, Ocean University of China, Qingdao 266100 (China); Yuan, Guang, E-mail: yuanguang@ouc.edu.cn [Department of Physics, Institute of Information Science and Engineering, Ocean University of China, Qingdao 266100 (China); Research Institute of Electronics, University of Shizuoka, Hamamasu 432-8011 (Japan); Mimura, Hitenori [Department of Physics, Institute of Information Science and Engineering, Ocean University of China, Qingdao 266100 (China)

    2013-11-15

    The impact of alkali-metal (Li/Na/Cs) adsorption on work function of fullerenes C{sub 60} and C{sub 70} was investigated by first-principles calculations. After adsorption, the work functions of fullerenes C{sub 60} and C{sub 70} decrease distinctly and vary linearly with the electronegativity of the alkali metal elements, and the positions where the alkali atoms are adsorbed considerably influence the work functions. On the contrary, a vacancy defect elevates the work functions of the fullerenes C{sub 60} and C{sub 70}. The variation in the work functions rests with variation in Fermi level (which are attributed to charge transfer) and variation in vacuum levels (which are attributed to the induced dipole moments). Moreover, alkali-metal adsorption can also improve the electric conductivity of a fullerene mixture of C{sub 60} and C{sub 70}.

  1. Disordered and ordered C{sub {bold 28}} solids

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    Kim, J. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Galli, G. [Institut Romand de Recherche Numerique en Physique des Materiaux (IRRMA), Ecublens, 1015 Lausanne (Switzerland); Wilkins, J.W. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Canning, A. [CRAY Research, PSE, EPFL, 1015Lausanne (Switzerland)

    1998-02-01

    Using tight-binding molecular dynamics, we have performed computer experiments to mimic the gas phase growth of a disordered solid composed of C{sub 28} fullerenes. The growth has been simulated by repeated low energy collisions of molecules coming from random directions. The resulting solid is composed of undamaged C{sub 28} cages, with most fullerenes being three- and four-fold coordinated, similar to C atoms in amorphous materials. The system contains a high percentage of distorted sp{sup 2} C sites and only a small proportion of sp{sup 3} sites. These results help clarify the structure of disordered films obtained experimentally by small fullerene deposition on surfaces. Furthermore, we have compared the properties of the disordered C{sub 28} solid (a-C{sub 28}) with those of ordered C{sub 28} solids. We have found that the energy of a-C{sub 28} is close to that of hyperdiamond (0.1 eV/atom higher) and differs by a few meV from that of other ordered structures, such as 2D-hypergraphite, hexagonal and clathrate solids. This indicates that in condensed phases C{sub 28} molecules can act as carbon superatoms, while showing more bonding flexibility than C atoms; in particular the capability of acting as six-fold coordinated building blocks of hexagonal solids, which are as stable as a-C{sub 28}. {copyright} {ital 1998 American Institute of Physics.}

  2. Mechanisms and Kinetics of Reactions of the O (1D,3p) + CF3Cl System

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ In the stratosphere, CF3Cl (CFC 13) can either photodecompose or react directly with atomic oxygen to generate ozone-depleting agents such as Cl and ClO in the gas phase[1-3]. Since the 1970s, attention has been focused on the effects of these compounds on the destruction of ozone in the stratosphere and on global warming[4,5].

  3. Fractalkine/CX3CL1 engages different neuroprotective responses upon selective glutamate receptor overactivation.

    Directory of Open Access Journals (Sweden)

    Clotilde eLauro

    2015-01-01

    Full Text Available Neuronal death induced by overactivation of N-methyl-d-aspartate receptors (NMDARs is implicated in the pathophysiology of many neurodegenerative diseases such as stroke, epilepsy and traumatic brain injury. This toxic effect is mainly mediated by NR2B-containing extrasynaptic NMDARs, while NR2A-containing synaptic NMDARs contribute to cell survival, suggesting the possibility of therapeutic approaches targeting specific receptor subunits. We report that fractalkine/CX3CL1 protects hippocampal neurons from NMDA-induced cell death with a mechanism requiring the adenosine receptors type 2A (A2AR. This is different from CX3CL1-induced protection from glutamate-induced cell death, that fully depends on A1R and requires in part A3R. We show that CX3CL1 neuroprotection against NMDA excitotoxicity involves D-serine, a co-agonist of NR2A/NMDAR, resulting in cyclic AMP-dependent transcription factor (CREB phosphorylation.

  4. Critical role of fractalkine (CX3CL1) in cigarette smoke-induced mononuclear cell adhesion to the arterial endothelium.

    Science.gov (United States)

    Rius, Cristina; Company, Chantal; Piqueras, Laura; Cerdá-Nicolás, Jose Miguel; González, Cruz; Servera, Emilio; Ludwig, Andreas; Morcillo, Esteban J; Sanz, Maria-Jesus

    2013-02-01

    Cigarette smoking is an important risk factor for the development of cardiovascular disease, yet the pathways through which this may operate are poorly understood. Therefore, the mechanism underlying cigarette smoke (CS)-induced arterial endothelial dysfunction and the potential link with fractalkine/CX(3)CL1 upregulation were investigated. Stimulation of human arterial umbilical endothelial cells (HUAECs) with pathophysiological concentrations of CS extract (1% CSE) increased CX(3)CL1 expression. Neutralisation of CX(3)CL1 activity under dynamic flow conditions significantly inhibited CSE-induced mononuclear cell adhesion to HUAECs (67%). The use of small interfering RNA (siRNA) revealed that nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 5 (Nox5) but not Nox2 or Nox4 is the main NADPH isoform involved in CSE-induced CX(3)CL1 upregulation and mononuclear cell arrest. Knock down of HUAEC tumour necrosis factor α expression with siRNA or pharmacological inhibition of p38 mitogen-activated protein kinase and nuclear factor κB also abolished these responses. Interestingly, circulating monocytes and lymphocytes from patients with chronic obstructive pulmonary disease (COPD) (n=29) versus age-matched controls (n=23) showed CX(3)CR1overexpression. Furthermore, CX(3)CL1 neutralisation dramatically diminished their enhanced adhesiveness to CSE-stimulated HUAECs. Finally, when animals were exposed for 3 days to CS, a mild inflammatory response in the lung was observed which was accompanied by enhanced CX(3)CL1 expression in the cremasteric arterioles, an organ distant from the lung. CS exposure resulted in increased leukocyte-arteriolar endothelial cell adhesion which was significantly reduced (51%) in animals lacking CX(3)CL1 receptor (CX(3)CR1). These results suggest that CS induces functional CX(3)CL1 expression in arterial endothelium and leukocytes from patients with COPD show increased CX(3)CL1-dependent adhesiveness. Therefore, targeting the CX(3)CL1

  5. Pulse-radiolysis study of cytochrome c/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    van Leeuwen, W.; van Dijk, C.; Grande, H.J.; Veeger, C.

    1982-10-02

    Pulse-radiolysis experiments were performed in the presence of methyl viologen and cytochrome c/sub 3/. After the pulse, methyl viologen radicals are formed and the kinetics of these radicals with cytochrome c/sub 3/ are studied. The reaction between cytochrome c/sub 3/ and methyl viologen radicals (MV/sup +/) is diffusion controlled. The ionic strength dependence and the pH-dependence of this reaction were studied. From the ionic strength dependence (at pH 7.8) we found that the net charge of the fully oxidized cytochrome c/sub 3/ molecule was Z = +4.7 +- 0.7. After the pulse an equilibrium is reached for the reaction of MV/sup +/ with cytochrome c/sub 3/. From this equilibrium an apparent midpoint potential can be obtained. The apparent midpoint potential of this multihaem molecule was found to depend on the degree of reduction, ..cap alpha... With the help of the Nernst equation an empirical equation is obtained to describe this dependence of the midpoint potential: E/sub 0/ = -0.250-0.088 x (in V). An estimation is made of the energy of interaction between the haems due to electrostatic interactions (..delta..epsilon < 32 mV) and due to ionic strength effects (-12 mV < ..delta..epsilon < 26 mV). The results suggest that the redox properties of the individual haems in the cytochrome c/sub 3/ molecule are dependent on the degree of reduction of the other haems in the molecule. The reaction of cytochrome c/sub 3/ with MV/sup +/ or with ethanol radicals (EtOHsup(.)) has been compared with the reactions of horse-heart cytochrome c and of metmyoglobin with the same radicals. The reaction of MV/sup +/ or EtOHsup(.) with horse-heart cytochrome c is found to be diffusion controlled; the reactions with metmyoglobin on the other hand are most probably controlled by an activation energy.

  6. Me4NO2CSO3H.2SnPh3Cl AND enH2O2CSO3.SnPh3Cl SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    DAOUDA NDOYE

    2013-12-01

    Full Text Available Me4NO2C-SO3H.2SnPh3Cl and enH2O2C-SO3.SnPh3Cl are obtained on allowing Me4NO2C-SO3H and enH2O2C-SO3 to react with SnPh3Cl in respectively mixed solution (ethanol/water or ethanolic solution in specific ratios. Their infrared studies have been carried out and structures as dimers, suggested when hydrogen bonds are involved.

  7. Complexes of ruthenium(II) with bpmRe(CO) sub 3 Cl and HAT(Re(CO) sub 3 Cl) sub 2 as ligands: Syntheses and redox and luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, R.; Rillema, D.P.; Shaver, R.; Van Wallendael, S.; Jackman, D.C.; Boldaji, M. (Univ. of North Carolina, Charlotte (USA))

    1989-03-22

    A series of mixed-metal complexes containing ruthenium and rhenium are reported. The new complexes are ((bpy)Ru-(bpmRe(CO){sub 3}Cl){sub 2})(PF{sub 6}){sub 2}, ((bpy){sub 2}RuHAT(Re(CO){sub 3}Cl){sub 2})(PF{sub 6}){sub 2}, and (Ru(bpmRe(CO){sub 3}Cl){sub 3})(PF{sub 6}){sub 2}. Optical transitions in the visible-uv spectrum are dominated by the presence of the ruthenium heterocycles that have absorption coefficients for the low-energy transition 1 order of magnitude greater than that of the rhenium chromophore. The low-energy transition blue-shifts in the series ((bpy){sub 2}Ru(bpmRe(CO){sub 3}Cl)){sup 2+} (558 nm) < ((bpy)Ru(bpmRe(CO){sub 3}Cl){sub 2}){sup 2+} (531 nm) < (Ru(bpmRe(CO){sub 3}Cl){sub 3}){sup 2+} (501 nm). Polarographic half-wave potentials of the metal-centered oxidations and the bridging-ligand reductions shift positively as the number of Re(CO){sub 3}Cl units increase. The E{sub {1/2}} values for the ((bpy){sub n}Ru(bpmRe(CO){sub 3}Cl){sub 3-n}){sup 2+/+} couple in the series with n = 0-2 were -0.1, -0.33, and -0.41 V vs SSCE, respectively. Two complexes ((bpy)Ru(bpmRe(CO){sub 3}Cl){sub 2}){sup 2+} and ((Ru-(bpmRe(CO){sub 3}Cl){sub 3})){sup 2+}, were found to luminesce weakly at room temperature in acetonitrile with lifetimes of 942 and 847 ns, respectively. In many respects, the mixed-metal complexes are shown to behave as if the bpmRe(CO){sub 3}Cl and HAT(Re(CO){sub 3}Cl){sub 2} chromophores are ligands coordinated to ruthenium(II). 17 refs., 8 figs., 4 tabs.

  8. Gabapentin reduces CX3CL1 signaling and blocks spinal microglial activation in monoarthritic rats

    Directory of Open Access Journals (Sweden)

    Yang Jia-Le

    2012-05-01

    Full Text Available Abstract Background Spinal glia, particularly microglia and astrocytes, are of the utmost importance in the development and maintenance of chronic pain. A recent study from our laboratory revealed that gabapentin, a recommended first-line treatment for multiple neuropathic conditions, could also efficiently antagonize thermal hyperalgesia evoked by complete Freund's adjuvant (CFA-induced monoarthritis (MA. In the present study, we investigated whether the spinal glia are involved in the anti-hyperalgesic effect of gabapentin and how this event occurs. Results Unilateral intra-articular injection of CFA produced a robust activation of microglia and astrocytes. These cells exhibited large cell bodies, thick processes and increases in the ionized calcium binding adapter molecule 1 (Iba-1, a microglial marker or the glia fibrillary acidic protein (GFAP, an astrocytic marker. These cells also displayed immunoreactive signals, and an upregulation of the voltage-gated calcium channels (VGCCs α2/δ-1 subunit, CX3CL1 and CX3CR1 expression levels in the spinal cord. These changes were associated with the development of thermal hyperalgesia. Immunofluorescence staining showed that VGCC α2/δ-1 subunit, a proposed gabapentin target of action, was widely distributed in primary afferent fibers terminals and dorsal horn neurons. CX3CL1, a potential trigger to activate microglia, colocalized with VGCC α2/δ-1 subunits in the spinal dorsal horn. However, its receptor CX3CR1 was mainly expressed in the spinal microglia. Multiple intraperitoneal (i.p. gabapentin injections (100 mg/kg, once daily for 4 days with the first injection 60 min before intra-articular CFA suppressed the activation of spinal microglia, downregulated spinal VGCC α2/δ-1 subunits decreased CX3CL1 levels and blocked the development of thermal hyperalgesia in MA rats. Conclusions Here we provide the first evidence that gabapentin diminishes CX3CL1 signaling and spinal microglia

  9. Low-energy elastic electron scattering from chloromethane, CH3Cl

    Science.gov (United States)

    Navarro, C.; Sakaamini, A.; Cross, J.; Hargreaves, L. R.; Khakoo, M. A.; Fedus, Kamil; Winstead, C.; McKoy, V.

    2015-10-01

    We report theoretical as well as (normalized) experimental differential and integral cross sections for vibrationally elastic scattering of low-energy electrons from chloromethane, CH3Cl, also known as methyl chloride. The theoretical cross sections were computed using the Schwinger multichannel variational method in the single-channel approximation, with polarization effects included via virtual excitations. Cross section measurements were made at incident energies ranging from 0.5 to 100 eV and at scattering angles from {5}\\circ to {125}\\circ . We compare our data to earlier previous results for this molecule.

  10. Cytochrome c{sub 6B} of Synechococcus sp. WH 8102 – Crystal structure and basic properties of novel c{sub 6}-like family representative

    Energy Technology Data Exchange (ETDEWEB)

    Zatwarnicki, Pawel [Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot Curie 14a, 50-383 Wroclaw (Poland); Barciszewski, Jakub [Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan (Poland); Krzywda, Szymon [Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan (Poland); Jaskolski, Mariusz [Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan (Poland); Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan (Poland); Kolesinski, Piotr [Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot Curie 14a, 50-383 Wroclaw (Poland); Szczepaniak, Andrzej, E-mail: Andrzej.Szczepaniak@ibmb.uni.wroc.pl [Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot Curie 14a, 50-383 Wroclaw (Poland)

    2014-01-24

    Highlights: • Crystal structure of cytochrome c{sub 6B} from Synechococcus sp. WH 8102 was solved. • Basic biophysical properties of cytochrome c{sub 6B} were determined. • Cytochrome c{sub 6B} exhibits similar architecture to cytochrome c{sub 6}. • Organization of heme binding pocket of cytochrome c{sub 6B} differs from that of c{sub 6}. • Midpoint potential of cytochrome c{sub 6B} is significantly lower than of cytochrome c{sub 6}. - Abstract: Cytochromes c are soluble electron carriers of relatively low molecular weight, containing single heme moiety. In cyanobacteria cytochrome c{sub 6} participates in electron transfer from cytochrome b{sub 6}f complex to photosystem I. Recent phylogenetic analysis revealed the existence of a few families of proteins homologous to the previously mentioned. Cytochrome c{sub 6A} from Arabidopsis thaliana was identified as a protein responsible for disulfide bond formation in response to intracellular redox state changes and c{sub 550} is well known element of photosystem II. However, function of cytochromes marked as c{sub 6B}, c{sub 6C} and c{sub M} as well as the physiological process in which they take a part still remain unidentified. Here we present the first structural and biophysical analysis of cytochrome from the c{sub 6B} family from mesophilic cyanobacteria Synechococcus sp. WH 8102. Purified protein was crystallized and its structure was refined at 1.4 Å resolution. Overall architecture of this polypeptide resembles typical I-class cytochromes c. The main features, that distinguish described protein from cytochrome c{sub 6}, are slightly red-shifted α band of UV–Vis spectrum as well as relatively low midpoint potential (113.2 ± 2.2 mV). Although, physiological function of cytochrome c{sub 6B} has yet to be determined its properties probably exclude the participation of this protein in electron trafficking between b{sub 6}f complex and photosystem I.

  11. Arterial and venous endothelia display differential functional fractalkine (CX3CL1) expression by angiotensin-II.

    Science.gov (United States)

    Rius, Cristina; Piqueras, Laura; González-Navarro, Herminia; Albertos, Fernando; Company, Chantal; López-Ginés, Concha; Ludwig, Andreas; Blanes, Jose-Ignacio; Morcillo, Esteban J; Sanz, Maria-Jesus

    2013-01-01

    Angiotensin-II (Ang-II) promotes the interaction of mononuclear cells with arterioles and neutrophils with postcapillary venules. To investigate the mechanisms underlying this dissimilar response, the involvement of fractalkine (CX(3)CL1) was explored. Enhanced CX(3)CL1 expression was detected in both cremasteric arterioles and postcapillary venules 24 hours after Ang-II intrascrotal injection. Arteriolar leukocyte adhesion was the unique parameter significantly reduced (83%) in animals lacking CX(3)CL1 receptor (CX(3)CR1). Human umbilical arterial and venous endothelial cell stimulation with 1 μmol/L Ang-II increased CX(3)CL1 expression, yet neutralization of CX(3)CL1 activity only significantly inhibited Ang-II-induced mononuclear cell-human umbilical arterial endothelial cell interactions (73%) but not with human umbilical venous endothelial cells. The use of small interfering RNA revealed the involvement of tumor necrosis factor-α in Ang-II-induced CX(3)CL1 upregulation and mononuclear cell arrest. Nox5 knockdown with small interfering RNA or pharmacological inhibition of extracellular signal-regulated kinases1/2, p38 mitogen-activated protein kinase, and nuclear factor-κB also abolished these responses. Finally, when human umbilical arterial endothelial cells were costimulated with Ang-II, tumor necrosis factor-α, and interferon-γ, CX(3)CL1 expression and mononuclear cell adhesiveness were more pronounced than when each stimulus was provided alone. These results suggest that Ang-II induces functional CX(3)CL1 expression in arterial but not in venous endothelia. Thus, targeting endothelial CX(3)CL1-mononuclear leukocyte CX(3)CR1 interactions may constitute a new therapeutic strategy in the treatment of Ang-II-associated cardiovascular diseases.

  12. Selective synthesis of clinoatacamite Cu2(OH)3Cl and tenorite CuO nanoparticles by pH control

    DEFF Research Database (Denmark)

    Engelbrekt, Christian; Malcho, Phillip; Andersen, Jonas

    2014-01-01

    , it directed the growth of Cu2(OH)3Cl to provide pure clinoatacamite without the presence of related poly- morphs. The products were characterized by transmission electron microscopy, infrared spectroscopy, ultraviolet–visible light spectroscopy, X-ray powder diffraction (XRD), scanning transmission X......-ray microscopy and atomic force microscopy. Infrared spectroscopy was essential for characterization of closely related polymorphs of Cu2(OH)3Cl indistinguishable by XRD. A plausible mechanism has been proposed and discussed for the formation of the CuO and Cu2(OH)3Cl nanostructures....

  13. Dissociation of deep-core-excited CH{sub 3}Cl

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, D.L.; Martin, R.; Vanderford, B. [Univ. of Nevada, Las Vegas, NV (United States)] [and others

    1997-04-01

    Using x-rays from B.L. 9.3.1, a space-focused time-of-flight (TOF) was used to study photofragmentation of CH{sub 3}Cl following excitation in the neighborhood of the Cl K-shell threshold ({approximately} 2.8 keV). Multi-ion coincidence measurements were used to search for selective dissociation of specific bonds in the molecule. Such selectivity has been observed for excitation near outer-core-level thresholds (e.g., Cl 2p), but this is the first study in deep core levels, where very-short core-hole lifetimes and Auger cascade effects may influence fragmentation. Both high-resolution time-of-flight spectroscopy and multi-coincidence photoelectron-photoion-photoion (PE-PIPICO), as well as photoelectron-photoion-photoion-photoion (PE3PICO) measurements were performed. Dramatic changes in the line shapes for different fragment ions are observed as a function of the excitation energy, and are attributed to selective dissociation of the CH{sub 3}Cl molecule along the C-Cl bond. In addition, pronounced angular distributions of the ejected ions are observed on resonance.

  14. Low-frequency excitations in Rb{sub 3}C{sub 60} and Rb{sub 6}C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Schober, H. [Institut Max von Laue - Paul Langevin, 38 - Grenoble (France); Renker, B. [INFP, Forschungszentrum Karlsruhe, D-76021 Karlsruhe (Germany); Gompf, F. [INFP, Forschungszentrum Karlsruhe, D-76021 Karlsruhe (Germany)

    1996-04-01

    We present inelastic neutron scattering results for Rb{sub 3}C{sub 60} and Rb{sub 6}C{sub 60} covering the energy region from 0.5 to 14 meV. The different contributions to the spectra (translational, libronic, Rb-vibrations) are discussed on the basis of their Q and temperature dependence. In superconducting Rb{sub 3}C{sub 60} the scattering intensity observed in the range from 1.5 to 3.5 meV changes anomalously with temperature. No such behaviour is found in insulating Rb{sub 6}C{sub 60}. (orig.).

  15. Is C[sub 60] fullerite harder than diamond

    Energy Technology Data Exchange (ETDEWEB)

    Blank, V. (Institute of High Pressure Physics of the Russian Academy of Sciences, 142092 Troitsk, Moscow Region (Russian Federation)); Popov, M. (Institute of High Pressure Physics of the Russian Academy of Sciences, 142092 Troitsk, Moscow Region (Russian Federation)); Buga, S. (Institute of High Pressure Physics of the Russian Academy of Sciences, 142092 Troitsk, Moscow Region (Russian Federation)); Davydov, V. (Institute of High Pressure Physics of the Russian Academy of Sciences, 142092 Troitsk, Moscow Region (Russian Federation)); Denisov, V.N. (Institute of Spectroscopy of the Russian Academy of Sciences, 142092 Troitsk, Moscow Region (Russian Federation)); Ivlev, A.N. (Institute of Spectroscopy of the Russian Academy of Sciences, 142092 Troitsk, Moscow Region (Russian Federation)); Mavrin, B.N. (Institute of Spectroscopy of the Russian Academy of Sciences, 142092 Troitsk, Moscow Region (Russian Federation)); Agafonov, V. (Laboratoire de Chimie Physique, Faculte de Pharmaci

    1994-05-23

    Raman spectra of C[sub 60] fullerite at pressures up to 37 GPa with shear deformation are studied. We have found two states at high pressures, that persist after pressure release and have various transparencies in the near IR region. The nontransparent state is formed at 6-18 GPa and has a Raman spectrum with broadened bands at frequencies close to those of the initial fullerite. The transparent state was obtained at pressures higher than 18 GPa, and the Raman bands are broadened and overlapping in comparison with those of the nontransparent state. We suppose that C[sub 60] molecules persist in both states. The transparent state of fullerite shows a hardness higher than that of diamond. ((orig.))

  16. CX3CL1(+ Microparticles Mediate the Chemoattraction of Alveolar Macrophages toward Apoptotic Acute Promyelocytic Leukemic Cells

    Directory of Open Access Journals (Sweden)

    Wen-Hui Tsai

    2014-02-01

    Full Text Available Background/Aims: During the resolution phase of inflammation, release of “find-me” signals by apoptotic cells is crucial in the chemoattraction of macrophages toward apoptotic cells for subsequent phagocytosis, in which microparticles derived from apoptotic cells (apo-MPs are involved. A recent study reports that CX3CL1 is released from apoptotic cells to stimulate macrophages chemotaxis. In this study, we investigated the role of CX3CL1 in the apo-MPs in the cell-cell interaction between alveolar macrophage NR8383 cells and apoptotic all-trans retinoic acid-treated NB4 (ATRA-NB4 cells. Methods/Results: Apoptotic ATRA-NB4 cells and their conditioning medium (CM enhanced the chemoattraction of NR8383 cells as well as their phagocytosis activity in engulfing apoptotic ATRA-NB4 cells. The levels of CX3CL1(+ apo-MPs and CX3CL1 were rapidly elevated in the CM of ATRA-NB4 cell culture after induction of apoptosis. Both exogenous CX3CL1 and apo-MPs enhanced the transmigration of NR8383 cells toward apoptotic ATRA-NB4 cells. This pro-transmigratory activity was able to be partially inhibited either by blocking the CX3CR1 (CX3CL1 receptor of NR8383 cells with its specific antibody or by blocking the surface CX3CL1 of apo-MPs with its specific antibody before incubating these apo-MPs with NR8383 cells. Conclusion: CX3CL1(+ apo-MPs released by apoptotic cells mediate the chemotactic transmigration of alveolar macrophages.

  17. CX3CL1 is up-regulated in the rat hippocampus during memory-associated synaptic plasticity

    Directory of Open Access Journals (Sweden)

    Graham K Sheridan

    2014-08-01

    Full Text Available Several cytokines and chemokines are now known to play normal physiological roles in the brain where they act as key regulators of communication between neurons, glia and microglia. In particular, cytokines and chemokines can affect cardinal cellular and molecular processes of hippocampal-dependent long-term memory consolidation including synaptic plasticity, synaptic scaling and neurogenesis. The chemokine, CX3CL1 (fractalkine, has been shown to modulate synaptic transmission and long-term potentiation (LTP in the CA1 pyramidal cell layer of the hippocampus. Here, we confirm widespread expression of CX3CL1 on mature neurons in the adult rat hippocampus. We report an up-regulation in CX3CL1 protein expression in the CA1, CA3 and dentate gyrus of the rat hippocampus 2 h after spatial learning in the water maze task. Moreover, the same temporal increase in CX3CL1 was evident following long-term potentiation-inducing theta-burst stimulation in the dentate gyrus. At physiologically relevant concentrations, CX3CL1 inhibited LTP maintenance in the dentate gyrus. This attenuation in dentate LTP was lost in the presence of GABAA receptor/chloride channel antagonism. CX3CL1 also had opposing actions on glutamate-mediated rise in intracellular calcium in hippocampal organotypic slice cultures in the presence and absence of GABAA receptor/chloride channel blockade. Using primary dissociated hippocampal cultures, we established that CX3CL1 reduces glutamate-mediated intracellular calcium rises in both neurons and glia in a dose dependent manner. In conclusion, CX3CL1 is up-regulated in the hippocampus during a brief temporal window following spatial learning the purpose of which may be to regulate glutamate-mediated neurotransmission tone. Our data supports a possible role for this chemokine in the protective plasticity process of synaptic scaling.

  18. A 3D model of SARS_CoV 3CL proteinase and its inhibitors design by virtual screening

    Institute of Scientific and Technical Information of China (English)

    LUOCheng; CHENJing; LUOHai-Bin; CHENLi-Li; LIGuo-Wei; SUNTao; YUChang-Ying; YUELi-Duo; SHENJian-Hua; JIANGHua-Liang; XIONGBin; GUIChun-Shan; XUXiao-Ying; DUANWen-Hu; SHENJing-Kang; QINLei; SHITi-Liu; LIYi-Xue; CHENKai-Xian; LUOXiao-Min; SHENXu

    2003-01-01

    AIM:To constructed a three-dimensional (3D) model for the 3C like (3CL) proteinase of SARS coronavirus (SARS_CoV), and to design inhibitors of the 3CL proteinase based on the 3D model. METHODS: Bioinformatics analyses were performed to search the homologous proteins of the SARS_CoV 3CL proteinase from the GenBank and PDB database. A 3D model of the proteinase was constructed by using homology modeling technique. Targeting to the 3D model and its X-ray crystal structure of the main proteinase (Mpro) of transmissible gastroenteritis virus(TGEV), virtual screening was performed employing molecular docking method to identify possible 3CL proteinase inhibitors from small molecular databases. RESULTS:Sequence alignment indicated that the SARS_CoV 3CL proteinase was extremely homologous to TGEV Mpro, especially the substrate-binding pocket (active site). Accordingly, a 3D model for the SARS_CoV 3CL proteinase was constructed based on the crystal structure of TGEV Mpro. The 3D model adopts a similar fold of the TGEV mpro, its structure and binding pocket feature are almost as same as that of TGEV Mpro. The tested virtual screening indicated that 73 available proteinase inhibitors in the MDDR database might dock into both the binding pockets of the TGEV Mpro and the SARS_CoV 3CL proteinase. CONCLUSIONS:Either the 3D model of the SARS_CoV 3CL proteinase or the X-ray crystal stucture of the TGEV Mpro may be used as a starting point for design anti-SARS drugs. Screening the known proteinase inhibitors may be an appreciated shortcut to discover anti-SARS drugs.

  19. Using Cytochrome c{sub 3} to Make Selenium Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    ABDELOUAS,A.; FRANCO,R.; GONG,W.L.; LUTZE,W.; MOURA,I.; SHELNUTT,JOHN A.

    1999-11-24

    We report on a new method to make nanostructures, in this case selenium nanowires, in aqueous solution at room temperature. We used the protein cytochrome c{sub 3} to reduce selenate (SeO{sub 4}{sup 2{minus}}) to selenium (Se{sup 0}). Cytochrome c{sub 3} is known for its ability to catalyze reduction of metals including U{sup VI} {yields} U{sup IV}, Cr{sup VI} {yields} Cr{sup III}, Mo{sup VI} {yields} Mo{sup IV}, Cu{sup II} {yields} Cu{sup 0}, Pb{sup II} {yields} Pb{sup 0}, Hg{sup II} {yields} Hg{sup 0}. Nanoparticles of Se{sup 0} precipitated from an aqueous solution at room temperature, followed by spontaneous self-assembling into nanowires. Cytochrome c{sub 3} was extracted from the sulfate-reducing bacteria Desulfovibrio vulgaris (strain Holdenborough) and isolated by the procedure of DerVartanian and Legall.

  20. Preparative isolation of the fullerenes C{sub 60} and C{sub 70} and their analysis by high-performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Spitsyna, N.G.; Buravov, L.I.; Lobach, A.S. [Institute of Chemical Physics in Chernogolovka, Moscow (Russian Federation)

    1995-06-01

    In this work, the authors report a rapid and efficient method for the preparative isolation of fullerenes C{sub 60} and C{sub 70}. Liquid column chromatography on graphite and analysis by HPLC with a MILIKhROM-2 chromatograph is presented.

  1. Reduced CX3CL1 Secretion Contributes to the Susceptibility of Oral Leukoplakia-Associated Fibroblasts to Candida albicans

    Science.gov (United States)

    Cheng, Ran; Li, Duo; Shi, Xueke; Gao, Qinghong; Wei, Changlei; Li, Xiaoyu; Li, Yan; Zhou, Hongmei

    2016-01-01

    Candida leukoplakia (OLK) is a kind of oral leukoplakia combined with chronic candidal infection, which plays an important role in the malignant transformation of OLK. However, little is known about the etiology, including susceptibility of leukoplakia to candidal adhesion, invasion and infection. Some antimicrobial peptides secreted by oral epithelial cells or fibroblasts potentially have antifungal activities against Candida albicans (C. albicans). In this study, we established three co-culture models to simulate different C. albicans-fibroblasts interactions during progression of candida leukoplakia. The susceptibility of oral leukoplakia-associated fibroblasts (LKAFs) to C. albicans and its underlying mechanism were determined. Samples of 14 LKAFs and 10 normal fibroblasts (NFs) were collected. The co-culture models showed that LKAFs had promoted the adhesion, invasion, and survival of C. albicans compared with NFs. CX3CL1, a chemokine with antifungal activity, was less abundant in LKAFs than NFs. Overexpression of CX3CL1 via transfection in LKAFs could partly restore the resistance to C. albicans. We also showed that inhibition of ERK could suppress CX3CL1 secretion. While phosphor-ERK was inhibited in LKAFs compared with NFs. Besides, the mRNA expression of a shedding enzyme for CX3CL1, disintegrin and metalloproteinase domain (ADAM) 17 was decreased in LKAFs than NFs. In conclusion, LKAFs produced and secreted less CX3CL1 by inhibiting the ERK signaling pathway, thereby contributing to impaired cell resistance to C. albicans. PMID:27891323

  2. Reduced CX3CL1 secretion contributes to the susceptibility of oral leukoplakia-associated fibroblasts to Candida albicans

    Directory of Open Access Journals (Sweden)

    Ran Cheng

    2016-11-01

    Full Text Available Candida leukoplakia (OLK is a kind of oral leukoplakia combined with chronic candidal infection, which plays an important role in the malignant transformation of OLK. However, little is known about the etiology, including susceptibility of leukoplakia to candidal adhesion, invasion and infection. Some antimicrobial peptides secreted by oral epithelial cells or fibroblasts potentially have antifungal activities against Candida albicans (C. albicans. In this study, we established three co-culture models to simulate different C. albicans-fibroblasts interactions during progression of candida leukoplakia. The susceptibility of oral leukoplakia-associated fibroblasts (LKAFs to C. albicans and its underlying mechanism were determined. Samples of 14 LKAFs and 10 normal fibroblasts (NFs were collected. The co-culture models showed that LKAFs had promoted the adhesion, invasion, and survival of C. albicans compared with NFs. CX3CL1, a chemokine with antifungal activity, was less abundant in LKAFs than NFs. Overexpression of CX3CL1 via transfection in LKAFs could partly restore the resistance to C. albicans. We also showed that inhibition of ERK could suppress CX3CL1 secretion. While phosphor-ERK was inhibited in LKAFs compared with NFs. Besides, the expression of a shedding enzyme for CX3CL1, disintegrin and metalloproteinase domain (ADAM 17 was decreased in LKAFs than NFs. In conclusion, LKAFs produced and secreted less CX3CL1 by inhibiting the ERK signaling pathway, thereby contributing to impaired cell resistance to C. albicans.

  3. Preliminary study correlating CX3CL1/CX3CR1 expression with gastric carcinoma and gastric carcinoma perineural invasion.

    Science.gov (United States)

    Lv, Cheng-Yu; Zhou, Tao; Chen, Wei; Yin, Xin-Dao; Yao, Jian-Hong; Zhang, Yi-Fan

    2014-04-21

    To study the relationship between the CX3CL1 chemokine, its receptor CX3CR1, and gastric carcinoma/gastric carcinoma perineural invasion (PNI). Thirty cases of gastric carcinoma were surgically resected (radical resection or palliative resection) between February 2012 and July 2012. Tumour and tumour-adjacent tissues were evaluated for the presence of CX3CL1 (ELISA) and CX3CR1 (immunohistochemistry and Western blotting) in an effort to analyse the relationship between CX3CL1/CX3CR1 and gastric carcinoma/gastric carcinoma PNI. Of these 30 cases, 14 were PNI-positive (46.7%). No significant differences in CX3CL and CX3CR1 expression in tumour-adjacent tissues were found between the PNI positive and negative groups. Expression levels of CX3CL and CX3CR1 in tumour tissues were significantly higher than those in adjacent tissues (P gastric carcinoma as well as gastric carcinoma PNI.

  4. Dieckol, a SARS-CoV 3CL(pro) inhibitor, isolated from the edible brown algae Ecklonia cava.

    Science.gov (United States)

    Park, Ji-Young; Kim, Jang Hoon; Kwon, Jung Min; Kwon, Hyung-Jun; Jeong, Hyung Jae; Kim, Young Min; Kim, Doman; Lee, Woo Song; Ryu, Young Bae

    2013-07-01

    SARS-CoV 3CL(pro) plays an important role in viral replication. In this study, we performed a biological evaluation on nine phlorotannins isolated from the edible brown algae Ecklonia cava. The nine isolated phlorotannins (1-9), except phloroglucinol (1), possessed SARS-CoV 3CL(pro) inhibitory activities in a dose-dependently and competitive manner. Of these phlorotannins (1-9), two eckol groups with a diphenyl ether linked dieckol (8) showed the most potent SARS-CoV 3CL(pro) trans/cis-cleavage inhibitory effects (IC(50)s = 2.7 and 68.1 μM, respectively). This is the first report of a (8) phlorotannin chemotype significantly blocking the cleavage of SARS-CoV 3CL(pro) in a cell-based assay with no toxicity. Furthermore, dieckol (8) exhibited a high association rate in the SPR sensorgram and formed extremely strong hydrogen bonds to the catalytic dyad (Cys145 and His41) of the SARS-CoV 3CL(pro).

  5. Naringin Protects Against High Glucose-Induced Human Endothelial Cell Injury Via Antioxidation and CX3CL1 Downregulation

    Directory of Open Access Journals (Sweden)

    Guilin Li

    2017-08-01

    Full Text Available Background/Aims: The induction of endothelial injury by hyperglycemia in diabetes has been widely accepted. Naringin is a bio-flavonoid. Some studies showed that naringin alleviates diabetic complications, but the exact mechanisms by which naringin improves diabetic anomalies are not yet fully understood. The aim of this research was to study the protective effect of naringin on high glucose-induced injury of human umbilical vein endothelial cells (HUVECs. Methods: HUVECs were cultured with or without high glucose in the absence or presence of naringin for 5 days. The expression of CX3CL1 was determined by quantitative real-time RT-PCR (qPCR and western blot. The cellular bioenergetic analysis oxygen consumption rate (OCR was measured with a Seahorse Bioscience XF analyzer. Results: The production of reactive oxygen species (ROS, the expression of CX3CL1 and the level of AKT phosphorylation were increased in HUVECs cultured with high glucose compared with controls. However, naringin rescued these increases in ROS production, CX3CL1 expression and AKT phosphorylation. Nitric oxide (NO production and OCR were lower in the high glucose group, and naringin restored the changes induced by high glucose. Molecular docking results suggested that Naringin might interact with the CX3CL1 protein. Conclusion: Naringin protects HUVECs from high-glucose-induced damage through its antioxidant properties by downregulating CX3CL1 and by improving mitochondrial function.

  6. Ni3Cl2.1(OH)3.9·4H2O, the Ni analogue to Mg3Cl2(OH)4·4H2O.

    Science.gov (United States)

    Bette, Sebastian; Dinnebier, Robert E; Freyer, Daniela

    2014-05-05

    For the first time a basic transition-metal hydrate, Ni3Cl2.1(OH)3.9·4H2O, is found to be isostructural to a main-group metal phase, Mg3Cl2.0(OH)4.0·4H2O. The Ni phase was found as crystalline solid in the course of investigations into the formation of basic nickel(II) chloride phases at 25 and 40 °C in alkaline, concentrated nickel(II) chloride solutions. Ni3Cl2.1(OH)3.9·4H2O was characterized by thermal analysis, IR spectroscopy, scanning electron microscopy, and X-ray powder diffraction. The crystal structure was determined from high-resolution laboratory X-ray powder diffraction data. Ni3Cl2.1(OH)3.9·4H2O crystallizes in space group C2/m (12) with Z = 2, a = 14.9575(4) Å, b = 3.1413(1) Å, c = 10.4818(5) Å, β = 101.482(1)°, and V = 482.50(3) Å(3). The main building unit of the structure is an infinite triple chain of edge-linked distorted NiO6 octahedra. These chains are separated by interstitial one-dimensional zigzag chains of disordered Cl(-) ions and H2O molecules. The crystal structures of Ni3Cl2.1(OH)3.9·4H2O and the isostructural magnesium salt hydrate Mg3Cl2(OH)4·4H2O (2-1-4 phase) are compared in detail.

  7. Spectrophotometric Study of Adduct Formation Between [Co(Salen)PPh3]ClO4.H2O and [Co(7,7'-Dimethylsalen)PPh3]ClO4.H2O with Amines Donors in Acetonitrile

    OpenAIRE

    2010-01-01

    The equilibrium quotient of the adduct formation of [Co(Salen)PPh3]ClO4.H2O and [Co(7,7'-dimethylSalen)PPh3]ClO4.H2O, as acceptor with amines donors are studied by spectrophotometer. Thermodynamics of these pentacoordinate cobalt(III) Schiff-base complexes have been examined with n-butylamine, sec-butylamine, tert-butylamine, benzylamine and diethylamine in constant ionic strength of 0.1 M sodium perchlorate and acetonitrile solvent at room temperature. We aimed to investigate the effects of ...

  8. C{sub 60} fullerene decoration of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Demin, V. A., E-mail: victordemin88@gmail.com [Russian Academy of Sciences, Emanuel Institute of Biochemical Physics (Russian Federation); Blank, V. D.; Karaeva, A. R.; Kulnitskiy, B. A.; Mordkovich, V. Z. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Parkhomenko, Yu. N. [National University of Science and Technology MISiS (Russian Federation); Perezhogin, I. A.; Popov, M. Yu. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Skryleva, E. A. [National University of Science and Technology MISiS (Russian Federation); Urvanov, S. A. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Chernozatonskii, L. A. [Russian Academy of Sciences, Emanuel Institute of Biochemical Physics (Russian Federation)

    2016-12-15

    A new fully carbon nanocomposite material is synthesized by the immersion of carbon nanotubes in a fullerene solution in carbon disulfide. The presence of a dense layer of fullerene molecules on the outer nanotube surface is demonstrated by TEM and XPS. Fullerenes are redistributed on the nanotube surface during a long-term action of an electron beam, which points to the existence of a molecular bond between a nanotube and fullerenes. Theoretical calculations show that the formation of a fullerene shell begins with the attachment of one C{sub 60} molecule to a defect on the nanotube surface.

  9. Halogenation effects on electron collisions with CF3Cl, CF2Cl2, and CFCl3

    Science.gov (United States)

    Freitas, T. C.; Lopes, A. R.; Azeredo, A. D.; Bettega, M. H. F.

    2016-04-01

    We report differential and integral elastic cross sections for low-energy electron collisions with CF3Cl, CF2Cl2, and CFCl3 molecules for energies ranging from 0.1 eV to 30 eV. The calculations were performed using the Schwinger multichannel method with pseudopotentials in the static-exchange and static-exchange plus polarization approximations. The influence of the permanent electric dipole moment on the cross sections was included using the Born closure scheme. A very good agreement between our calculations and the experimental results of Jones [J. Chem. Phys. 84, 813 (1986)], Mann and Linder [J. Phys. B 25, 1621 (1992); 25, 1633 (1992)] and Hoshino et al. [J. Chem. Phys. 138, 214305 (2013)] was found. We also compare our results with the calculations of Beyer et al. [Chem. Phys. 255, 1 (2000)] using the R-matrix method, where we find good agreement with respect to the location of the resonances, and with the calculations of Hoshino et al. using the independent atom method with screening corrected additivity rule, where we find qualitative agreement at energies above 20 eV. Additional electronic structure calculations were carried out in order to help in the interpretation of the scattering results. The stabilization the lowest σ∗ resonance due to the exchange of fluorine by chlorine atoms (halogenation effect) follows a simple linear relation with the energy of the lowest unoccupied molecular orbitals and can be considered as a signature of the halogenation effect.

  10. Study on Substrate Specificity at Subsites for Severe Acute Respiratory Syndrome Coronavirus 3CL Protease

    Institute of Scientific and Technical Information of China (English)

    Yu-Fei SHAN; Gen-Jun XU

    2005-01-01

    Autocleavage assay and peptide-based cleavage assay were used to study the substrate specificity of 3CL protease from the severe acute respiratory syndrome coronavirus. It was found that the recognition between the enzyme and its substrates involved many positions in the substrate, at least including residues from P4 to P2'. The deletion of either P4 or P2' residue in the substrate would decrease its cleavage efficiency dramatically. In contrast to the previous suggestion that only small residues in substrate could be accommodated to the S 1' subsite, we have found that bulky residues such as Tyr and Trp were also acceptable.In addition, based on both peptide-based assay and autocleavage assay, Ile at the P1' position could not be hydrolyzed, but the mutant L27A could hydrolyze the Ile peptide fragment. It suggested that there was a stereo hindrance between the S 1' subsite and the side chain of Ile in the substrate. All 20 amino acids except Pro could be the residue at the P2' position in the substrate, but the cleavage efficiencies were clearly different. The specificity information of the enzyme is helpful for potent anti-virus inhibitor design and useful for other coronavirus studies.

  11. Charge-transfer reactions between C{sub 60} and hydrophilic solutes

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrijevic, N.M.; Nedeljkovic, J.M.; Saponjic, Z.V. [Institute for Nuclear Sciences ``Vinca``, Belgrade (Yugoslavia)

    1998-10-01

    Two different procedures for dissolving fullerene molecule C{sub 60} into aqueous solutions have been developed. Embedding C{sub 60} clusters into a water-soluble host molecule of {gamma}-cyclodextrin resulted in relatively low concentration of C{sub 60} (5-10 {mu}M). Prepare of a stable ionic surfactant/water/oil microemulsion provided a method for dissolving C{sub 60} in relatively high concentrations (1 mM). In both cases charge-transfer reactions between hydrophobic molecule of C{sub 60} and hydrophilic solutes were examined. Anion radical C{sub 60}{sup -} was detected in reaction with radiolytically produced radicals (e{sub aq}{sup -}, (CH{sub 3}){sub 2}COH or MV{sup +}), and in reaction with excess electrons stored onto nanometer-sized metal (Ag) or quantized semiconductor (TiO{sub 2}) particles. (orig.) 33 refs.

  12. Pb2 BO3 Cl: A Tailor-Made Polar Lead Borate Chloride with Very Strong Second Harmonic Generation.

    Science.gov (United States)

    Zou, Guohong; Lin, Chensheng; Jo, Hongil; Nam, Gnu; You, Tae-Soo; Ok, Kang Min

    2016-09-19

    A meticulously designed, polar, non-centrosymmetric lead borate chloride, Pb2 BO3 Cl, was synthesized using KBe2 BO3 F2 (KBBF) as a model. Single-crystal X-ray diffraction revealed that the structure of Pb2 BO3 Cl consists of cationic [Pb2 (BO3 )](+) honeycomb layers and Cl(-) anions. Powder second harmonic generation (SHG) measurements on graded polycrystalline Pb2 BO3 Cl indicated that the title compound is phase-matchable (type I) and exhibits a remarkably strong SHG response, which is approximately nine times stronger than that of potassium dihydrogen phosphate, and the largest efficiency observed in materials with structures similar to KBBF. Further characterization suggested that the compound melts congruently at high temperature and has a wide transparency window from the near-UV to the mid-IR region.

  13. Interaction of fullerene C{sub 60} with 3-amino-1-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Gol`dshleger, N.F.; Lobach, A.S.; Astakhova, A.S. [Institute of Chemical Physics in Chernogolovka, Moscow (Russian Federation)] [and others

    1994-12-01

    The C{sub 60} radical anions formed in the interaction of C{sub 60} with 3-amino-1-propanol under a vacuum were characterized by ESR and near-IR spectroscopy. In the air, a compound was obtained whose composition corresponds to the C{sub 60}:NH{sub 2}CH{sub 2}CH{sub 2}CH{sub 2}OH=1:3.

  14. Application of C{sub 60}, C{sub 72} and carbon nanotubes as anode for lithium-ion batteries: A DFT study

    Energy Technology Data Exchange (ETDEWEB)

    Najafi, Meysam, E-mail: meysamnajafi2016@gmail.com

    2017-07-01

    The application of C{sub 60}, C{sub 72}, CNT (8, 0) and CNT (10, 0) as anode materials for Lithium-ion batteries were investigated by density functional theory (DFT) calculations. Results show that the average values of voltage cell (V{sub cell}) and adsorption energy (E{sub ad}) of CNT (8, 0) and CNT (10, 0) were higher than C{sub 60} and C{sub 72} ca 0.327 V and 6.52 kcal/mol, respectively. The NH{sub 2} functionalization of studied nanostructures as a strategy to improve the performance of these systems as anode materials of Lithium-ion batteries were investigated. Results show that, NH{sub 2} functionalization of studied nanostructures increase the average values of voltage cell and adsorption energy ca 0.197 V and 8.20 kcal/mol, respectively. Obtained results propose that NH{sub 2} functionalized C{sub 72} and CNT (10, 0) have larger V{sub cell} and E{sub ad} values and therefore these nanostructures have higher potential as anode material for Lithium-ion battery. - Highlights: • C{sub 60} and CNT (10, 0) as anode materials for Lithium-ion batteries were investigated. • V{sub cell} and E{sub ad} of CNT (8, 0) and CNT (10, 0) were higher than C{sub 60} and C{sub 72} ca. • NH{sub 2} functionalization of C{sub 60} improve the performance of it as anode materials of Lithium-ion batteries.

  15. Synthesis of biological markers in fossil fuels. 4. C/sub 27/, C/sub 28/, and C/sub 29/ 13. beta. ,17. cap alpha. (H)-diasteranes

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, P.E.; Nelson, D.A.; Watt, D.S.; Reibenspies, J.H.; Anderson, O.P.; Seifert, W.K.; Moldowan, J.M.

    1985-12-27

    The rearrangement of 5-cholestene to (20epsilon)-13(17)-diacholestenes, separation of C-20 epimers, and further reduction provided an unambiguous synthesis of the biomarkers (20R)- and (20S)-13..beta..,17..cap alpha..(H)-diacholestanes. Repetition of this sequence using (24R)-5-campestene or (24R)-5-stigmastene provided the analogous C/sub 28/ and C/sub 29/ diasteranes. 15 references, 1 figure.

  16. Influence of magnesium sulfate on HCO3/Cl transmembrane exchange rate in human erythrocytes.

    Science.gov (United States)

    Chernyshova, Ekaterina S; Zaikina, Yulia S; Tsvetovskaya, Galina A; Strokotov, Dmitry I; Yurkin, Maxim A; Serebrennikova, Elena S; Volkov, Leonid; Maltsev, Valeri P; Chernyshev, Andrei V

    2016-03-21

    Magnesium sulfate (MgSO4) is widely used in medicine but molecular mechanisms of its protection through influence on erythrocytes are not fully understood and are considerably controversial. Using scanning flow cytometry, in this work for the first time we observed experimentally (both in situ and in vitro) a significant increase of HCO3(-)/Cl(-) transmembrane exchange rate of human erythrocytes in the presence of MgSO4 in blood. For a quantitative analysis of the obtained experimental data, we introduced and verified a molecular kinetic model, which describes activation of major anion exchanger Band 3 (or AE1) by its complexation with free intracellular Mg(2+) (taking into account Mg(2+) membrane transport and intracellular buffering). Fitting the model to our in vitro experimental data, we observed a good correspondence between theoretical and experimental kinetic curves that allowed us to evaluate the model parameters and to estimate for the first time the association constant of Mg(2+) with Band 3 as KB~0.07mM, which is in agreement with known values of the apparent Mg(2+) dissociation constant (from 0.01 to 0.1mM) that reflects experiments on enrichment of Mg(2+) at the inner erythrocyte membrane (Gunther, 2007). Results of this work partly clarify the molecular mechanisms of MgSO4 action in human erythrocytes. The method developed allows one to estimate quantitatively a perspective of MgSO4 treatment for a patient. It should be particularly helpful in prenatal medicine for early detection of pathologies associated with the risk of fetal hypoxia.

  17. Human cytomegalovirus chemokine receptor US28 induces migration of cells on a CX3CL1-presenting surface

    DEFF Research Database (Denmark)

    Hjortø, Gertrud M; Kiilerich-Pedersen, Katrine; Selmeczi, David

    2013-01-01

    Human cytomegalovirus (HCMV)-encoded G protein-coupled-receptor US28 is believed to participate in virus dissemination through modulation of cell migration and immune evasion. US28 binds different CC chemokines and the CX3C chemokine CX3CL1. Membrane-anchored CX3CL1 is expressed by immune......-activated endothelial cells, causing redirection of CX3CR1-expressing leukocytes in the blood to sites of infection. Here, we used stable transfected cell lines to examine how US28 expression affects cell migration on immobilized full-length CX3CL1, to model how HCMV-infected leukocytes interact with inflamed...... endothelium. We observed that US28-expressing cells migrated more than CX3CR1-expressing cells when adhering to immobilized CX3CL1. US28-induced migration was G protein-signalling dependent and was blocked by the phospholipase Cβ inhibitor U73122 and the intracellular calcium chelator BAPTA-AM. In addition...

  18. CX3CL1, a chemokine finely tuned to adhesion: critical roles of the stalk glycosylation and the membrane domain

    Directory of Open Access Journals (Sweden)

    Mariano A. Ostuni

    2014-11-01

    Full Text Available The multi-domain CX3CL1 transmembrane chemokine triggers leukocyte adherence without rolling and migration by presenting its chemokine domain (CD to its receptor CX3CR1. Through the combination of functional adhesion assays with structural analysis using FRAP, we investigated the functional role of the other domains of CX3CL1, i.e., its mucin stalk, transmembrane domain, and cytosolic domain. Our results indicate that the CX3CL1 molecular structure is finely adapted to capture CX3CR1 in circulating cells and that each domain has a specific purpose: the mucin stalk is stiffened by its high glycosylation to present the CD away from the membrane, the transmembrane domain generates the permanent aggregation of an adequate amount of monomers to guarantee adhesion and prevent rolling, and the cytosolic domain ensures adhesive robustness by interacting with the cytoskeleton. We propose a model in which quasi-immobile CX3CL1 bundles are organized to quickly generate adhesive patches with sufficiently high strength to capture CX3CR1+ leukocytes but with sufficiently low strength to allow their patrolling behavior.

  19. Hydrogen sulfide inhibits the development of atherosclerosis with suppressing CX3CR1 and CX3CL1 expression.

    Directory of Open Access Journals (Sweden)

    Huili Zhang

    Full Text Available Hydrogen sulfide, as a novel gaseous mediator, has been suggested to play a key role in atherogenesis. However, the precise mechanisms by which H(2S affects atherosclerosis remain unclear. Therefore, the present study aimed to investigate the potential role of H(2S in atherosclerosis and the underlying mechanism with respect to chemokines (CCL2, CCL5 and CX3CL1 and chemokine receptors (CCR2, CCR5, and CX3CR1 in macrophages. Mouse macrophage cell line RAW 264.7 or mouse peritoneal macrophages were pre-incubated with saline or NaHS (50 µM, 100 µM, 200 µM, an H(2S donor, and then stimulated with interferon-γ (IFN-γ or lipopolysaccharide (LPS. It was found that NaHS dose-dependently inhibited IFN-γ or LPS-induced CX3CR1 and CX3CL1 expression, as well as CX3CR1-mediated chemotaxis in macrophages. Overexpression of cystathionine γ-lyase (CSE, an enzyme that catalyzes H(2S biosynthesis resulted in a significant reduction in CX3CR1 and CX3CL1 expression as well as CX3CR1-mediated chemotaxis in stimulated macrophages. The inhibitory effect of H(2S on CX3CR1 and CX3CL1 expression was mediated by modulation of proliferators-activated receptor-γ (PPAR-γ and NF-κB pathway. Furthermore, male apoE(-/- mice were fed a high-fat diet and then randomly given NaHS (1 mg/kg, i.p., daily or DL-propargylglycine (PAG, 10 mg/kg, i.p., daily. NaHS significantly inhibited aortic CX3CR1 and CX3CL1 expression and impeded aortic plaque development. NaHS had a better anti-atherogenic benefit when it was applied at the early stage of atherosclerosis. However, inhibition of H(2S formation by PAG increased aortic CX3CR1 and CX3CL1 expression and exacerbated the extent of atherosclerosis. In addition, H(2S had minimal effect on the expression of CCL2, CCL5, CCR2 and CCR5 in vitro and in vivo. In conclusion, these data indicate that H(2S hampers the progression of atherosclerosis in fat-fed apoE(-/- mice and downregulates CX3CR1 and CX3CL1 expression on macrophages and

  20. NMR studies of alkali C{sub 60} superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Stenger, V.A.; Recchia, C.; Pennington, C.H. [Ohio State Univ., Columbus, OH (United States)] [and others

    1994-12-01

    The authors report {sup 13}C, {sup 87}Rb, {sup 39}K, and {sup 133}Cs nuclear magnetic resonance (NMR) measurements of lineshapes, Knight shifts, and spin-lattice relaxation rates in the normal and superconducting states of M{sub 3}C{sub 60}, where M{sub 3} = Rb{sub 3}, K{sub 3}, Rb{sub 2}K, RbK{sub 2}, Rb{sub 2}Cs, and RbCs{sub 2}. Measurements are used as a guide to a new ammonia solvent synthesis technique. Temperature dependence of the superconducting state electron spin susceptibility is found to follow BCS weak coupling predictions. The issue of the Hebel-Slichter coherence peak is addressed.

  1. Quenching excited triplet C{sub 60} fullerene by tetracyanoethylene in benzonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Nadtochenko, V.A.; Denisov, N.N.; Rubtsov, I.V.; Lobach, A.S.; Moravsky, A.P. [Institute of Chemical Physics in Chernogolovka, Moscow (Russian Federation)

    1994-01-01

    The main photophysical properties of C{sub 60} fullerene: The absorption spectra of excited singlet C{sub 60}, the inter-combinational conversion time, the quantum yield of triplet C{sub 60}, the triplet-triplet absorption spectra, and the channels and rate constants of the deactivation of triplet C{sub 60} have been established. The photochemical properties of C{sub 60} fullerene have been investigated to a lesser degree. C{sub 60} is known to be readily reduced (E{sub 1/2} = {minus}0.4 in relation to Ag/Ag{sup +}), in particular, photochemically. For example, photoexcitation of charge-transfer complexes of C{sub 60} with amines gives the radical anion C{sup {minus}}{sub 60} which is also formed in reactions of photoexcited C{sub 60} fullerene. The formation of the radical cation C{sup +}{sub 60} under the action of light has been detected in the reaction with colloidal TiO{sub 2}. The radical ion C{sup +}{sub 60} has been obtained in a homogeneous photochemical process: the reaction of unexcited C{sub 60} with excited singlet N-methylacridinium hexafluorophosphate or with the biphenyl radical cation generated in the reaction with excited singlet N-methylacridinium hexafluorophosphate. The formation of C{sup +}{sub 60} with an electron acceptor in a homogeneous process has not so far been observed. The purpose of this work has been to study the quenching of triplet {sup 3}C{sub 60} with an electron acceptor, tetracyanoethylene (TCNE), which is known to oxidize unsaturated or aromatic hydrocarbons in photochemical reactions.

  2. Cross sections for elastic scattering of electrons by CF3Cl, CF2Cl2, and CFCl3.

    Science.gov (United States)

    Hoshino, M; Horie, M; Kato, H; Blanco, F; García, G; Limão-Vieira, P; Sullivan, J P; Brunger, M J; Tanaka, H

    2013-06-07

    Differential, integral, and momentum transfer cross sections have been determined for the elastic scattering of electrons from the molecules CF3Cl, CF2Cl2, and CFCl3.With the help of a crossed electron beam-molecular beam apparatus using the relative flow technique, the ratios of the elastic differential cross sections (DCSs) of CF3Cl, CF2Cl2, and CFCl3 to those of He were measured in the energy region from 1.5 to 100 eV and at scattering angles in the range 15° to 130°. From those ratios, the absolute DCSs were determined by utilizing the known DCS of He. For CF3Cl and CF2Cl2, at the common energies of measurement, we find generally good agreement with the results from the independent experiments of Mann and Linder [J. Phys. B 25, 1621 (1992); and ibid. 25, 1633 (1992)]. In addition, as a result of progressively substituting a Cl-atom, undulations in the angular distributions have been found to vary in a largely systematic manner in going from CF4 to CF3Cl to CF2Cl2 to CFCl3 and to CCl4. These observed features suggest that the elastic scattering process is, in an independently additive manner, dominated by the atomic-Cl atoms of the molecules. The present independent atom method calculation typically supports the experimental evidence, within the screened additivity rule formulation, for each species and for energies greater than about 10-20 eV. Integral elastic and momentum transfer cross sections were also derived from the measured DCSs, and are compared to the other available theoretical and experimental results. The elastic integral cross sections are also evaluated as a part of their contribution to the total cross section.

  3. Concentration quenching of Eu{sup 2+} doped Ca{sub 2}BO{sub 3}Cl

    Energy Technology Data Exchange (ETDEWEB)

    Seed Ahmed, H.A.A. [Department of Physics, University of the Free State, Bloemfontein, ZA 9300 (South Africa); Department of Physics, University of Khartoum, Khartoum (Sudan); Swart, H.C. [Department of Physics, University of the Free State, Bloemfontein, ZA 9300 (South Africa); Bergman, Peber [Department of Physics, Chemistry and Biology, Linköping University, Linköping (Sweden); Kroon, R.E., E-mail: KroonRE@Uufs.ac.za [Department of Physics, University of the Free State, Bloemfontein, ZA 9300 (South Africa)

    2016-03-15

    Highlights: • Ca{sub 2}BO{sub 3}Cl doped with Eu{sup 2+} prepared by solid state reaction. • Concentration quenching studied by intensity and lifetime measurements. • Accurate determination of the critical transfer distance. • Interaction mechanism verified to be dipole–dipole interactions. - Abstract: With the aim of determining the concentration quenching mechanism of Eu{sup 2+} doped Ca{sub 2}BO{sub 3}Cl, a series of phosphors with a varied Eu{sup 2+} concentration (Ca{sub 2−x}BO{sub 3}Cl:xEu{sup 2+}) was synthesized by the solid state reaction method. The phase structure was determined by X-ray diffraction. Photoluminescence (PL) measurements showed broad excitation and emission signatures of the allowed f–d transition of Eu{sup 2+} ions. The PL emission intensity was found to be increased by increasing the concentration of Eu{sup 2+} ions up to x = 0.03 and then decreased as a result of the concentration quenching effect. The lifetime of the emission from the Eu{sup 2+} ions was measured and the decrease in the lifetime with increasing Eu{sup 2+} concentration confirmed that non-radiative energy transfer occurred between Eu{sup 2+} ions. From the luminescence data, the value of the critical transfer distance was calculated as 1.5 nm and the corresponding concentration quenching mechanism was verified to be a dipole–dipole interaction.

  4. Hybrid Quantum Mechanical/Molecular Mechanics Study of the SN2 Reaction of CH3Cl+OH- in Water

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Hongyun; Wang, Dunyou; Valiev, Marat

    2011-11-03

    The SN2 mechanism for the reaction of CH3Cl + OH- in aqueous solution was investigated using combined quantum mechanical and molecular mechanics methodology. We analyzed structures of reactant, transition and product states along the reaction pathway. The free energy profile was calculated using the multi-layered representation with the DFT and CCSD(T) level of theory for the quantum-mechanical description of the reactive region. Our results show that the aqueous environment has a significant impact on the reaction process. We find that solvation energy contribution raises the reaction barrier by ~18.9 kcal/mol and the reaction free energy by ~24.5 kcal/mol. The presence of the solvent also induces perturbations in the electronic structure of the solute leading to an increase of 3.5 kcal/mol for the reaction barrier and a decrease of 5.6 kcal/mol for the reaction free energy respectively. Combining the results of two previous calculation results on CHCl3 + OH- and CH2Cl2 + OH- reactions in water, we demonstrate that increase in the chlorination of the methyl group (from CH3Cl to CHCl3) is accompanied by the decrease in the free energy reaction barrier, with the CH3Cl + OH- having the largest barrier among the three reactions.

  5. Stability of functionalized C{sub 60} paramagnetic dimers and monomers

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Michael [Armament Research Development and Engineering Center, Picatinny, NJ 07806-5000 (United States); Owens, Frank J., E-mail: owensfj@gmail.com [Department of Physics, Hunter College, City University of New York, 695 Park Ave., NY 10065 (United States)

    2012-02-06

    Highlights: Black-Right-Pointing-Pointer DFT is used to calculate the bond dissociation energy of functionalized C{sub 60} dimers. Black-Right-Pointing-Pointer The results show the dimers would not be stable above room temperature. Black-Right-Pointing-Pointer The calculations indicate the observed magnetism cannot be due to C{sub 60} dimers. Black-Right-Pointing-Pointer Because of their higher stability the ferromagnetism is likely due to X-C{sub 60} monomers. - Abstract: Density functional theory is used to calculate the bond dissociation energy to cleave the C{sub 60}=C{sub 60} bond of the paramagnetic X-C{sub 60}=C{sub 60}-X and X-C{sub 60}=C{sub 60} dimers where X is F, OH, O and H. The results show that these dimers would not be stable much above room temperature and therefore cannot constitute the paramagnetic phase needed to form the observed ferromagnetism which has been shown to be stable up to 800 K. The calculated bond dissociation energies to remove an F, OH or H from a single C{sub 60} are large suggesting that they could be the source of the unpaired spin needed for the high temperature ferromagnetism.

  6. Varying stress of SiOsub>xsub>Csub>ysub> thin films deposited by plasma polymerization.

    Science.gov (United States)

    Liao, Wei-Bo; Chang, Ya-Chen; Jaing, Cheng-Chung; Cheng, Ching-Long; Lee, Cheng-Chung; Wei, Hung-Sen; Kuo, Chien-Cheng

    2017-02-01

    SiOsub>xsub>Csub>ysub> thin films were deposited by plasma polymerization. The stress of the deposited SiOsub>xsub>Csub>ysub> thin films can be modified by adjusting the beam current, the anode voltage, and the flow rate of hexamethyldisiloxane (HMDSO) gas and oxygen. Reducing the beam current or increasing the flow rate of HMDSO gas increased the linear/cage structure ratio and turned the stress of the SiOsub>xsub>Csub>ysub> thin films from compressive to tensile. The linear/cage structure ratio can be adjusted by changing the composite parameter, W[FM]sub>csub>/[FM]sub>msub>, to control the stress of the deposited plasma polymer films. Multilayers of TiOsub>2sub>/SiOsub>2sub>/TiOsub>2sub> were coated on a SiOsub>xsub>Csub>ysub> plasma polymer film herein, reducing their stress by 70% from 0.06 to 0.018 GPa. The refractive index is 1.55, and the absorption coefficient is less than 10-4 at 550 nm of the SiOsub>xsub>Csub>ysub> films. Superior optical performances of SiOsub>xsub>Csub>ysub> thin films make their use in optical thin films.

  7. Transmission properties of C{sub 60} ions through micro- and nano-capillaries

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchida, Hidetsugu, E-mail: tsuchida@nucleng.kyoto-u.ac.jp [Quantum Science and Engineering Center, Kyoto University, Uji, Kyoto 611-0011 (Japan); Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Majima, Takuya [Quantum Science and Engineering Center, Kyoto University, Uji, Kyoto 611-0011 (Japan); Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Tomita, Shigeo [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Sasa, Kimikazu [Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Narumi, Kazumasa; Saitoh, Yuichi; Chiba, Atsuya; Yamada, Keisuke [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Hirata, Koichi [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Shibata, Hiromi [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Itoh, Akio [Quantum Science and Engineering Center, Kyoto University, Uji, Kyoto 611-0011 (Japan); Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan)

    2013-11-15

    We apply the capillary beam-focusing method for the C{sub 60} fullerene projectiles in the velocity range between 0.14 and 0.2 a.u. We study the C{sub 60} transmission properties through two different types of capillaries: (1) borosilicate glass microcapillary with an outlet diameter of 5.5 μm, and (2) Al{sub 2}O{sub 3} multi-capillary foil with a pore size of about 70 nm and a high aspect ratio of about 750. We measured the transmitted particle composition by using the electrostatic deflection method combined with the microchannel plate imaging technique. For the experiments with the single microcapillary, the main transmission component is found to be primary C{sub 60} beams that are focused in the area equal to the capillary outlet diameter. Minor components are charge-exchanged C{sub 60} ions and charged or neutral fragments (fullerene-like C{sub 60-2m} and small C{sub n} particles), and their fractions decrease with decreasing the projectile velocity. It is concluded that the C{sub 60} transmission fraction is considerably high for both types of the capillaries in the present velocity range.

  8. The differential effects of CO{sub 2} on relative growth rates of a C{sub 3} and C{sub 4} plant

    Energy Technology Data Exchange (ETDEWEB)

    Grise, D.J.; Sage, R.F. [Univ. of Georgia, Athens, GA (United States)]|[Univ. of Toronto, Ontario (Canada)

    1995-09-01

    We examined growth and allocation in Chenopodium album (C{sub 3}) and Amaranthus hybridus (C{sub 4}) at three CO{sub 2} levels (350, 750 and 1000 {mu}bar CO{sub 2}), at 34{degrees}C. Although net assimilation rate increased at higher than current ambient CO{sub 2} treatments for Chenopodium, relative growth rates for this species were significantly lower (P<0.001) than for Amaranthus at all CO{sub 2} treatments. However, the nature of the difference in relative growth rate changed across CO{sub 2} treatments. At 350 and 750 {mu}bar CO{sub 2}, differences in relative growth rates between species were not linearly maintained throughout the course of the experiment, the difference in relative growth rates between species was larger at the start of the experiment than at the end of the experiment. At 1000 {mu}bar CO{sub 2}, the difference in relative growth rate between species was linearly maintained throughout the course of the experiment. In this treatment, the pattern of relative growth rate for the C{sub 3} plant is the same as that of the C{sub 4} plant. On the basis of this experiment, we predict, at 34{degrees}C, the C{sub 3} plant will not successfully compete with the C{sub 4} plant at 350 or 750 {mu}bar CO{sub 2}, but might be able to compete successfully at 1000 {mu}bar CO{sub 2}.

  9. Comparison of hydrocarbon gases (C{sub 1}-C{sub 5}) production from Carboniferous Donets (Ukraine) and Cretaceous Sabinas (Mexico) coals

    Energy Technology Data Exchange (ETDEWEB)

    Alsaab, D.; Elie, M.; Izart, A.; Martinez, L. [G2R, Nancy - Universite, CNRS, CREGU, BP-239, 54506 Vandoeuvres-les-Nancy (France); Sachsenhofer, R.F. [Institut fuer Geowissenschaften, Montanuniversitaet Leoben, Peter-Tunner-Strasse 5, A-8700 Leoben (Austria); Privalov, V.A. [Donetsk National Technical University, Artem str., 58, UA-83000 Donetsk (Ukraine); Suarez-Ruiz, I. [Instituto Nacional del Carbon - (INCAR) - CSIC. Ap.Co., 73, 33080-Oviedo (Spain)

    2008-04-03

    The main purpose of this contribution is to compare the ability of Carboniferous coals from the Donets Basin of the Ukraine and Cretaceous coal from the Sabinas Basin of the Mexico to generate hydrocarbon gases (C{sub 1}-C{sub 5}). Two bituminous coals from the Donets Basin (2c10YD and 1l1Dim; 0.55 and 0.65%R{sub r} respectively) and one bituminous coal from the Sabinas Basin (Olmos, 0.92%R{sub r}) were studied using heating experiments in a confined-pyrolysis system. The highest rank reached during the heating experiments corresponds to the anthracite stage (2.78 and 2.57%R{sub r}) for the 2c10YD and 1l1Dim coals and (2.65%R{sub r}) for the Olmos coal. The composition of the generated (C{sub 1}-C{sub 5}) gases was evaluated using a thermodesorption-multidimensional gas chromatography. The results show that the Carboniferous Donets coals produced more wet gas and methane during pyrolysis than the Cretaceous Olmos coal. This is probably due to their higher liptinite (6-20%) and collodetrinite content and to the loss of a major part of the petroleum potential of the Olmos coal during natural coalification. C{sub 2}-C{sub 5} compounds are mainly derived from the cracking of liquid hydrocarbons. Ethane is the most stable compound and formed from the cracking of higher hydrocarbon component. Large amounts of methane (up to 81 mg/g coal for the Donets coals and 50 mg/g coal for the Sabinas coal) were formed at high temperatures by cracking of previously formed heavier hydrocarbons and by dealkylation of the coal matrix. A linear relationship was observed between methane generation and the maturity level of both coal types. (author)

  10. Preparation and surface enhanced Raman scattering behavior of Ag-coated C{sub 60} nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Shi-Zhao; Yin, Die-er; Li, Xiangqing; Mu, Jin, E-mail: mujin@sit.edu.cn

    2013-12-01

    Ag-coated C{sub 60} nanoclusters were prepared and characterized with X-ray diffraction, transmission electron microscopy and nitrogen adsorption–desorption isotherm measurement. The Ag-coated C{sub 60} nanoclusters were assembled on the glass substrate to form a thin film using the layer-by-layer technique. Meanwhile, the surface enhanced Raman scattering (SERS) of musk xylene adsorbed on the film of Ag-coated C{sub 60} nanoclusters was explored. The results indicated that the film of Ag-coated C{sub 60} nanoclusters was a unique SERS-active substrate with a detection limit of 10{sup −9} mol L{sup −1} for musk xylene. Furthermore, the surface enhanced mechanisms were discussed preliminarily.

  11. Mechanical characterization of C{sub 60} whiskers by MEMS bend testing

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, M P; Lucyszyn, S [Optical and Semiconductor Devices Group, Department of Electrical and Electronic Engineering, Imperial College London, Exhibition Road, London, SW7 2AZ (United Kingdom)], E-mail: s.lucyszyn@imperial.ac.uk

    2009-04-01

    Little has been published on the mechanical characteristics of C{sub 60} whiskers, due to the inherent difficulties in physically mounting such small test samples. Earlier reported results suggested Young's modulus values of 32 and 54 GPa, with 130 and 160 micron diameter C{sub 60} nanowhiskers, respectively, using compressive deformation techniques. In our work, an experimental bespoke silicon-based microelectromechanical system has been developed to extract an other value. 1th as been found, through parameter extraction techniques, that a Young's modulus of only {approx} 2 GPa is obtained with a C{sub 60} whisker having a diameter of 4 microns. By including the previously published data points, there is now strong evidence to suggest an inverse proportionality relationship between the Young's modulus and the diameter of a C{sub 60} whisker.

  12. Possibility of gas sensor based on C{sub 20} molecular devices

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Wenkai [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Yang, Chuanlu, E-mail: yangchuanlu@126.com [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Zou, Dongqing [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Sun, Zhaopeng [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Ji, Guomin [Electrical and Computer Engineering, The University of Oklahoma, Norman, Tulsa, OK 74078 (United States)

    2017-06-09

    We theoretically investigate the possibility of diatomic gas detection (NO, CO, O{sub 2}) by making use of the transport properties of the C{sub 20} molecular junctions. The calculations are performed by using nonequilibrium Green's function (NEGF) formalism in combination with density functional theory (DFT). In this work, we systematically study the most stable adsorption structural configurations, adsorption energy, and the transport properties on C{sub 20} molecular junctions with these diatomic gas molecules. It is found that NO and O{sub 2} gas molecule can be detected selectively. We suggest its possibility of nanosensors for highly sensitive and selective based on C{sub 20} molecular junction systems. - Highlights: • The most favorable adsorption site is investigated. • The mechanism of gas sensors is revealed. • NO and O{sub 2} gas molecules can be detected by C{sub 20} selectively.

  13. Electrical conductivity of reconstructed Si(111) surface with sodium-doped C{sub 60} layers

    Energy Technology Data Exchange (ETDEWEB)

    Tsukanov, D. A., E-mail: tsukanov@iacp.dvo.ru; Saranin, A. A. [Institute of Automation and Control Processes, FEB RAS, Vladivostok 690041 (Russian Federation); School of Natural Sciences, Far Eastern Federal University, Vladivostok 690950 (Russian Federation); Ryzhkova, M. V.; Borisenko, E. A. [Institute of Automation and Control Processes, FEB RAS, Vladivostok 690041 (Russian Federation); Zotov, A. V. [Institute of Automation and Control Processes, FEB RAS, Vladivostok 690041 (Russian Federation); School of Natural Sciences, Far Eastern Federal University, Vladivostok 690950 (Russian Federation); Department of Electronics, Vladivostok State University of Economics and Service, Vladivostok 690600 (Russian Federation)

    2015-01-05

    Electrical conductance of sodium-doped C{sub 60} ultra-thin layers (1–6 monolayers) grown on the Na-adsorbed Si(111)√3 × √3-Au surface has been studied in situ by four-point probe technique, combined with low-energy electron diffraction observations. Evidence of conductance channel formation through the C{sub 60} ultrathin layer is demonstrated as a result of Na dosing of 3 and 6 monolayers thick C{sub 60} layers. The observed changes in surface conductivity can be attributed to the formation of fulleride-like NaC{sub 60} and Na{sub 2}C{sub 60} compound layers.

  14. Studies of the mechanism of the olefin metathesis reaction and the process of active site formation on photoreduced molybdenum-silicate catalysts. 2. Productive and degenerative metathesis of C/sub 2/H/sub 4/-C/sub 2/D/sub 4/ and C/sub 3/H/sub 6/-C/sub 3/D/sub 6/ mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Elev, I.V.; Shelimov, B.N.; Kazanskii, V.B.

    1987-10-01

    The specific catalytic activity of photoreduced Mo/sup 4 +//SiO/sub 2/ samples has been compared for productive and degenerate metathesis reactions of C/sub 3/H/sub 6/-C/sub 3/D/sub 6/ and C/sub 2/H/sub 4/-C/sub 2/D/sub 4/ mixtures. It has been found, that, under comparable conditions, the rate of degenerate metathesis of ethylene is 4-5 times slower than the rate of productive metathesis of propylene, although the rate of degenerate metathesis of propylene is 5 x 10/sup 3/-10/sup 4/ times greater than its rate of productive metathesis. Based on these results, it is concluded that degenerate metathesis of propylene occurs via the involvement of secondary (ethylidene) carbenes.

  15. Decoherence free in subspace using Na at C{sub 60} as quantum qubit

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Xianghua; Bi Qiao; Guo Guangcan; Ruda, H.E

    2003-06-23

    An approach of quantum computing based on endohedral metallofullerenes has been discussed, which includes the construction of c{sup n}-Not logic gates and decoherence-free in the projected subspace to protect against the decoherence from the interaction with environment. As the special structure of Na at C{sub 60}, symmetrically alignment of n Na at C{sub 60} along z direction, we can construct the multiqubits under the control of the STM setups.

  16. Dissociative electron attachment and vibrational excitation of CF{sub 3}Cl: Effect of two vibrational modes revisited

    Energy Technology Data Exchange (ETDEWEB)

    Tarana, Michal [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588 (United States); JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440 (United States); Houfek, Karel; Horacek, Jiri [Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University in Prague, V Holesovickach 2, Prague (Czech Republic); Fabrikant, Ilya I. [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588 (United States); Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2011-11-15

    We present a study of dissociative electron attachment and vibrational excitation processes in electron collisions with the CF{sub 3}Cl molecule. The calculations are based on the two-dimensional nuclear dynamics including the C-Cl symmetric stretch coordinate and the CF{sub 3} symmetric deformation (umbrella) coordinate. The complex potential energy surfaces are calculated using the ab initio R-matrix method. The results for dissociative attachment and vibrational excitation of the umbrella mode agree quite well with experiment whereas the cross section for excitation of the C-Cl symmetric stretch vibrations is about a factor-of-three too low in comparison with experimental data.

  17. Fate of citalopram during water treatment with O3, ClO2, UV and fenton oxidation

    DEFF Research Database (Denmark)

    Hörsing, Maritha; Kosjek, Tina; Andersen, Henrik Rasmus;

    2012-01-01

    In the present study we investigate the fate of citalopram (CIT) at neutral pH using advanced water treatment technologies that include O3, ClO2 oxidation, UV irradiation and Fenton oxidation. The ozonation resulted in 80% reduction after 30 min treatment. Oxidation with ClO2 removed >90% CIT...... at a dosage of 0.1 mg L−1. During UV irradiation 85% reduction was achieved after 5 min, while Fenton with addition of 14 mg L−1 (Fe2+) resulted in 90% reduction of CIT. During these treatment experiments transformation products (TPs) were formed from CIT, where five compounds were identified by using high...

  18. Optical and photoelectrical studies of gold nanoparticle-decorated C{sub 60} films

    Energy Technology Data Exchange (ETDEWEB)

    Dmitruk, N.L., E-mail: dmitruk@isp.kiev.u [Institute for Physics of Semiconductors, National Academy of Sciences of Ukraine, 45 Nauki Prospect, Kyiv 03028 (Ukraine); Borkovskaya, O.Yu.; Mamykin, S.V.; Naumenko, D.O. [Institute for Physics of Semiconductors, National Academy of Sciences of Ukraine, 45 Nauki Prospect, Kyiv 03028 (Ukraine); Meza-Laguna, V. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, Ciudad Universitaria, A. P. 70-186, C. P. 04510 Mexico D.F. (Mexico); Basiuk Golovataya-Dzhymbeeva, E.V. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (UNAM), Circuito exterior S/N Ciudad Universitaria, A. P. 70-186, C. P. 04510 Mexico D.F. (Mexico); Lee, I. Puente [Facultad de Quimica, UNAM, Circuito de la Investigacion Cientifica, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)

    2010-01-01

    Optical and photoelectrical studies were performed on octane-1,8-dithiol cross-linked fullerene films, with supported gold nanoparticles (C{sub 60}-DT-Au). According to high-resolution transmission electron microscopy observations, the average size of obtained gold nanoparticles was about 5 nm, and the shape was spherical. The comparative investigation of optical properties of pristine and cross-linked with octane-1,8-dithiol C{sub 60} films, decorated with gold nanoparticles, found the difference in the extinction coefficient spectra, which was observed also in the photocurrent spectra of barrier heterostructure Au/C{sub 60}/Si. The analysis of dark current-voltage characteristics for Au/C{sub 60}/Si heterostructures showed that the model for them includes the barrier at the C{sub 60}/Si interface and internal barriers in the C{sub 60} layer, caused by the trapping centers. The hopping mechanism of the current transport in the C{sub 60} layer was supplemented with the Poole-Frenkel emission process on these centers, with the barrier height greater for the fullerene C{sub 60} film cross-linked with octane-1,8-dithiol.

  19. Negative ions produced in multicharged ions and C{sub 60} collisions

    Energy Technology Data Exchange (ETDEWEB)

    Martin, S; Bredy, R; Montagne, G; Bernard, J; Chen, L [Universite de Lyon, F-69622, Lyon (France); Universite Lyon 1, Villeurbanne (France); CNRS, UMR5579, LASIM (France); Salmoun, A [Laboratory of Instrumentation Measure and Control, Physics Department, Faculty of Sciences, University Chouaib Doukkali, BP 20 El Jadida (Morocco); Ma, X, E-mail: smartin@univ-lyon1.fr [Institute of Modern Physic, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2011-06-15

    We have measured the differential cross-sections in F{sup 3+}-C{sub 60} collisions at low velocity (v=0.18 a.u.). Using coincidence measurements between the ejected electron number and recoil ions, we have estimated the initial charge state of C{sub 60} parent ions associated with neutral outgoing projectiles to range from 4+ to 7+. We found that the formation of anions is correlated with the strong excitation of C{sub 60} (average excitation energy about 160 eV). The cross-section of the production of the anion has been found to be 25 a.u. This value is in agreement with the scenario of anion formation in two steps. In the first step, F{sup 3+} ions are neutralized by multicollision on the C{sub 60} surface. In the second step and at the exit part of the collision, the electron attachment process occurs. For the production of a stable anion, the capture of electrons on carbon must occur directly to the ground states of F{sup -}, giving many electron vacancies on C{sub 60}. This process explains the observation of strong electronic and vibronic excitations of C{sub 60} leading to electron emission and multifragmentation processes.

  20. Doping effects induced by potassium ion implantation in solid C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Trouillas, P. [Faculte des Sci., Limoges (France). Lab. d`Electronique des Polymers sous Faisceau Ionique; Moliton, A. [Faculte des Sci., Limoges (France). Lab. d`Electronique des Polymers sous Faisceau Ionique; Ratier, B. [Faculte des Sci., Limoges (France). Lab. d`Electronique des Polymers sous Faisceau Ionique

    1995-08-01

    Ion implantation is presented here as another technique for investigating the electrical properties of doped solid C{sub 60}. The conductivity and the thermopower have been studied versus the implantation parameters in order to investigate electrical transport phenomena which occur in implanted solid C{sub 60}, and thus prove doping effects. First results on ion implantation in C{sub 60} show a strong competition between damaging (induced by energetic ions) and doping effect (induced by charge transfer). Generally, electron transfers between the potassium atoms and the C{sub 60} molecules produce a conducting phase: up to x{approx} =0.1, metallic K{sub 3}C{sub 60} islands are dispersed in an insulating phase (virgin C{sub 60}); then, for x>0.1, damage plays a major role, leading to conduction paths through the samples (the saturation threshold x{approx} =0.1 is lower than in chemical doping due to the degradations). Potassium ion implantation with low energy (E{approx} =30 keV) and low fluence (D<10{sup 15} ions/cm{sup 2}) seems to provide the best implantation parameters for doping. Indeed, small ion size, low energy and low fluence are necessary in order to diminish the degradation effects. (orig.)

  1. Ca2BO3Cl:Ce3+, Tb3+: A novel tunable emitting phosphor for white light-emitting diode

    Institute of Scientific and Technical Information of China (English)

    Li Pan-Lai; Wang Yong-Sheng; Zhao Su-Ling; Zhang Fu-Jun; Xu Zheng

    2012-01-01

    Ca2BO3Cl:Ce3+,Ca2BO3Cl:Tb3+,and Ca2BO3Cl:Ce3+,Tb3+ phosphors are synthesized by a high temperature solid-state reaction.The emission intensity of Ce3+ or Tb3+ in Ca2BO3C1 is influenced by the Ce3+ or Tb3+ doping content,and the optimum concentrations of Ce3+ and Tb3+ are 0.03 mol and 0.05 mol,respectively.The concentration quenching effect of Ce3+ or Tb3+ in Ca2BO3Cl occurs,and the concentration quenching mechanism is d-d interaction for either Ce3+ or Tb3+.The Ca2BO3Cl:Ce3+,Tb3+ can produce colour emission from blue to green by properly tuning the relative ratio between Ce3+ and Tb3+,and the emission intensity of Tb3+ in Ca2BO3Cl can be enhanced by the energy transfer from Ce3+ to Tb3+.The results indicate that Ca2BO3Cl:Ce3+,Tb3+ may be a promising double emission phosphor for UV-based white light emitting diodes.

  2. CX3CR1 is expressed by human B lymphocytes and mediates [corrected] CX3CL1 driven chemotaxis of tonsil centrocytes.

    Directory of Open Access Journals (Sweden)

    Anna Corcione

    Full Text Available BACKGROUND: Fractalkine/CX(3CL1, a surface chemokine, binds to CX(3CR1 expressed by different lymphocyte subsets. Since CX(3CL1 has been detected in the germinal centres of secondary lymphoid tissue, in this study we have investigated CX(3CR1 expression and function in human naïve, germinal centre and memory B cells isolated from tonsil or peripheral blood. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate unambiguously that highly purified human B cells from tonsil and peripheral blood expressed CX(3CR1 at mRNA and protein levels as assessed by quantitative PCR, flow cytometry and competition binding assays. In particular, naïve, germinal centre and memory B cells expressed CX(3CR1 but only germinal centre B cells were attracted by soluble CX(3CL1 in a transwell assay. CX(3CL1 signalling in germinal centre B cells involved PI3K, Erk1/2, p38, and Src phosphorylation, as assessed by Western blot experiments. CX(3CR1(+ germinal centre B cells were devoid of centroblasts and enriched for centrocytes that migrated to soluble CX(3CL1. ELISA assay showed that soluble CX(3CL1 was secreted constitutively by follicular dendritic cells and T follicular helper cells, two cell populations homing in the germinal centre light zone as centrocytes. At variance with that observed in humans, soluble CX(3CL1 did not attract spleen B cells from wild type mice. OVA immunized CX(3CR1(-/- or CX(3CL1(-/- mice showed significantly decreased specific IgG production compared to wild type mice. CONCLUSION/SIGNIFICANCE: We propose a model whereby human follicular dendritic cells and T follicular helper cells release in the light zone of germinal centre soluble CX(3CL1 that attracts centrocytes. The functional implications of these results warrant further investigation.

  3. Morphology impact on oxygen sensing ability of Ru(dpp){sub 3}Cl{sub 2} containing biocompatible polymers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Susan Y.; Harrison, Benjamin S., E-mail: bharriso@wakehealth.edu

    2015-08-01

    Especially for tissue engineering applications, the diffusion of oxygen is a critical factor affecting spatial distribution and migration of cells. The cellular oxygen demand also fluctuates depending on tissue type and growth phase. Sensors that determine dissolved oxygen levels under biological conditions provide critical metabolic information about the growing cells as well as the state of the tissue culture within the tissue scaffold. This work focused on the effect of the scaffold morphology on the oxygen sensing response time. It was found that electrospun scaffolds had a faster oxygen-sensing response time than their bulk film counterparts. Tris-(4,7-diphenyl-1,10-phenanthroline) ruthenium (II) dichloride doped electrospun fiber mats of polycaprolactone (PCL) were found to be the most responsive to the presence of oxygen, followed by polyethylene (PEO) glycol mats. Systems containing poly vinyl alcohol were found to be the least responsive. This would suggest that, out of all the polymers tested, PCL and PEO are the most suitable biomaterials for oxygen-sensing applications. - Highlights: • Ru(DPP){sub 3}Cl{sub 2} was blended into common biocompatible polymers such as PEO, PCL, and PVA. • Oxygen sensing was more responsive when polymers were electrospun compared to bulk. • Electrospun PEO and PCL with Ru(dpp){sub 3}Cl{sub 2} showed similar oxygen sensing responses. • PVA showed a slight improvement in oxygen sensing rate when electrospun.

  4. Few-layer and symmetry-breaking effects on the electrical properties of ordered CF3Cl phases on graphene

    Science.gov (United States)

    Morales-Cifuentes, Josue; Wang, Yilin; Reutt-Robey, Janice; Einstein, T. L.

    2014-03-01

    An effective pseudopotential mechanism for breaking the inherent sub-lattice symmetry of graphene has been studied using DFT calculations on hexagonal boron nitride. Electrical detection of CF3Cl phase transitions on graphene shows the existence of a commensurate ordered phase in which this can be tested. We study the electronic properties of this phase using VASP ver 5.3.3, with ab initio van der Waals density functionals (vdW-DF1 and vdW-DF2). Consistent with a physisorbed phase, binding energies and charge transfer per CF3Cl molecule are calculated to be on the order of 280meV and 0.01e, respectively. By exploring different coverages and orientations of this ordered phase we are able to open a band gap in some configurations; said gap is in the range of 8 to 80meV depending on the strength of the effective pseudopotential. Furthermore, we calculate the screening of these effects in bi-layer and tri-layer graphene. Work supported by NSF-MRSEC at UMD, grant DMR 05-20471 and NSF-CHE 13-05892.

  5. Heat and Mass Transfer during Solid-Liquid Phase Transition of n-Alkanes in the C{sub 16} to C{sub 19} Range

    Energy Technology Data Exchange (ETDEWEB)

    Holmen, Rune

    2002-07-01

    The main goal of this project has been to study heat and mass transfer during solid-liquid phase transition of n-alkanes in the in the C{sub 16} to C{sub 19} range. Phase transitions of both mixtures and pure components have been investigated. All experiments and simulations have been performed without any convection. Thermal conductivities have been determined at the melting point for solid and liquid unbranched alkanes ranging from C{sub 16} to C{sub 19}. An assessment of the error of the method has been performed. The measurements of solid conductivities are in accordance with measurements reported previously and confirm the applicability of the method. Liquid conductivities are higher than extrapolated values from the literature. The enhanced conductivity is believed to be caused by structural changes close to the melting point which is not taken into account when extrapolating values from the literature. Experiments have been performed for the purpose of investigating the freezing of mixtures of n-alkanes in the C{sub 16}-C{sub 19} range. The positions of the solid-liquid interfaces have been measured as freezing occurred. Calculations of the ratio of liquid and solid conductivities show that the solid structure of mixtures of the investigated n-alkanes is predominantly in a rotator structure at the temperatures investigated. There are indications of a transformation into an orthorhombic structure at lower temperatures. The temperatures on the solid-liquid interface have been measured, and compared with calculated values from chapter 4. The temperature of the interface is represented better by the measured interfacial temperatures than by the calculated interfacial temperatures. The experimental results indicate that the diffusion of heat is the limiting mechanism of phase transition. This result in a homogeneous liquid composition. A numerical model has been developed in order to simulate the experimental freezing of mixtures. The model represents the results

  6. VERTICAL DISTRIBUTION OF C{sub 3}-HYDROCARBONS IN THE STRATOSPHERE OF TITAN

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cheng; Gao, Peter; Yung, Yuk [Division of Geological and Planetary Science, California Institute of Technology, Pasadena, CA 91125 (United States); Zhang, Xi [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

    2015-04-20

    Motivated by the recent detection of propene (C{sub 3}H{sub 6}) in the atmosphere of Titan, we use a one-dimensional Titan photochemical model with an updated eddy diffusion profile to systematically study the vertical profiles of the stable species in the C{sub 3}-hydrocarbon family. We find that the stratospheric volume mixing ratio of propene (C{sub 3}H{sub 6}) peaks at 150 km with a value of 5 × 10{sup −9}, which is in good agreement with recent observations by the Composite Infrared Spectrometer on the Cassini spacecraft. Another important species that is currently missing from the hydrocarbon family in Titan's stratosphere is allene (CH{sub 2}CCH{sub 2}), an isomer of methylacetylene (CH{sub 3}C{sub 2}H). We predict that its mixing ratio in the stratosphere is about 10{sup −9}, which is on the margin of the detection limit. CH{sub 2}CCH{sub 2} and CH{sub 3}C{sub 2}H equilibrate at a constant ratio in the stratosphere by hydrogen-exchanging reactions. Thus, by precisely measuring the ratio of CH{sub 2}CCH{sub 2} to CH{sub 3}C{sub 2}H, the abundance of atomic hydrogen in the atmosphere can be inferred. No direct yield for the production of cyclopropane (c-C{sub 3}H{sub 6}) is available. From the discharge experiments of Navarro-González and Ramírez, the abundance of cyclopropane is estimated to be 100 times less than that of C{sub 3}H{sub 6}.

  7. C{sub 3} as the dominant carbon cluster in high pressure discharges in graphite hollow cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Janjua, Sohail Ahmad; Ahmad, Mashkoor; Khan, Sabih-ud-Din; Khalid, Rahila; Aleem, Abid; Ahmad, Shoaib [Carbon Based Nanotechnology and Accelerator Laboratory, PINSTECH, PO Box Nilore, Islamabad (Pakistan)

    2007-03-07

    Results are presented that have been obtained while operating the graphite hollow cathode duoplasmatron ion source in dual mode under constant discharge current. This dual mode operation enabled us to obtain the mass and emission spectra simultaneously. In mass spectra C{sub 3} is the main feature but C{sub 4} and C{sub 5} are also prominent, whereas in emission spectra C{sub 2} is also there and its presence shows that it is in an excited state rather than in an ionic state. These facts provide evidence that C{sub 3} is produced due to the regeneration of a soot forming sequence and leave it in ionic state. C{sub 3} is a stable molecule and the only dominant species among the carbon clusters that survives in a regenerative sooting environment at high-pressure discharges.

  8. Production of levulinic acid, furfural, and gamma valerolactone from C.sub.5 and C.sub.6 carbohydrates in mono- and biphasic systems using gamma-valerolactone as a solvent

    Science.gov (United States)

    Dumesic, James A.; Alonso, David Martin; Gurbuz, Elif I.; Wettstein, Stephanie G.

    2013-03-19

    A method to make levulinic acid (LA), furfural, or gamma-valerolactone (GVL). React cellulose (and/or other C.sub.6 carbohydrates) or xylose (and/or other C.sub.5 carbohydrates) or combinations thereof in a monophasic reaction medium comprising GVL and an acid; or (ii) a biphasic reaction system comprising an organic layer comprising GVL, and a substantially immiscible aqueous layer. At least a portion of the cellulose (and/or other C.sub.6 carbohydrates), if present, is converted to LA and at least a portion of the xylose (and/or other C.sub.5 carbohydrates), if present, is converted into furfural.

  9. EELS, XPS and IR study of C{sub 60}.2S{sub 8} compound

    Energy Technology Data Exchange (ETDEWEB)

    Shul`ga, Yu.M. [Inst. of Chemical Physics, RAS, Chernogolovka (Russian Federation); Rubtsov, V.I. [Inst. of Chemical Physics, RAS, Chernogolovka (Russian Federation); Vasilets, V.N. [Inst. of Energetic Problems of Chemical Physics, RAS, Chernogolovka (Russian Federation); Lobach, A.S. [Inst. of Chemical Physics, RAS, Chernogolovka (Russian Federation); Spitsyna, N.G. [Inst. of Chemical Physics, RAS, Chernogolovka (Russian Federation); Yagubskii, E.B. [Inst. of Chemical Physics, RAS, Chernogolovka (Russian Federation)

    1995-03-15

    Results from electron energy loss, X-ray photoelectron, and infrared spectroscopies are ptesented for the C{sub 60}.2S{sub 8} compound. As one goes from C{sub 60} to C{sub 60}.2S{sub 8}, binding energy decreases by 0.5 eV, and ({sigma}+{pi}) plasmon energy decreases by 1.2 eV. Arguments for charge redistribution are performed. (orig.)

  10. The role of carbonic anhydrase in C>4 photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Studer, Anthony [Life Sciences Research Foundation, Baltimore, MD (United States)

    2015-10-01

    Current pressures on the global food supply have accelerated the urgency for a second green revolution using novel and sustainable approaches to increase crop yield and efficiency. This proposal outlines experiments to address fundamental questions regarding the biology of C>4 photosynthesis, the method of carbon fixation utilized by the most productive food, feed and bioenergy crops. Carbonic anhydrase (CA) has been implicated in multiple cellular functions including nitrogen metabolism, water use efficiency, and photosynthesis. CA catalyzes the first dedicated step in C>4 photosynthesis, the hydration of CO2 into bicarbonate, and is potentially rate limiting in C>4 grasses. Using insertional mutagenesis, we have generated CA mutants in maize, and propose the characterization of these mutants using phenotypic, physiological, and transcriptomic profiling to assay the plant’s response to altered CA activity. In addition, florescent protein tagging experiments will be employed to study the subcellular localization of CA paralogs, providing critical data for modeling carbon fixation in C>4 plants. Finally, I propose parallel experiments in Setaria viridis to explore its relevance as model C>4 grass. Using a multifaceted approach, this proposal addresses important questions in basic biology, as well as the need for translation research in response to looming global food challenges.

  11. Tunneling magnetoresistance of C{sub 2}H{sub 2} molecules sandwiched between Co clusters

    Energy Technology Data Exchange (ETDEWEB)

    Zare-Kolsaraki, H. E-mail: kolsarak@ph2.uni-koeln.de; Micklitz, H

    2004-09-01

    The tunneling magnetoresistance (TMR) of samples containing well-defined Co clusters ({approx}4.5 nm mean diameter) embedded in C{sub 2}H{sub 2} matrices essentially is independent of Co-cluster volume fraction v{sub Co} and reveals a value of about 26% at T=2 K. This result is in contrast to that obtained for Co clusters embedded in C{sub 2}H{sub 4} matrices (Phys. Rev. B 67 (2003) 094433). In the latter system the TMR strongly decreased with increasing v{sub Co} indicating different possible orientation of the C{sub 2}H{sub 4} molecule sandwiched between the Co clusters. We, therefore, conclude that the C{sub 2}H{sub 2} molecules are sandwiched in a rather well-defined orientation between the Co clusters. They probably form double layers of C{sub 2}H{sub 2} molecules with the C-C bond axis parallel to the Co cluster surface.

  12. Tribomechanical behavior of B{sub 4}C{sub p} reinforced Al 359 composites

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Deivasigamani; Rathanasamy, Rajasekar [Kongu Engineering College, Tamil Nadu (India). Dept. of Mechanical Engineering; Subramanian, Mohan Kumar; Kaliyannan, Gobinath Velu [PAAVAI Engineering College, Tamil Nadu (India). Dept. of Mechatronics Engineering; Palaniappan, Sathish Kumar [Indian Institute of Technology, Kharagpur, West Bengal (India); Durairaj, Jayanth

    2017-03-01

    n the present investigation, the influence of B{sub 4}C{sub p} particles on the mechanical and tribological behavior of Al 359 composites has been studied. B{sub 4}C{sub p} particle reinforced Al 359 composite samples were prepared by stir casting process. Hardness, tensile strength and wear behavior of the composites were studied and compared with a control specimen. Hardness of B{sub 4}C{sub p} particles reinforced Al 359 matrix increases compared to base matrix due to the presence of the ceramic phase. Coefficient of friction considerably increases with up to 20 wt.-% addition of B{sub 4}C{sub p} in base matrix. Specimens were subjected to wear tests under different load conditions and the following five different wear mechanisms such as wear groove, abrasion, delamination, oxidation and plastic deformation were evaluated. The abrasion results prove the increase in wear resistance of B{sub 4}C{sub p} reinforced composites compared to a control specimen.

  13. Room temperature inductively coupled plasma etching of InAs/InSb in BCl 3/Cl 2/Ar

    KAUST Repository

    Sun, Jian

    2012-10-01

    Inductively coupled plasma (ICP) etching of InAs and InSb at room temperature has been investigated using BCl 3/Cl 2/Ar plasma. Specifically, the etch rate and post-etching surface morphology were investigated as functions of the gas composition, ICP power, process pressure, and RF chuck power. An optimized process has been developed, yielding anisotropic etching and very smooth surfaces with roughnesses of 0.25 nm for InAs, and 0.57 nm for InSb, which is comparable with the surface of epi-ready polished wafers. The process provides moderate etching rates of 820 /min for InAs and 2800 /min for InSb, and the micro-masking effect is largely avoided. © 2012 Elsevier B.V. All rights reserved.

  14. Infrared/Terahertz double resonance spectroscopy of CH3F and CH3Cl at atmospheric pressure

    CERN Document Server

    Phillips, Dane J; De Lucia, Frank C; Everitt, Henry O

    2012-01-01

    A new method for highly selective remote sensing of atmospheric trace polar molecular gases is described. Based on infrared/terahertz double resonance spectroscopic techniques, the molecule- specific coincidence between the lines of a CO2 laser and rotational-vibrational molecular absorption transitions provide two dimensions of recognition specificity: infrared coincidence frequency and the corresponding terahertz frequency whose absorption strength is modulated by the laser. Atmospheric pressure broadening expands the molecular recognition "specificity matrix" by simultaneously relaxing the infrared coincidence requirement and strengthening the corresponding terahertz signature. Representative double resonance spectra are calculated for prototypical molecules CH3F and CH3Cl and their principal isotopomers, from which a heuristic model is developed to estimate the specificity matrix and double resonance signature strength for any polar molecule.

  15. CH3Cl, CH2Cl2, CHCl3, and CCl4: Infrared spectra, radiative efficiencies, and global warming potentials

    Science.gov (United States)

    Wallington, Timothy J.; Pivesso, Bruno Pasquini; Lira, Alane Moura; Anderson, James E.; Nielsen, Claus Jørgen; Andersen, Niels Højmark; Hodnebrog, Øivind

    2016-05-01

    Infrared spectra for the title compounds were measured experimentally in 700 Torr of air at 295 K and systematically modeled in B3LYP, M06-2X and MP2 calculations employing various basis sets. Calibrated infrared spectra over the wavenumber range 600-3500 cm-1 are reported and combined with literature data to provide spectra for use in experimental studies and radiative transfer calculations. Integrated absorption cross sections are (units of cm-1 molecule-1): CH3Cl, 660-780 cm-1, (3.89±0.19)×10-18; CH2Cl2, 650-800 cm-1, (2.16±0.11)×10-17; CHCl3, 720-810 cm-1, (4.08±0.20)×10-17; and CCl4, 730-825 cm-1, (6.30±0.31)×10-17. CH3Cl, CH2Cl2, CHCl3, and CCl4 have radiative efficiencies of 0.004, 0.028, 0.070, and 0.174 W m-2 ppb-1 and global warming potentials (100 year horizon) of 5, 8, 15, and 1775, respectively. Quantum chemistry calculations generally predict larger band intensities than the experimental values. The best agreement with experiments is obtained in MP2(Full) calculations employing basis sets of at least triple-zeta quality augmented by diffuse functions. The B3LYP functional is found ill-suited for calculating vibrational frequencies and infrared intensities of halocarbons.

  16. Dysprosium carbide iodides Dy{sub 10}(C{sub 2}){sub 2}I{sub 18}, Dy{sub 4}(C{sub 2})I{sub 6} and Dy{sub 12}(C{sub 2}){sub 3}I{sub 17}; Dysprosiumcarbidiodide Dy{sub 10}(C{sub 2}){sub 2}I{sub 18}, Dy{sub 4}(C{sub 2})I{sub 6} und Dy{sub 12}(C{sub 2}){sub 3}I{sub 17}

    Energy Technology Data Exchange (ETDEWEB)

    Mattausch, H.; Hoch, C.; Simon, A. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2007-02-15

    The title compounds are formed by reaction of DyI{sub 3}, Dy metal and C in stoichiometric amounts in closed Ta ampoules, Dy{sub 10}(C{sub 2}){sub 2}I{sub 18} at 930 C for 7 days, Dy{sub 4}(C{sub 2})I{sub 6} at 950 C for 6 days and Dy{sub 12}(C{sub 2}){sub 3}I{sub 17} at 900 C for 11 days as pure samples according to X-ray powder diffraction. Dy{sub 10}(C{sub 2}){sub 2}I{sub 18} crystallizes in space group P2{sub 1}/c with a = 10.470(2), b = 17.152(3), c = 13.983(3) Aa and {beta} = 121.14(3) , Dy{sub 4}(C{sub 2})I{sub 6} in Pnnm with a = 13.622(3), b = 14.335(3) and c = 8.396(2) Aa, and Dy{sub 12}(C{sub 2}){sub 3}I{sub 17} in C2/c with a = 19.149(4), b = 12.069(2), c = 18.595(4) Aa, and {beta} = 90.54(3) . The crystal structure of Dy{sub 10}(C{sub 2}){sub 2}I{sub 18} is composed of Dy double octahedra centered by (C{sub 2}){sup 6-} groups (ethanide) with the iodide ions above the edges and the corners of the Dy{sub 10}(C{sub 2}){sub 2} units. In Dy{sub 4}(C{sub 2})I{sub 6} the Dy atoms form chains of trans-edge sharing octahedra with embedded (C{sub 2}) groups. In the structure of Dy{sub 12}(C{sub 2}){sub 3}I{sub 17} alternately cis-, trans-edge-condensed Dy{sub 6} octahedra centered by (C{sub 2}) groups occur. The iodine atoms surround the chains like in the M{sub 6}X{sub 12} cluster and interconnect neighboring chains. (orig.)

  17. K3CL METAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is a routine scheduled observation and is the primary observation code used in the United States to satisfy requirements for reporting surface meteorological...

  18. Transport properties of carbide superconductor La{sub 2}C{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. S. [Dept. of Physics, Pohang University of Science and Technology, Pohang (Korea, Republic of); Kremer, R. K. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Korea, Republic of)

    2013-03-15

    We investigate the electrical and thermal transport properties of a sesquicarbide superconductor La{sub 2}C{sub 3}, including electrical resistivity, thermoelectric power, and thermal conductivity. The electrical resistivity exhibits a typical metallic character with a saturation behavior at high temperatures. The thermoelectric power shows a metallic behavior with pronounced phonon-drag effect, comparable with pure metals. The broad peak of the thermal conductivity is observed in the superconducting state, which is rapidly suppressed by magnetic fields. These observations suggest that the electron-phonon scattering is significant in La{sub 2}C{sub 3}, which is relevant with the relatively high-T{sub c} in La{sub 2}C{sub 3} through strong electron-phonon coupling with low frequency phonon modes.

  19. Compensation effects in C{sub 60} doped by ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Trouillas, P.; Ratier, B.; Moliton, A. [LEPOFI, Faculte des Sciences, Limoges (France)

    1995-12-31

    We have studied electrical transport phenomena after ion implantation in sublimed C{sub 60} films. A n type doping exists with 30 KeV potassium ion irradiations and low fluences (D < 10{sup 15} ions/cm{sup 2}). However degradation effects have been noted. So we have tried to discriminate doping and damage effects. Studies about the compensation phenomenum have been performed in order to prove the chemical role of the potassium atoms. An electron transfer from the alkali metal is sure; but a strong competition exists between degradation and doping phenomena. Finally, the intact C{sub 60} molecules are the insulator barriers, K{sub 3}C{sub 60} and isolated carbon atoms are the conductor phase for an heterogeneous media model. (Author).

  20. Microstructural analysis of carbon films obtained from C{sub 60} fullerene ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Huck, H.; Halac, E.B.; Reinoso, M.; Dall' Asen, A.G.; Somoza, A.; Deng, W.; Brusa, R.S.; Karwasz, G.P.; Zecca, A

    2003-04-30

    Carbon films have been produced by accelerating C{sub 60}{sup +} ions on silicon substrates with energies between 100 and 800 eV. Furthermore some samples have been vacuum-annealed at 600 deg. C. The samples have been characterized by Raman and positron annihilation spectroscopies (RS-PAS). The measurements for the as-deposited material show that there is a coexistence of polymerized fullerenes and amorphous-carbon islands and that the structure depends on the energy of the incident ions. At low energies, fullerenes are deposited preserving the molecular identity and some intermolecular covalent bonds begin to insinuate; at higher energies, the amount of these covalent bonds increases and the amorphous islands predominate. After the annealing process, the amorphous phase organizes in graphitic clusters and the unbroken C{sub 60} cages are transformed back to pristine and slightly polymerized C{sub 60}.

  1. A photoemission study of the diamond and the single crystal C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jin

    1994-03-01

    This report studied the elctronic structure of diamond (100) and diamond/metal interface and C{sub 60}, using angle-resolved and core level photoemission. The C(100)-(2X1) surface electronic structure was studied using both core level and angle resolved valence band photoemission spectroscopy. The surface component of the C 1s core level spectrum agrees with theoretical existence of only symmetrical dimers. In the case of metal/diamond interfaces, core level and valence photoelectron spectroscopy and LEED studies WERE MADE OF B and Sb on diamond (100) and (111) surfaces. In the case of single-crystal C{sub 60}, photoemission spectra show sharp molecular features, indicating that the molecular orbitals are relatively undisturbed in solid C{sub 60}.

  2. Investigation of electronic density in C[sub 60] by compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bellin, Ch.; Marangolo, M. (LMCP, Universite Paris VI, Paris Cedex (France)); Moscovici, J. (LPMD, Universite Paris XII, Creteil Cedex (France)); Loupias, G. (LURE, Bat. 209, Universite Paris-Sud, Orsey Cedex (France)); Rabii, S. (Dept. Electrical Engineering, Univ. Pensylvania, Philadelphia (United States)); Erwin, S. (Complex Systems Theory Branch, Naval Research Lab., Washington (United States))

    1997-01-01

    High-resolution measurements of Compton profiles on C[sub 60] as well as K[sub x]C[sub 60] have been carried out using 16 keV photons at LURE (Orsay, France) and at ESRF (Grenoble, France). Theoretical profiles are obtained using the plane wave expansion of wave functions from an ab initio self-consistent field calculation of the energy band structure. The linear combination of atomic orbitals method within local-density-approximation has been employed for the calculation. In all cases, the agreement between theory and experiment is excellent. The C[sub 60] profiles indicate substantially greater delocalization of the ground state charge density, compared to graphite. We have demonstrated, both by experimental and calculation, that the delocalization in C[sub 60] is mainly a molecular effect. (author) 16 refs, 3 figs

  3. Investigation of electronic density in C{sub 60} by compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bellin, Ch.; Marangolo, M. [LMCP, Universite Paris VI, Paris Cedex (France); Moscovici, J. [LPMD, Universite Paris XII, Creteil Cedex (France); Loupias, G. [LURE, Bat. 209, Universite Paris-Sud, Orsey Cedex (France); Rabii, S. [Dept. Electrical Engineering, Univ. Pensylvania, Philadelphia (United States); Erwin, S. [Complex Systems Theory Branch, Naval Research Lab., Washington (United States)

    1997-12-31

    High-resolution measurements of Compton profiles on C{sub 60} as well as K{sub x}C{sub 60} have been carried out using 16 keV photons at LURE (Orsay, France) and at ESRF (Grenoble, France). Theoretical profiles are obtained using the plane wave expansion of wave functions from an ab initio self-consistent field calculation of the energy band structure. The linear combination of atomic orbitals method within local-density-approximation has been employed for the calculation. In all cases, the agreement between theory and experiment is excellent. The C{sub 60} profiles indicate substantially greater delocalization of the ground state charge density, compared to graphite. We have demonstrated, both by experimental and calculation, that the delocalization in C{sub 60} is mainly a molecular effect. (author) 16 refs, 3 figs

  4. Process for separating C/sub 2+/ hydrocarbons from natural gas. Verfahren zur Abtrennung von C/sub 2+/-Kohlenwasserstoffen aus Erdgas

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, H.; Sapper, R.

    1987-03-05

    A process for separating C/sub 2+/ hydrocarbons from natural gas is claimed in which the natural gas is cooled, partially condensed, and separated into a liquid and a gaseous fraction. The liquid fraction is subcooled, expanded in the top region of a rectification column, and mixed with the expanded gaseous fraction. The rectification process produces a product flow containing C/sub 2+/ hydrocarbons, and a residual gas containing mostly lower-boiling constituents. The residual gas is heated up by indirect heat exchange with condensate and then by heat exchange with the gaseous fraction after partial condensation and with the natural gas led into the partial condensation process. The heated residual gas is expanded, producing work, and heated again by heat exchange with the natural gas to be cooled.

  5. Equation of motion coupled cluster methods for electron attachment and ionization potential in fullerenes C{sub 60} and C{sub 70}

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskaran-Nair, Kiran [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70802 (United States); Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Kowalski, Karol, E-mail: karol.kowalski@pnnl.gov [William R. Wiley Environmental Molecular Sciences Laboratory, Battelle, Pacific Northwest National Laboratory, K8-91, P.O.Box 999, Richland, Washington 99352 (United States); Moreno, Juana; Jarrell, Mark [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70802 (United States); Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Shelton, William A. [Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

    2014-08-21

    In both molecular and periodic solid-state systems there is a need for the accurate determination of the ionization potential and the electron affinity for systems ranging from light harvesting polymers and photocatalytic compounds to semiconductors. The development of a Green's function approach based on the coupled cluster (CC) formalism would be a valuable tool for addressing many properties involving many-body interactions along with their associated correlation functions. As a first step in this direction, we have developed an accurate and parallel efficient approach based on the equation of motion-CC technique. To demonstrate the high degree of accuracy and numerical efficiency of our approach we calculate the ionization potential and electron affinity for C{sub 60} and C{sub 70}. Accurate predictions for these molecules are well beyond traditional molecular scale studies. We compare our results with experiments and both quantum Monte Carlo and GW calculations.

  6. [sup 13]C NMR on C[sub 60] single-crystal. RMN du [sup 13]C sur un monocristal de C[sub 60

    Energy Technology Data Exchange (ETDEWEB)

    Kerkoud, R.; Auban-Senzier, P.; Godard, J.; Jerome, D. (Paris-11 Univ., 91 - Orsay (France). Lab. de Physique des Solides); Lambert, J.M.; Bernier, P. (Montpellier-1 Univ., 34 (France))

    1994-01-01

    The authors report a [sup 13]C NMR study performed on a C[sub 60] single crystal (8% enriched in [sup 13]C) grown by sublimation. Molecular motions are tested by spin-lattice relaxation data and spectral shapes below and above the structural transition at T[sub c] = 262 K. The sharpness of this transition and the long relaxation times at low temperature, compared to previous data on powdered samples, confirm the high purity of the crystal.

  7. Occupied and unoccupied orbitals of C{sub 60} and C{sub 70} probed with C 1s emission and absorption

    Energy Technology Data Exchange (ETDEWEB)

    Carlisle, J.A.; Terminello, L.J.; Hudson, E.A. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    The aim of this work is to characterize the orbital structure of the fullerenes, and to pursue its evolution from a cluster to the infinite solid. For obtaining a complete picture of the electronic structure the authors compare a variety of experimental techniques, i.e. photoemission and core level emission for occupied orbitals and inverse photoemission and core level absorption for unoccupied orbitals. Their experimental results focus on optical probes involving the C 1s core level, i.e. absorption via transitions from the C 1s level into unoccupied {pi}* and {sigma}* orbitals and emission involving transitions from occupied orbitals into a C 1s hole. Due to the simplicity of the C 1s level there exist clear selection rules. For example, only transitions to and from orbitals with p-character are dipole-allowed. These results on the p-projected density of states are compared with inverse photoemission and photoemission results, where the selection rules are less definitive. In addition, a first-principles quasiparticle calculation of the density of states is used to assign the orbital features. The spectra from C{sub 60} and C{sub 70} are still far from their infinite analog, i.e., graphite, which is also measured with the same techniques. In order to determine the effect of electron transfer onto C{sub 60}, as in superconducting alkali fullerides, the authors are studying resonant emission of C{sub 60}. An electron is placed in the lowest unoccupied molecular orbital (LUMO) by optical absorption from the C 1s level and the C 1s emission detected in the presence of this spectator electron.

  8. Nanocrystalline gold in Au-doped thin C{sub 60} films

    Energy Technology Data Exchange (ETDEWEB)

    Devenyi, A.; Manaila, R.; Belu-Marian, A.; Macovei, D.; Manciu, M.; Popescu, E.M.; Tanase, M.; Fratiloiu, D.; Mihai, N.D. [Nat. Inst. for Phys. of Mater., Bucharest (Romania); Barna, P.B.; Labar, J.; Safran, G.; Kovacs, A. [Research Institute for Technical Physics, Hungarian Academy of Sciences, P.O. Box 76, H-1325, Budapest (Hungary); Braun, T. [Institute of Inorganic and Analytic Chemistry, L. Eoetvoes University, P.O. Box 123, 1443, Budapest (Hungary)

    1998-12-14

    Thin Au-C{sub 60} films with global composition Au{sub x}C{sub 100-x} (x between 0.35 and 4.50 at.%) were prepared by vacuum co-deposition and investigated by X-ray diffraction, EDS, XTEM and electrical transport. Evidence indicated the formation of distorted nanocrystalline Au, presumably stabilized by interface electron transfer into C{sub 60} LUMO. Electrical results are interpreted in the frame of the dominant current model, with a continuous density of localized states induced by Au in the C{sub 60} gap. There is also evidence for variable range hopping at low temperatures. (orig.) 20 refs.

  9. Electromagnetic wave propagation in a random distribution of C{sub 60} molecules

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah, Iran and Department of Nano Sciences, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of)

    2014-10-15

    Propagation of electromagnetic waves in a random distribution of C{sub 60} molecules are investigated, within the framework of the classical electrodynamics. Electronic excitations over the each C{sub 60} molecule surface are modeled by a spherical layer of electron gas represented by two interacting fluids, which takes into account the different nature of the π and σ electrons. It is found that the present medium supports four modes of electromagnetic waves, where they can be divided into two groups: one group with shorter wavelength than the light waves of the same frequency and the other with longer wavelength than the free-space radiation.

  10. Rubidium isotope effect in superconducting Rb[sub 3]C[sub 60

    Energy Technology Data Exchange (ETDEWEB)

    Burk, B.; Crespi, V.H.; Zettl, A.; Cohen, M.L. (Department of Physics, University of California at Berkeley, Berkeley, California 94720 (United States) Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

    1994-06-06

    We have measured the resistive supercondeucting transition temperature in C[sub 60] single crystals intercalated with isotopically pure [sup 87]Rb and [sup 85]Rb and with natural abundance rubidium. We obtain a rubidium isotope effect exponent of [alpha][sub Rb]=[minus]0.028[plus minus]0.036, a result which implies that the Rb-C[sub 60] optic phonons play at most a minor role in the pairing mechanism of Rb[sub 3]C[sub 60].

  11. Interstellar C/sub 3/N: Detection in Taurus dark clouds

    Energy Technology Data Exchange (ETDEWEB)

    Friberg, P.; Hjalmarson, A.; Irvine, W.M.; Guelin, M.

    1980-10-15

    We report the first detection of the radical C/sub 3/N in interstellar sources, at the centers of the two dark clouds TMC 1 and TMC 2. The very small line widths observed for this low-order transition (N=3..-->..2) allow a partial resolution of the hyperfine structure and a tentative estimate of this radical's hyperfine constants. The C/sub 3/N/HC/sub 3/N abundance ratio observed in the two clouds is similar to that in IRC+10216, but much larger than the upper limit derived for Orion A and Sagittarius B2.

  12. Optical, structural and electrical properties of polyaniline systems doped with C{sub 60} and small gap C{sub 60} fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Politakos, Nikolaos; Zalakain, Iñaki; Fernandez d' Arlas, Borja; Eceiza, Arantxa; Kortaberria, Galder, E-mail: galder.cortaberria@ehu.es

    2013-10-01

    In this work two systems consisting on polyaniline (Pani) doped with simple and small gap C{sub 60} fullerenes have been prepared and characterized. Composites with different doping amounts of 1,2,4 and 8 wt% have been analyzed in order to evaluate their structure together with their optical and electrical properties and the effect of fullerene type and amount on them. The shift and change of shape in Fourier transform infrared spectroscopy (FTIR) bands and solid {sup 13}C NMR spectroscopy signals showed the presence of interactions between matrix and fullerenes by electron density transfer among them. Optical properties have also been analyzed in terms of ultraviolet (UV) spectroscopy. The blue shift of several bands confirmed the charge transfer. Obtained structures have been analyzed by optical microscopy (OM) showing the different way in which both types of fullerenes have been incorporated into the polymer chains. Finally, conductivity has been measured by the four probe technique, relating obtained values with the structure of the composite and the different degree of crystallinity of simple and small gap fullerenes. - Highlights: • Use of small gap fullerenes as doping agent with polyaniline (Pani). • Electrical properties comparison between simple C{sub 60} and small gap fullerenes systems with polyaniline. • Different conductive behavior for small gap fullerenes and simple C{sub 60} depending on their size. • Study of optical and structural properties of different Pani/fullerenes composite systems. • Enhanced electrical properties for both systems in respect to the neat polyaniline (Pani)

  13. The ternary thorium aluminium carbides Th{sub 2}Al{sub 2}C{sub 3} and ThAl{sub 4}C{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Gesing, T.M. [Muenster Univ. (Germany). Anorganisch-Chemisches Inst.; Jeitschko, W. [Muenster Univ. (Germany). Anorganisch-Chemisches Inst.

    1996-07-01

    The title compounds were prepared by arc-melting cold-pressed pellets of the elemental components with subsequent annealing at 900 C. Th{sub 2}Al{sub 2}C{sub 3} crystallizes orthorhombic: Pnnm, a=540.6(1) pm, b=1155.6(2) pm, c=352.01(6) pm, Z=2. The structure was determined from powder diffractometer data using the Rietveld method: R{sub F}=0.039 for 42 structure factors and six variable positional parameters. The positions of the metal atoms correspond to those of the InS-type structure. The two different carbon atoms are in octahedral coordination formed by four thorium and two aluminium atoms. The hydrolysis of ThAl{sub 4}C{sub 4} with diluted hydrochloric acid resulted in 74 wt.% methane, 12 wt.% ethane and ethylene and 14 wt.% saturated and unsaturated higher hydrocarbons. Nevertheless, the crystal structure determination from single-crystal X-ray data showed that there are only isolated carbon atoms in the solid: I4/m, a=823.1(1) pm, c=332.73(6) pm, Z=2, R=0.032 for 13 variable parameters and 372 structure factors. It is isotypic with UCr{sub 4}C{sub 4}. The carbon atoms are octahedrally coordinated by two thorium and four aluminium atoms. (orig.)

  14. Effects of C{sub 60} nanoparticle exposure on earthworms (Lumbricus rubellus) and implications for population dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Ploeg, M.J.C. van der, E-mail: merel.vanderploeg@wur.n [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands); Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE, Wageningen (Netherlands); Baveco, J.M.; Hout, A. van der [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands); Bakker, R. [RIKILT, Wageningen UR, Akkermaalsbos 2, 6708 WB, Wageningen (Netherlands); Rietjens, I.M.C.M. [Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE, Wageningen (Netherlands); Brink, N.W. van den [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands)

    2011-01-15

    Effects of C{sub 60} nanoparticles (nominal concentrations 0, 15.4 and 154 mg/kg soil) on mortality, growth and reproduction of Lumbricus rubellus earthworms were assessed. C{sub 60} exposure had a significant effect on cocoon production, juvenile growth rate and mortality. These endpoints were used to model effects on the population level. This demonstrated reduced population growth rate with increasing C{sub 60} concentrations. Furthermore, a shift in stage structure was shown for C{sub 60} exposed populations, i.e. a larger proportion of juveniles. This result implies that the lower juvenile growth rate due to exposure to C{sub 60} resulted in a larger proportion of juveniles, despite increased mortality among juveniles. Overall, this study indicates that C{sub 60} exposure may seriously affect earthworm populations. Furthermore, it was demonstrated that juveniles were more sensitive to C{sub 60} exposure than adults. - C{sub 60} nanoparticle exposure can affect Lumbricus rubellus populations.

  15. Formation of clusters composed of C{sub 60} molecules via self-assembly in critical fluids

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Takahiro [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Ishii, Koji [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Kurosu, Shunji [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Whitby, Raymond [School of Pharmacy and Biomolecular Sciences, University of Brighton, Cockroft Building, Lewes Road, Brighton BN2 4GJ (United Kingdom); Maekawa, Toru [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan)

    2007-04-11

    Fullerenes are promising candidates for intelligent, functional nanomaterials because of their unique mechanical, electronic and chemical properties. However, it is necessary to invent some efficient but relatively simple methods of producing structures composed of fullerenes for the development of nanomechatronic, nanoelectronic and biochemical devices and sensors. In this paper, we show that various structures such as straight fibres, networks formed by fibres, wide sheets and helical structures, which are composed of C{sub 60} molecules, are created by placing C{sub 60}-crystals in critical ethane, carbon dioxide and xenon even though C{sub 60} molecules do not dissolve or disperse in the above fluids. It is supposed, judging by the intermolecular potentials between C{sub 60} and C{sub 60}, between C{sub 60} and ethane, and between ethane and ethane, that C{sub 60}-clusters grow with the assistance of solvent molecules, which are trapped between C{sub 60} molecules under critical conditions. This room-temperature self-assembly cluster growth process in critical fluids may open up a new methodology of forming structures built up with fullerenes without the need for any ultra-fine processing technologies.

  16. Reducing HAuCl{sub 4} by the C{sub 60} dianion: C{sub 60}-directed self-assembly of gold nanoparticles into novel fullerene bound gold nanoassemblies

    Energy Technology Data Exchange (ETDEWEB)

    Liu Wei; Gao Xiang [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China)], E-mail: xgao@ciac.jl.cn

    2008-10-08

    The C{sub 60} dianion is used to reduce tetrachloroauric acid (HAuCl{sub 4}) for the first time; three-dimensional C{sub 60} bound gold (Au-C{sub 60}) nanoclusters are obtained from C{sub 60}-directed self-assembly of gold nanoparticles due to the strong affinities of Au-C{sub 60} and C{sub 60}-C{sub 60}. The process was monitored in situ by UV-vis-NIR spectroscopy. The resulting Au-C{sub 60} nanoclusters were characterized using transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy-dispersive spectroscopy (EDS), x-ray powder diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and FT-IR and Raman spectroscopies. TEM demonstrates the formation of 3D nanonetwork aggregates, which are composed of discrete gold nanocores covered with a C{sub 60} monolayer. The SAED and XRD patterns indicate that the gold nanocores inside the capped C{sub 60} molecules belong to the face-centred cubic crystal structure, while the C{sub 60} molecules are amorphous. The EDS and XPS measurements validate that the Au-C{sub 60} nanoclusters contain only Au and C elements and Au{sup 3+} is reduced to Au{sup 0}. FT-IR spectroscopy shows the chemiadsorption of C{sub 60} to the gold nanocores, while Raman spectroscopy demonstrates the electron transfer from the gold nanocores to the chemiadsorbed C{sub 60} molecules. Au-C{sub 60} nanoclusters embedded in tetraoctyl-n-ammonium bromide (TOAB) on glassy carbon electrodes (GCEs) have been fabricated and have shown stable and well-defined electrochemical responses in aqueous solution.

  17. Superchiral Pd3 L6 Coordination Complex and Its Reversible Structural Conversion into Pd3 L3 Cl6 Metallocycles.

    Science.gov (United States)

    Jurček, Ondřej; Bonakdarzadeh, Pia; Kalenius, Elina; Linnanto, Juha Matti; Groessl, Michael; Knochenmuss, Richard; Ihalainen, Janne A; Rissanen, Kari

    2015-12-14

    Large, non-symmetrical, inherently chiral bispyridyl ligand L derived from natural ursodeoxycholic bile acid was used for square-planar coordination of tetravalent Pd(II) , yielding the cationic single enantiomer of superchiral coordination complex 1 Pd3 L6 containing 60 well-defined chiral centers in its flower-like structure. Complex 1 can readily be transformed by addition of chloride into a smaller enantiomerically pure cyclic trimer 2 Pd3 L3 Cl6 containing 30 chiral centers. This transformation is reversible and can be restored by the addition of silver cations. Furthermore, a mixture of two constitutional isomers of trimer, 2 and 2', and dimer, 3 and 3', can be obtained directly from L by its coordination to trans- or cis-N-pyridyl-coordinating Pd(II) . These intriguing, water-resistant, stable supramolecular assemblies have been thoroughly described by (1) H DOSY NMR, mass spectrometry, circular dichroism, molecular modelling, and drift tube ion-mobility mass spectrometry.

  18. Dynamic Reaction Mechanisms of ClO(-) with CH3Cl: Comparison Between Direct Dynamics Trajectory Simulations and Experiment.

    Science.gov (United States)

    Yu, Feng

    2016-03-24

    We have investigated the dynamic reaction mechanisms of *ClO¯ with CH3Cl (the asterisk is utilized to label a different Cl atom). Ab initio molecular dynamics simulations at the MP2/6-31+G(d,p) level of theory have been employed to compute the dynamic trajectories. On the basis of our simulations, the dynamic reaction pathways for the bimolecular nucleophilic substitution (SN2) reaction channel and SN2-induced elimination reaction channel are clearly illustrated. For the SN2 reaction channel, some trajectories directly dissociate to the final products of CH3O*Cl and Cl¯, whereas the others involve the dynamic Cl¯···CH3O*Cl intermediate complex. As to the SN2-induced elimination reaction channel, the trajectories lead to the final products of CH2O, HCl, and *Cl¯ through the dynamic Cl¯···CH3O*Cl intermediate complex. More significantly, the product branching ratios of Cl¯ and *Cl¯ predicted by our simulations are basically consistent with previous experimental results (Villano et al. J. Am. Chem. Soc. 2009, 131, 8227-8233).

  19. A new, double-inversion mechanism of the F(-) + CH3Cl SN2 reaction in aqueous solution.

    Science.gov (United States)

    Liu, Peng; Wang, Dunyou; Xu, Yulong

    2016-11-23

    Atomic-level, bimolecular nucleophilic substitution reaction mechanisms have been studied mostly in the gas phase, but the gas-phase results cannot be expected to reliably describe condensed-phase chemistry. As a novel, double-inversion mechanism has just been found for the F(-) + CH3Cl SN2 reaction in the gas phase [Nat. Commun., 2015, 6, 5972], here, using multi-level quantum mechanics methods combined with the molecular mechanics method, we discovered a new, double-inversion mechanism for this reaction in aqueous solution. However, the structures of the stationary points along the reaction path show significant differences from those in the gas phase due to the strong influence of solvent and solute interactions, especially due to the hydrogen bonds formed between the solute and the solvent. More importantly, the relationship between the two double-inversion transition states is not clear in the gas phase, but, here we revealed a novel intermediate complex serving as a "connecting link" between the two transition states of the abstraction-induced inversion and the Walden-inversion mechanisms. A detailed reaction path was constructed to show the atomic-level evolution of this novel double reaction mechanism in aqueous solution. The potentials of mean force were calculated and the obtained Walden-inversion barrier height agrees well with the available experimental value.

  20. Investigation of the CH3Cl + CN(-) reaction in water: Multilevel quantum mechanics/molecular mechanics study.

    Science.gov (United States)

    Xu, Yulong; Zhang, Jingxue; Wang, Dunyou

    2015-06-28

    The CH3Cl + CN(-) reaction in water was studied using a multilevel quantum mechanics/molecular mechanics (MM) method with the multilevels, electrostatic potential, density functional theory (DFT) and coupled-cluster single double triple (CCSD(T)), for the solute region. The detailed, back-side attack SN2 reaction mechanism was mapped along the reaction pathway. The potentials of mean force were calculated under both the DFT and CCSD(T) levels for the reaction region. The CCSD(T)/MM level of theory presents a free energy activation barrier height at 20.3 kcal/mol, which agrees very well with the experiment value at 21.6 kcal/mol. The results show that the aqueous solution has a dominant role in shaping the potential of mean force. The solvation effect and the polarization effect together increase the activation barrier height by ∼11.4 kcal/mol: the solvation effect plays a major role by providing about 75% of the contribution, while polarization effect only contributes 25% to the activation barrier height. Our calculated potential of mean force under the CCSD(T)/MM also has a good agreement with the one estimated using data from previous gas-phase studies.

  1. Molecular depth profiling in ice matrices using C{sub 60} projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Wucher, A.; Sun, S.; Szakal, C.; Winograd, N

    2004-06-15

    The prospects of molecular sputter depth profiling using C{sub 60}{sup +} projectiles were investigated on thick ice layers prepared by freezing aqueous solutions of histamine onto a metal substrate. The samples were analyzed in a ToF-SIMS spectrometer equipped with a liquid metal Ga{sup +} ion source and a newly developed fullerene ion source. The C{sub 60}{sup +} beam was used to erode the surface, while static ToF-SIMS spectra were taken with both ion beams alternatively between sputtering cycles. We find that the signals both related to the ice matrix and to the histamine are about two orders of magnitude higher under 20-keV C{sub 60} than under 15-keV Ga bombardment. Histamine related molecular signals are found to increase drastically if the freshly introduced surface is pre-sputtered with C{sub 60} ions, until at a total ion fluence of about 10{sup 13} cm{sup -2} the spectra are completely dominated by the molecular ion and characteristic fragments of histamine. At larger fluence, the signal is found to decrease with a disappearance cross section of approximately 10{sup -14} cm{sup 2}, until at total fluences of about 10{sup 14} cm{sup -2} a steady state with stable molecular signals is reached. In contrast, no appreciable molecular signal could be observed if Ga{sup +} ions were used to erode the surface.

  2. CSUB CREST Research on Climate Change and the San Joaquin Valley, CA

    Science.gov (United States)

    Krugh, W. C.; Negrini, R. M.; Baron, D.; Gillespie, J.; Horton, R. A.; Montoya, E.; Cruz-Boone, C.; Andrews, G. D.; Guo, J.

    2015-12-01

    As part of the NSF-supported Centers for Excellence in Science and Technology (CREST), student and faculty researchers at California State University, Bakersfield (CSUB) have been investigating the regional impacts of climate change as well as evaluating the potential of local contributions to its abatement. Highlights of this research include; 1) the development of a high-resolution climate record from Tulare Lake sediments that spans the past 20,000 years, 2) the quantitative analysis and prediction of climate change impacts on Sierra Nevada snowpack, 3) the detailed subsurface characterization of San Joaquin Valley oilfields targeted for CO2 sequestration, and 4) the evaluation of proposed host rock suitability under simulated CO2 injection conditions. To date, CSUB CREST supported research has resulted in 26 contributions to peer-reviewed journals (currently published or in-review). A primary goal of CSUB CREST is to improve the recruitment, retention, and success of students from the local community, the majority of whom are from backgrounds under-represented in STEM disciplines. More than 28 students have been directly involved in the basic and applied research projects supported by this program. The majority of these students have received, or are on track to receive, an M.S. degree and have ultimately gained employment in a STEM field or been accepted into a Ph.D. program. This presentation, and others in this session, will focus on the accomplishments, challenges, and strategies for success gleaned from CSUB CREST Phase 1.

  3. Low extraction recovery of fullerene from carbonaceous geological materials spiked with C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Jehlicka, J.; Frank, O.; Hamplova, V.; Pokorna, Z.; Juha, L.; Bohacek, Z.; Weishauptova, Z. [Charles University, Prague (Czech Republic). Inst. for Geochemical Mineral & Mineral Resources

    2005-08-01

    Soxhlet extraction, sonication, and ultracritical extraction were tested with respect to their capacity to extract fullerenes from natural carbonaceous materials. Toluene solutions with various contents of synthetic C{sub 60} were added to powdered graphite, shungite, bituminous coal, and quartz, with final C{sub 60} concentration 0.1-100 ppm. The C{sub 60}-doped materials were leached in three kinds of extraction apparatus. High-performance liquid chromatography (HPLC) was used to analyse the fullerene content in the obtained toluene extracts. Surprisingly low yields of the C{sub 60} extraction (most of them well below 5%) were determined for all the carbonaceous matrices and all the extraction techniques employed in the fullerene isolation. This finding has serious consequences for better understanding of the reported fullerene occurrence in the geological environment, because a greatly limited extraction yield can be responsible for some negative results of fullerene analyses in various geological samples. Both fullerene stability in solvents and fullerene interaction with the surfaces of geological carbonaceous matrices are discussed to explain the obtained results.

  4. REVERSIBLE HYDROGEN STORAGE IN A LiBH{sub 4}-C{sub 60} NANOCOMPOSITE

    Energy Technology Data Exchange (ETDEWEB)

    Teprovich, J.; Zidan, R.; Peters, B.; Wheeler, J.

    2013-08-06

    Reversible hydrogen storage in a LiBH{sub 4}:C{sub 60} nanocomposite (70:30 wt. %) synthesized by solvent-assisted mixing has been demonstrated. During the solvent-assisted mixing and nanocomposite formation, a chemical reaction occurs in which the C{sub 60} cages are significantly modified by polymerization as well as by hydrogenation (fullerane formation) in the presence of LiBH{sub 4}. We have determined that two distinct hydrogen desorption events are observed upon rehydrogenation of the material, which are attributed to the reversible formation of a fullerane (C{sub 60}H{sub x}) as well as a LiBH4 species. This system is unique in that the carbon species (C{sub 60}) actively participates in the hydrogen storage process which differs from the common practice of melt infiltration of high surface area carbon materials with LiBH{sub 4} (nanoconfinment effect). This nanocomposite demonstrated good reversible hydrogen storage properties as well as the ability to absorb hydrogen under mild conditions (pressures as low as 10 bar H{sub 2} or temperatures as low as 150°C). The nanocomposite was characterized by TGA-RGA, DSC, XRD, LDI-TOF-MS, FTIR, 1H NMR, and APPI MS.

  5. Dynamics and phase transitions in A{sub 1}C{sub 60} compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schober, H.; Toelle, A. [Institut Max von Laue - Paul Langevin, 38 -Grenoble (France); Renker, B.; Heid, R. [INFP, Forschungszentrum Karlsruhe, D-76021, Karlsruhe (Germany)

    1997-06-01

    We present an overview of extensive inelastic neutron scattering experiments carried out on powders of A{sub 1}C{sub 60}. The various phases leave strong fingerprints in the microscopic dynamics confirming the solid-state chemical reactions. The strong kinetic phase transitions can be followed in real time and turn to be highly complex. (orig.).

  6. Separation of C/sub 3+/ hydrocarbons by absorption and rectification

    Energy Technology Data Exchange (ETDEWEB)

    Sapper, R.

    1989-02-21

    A process for separation of C/sub 3+/ hydrocarbons from natural gas and the like comprises subjecting the gas under pressure to partial condensation under cooling, separating the uncondensed gaseous phase and engine expanding same while the condensed liquid fraction is subjected to rectification. Additional C/sub 3+/ hydrocarbons are separated from the engine expanded gaseous fraction by a scrubbing step. The loaded scrubbing agent is preferably fed to the rectification column, while the unabsorbed gaseous fraction coming from the scrubbing step is preferably heated and delivered as a product stream containing C/sub 2-/ hydrocarbons. In a preferred embodiment of the invention, scrubbing is conducted at a higher pressure than rectification, for example, about 10 to 20 bar higher than the rectification pressure. This proves to be especially advantageous if the C/sub 2-/ fraction is to be delivered under energy-intensive recompression is required. The scrubbing step is preferably performed with a liquid hydrocarbon mixture derived from the process itself, although other scrubbing agents, particularly other liquid hydrocarbon mixtures, are suitable. In a particularly preferred embodiment of the invention, the scrubbing is conducted with a scrubbing agent obtained by partial condensation of the residual gas from the rectification column. In another preferred embodiment of the invention, the partial condensation of the residual gas is conducted by heat exchange with the evaporating bottoms product from the scrubbing step. 1 fig.

  7. Regular approach for generating van der Waals C{sub s} coefficients to arbitrary orders

    Energy Technology Data Exchange (ETDEWEB)

    Ovsiannikov, Vitali D [Department of Physics, Voronezh State University, 394006 Voronezh (Russian Federation); Mitroy, J [Faculty of Technology, Charles Darwin University, Darwin, NT 0909 (Australia)

    2006-01-14

    A completely general formalism is developed to describe the energy E{sup disp} = {sigma}{sub s}C{sub s}/R{sup s} of dispersion interaction between two atoms in spherically symmetric states. Explicit expressions are given up to the tenth order of perturbation theory for the dispersion energy E{sup disp} and dispersion coefficients C{sub s}. The method could, in principle, be used to derive the expressions for any s while including all contributing orders of perturbation theory for asymptotic interaction between two atoms. The theory is applied to the calculation of the complete series up to s = 30 for two hydrogen atoms in their ground state. A pseudo-state series expansion of the two-atom Green function gives rapid convergence of the series for radial matrix elements. The numerical values of C{sub s} are computed up to C{sub 30} to a relative accuracy of 10{sup -7} or better. The dispersion coefficients for the hydrogen-antihydrogen interaction are obtained from the H-H coefficients by simply taking the absolute magnitude of C{sub s}.

  8. The combination reaction of CH{sub 3} and C{sub 6}H{sub 5}O

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C.Y. [Catholic Univ. of America, Washington, DC (United States). Dept. of Chemistry; Lin, M.C. [Naval Research Lab., Washington, DC (United States). Chemistry Div.

    1993-10-01

    Kinetics and mechanism of the CH{sub 3} + C{sub 6}H{sub 5}O reaction have been examined by means of the RRKM theory and kinetic modeling. Both the high temperature shock tube data for the production of cresols and the low temperature branching ratios (for production of cresols vs. methylcyclohexadienones, CH{sub 3}C{sub 6}H{sub 5}O) derived from Mulcahy and William`s data on the pyrolysis of di-t-butyl peroxide and phenol mixtures (Ref. 1) could be reasonably accounted for by the mechanism: CH{sub 3} + C{sub 6}H{sub 5}O {yields} CH{sub 3}C{sub 6}H{sub 5}O{sup +} {yields} o- and p-CH{sub 3}C{sub 6}H{sub 4}OH +M {yields} CH{sub 3}C{sub 6}H{sub 5}O. The energy barrier for the thermal iosmerization of CH{sub 3}C{sub 6}H{sub 5}O to cresols was estimated to be {approximately}132 kJ mol{sup {minus}1}.

  9. Downregulation of CX3CR1 ameliorates experimental colitis: evidence for CX3CL1-CX3CR1-mediated immune cell recruitment.

    Science.gov (United States)

    Becker, Felix; Holthoff, Christina; Anthoni, Christoph; Rijcken, Emile; Alexander, J Steven; Gavins, Felicity N E; Spiegel, H U; Senninger, Norbert; Vowinkel, Thorsten

    2017-03-01

    Inflammatory conditions like inflammatory bowel diseases (IBD) are characterized by increased immune cell infiltration. The chemokine ligand CX3CL1 and its receptor CX3CR1 have been shown to be involved in leukocyte adhesion, transendothelial recruitment, and chemotaxis. Therefore, the objective of this study was to describe CX3CL1-CX3CR1-mediated signaling in the induction of immune cell recruitment during experimental murine colitis. Acute colitis was induced by dextran sodium sulfate (DSS), and sepsis was induced by injection of lipopolysaccharide (LPS). Serum concentrations of CX3CR1 and CX3CL1 were measured by ELISA. Wild-type and CX3CR1(-/-) mice were challenged with DSS, and on day 6, intravital microscopy was performed to monitor colonic leukocyte and platelet recruitment. Intestinal inflammation was assessed by disease activity, histopathology, and neutrophil infiltration. CX3CR1 was upregulated in DSS colitis and LPS-induced sepsis. CX3CR1(-/-) mice were protected from disease severity and intestinal injury in DSS colitis, and CX3CR1 deficiency resulted in reduced rolling of leukocytes and platelets. In the present study, we provide evidence for a crucial role of CX3CL1-CX3CR1 in experimental colitis, in particular for intestinal leukocyte recruitment during murine colitis. Our findings suggest that CX3CR1 blockade represents a potential therapeutic strategy for treatment of IBD.

  10. Thermochemical Study on Ternary Solid Complex of La(Gly)2(Ala)3Cl3·2H2O (s)

    Institute of Scientific and Technical Information of China (English)

    Ye Lijuan; Li Qiangguo; Li Xu; Yang Dejun; Liu Yi

    2007-01-01

    The complex of lanthanum chloride with Glycine and Alanine, La(Gly)2(Ala)3Cl3·2H2O, was synthesized and characterized by IR, elementary analysis, thermogravimetric analysis, and chemical analysis. The dissolution enthalpies of LaCl3 ·7H2O(s), 2Gly(s) + 3Ala(s) and La(Gly)2(Ala)3Cl3 ·2H2O(s) were determined in 2 mol·L-1 HCl by a solution-reaction isoperibol calorimeter. By designing a thermochemical cycle in terms of Hess′ Law and through calculation, the reaction enthalpy of lanthanum chloride seven-hydrate with Glycine and Alanine was obtained: ΔrHθm (298.15 K)=(29.652±0.504) kJ·mol-1, and the standard enthalpy of formation of La(Gly)2(Ala)3Cl3·2H2O(s) ΔfHθm [La(Gly)2(Ala)3Cl3·2H2O, s, 298.15 K]=-4467.6±8.3 kJ·mol-1.

  11. Comparison on Mechanical Properties of SA508 Gr.3 Cl.1, Cl.2, and Gr.4N Low Alloy Steels for Pressure Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min-Chul; Park, Sang-Gyu; Lee, Bong-Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Ki-Hyoung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-10-15

    In this study, microstructure and mechanical properties of SA508 Gr.3 Cl. 1, Cl.2, and Gr.4N low alloy steels are characterized to compare their properties. To evaluate the fracture toughness in the transition region, the master curve method according to ASTM E1921 was adopted in the cleavage transition region. Tensile tests and Charpy impact tests were also performed to evaluate the mechanical properties, and a microstructural investigation was carried out. The microstructure and mechanical properties of SA508 Gr.3 Cl.1, Cl2 and Gr.4N low alloy steels were characterized.. The predominant microstructure of SA508 Gr.4N model alloy is tempered martensite, while SA508 Gr.3 Cl.1 and Cl.2 steels show a typical tempered upper bainitic structure. SA508 Gr. 4N model alloy shows the best strength and transition behavior among the three SA508 steels. SA508 Gr.3 Cl.2 steel also has quite good strength, but there is a loss of toughness.

  12. Fibroblast growth factor receptor 1 activation in mammary tumor cells promotes macrophage recruitment in a CX3CL1-dependent manner.

    Directory of Open Access Journals (Sweden)

    Johanna R Reed

    Full Text Available Tumor formation is an extensive process requiring complex interactions that involve both tumor cell-intrinsic pathways and soluble mediators within the microenvironment. Tumor cells exploit the intrinsic functions of many soluble molecules, including chemokines and their receptors, to regulate pro-tumorigenic phenotypes that are required for growth and progression of the primary tumor. Previous studies have shown that activation of inducible FGFR1 (iFGFR1 in mammary epithelial cells resulted in increased proliferation, migration, and invasion in vitro and tumor formation in vivo. These studies also demonstrated that iFGFR1 activation stimulated recruitment of macrophages to the epithelium where macrophages contributed to iFGFR1-mediated epithelial cell proliferation and angiogenesis. The studies presented here further utilize this model to identify the mechanisms that regulate FGFR1-induced macrophage recruitment. Results from this study elucidate a novel role for the inflammatory chemokine CX3CL1 in FGFR1-induced macrophage migration. Specifically, we illustrate that activation of both the inducible FGFR1 construct in mouse mammary epithelial cells and endogenous FGFR in the triple negative breast cancer cell line, HS578T, leads to expression of the chemokine CX3CL1. Furthermore, we demonstrate that FGFR-induced CX3CL1 is sufficient to recruit CX3CR1-expressing macrophages in vitro. Finally, blocking CX3CR1 in vivo leads to decreased iFGFR1-induced macrophage recruitment, which correlates with decreased angiogenesis. While CX3CL1 is a known target of FGF signaling in the wound healing environment, these studies demonstrate that FGFR activation also leads to induction of CX3CL1 in a tumor setting. Furthermore, these results define a novel role for CX3CL1 in promoting macrophage recruitment during mammary tumor formation, suggesting that the CX3CL1/CX3CR1 axis may represent a potential therapeutic approach for targeting breast cancers associated

  13. Structural organization of C{sub 60} fullerene, doxorubicin, and their complex in physiological solution as promising antitumor agents

    Energy Technology Data Exchange (ETDEWEB)

    Prylutskyy, Yu. I. [Taras Shevchenko National University of Kyiv (Ukraine); Evstigneev, M. P., E-mail: max-evstigneev@mail.ru [Belgorod State University, Department of Biology and Chemistry (Russian Federation); Cherepanov, V. V. [Institute of Physics of NAS of Ukraine (Ukraine); Kyzyma, O. A.; Bulavin, L. A.; Davidenko, N. A. [Taras Shevchenko National University of Kyiv (Ukraine); Scharff, P. [Ilmenau University of Technology (Germany)

    2015-01-15

    Specific features of structural self-organization of C{sub 60} fullerene (1 nm size range), antitumor antibiotic doxorubicin (Dox) and their complex in physiological solution (0.9 % NaCl) have been investigated by means of atomic-force microscopy, dynamic light scattering, and small-angle X-ray scattering. Significant ordering of the mixed system, C{sub 60} + Dox, was observed, suggesting the complexation between these drugs, and giving insight into the mechanism of enhancement of Dox antitumor effect on simultaneous administration with C{sub 60} fullerene.

  14. Potential groundwater age tracer found: Halon-1301 (CF3Br), as previously identified as CFC-13 (CF3Cl)

    Science.gov (United States)

    Beyer, Monique; van der Raaij, Rob; Morgenstern, Uwe; Jackson, Bethanna

    2014-09-01

    Groundwater dating using anthropogenic and natural tracer substances is a powerful tool for understanding groundwater dynamics for improved management of groundwater resources. Due to limitations in individual dating methods, often multiple tracers are used to reduce ambiguities. It is commonly accepted that there is a need for further complementary age tracers, in addition to current ones (e.g., tritium, SF6, and CFCs). We propose a potential new groundwater age tracer, Halon-1301 (CF3Br), which can easily be determined using gas chromatography with an attached electron capture detector (GC/ECD) developed by Busenberg and Plummer (2008). Its peak was noted by Busenberg and Plummer (2008), but they believed it to be CFC-13 (CF3Cl) at that time. We performed rigorous tests on gases containing or excluding Halon-1301 and CFC-13 and modern water samples and concluded that the two compounds have extremely similar retention times. Additionally, we found that the ECD response of CFC-13 is far too low to be detected in groundwater or air using standard volumes and sampling techniques. However, the peak areas and concentrations Busenberg and Plummer (2008) reported are in line with what would be expected for Halon-1301. Thus, we are confident that the peak formerly identified as CFC-13 is actually Halon-1301. Busenberg agrees with our findings. We further suggest that Halon-1301 has potential as a (complementary) age tracer, due to its established atmospheric history, and could hypothetically be used to date groundwater recharged in the 1970s or onward. We discuss known relevant properties, such as solubility and stability of Halon-1301 in the context of how these effect its potential application as a groundwater age tracer. Some open questions remain concerning how conservative Halon-1301 is—is it subject to degradation, retardation, and/or local contamination in groundwater. We are confident that Halon-1301 possesses important tracer relevant properties, but further

  15. Study of C{sub 60} {center_dot} 2S{sub 8} by the methods of induced electron emission

    Energy Technology Data Exchange (ETDEWEB)

    Shul`ga, Yu.M.; Rubtsov, V.I.; Lobach, A.S. [Institute of Chemical Physics, Moscow (Russian Federation)] [and others

    1994-12-01

    It was shown by the methods of induced electron emission that a transfer of the electron density from C{sub 60} molecules to the eight-membered ring of sulfur is characteristic of C{sub 60} {center_dot} 2S{sub 8}. The value of the ({sigma}+{pi})-plasmon energy for C{sub 60} {center_dot} 2S{sub 8} is approximately 1 eV less than that for pure C{sub 60}. In a high vacuum, the C{sub 60} {center_dot} 2S{sub 8} surface is depleted in sulfur.

  16. Communication: Electrical rectification of C{sub 59}N: The role of anchoring and doping sites

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, Sherif Abdulkader, E-mail: sherif.abbas@sydney.edu.au; Stampfl, C. [School of Physics, The University of Sydney, Sydney, New South Wales 2006 (Australia); Cui, X. Y.; Ringer, S. P. [Australian Centre for Microscopy and Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006 (Australia)

    2016-01-14

    Based on the nonequilibrium Green’s function formalism and density-functional theory, we investigate the onset of electrical rectification in a single C{sub 59}N molecule in conjunction with gold electrodes. Our calculations reveal that rectification is dependent upon the anchoring of the Au atom on C{sub 59}N; when the Au electrode is singly bonded to a C atom (labeled here as A), the system does not exhibit rectification, whereas when the electrode is connected to the C–C bridge site between two hexagonal rings (labeled here as B), transmission asymmetry is observed, where the rectification ratio reaches up to 2.62 at ±1 V depending on the N doping site relative to the anchoring site. Our analysis of the transmission mechanism shows that N doping of the B configuration causes rectification because more transmission channels are available for transmission in the B configuration than in the A configuration.

  17. Surfactant-free fabrication of fullerene C{sub 60} nanotubules under shear

    Energy Technology Data Exchange (ETDEWEB)

    Vimalanathan, Kasturi; Raston, Colin L. [Flinders Centre for NanoScale Science Technology (CNST) Chemical and Physical Sciences, Flinders University, Adelaide (Australia); Shrestha, Rekha Goswami [International Centre for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki (Japan); Zhang, Zhi; Zou, Jin [Materials Engineering and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, QLD (Australia); Nakayama, Tomonobu [International Centre for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Ibaraki (Japan)

    2017-07-10

    A method for controlling the self-assembly of fullerene C{sub 60} molecules into nanotubules in the fcc phase, devoid of entrapped solvent, has been established in a thin film microfluidic device. The micron length C{sub 60} nanotubules, with individual hollow diameters of 100 to 400 nm, are formed under continuous flow processing during high shear micromixing of water and a toluene solution of the fullerene, in the absence of surfactant, and without the need for further down-stream processing. TEM revealed pores on the surface of the nanotubes, and the isolated material has a much higher response to small molecule sensing than that for analogous material formed using multistep batch processing. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Scattering mechanisms in Rb-doped single-crystal C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, V.H.; Cohen, M.L. [Department of Physics, University of California at Berkeley, Berkeley, California 94720 (United States)]|[Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)

    1995-08-01

    The temperature-dependent resistivity of Rb-doped single-crystal C{sub 60} is analyzed within Bloch-Boltzmann transport theory yielding values of the electron-phonon coupling constant consistent with a superconducting {ital T}{sub {ital c}}{approx}30 K and isotope effect exponent {alpha}{approx}0.37 as long as the coupling is not primarily to the on-ball phonons of highest frequency. Disparate sources of information regarding the absolute magnitude of the resistivity are discussed in an attempt to form a more unified picture of the normal state and superconducting properties of both K-doped and Rb-doped C{sub 60}.

  19. Sputtering of Ag under C{sub 60}{sup +} and Ga{sup +} projectile bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Sun, S.; Szakal, C.; Smiley, E.J.; Postawa, Z.; Wucher, A.; Garrison, B.J.; Winograd, N

    2004-06-15

    Cluster ion bombardment often results in large secondary ion yield enhancements relative to atomic ion bombardment. The yields of neutral particles and secondary ions sputtered from a silver surface were investigated through experiments and molecular dynamics (MD) computer simulations. The results show that the neutral Ag yield produced by 15 keV C{sub 60}{sup +} bombardment is 5.6-fold higher than that found for 15 keV Ga{sup +} bombardment, which is in agreement with simulations. The enhancement effect is observed to be about the same for both neutral species and their corresponding secondary ions. Experimental results also indicate that the Ag neutral species produced by C{sub 60}{sup +} bombardment have emission velocity distributions that maximize at much lower values than those observed by Ga{sup +} bombardment, suggesting the presence of non-linear collision cascades.

  20. The far-infrared spectrum of crystalline C[sub 60

    Energy Technology Data Exchange (ETDEWEB)

    Bini, R.; Procacci, P.; Salvi, P.R.; Schettino, V. (Universita di Firenze (Italy))

    1993-10-14

    The infrared spectrum of crystalline C[sub 60] has been measured in the frequency range 500-20 cm[sup [minus]1] at various temperatures between 300 and 10 K. Since no dipole-allowed intramolecular vibration is active below 500 cm[sup [minus]1], the infrared absorption is determined by crystal and quadrupolar interactions. Davydov splittings of several intramolecular vibrations have been observed. The infrared activity of H[sub g] modes is discussed. In the lattice region the two translational phonons of T[sub u] symmetry are observed at 41 and 58.5 cm[sup [minus]1] at 8 K. Considerations on the order-disorder phase transition of C[sub 60] crystal are advanced on the basis of our experimental results. 39 refs., 6 figs., 3 tabs.

  1. Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2015. Part 1. C{sub 1} − C{sub 10}

    Energy Technology Data Exchange (ETDEWEB)

    Acree, William [Department of Chemistry, University of North Texas, Denton, Texas 76203 (United States); Chickos, James S. [Department of Chemistry and Biochemistry, University of Missouri—St. Louis, One University Boulevard, St. Louis, Missouri 63121 (United States)

    2016-09-15

    A compendium of phase change enthalpies published in 2010 is updated to include the period 1880–2015. Phase change enthalpies including fusion, vaporization, and sublimation enthalpies are included for organic, organometallic, and a few inorganic compounds. Part 1 of this compendium includes organic compounds from C{sub 1} to C{sub 10}. Part 2 of this compendium, to be published separately, will include organic and organometallic compounds from C{sub 11} to C{sub 192}. Sufficient data are presently available to permit thermodynamic cycles to be constructed as an independent means of evaluating the reliability of the data. Temperature adjustments of phase change enthalpies from the temperature of measurement to the standard reference temperature, T = 298.15 K, and a protocol for doing so are briefly discussed.

  2. Unusual rearrangement in the photochemical addition of bis(alkylidene)disilacyclobutanes to C[sub 60

    Energy Technology Data Exchange (ETDEWEB)

    Kusukawa, Takahiro; Kabe, Yoshio; Erata, Tomoki; Nestler, B.; Ando, Wataru (Univ. of Tsukuba (Japan))

    1994-11-01

    The photochemical reaction of bis(alkylidene)-disilacyclobutanes 1a, b with C[sub 60] afforded the stable 1:1 adducts 3a,b, resulting from an unexpected rearrangement of the disilacyclobutane unit. The structures of 3a,b were determined by spectroscopic methods, including [sup 29]Si-[sup 1]H HMBC hetero nuclear shift correlation experiments. 18 refs., 2 figs.

  3. Biodistribution and tumor uptake of C{sub 60}(OH){sub x} in mice

    Energy Technology Data Exchange (ETDEWEB)

    Ji Zhiqiang; Sun Hongfang, E-mail: shf@pku.edu.cn; Wang Haifang; Xie Qunying; Liu Yuangfang [Peking University, Department of Chemical Biology, College of Chemistry and Molecular Engineering (China); Wang Zheng [Chinese Academy of Medical Sciences, Cancer Institute (China)

    2006-02-15

    Radiolabeling of fullerol, {sup 125}I-C{sub 60}(OH){sub x}, was performed by the traditional chloramine-T method. The C-I covalent bond in I-C{sub 60}(OH){sub x} was characterized by X-ray photoelectron spectroscopy (XPS) that was sufficiently stable for in vivo study. Laser light scattering spectroscopy clearly showed that C{sub 60}(OH){sub x} aggregated to large nanoparticle clumps with a wide range of distribution. The clumps formed were also visualized by transmission electron microscope (TEM). We examined the biodistribution and tumor uptake of C{sub 60}(OH){sub x} in five mouse bearing tumor models, including mouse H22 hepatocarcinoma, human lung giantcellcarcinoma PD, human colon cancer HCT-8, human gastric cancer MGC803, and human OS732 osteosarcoma. The accumulation ratios of {sup 125}I-C{sub 60}(OH){sub x} in mouse H22 hepatocarcinoma to that in normal muscle tissue (T/N) and blood (T/B) at 1, 6, 24 and 72 h, reveal that {sup 125}I-C{sub 60}(OH){sub x} gradually accumulates in H22 tumor, and retains for a quite long period (e.g., T/N 3.41, T/B 3.94 at 24 h). For the other four tumor models, the T/N ratio at 24 h ranges within 1.21-6.26, while the T/B ratio ranges between 1.23 and 4.73. The accumulation of C{sub 60}(OH){sub x} in tumor is mostly due to the enhanced permeability and retention effect (EPR) and the phagocytosis of mononuclear phagocytes. Hence, C{sub 60}(OH){sub x} might serve as a photosensitizer in the photodynamic therapy of some kinds of tumor.

  4. Characterization of Al–Al{sub 4}C{sub 3} nanocomposites produced by mechanical milling

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Beltrán, A., E-mail: asantos@utchsur.edu.mx [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Goytia-Reyes, R. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico); Morales-Rodriguez, H.; Gallegos-Orozco, V. [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Santos-Beltrán, M. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico); Baldenebro-Lopez, F. [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Martínez-Sánchez, R. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico)

    2015-08-15

    In this work, a mixture of Al–C–Al{sub 4}C{sub 3} nanopowder previously synthesized by mechanical milling and subsequent thermal treatment was used to reinforce the Al matrix. The nanocomposites were fabricated via high-energy ball milling and subsequent sintering process for different periods of time at 550 °C. Hardness and compression tests were performed to evaluate the mechanical properties of the nanocomposites in the as-milled and sintered conditions. According to the results the reinforcement located in the grain boundaries is responsible for the brittle behavior observed in the nanocomposites during the compression test. The combined effect of sintering and precipitation mechanisms produced an evident increase of the strength of the Al matrix at a relatively short sintering time. By using the Rietveld method the crystallite size and microstrain measurements were determined and correlated with the microhardness values. For the proper characterization of the nanoparticles present in the Al matrix, atomic force microscopy and high resolution electron microscopy were used. - Highlights: • Nanostructured Al{sub 4}C{sub 3} reinforcement was fabricated via mechanical milling and heat treatment. • We found a significant increase of the mechanical properties at short sintering times. • The formation of Al{sub 4}C{sub 3} with during sintering time restricted the excessive growth of the crystallite. • Al{sub 4}C{sub 3} located in the grain boundaries causes brittle fracture observed in compression tests. • There is a correlation between, crystallite size and microstrain values with microhardness.

  5. C>4 and CAM Plant Biology Symposium 2013 Website

    Energy Technology Data Exchange (ETDEWEB)

    Leakey, Andrew D. B. [Univ. of Illinois, Champaign, IL (United States)

    2013-08-09

    This project funded the C>4 and CAM (crassulacean acid metabolism) Plant Biology 2013 symposium, held at the University of Illinois at Urbana-Champaign, IL, on August 6-9, 2013. The symposium brought together a diverse group of scientists to discuss the evolution, ecology, functional biology, genomics and biotechnological engineering of C>4 and CAM plants. These two groups of plants possess evolutionary modifications to their photosynthetic machinery that improve their performance in hot and dry conditions. Maize and pineapple are classic examples of C>4 and CAM plants, respectively. The meeting discussed how lessons learned from these groups of plants can be harnessed to improve crop production of biofuel feedstocks in an era of global climate change. The interdisciplinary nature of the meeting meant that the delegation members typically do not collectively attend any one scientific society meeting. As a result, the symposium was a unique opportunity for knowledge transfer, initiation of new collaborations, and recruitment and exposure of early career scientists.

  6. V{sub 18}P{sub 9}C{sub 2}. A complex phosphide carbide

    Energy Technology Data Exchange (ETDEWEB)

    Boller, Herbert [Linz Univ. (Austria). Inst. fuer Anorganische Chemie; Effenberger, Herta [Wien Univ. (Austria). Inst. fuer Mineralogie und Kristallographie

    2016-08-01

    V{sub 18}P{sub 9}C{sub 2} crystallizes in the orthorhombic space group Pmma with the lattice parameters a = 17.044(3), b = 3.2219(7), and c = 13.030(2) Aa, Z = 2. The crystal structure is composed of 19 symmetry-independent atoms. The crystal structure is considered as a network formed by the transition metal atoms exhibiting cubic, trigonal prismatic, and octahedral voids centered by V, P, and C atoms, respectively. Vice versa, the V and P atoms form a three-dimensional network. The two CV{sub 6} octahedra are edge- and corner-connected to chains running parallel to [010]. The five unique P atoms are trigonal prismatically coordinated by V atoms with one to three faces capped again by a V atom. The V atoms have mainly cubic environments formed solely by V or by V and P atoms. V{sub 18}P{sub 9}C{sub 2} exhibits some structural relations to other compounds of the ternary system V-P-C as well as to other intermetallic phases. Despite the low carbon content, V{sub 18}P{sub 9}C{sub 2} is considered as a ternary compound rather than an interstitially stabilized (binary) phosphide in view of its special structural features.

  7. Absolute photoabsorption cross section of C{sub 60} in the extreme ultraviolet

    Energy Technology Data Exchange (ETDEWEB)

    Mori, T. [Department of Vacuum UV Photoscience, Institute for Molecular Science, Myodaiji, Okazaki 444-8585 (Japan); Kou, J. [Department of Vacuum UV Photoscience, Institute for Molecular Science, Myodaiji, Okazaki 444-8585 (Japan); Haruyama, Y. [Department of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530 (Japan); Kubozono, Y. [Department of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530 (Japan); Mitsuke, K. [Department of Vacuum UV Photoscience, Institute for Molecular Science, Myodaiji, Okazaki 444-8585 (Japan) and Graduate University for Advanced Studies, Myodaiji, Okazaki 444-8585 (Japan)]. E-mail: mitsuke@ims.ac.jp

    2005-06-15

    The absolute photoabsorption cross section curve of C{sub 60} has been determined by means of mass spectrometry with the photon source of monochromatized synchrotron radiation of h{nu} = 24.5-150 eV. Description has been made on a high-temperature source of gaseous fullerenes and an efficient time-of-flight mass spectrometer. The cross section was estimated by assuming an approximate expression of the number density of C{sub 60} in the ionization region. The resultant values were 762, 241, and 195 Mb at h{nu} = 24.5, 90, and 110 eV, respectively, with about 10% errors. The cross section curve was then normalized at h{nu} = 25 eV to the absolute photoabsorption cross section reported by Jaensch and Kamke [R. Jaensch, W. Kamke, Mol. Mater. 13 (2000) 143], the most reliable data so far available in the valence excitation region of C{sub 60}. Accordingly, the present cross section data were altered to 407, 144, and 114 Mb at h{nu} = 25, 90, and 110 eV, respectively.

  8. Softening of the elastic shear mode C{sub 66} in iron-based superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Boehmer, Anna; Burger, Philipp [Karlsruher Institut fuer Technologie, Institut fuer Festkoerperphysik, D-76021 Karlsruhe (Germany); Karlsruher Institut fuer Technologie, Fakultaet fuer Physik, D-76128 Karlsruhe (Germany); Hardy, Frederic; Schweiss, Peter; Fromknecht, Rainer; Wolf, Thomas; Meingast, Christoph [Karlsruher Institut fuer Technologie, Institut fuer Festkoerperphysik, D-76021 Karlsruhe (Germany); Reinecker, Marius; Schranz, Wilfried [Universitaet Wien, Fakultaet fuer Physik, A-1090 Wien, Vienna (Austria)

    2013-07-01

    The structural phase transition of underdoped iron-based superconductors is accompanied by a large softening of the elastic shear mode C{sub 66}, which has attracted considerable attention. This softening has been discussed both in terms of orbital and spin-nematic fluctuations which would be responsible for the structural phase transition and, possibly, superconductivity. However, sample requirements have so far restricted experimental investigations of C{sub 66} (via measurements of the ultrasound velocity) to the Ba(Fe,Co){sub 2}As{sub 2} system. Here, we report on a new technique, based on a three-point bending setup, to probe the Young's modulus of a sample with a capacitance dilatometer. For certain orientations, the Young's modulus is related to the elastic constant C{sub 66} whose effective temperature dependence can be obtained. Platelet-like samples, as frequently encountered for iron-based systems, are easily studied with our setup. Data on several systems are presented and discussed.

  9. Enhancement of ambipolar characteristics in single-walled carbon nanotubes using C{sub 60} and fabrication of logic gates

    Energy Technology Data Exchange (ETDEWEB)

    Park, Steve [Department of Materials Science and Engineering, Stanford University, Durand Building, 496 Lomita Mall, Stanford, California 94305-4034 (United States); Nam, Ji Hyun [Department of Electrical Engineering, Stanford University, David Packard Building, 350 Serra Mall, Mail Code: 9505, Stanford, California 94305-9505 (United States); Koo, Ja Hoon; Lei, Ting; Bao, Zhenan, E-mail: zbao@stanford.edu [Department of Chemical Engineering, Stanford University, Shriram Center, 443 Via Ortega, Room 307, Stanford, California 94305-4145 (United States)

    2015-03-09

    We demonstrate a technique to convert p-type single-walled carbon nanotube (SWNT) network transistor into ambipolar transistor by thermally evaporating C{sub 60} on top. The addition of C{sub 60} was observed to have two effects in enhancing ambipolar characteristics. First, C{sub 60} served as an encapsulating layer that enhanced the ambipolar characteristics of SWNTs. Second, C{sub 60} itself served as an electron transporting layer that contributed to the n-type conduction. Such a dual effect enables effective conversion of p-type into ambipolar characteristics. We have fabricated inverters using our SWNT/C{sub 60} ambipolar transistors with gain as high as 24, along with adaptive NAND and NOR logic gates.

  10. Effect of C{sub 60} as an electron buffer layer in polythiophene-methanofullerene based bulk heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Elumalai, Naveen Kumar; Peining, Zhu [Department of Mechanical Engineering, National University of Singapore (Singapore); Yin, Leung Man; Chellappan, Vijila; Jie, Zhang [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore (Singapore); Ramakrishna, Seeram [Department of Mechanical Engineering, National University of Singapore (Singapore); Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore (Singapore); Faculty of Science, King Saud University, Riyadh (Algeria)

    2012-08-15

    The effect of C{sub 60} interlayer on charge transport and device performance in bulk heterojunction solar cells with active layer of poly3-hexylthiophene (P3HT) and l-3-methoxycarbonyl-propyl-l-phenyl-6,6 methanofullerene (PCBM) have been studied. The C{sub 60} layer of different thicknesses (5 nm, 10 nm, 15 nm, and 20 nm) was introduced between the cathode and the photoactive layer of the solar cell. The solar cell performance was found to be maximized at an optimum C{sub 60} thickness of about 5 nm. Subsequent increase in C{sub 60} interlayer thickness promotes charge transfer near the Al-C{sub 60} interface due to increased diffusion of Al atoms into the interstitials of C{sub 60}. This results in the formation of s-shaped kink in J-V spectra. To further investigate the cause of this detrimental effects, photoinduced charge extraction by linearly increasing voltage (PhotoCELIV) and CELIV studies were performed on the real solar cell devices. The CELIV transients obtained from the device with 5 nm C{sub 60} interlayer shows no charge extraction peak whereas the devices with C{sub 60} layer of thicknesses from 10 nm to 20 nm shows characteristic maxima due to the transferred charge carriers from the Al-C{sub 60} interface. The PhotoCELIV studies performed on the devices showed characteristic single peak for the device with 5 nm C{sub 60} interlayer whereas the other devices exhibited dual peaks due to charges generated from photo excitation and injection at the interface respectively. The charge mobility values calculated from the dual photoCELIV transients indicates the charge mobility imbalance between the carriers in the devices. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. C{sub 24}H{sub 14} polycyclic aromatic hydrocarbons from the pyrolysis of catechol

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.; Wornat, M.J. [Louisiana State University, Baton Rouge, LA (United States). Dept. of Chemical Engineering

    2008-07-01

    Polycyclic aromatic hydrocarbons (PAH) of the C{sub 24}H{sub 14} isomer class, some of which are potent mutagens and carcinogens, are produced during the burning of solid fuels. For a clearer understanding of the formation of PAH, pyrolysis experiments have been performed in an isothermal laminar-flow reactor with the model fuel catechol (ortho-dihydroxybenzene) - a phenol-type compound representative of structural entities in complex solid fuels like coal, wood, and biomass. The catechol pyrolysis experiments are conducted at 1000{sup o}C and at a residence time of 0.3 s. The pyrolysis products are analysed by high-pressure liquid chromatography with ultraviolet-visible absorbance detection and mass spectrometric detection. Product analysis reveals that the C{sub 24}H{sub 14} PAH products of catechol pyrolysis belong to three structural classes: perylene benzologues, fluoranthene benzologues and pyrene benzologues. The 12 C{sub 24}H{sub 14} PAH identified in the present study are: benzo(b)perylene, naphtho(1,2-b)fluoranthene, naphtho(1,2-k)fluoranthene, dibenzo(b,k)fluoranthene, naphtho(2,3-b)fluoranthene, naphtho(2,3-k)fluoranthene, naphtho(1,2-e)pyrene, naphtho(2,3-e)pyrene, naphtho(1,2-a)pyrene, dibenzo(a,e)pyrene, dibenzo(e, l)pyrene, and dibenzo(a,h)pyrene. In addition to these, our earlier identifications of naphtho(2,1-a)pyrene, naphtho(2,3-a)pyrene, and dibenzo(a,i)pyrene among the products of catechol pyrolysis bring the total number of C{sub 24}H{sub 14} PAH identified as products of catechol pyrolysis to 15. Of these 15, 12 have been reported to be mutagens and 6 have been reported to be carcinogens. The UV spectra establishing the identities of the 15 C{sub 24}H{sub 14} catechol pyrolysis products are presented.

  12. Water Assisted Growth of C>60 Rods and Tubes by Liquid–Liquid Interfacial Precipitation Method

    Directory of Open Access Journals (Sweden)

    Cheuk-Wai Tai

    2012-06-01

    Full Text Available C>60 nanorods with hexagonal cross sections are grown using a static liquid–liquid interfacial precipitation method in a system of C>60/m-dichlorobenzene solution and ethanol. Adding water to the ethanol phase leads instead to C>60 tubes where both length and diameter of the C>60 tubes can be controlled by the water content in the ethanol. Based on our observations we find that the diameter of the rods/tubes strongly depends on the nucleation step. We propose a liquid-liquid interface growth model of C>60 rods and tubes based on the diffusion rate of the good C>60 containing solvent into the poor solvent as well as on the size of the crystal seeds formed at the interface between the two solvents. The grown rods and tubes exhibit a hexagonal solvate crystal structure with m-dichlorobenzene solvent molecules incorporated into the crystal structure, independent of the water content. An annealing step at 200 °C at a pressure < 1 kPa transforms the grown structures into a solvent-free face centered cubic structure. Both the hexagonal and the face centered cubic structures are very stable and neither morphology nor structure shows any signs of degradation after three months of storage.

  13. Theoretical study of hydrogen adsorption on Ca-decorated C{sub 48}B{sub 12} clusters

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Pengtang; Chen, Hongshan, E-mail: chenhs@nwnu.edu.cn [Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China)

    2015-09-15

    The hydrogen adsorption on Ca-decorated C{sub 48}B{sub 12} clusters is studied using density functional theory. The favorable binding site for Ca atom is the hexagonal C{sub 4}B{sub 2} rings. The strong interaction between Ca atoms and C{sub 48}B{sub 12} cluster hinders the aggregation of Ca atoms on the cluster surface. C{sub 48}B{sub 12} is an electron deficient system with a large electron affinity of 2.952 eV. The decorated Ca atoms transfer their electrons to the cluster easily. The net charges on the Ca atoms are in the range of 1.101 to 1.563 e. When H{sub 2} molecules approach the Ca atoms, they are moderately polarized and adsorbed around the Ca atoms in molecular form. The adsorption strength can reach up to 0.133 eV/H{sub 2}. Each Ca atom in the Ca-decorated C{sub 48}B{sub 12} complexes can adsorb three H{sub 2} molecules. The fully decorated C{sub 48}B{sub 12}Ca{sub 6} can hold up to 18 H{sub 2} molecules.

  14. Conversion of single-crystalline C{sub 60} nanodisks and nanorods into graphitic nanostructures via hydrogen thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Lim, H; Song, H J; Choi, H C [Department of Chemistry, Pohang University of Science and Technology, San 31, Hyoja-Dong, Nam-Gu, Pohang 790-784 (Korea, Republic of); Shin, H S [UNIST (Ulsan National Institute of Science and Technology), Banyeon-ri 194, Ulsan 689-805 (Korea, Republic of)], E-mail: choihc@postech.edu

    2009-04-08

    We have developed a process to convert C{sub 60} nanostructures into graphitic nanostructures. Disk-shaped and wire-shaped C{sub 60} nanostructures synthesized by the liquid-liquid interfacial precipitation method, the vapor-solid process, and solvent evaporation were successfully converted into graphitic structures by thermal annealing in hydrogen at 900 deg. C. Scanning electron and tunneling electron microscopic studies confirmed that the converted nanostructures were composed of multi-graphitic structures such as multi-walled carbon nanotubes, carbon nanofibers, and carbon onions. Fourier transform Raman spectroscopy and conductance measurements were carried out to further confirm the successful formation of graphitic layers. In the Raman spectra, the nanostructures converted from C{sub 60} disks showed signature D, G, and G{sup '} bands of graphitic structures, while the A{sub g} mode (1469 cm{sup -1}) of the original C{sub 60} molecule disappeared. C{sub 60} nanowire devices fabricated for the conductance measurements of the converted structures showed dramatically decreased resistance (R{approx}100 k{omega}) compared to the pristine C{sub 60} wire (R>100 M{omega}). Further manipulation of the reaction environment, including the gas and the annealing temperature, may reveal a new way to attain diverse graphitic nanostructures economically.

  15. CX3CL1 (fractalkine and CX3CR1 expression in myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis: kinetics and cellular origin

    Directory of Open Access Journals (Sweden)

    Olsson Tomas

    2005-07-01

    Full Text Available Abstract Background Multiple sclerosis (MS is a chronic inflammatory disease of the central nervous system (CNS. It is associated with local activation of microglia and astroglia, infiltration of activated macrophages and T cells, active degradation of myelin and damage to axons and neurons. The proposed role for CX3CL1 (fractalkine in the control of microglia activation and leukocyte infiltration places this chemokine and its receptor CX3CR1 in a potentially strategic position to control key aspects in the pathological events that are associated with development of brain lesions in MS. In this study, we examine this hypothesis by analyzing the distribution, kinetics, regulation and cellular origin of CX3CL1 and CX3CR1 mRNA expression in the CNS of rats with an experimentally induced MS-like disease, myelin oligodendrocyte glycoprotein (MOG-induced autoimmune encephalomyelitis (EAE. Methods The expression of CX3CL1 and its receptor CX3CR1 was studied with in situ hybridization histochemical detection of their mRNA with radio labeled cRNA probes in combination with immunohistochemical staining of phenotypic cell markers. Both healthy rat brains and brains from rats with MOG EAE were analyzed. In defined lesional stages of MOG EAE, the number of CX3CR1 mRNA-expressing cells and the intensity of the in situ hybridization signal were determined by image analysis. Data were statistically evaluated by ANOVA, followed by Tukeyprimes multiple comparison test. Results Expression of CX3CL1 mRNA was present within neuronal-like cells located throughout the neuraxis of the healthy rat. Expression of CX3CL1 remained unaltered in the CNS of rats with MOG-induced EAE, with the exception of an induced expression in astrocytes within inflammatory lesions. Notably, the brain vasculature of healthy and encephalitic animals did not exhibit signs of CX3CL1 mRNA expression. The receptor, CX3CR1, was expressed by microglial cells in all regions of the healthy brain

  16. Fatigue crack growth behaviors of SA508 Gr.3 Cl.2 base and weld material in 290 .deg. C water environment

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Pyungyeon; Kim, Jeong Hyeon; Jang, Changheui [KAIST, Daejeon (Korea, Republic of); Cho, Hyunchul [Doosan Heavy Industries and Construction Co., Ltd., Changwon (Korea, Republic of)

    2012-04-15

    The fatigue crack growth behaviors of SA508 Gr.3 Cl.2 low alloy steel in high temperature water environment were investigated. Overall, weld metal showed similar crack growth rate as that of base metal. At 0.01 Hz, fatigue crack growth rate (FCGR) was higher than that in air while the difference was smaller at 0.1 Hz. Also, FCGR showed ΔK dependency at 0.1 Hz only, indicating that the environmental effect was much greater at slower loading frequency of 0.01 Hz. FCGR of SA508 Gr.3 Cl.2 low alloy steel was compatible to or smaller than the ASME Sec. XI fatigue reference curves in high temperature water environment.

  17. Doping of C[sub 60] films after ion implantation. Dopage de films de C[sub 60] par implantation ionique

    Energy Technology Data Exchange (ETDEWEB)

    Trouillas, P.; Ratier, B.; Moliton, A. (LEPOFI, Limoges (France). Faculte des Sciences); Gauneau, M. (Centre National d' Etudes des Telecommunications (CNET), 22 - Lannion (France)); Bernier, P. (Montpellier-2 Univ., 34 (France))

    1994-10-01

    With C[sub 60] films, ion implantation of inert ions (argon) gives rise to conduction processes ([sigma] > 10[sup 4] [Omega][sup -1] cm[sup -1]) related to degradation only in the case where implantation is performed at a high temperature (T = 560 K); no sample degeneracy ([sigma] < 10[sup -4] [Omega][sup -1] cm[sup -1]) appears after argon implantation at room temperature, but doping effects ([sigma] [approx] 1 [Omega][sup -1] cm[sup -1]) are obtained after implantation at room temperature with chemically active ions; with a fluence of the order of 10[sup 15] ions cm[sup -2], the thermoelectric power then appears negative with potassium or phosphorus ions, and positive with bromine or boron ions. (Author).

  18. Theoretical study of H-abstraction reactions from CH3Cl and CH3Br molecules by ClO and BrO radicals.

    Science.gov (United States)

    Canneaux, Sébastien; Hammaecher, Catherine; Cours, Thibaud; Louis, Florent; Ribaucour, Marc

    2012-05-03

    The rate constants of the H-abstraction reactions from CH(3)Cl and CH(3)Br molecules by ClO and BrO radicals have been estimated over the temperature range of 300-2500 K using four different levels of theory. Calculations of optimized geometrical parameters and vibrational frequencies are performed using B3LYP and MP2 methods combined with the cc-pVTZ basis set. Single-point energy calculations have been carried out with the highly correlated ab initio coupled cluster method in the space of single, double, and triple (perturbatively) electron excitations CCSD(T) using the cc-pVTZ and cc-pVQZ basis sets. Canonical transition-state theory combined with an Eckart tunneling correction has been used to predict the rate constants as a function of temperature. In order to choose the appropriate levels of theory with chlorine- and bromine-containing species, the reference reaction Cl ((2)P(3/2)) + CH(3)Cl → HCl + CH(2)Cl (R(ref)) was first theoretically studied because its kinetic parameters are well-established from numerous experiments, evaluation data, and theoretical studies. The kinetic parameters of the reaction R(ref) have been determined accurately using the CCSD(T)/cc-pVQZ//MP2/cc-pVTZ level of theory. This level of theory has been used for the rate constant estimation of the reactions ClO + CH(3)Cl (R(1)), ClO + CH(3)Br (R(2)), BrO + CH(3)Cl (R(3)), and BrO + CH(3)Br (R(4)). Six-parameter Arrhenius expressions have been obtained by fitting to the computed rate constants of these four reactions (including cis and trans pathways) over the temperature range of 300-2500 K.

  19. CsI Pre-Intercalation in the Inorganic Framework for Efficient and Stable FA1-x Csx PbI3 (Cl) Perovskite Solar Cells.

    Science.gov (United States)

    Zhou, Ning; Shen, Yiheng; Zhang, Yu; Xu, Ziqi; Zheng, Guanhaojie; Li, Liang; Chen, Qi; Zhou, Huanping

    2017-06-01

    Engineering the chemical composition of organic and inorganic hybrid perovskite materials is one of the most feasible methods to boost the efficiency of perovskite solar cells with improved device stability. Among the diverse hybrid perovskite family of ABX3 , formamidinium (FA)-based mixed perovskite (e.g., FA1-x Csx PbI3 ) possesses optimum bandgaps, superior optoelectronic property, as well as thermal- and photostability, which is proven to be the most promising candidate for advanced solar cell. Here, FA0.9 Cs0.1 PbI3 (Cl) is implemented as the light-harvesting layer in planar devices, whereas a low temperature, two-step solution deposition method is employed for the first time in this materials system. This paper comprehensively exploits the role of Cs(+) in the FA0.9 Cs0.1 PbI3 (Cl) perovskite that affects the precursor chemistry, film nucleation and grain growth, and defect property via pre-intercalation of CsI in the inorganic framework. In addition, the resultant FA0.9 Cs0.1 PbI3 (Cl) films are demonstrated to exhibit an improved optoelectronic property with an elevated device power conversion efficiency (PCE) of 18.6%, as well as a stable phase with substantial enhancement in humidity and thermal stability, as compared to that of FAPbI3 (Cl). The present method is able to be further extended to a more complicated (FA,MA,Cs)PbX3 material system by delivering a PCE of 19.8%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Exploring the dynamics of C/H and C/Cl exchanges in the C(3P) + C2H3Cl reaction

    Science.gov (United States)

    Lee, Shih-Huang; Chen, Wei-Kan; Chin, Chih-Hao; Huang, Wen-Jian

    2013-10-01

    The dynamics of the C(3P) + C2H3Cl reaction at collision energy 3.8 kcal mol-1 was investigated in a crossed molecular-beam apparatus using synchrotron vacuum-ultraviolet ionization. Time-of-flight spectra of products C3H2Cl, C3H3, and Cl were recorded at various laboratory scattering angles, from which translational-energy distributions and angular distributions of product channels C3H2Cl + H and C3H3 + Cl were derived. Cl correlates satisfactorily with C3H3 in linear momentum and angular distributions, which confirms the production of C3H3 + Cl. The H-loss (Cl-loss) channel has average translational-energy release 14.3 (8.8) kcal mol-1 corresponding to a fraction 0.30 (0.14) of available energy into the translational degrees of freedom of product HCCCHCl + H (H2CCCH + Cl). The branching ratio of channel H to channel Cl was determined approximately as 12:88. The measurements of translational-energy releases and photoionization thresholds cannot distinguish HCCCHCl from H2CCCCl because both isomers have similar enthalpy of formation and ionization energy; nevertheless, the Rice-Ramsperger-Kassel-Marcus calculation prefers HCCCHCl. The measurement of photoionization spectra identifies product C3H3 as H2CCCH (propargyl). Both products C3H2Cl + H and C3H3 + Cl might correlate to the same triplet intermediate H2CCCHCl but have distinct angular distributions; the former is nearly isotropic whereas the latter is forward biased. A comparison with the C(3P) + C2H3F reaction is stated.

  1. Synthesis and luminous characteristics of Ba IISiO 3Cl II:Eu 2+, Mn 2+ phosphor for white LED

    Science.gov (United States)

    Shen, Changyu; Yang, Yi; Jin, Shangzhong

    2007-11-01

    Ba IISiO 3Cl II:Eu 2+, Mn 2+ phosphor was synthesized by high-temperature solid state reaction at 900~1200°C in a slightly reducing atmosphere for 2.0~8.0 hours. The raw materials were the mixture of BaCO 3, SiO II, MnCO 3, NH 4Cl, and Eu IIO 3 in the mol ratio of 3, 2, 0.004, 2 and 0.02. Ba IISiO 3Cl II:Eu 2+, Mn 2+ phosphor's absorption and luminescence spectra were studied. The results indicated that the emission band consists of three peaks located at 425 nm, 492nm and 608nm, respectively. The emission peaks at 425 and 492nm originate from the transition 5d-->4f of Eu 2+ ions that occupy the two Ba 2+ sites in the crystal of Ba IISiO 3Cl II, while the 608nm emission is attributed to the energy transfer from Eu2+ ions to Mn 2+ ions. The white light can be obtained by mixing the three emission colors of blue (425 nm), green (492 nm) and red-orange (608 nm) in the single host. When the concentrations of the Eu 2+ ions and Mn 2+ ions were 0.02mol and 0.004mol respectively, the sample presented intense white emitting. The excitation spectra of the three emissions extending from 300 nm to 460 nm indicated that Ba IISiO 3Cl II:Eu 2+ phosphor can be excitated by InGaN chip UV emission effectively, and it is a single-phase white phosphor with low-cost and high brightness for white LEDs.

  2. Options for nitriles removal from C{sub 4}-C{sub 5} cuts. 3. Catalytic hydrogenation using the swing reactive removal process

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Corredores, M.M.; Hernandez, Z.; Guerra, J.; Alvarez, R.; Medina, J. [PDVSA Intevep, Refinacion y Petroquimica, Aptdo. 76343, Caracas 1070A (Venezuela)

    2003-05-15

    C{sub 4} and C{sub 5} cuts from FCC units can be useful in the preparation of oxygenates such as MTBE, ETBE, and TAME. However, these feedstocks typically contain nitriles and diolefins which poison the etherification catalyst. Albeit, in USA, strong concerns on oxygenate uses have given rise to prohibition within certain states, those concerns have not derived into such drastic decisions in Europe. Still, removing nitriles from reactive feedstocks or converting them into value-added products might be of interest. PDVSA Intevep has developed several methods for removing nitriles present in those feedstocks, which include one based on adsorption [M.M. Ramirez-Corredores, Z. Hernandez, J. Guerra, J. Medina, R. Alvarez. Submitted to Adsorption.], and two based on catalytic conversion. In the first part of this work [M.M. Ramirez-Corredores, Z. Hernandez, J. Guerra, J. Medina, R. Alvarez. Submitted to Adsorption.], both the adsorbent and the adsorption process were described. The details of the catalytic system for the simultaneous hydrogenation of nitriles and diolefins were given in the second part [M.M. Ramirez-Corredores, T. Romero, D. Djaouadi, Z. Hernandez, J. Guerra. Submitted to Ind. Eng. Chem. Res.]. The main features of the catalyst include its nitrile adsorption capabilities, the specific oxidation state of the metal active phase, and the strong early deactivation. In this work, we discuss the convenience of converting the nitriles and diolefins by using a swing mode of reaction between two (or more) reacting zones in order to overcome the drawbacks of the observed deactivation.

  3. Short-chain (C{sub 21} and C{sub 22}) diasteranes in petroleum and source rocks as indicators of maturity and depositional environment

    Energy Technology Data Exchange (ETDEWEB)

    Requejo, A.G. [Texas A & M Univ., College Station, TX (United States)]|[Exxon Production Research Co., Houston, TX (United States); McDonald, T.J.; Sassen, R. [Texas A & M Univ., College Station, TX (United States)] [and others

    1997-07-01

    Geochemical analysis of steranes in source rocks from the Western Canada Basin has allowed the identification of several C{sub 21} and C{sub 22} short-chain sterane isomers. The principal compounds in carbonates from the U. Jurassic Nordegg Formation have been identified as diginane and homodiginane, more thermodynamically-stable isomers of the compounds pregnane and homopregnane that have 5{alpha}, 14{beta},17{beta}(H) stereochemistry. The Triassic Doig formation also contains two compounds tentatively identified on the basis of geologic and geochemical data as diapregnane and diahomopregnane, rearranged isomers of pregnane and homopregnane with methyl substitution at the 5- and 14-carbon positions. The distribution of these compounds parallels that of the higher molecular weight diasteranes. A well-defined relationship is evident between the ratio Fe/S and short-chain diasterane content: samples with Fe/S approximately <0.90 exhibit low diasterane contents, while those with Fe/S approximately >0.90 exhibit high diasterane content. This threshold Fe/S value is nearly equal to the value associated with stoichiometric pyrite (0.87) and suggests that the abundance of short-chain diasteranes is related to excess iron associated with detrital clays. This is consistent with the accepted mechanism of sterane rearrangement, which is thought to proceed via catalysis of clay minerals. In contrast to the higher molecular-weight diasteranes, which increase in abundance relative to other sterane isomers with increasing thermal maturation, the abundance of the rearranged short-chain compounds varies little relative to diginane or homodiginane in a maturity suite from the U. Devonian Duvernay Formation. 38 refs., 11 figs., 3 tabs.

  4. Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C{sub 1}-C{sub 4}) and dimethyl carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroyuki, E-mail: matsuda@chem.cst.nihon-u.ac.jp [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Fukano, Makoto; Kikkawa, Shinichiro [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Constantinescu, Dana [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany); Kurihara, Kiyofumi; Tochigi, Katsumi; Ochi, Kenji [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Gmehling, Juergen [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany)

    2012-01-15

    Highlights: > The VLE behavior of systems containing dimethyl carbonate (DMC) was investigated. > VLE data for ternary and binary mixtures containing alcohol and DMC were measured. > Several activity coefficient models were used for data reduction or prediction. > Valley line, i.e., distillation boundary, was observed for the ternary mixture. > Residue curves were calculated to investigate composition profile for distillation. - Abstract: (Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {l_brace}methanol + propan-1-ol + dimethyl carbonate (DMC){r_brace}, and four binary mixtures, namely an {l_brace}alcohol (C{sub 3} or C{sub 4}) + DMC{r_brace}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich-Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor-liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.

  5. Levels of C{sub 10}-C{sub 13} polychloro-n-alkanes in marine mammals from the Arctic and the St. Lawrence River estuary

    Energy Technology Data Exchange (ETDEWEB)

    Tomy, G.T.; Muir, D.C.G.; Stern, G.A.; Westmore, J.B.

    2000-05-01

    Marine mammals from various regions of the Arctic and the St. Lawrence River estuary were examined for the first time for levels of C{sub 10}--C{sub 13} polychloro-n-alkanes (sPCAs). Respective mean total sPCA concentrations in the blubber of beluga whales (Delphinapterus leucas) from Saqqaq and Nuussuaq, western Greenland, were 0.23 {+-} 0.02 (n = 2) and 0.164 {+-} 0.06 {micro}g/g (n = 2), similar to that in beluga from the Mackenzie Delta in the western Canadian Arctic 0.21 {+-} 0.08 {micro}g/g (m = 3). sPCAs levels were higher in beluga blubber from the St. Lawrence River (0.37 to 1.4 {micro}g/g). Mean sPCA concentrations in the blubber samples from walruses (Odobenus rosmarus) (Thule, northwest Greenland) and ringed seal (Phoca hispida) (Eureka, southwest Ellesmere Island) were 0.43 {+-} 0.06 (n = 2) and 0.53 {+-} 0.2 {micro}g/g (n = 6), respectively. Relative to commercial sPCA formulations, samples from the Arctic marine mammals showed a predominance of the shorter chain length lower percent chlorinated PCA congeners, the more volatile components of industrial formulations. This observation is consistent with long-range atmospheric transport of sPCAs to this region. The profiles of the belugas from the St. Lawrence River estuary, however, had higher proportions of the less volatile sPCA congeners, implying that contamination to this region is probably from local sources.

  6. Design, synthesis, and biological evaluation of novel dipeptide-type SARS-CoV 3CL protease inhibitors: structure-activity relationship study.

    Science.gov (United States)

    Thanigaimalai, Pillaiyar; Konno, Sho; Yamamoto, Takehito; Koiwai, Yuji; Taguchi, Akihiro; Takayama, Kentaro; Yakushiji, Fumika; Akaji, Kenichi; Kiso, Yoshiaki; Kawasaki, Yuko; Chen, Shen-En; Naser-Tavakolian, Aurash; Schön, Arne; Freire, Ernesto; Hayashi, Yoshio

    2013-07-01

    This work describes the design, synthesis, and evaluation of low-molecular weight peptidic SARS-CoV 3CL protease inhibitors. The inhibitors were designed based on the potent tripeptidic Z-Val-Leu-Ala(pyrrolidone-3-yl)-2-benzothiazole (8; Ki = 4.1 nM), in which the P3 valine unit was substituted with a variety of distinct moieties. The resulting series of dipeptide-type inhibitors displayed moderate to good inhibitory activities against 3CL(pro). In particular, compounds 26m and 26n exhibited good inhibitory activities with Ki values of 0.39 and 0.33 μM, respectively. These low-molecular weight compounds are attractive leads for the further development of potent peptidomimetic inhibitors with pharmaceutical profiles. Docking studies were performed to model the binding interaction of the compound 26m with the SARS-CoV 3CL protease. The preliminary SAR study of the peptidomimetic compounds with potent inhibitory activities revealed several structural features that boosted the inhibitory activity: (i) a benzothiazole warhead at the S1' position, (ii) a γ-lactam unit at the S1-position, (iii) an appropriately hydrophobic leucine moiety at the S2-position, and (iv) a hydrogen bond between the N-arylglycine unit and a backbone hydrogen bond donor at the S3-position. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. Preparation & characterization of SiO{sub 2} interface layer by dip coating technique on carbon fibre for C{sub f}/SiC composites

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Kundan, E-mail: kundanemails@gmail.com [Fusion Reactor Material Development & Characterization Division, Institute for Plasma Research, GIDC Electronics Estate, Sector-25, Gandhinagar-382016 (India); Centre for Nanotechnology, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi-835205 INDIA (India); Jariwala, C., E-mail: chetan@ipr.res.in; Pillai, R.; Chauhan, N.; Raole, P. M. [Fusion Reactor Material Development & Characterization Division, Institute for Plasma Research, GIDC Electronics Estate, Sector-25, Gandhinagar-382016 (India)

    2015-08-28

    Carbon fibres (C{sub f}) are one of the most important reinforced materials for ceramic matrix composites such as C{sub f} - SiC composites and they are generally sought for high temperature applications in as space application, nuclear reactor and automobile industries. But the major problem arise when C{sub f} reinforced composites exposed to high temperature in an oxidizing environment, C{sub f} react with oxygen and burnt away. In present work, we have studied the effect of silica (SiO{sub 2}) coating as a protective coating on C{sub f} for the C{sub f} / SiC composites. The silica solution prepared by the sol-gel process and coating on C{sub f} is done by dip coating technique with varying the withdrawing speed i.e. 2, 5, 8 mm/s with fixed dipping cycle (3 Nos.). The uniform silica coating on the C{sub f} is shown by the Scanning Electron Microscope (SEM) analysis. The tensile test shows the increase in tensile strength with respect to increase in withdrawing speed. The isothermal oxidation analysis confirmed enhancement of oxidation resistance of silica coated C{sub f} as compared tothe uncoated C{sub f}.

  8. Fullerene C{sub 70} decorated TiO{sub 2} nanowires for visible-light-responsive photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Er-Chieh [Department of Clinical Pharmacy, School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 110, Taiwan (China); Ciou, Jing-Hao [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Zheng, Jia-Huei; Pan, Job [Department of Clinical Pharmacy, School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 110, Taiwan (China); Hsiao, Yu-Sheng, E-mail: yshsiao@mail.mcut.edu.tw [Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China); Lee, Kuen-Chan, E-mail: kclee@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Huang, Jen-Hsien, E-mail: 295604@cpc.com.tw [Department of Green Material Technology, Green Technology Research Institute, CPC Corporation, Kaohsiung 30010, Taiwan (China)

    2015-11-15

    Graphical abstract: - Highlights: • TiO{sub 2} nanowire decorated with C{sub 60} and C{sub 70} derivatives has been synthesized. • The fullerenes impede the charge recombination due to its high electron affinity. • The fullerenes expand the utilization of solar light from UV to visible light. • The modified-TiO{sub 2} has great biocompatibility. - Abstract: In this study, we have synthesized C{sub 60} and C{sub 70}-modified TiO{sub 2} nanowire (NW) through interfacial chemical bonding. The results indicate that the fullerenes (C{sub 60} and C{sub 70} derivatives) can act as sinks for photogenerated electrons in TiO{sub 2}, while the fullerene/TiO{sub 2} is illuminated under ultraviolet (UV) light. Therefore, in comparison to the pure TiO{sub 2} NWs, the modified TiO{sub 2} NWs display a higher photocatalytic activity under UV irradiation. Moreover, the fullerenes also can function as a sensitizer to TiO{sub 2} which expand the utilization of solar light from UV to visible light. The results reveal that the C{sub 70}/TiO{sub 2} NWs show a significant photocatalytic activity for degradation of methylene blue (MB) in visible light region. To better understand the mechanism responsible for the effect of fullerenes on the photocatalytic properties of TiO{sub 2}, the electron only devices and photoelectrochemical cells based on fullerenes/TiO{sub 2} are also fabricated and evaluated.

  9. C-Cl activation by group IV metal oxides in solid argon matrixes: matrix isolation infrared spectroscopy and theoretical investigations of the reactions of MOx (M = Ti, Zr; x = 1, 2) with CH3Cl.

    Science.gov (United States)

    Zhao, Yanying

    2013-07-11

    Reactions of the ground-state titanium and zirconium monoxide and dioxide molecules with monochloromethane in excess argon matrixes have been investigated in solid argon by infrared absorption spectroscopy and density functional theoretical calculations. The results show that the ground-state MOx (M = Ti, Zr; x = 1, 2) molecules react with CH3Cl to first form the weakly bound MO(CH3Cl) and MO2(CH3Cl) complexes. The MO(CH3Cl) complexes can rearrange to the CH3M(O)Cl isomers with the Cl atom of CH3Cl coordination to the metal center of MO upon UV light irradiation (λ MOx mechanism was interpreted by the calculated potential energy profiles.

  10. [Bi3GaS5]2[Ga3Cl10]2[GaCl4]2·S8 containing heterocubane-type [Bi3GaS5]2+, star-shaped [Ga3Cl10]-, monomeric [GaCl4]- and crown-like S8.

    Science.gov (United States)

    Freudenmann, Dominic; Feldmann, Claus

    2011-01-14

    By reaction of elemental bismuth, sulfur, bismuth(III) chloride and gallium(III) chloride in the ionic liquid (BMIm)Cl (BMIm: 1-butyl-3-methylimidazolium), [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is obtained as red transparent crystals. According to X-ray structure analysis based on single crystals, the title compound crystallizes with triclinic lattice symmetry and is composed of heterocubane-type [Bi(3)GaS(5)](2+) cations, trimeric star-shaped [Ga(3)Cl(10)](-) anions with three (GaCl(4)) tetrahedra sharing a single central chlorine atom, monomeric [GaCl(4)](-) tetrahedra and neutral, crown-shaped S(8)-rings. Here, the heterocubane [Bi(3)GaS(5)](2+) as well as the star-shaped [Ga(3)Cl(10)](-) are observed as building units for the first time. [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is further characterized by X-ray powder diffraction as well as by thermogravimetry/differential thermal analysis.

  11. Mechanical properties and electronic structures of M{sub 23}C{sub 6} (M = Fe, Cr, Mn)-type multicomponent carbides

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yangzhen [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 (China); State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an, Shaanxi, 710049 (China); Jiang, Yehua, E-mail: jiangyehua@kmust.edu.cn [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 (China); Xing, Jiandong [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an, Shaanxi, 710049 (China); Zhou, Rong [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 (China); Feng, Jing, E-mail: jfeng@seas.harvard.edu [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093 (China); School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02318 (United States)

    2015-11-05

    The mechanical and electronic properties of M{sub 23}C{sub 6}- (M = Fe, Cr, Mn) and M{sub 23}C{sub 6}-type multicomponent carbides are investigated systematically by first-principles calculations. The values of cohesive energy and formation enthalpy exhibited thermodynamically stable structures of these carbides. The stress–strain method and Voigt-Reuss-Hill approximation were used to calculate the elastic constants and moduli, respectively. The mechanical properties of the doped Fe or Mo in M{sub 23}C{sub 6} compounds are superior to the pure phases of Cr{sub 23}C{sub 6}, Mn{sub 23}C{sub 6} and Fe{sub 23}C{sub 6}. Mechanical anisotropy of these compounds was illustrated from the anisotropic index and different shapes of the surface contour by Young's modulus. Moreover, the total density of states of M{sub 23}C{sub 6} compounds indicated that the bonding behaviors of M{sub 23}C{sub 6} compounds were combinations of metallic and covalent bonds. - Graphical abstract: The crystal structure of M{sub 23}C{sub 6} (M = Cr, Mn, Fe, Mo, W), which formed in different heat treatment of many iron-based alloys can dramatically influence the mechanical properties of materials such as extreme hardness, high melting point, wear resistance, corrosion resistance and high thermal conductivity, etc. - Highlights: • The mechanical properties of M{sub 23}C{sub 6} (M = Fe, Cr, Mn) multicomponent carbides are estimated. • The anisotropy of M{sub 23}C{sub 6} carbides are discussed with regards to bonding and density of states. • M{sub 23}C{sub 6} (M = Fe, Cr, Mn) multicomponent carbides are thermodynamically stable.

  12. Bulk plasma fragmentation in a C{sub 4}F{sub 8} inductively coupled plasma: A hybrid modeling study

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shu-Xia; Zhang, Yu-Ru [School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China); Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium); Gao, Fei; Wang, You-Nian [School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China); Bogaerts, Annemie [Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium)

    2015-06-28

    A hybrid model is used to investigate the fragmentation of C{sub 4}F{sub 8} inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. C{sub x}F{sub y} (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C{sub 4}F{sub 8} inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C{sub 4}F{sub 8} reaction set used in the model. The C{sub 4}F{sub 8} plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model.

  13. Molecular simulation of C{sub 60} adsorption onto a TiO{sub 2} rutile (1 1 0) surface

    Energy Technology Data Exchange (ETDEWEB)

    Palace Carvalho, A.J., E-mail: ajpalace@uevora.pt [Centro de Quimica de Evora, Universidade de Evora, R. Romao Ramalho 59, 7000-671 Evora (Portugal); Departamento de Quimica, Universidade de Evora, R. Romao Ramalho 59, 7000-671 Evora (Portugal); Prates Ramalho, J.P. [Centro de Quimica de Evora, Universidade de Evora, R. Romao Ramalho 59, 7000-671 Evora (Portugal); Departamento de Quimica, Universidade de Evora, R. Romao Ramalho 59, 7000-671 Evora (Portugal)

    2010-06-15

    A Monte Carlo molecular simulation study is presented on the adsorption and growth of C{sub 60} films on the surface of the (1 1 0) face of rutile. Simulations are performed for a temperature of 600 K using atomistic models both for the fullerene molecules and the TiO{sub 2} surface. It is found in this work that C{sub 60} is adsorbed preferably in an ordered arrangement along the surface depressions over the exposed undercoordinated Ti cations. At low densities adsorption occurs preferably at alternate rows, with locations in consecutive rows being occupied appreciably only at higher C{sub 60} densities. At low densities, the fullerene molecules tend to aggregate into islands in the surface plane. Additional layers of C{sub 60} form only as the density increases, and do so before a monolayer is completed in all consecutive rows. Full monolayer capacity obtained at the highest densities is about 0.9 C{sub 60} molecules per nm{sup 2}, but this is only achieved by completing the packing of molecules in interstices at a slightly upper level. The fraction of the molecules that lie closest to the surface only amounts to 0.6 molecules per nm{sup 2}.

  14. Static disorder in hexagonal crystal structures of C{sub 60} at 100 K and 20 K

    Energy Technology Data Exchange (ETDEWEB)

    Ramm, M. [Freie Univ. Berlin (Germany). Inst. fuer Kristallographie]|[Technische Fachhochschule Berlin (Germany)]|[University of the Witwatersrand, Johannesburg (South Africa); Luger, P. [Freie Univ. Berlin (Germany). Inst. fuer Kristallographie]|[Technische Fachhochschule Berlin (Germany)]|[University of the Witwatersrand, Johannesburg (South Africa); Zobel, D. [Freie Univ. Berlin (Germany). Inst. fuer Kristallographie]|[Technische Fachhochschule Berlin (Germany)]|[University of the Witwatersrand, Johannesburg (South Africa); Duczek, W. [Freie Univ. Berlin (Germany). Inst. fuer Kristallographie]|[Technische Fachhochschule Berlin (Germany)]|[University of the Witwatersrand, Johannesburg (South Africa); Boeyens, J.C.A. [Freie Univ. Berlin (Germany). Inst. fuer Kristallographie]|[Technische Fachhochschule Berlin (Germany)]|[University of the Witwatersrand, Johannesburg (South Africa)

    1996-04-01

    C{sub 60} .2 C{sub 8}H{sub 10} (100 K): hexagonal space group P6{sub 3}, a = 23.694(4), c = 10.046(2) A, V = 4884(2) A{sup 3}, D{sub x} = 1.903 g cm{sup -3}, Z = 6, F(000) = 2856, {lambda}(CuK{alpha}) = 1.54178 A, {mu} = 0.84 mm{sup -1}. C{sub 60} . 2 C{sub 8}H{sub 10} (20 K): hexagonal space group P6{sub 3}, a = 23.67(1), c = 10.02(1) A, V = 4862(6) A{sup 3}, D{sub x} = 1.912 g cm{sup -3}, Z = 6, F(000) = 2856, {lambda}(CuK{alpha}) = 1.54178 A, {mu} = 0.84 mm{sup -1}. The structures were determined by Patterson syntheses and rigid-body refinements. The C{sub 60} molecules show two orientations with one molecular centre in common. The solvent molecules are disordered too. Static disorder could not be overcome or influenced by cooling down. A coordination number of 10 was found for the fullerene molecules. (orig.)

  15. Electronic excitation induced modification in fullerene C{sub 70} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Pooja [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Singhal, R., E-mail: rsinghal.phy@mnit.ac.in [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Banerjee, M.K. [Department of Metallurgical & Materials Engineering, Malaviya National Institute of Technology, Jaipur 302017 (India); Vishnoi, R. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Department of Physics, Vardhman - PG College, Bijnor 246701, UP (India); Kaushik, R. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Department of Physics, Shri K.K. Jain - PG College, Khatauli, UP (India); Singh, F. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2016-07-15

    Fullerene C{sub 70} thin films were deposited by resistive heating on glass substrates and the thickness were approximated to be 150 nm. The effect of energy deposition by 55 MeV Si ions on the optical and structural properties of the prepared thin film samples is investigated. The samples were irradiated with 55 MeV Si ions within fluence range from 1 × 10{sup 12} to 3 × 10{sup 13} ions/cm{sup 2}. For optical studies, the pristine and the Si ion irradiated samples are examined by UV–visible absorption spectroscopy and Raman spectroscopy. UV–visible absorption studies reveal that the absorption peaks of irradiated samples decrease with a decrease in the band gap of the thin films. The damage cross-section (σ) and radius of damaged cylindrical zone (r) are determined as ∼0.6 × 10{sup −13} cm{sup 2} and ∼1.41 nm, respectively from the Raman spectra. Raman studies also suggest that at higher fluence (up to 3 × 10{sup 13} ions/cm{sup 2}), the damage caused by the SHI results in partial amorphization of fullerene C{sub 70} thin film. Modification in the surface properties has been investigated by atomic force microscopy; it has revealed that the roughness decreases and average particle size increases with the increase in fluences.

  16. Creation and destruction of C{sub 60} and other fullerene solids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Huffman, D.R.

    1996-06-05

    The 1990 announcement of the Huffman-Kratschmer fullerene-production technique set off a world-wide explosion of research into the properties and potential applications of C{sub 60} and C{sub 70}. In the last five years, 4,000+ fullerene articles have appeared in the scientific literature dealing with these fascinating molecules and their condensed phases. They possess a complex chemistry reminiscent of the alkenes, and this has led to the syntheses of numerous new compounds and fullerene-based materials, with suggested applications ranging from medicine to photo-conducting polymers to rocket fuel. The work summarized in this report focused on the creation and destruction of fullerene-based materials, for the purpose of producing new materials of interest. This three year project was supported by a grant from the Advanced Energy Projects Division, Office of Basic Energy Sciences, U.S. Department of Energy (DE-FG03-93ER12133). Following are outlines of the work completed in each of the three years, a section devoted to the professional and educational development of those involved, a brief section on the outlook for fullerene-based materials, and an appendix listing the publications resulting from this project.

  17. Perturbation-facilitated detection of the first quintet-quintet band in C{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Bornhauser, P.; Knopp, G.; Beck, M.; Gerber, T.; Radi, P. P., E-mail: peter.radi@psi.ch [Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Marquardt, R.; Gourlaouen, C. [Laboratoire de Chimie Quantique, Institut de Chimie, Université de Strasbourg. 4, rue Blaise Pascal - CS90032 67081 STRASBOURG CEDEX (France); Bokhoven, J. A. van [Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Institute for Chemical and Bioengineering, ETHZ, Zürich (Switzerland)

    2015-03-07

    The first high-spin transition in C{sub 2} (1 {sup 5}Π{sub u} − 1 {sup 5}Π{sub g}) is observed by perturbation-facilitated optical-optical double resonance spectroscopy. The experiment is performed by applying unfolded two-color resonant four-wave mixing. C{sub 2} radicals in the initial a {sup 3}Π{sub u}, v = 5 state are produced by using a discharge source in a molecular beam environment. The final quintet state is excited via intermediate “gateway” states exhibiting both substantial triplet and quintet character due to a perturbation between the 1 {sup 5}Π{sub g}, v = 0 and the d {sup 3}Π{sub g}, v = 6 states. Fifty seven rotational transitions in the P, Q, and R branches of all spin sub-states are measured and yield accurate molecular constants of the newly found upper level 1 {sup 5}Π{sub u}. In addition, satellite transitions (ΔJ ≠ ΔN) are observed and allow an accurate determination of the spin-orbit constant. The results are compared with high-level ab initio computations at the multi-reference configuration interaction level of theory. The high-lying quintet state is found to be predissociative and displays a shallow potential that accommodates three vibrational levels only.

  18. CXCR4(+) CD45(-) Cells are Niche Forming for Osteoclastogenesis via the SDF-1, CXCL7, and CX3CL1 Signaling Pathways in Bone Marrow.

    Science.gov (United States)

    Goto, Yoh; Aoyama, Mineyoshi; Sekiya, Takeo; Kakita, Hiroki; Waguri-Nagaya, Yuko; Miyazawa, Ken; Asai, Kiyofumi; Goto, Shigemi

    2016-06-24

    Bone homeostasis comprises the balance between bone-forming osteoblasts and bone-resorbing osteoclasts (OCs), with an acceleration of osteoclastic bone resorption leading to osteoporosis. OCs can be generated from bone marrow cells (BMCs) under the tightly regulated local bone environment. However, it remained difficult to identify the critical cells responsible for providing an osteoclastogenesis niche. In this study, we used a fluorescence-activated cell sorting technique to determine the cell populations important for forming an appropriate microenvironment for osteoclastogenesis and to verify the associated interactions between osteoclast precursor cells and non-OCs. We isolated and removed a small cell population specific for osteoclastogenesis (CXCR4(+) CD45(-) ) from mouse BMCs and cultured the remaining cells with receptor activator of nuclear factor-kappa B ligand (RANKL) and macrophage-colony stimulating factor. The resulting cultures showed significantly less large osteoclast formation. Quantitative RT-PCR analysis revealed that these CXCR4(+) CD45(-) cells expressed low levels of RANK and RANKL, but high levels of critical chemokines including stromal cell derived factor 1 (SDF-1), chemokine (C-X-C motif) ligand 7 (CXCL7), and chemokine (C-X3-C motif) ligand 1 (CX3CL1). Furthermore, an SDF-1-specific antibody strongly suppressed OC formation in RAW264.7 cells and antibodies against SDF-1, CXCL7, and CX3CL1 suppressed OC formation in BMCs. These results suggest that isolated CXCR4(+) CD45(-) cells support an appropriate microenvironment for osteoclastogenesis with a direct effect on the cells expressing SDF-1, CXCL7, and CX3CL1 receptors. The regulation of CXCR4(+) CD45(-) cell function might therefore inform therapeutic strategies for diseases involving loss of bone homeostasis. Stem Cells 2016.

  19. Structural basis for the development of SARS 3CL protease inhibitors from a peptide mimic to an aza-decaline scaffold.

    Science.gov (United States)

    Teruya, Kenta; Hattori, Yasunao; Shimamoto, Yasuhiro; Kobayashi, Kazuya; Sanjoh, Akira; Nakagawa, Atsushi; Yamashita, Eiki; Akaji, Kenichi

    2016-11-04

    Design of inhibitors against severe acute respiratory syndrome (SARS) chymotrypsin-like protease (3CL(pro) ) is a potentially important approach to fight against SARS. We have developed several synthetic inhibitors by structure-based drug design. In this report, we reveal two crystal structures of SARS 3CL(pro) complexed with two new inhibitors based on our previous work. These structures combined with six crystal structures complexed with a series of related ligands reported by us are collectively analyzed. To these eight complexes, the structural basis for inhibitor binding was analyzed by the COMBINE method, which is a chemometrical analysis optimized for the protein-ligand complex. The analysis revealed that the first two latent variables gave a cumulative contribution ratio of r(2)  = 0.971. Interestingly, scores using the second latent variables for each complex were strongly correlated with root mean square deviations (RMSDs) of side-chain heavy atoms of Met(49) from those of the intact crystal structure of SARS-3CL(pro) (r = 0.77) enlarging the S2 pocket. The substantial contribution of this side chain (∼10%) for the explanation of pIC50 s was dependent on stereochemistry and the chemical structure of the ligand adapted to the S2 pocket of the protease. Thus, starting from a substrate mimic inhibitor, a design for a central scaffold for a low molecular weight inhibitor was evaluated to develop a further potent inhibitor. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 391-403, 2016.

  20. Heat of Mixing and Solution of 1,1,1-Trichloroethane C2H3Cl3 + C6H10O Cyclohexanone (HMSD1111, LB3664_H)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'heat of Mixing and Solution of 1,1,1-Trichloroethane C2H3Cl3 + C6H10O Cyclohexanone (HMSD1111, LB3664_H)' providing data from direct low-pressure calorimetric measurement of molar excess enthalpy at variable mole fraction and constant temperature.

  1. Heat of Mixing and Solution of 1,1,2-Trichloroethane C2H3Cl3 + C6H10O Cyclohexanone (HMSD1111, LB3665_H)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'heat of Mixing and Solution of 1,1,2-Trichloroethane C2H3Cl3 + C6H10O Cyclohexanone (HMSD1111, LB3665_H)' providing data from direct low-pressure calorimetric measurement of molar excess enthalpy at variable mole fraction and constant temperature.

  2. Low-temperature heat capacities of crystalline Ho(Gly)_3Cl_3·3H_2O from 78 to 348 K

    Institute of Scientific and Technical Information of China (English)

    张景楠; 王辉; 谭志诚; 刘北平; 史全; 童波

    2009-01-01

    Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temperature range,the heat capacities increased in a smooth and continuous manner and no phase transition or thermal anomaly occurred.Therefore,the sample was stable in the above temperature range.The values of experimental heat capacities were fitted to a polynomial equation with least square method and ...

  3. Propensities toward C{sub 2}H({ital {tilde A}} {sup 2}{Pi}) in acetylene photodissociation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.; Riehn, C.W.; Dulligan, M.; Wittig, C. [Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482 (United States)

    1995-10-15

    When expansion-cooled acetylene is excited to the {nu}{sup {double_prime}}{sub 1}+3{nu}{sup {double_prime}}{sub 3} vibrational level (4 quanta of CH-stretch) and then photodissociated at 248.3 nm, the dominant product channel is C{sub 2}H({ital {tilde A}} {sup 2}{Pi}). This differs markedly from one-photon 193.3 nm photodissociation, which provides 1200 cm{sup {minus}1} less energy and yields C{sub 2}H({ital {tilde X}} {sup 2}{Sigma}{sup +}) as the primary product. Photodissociation at 121.6 nm yields C{sub 2}H({ital {tilde A}} {sup 2}{Pi}) exclusively. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  4. Graphitic Csub>3sub>Nsub>4sub> as a new saturable absorber for the mid-infrared spectral range.

    Science.gov (United States)

    Fan, Mingqi; Li, Tao; Li, Guiqiu; Ma, Houyi; Zhao, Shengzhi; Yang, Kejian; Kränkel, Christian

    2017-01-15

    The saturable absorption properties of few-layer graphitic carbon nitride (g-Csub>3sub>Nsub>4sub>) nanosheets near 3 μm were investigated. A stable Q-switched Er:Lusub>2sub>Osub>3sub> laser at 2.84 μm was realized by using a home-made g-Csub>3sub>Nsub>4sub> saturable absorber (SA), generating a pulse duration of 351 ns and an average output power of 1.09 W at a repetition rate of 99 kHz, corresponding to a pulse energy of 11.1 μJ. Our result indicates a great potential of g-Csub>3sub>Nsub>4sub> as a new SA in the 3 μm wavelength range.

  5. Cytotoxicity and photocytotoxicity of structure-defined water-soluble C{sub 60}/micelle supramolecular nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Metanawin, Tanapak; Tang Tian; Chen Rongjun; Wang Xiaosong [School of Chemistry, University of Leeds, LS2 9TJ (United Kingdom); Vernon, David, E-mail: X.S.Wang@leeds.ac.uk [School of Biological Sciences, University of Leeds, LS2 9TJ (United Kingdom)

    2011-06-10

    Well-defined, water-soluble C{sub 60}/micelle hierarchical colloids with varied amounts of C{sub 60} sitting on the surface of micellar cores were prepared via the self-assembly of PS-b-PDMA block copolymer micelles and C{sub 60}. The composites can generate a significant amount of reactive oxygen upon irradiation with red light. Cell studies showed that the colloids were either strongly associated with, or internalized by, the cells after 2 h incubation, but did not show obvious toxicity in the dark. In contrast, efficient cell killing was observed when the colloid-incubated cells were exposed to red light. This indicates that the supramolecular colloids are promising as photosensitizers for photodynamic cancer therapy.

  6. Synergistic induction of CX3CL1 by TNF alpha and IFN gamma in osteoblasts from rheumatoid arthritis: involvement of NF-kappa B and STAT-1 signaling pathways

    Directory of Open Access Journals (Sweden)

    Kuninobu Wakabayashi

    2008-10-01

    Full Text Available Takeo Isozaki, Tsuyoshi Kasama, Ryo Takahashi, Tsuyoshi Odai, Kuninobu Wakabayashi, Hirohito Kanemitsu, Kyoko Nohtomi, Hiroko T Takeuchi, Satoshi Matsukura, Masakazu TezukaDivision of Rheumatology, Department of Internal Medicine, Showa University School of Medicine, Tokyo, Japan, and the Department of Orthopedics, Denencyofu Central Hospital, Tokyo, JapanAbstract: To explore the regulation of CX3CL1 in inflammatory bone diseases, CX3CL1 expression by osteoblasts (OB was examined. Human OB isolated from rheumatoid arthritis (RA patients, osteoarthritis patients, and normal individuals were incubated in the presence of cytokines. Soluble CX3CL1 levels were determined with an enzyme-linked immunosorbent assay. Expression of CX3CL1 mRNA was examined using quantitative real-time polymerase chain reaction. Although tumor necrosis factor (TNF-α or interferon (IFN-γ alone RA OB induced negligible CX3CL1 secretion, the combination of TNF-α and IFN-γ induced dramatic increases in both soluble CX3CL1 protein and mRNA transcripts. This synergistic effect was more pronounced in OB from RA than in OB from either osteoarthritis or normal individuals. The expression of CX3CL1 was markedly reduced by specific inhibitors of the nuclear factor-κB (NF-κB or STAT-1 transcription factor. These findings suggest that osteoblasts are an important cellular source of CX3CL1 and may play roles in inflammatory bone/joint diseases.Keywords: osteoblast, CX3CL1, chemokine, NF-κB, STAT-1

  7. Perturbative determination of c{sub sw} for plaquette and Symanzik gauge action and stout link clover fermions

    Energy Technology Data Exchange (ETDEWEB)

    Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics; Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division, Dept. of Mathematical Sicences; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2008-06-15

    Using plaquette and Symanzik improved gauge action and stout link clover fermions we determine the improvement coefficient c{sub SW} in one-loop lattice perturbation theory from the off-shell quark-quark-gluon three-point function. In addition, we compute the coefficients needed for the most general form of quark field improvement and present the one-loop result for the critical hopping parameter {kappa}{sub c}. We discuss mean field improvement for c{sub SW} and {kappa}{sub c} and the choice of the mean field coupling for the actions we have considered. (orig.)

  8. Synthesis and characterization of Zr{sub 2}Al{sub 3}C{sub 4} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Chung-Chuan, E-mail: chula@ifm.liu.se; Tucker, Mark D.; Lu, Jun; Jensen, Jens; Greczynski, Grzegorz; Eklund, Per; Rosen, Johanna

    2015-11-30

    Zr{sub 2}Al{sub 3}C{sub 4} is an inherently nanolaminated carbide where layers of ZrC alternate with layers of Al{sub 3}C{sub 2}. Characterization of bulk samples has shown it has improved damage tolerance and oxidation resistance compared to its binary counterpart ZrC. Though a potential candidate for coatings applied for use in harsh environments, thin films of Zr{sub 2}Al{sub 3}C{sub 4} have not been reported. We have synthesized epitaxial Zr{sub 2}Al{sub 3}C{sub 4} thin films by pulsed cathodic arc deposition from three elemental cathodes, and have studied the effect of incident atomic flux ratio, deposition temperature, and choice of substrate on material quality. X-ray diffraction analysis showed that Zr{sub 2}Al{sub 3}C{sub 4} of the highest structural quality was obtained for growth on 4 H–SiC(001) substrate at 800 °C. Also, suppression of competing phases could be achieved on α-Al{sub 2}O{sub 3}(001) at elevated substrate temperatures. Very similar growth behavior to that of the well-known M{sub n+1}AX{sub n} phases – Al supersaturation, binary carbide intergrowth and high sensitivity to choice of substrate – indicates a strong connection between the two families of materials, despite their differences in structure and in chemistry. - Highlights: • Nearly phase pure epitaxial Zr{sub 2}Al{sub 3}C{sub 4} thin films were grown on 4 H–SiC(001) substrates. • Intergrowth of ZrC phase can be observed when Al is deficient during growth. • Suppression of competing phases can be achieved by increasing temperature on Al{sub 2}O{sub 3}(001). • Substrate selectivity of Zr{sub 2}Al{sub 3}C{sub 4} phase is explained by lattice mismatch and substrate quality. • Very similar growth behavior to the known MAX phases were observed for Zr{sub 2}Al{sub 3}C{sub 4}.

  9. Cluster effect on projected range of 30 keV C{sub 60}{sup +} in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Y.; Nakajima, K.; Suzuki, M. [Department of Micro Engineering, Kyoto University, Kyoto 606-8501 (Japan); Narumi, K.; Saitoh, Y. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gumma 370-1292 (Japan); Vandervorst, W. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Kimura, K., E-mail: kimura@kues.kyoto-u.ac.jp [Department of Micro Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2011-10-01

    Pre-amorphized silicon wafers are implanted with 30 keV C{sub 60}{sup +} and 0.5 keV C{sup +} ions at room temperature with fluences about 2 x 10{sup 15} atoms/cm{sup 2}. The depth profiles of implanted carbon are measured using high-resolution Rutherford backscattering spectroscopy. The observed average depth of C for the C{sub 60}{sup +} implantation is 6.1 nm while that for the C{sup +} implantation is 4.0 nm, showing a large cluster effect on the projected range.

  10. A facile synthesis of C{sub 60}-organosilicon hybrid polymers: Considering their tunable optical properties for spin-on-silicon hardmask materials

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin-Kyu; Dao, Tung Duy; Kim, Ye-Seul; Jeong, Hyun-Dam, E-mail: hdjeong@chonnam.ac.kr

    2016-09-15

    Organic-inorganic hybrid materials with high refractive index have attracted considerable attention for many optoelectronic applications, including spin-on-type hardmask for ArF lithography (193 nm). In this study, we demonstrate the synthesis of a C{sub 60}-embedded organosilicon hybrid polymer, C{sub 60}-embedded poly-xylene-hexamethyltrisiloxane hybrid (C{sub 60}-PXS), of tunable optical properties. C{sub 60} was covalently bonded to the PXS backbone through Pt-catalyzed hydrosilylation, in which the PXS was formed possibly by unexpected transition metal-catalyzed benzylic C−H silylation and oxygenation of the o-xylene. The C{sub 60}-PXS thin films fabricated using a spin-coating method showed much higher refractive index by 5–22% according to the curing temperatures, than the PXS thin films containing no C{sub 60}. In particular, the C{sub 60}-PXS thin film cured at 350 °C showed the refractive index (n) and extinction coefficient (k) at 193 nm to be 1.61 and 0.29 that are very close to the optimum values for the Si-hardmask. This implies the high applicability of the C{sub 60}-embedded organosilicon hybrid polymer, C{sub 60}-PXS, for the spin-on Si-hardmask in ArF lithography. - Highlights: • A facile synthetic route for C{sub 60}-embedded organosilicon hybrid polymer was presented. • The hybrid polymer showed much higher refractive index than the polymer without C{sub 60}. • The hybrid polymer is highly applicable for Si-hardmask in terms of optical properties. • It is believed that the properties of the hybrid polymer can be further optimized.

  11. Microglial CX3CR1 promotes adult neurogenesis by inhibiting Sirt 1/p65 signaling independent of CX3CL1.

    Science.gov (United States)

    Sellner, Sabine; Paricio-Montesinos, Ricardo; Spieß, Alena; Masuch, Annette; Erny, Daniel; Harsan, Laura A; Elverfeldt, Dominik V; Schwabenland, Marius; Biber, Knut; Staszewski, Ori; Lira, Sergio; Jung, Steffen; Prinz, Marco; Blank, Thomas

    2016-09-17

    Homo and heterozygote cx3cr1 mutant mice, which harbor a green fluorescent protein (EGFP) in their cx3cr1 loci, represent a widely used animal model to study microglia and peripheral myeloid cells. Here we report that microglia in the dentate gyrus (DG) of cx3cr1 (-/-) mice displayed elevated microglial sirtuin 1 (SIRT1) expression levels and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) p65 activation, despite unaltered morphology when compared to cx3cr1 (+/-) or cx3cr1 (+/+) controls. This phenotype was restricted to the DG and accompanied by reduced adult neurogenesis in cx3cr1 (-/-) mice. Remarkably, adult neurogenesis was not affected by the lack of the CX3CR1-ligand, fractalkine (CX3CL1). Mechanistically, pharmacological activation of SIRT1 improved adult neurogenesis in the DG together with an enhanced performance of cx3cr1 (-/-) mice in a hippocampus-dependent learning and memory task. The reverse condition was induced when SIRT1 was inhibited in cx3cr1 (-/-) mice, causing reduced adult neurogenesis and lowered hippocampal cognitive abilities. In conclusion, our data indicate that deletion of CX3CR1 from microglia under resting conditions modifies brain areas with elevated cellular turnover independent of CX3CL1.

  12. Synthesis, crystal structure, and photoelectric properties of Re(CO)(3)ClL (L = 2-(1-ethylbenzimidazol-2-yl)pyridine).

    Science.gov (United States)

    Wang, Kezhi; Huang, Ling; Gao, Lihua; Jin, Linpei; Huang, Chunhui

    2002-07-01

    A novel Re(I) complex, Re(CO)(3)ClL (L = 2-(1-ethylbenzimidazol-2-yl)pyridine), has been synthesized and structurally characterized by single-crystal X-ray diffraction analysis. Crystal data for C(17)H(13)ClN(3)O(3)Re: space group, orthorhombic, Pbca; a = 12.713(6) A; b = 15.103(7) A; c = 18.253(8) A; Z = 8. Stable vacuum vapor deposition of the Re complex has been verified by UV-vis and infrared spectroscopy. A two-layer electroluminescent device with configuration of ITO/TPD/Re(CO)(3)ClL/Mg(0.9)Ag(0.1)/Ag has been fabricated, which gave a turn-on voltage of as low as 3 V and a maximum luminance of 113 cd/m(2) at a bias voltage of 10.5 V, and confirmed that the Re complex can function as a bright orange-red emitter and an electron transport material in an electroluminescent device.

  13. Pb remobilization by bacterially mediated dissolution of pyromorphite Pb5(PO4)3Cl in presence of phosphate-solubilizing Pseudomonas putida.

    Science.gov (United States)

    Topolska, Justyna; Latowski, Dariusz; Kaschabek, Stefan; Manecki, Maciej; Merkel, Broder J; Rakovan, John

    2014-01-01

    Remediation of lead (Pb)-contaminated sites with phosphate amendments is one of the best studied and cost-effective methods for in situ immobilization. In this treatment, a very stable mineral, pyromorphite Pb5(PO4)3Cl, is formed. Several studies propose to improve this treatment method with the addition of phosphate-solubilizing bacteria (PSB). The effect of bacteria on solubilization of pyromorphite is unknown. In this study, the effect of the soil microorganisms on the stability of pyromorphite Pb5(PO4)3Cl has been investigated in a set of batch solution experiments. The mineral was reacted with Pseudomonas putida, a common soil microorganism. Dissolution of pyromorphite was enhanced by the presence of P. putida, resulting in an elevated Pb concentration in the solution. This occurred even when the bacteria were provided with an additional source of phosphate in the solution. Pyromorphite has been shown to be a potential source of nutrient phosphorus for common soil bacteria. Thus, the use of PSB in remediation treatments of Pb contaminated sites may have adverse long-term impacts on Pb immobilization. Conscious phosphate management is suggested for long-term sustainability of the in situ Pb immobilization by pyromorphite formation.

  14. Raman and Mid-IR Spectral Analysis of the Atacamite-Structure Hydroxyl/Deuteroxyl Nickel Chlorides Ni2(OH/D)3Cl

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Dong; Hagihala Masato; ZHENG Xu-Guang; MENG Dong-Doug; GUO Qi-Xin

    2011-01-01

    @@ Vibrational spectra(Raman 4000-95cm-1 and mid-IR 4000-400cm-1) of the atacamite-structure Ni2(OH)3Cl,including a rarely reported kind of asymmetric trimetric hydrogen bond, as a member of the geometrically frustrated material series and its deuteride Ni2(OD)3Cl are, to the best of our knowledge, reported for the first time and analyzed at room temperature.Through a comparative study of four spectra according to their crystal structural parameters, we assign OH stretching modes v(OH) in a functional group region(3700-3400 cm-1) and their deformation modes δ(NiOH/D) in the correlation peak region(900-600 cm-1)with the corresponding mode frequency ratios ωv(OD)/ωv(OH)≈73% and ωδ(NiOD)/ωδ(NiOH)≈75%, and further self-consistently suggest NiO and Ni-Cl related modes in the fingerprint region(500-200cm-1 and 200-Ocm-1, respectively) by use of the unified six-ligand NiO5Cl and NiO4Cl2 frames.This report may contribute to the spectral analysis of other hydroxyl transition-metal halides and to the understanding of the fundamental physics of their exotic magnetic geometrical frustration property from the spectral changes around the corresponding low transition temperatures.

  15. Responses of the C[sub 4] grass Schizachyrium and grassland invader Prosopis over glacial to present CO[sub 2] concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Polley, H.W.; Johnson, H.B.; Mayeux, H.S. (USDA-ARS, Temple, TX (United States))

    1993-06-01

    The woody C[sub 3] Prosopis glandulosa and perennial C[sub 4] grass Schizachyrium scoparium were grown along a daytime gradient from 340 to 200 [mu]mol/mol CO[sub 2] to determine effects of the increase in atmospheric [CO[sub 2

  16. Plasmon excitations in C{sub 60} by fast charged particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Li, C. Z. [College of Physics and Electronic Information, Inner Mongolia University for the Nationalities, Tongliao 028043 (China); Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Miskovic, Z. L. [Department of Applied Mathematics and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Goodman, F. O. [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Wang, Y. N. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China)

    2013-05-14

    For an isolated C{sub 60} molecule, we study plasmon excitations that are induced by an external, fast moving electron, by using a two-dimensional, spherical, two-fluid hydrodynamic model for the dynamic response of the {sigma} and {pi} electrons in the carbon nanostructure. Second quantization of the linearized hydrodynamic model allows us to discuss how effective is multiple excitation of various plasmon modes. Mean numbers of the excited plasmon modes, differential cross sections, and the total energy loss of the incident electron are calculated by both a quantized model with zero damping and by a semi-classical model with phenomenological damping. Our calculated differential cross sections are compared with experiment.

  17. Modeling buckminsterfullerene spinning in (C{sub 60}){sub n} clusters

    Energy Technology Data Exchange (ETDEWEB)

    Deleuze, M.S. [Limburgs Universitair Centrum, Diepenbeek (Belgium); Zerbetto, F. [Univ. degli Studi di Bologna (Italy)

    1999-06-09

    Temperature-dependent rate constants for the spinning of buckminsterfullerene in (C{sub 60}){sub n} clusters (n = 3--13) are calculated using unimolecular reaction rate theory with parameters obtained from molecular mechanics simulations. The lowest lying intracluster rotations tend to spread over several cages toward the surface and the edges of the clusters. Coaxial rotations appear also in this regime. A simple argument is put forward to justify the use of harmonic spacing in the study of the dynamics of these degrees of freedom. The increase in the size of the cluster makes the calculated rate constants converge toward the value reported in the solid. The satisfactory result of this simple form of kinetic theory implies that the energy of the internal degrees of freedom is randomized sufficiently fast with respect to the spinning coordinates.

  18. Reactive organic air components (C{sub 6}-C{sub 12}) of anthropogenic and biogenic origin in deciduous and coniferous forests. Final report; Reaktive organische Luftkomponenten (C{sub 6}-C{sub 12}) anthropogenen und biogenen Ursprungs in Laub- und Nadelwaeldern. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Steinbrecher, R.; Fehsenfeld, U.; Hauff, K.; Jocher, M.; Kolb, C.; Reichmann, A.; Steinbrecher, J.; Tranos, S.; Wiedemann, M.

    1996-08-01

    Biogenic hydrocarbons are known to act as important precursors in tropospheric photochemical ozone formation. Large uncertainties exist about the composition of the mix of volatile organic compounds, emitted by various plant species and the respective emission rates. The emission and deposition behavior of C{sub 6} to C{sub 12} volatile organic compounds (VOC) in Norway spruce forests, oak/pine forests, grassland and the Mediterranean Garigue were studied in detail. The cuvette technique was used to study the emission form the soil, trunks and twigs. The gradient method and the REA-technique were used to obtain canopy fluxes. Among the investigated ecosystems, forests and the Mediterranean Garigue were strong monoterpene emitters, grassland emitted negligible amounts of VOC. Tall forests may act as a sink for anthropogenic hydrocarbons. In a dense Norway spruce forests the contribution of the soil to the total canopy emission was small, the fraction of the steam region may range from 1 to 64% and is not clear yet. For the upper suncrown, with ca. 80% of the needle surfaces the most important source for isoprene and monoterpenes of a closed canopy, a emission factor for {alpha}-pinene of 636 pmol m{sup -2} total needle surface s{sup -1} (30 C leaf temperature and 1000 {mu}E PAR) was calculated. In contrast to the general opinion the main controlling factors of the {alpha}-pinene emission from Norway spruce twigs and the monoterpene emission from Mediterranean oaks are light and temperature. The results of this research were used to update biogenic VOC emission inventories and a significant improvement was achieved. (orig.) [Deutsch] Biogene Kohlenwasserstoffe sind wichtige Vorlaeufer fuer die photochemische Ozonbildung in der Troposphaere. Ueber die qualitative Zusammensetzung der Emissionen von fluechtigen organischen Verbindungen aus der Vegetation und die Quellenstaerken der verschiedenen Verbindungen bestehen grosse Unsicherheiten. In Fichtenwaeldern, Kiefern

  19. Paths, tableaux and q-characters of quantum affine algebras: the C{sub n} case

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, Wakako; Nakanishi, Tomoki [Graduate School of Mathematics, Nagoya University, Nagoya 464-8602 (Japan)

    2006-03-03

    For the quantum affine algebra U{sub q}(g-circumflex) with g of classical type, let {chi}{sub {lambda}}{sub /{mu}}{sub ,a} be the Jacobi-Trudi-type determinant for the generating series of the (supposed) q-characters of the fundamental representations. We conjecture that {chi}{sub {lambda}}{sub /{mu}}{sub ,a} is the q-character of a certain finite-dimensional representation of U{sub q}(g-circumflex). We study the tableaux description of {chi}{sub {lambda}}{sub /{mu}}{sub ,a} using the path method due to Gessel-Viennot. It immediately reproduces the tableau rule by Bazhanov-Reshetikhin for A{sub n} and by Kuniba-Ohta-Suzuki for B{sub n}. For C{sub n}, we derive the explicit tableau rule for skew diagrams {lambda}/{mu} of three rows and of two columns.

  20. Ca10(Si2O7)3Cl2:Eu2+Mn2+单-基质白光荧光粉的发光性质%Luminescence Properties of single host White Phosphor Ca10(Si2O7)3Cl2: Eu2+Mn2+:

    Institute of Scientific and Technical Information of China (English)

    杨志平; 赵方亮; 李盼来; 路亚娟; 李小宁

    2009-01-01

    用高温固相法合成了颜色可调的Ca10(Si2O7)3Cl2:Eu2+Mn2+荧光粉.研究了它的发光性质和Eu2+与Mn2+之间的能量传递.Eu2+离子在Ca10(Si2O7)3Cl2晶体中形成了峰值为426 nm和523 nm的5d→4f跃迁发光,Eu2+中心向Mn2+中心传递能量,敏化Mn2+离子4T1(4G)-6A1(6S)跃迁而产生585 nm的黄光发射.黄绿蓝3个发射带叠加在单一基质中实现了白光发射.3个发射带的激发谱范围位于250-480 nm处,Ca10(Si2O7)3Cl2:Eu2+Mn2+在紫外-近紫外波段(350~410 nm)范围内有很强的激发,是一种适合InGaN管芯激发的单一基质白光LED荧光粉.

  1. Effect of Cr on electronic and magnetic properties of χ-carbide (Fe,Cr){sub 5}C{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Wang, B. [State Key Laboratory of Metastable Material Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Zhang, Q.; Zhang, Z.F. [College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004 (China); Lv, Z.Q., E-mail: zqlv@ysu.edu.cn [College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004 (China); Fu, W.T. [State Key Laboratory of Metastable Material Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

    2015-10-15

    From density-function theory calculation, the structural, electronic and magnetic properties of χ-carbides (Fe,Cr){sub 5}C{sub 2} are investigated. With the increase of Cr content in χ-carbides (Fe,Cr){sub 5}C{sub 2}, the formation energy of χ carbide gradually decrease and energy stability of them increase. The formation energy of Cr{sub 5}C{sub 2} is −0.354 eV/f.u, and the stability of Cr{sub 5}C{sub 2} is higher than other χ carbides (Fe,Cr){sub 5}C{sub 2}, Mn{sub 5}C{sub 2} and Fe{sub 5}C{sub 2}. There exists charges transfer from metal cation (Fe/Cr) to C atoms in χ-carbides, and this reveals an ionic contribution to the bonds. The addition of Cr decreases the magnetic moments of χ carbide, and the magnetic moments (Ms) of Cr{sub 2}Cr{sub 2}FeC{sub 2} and Cr{sub 5}C{sub 2} are 0 μ{sub B}/f.u., while it expresses opposite magnetic characters of the same atom at different sites in the other χ type (Fe,Cr){sub 5}C{sub 2} carbides. The 3d states of metal atoms in the majority states (up) move to above the Femi level and some metal atoms (Fe/Cr) in χ type (Fe,Cr){sub 5}C{sub 2} are undergone the anti-ferromagnetic transformation. - Highlights: • Energy stability of (Fe,Cr){sub 5}C{sub 2} increase with Cr, and the formation energy of Cr{sub 5}C{sub 2} is −0.354 eV/f.u. • Magnetic characters of the same atom at different sites in some χ (Fe,Cr){sub 5}C{sub 2} carbides are opposite. • Some metal atoms in χ (Fe,Cr){sub 5}C{sub 2} are undergone the anti-ferromagnetic transformation.

  2. Production of anti-fullerene C{sub 60} polyclonal antibodies and study of their interaction with a conjugated form of fullerene

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, O. D., E-mail: odhendrick@gmail.com; Fedyunina, N. S. [Russian Academy of Sciences, Institute of Biochemistry (Russian Federation); Martianov, A. A. [Moscow State University (Russian Federation); Zherdev, A. V.; Dzantiev, B. B. [Russian Academy of Sciences, Institute of Biochemistry (Russian Federation)

    2011-09-15

    The aim of this study was to produce anti-fullerene C{sub 60} antibodies for the development of detection systems for fullerene C{sub 60} derivatives. To produce anti-fullerene C{sub 60} antibodies, conjugates of the fullerene C{sub 60} carboxylic derivative with thyroglobulin, soybean trypsin inhibitor, and bovine serum albumin were synthesized by carbodiimide activation and characterized. Immunization of rabbits by the conjugates led to the production of polyclonal anti-fullerene antibodies. The specificity of the immune response to fullerene was investigated. Indirect competitive immunoenzyme assay was developed for the determination of conjugated fullerene with detection limits of 0.04 ng/mL (calculated for coupled C{sub 60}) and 0.4 ng/mL (accordingly to total fullerene-protein concentration).

  3. Rotationally relaxed, grating tuned laser oscillations in optically pumped C/sub 2/D/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, T.A.; Wittig, C.

    1982-07-15

    Rotationally relaxed, grating tuned laser oscillations are obtained in the frequency range 500--562 cm/sup -1/ via the optical pumping of C/sub 2/D/sub 2//He mixtures with a transverse, electric, atmospheric (TEA) CO/sub 2/ laser. Strong Q-branch oscillations at 530.8 cm/sup -1/ are also reported.

  4. A combined crossed molecular beams and theoretical study of the reaction CN + C{sub 2}H{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Balucani, Nadia, E-mail: nadia.balucani@unipg.it [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Leonori, Francesca; Petrucci, Raffaele [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Wang, Xingan [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Casavecchia, Piergiorgio [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Skouteris, Dimitrios [Scuola Normale Superiore, Pisa (Italy); Albernaz, Alessandra F. [Instituto de Física, Universidade de Brasília, Brasília (Brazil); Gargano, Ricardo [Instituto de Física, Universidade de Brasília, Brasília (Brazil); Departments of Chemistry and Physics, University of Florida, Quantum Theory Project, Gainesville, FL 32611 (United States)

    2015-03-01

    Highlights: • The CN + C{sub 2}H{sub 4} reaction was investigated in crossed beam experiments. • Electronic structure calculations of the potential energy surface were performed. • RRKM estimates qualitatively reproduce the experimental C{sub 2}H{sub 3}NC yield. - Abstract: The CN + C{sub 2}H{sub 4} reaction has been investigated experimentally, in crossed molecular beam (CMB) experiments at the collision energy of 33.4 kJ/mol, and theoretically, by electronic structure calculations of the relevant potential energy surface and Rice–Ramsperger–Kassel–Marcus (RRKM) estimates of the product branching ratio. Differently from previous CMB experiments at lower collision energies, but similarly to a high energy study, we have some indication that a second reaction channel is open at this collision energy, the characteristics of which are consistent with the channel leading to CH{sub 2}CHNC + H. The RRKM estimates using M06L electronic structure calculations qualitatively support the experimental observation of C{sub 2}H{sub 3}NC formation at this and at the higher collision energy of 42.7 kJ/mol of previous experiments.

  5. Effect of fiber surface state on mechanical properties of C{sub f}/Si-O-C composites

    Energy Technology Data Exchange (ETDEWEB)

    Wang Song [Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China)]. E-mail: wangsong0731@163.com; Chen Zhaohui [Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China); Ma Qingsong [Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China); Hu Haifeng [Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China); Zheng Wenwei [Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China)

    2005-10-25

    Three-dimensional braided carbon fiber reinforced silicon oxycarbide composites (3D-B C{sub f}/Si-O-C) were fabricated via a polysiloxane infiltration and pyrolysis route. The effects of fiber surface state on microstructure and mechanical properties of C{sub f}/Si-O-C composites were investigated. The change of carbon fiber surface state was achieved via heat treatment in vacuum. The results showed that heat treatment decreased carbon fiber surface activity due to the decrease of the amount of oxygen and nitrogen atoms. The C{sub f}/Si-O-C composites fabricated from the carbon fiber with low surface activity had excellent mechanical properties, which resulted from perfect interfacial bonding and good in situ fiber strength. The flexural strength and fracture toughness of the C{sub f}/Si-O-C composites from the treated fiber were 534 MPa and 23.4 MPa m{sup 1/2}, respectively, which were about 7 and 11 times more than those of the composites from the as-received carbon fiber, respectively.

  6. Sputtering of thin benzene and polystyrene overlayers by keV Ga and C{sub 60} bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Czerwinski, B. [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, Cracow 30-059 (Poland); Delcorte, A. [PCPM, Universite Catholique de Louvain, Croix du Sud 1, B-1348 Louvain-la-Neuve (Belgium); Garrison, B.J. [104 Chemistry Building, Department of Chemistry, Penn State University, University Park, PA 16802 (United States); Samson, R. [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, Cracow 30-059 (Poland); Winograd, N. [104 Chemistry Building, Department of Chemistry, Penn State University, University Park, PA 16802 (United States); Postawa, Z. [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, Cracow 30-059 (Poland)]. E-mail: zp@castor.if.uj.edu.pl

    2006-07-30

    The mechanisms of ion-stimulated desorption of thin organic overlayers deposited on metal substrates by mono- and polyatomic projectiles are examined using molecular dynamics (MD) computer simulations. A monolayer of polystyrene tetramers (PS4) physisorbed on Ag{l_brace}1 1 1{r_brace} is irradiated by 15 keV Ga and C{sub 60} projectiles at normal incidence. The results are compared with the data obtained for a benzene overlayer to investigate the differences in sputtering mechanisms of weakly and strongly bound organic molecules. The results indicate that the sputtering yield decreases with the increase of the binding energy and the average kinetic energy of parent molecules is shifted toward higher kinetic energy. Although the total sputtering yield of organic material is larger for 15 keV C{sub 60}, the impact of this projectile leads to a significant fragmentation of ejected species. As a result, the yield of the intact molecules is comparable for C{sub 60} and Ga projectiles. Our data indicate that chemical analysis of the very thin organic films performed by detection of sputtered neutrals will not benefit from the use of C{sub 60} projectiles.

  7. Wear behavior of SiC, Cr{sub 3}C{sub 2} and WC doped alumina

    Energy Technology Data Exchange (ETDEWEB)

    Mindivan, H.; Cimenoglu, H.; Kayali, E.S. [Istanbul Technical Univ., Dept. of Metallurgy and Materials Engineering, Istanbul (Turkey); Bakan, H.I. [Tubitak, MAM, Gebze-Kocaeli (Turkey)

    2004-07-01

    In this study, the wear behavior of the pure and carbide (SiC, Cr{sub 3}C{sub 2}, and WC) doped alumina was investigated. Carbide doping increased the hardness and improved the wear resistance, significantly. WC doped alumina exhibited the highest hardness and wear resistance. (orig.)

  8. Synthesis and thermal stability of two-dimensional carbide MXene Ti{sub 3}C{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhengyang; Wang, Libo; Sun, Dandan; Zhang, Yude; Liu, Baozhong; Hu, Qianku; Zhou, Aiguo, E-mail: zhouag@hpu.edu.cn

    2015-01-15

    Graphical abstract: - Highlights: • Ti{sub 3}C{sub 2} from PLS-Ti{sub 3}AlC{sub 2} was highly oriented compared to that from HP-Ti{sub 3}AlC{sub 2}. • Small balls of possible AlF{sub 3} attached on the edge of MXene sheets were observed. • MXene is thermally stable in Ar atmosphere up to 800 °C. • A structure of nano-anatase on 2D Ti{sub 3}C{sub 2} was formed by 200 °C oxidization. - Abstract: We investigated the synthesis of quasi-two-dimensional carbide (Ti{sub 3}C{sub 2}), with the name of MXene, by immersing Ti{sub 3}AlC{sub 2} in 40% or 49% hydrofluoric acid (HF) at 0 °C, 15 °C or 60 °C. The influences of time, temperature, and source of Ti{sub 3}AlC{sub 2} on the synthesis were researched. It was found that Ti{sub 3}C{sub 2} synthesized from pressureless synthesized Ti{sub 3}AlC{sub 2} was highly oriented compared to that from hot-pressed Ti{sub 3}AlC{sub 2}. As-synthesized Ti{sub 3}C{sub 2} could be further exfoliated by intercalation with urea, dimethylsulfoxide or ammonia. From the results of thermogravimetry and differential scanning calorimetry, Ti{sub 3}C{sub 2} MXene with F/OH termination was found to be stable in argon atmosphere at temperature up to 800 °C. In oxygen atmosphere, at 200 °C, parts of MXene layers were oxidized to obtain an interesting structure: anatase nano-crystals were evenly distributed on 2D Ti{sub 3}C{sub 2} layers. At 1000 °C, MXene layers were completely oxidized and anatase phase fully transformed to rutile in oxygen atmosphere.

  9. Increasing CO[sub 2]: Comparative responses of the C[sub 4] grass Schizachyrium and grassland invader Prosopis

    Energy Technology Data Exchange (ETDEWEB)

    Polley, H.W.; Johnson, H.B.; Mayeux, H.S. (Department of Agriculture, Temple, TX (United States))

    1994-06-01

    Woody C[sub 3] Prosopis glandulosa (honey mesquite) and C[sub 4] perennial grass Schizachyrium scoparium (little bluestem) were grown along a gradient of daytime carbon dioxide concentrations from near 340 to 200 [mu]mol/mol air in a 38 m long controlled environment chamber. The authors studied the effects of historical and prehistorical increases in atmospheric CO[sub 2] concentration on growth, resource use, and competitive interactions of a species representative of C[sub 4]-dominated grasslands in the SW United States and the invasive legume P. glandulosa. Increasing CO[sub 2] concentration stimulated N[sub 2] fixation by individually grown P. glandulosa and elicited in C[sub 3] seedlings a similar relative increase in leaf intercellular CO[sub 2] concentration, net assimilation rate, and intrinsic water use efficiency (leaf net assimilation rate/stomatal conductance). Aboveground biomass of P. glandulosa was not altered by CO[sub 2] concentration, but belowground biomass and whole-plant water and nitrogen use efficiencies increased linearly with CO[sub 2] concentration in seedlings that were grown alone. Biomass produced by P. glandulosa that was grown with S. scoparium was not affected by CO[sub 2] concentration. Stomatal conductance declined and leaf assimilation rates of S. scoparium at near maximum incident light increased at higher CO[sub 2] concentration, but there was no effect of CO[sub 2] concentration on biomass production or whole-plant water use efficiency of the C[sub 4] grass. Rising CO[sub 2] concentration, especially the 27% increase since the beginning of the 19th century, may have contributed to more abundant P. glandulosa on C[sub 4] grasslands by stimulating the shrub's growth or reducing the amount of resources that the C[sub 3] required. Much of the potential response of P. glandulosa to CO[sub 2] concentration, however, appears to be contingent on the shrub's escaping competition with neighboring grasses. 62 refs., 10 figs., 1

  10. Exploring the Reactivity of Na[W2(μ-Cl3Cl4(THF2]∙(THF3 towards the Polymerization of Selected Cycloolefins

    Directory of Open Access Journals (Sweden)

    Nikolaos Saragas

    2015-12-01

    Full Text Available The bimetallic compound Na[W2(μ-Cl3Cl4(THF2]·(THF3 (1, {W 3 W}6+, a′2e′4 is a highly efficient room-temperature initiator for ring opening metathesis polymerization (ROMP of norbornene (NBE and some of its derivatives. In most cases, addition of phenylacetylene (PA as co-initiator improves the catalytic activity and retains the high cis-stereoselectivity. On the other hand, 1 can polymerize cyclopentadiene (CPD, not via a metathetic, but rather, via a cationic mechanism. Here, we present a comparison of the reactivity of the two catalytic systems (1 and 1/PA between themselves and with other systems reported in the literature, the characterization of the polymers formed and mechanistic aspects of the corresponding reactions.

  11. Magnetic susceptibility and Mössbauer studies of [FeX3](ClO4)2.H2O with X = bpz, bpy, phen or tpy

    Science.gov (United States)

    Ho, J. C.; Hamdeh, H. H.; Kirgan, R.; Rillema, D. P.

    2008-03-01

    Magnetic studies have been made on several tris-chelated iron complex compounds [FeX3](ClO4)2.H2O with aromatic nitrogen heterocycle ligands X = bpz (2,2'-bipyrazine), bpy (2,2'-bipyridine), phen (1,10-phenanthroline) or tpy (2,2':6,2''-terpyridine). SQUID data (2-300 K and 0.01-1 T) yielded small effective magnetic moments, which are characteristic of low-spin Fe(II), in agreement with the isomer shift and quadrupole splitting values from Mössbauer measurements (4-300 K, 0-5 T). Meanwhile, apart from the expected diamagnetism, a positive term of temperature-independent paramagnetic susceptibility prevails in most cases.

  12. PbCl2-tuned inorganic cubic CsPbBr3(Cl) perovskite solar cells with enhanced electron lifetime, diffusion length and photovoltaic performance

    Science.gov (United States)

    Li, Bo; Zhang, Yanan; Zhang, Luyuan; Yin, Longwei

    2017-08-01

    Inorganic CsPbBr3 perovskite is arousing great interest following after organic-inorganic hybrid halide perovskites, and is found as a good candidate for photovoltaic devices for its prominent photoelectric property and stability. Herein, we for the first time report on PbCl2-tuned inorganic Cl-doped CsPbBr3(Cl) perovskite solar cells with adjustable crystal structure and Cl doping for enhanced carrier lifetime, extraction rate and photovoltaic performance. The effect of PbCl2 on the morphologies, structures, optical, and photovoltaic performance of CsPbBr3 perovskite solar cells is investigated systemically. Compared with orthorhombic CsPbBr3, cubic CsPbBr3 demonstrates a significant improvement for electron lifetime (from 6.7 ns to 12.3 ns) and diffusion length (from 69 nm to 197 nm), as well as the enhanced electron extraction rate from CsPbBr3 to TiO2. More importantly, Cl doping benefits the further enhancement of carrier lifetime (14.3 ns) and diffusion length (208 nm). The Cl doped cubic CsPbBr3(Cl) perovskite solar cell exhibits a Jsc of 8.47 mA cm-2 and a PCE of 6.21%, superior to that of pure orthorhombic CsPbBr3 (6.22 mA cm-2 and 3.78%). The improvement of photovoltaic performance can be attributed to enhanced carrier lifetime, diffusion length and extraction rates, as well as suppressed nonradiative recombination.

  13. A new method for As(V) removal from waters by precipitation of mimetite Pb5(AsO4)3Cl on Pb-activated zeolite

    Science.gov (United States)

    Manecki, Maciej; Buszkiewicz, Urszula

    2016-04-01

    A new method for removal of arsenate AsO43- ions from aqueous solutions is proposed. The principle of the method stems from precipitation of very insoluble crystalline lead arsenate apatite (mimetite Pb5(AsO4)3Cl) induced by bringing in contact Pb-activated zeolite and As-contaminated water in the presence of Cl-. Zeolite is activated by sorption of Pb2+ followed by washing with water to remove the excess of Pb and to desorbe weakly adsorbed ions. Lead adsorbed on zeolite is bound strong enough to prevent desorption by water but weak enough to undergo desorption induced by heterogeneous precipitation of mimetite nanocrystals on the surface of zeolite. The experiment consisted of two steps. In the first step, aliquots of 0.5 g of natural clinoptilolite zeolite (from Zeocem a.s., Bystré, Slovak Republic) were reacted with 40 mL of solutions containing 20, 100, 500, and 2000 mg Pb/L (pH =4.5; reaction for 30 minutes followed by centrifugation). The amount of Pb sorbed was calculated from the drop of Pb concentration in solution. Centrifuged zeolite was washed three times by mixing with 10 mL of DDI water, followed by centrifugation. No Pb was detected in the water after second washing. Wet pulp resulting from this stage was exposed to solutions containing 70 mg/L Cl- and various concentrations of AsO43- (2 and 100 mg As/L; pH=4). Complete removal of As was observed for 2 mg As/L solutions mixed with zeolite-20 and zeolite-100. The precipitation of mimetite Pb5(AsO4)3Cl in the form of hexagonal crystals ca. 0.25 μm in size was observed using SEM/EDS. This work is partially funded by AGH research grant no 11.11.140.319.

  14. Nido-Carborane building-block reagents. 2. Bulky-substituent (alkyl)/sub 2/C/sub 2/B/sub 4/H/sub 6/ derivatives and (C/sub 6/H/sub 5/)/sub 2/C/sub 2/B/sub 4/H/sub 6/: synthesis and properties

    Energy Technology Data Exchange (ETDEWEB)

    Boyter, H.A. Jr.; Grimes, R.N.

    1988-09-07

    The preparation and chemistry of nido-2,3-R/sub 2/C/sub 2/C/sub 2/B/sub 4/H/sub 6/ carboranes in which R is n-butyl, isopentyl, n-hexyl, and phenyl was investigated in order to further assess the steric and electronic influence of the R groups on the properties of the nido-C/sub 2/B/sub 4/ cage, especially with respect to metal complexation at the C/sub 2/B/sub 3/ face and metal-promoted oxidative fusion. The three dialkyl derivatives were prepared from the corresponding dialkylacetylenes via reaction with B/sub 5/H/sub 9/ and triethylamine, but the diphenyl compound could not be prepared in this manner and was obtained instead in a thermal reaction of B/sub 5/H/sub 9/ with diphenylacetylene in the absence of amine. All four carboranes are readily bridge-deprotonated by NaH in THF, and the anions of the dialkyl species, on treatment with FeCl/sub 2/ and air oxidation, generate the respective R/sub 4/C/sub 4/B/sub 8/H/sub 8/ carborane fusion products were R = n-C/sub 4/H/sub 9/, i-C/sub 5/H/sub 11/ or n-C/sub 6/H/sub 13/. The diphenylcarborane anion Ph/sub 2/C/sub 2/B/sub 4/H/sub 5//sup /minus// did not form detectable metal complexes with Fe/sup 2+/, Co/sup 2+/, or Ni/sup 2+/, and no evidence of a Ph/sub 4/C/sub 4/B/sub 8/H/sub 8/ fusion product has been found. Treatment of Ph/sub 2/C/sub 2/B/sub 4/H/sub 6/ with Cr(CO)/sub 6/ did not lead to metal coordination of the phenyl rings, unlike (PhCH/sub 2/)/sub 2/C/sub 2/B/sub 4/H/sub 6/, which had previously been shown to form mono- and bis(tricarbonylchromium) complexes. However, the reaction of Ph/sub 2/C/sub 2/B/sub 4/H/sub 5//sup /minus//, CoCl/sub 2/, and (PhPCH/sub 2/)/sub 2/ did give 1,1-(Ph/sub 2/PCH/sub 2/)/sub 2/-1-Cl-1,2,3-Co(Ph/sub 2/C/sub 2/B/sub 4/H/sub 4/), the only case in which metal complexation of the diphenylcarborane was observed. 14 references, 3 figures, 3 tables.

  15. 白光LED用单一基质Ca10(Si2O7)3Cl2:Eu24,Mn2+白色发光材料特性研究%Luminescence characteristics of the single host white emitting Ca10(Si2O7)3Cl2:Eu2+,Mn2+ phosphor for white LED

    Institute of Scientific and Technical Information of China (English)

    杨志平; 李盼来; 王志军; 郭庆林; 李旭

    2009-01-01

    采用高温固相法制备了单一基质Ca10(Si2O7)3Cl2:Eu2+,Mn2+白色发光材料,研究发现材料适于近紫外光激发,发射高亮度的白色光.Eu2+发射中心形成峰值为426和523 nm的特征宽谱,通过Eu2+向Mn2+的能量传递,形成了峰值为585 nm的宽谱发射;红、绿、蓝三色发射带叠加后,在同一基质中实现了白光发射.利用Dexter电多极相互作用的能量传递公式,得出Ca10(Si2O7)3Cl2中Eu2+对Mn2+的能量传递属于电偶极-电偶极相互作用引起的共振能量传递.利用InGaN管芯(370 nm)激发Ca10(Si2O7)3Cl2:Eu2+,Mn2+材料,获得了很好的白光发射,测得的色坐标为(x=0.323,y=0.327),色温为5664民显色指数为85%.

  16. Luminescence Properties of Bright Ca2SiO3Cl2∶Eu2+ for White LEDs%用于白光LED的高亮度蓝白色荧光粉Ca2SiO3Cl2∶Eu2+的发光性质

    Institute of Scientific and Technical Information of China (English)

    杨志平; 刘玉峰; 李雪清

    2006-01-01

    采用固相法在较低温度下合成了Eu2+激活的Ca2SiO3Cl2高亮度蓝白色发光材料,并对其发光性质进行了研究.其发射光谱由两个谱带组成,峰值分别位于420,498 nm处,归结为Ca2SiO3Cl2晶体中占据两种不同Ca2+格位的Eu2+离子的5d→4f跃迁发射.改变Eu2+浓度,可以使样品的发光在蓝白色和绿白色之间变化.当Eu2+浓度为0.005 mol-1时,样品呈现很亮的蓝白色发光.两个发射峰的激发光谱均分布在250~410nm的波长范围内,峰值分别位于333,369 nm处.Ca2SiO3Cl2∶Eu2+可被InGaN管芯产生的近紫外辐射有效激发,是一种性能良好的白光LED用单一基质蓝白色荧光粉.

  17. Ejecting intact large molecular structures by C{sub 60} ion impact upon bio-organic solids; Ejection de tres grandes structures moleculaires intactes par impact de C{sub 60} sur des solides bioorganiques

    Energy Technology Data Exchange (ETDEWEB)

    Brunelle, A.; Della Negra, S.; Deprun, C.; Depauw, J.; Jacquet, D.; Le Beyec, Y.; Pautrat, N. [Experimental Research Division, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France); Haakansson, P. [Division of Ion Physics, Angstrom Laboratory, Uppsala Univ. Uppsala (Sweden)

    1999-11-01

    C{sub 60} molecules accelerated to MeV energies (20 MeV) have been used to induce the desorption-ionization of large bio-molecules from solid samples. In the case of the trypsin molecules, the secondary molecular ion emission yield is about two orders of magnitude larger than with MeV atomic ions. This is a consequence of the very high energy density deposited in solids by 20 MeV C{sub 60} projectiles that gives rise to a large amount of matter ejected after each impact. Although time-of-flight mass spectra can be recorded within a few seconds, it is more the mechanistic aspects in comparison with other particle induced desorption methods, which are the objective of these first results with energetic fullerenes. (authors) 1 fig.

  18. Bacteria mediated dissolution of pyromorphite Pb5(PO4)3Cl in presence of Pseudomonas putida bacteria - an effect on Pb remobilization in the environment

    Science.gov (United States)

    Flis, Justyna; Manecki, Maciej; Merkel, Broder J.; Latowski, Dariusz

    2010-05-01

    The objective of the study was to determine the mechanisms of microbially enhanced dissolution of lead phosphate-pyromorphite Pb5(PO4)3Cl). Contrary to the current literature, the results of our experiments indicate a great potential for Pb remobilization in the environment by an aerobic microorganism acquiring phosphates. Broad knowledge exists about the role of Pb-apatites in regulating the behavior and the bioavailability of Pb in soils and wastewater. In situ Pb immobilization is one of the methods now routinely applied for the reclamation of Pb-contaminated soils, including shallow unconfined aquifers (Magalhaes & Silva, 2003; Magalhaes, 2002; Ma et al. 1993). This method is based on the principle that aqueous phosphates added to soil pore solutions form a very stable (insoluble) mineral pyromorphite (Pb-apatite) Pb5(PO4)3Cl. Bioavailability of aqueous Pb is thus minimized due to the very low solubility and the high thermodynamic stability of pyromorphite (Flis, 2007; Nriagu, 1974). Several reports have examined the ability of different bacterial species including Pseudomonas to solubilise insoluble inorganic phosphate compounds for example apatites (Welch et al., 2002; Maurice et al., 1999; Rodriguez and Fraga, 1999 ). Various species of Pseudomonas genera are encountered as common inhabitants of soils and wastes in the industrial areas under strong pollution influence. To date, there has not been any published evidence of microbial dissolution of pyromorphite. The major objective of the project was to study Pseudomonas putida growth in the presence of Pb-apatite (Pb5(PO4)3Cl) as the sole source of phosphate. It was to test the hypothesis that in the phosphate deficient environment bacteria are able to actively scavenge for P from the Pb-apatite which results in remobilization of Pb in the environment. The bacteria growth was investigated at 22oC. Commercially available Pseudomonas putida strain was used throughout. The experiment and its controls were run in

  19. Application of the extended real associated solution (ERAS) theory to excess molar enthalpies of benzaldehyde + 1-alkanols (C{sub 1} to C{sub 5}) at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Iloukhani, H., E-mail: iloukhani@basu.ac.ir [Department of Physical Chemistry, Faculty of Chemistry, University of Bu-Ali Sina, Hamedan 65174 (Iran, Islamic Republic of); Fattahi, M. [Department of Physical Chemistry, Faculty of Chemistry, University of Bu-Ali Sina, Hamedan 65174 (Iran, Islamic Republic of)

    2011-11-15

    Highlights: > Enthalpy of binary mixtures of {l_brace}benzaldehyde + 1-alkanols{r_brace} (C{sub 1} to C{sub 5}) determined. > Excess molar enthalpy, partial molar enthalpy, and intermolecular interaction functions were calculated. > Excess molar enthalpy was correlated as a function of mole fraction by using the Redlich-Kister equation. > The experimental results have been used to test the applicability of the ERAS-model, Wilson and NRTL equations. - Abstract: This paper reports excess molar enthalpies, H{sub m}{sup E}, for the binary mixtures of {l_brace}1-alkanols (2), namely, {l_brace}methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol{r_brace} with benzaldehyde (1){r_brace} at T = 298.15 K at ambient pressure over a whole range of mole fraction. The sign of H{sub m}{sup E} for all systems are positive and the magnitude of H{sub m}{sup E} values with increasing of chain length, increase. The Redlich-Kister polynomial equation was used to correlate H{sub m}{sup E}. The excess partial molar enthalpies of benzaldehyde, H{sub m,1}{sup E}, excess partial molar enthalpies of 1-alkanols (C{sub 1} to C{sub 5}), H{sub m,2}{sup E}, and excess partial molar enthalpies at infinite dilution, H{sub m,i}{sup E,0}, are calculated according to experimental excess molar enthalpies and Redlich-Kister polynomial equation. The extracted date were used to evaluated the so-called intermolecular interaction functions {partial_derivative}H{sub m,i}{sup E}/{partial_derivative}x{sub i} and {partial_derivative}H{sub m,i}{sup E}/{partial_derivative}x{sub j} in terms of enthalpy. The ERAS, Wilson and NRTL models have been applied for describing the H{sub m}{sup E}.

  20. Anisometric C>60 Fullerene Colloids Assisted by Structure-Directing Agent

    Energy Technology Data Exchange (ETDEWEB)

    Penterman, S. [Cornell Univ., Ithaca, NY (United States); Liddell Watson, Chekesha M. [Cornell Univ., Ithaca, NY (United States); Escobedo, Fernando A. [Cornell Univ., Ithaca, NY (United States); Cohen, Itai [Cornell Univ., Ithaca, NY (United States)

    2016-08-05

    Colloidal synthesis and assembly provide low cost, large area routes to mesoscale structures. In particular, shape-anisotropic particles may form crystalline, plastic crystalline, complex liquid crystalline and glassy phases. Arrangements in each order class have been used to generate photonic materials. For example, large photonic band gaps have been found for photonic crystals, hyperuniform photonic glasses, and also for plastic crystals at sufficient refractive index contrast. The latter structures support highly isotropic bandgaps that are desirable for free-form waveguides and LED out-coupling. Photonic glasses with optical gain lead to self-tuned lasing by the superposition of multiply scattered light. Typically, extrinsic media such as organic dyes, rare earths, lanthanides and quantum dots are used to impart optical gain in photonic solids. The present work advances fullerene microcrystals as a new materials platform for ‘active’ light emitting in colloid-based photonic crystals. Fullerenes support singlet excited states that recombine to produce a characteristic red photoluminescence. C>60 also has a high refractive index (n ~ 2.2) and transparency (> 560 nm)9 so that inverse structures are not required.

  1. Degradation studies on organic pin solar cells containing ZnPc and C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Hermenau, Martin; Riede, Moritz; Leo, Karl [Institut fuer Angewandte Photophysik, Technische Universitaet Dresden (Germany)

    2009-07-01

    In addition to the power conversion efficiency of organic solar cells, the lifetime of these devices plays an important role for the market entry as commercial products. Therefore a detailed understanding of degradation of organic solar cells is necessary. In this work, we present ageing studies of small-molecule solar cells with a pin structure and a mixed heterojunction of Zinc-Phthalocyanine and fullerene C{sub 60}. These devices have an initial efficiency of 2.8% under solar irradiation. The ageing dynamics of these solar cells are observed under different conditions, e.g. illumination and temperature, and compared to reference devices which are stored in the dark. The external quantum efficiency of these cells is measured before and after ageing studies to observe changes in different spectral ranges. The relative change of external quantum efficiency does not depend on the colour of the incident light during time of ageing, indicating the stability of the absorbing layers during the observed time span.

  2. Second-harmonic generation from C{sub 60} thin films at 1.064 {mu}m

    Energy Technology Data Exchange (ETDEWEB)

    Wilk, D.; Johannsmann, D.; Stanners, C.; Shen, Y.R. [Department of Physics, University of California at Berkeley, Berkeley, California 94720 (United States)

    1995-04-15

    We have performed {ital in} {ital situ} optical second-harmonic-generation measurements using 1.064-{mu}m wavelength laser pulses on C{sub 60} during film growth. We present a complete theoretical description of second-harmonic generation from a thin-film system in terms of surface and bulk contributions as well as local and nonlocal contributions to the optical nonlinearities. The experimental results can be well described in terms of only nonlocal contributions to both surface and bulk nonlinear susceptibilities. We suggest that in our case the second-harmonic-generation process is resonantly enhanced by the {ital h}{sub {ital u}-}{ital t}{sub 1{ital u}} and {ital h}{sub {ital u}-}{ital t}{sub 1{ital g}} transitions in C{sub 60} and that electric-dipole and electric-quadrupole radiations in the output field are comparable in strength.

  3. Cumulants of the three-state Potts model and of nonequilibrium models with C{sub 3v} symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Tome, Tania [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Petri, Alberto [Istituto di Acustica O M Corbino, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, Rome (Italy)

    2002-07-05

    The critical behaviour of two-dimensional stochastic lattice gas models with C{sub 3v} symmetry is analysed. We study the cumulants of the order parameter for the three-state (equilibrium) Potts model and for two irreversible models whose dynamic rules are invariant under the symmetry operations of the point group C{sub 3v}. By means of extensive numerical analysis of the phase transition we show that irreversibility does not affect the critical behaviour of the systems. In particular, we find that the Binder reduced fourth-order cumulant takes a universal value U* which is the same for the three-state Potts model and for the irreversible models. The same universal behaviour is observed for the reduced third-order cumulant. (author)

  4. The carbide M{sub 7}C{sub 3} in low-temperature-carburized austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Frank, E-mail: frank.ernst@cwru.edu [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7204 (United States); Li, Dingqiang; Kahn, Harold; Michal, Gary M.; Heuer, Arthur H. [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7204 (United States)

    2011-04-15

    Prolonged low-temperature gas-phase carburization of AISI 316L-type austenitic stainless steel can cause intragranular precipitation of the carbide M{sub 7}C{sub 3} (M: randomly dispersed Fe, Cr, Ni). Transmission electron microscopy revealed that the carbide particles have the shape of needles. They grow by a ledge-migration mechanism and in a crystallographic orientation relationship to the austenite matrix that enables highly coherent interphase interfaces. A small solubility limit of Ni in the carbide and restricted Ni diffusivity at the processing temperature leads to Ni pileup around the particles and may explain the extreme aspect ratio of the particle shape. These characteristics closely resemble what has been observed earlier for precipitates of M{sub 5}C{sub 2} under slightly different processing conditions and can be rationalized by considering the particular constraints imposed by carburization at low temperature.

  5. Thermal infrared cross-sections of C{sub 2}F{sub 6} at atmospheric temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Q.; Sun, C.; Nemtchinov, V.; Varanasi, P. E-mail: pvaranasi@notes.cc.sunysb.edu

    2004-01-15

    Spectral absorption cross-sections, k{sub {nu}} (cm{sup -1} atm{sup -1}), have been measured in the 8.0 and 8.95 {mu}m bands of C{sub 2}F{sub 6}. Temperature and total (N{sub 2}-broadening) pressure have been varied to represent the conditions specified in various models of the terrestrial atmosphere so that the absorption cross-sections can be applied directly to the optical remote-sensing of C{sub 2}F{sub 6} in the atmosphere. The measured absolute intensities of the 8.0 and the 8.95 {mu}m bands are (1.636{+-}0.003)x10{sup -16} and (0.467{+-}0.0018)x10{sup -16} cm molecule{sup -1}, respectively.

  6. Elaboration, microstructure and reactivity of Cr{sub 3}C{sub 2} powders of different morphology

    Energy Technology Data Exchange (ETDEWEB)

    Loubiere, S.; Laurent, C.; Bonino, J.P.; Rousset, A. [Univ. Paul-Sabatier, Toulouse (France). Lab. de Chimie des Materiaux Inorganiques

    1995-12-01

    Cr{sub 3}C{sub 2} powders have been prepared by heat-treatment of metastable chromium oxides of controlled morphology in H{sub 2}-CH{sub 4} atmosphere. Starting with these highly reactive oxides allows formation of Cr{sub 3}C{sub 2} at 700 C. The reaction is pseudomorphic and different grain shapes (needles, rods, spheres and polyhedra) have been obtained. The size distribution is narrow and the grain size is generally of the order of a few tens of micrometers, bu the spheres are in fact made up of aggregates of small platelets about 1.5 {micro}m wide and 0.7 {micro}m thick. The oxidation in air of the carbides was studied by thermal analyses (TGA, DTG and DSC) and was found to proceed in four steps in the 250--700 C range. The differences observed between the carbides are related to their morphology and texture.

  7. Improvement of depth resolution in XPS analysis of fluorinated layer using C{sub 60} ion sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Nobuta, Takuya, E-mail: takuya_nobuta@gg.nitto.co.jp [Nitto Analytical Techno-Center Co., Ltd., 1-1-2, Shimohozumi, Ibaraki, Osaka 567-8680 (Japan); Ogawa, Toshio [Laboratory for Ecological Polymer Chemistry, Kanazawa Institute of Technology, 7-1, Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)

    2009-12-15

    Depth profile of C{sub 60} ion-used X-ray photoelectron spectroscopy (XPS) was studied on fluorinated organic layers with different thicknesses. We found that the depth resolution decreased, the sputtering rate went down and the surface turned rough as the layer thickness increased. This is because carbon-rich layer was formed on the surface by cross-linking reaction of the polymer and/or accumulation of degraded C{sub 60} through continuous sputtering. Surprisingly, the high sputtering rate drastically improved the resolution of the analysis. The rate over 48.7 nm/min did not show any deterioration on the depth resolution, the sputtering rate and surface smoothness.

  8. Solvent-free functionalization of fullerene C{sub 60} and pristine multi-walled carbon nanotubes with aromatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez-Calera, Itzel J. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510, México, D.F. (Mexico); Meza-Laguna, Victor [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Gromovoy, Taras Yu. [O.O. Chuiko Institute of Surface Chemistry, National Academy of Sciences of the Ukraine, Gen. Naumova 17, 03164 Kiev (Ukraine); Chávez-Uribe, Ma. Isabel [Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Basiuk, Vladimir A., E-mail: basiuk@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Basiuk, Elena V., E-mail: elbg1111@gmail.com [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510, México, D.F. (Mexico)

    2015-02-15

    Highlights: • Pristine multi-walled carbon nanotubes were functionalized with aromatic amines. • The amines add onto nanotube defects, likewise they add onto fullerene C{sub 60}. • The addition takes place at elevated temperature and without organic solvents. • Functionalized nanotubes were characterized by a number of instrumental techniques. - Abstract: We employed a direct one-step solvent-free covalent functionalization of solid fullerene C{sub 60} and pristine multi-walled carbon nanotubes (MWCNTs) with aromatic amines 1-aminopyrene (AP), 2-aminofluorene (AF) and 1,5-diaminonaphthalene (DAN). The reactions were carried out under moderate vacuum, in a wide temperature range of 180–250 °C, during relatively short time of about 2 h. To confirm successful amine attachment, a large number of analytical techniques were used (depending on the nanomaterial functionalized) such as Fourier transform infrared, Raman, X-ray photoelectron, {sup 13}C cross-polarization magic angle spinning NMR spectroscopy, thermogravimetric analysis, laser-desorption ionization time-of-flight mass spectrometry, temperature-programmed desorption with mass spectrometric detection, as well as scanning and transmission electron microscopy. The nucleophilic addition of the aromatic amines to C{sub 60} molecule was studied theoretically by using density functional theory (PBE GGA functional with Grimme dispersion correction in conjunction with the DNP basis set). In the case of crystalline C{sub 60}, the solvent-free technique has a limited applicability due to poor diffusion of vaporous aromatic amines into the bulk. Nevertheless, the approach proposed allows for a facile preparation of aromatic amine-functionalized pristine MWCNTs without contamination with other chemical reagents, detergents and solvents, which is especially important for a vast variety of nanotube applications spanning from nanoelectronics to nanomedicine.

  9. The autoignition of C{sub 8}H{sub 10} aromatics at moderate temperatures and elevated pressures

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Hsi-Ping S.; Oehlschlaeger, Matthew A. [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY (United States)

    2009-05-15

    The autoignition of C{sub 8}H{sub 10} aromatic/air mixtures (ortho-xylene, meta-xylene, para-xylene, and ethylbenzene in air) has been studied in a shock tube at temperatures of 941-1408 K, pressures of 9-45 atm, and equivalence ratios of {phi}=1.0 and 0.5. Ignition times were determined using electronically excited OH emission and pressure measurements. The measurements illustrate the differences in reactivity for the C{sub 8}H{sub 10} aromatics under the studied conditions. Ethylbenzene was by far the most reactive C{sub 8}H{sub 10} aromatic with ignition times a factor of two to three shorter than the xylenes. The xylene isomers exhibited ignition times that were similar, with o-xylene the most reactive, p-xylene the least reactive, and m-xylene just slightly more reactive than p-xylene. The p-xylene ignition times are almost identical to previous measurements for toluene at the same conditions. The differences in reactivity can be attributed to the C-H and C-C bond strengths in the alkyl side chains and the proximity of the methyl groups in the xylenes. These results represent the first ignition measurements for C{sub 8}H{sub 10} aromatics at the elevated-pressure moderate-temperature conditions studied, providing needed targets for kinetic modeling at engine-relevant conditions. Kinetic modeling illustrates the importance of the methylbenzyl + HO{sub 2} reaction and indicates further study of this reaction is warranted. (author)

  10. 用于白光LED的单一基质白光荧光粉Ca2SiO3Cl2:Eu2+,Mn2+的发光性质%Luminesce properties of the single white emitting phosphor Eu2+, Mn2+ co-doped Ca2SiO3Cl2

    Institute of Scientific and Technical Information of China (English)

    杨志平; 刘玉峰; 王利伟; 余泉茂; 熊志军; 徐小岭

    2007-01-01

    用高温固相法合成了Eu2+,Mn2+共激活的Ca2SiO3Cl2高亮度白色发光材料,并对其发光性质进行了研究.该荧光粉在近紫外光激发下发出强的白色荧光,Eu2+中心形成峰值为419 nm和498 nm的特征宽带,通过Eu2+中心向Mn2+中心的能量传递导致了峰值为578 nm的发射,三个谱带叠加从而在单一基质中得到了白光.激发光谱均分布在250-415 nm的波长范围,红绿蓝三个发射带的激发谱峰值分别位于385 nm,412 nm,370 nm和396 nm处,可以被InGaN管芯产生的紫外辐射有效激发.Ca2SiO3Cl2:Eu2+,Mn2+是一种很有前途的单一基质白光LED荧光粉.

  11. Crystal structures and magnetic properties of the honeycomb-lattice antiferromagnet M2(pymca)3(ClO4), (M = Fe, Co, Ni)

    Science.gov (United States)

    Honda, Zentaro; Kodama, Takafumi; Hagiwara, Masayuki; Kida, Takanori; Okutani, Akira; Sakai, Masamichi; Fukuda, Takeshi; Kamata, Norihiko

    2016-09-01

    We report on the syntheses, crystal structures, and magnetic properties of a series of transition metal coordination polymers M2(pymca)3(ClO4), (pymca = pyrimidine-2-carboxylic acid, M = Fe (1), Co (2), and Ni (3)). These compounds are found to crystallize in a trigonal crystal system, space group P31m, with the lattice constants a = 9.727 Å and c = 5.996 Å for 1, a = 9.608 Å and c = 5.996 Å for 2, and a = 9.477 Å and c = 5.958 Å for 3 at room temperature. In these compounds, each pymca ligand connects to two M2+ ions, forming a honeycomb network in the ab plane. The temperature dependences of magnetic susceptibilities in these compounds show broad maxima, indicating antiferromagnetic interactions within two-dimensional honeycomb layers. We also observed an antiferromagnetic phase transition at low temperatures by magnetic susceptibility and heat capacity measurements. From the crystal structures and magnetic properties, we conclude that the compounds 1, 2, and 3 are good realizations of honeycomb-lattice antiferromagnets.

  12. Direct ab initio molecular dynamics study on a microsolvated SN2 reaction of OH-(H2O) with CH3Cl

    Science.gov (United States)

    Tachikawa, Hiroto

    2006-10-01

    Reaction dynamics for a microsolvated SN2 reaction OH-(H2O)+CH3Cl have been investigated by means of the direct ab initio molecular dynamics method. The relative center-of-mass collision energies were chosen as 10, 15, and 25kcal/mol. Three reaction channels were found as products. These are (1) a channel leading to complete dissociation (the products are CH3OH+Cl-+H2O: denoted by channel I), (2) a solvation channel (the products are Cl-(H2O)+CH3OH: channel II), and (3) a complex formation channel (the products are CH3OH ⋯H2O+Cl-: channel III). The branching ratios for the three channels were drastically changed as a function of center-of-mass collision energy. The ratio of complete dissociation channel (channel I) increased with increasing collision energy, whereas that of channel III decreased. The solvation channel (channel II) was minor at all collision energies. The selectivity of the reaction channels and the mechanism are discussed on the basis of the theoretical results.

  13. Synthesis and Crystal Structure of (H3O)2[Cu3Cl3(H2O)3(NC9H12.5O6)2

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The new compound, (H3O)2[Cu3Cl3(H2O)3(NCgH12.5O6)2] 1, has been synthesized by the hydrothermal reaction and its structure was determined by single-crystal X-ray diffraction.The crystal is of hexagonal, space group P63/m with a = 10.6975(13), c = 14.881 (3)A, V = 1474.8(4)866, R = 0.0517 and wR = 0.0900 for 537 observed reflections (I > 2σ(Ⅰ)). This compound contains two oxonium ions and one [Cu3C13(H2O)3(H0.5ntp)2]2- anion (ntp = nitrilotripropanoato), in which two tridentate ntp ligands connected by three copper(Ⅱ) ions enclose a cage-like unit. Each copper(Ⅱ) ion is coordinated by one water molecule, one chloride ligand and two carboxylate oxygen atoms from two ntp ligands assume a slightly distorted square-planar geometry. There are atoms of the units resulting in two-dimensional sheets and wheel-like three-dimensional interpenetrating frameworks.

  14. Effect of sediment properties on the sorption of C{sub 12}-2-LAS in marine and estuarine sediments

    Energy Technology Data Exchange (ETDEWEB)

    Rico-Rico, Angeles [Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3508 TD Utrecht (Netherlands)], E-mail: a.ricorico@uu.nl; Temara, Ali [Procter and Gamble Company, Central Product Safety, Temselaan 100, 1853 Strombeek-Bever (Belgium); Behrends, Thilo [Department of Earth Sciences-Geochemistry, Faculty of Geosciences, Utrecht University, 3508 TA Utrecht (Netherlands); Hermens, Joop L.M. [Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3508 TD Utrecht (Netherlands)

    2009-02-15

    Linear alkylbenzene sulfonates (LAS) are anionic high production volume surfactants used in the manufacture of cleaning products. Here, we have studied the effect of the characteristics of marine and estuarine sediments on the sorption of LAS. Sorption experiments were performed with single sediment materials (pure clays and sea sand), with sediments treated to reduce their organic carbon content, and with field marine and estuarine sediments. C{sub 12}-2-LAS was used as a model compound. Sorption to the clays montmorillonite and kaolinite resulted in non-linear isotherms very similar for both clays. When reducing the organic content, sorption coefficients decreased proportionally to the fraction removed in fine grain sediments but this was not the case for the sandy sediment. The correlation of the sediment characteristics with the sorption coefficients at different surfactant concentrations showed that at concentrations below 10 {mu}g C{sub 12}-2-LAS/L, the clay content correlated better with sorption, while the organic fraction became more significant at higher concentrations. - Sorption of C{sub 12}-2-LAS to marine sediments mainly depends on both clay and organic carbon content. The importance of each parameter varies with the surfactant concentration.

  15. A spectroscopic study of M rate at C{sub 82} metallofullerenes: Raman, far-infrared, and neutron scattering results

    Energy Technology Data Exchange (ETDEWEB)

    Lebedkin, S.; Renker, B.; Rietschel, H. [Forschungszentrum Karlsruhe (Germany). INFP; Heid, R. [Max-Planck-Institut fuer Physik komplexer Systeme, D-01187 Dresden (Germany); Schober, H. [Institut Laue-Langevin, F-38042 Grenoble (France)

    1998-03-01

    Polycrystalline samples of M rate at C{sub 82} metallofullerenes have been studied at room temperature by Raman (for M=La, Y, Ce, Gd), far-infrared (FIR) (for M=La, Y, Ce), and inelastic neutron scattering (INS) (for M=La, Y) spectroscopy. Raman and FIR spectra suggest that these metallofullerenes have a common dominant, if not a single, structure of the C{sub 82} cage and a similar bonding of the encapsulated metal ion, i.e. the bonding is primarily electrostatic and the metal atoms are in the same oxidation state (+3). The metal ion vibrations are located around 160 and 50 cm{sup -1}. INS reveals no gap between internal vibrational and external vibrational and rotational modes in the range {proportional_to}50-200 cm{sup -1} as is typically observed for other fullerides and also predicted by our model calculations. Presumably this is due to strong intermolecular interactions between M rate at C{sub 82} units in the bulk sample. The studied metallofullerenes are air sensitive, and degradation in air could be followed by changes in the Raman spectra. (orig.) With 6 figs., 2 tabs., 47 refs.

  16. Interaction of multicharged ions with molecules (CO{sub 2}, C{sub 60}) by coincident electron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A. [Universite Paul Sabatier, Toulouse (France). Lab. CAR-IRSAMC

    2001-07-01

    First results for the investigation of electron capture processes in collisions between multicharged ions and molecule targets using electron spectroscopy in coincidence with charged fragments, are presented. It is shown that a much more detailed investigation of the capture reaction can be achieved using molecular instead of heavy atomic targets provided that an analysis of the target dissociation is made. The collisional systems {sup 18}O{sup 8+}+Ar, CO{sub 2} and C{sub 60} have been studied at 80 keV. Non coincident electron spectra as well as first results of double or triple coincidence experiments are discussed. Kinetic energy distributions of the C{sub n}{sup +} fragments (n=1 to 8) produced in multiple capture processes from C{sub 60} target are given. A detailed investigation of the double capture process with CO{sub 2} molecule allows the measurement of kinetic energy release distributions (KERD) which characterize the dissociation of CO{sub 2}{sup 2+} molecular ions; our results are found to be very similar to those measured in double photoionisation experiments. (orig.)

  17. MCD study on Ce-C{sub 82} and Ce{sub 2}-C{sub 80} in the soft-X-ray region

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Jun [Department of Physics, Tokyo Metropolitan University, Hachioji-shi, Tokyo (Japan); Miyahara, Tsuneaki, E-mail: miyaharat@fc.jwu.ac.jp [Department of Mathematical and Physical Sciences, Japan Women' s University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681 (Japan); Hirato, Yasuharu; Ishii, Hiroyoshi [Department of Physics, Tokyo Metropolitan University, Hachioji-shi, Tokyo (Japan); Kodama, Takeshi; Kikuchi, Koichi [Department of Chemistry, Tokyo Metropolitan University, Hachioji-shi, Tokyo (Japan); Nakamura, Tesuya; Kodama, Kenji [Spring-8, Sayo-gun, Hyogo-ken (Japan); Asakura, Daisuke; Koide, Tsuneharu [Photon Factory, High Energy Accelerator Research Organization, KEK, Tsukuba-shi, Ibaraki-ken (Japan)

    2011-04-15

    Highlights: {yields} We measured the temperature dependence of MCD spectra on Ce-C{sub 82} and Ce{sub 2}-C{sub 80}. {yields} We found that Ce 4f moments are antiferromagnetic in Ce-C{sub 82}. {yields} But they are ferromagnetic in Ce{sub 2}-C{sub 80}. {yields} The 4f moments are much smaller than the Hund-ground-state value. {yields} This is caused by a strong crystal field exerted by the carbon cage. - Abstract: We have measured the temperature dependence of MCD spectra on Ce-C{sub 82} and Ce{sub 2}-C{sub 80} in the Ce 3d-4f excitation region. The results show that Ce-C{sub 82} has antiferromagnetic interaction while Ce{sub 2}-C{sub 80} has ferromagnetic interaction between Ce magnetic moments which are much smaller than the Hund-ground-state values.

  18. Enhancement of photocatalytic activity of combustion-synthesized CeO{sub 2}/C{sub 3}N{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dong-Feng; Yang, Ke; Wang, Xiao-qin; Ma, Ya-Li; Huang, Gui-Fang; Huang, Wei-Qing [Hunan University, Department of Applied Physics, School of Physics and Electronics, Changsha (China)

    2015-09-15

    Nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} was synthesized via a one-step solution combustion method using urea as fuel for the first time. The effects of the molar ratio of urea to cerium chloride on the photocatalytic activity of the synthesized samples were investigated. The synthesized nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} shows small size and large surface exposure area. Photocatalytic degradation of methylene blue demonstrates that the synthesized nanocrystalline CeO{sub 2}/C{sub 3}N{sub 4} possesses enhanced photocatalytic activity. It is proposed that the enhanced photocatalytic activity might be related to the favorable morphology and structure, and the effective charge separation between C{sub 3}N{sub 4} and CeO{sub 2} in the photocatalytic process. (orig.)

  19. Interaction of protons with the C{sub 60} molecule: calculation of deposited energies and electronic stopping cross sections (v{sub {<=}}5 au)

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P. [Laboratoire CAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)]. E-mail: pmc@irsamc.ups-tlse.fr; Bordenave-Montesquieu, D.; Rentenier, A.; Bordenave-Montesquieu, A. [Laboratoire CAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)

    2001-09-28

    The energy deposited by a proton in a C{sub 60} molecule is calculated over a broad collision velocity range from 0.1 to 5 au, using the free-electron gas model of Lindhard and Winther (1964 Mat. Fys. Medd. K Dan. Vidensk. Selsk. 34) and the C{sub 60} electron density distribution calculated by Puska and Nieminen. The energy lost by the proton is maximum near 1.8 au collision velocity in contrast with the saturation found in the low-velocity regime, in the 0.25-0.5 au velocity range, by Kunert and Schmidt. From the impact parameter dependence we deduce the distributions of deposited energies, the averaged energy losses and the C{sub 60} electronic stopping cross sections. It is found that the C{sub 60} molecule behaves as a carbon foil giving very similar absolute stopping cross sections per atom. (author). Letter-to-the-editor.

  20. Enhanced luminescence and white light emission from Eu(3+) -co-doped K3 Ca2 (SO4 )3 Cl:Dy(3+) phosphor with near visible ultraviolet excitation for white LEDs.

    Science.gov (United States)

    Baig, N; Dhoble, N S; Park, K; Kokode, N S; Dhoble, S J

    2015-06-01

    The luminescent properties of europium (Eu)- and dysprosium (Dy)-co-doped K3 Ca2 (SO4 )3 Cl halosulfate phosphors were analyzed. This paper reports the photoluminescence (PL) properties of K3 Ca2 (SO4 )3 Cl microphosphor doped with Eu and Dy and synthesized using a cost-effective wet chemical method. The phosphors were characterized by X-ray diffraction and scanning electron microscopy. The CIE coordinates were calculated to display the color of the phosphor. PL emission of the prepared samples show peaks at 484 nm (blue), 575 nm (yellow), 594 nm (orange) and 617 nm (red). The emission color of the Eu,Dy-co-doped K3 Ca2 (SO4 )3 Cl halophosphor depends on the doping concentration and excitation wavelength. The addition of Eu in K3 Ca2 (SO4 )3 Cl:Dy greatly enhances the intensity of the blue and yellow peaks, which corresponds to the (4)  F9/2  → (6) H15/2 and (4)  F9/2  → (6) H13/2 transitions of Dy(3+) ions (under 351 nm excitation). The Eu(3+) /Dy(3+) co-doping also produces white light emission for 1 mol% of Eu(3+) , 1 mol% of Dy(3+) in the K3 Ca2 (SO4 )3 Cl lattice under 396 nm excitation, for which the calculated chromaticity coordinates are (0.35, 0.31). Thus, K3 Ca2 (SO4 )3 Cl co-doped with Eu/Dy is a suitable candidate for NUV based white light-emitting phosphors technology. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Preparation and characterization of ultrathin [Ru(CO)3Cl2]2 and [BMIM][Tf2N] films on Al2O3/NiAl(110) under UHV conditions.

    Science.gov (United States)

    Sobota, Marek; Schernich, Stefan; Schulz, Hannes; Hieringer, Wolfgang; Paape, Natalia; Wasserscheid, Peter; Görling, Andreas; Laurin, Mathias; Libuda, Jörg

    2012-08-14

    Towards a better understanding of the interface chemistry of ionic liquid (IL) thin film catalytic systems we have applied a rigorous surface science model approach. For the first time, a model homogeneous catalyst has been prepared under ultrahigh vacuum conditions. The catalyst, di-μ-chlorobis(chlorotricarbonylruthenium) [Ru(CO)(3)Cl(2)](2), and the solvent, the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][Tf(2)N], have been deposited by physical vapor deposition onto an alumina model support [Al(2)O(3)/NiAl(110)]. First, the interaction between thin films of [Ru(CO)(3)Cl(2)](2) and the support is investigated. Then, the ruthenium complex is co-deposited with the IL and the influence of the solvent on the catalyst is discussed. D(2)O, which is a model reactant, is further added. Growth, surface interactions, and mutual interactions in the thin films are studied with IRAS in combination with density functional (DFT) calculations. At 105 K, molecular adsorption of [Ru(CO)(3)Cl(2)](2) is observed on Al(2)O(3)/NiAl(110). The IRAS spectra of the binary [Ru(CO)(3)Cl(2)](2) + [BMIM][Tf(2)N] and ternary [Ru(CO)(3)Cl(2)](2) + [BMIM][Tf(2)N] + D(2)O show every characteristic band of the individual components. Above 223 K, partial decomposition of the ruthenium complex leads to species of molecular nature attributed to Ru(CO) and Ru(CO)(2) surface species. Formation of metallic ruthenium clusters occurs above 300 K and the model catalyst decomposes further at higher temperatures. Neither the presence of the IL nor of D(2)O prevents this partial decomposition of [Ru(CO)(3)Cl(2)](2) on alumina.

  2. Effect of Cr{sub 3}C{sub 2} content on the microstructure and properties of Mo{sub 2}NiB{sub 2}-based cermets

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Lang; Li, XiaoBo; Zhang, Dan; Yang, ChengMing; Yin, FuCheng [Xiangtan Univ., Hunan (China). School of Materials Science and Engineering; Xiangtan Univ., Hunan (China). Key Lab. of Materials Design and Preparation Technology of Hunan Province; Xiangtan Univ., Hunan (China). Key Lab. of Low Dimensional Materials and Application Technology of Ministry of Education; Xiao, YiFeng [Xiangtan Univ., Hunan (China). Key Lab. of Materials Design and Preparation Technology of Hunan Province

    2015-10-15

    Four series of Mo{sub 2}NiB{sub 2}-based cermets with Cr{sub 3}C{sub 2} addition of between 0 and 7.5 wt.% in 2.5 wt.% increments were studied by means of scanning electron microscopy, energy dispersive X-ray analysis and X-ray diffractometry. The transverse rupture strength and hardness were also measured. It was found that Cr{sub 3}C{sub 2} completely dissolved in Mo{sub 2}NiB{sub 2}-based cermets. Cr{sub 3}C{sub 2} addition improved the wettability of the Ni binder phase on the Mo{sub 2}NiB{sub 2} hard phase, which resulted in a decrease in the porosity and an increase in the phase uniformity. The cermets with 2.5 wt.% Cr{sub 3}C{sub 2} content showed relatively fine grains and almost full density. A high Cr{sub 3}C{sub 2} content resulted in the formation of M{sub 6}C (M = Mo, Cr, Ni) phase. In addition, energy dispersive X-ray spectroscopy results showed that the content of Mo in the binder decreased with increasing Cr{sub 3}C{sub 2} content. The cermets with 2.5 wt.% Cr{sub 3}C{sub 2} addition exhibited the highest transverse rupture strength of 2210 MPa, whereas the cermets without Cr{sub 3}C{sub 2} addition exhibited the highest hardness.

  3. Stability of zinc phthalocyanine and fullerene C{sub 60} organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lessmann, Rudolf

    2010-05-10

    Organic solar cells promise electricity generation at very low cost, and higher installation flexibility as compared to inorganic solar cells. The lower cost is achieved by cheaper semiconductors and easier manufacturing processes. The flexibility is naturally given by these ultra-thin, amorphous layers. Also the power conversion efficiency can be high enough for many applications. The organic molecules have to withstand the constant excitation by photons, transport of energy in form of excitons and charge. A small but significant amount of these photons has energy over the absorption gap, the excess of energy must be released without breaking the molecular bonds. In consequence, the solar cells can also heat up to temperatures at above 80 C. The objective of this work is to answer the question if the small molecules organic solar cells can be stable enough to operate under a very long time. The stability of organic doped layers in an organic solar cell is also addressed. This work starts with a general introduction followed by the description of the experimental procedures. The aging experiments of the solar cell were done with a self developed equipment. The fabrication of this equipment (a set of measurement boxes) was necessary to maintain the conditions, under which a solar cell can be aged, as constant as possible. The measurement boxes were used to control the electrical load of the cell, its temperature, the illumination intensity, and its electric connection to the I vs. V measurement equipment. A software package was also developed to control the equipment and to facilitate the work and visualization of the high volume of collected data. The model solar cells chosen for the aging experiments were donor-acceptor heterojunctions devices formed with the well-known materials C{sub 60} and ZnPc. Two basic different structures were analyzed, because they offered reasonable performance and potentially long lifetime: the flat heterojunction (FHJ) and the mixed

  4. Solvothermal synthesis of Fe{sub 7}C{sub 3} and Fe{sub 3}C nanostructures with phase and morphology control

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Brent; Clifford, Dustin; Carpenter, Everett E., E-mail: aelgendy@vcu.edu, E-mail: ecarpenter2@vcu.edu [Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); El-Gendy, Ahmed A., E-mail: aelgendy@vcu.edu, E-mail: ecarpenter2@vcu.edu [Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Nanotechnology and Nanometrology Laboratory, National Institute for Standards, Giza 12211 (Egypt)

    2016-07-21

    A phase transition, from orthorhombic Fe{sub 3}C to hexagonal Fe{sub 7}C{sub 3}, was observed using a wet synthesis mediated by hexadecyltrimethylammonium chloride (CTAC). In this study, CTAC has been shown to control carbide phase, morphology, and size of the iron carbide nanostructures. Fe{sub 7}C{sub 3} hexagonal prisms were formed with an average diameter of 960 nm, the thickness of 150 nm, and Fe{sub 3}C nanostructures with an approximate size of 50 nm. Magnetic studies show ferromagnetic behavior with M{sub s} of 126 emu/g, and H{sub c} of 170 Oe with respect to Fe{sub 7}C{sub 3} and 95 emu/g and 590 Oe with respect to Fe{sub 3}C. The thermal studies using high temperature x-ray diffraction show stability of Fe{sub 7}C{sub 3} up to 500 °C. Upon slow cooling, the Fe{sub 7}C{sub 3} phase is recovered with an intermediate oxide phase occurring around 300 °C. This study has demonstrated a simple route in synthesizing iron carbides for an in depth magnetic study and crystal phase transition study of Fe{sub 7}C{sub 3} at elevated temperatures.

  5. C/sub 4/ photosynthesis in Euphorbia degeneri and E. remyi: a comparison of photosynthetic carbon metabolism in leaves, callus cultures and regenerated plants

    Energy Technology Data Exchange (ETDEWEB)

    Ruzin, S.E.

    1984-04-01

    Based on analysis of /sup 14/CO/sub 2/ fixation kinetics and assays of enzymes related to C/sub 4/ metabolism (NAD-ME, NADP-ME, NAD-MDH, NADP-MDH, AST, ALT), leaves and regenerated plants of Euphorbia degeneri exhibit a modified NADP-ME-type photosynthesis. Apparently, both aspartate and malate are used for transport of CO/sub 2/ to bundle sheath cells. Callus grown on either non-shoot-forming or shoot-forming media fixes CO/sub 2/ into RPP-cycle intermediates and sucrose, as well as malate and aspartate. /sup 14/CO/sub 2/ pulse/chase kinetics show no significant loss of label from C/sub 4/ acids throughout a one minute chase. Analysis of PEPCase revealed the presence of 2 isoenzymes in both leaf and regenerated plant tissues (K/sub m/ (PEP) = 0.080 and 0.550) but only one isoenzyme in callus (K/sub m/ = 0.100). It appears that C/sub 4/ photosynthesis does not occur in callus derived from this C/sub 4/ dicot but is regenerated concomitant with shoot regeneration, and ..beta..-carboxylation of PEP in callus, mediated by the low K/sub m/ isoenzyme of PEPCase, produces C/sub 4/ acids that are not involved in the CO/sub 2/ shuttle mechanism characteristic of C/sub 4/ photosynthesis. 161 references, 19 figures, 12 tables.

  6. Validation of HNO3, ClONO2, and N2O5 from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    M. Ridolfi

    2008-02-01

    Full Text Available The Atmospheric Chemistry Experiment (ACE satellite was launched on 12 August 2003. Its two instruments measure vertical profiles of over 30 atmospheric trace gases by analyzing solar occultation spectra in the ultraviolet/visible and infrared wavelength regions. The reservoir gases HNO3, ClONO2, and N2O5 are three of the key species provided by the primary instrument, the ACE Fourier Transform Spectrometer (ACE-FTS. This paper describes the ACE-FTS version 2.2 data products, including the N2O5 update, for the three species and presents validation comparisons with available observations. We have compared volume mixing ratio (VMR profiles of HNO3, ClONO2, and N2O5 with measurements by other satellite instruments (SMR, MLS, MIPAS, aircraft measurements (ASUR, and single balloon-flights (SPIRALE, FIRS-2. Partial columns of HNO3 and ClONO2 were also compared with measurements by ground-based Fourier Transform Infrared (FTIR spectrometers. Overall the quality of the ACE-FTS v2.2 HNO3 VMR profiles is good from 18 to 35 km. For the statistical satellite comparisons, the mean absolute differences are generally within ±1 ppbv (±20% from 18 to 35 km. For MIPAS and MLS comparisons only, mean relative differences lie within ±10% between 10 and 36 km. ACE-FTS HNO3 partial columns (~15–30 km show a slight negative bias of −1.3% relative to the ground-based FTIRs at latitudes ranging from 77.8° S–76.5° N. Good agreement between ACE-FTS ClONO2 and MIPAS, using the Institut für Meteorologie und Klimaforschung and Instituto de Astrofísica de Andalucía (IMK-IAA data processor is seen. Mean absolute differences are typically within ±0.01 ppbv between 16 and 27 km and less than +0.09 ppbv between 27 and 34 km. The ClONO2 partial column comparisons show varying degrees of agreement, depending on the location and the quality of the FTIR measurements. Good agreement was found for the comparisons with the midlatitude Jungfraujoch partial columns for which

  7. Validation of HNO3, ClONO2, and N2O5 from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    P. Raspollini

    2008-07-01

    Full Text Available The Atmospheric Chemistry Experiment (ACE satellite was launched on 12 August 2003. Its two instruments measure vertical profiles of over 30 atmospheric trace gases by analyzing solar occultation spectra in the ultraviolet/visible and infrared wavelength regions. The reservoir gases HNO3, ClONO2, and N2O5 are three of the key species provided by the primary instrument, the ACE Fourier Transform Spectrometer (ACE-FTS. This paper describes the ACE-FTS version 2.2 data products, including the N2O5 update, for the three species and presents validation comparisons with available observations. We have compared volume mixing ratio (VMR profiles of HNO3, ClONO2, and N2O5 with measurements by other satellite instruments (SMR, MLS, MIPAS, aircraft measurements (ASUR, and single balloon-flights (SPIRALE, FIRS-2. Partial columns of HNO3 and ClONO2 were also compared with measurements by ground-based Fourier Transform Infrared (FTIR spectrometers. Overall the quality of the ACE-FTS v2.2 HNO3 VMR profiles is good from 18 to 35 km. For the statistical satellite comparisons, the mean absolute differences are generally within ±1 ppbv ±20% from 18 to 35 km. For MIPAS and MLS comparisons only, mean relative differences lie within±10% between 10 and 36 km. ACE-FTS HNO3 partial columns (~15–30 km show a slight negative bias of −1.3% relative to the ground-based FTIRs at latitudes ranging from 77.8° S–76.5° N. Good agreement between ACE-FTS ClONO2 and MIPAS, using the Institut für Meteorologie und Klimaforschung and Instituto de Astrofísica de Andalucía (IMK-IAA data processor is seen. Mean absolute differences are typically within ±0.01 ppbv between 16 and 27 km and less than +0.09 ppbv between 27 and 34 km. The ClONO2 partial column comparisons show varying degrees of agreement, depending on the location and the quality of the FTIR measurements. Good agreement was found for the comparisons with the midlatitude Jungfraujoch partial columns for which

  8. Concurrent Phenomena at the Reaction Path of the SN2 Reaction CH3Cl + F−. Information Planes and Statistical Complexity Analysis

    Directory of Open Access Journals (Sweden)

    Moyocoyani Molina-Espíritu

    2013-09-01

    Full Text Available An information-theoretical complexity analysis of the SN2 exchange reaction for CH3Cl + F− is performed in both position and momentum spaces by means of the following composite functionals of the one-particle density: D-L and I-J planes and Fisher-Shannon’s (FS and López-Ruiz-Mancini-Calbet (LMC shape complexities. It was found that all the chemical concepts traditionally assigned to elementary reactions such as the breaking/forming regions (B-B/F, the charge transfer/reorganization and the charge repulsion can be unraveled from the phenomenological analysis performed in this study through aspects of localizability, uniformity and disorder associated with the information-theoretical functionals. In contrast, no energy-based functionals can reveal the above mentioned chemical concepts. In addition, it is found that the TS critical point for this reaction does not show any chemical meaning (other than the barrier height as compared with the concurrent processes revealed by the information-theoretical analysis. Instead, it is apparent from this study that a maximum delocalized state could be identified in the transition region which is associated to the charge transfer process as a new concurrent phenomenon associated with the charge transfer region (CT for the ion-complex is identified. Finally it is discussed why most of the chemical features of interest (e.g., CT, B-B/F are only revealed when some information-theoretic properties are taken into account, such as localizability, uniformity and disorder.

  9. Assessment of serum CX3CL1/fractalkine level in Han Chinese girls with anorexia nervosa and its correlation with nutritional status: a preliminary cross-sectional study.

    Science.gov (United States)

    Zhang, Shengkang; Tang, Hanfeng; Gong, Cai; Liu, Jiang; Chen, Jindong

    2017-02-01

    The chemokine (C-X3-C motif) ligand 1 (CX3CL1), also named fractalkine (FKN), has been implicated in psychiatric disorders and functions as a novel adipocytokine. However, no attention has been paid to the role of FKN in anorexia nervosa (AN). The current study was performed to explore FKN levels in AN to determine its role in the involvement of AN. A total of 96 girls aged 11-18 years with AN (n=34), healthy controls (HC; n=32) and simple obesity (OB, n=30) were enrolled in the cross-sectional study. Blood samples were collected during the fasting state. Serum FKN concentrations were determined using ELISA. The skinfold thickness (TSF) of the biceps and triceps as well as mid-arm muscle circumference (MAMC) were used to determine the nutritional status. Our results showed that serum FKN levels were significantly lower in the AN group than in the control and OB groups. After adjusting for body mass index (BMI), FKN concentrations in the AN group were statistically higher than in the HC and OB groups. Significant correlations between serum FKN and body weight, BMI, Cole index and serum insulin were observed. In addition, serum FKN levels were positively related to TSF and MAMC in all subjects. Serum FKN concentrations are attenuated in girls with AN compared with healthy adolescents and are positively related to nutritional status. The lower FKN levels may be regulated by nutrition status and response to starvation. After adjusting for BMI, higher FKN levels may reflect that persistent inflammation is present in patients with AN. Copyright © 2016 American Federation for Medical Research.

  10. Stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O from measurements made by the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    P. F. Bernath

    2013-02-01

    Full Text Available Long lived halogen-containing compounds are important atmospheric constituents since they can act both as a source of chlorine radicals, which go on to catalyse ozone loss, and as powerful greenhouse gases. The long term impact of these species on the ozone layer is dependent on their stratospheric lifetimes. Using observations from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS we present calculations of the stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O. The lifetimes were calculated using the slope of the tracer-tracer correlation of these species with CFC-11 at the tropopause. The correlation slopes were corrected for the changing atmospheric concentrations of each species based on age of air and CFC-11 measurements from samples taken aboard the Geophysica aircraft – along with the effective linear trend of the VMR from tropical ground-based AGAGE sites. Stratospheric lifetimes were calculated using a CFC-11 lifetime of 45 yr. These calculations produced values of 113 + (− 26 (18 yr (CFC-12, 35 + (− 11 (7 yr (CCl4, 195 + (− 75 (42 yr (CH4, 69 + (− 65 (23 yr (CH3Cl and 123 + (− 53 (28 yr (N2O. The errors on these values are the weighted 1-σ non-systematic errors. The stratospheric lifetime of CH3Cl represents the first calculations of the stratospheric lifetime of CH3Cl using data from a space based instrument.

  11. An integral parametrization of the bacterial growth curve experimental demonstration with E. coli C{sub 6}00 bacteria; Parametrizacion integrada de la curva de crecimiento bacteriano. Comprobacion experimental para E. coli C{sub 6}00

    Energy Technology Data Exchange (ETDEWEB)

    Garces, F.; Vidania, R. de

    1984-07-01

    In this work an integral parametrization of the bacterial growth curve is presented. The values of the parameters are obtained by fitting to the experimental data. Those parameters, with allow to describe the growth in its different phases, are the followings: slopes of the curve in its three parts and the time which divides the last two phases of the bacterial growth. The experimental data are bacterial densities measured by optical methods. The bacteria used was the E. coli C{sub 6}00. (Author)

  12. Image quality and volume computed tomography air kerma index (C{sub vol}) evaluation in Recife; Avaliacao da qualidade de imagem e do indice volumetrico de Kerma ar em tomografia computadorizada (C{sub vol}) em Recife

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Marcos Ely Almeida

    2008-07-01

    The Computed Tomography (CT) is an important diagnostic imaging method, widely used. However, in spite of all the advantages and technologic advances within the CT scanners, the tomographic procedures result in high absorbed doses to patients. The main objective of this work was to perform a dosimetric study of CT scanners located at Recife and to evaluate the image quality on CT examinations in these equipment. The volume CT air kerma index (C{sub VOL}) and air kerma length product (P{sub KL,CT}) were estimated. These values were calculated using normalized weighted air kerma indexes in CT standard dosimetry phantoms ({sub n}C{sub W}), supplied by ImPACT group for several CT scanners, and the scan parameters of routine head, routine chest and hi-resolution chest CT exams performed at 20 institutions. The irradiation parameters of 15 adult patients for each CT procedure were registered at six participating centres, at which the phantom from the American College of Radiology (ACR) CT accreditation protocol was used for the image quality measurements. For routine head exams, the C{sub VOL} values varied between 12 and 58 mGy (at the posterior fossa) and 15 to 58 mGy (at the cerebrum) and the P{sub KL,CT}, from 150 to 750 mGy{center_dot}cm. The C{sub VOL} values for routine chest procedures varied from 3 to 26 mGy and the P{sub KL,CT}, between 120 and 460 mGy{center_dot}cm. In relation to Hi-resolution chest exams, C{sub VOL} values were from 1.0 to 2.7 mGy and the P{sub KL,CT} values varied between 24 and 67 mGy{center_dot}cm. The image quality evaluations results showed that almost all scanners presented at least one inadequacy. One of the equipment presented faults at 70% of the tests. With regard to the image noise, only two scanners presented acceptable results. From these results, it is possible to conclude that the volume CT air kerma index values are lower than the European reference levels. However, the image quality of these CT scanners does not attend the

  13. Surface modified MXene Ti{sub 3}C{sub 2} multilayers by aryl diazonium salts leading to large-scale delamination

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongbing [College of Mechanics and Materials, Hohai University, Nanjing, Jiangsu Province 210098 (China); Department of Mathematics and Physics, Nanjing Institute of Technology, Nanjing, Jiangsu Province 211167 (China); Zhang, Jianfeng, E-mail: jfzhang_sic@163.com [College of Mechanics and Materials, Hohai University, Nanjing, Jiangsu Province 210098 (China); Wu, Yuping; Huang, Huajie; Li, Gaiye; Zhang, Xin; Wang, Zhuyin [College of Mechanics and Materials, Hohai University, Nanjing, Jiangsu Province 210098 (China)

    2016-10-30

    Highlights: • A novel and simple method to delaminate MXene Ti{sub 3}C{sub 2} multilayers. • Surface modification using aryl diazonium salts induced swelling that conversely weakened the bonds between MXene layers. • The grafting of phenylsulfonic acid groups on MXene surfaces resulted in excellent water dispersibility. - Abstract: Herein we report a simple and facile method to delaminate MXene Ti{sub 3}C{sub 2} multilayers by the assistance of surface modification using aryl diazonium salts. The basic strategy involved the preparation of layered MAX Ti{sub 3}AlC{sub 2} and the exfoliation of Ti{sub 3}AlC{sub 2} into Ti{sub 3}C{sub 2} multilayers, followed by Na{sup +} intercalation and surface modification using sulfanilic acid diazonium salts. The resulting chemically grafted Ti{sub 3}C{sub 2} flakes were characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. Ultraviolet-visible spectroscopy revealed that surface-modified MXene Ti{sub 3}C{sub 2} sheets disperse well in water and the solutions obey Lambert–Beer’s law. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to demonstrate the morphology and structure of delaminating MXene Ti{sub 3}C{sub 2} flakes. The results indicated that chemical modification for MXene multilayers by aryl diazonium salts induced swelling that conversely weakened the bonds between MX layers, hence leading to large-scale delamination of multilayered MXene Ti{sub 3}C{sub 2}via mild sonication. Advantages of the present approach rely not only on the simplicity and efficiency of the delamination procedure but also on the grafting of aryl groups to MXene surfaces, highly suitable for further applications of the newly discovered two-dimensional materials.

  14. Molecular dynamics investigations on the interfacial energy and adhesive strength between C{sub 60}-filled carbon nanotubes and metallic surface

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Jenn-Kun [Department of Greenergy, National University of Tainan, Tainan 70005, Taiwan (China); Huang, Pei-Hsing, E-mail: phh@mail.npust.edu.tw [Department of Mechanical Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan (China); Wu, Wei-Te; Hsu, Yi-Cheng [Department of Biomechatronics Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan (China)

    2014-01-15

    The mechanical and adhesive properties of C{sub 60}@(10,10) carbon nanopeapods (CNPs) adhering to gold surfaces are investigated by atomistic simulations. The effects of C{sub 60} fill density, tube length, surrounding temperature, and peeling velocity on the adhesion behavior are studied. Results show that the interfacial binding energy of CNPs (which depends on the C{sub 60} fill density and temperature) is 2.0∼4.4% higher than that of (10,10) single-walled CNTs and 3.4∼4.7% lower than that of (5,5)@(10,10) double-walled CNTs (DWCNTs). Despite their lower interfacial binding energy, CNPs have a higher adhesive strength than that of DWCNTs (1.53 nN vs. 1.4 nN). Distinct from the inner tubes of DWCNTs, which have continuum mechanical properties, the discrete C{sub 60} molecules that fill CNPs exhibit unique composite mechanical properties, with high flexibility and bend-buckling resistance. The bend-buckling forces for CNPs filled with a low/medium fill density of C{sub 60} are approximately constant. When the fill density is 1 C{sub 60} molecule per nanometer length, the bend-buckling force dramatically increases. - Highlights: • Adhesion and peeling behaviors of CNPs on metallic substrates are investigated. • Effects of C60 density, CNP length, temperature, and peeling velocity are studied. • CNPs have a higher adhesive strength than that of DWCNTs (1.53 nN vs. 1.4 nN). • Discrete C{sub 60} molecules that fill CNPs exhibit unique composite mechanical properties.

  15. Analysis of fragment size distributions in collisions of monocharged ions with the C{sub 60} molecule

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A; Moretto-Capelle, P; Bordenave-Montesquieu, D; Bordenave-Montesquieu, A [LCAR-IRSAMC, UMR 5589 Universite Paul Sabatier-CNRS, 118 rte de Narbonne, 31062 Toulouse Cedex (France)

    2005-04-14

    Fragmentation of the C{sub 60} molecule is investigated using a multicorrelation technique. We first focus on the transition from asymmetrical dissociation (AD) to multifragmentation (MF). These processes are studied in collisions between H{sup +}{sub x}(x = 1-3) hydrogenic projectiles and C{sub 60} fullerene in the gas phase, in the 2-130 keV collisional energy range. A rather sharp transition from pure AD to predominant MF is observed when plotting the AD/(AD + MF) ratio against the average deposited energy E{sub dep}; it occurs in the 80-240 eV E{sub dep} range; this ratio is also found to be independent of the projectile species (scaling law). The evolution of the size distribution shape is also discussed and compared with other data available in the literature. A pure power law is never reached in the present experimental conditions. Finally, an event-by-event analysis of the fragmentation data is developed for the first time in the study of the C{sub 60} molecule fragmentation and discussed in terms of the predictions of the percolation model near a critical behaviour. Moments of order 2, 3 and 5 are determined for each correlation event. Moments of order 3 and 5 follow a linear behaviour when plotted against the moment of order 2, as predicted, and the exponent {tau} that is extracted takes a value near 2. The Campi scatter plot is also determined and discussed for total and multiplicity-selected events. Both slopes of the two branches in the Campi plots and {tau} value are near those that are expected in the percolation of a 2D lattice.

  16. Fractalkine/CX3CL1 protects striatal neurons from synergistic morphine and HIV-1 Tat-induced dendritic losses and death

    Directory of Open Access Journals (Sweden)

    Suzuki Masami

    2011-11-01

    Full Text Available Abstract Background Fractalkine/CX3CL1 and its cognate receptor CX3CR1 are abundantly expressed in the CNS. Fractalkine is an unusual C-X3-C motif chemokine that is important in neuron-microglial communication, a co-receptor for HIV infection, and can be neuroprotective. To assess the effects of fractalkine on opiate-HIV interactive neurotoxicity, wild-type murine striatal neurons were co-cultured with mixed glia from the striata of wild-type or Cx3cr1 knockout mice ± HIV-1 Tat and/or morphine. Time-lapse digital images were continuously recorded at 20 min intervals for up to 72 h using computer-aided microscopy to track the same cells repeatedly. Results Co-exposure to Tat and morphine caused synergistic increases in neuron death, dendritic pruning, and microglial motility as previously reported. Exogenous fractalkine prevented synergistic Tat and morphine-induced dendritic losses and neuron death even though the inflammatory mediator TNF-α remained significantly elevated. Antibody blockade of CX3CR1 mimicked the toxic effects of morphine plus Tat, but did not add to their toxicity; while fractalkine failed to protect wild-type neurons co-cultured with Cx3cr1-/--null glia against morphine and Tat toxicity. Exogenous fractalkine also normalized microglial motility, which is elevated by Tat and morphine co-exposure, presumably limiting microglial surveillance that may lead to toxic effects on neurons. Fractalkine immunofluorescence was expressed in neurons and to a lesser extent by other cell types, whereas CX3CR1 immunoreactivity or GFP fluorescence in cells cultured from the striatum of Cx3cr1-/- (Cx3cr1GFP/GFP mice were associated with microglia. Immunoblotting shows that fractalkine levels were unchanged following Tat and/or morphine exposure and there was no increase in released fractalkine as determined by ELISA. By contrast, CX3CR1 protein levels were markedly downregulated. Conclusions The results suggest that deficits in fractalkine

  17. On the photoconductivity of layered molecular complex of fullerene C{sub 60} with saturated amine TMPDA

    Energy Technology Data Exchange (ETDEWEB)

    Golovin, Yu.I.; Lopatin, D.V.; Rodaev, V.V. [Tambov State University, 392000 Tambov (Russian Federation); Konarev, D.V.; Litvinov, A.L.; Lyubovskaya, R.N. [Institute of Problems of Chemical Physics, Russian Academy of Science, 142432 Chernogolovka, Moscow (Russian Federation)

    2007-03-15

    It was revealed that the photoconductivity of layered molecular complex of fullerene C{sub 60} with saturated amine TMPDA: TMPDA.C{sub 60} is caused by intermolecular electronic processes in the fullerene layers. The intermediate magneto-sensitive stage of photogenerating free charge carriers was found to be due to the effect of magnetic field on the rate constant of the triplet charge transfer exciton annihilation process. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Synthesis of ultrafine powder of vanadium carbide V{sub 8}C{sub 7} by microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaenko, Irina [Russian Academy of Sciences, Yekaterinburg (Russian Federation). Inst. of Solid State Chemistry; Yeltsin Ural Federal Univ., Yekaterinburg (Russian Federation); Krasovskaya, Anastasiya [Yeltsin Ural Federal Univ., Yekaterinburg (Russian Federation); Kedin, Nikolay; Shveikin, Gennadii [Russian Academy of Sciences, Yekaterinburg (Russian Federation). Inst. of Solid State Chemistry

    2015-10-15

    In this article a new method of synthesizing ultrafine powder of vanadium carbide V{sub 8}C{sub 7} by a combination of classic liquid-phase precipitation on a carbon support and low-temperature microwave heat treatment is proposed. An entire spectrum of intermediates obtained during thermolysis, reduction, and carbidization of precursors to the final product has been presented. The structure, morphology and distribution according to the particle size, phase structure and specific surface area of samples has been shown.

  19. Effect of pregnancy or treatment with ethinylestradiol or phenobarbital on the glucuronidation of. beta. -estradiol at the C/sub 3/-OH vs C/sub 17/-OH in female rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Connors, M.S.

    1986-01-01

    The glucuronidation of (/sup 3/H)-estradiol-17..beta.. (E/sub 2/) at the C/sub 3/ vs the C/sub 17/ hydroxyl groups was determined in female Sprague-Dawley rat liver microsomes. An HPLC method was developed to resolve the glucuronide conjugates which were then quantitated by liquid scintillation counting. The rates of formation of 17..beta..-estradiol 3-(..beta..-D-glucuronide) (E/sub 2/3G) and ..beta..-estradiol 17-(..beta..-D-glucuronide) (E/sub 2/17G) were 0.49 +- 0.03 and 0.40 +- 0.02 nmolminmg protein respectively. The apparent K/sub m/ and V/sub max/ of E/sub 2/ glucuronidation were determined in control, pregnant (day 19 of gestation), phenobarbital treated (PB; 80 mgkgday ip for 5 days) and ethinylestradiol treated (EE/sub 2/; 5 mgkgday ip for 5 days) female rats. Two methods were chosen for data analysis and the validity of these methods was compared. The least squares estimates of K/sub m/ and V/sub max/ values as well as the confidence contours of the joint sums of squares for the parameter spaces were calculated

  20. Development of Cr{sub 3}C{sub 2}-25(Ni20Cr) nanostructured coatings; Desenvolvimento de revestimentos nanostruturados de Cr{sub 3}C{sub 2}-25(Ni20Cr)

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Cecilio Alvares da

    2012-07-01

    This study is divided in two parts. The first part is about the preparation of nanostructured Cr{sub 3}C{sub 2}-25(Ni20Cr) powders by high energy milling followed by characterization of the milled and the as received powder. Analyses of some of the data obtained were done using a theoretical approach. The second part of this study is about the preparation and characterization of coatings prepared with the nanostructured as well as the as received Cr{sub 3}C{sub 2}-25(Ni20Cr) powders. The high temperature erosion-oxidation (E-O) behavior of the coatings prepared with the two types of powders has been compared based on a technological approach. The average crystallite size of the Cr{sub 3}C{sub 2}-25(Ni20Cr) powder decreased rapidly from 145 nm to 50 nm in the initial stages of milling and thereafter decreased slowly to a steady state value of around 10 nm with further increase in milling time. This steady state corresponds to the beginning of a dynamic recovery process. The maximum lattice strain ({epsilon} = 1,17%) was observed in powders milled for 16 hours, and this powders critical crystallite size was 28 nm. In contrast, the lattice parameter attained a minimum for powders milled for 16 hours. Upon reaching the critical crystallite size, the dislocation density attained a steady state regime and all plastic deformation introduced in the material there after was in the form of events occurring at the grain boundaries, due mainly to grain boundary sliding. The deformation energy stored in the crystal lattice of the Cr{sub 3}C{sub 2}-25(Ni20Cr) powders milled for different times was determined from enthalpy variation measurements. These results indicated that the maximum enthalpy variation ({delta}H = 722 mcal) also occurred for powders milled for 16 hours. In a similar manner, the maximum specific heat variation ({delta}C{sub p} = 0,278 cal/gK) occurred for powders milled for 16 hours. The following mechanical properties of Cr{sub 3}C{sub 2}-25(Ni20Cr) coatings

  1. Anharmonic rovibrational calculations of singlet cyclic C{sub 4} using a new ab initio potential and a quartic force field

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaohong; Bowman, Joel M., E-mail: jmbowma@emory.edu [Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States); Huang, Xinchuan [SETI Institute, 189 Bernardo Ave, Suite 100, Mountain View, California 94043 (United States); Lee, Timothy J., E-mail: Timothy.J.Lee@nasa.gov [MS 245-1, NASA Ames Research Center, Mofffett Field, California 94035 (United States)

    2013-12-14

    We report a CCSD(T)/cc-pCV5Z quartic force field (QFF) and a semi-global CCSD(T)-F12b/aug-cc-pVTZ potential energy surface (PES) for singlet, cyclic C{sub 4}. Vibrational fundamentals, combinations, and overtones are obtained using vibrational second-order perturbation theory (VPT2) and the vibrational configuration-interaction (VCI) approach. Agreement is within 10 cm{sup −1} between the VCI calculated fundamentals on the QFF and PES using the MULTIMODE (MM) program, and VPT2 and VCI results agree for the fundamentals. The agreement between VPT2-QFF and MM-QFF results is also good for the C{sub 4} combinations and overtones. The J = 1 and J = 2 rovibrational energies are reported from both VCI (MM) on the PES and VPT2 on the QFF calculations. The spectroscopic constants of {sup 12}C{sub 4} and two C{sub 2v}-symmetry, single {sup 13}C-substituted isotopologues are presented, which may help identification of cyclic C{sub 4} in future experimental analyses or astronomical observations.

  2. Single and double reduction of C{sub 60} in 2:1 {gamma}-cyclodextrin/[60]fullerene inclusion complexes by cyclodextrin radicals

    Energy Technology Data Exchange (ETDEWEB)

    Quaranta, Annamaria [Laboratoire de Chimie et Biochimie des Substances Naturelles, MNHN, UMR5154 CNRS-MNHN/USM50502, 63 rue Buffon, 75005 Paris (France)], E-mail: annamaria.quaranta@cea.fr; Zhang Yongmin [Universite Pierre and Marie Curie, Laboratoire de Chimie Organique, UMR 7611 CNRS, Tour 44/45, C. 181, 4 place Jussieu, 75005 Paris (France)], E-mail: yongmin.zhang@upmc.fr; Wang Yali [Universite Pierre and Marie Curie, Laboratoire de Chimie Organique, UMR 7611 CNRS, Tour 44/45, C. 181, 4 place Jussieu, 75005 Paris (France); Edge, Ruth [Free Radical Research Facility, STFC Daresbury Laboratory, Warrington, WA4 4AD, UK, and North East Wales Institute, Wrexham, LL11 2AW (United Kingdom); Free Radical Research Facility, STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Navaratnam, Suppiah [Free Radical Research Facility, STFC Daresbury Laboratory, Warrington, WA4 4AD, UK, and North East Wales Institute, Wrexham, LL11 2AW (United Kingdom); BioScience Research Institute, PEEL Building, University of Salford, Salford M5 4WT (United Kingdom); Land, Edward J. [Lennard-Jones Laboratories, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom); Bensasson, Rene V. [Laboratoire de Chimie et Biochimie des Substances Naturelles, MNHN, UMR5154 CNRS-MNHN/USM50502, 63 rue Buffon, 75005 Paris (France)], E-mail: rvb@mnhn.fr

    2008-12-10

    Spectroscopic and chemical properties of {gamma}-CD{sup {center_dot}} radicals, resulting from the abstraction by HO{sup {center_dot}} radicals of hydrogen atoms, have been investigated using pulse radiolysis. The reactions of {gamma}-CD{sup {center_dot}} radicals with C{sub 60} in 2:1 {gamma}-CD/C{sub 60} inclusion complexes have been studied in aqueous solutions. It has been demonstrated that the {gamma}-CD{sup {center_dot}} radicals are reducing species producing C{sub 60}{sup {center_dot}}{sup -} monoanion radicals, as well as doubly reduced C{sub 60}{sup 2-}, well characterised by their absorption spectra in the near IR. The oxidation potential of {gamma}-CD{sup {center_dot}} radical is estimated to be more negative than -390 mV vs. NHE. The kinetics of the C{sub 60} reduction by {gamma}-CD{sup {center_dot}} radicals have been determined and compared with kinetics by other reducing species including the solvated electron (e{sub aq}{sup -}) and CO{sub 2}{sup {center_dot}}{sup -} radicals. It was observed that the method of preparation of the 2:1 {gamma}-CD/C{sub 60} inclusion complexes modifies the C{sub 60} reduction mechanism.

  3. Determination of c{sub sw} in N{sub f}=3+1 lattice QCD with massive Wilson fermions

    Energy Technology Data Exchange (ETDEWEB)

    Stollenwerk, Felix

    2017-02-07

    In order to obtain sensible results from Lattice QCD that may be compared with experiment, extrapolation to the continuum is crucial. The well-established Symanzik improvement program systematically reduces the order of cutoff effects, allowing for better control of the aforementioned errors, as well as larger and thus more affordable lattice spacings. Applied to the Wilson fermion action, it entails the addition of the Sheikholeslami-Wohlert term with the O(a) improvement coefficient c{sub sw}. In this work, a strategy is developed for the non-perturbative determination of c{sub sw} in the theory with N{sub f}=3+1 massive sea quarks. It is embedded in a general, mass-dependent renormalization and improvement scheme, for which we lay the foundations. The improvement condition, formulated by means of the PCAC relation in the Schroedinger Functional, is imposed along a line of constant physics that is designed to be close to the physical mass of the charm quark. The aim of this rather elaborate approach is to avoid large, mass-dependent O(a{sup 2}) effects in future large volume simulations with four dynamical quark species. The numerical results are worked out using the tree-level improved Luescher-Weisz gauge action. Since the gradient flow coupling is employed in the definition of the line of constant physics, its interdependence with the topological charge in regard to critical slowing down and topology freezing is investigated in a supplemental study.

  4. Sputtering of Langmuir-Blodgett multilayers by keV C{sub 60} projectiles as seen by computer simulations

    Energy Technology Data Exchange (ETDEWEB)

    Paruch, R.; Rzeznik, L.; Czerwinski, B. [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow (Poland); Garrison, B.J.; Winograd, N. [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States); Postawa, Z. [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow (Poland)], E-mail: zp@castor.if.uj.edu.pl

    2009-08-15

    Fundamental processes induced in a thick organic system composed of long, well-organized linear molecules by an impact of 5-20 keV C{sub 60} are investigated. The organic system is represented by Langmuir-Blodgett multilayers formed from bariated molecules of arachidic acid. The thickness of the system varies between 2 and 16 nm. Coarse-grained molecular dynamics computer simulations are applied to investigate the energy transfer pathways and sputtering yields as a function of the kinetic energy of the projectile and the thickness of the organic overlayer. The results indicate that an impact of keV C{sub 60} projectiles leads to significant ejection of organic material. The efficiency of desorption increases with the kinetic energy of the projectile for a given layer thickness. For a constant primary kinetic energy, the sputtering yield goes through a maximum and finally saturates as the LB layer becomes thicker. Such behaviour is caused by a competition between signal enhancement due to increasing number of organic molecules and signal decrease due to lowering of the amount of the primary energy being backreflected into the organic overlayer by the receding organic/metal interface as the layer is getting thicker. When the sample thickness becomes much larger than the penetration depth of the projectile, the sputtering yield is independent of thickness. The deposited energy is channelled by an open and ordered molecular structure, which leads to abnormally long projectile penetration and ion-induced damage.

  5. The influence of C{sub s}/C{sub c} correction in analytical imaging and spectroscopy in scanning and transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zaluzec, Nestor J., E-mail: zaluzec@microscopy.com

    2015-04-15

    Aberration correction in scanning/transmission electron microscopy (S/TEM) owes much to the efforts of a small dedicated group of innovators. Leading that frontier has been Prof. Harald Rose. To date his leadership and dynamic personality has spearheaded our ability to leave behind many of the limitations imposed by spherical aberration (C{sub s}) in high resolution phase contrast imaging. Following shortly behind, has been the development of chromatic aberration correction (C{sub c}) which augments those accomplishments. In this paper we will review and summarize how the combination of C{sub s}/C{sub c} technology enhances our ability to conduct hyperspectral imaging and spectroscopy in today's and future computationally mediated experiments in both thin as well as realistic specimens in vacuo and during in-situ/environmental experiments.

  6. Stress relaxation in c {sub perpendicular} {sub to} -c{sub //} YBaCuO thin films on MgO substrate studied by LACBED

    Energy Technology Data Exchange (ETDEWEB)

    Pailloux, F.; Gaboriaud, R.J. [Poitiers Univ., 86 (France). Lab. de Metallurgie Physique

    2000-06-01

    Thin films of YBaCuO grown by in situ pulsed laser deposition on MgO substrate are studied by means of high resolution transmission electron microscopy imaging and large angle convergent beam electron diffraction experiments. Both c{sub //} and c {sub perpendicular} {sub to} YBaCuO crystals coexist in the film. The diffraction experiments are performed on the MgO substrate along the interface with the YBaCuO film. Some of the Bragg lines exhibit a dramatic broadening when the electron probe is just below the c{sub //} oriented crystal. This result is interpreted in terms of lattice strain relaxation due to the thinning of the TEM sample. This relaxation phenomenon indicates that the c{sub //} oriented grains embedded in a c {sub perpendicular} {sub to} oriented host matrix of YBaCuO, are under stress. (orig.)

  7. Sugar supported H/sub 2/ production and C/sub 2/H/sub 2/ reduction by the cyanobiont Anabaena azollae

    Energy Technology Data Exchange (ETDEWEB)

    Rozen, A.; Tel-Or, E.

    1986-01-01

    Sugar supported activities of H/sub 2/ production and C/sub 2/H/sub 2/ reduction were characterized in axenic cell cultures of the cyanobiont Anabaena azollae isolated from the water fern Azolla filiculoides. Fructose was found to be the favoured substrate, enhancing activities in both the light and the dark even at relatively low concentrations of 0.5-1.0 mM. Higher concentrations of sucrose, (10-20mM) also supported H/sub 2/ production and C/sub 2/H/sub 2/ reduction, while glucose was less effective. Levels of H/sub 2/ production were always lower than those of C/sub 2/H/sub 2/ reduction. 13 references.

  8. Synthesis and deformation microstructure of Ti{sub 3}SiAl{sub 0.2}C{sub 1.8} solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Li Shibo [School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing 100044 (China)]. E-mail: shibo-li@sohu.com; Bei Guoping [School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Li Cuiwei [School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Ai Mingxing [School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Zhai Hongxiang [School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Zhou Yang [School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing 100044 (China)

    2006-12-15

    Solid solution Ti{sub 3}SiAl{sub 0.2}C{sub 1.8} was synthesized by sintering powder compacts containing Ti, Si, Al, and C with a mole ratio of 3:1:0.2:1.8 at 1550 deg. C for 5 min in Ar. X-ray diffraction and scanning electron microscopy were used to characterize the samples. The results show that nearly single solid solution was obtained except for the presence of a small amount of TiC. The observation from the fracture surface shows that delamination, kink band formation and crack deflection are prevalent features in the deformed Ti{sub 3}SiAl{sub 0.2}C{sub 1.8} grains. The crystal parameters for Ti{sub 3}SiAl{sub 0.2}C{sub 1.8} were analyzed and the multiple energy dissipation mechanisms were discussed.

  9. 用计算化学法探讨(Cl-+CH3Br→CH3Cl+Br-)SN2亲核取代反应的溶剂效应%A Computational Method for Solvent Effects on the(Cl-+CH3Br→CH3Cl+Br-)SN2 Nucleophilic Substitution Reaction

    Institute of Scientific and Technical Information of China (English)

    邢波

    2010-01-01

    本研究采用GAUSSIAN05 HF/6-31+G(d)计算方法讨论(Cl-+CH3Br→CH3Cl+Br-)SN2亲核取代反应在6种不同极性溶剂中的反应速率.溶剂分为极性和非极性两类.分别采用过渡态理论和SN2亲核取代反应溶剂效应理论,分别计算反应速率常数并加以对比,判断反应进行难易程度.计算中考虑了反应温度273.15K,1atm(标准状态)情况.还计算了标准状态下反应平衡常数,同时验证了由反应速率计算得出的结论.计算过程中采用GaussView 4.1搭建分子模型.

  10. Preparation and Characterization of cis- and trans-[Ir(tn)2Cl2]CF3SO3 and of [Ir(tn)3]Cl3 (tn=propane-1,3-diamine)

    DEFF Research Database (Denmark)

    Brorson, Michael; Galsbøl, Frode; Simonsen, Kim

    1998-01-01

    for the preparation of [Rh(tn)3]Cl3 in quantitative yield from Rh(thtp)3Cl3 is also given. The complexes were characterized by 1H and 13C NMR and by UV/VIS spectroscopy. The conformation of the six-membered chelate rings of [Ir(tn)3]3+ in the solid state was determined by single-crystal X-ray diffraction of [Ir(tn)3......] [Co(CN)6] x 5H2O. The three chelate rings all adopt the energetically favoured chair conformation; however, the overall idealized symmetry is C1. A comparative ligand field analysis, based on Gaussian resolution of the solution UV/VIS spectra for a number of homoleptic [M(N6)]3+ (M=CoIII, RhIII, Ir...

  11. Preparation and Characterization of cis- and trans-[Ir(tn)2Cl2]CF3SO3 and of [Ir(tn)3]Cl3 (tn=propane-1,3-diamine)

    DEFF Research Database (Denmark)

    Brorson, Michael; Galsbøl, Frode; Simonsen, Kim;

    1998-01-01

    for the preparation of [Rh(tn)3]Cl3 in quantitative yield from Rh(thtp)3Cl3 is also given. The complexes were characterized by 1H and 13C NMR and by UV/VIS spectroscopy. The conformation of the six-membered chelate rings of [Ir(tn)3]3+ in the solid state was determined by single-crystal X-ray diffraction of [Ir(tn)3......] [Co(CN)6] x 5H2O. The three chelate rings all adopt the energetically favoured chair conformation; however, the overall idealized symmetry is C1. A comparative ligand field analysis, based on Gaussian resolution of the solution UV/VIS spectra for a number of homoleptic [M(N6)]3+ (M=CoIII, RhIII, Ir...

  12. Structure of UC{sub 2} and U{sub 2}C{sub 3}:XRD, {sup 13}C NMR and EXAFS study

    Energy Technology Data Exchange (ETDEWEB)

    Carvajal Nuñez, U. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Eloirdi, R., E-mail: rachel.eloirdi@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Prieur, D.; Martel, L. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); López Honorato, E. [Centro de Investigatión y de Estudios Avanzados del IPN (CINVESTAV), Unidad Saltillo, Av. Industria Metalúrgica 1062, Ramos Arizpe, Coahuila 25900 (Mexico); Farnan, I. [University of Cambridge, Cambridge CB2 1TN (United Kingdom); Vitova, T. [Institut für Nukleare Entsorgung (INE), P.O. Box 3640, D- 76021 Karlsruhe (Germany); Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany)

    2014-03-15

    Highlights: • A structural investigation of UC{sub 2} and U{sub 2}C{sub 3} phases was made with XRD, NMR and EXAFS. • Heat treatment of a pulverised UC{sub 2} ingot, repressed into a pellet yields a U{sub 2}C{sub 3} phase coexisting with UC{sub 2−z}. • Heat treatment of UC{sub 2} as cast ingots results in a partial decomposition to UC. • EXAFS data confirmed the CaC{sub 2} and Pu{sub 2}C{sub 3} type structure for UC{sub 2} and U{sub 2}C{sub 3} respectively. • {sup 13}C MAS NMR identified a contribution of a well and less ordered phases in UC{sub 2}. -- Abstract: In this study, uranium dicarbide (UC{sub 2}) has been prepared by arc melting and heat treated under vacuum to form uranium sequicarbide (U{sub 2}C{sub 3}) in the presence of a second phase UC{sub 2−z}. Both samples, as cast and heat treated, have been characterised by chemical analyses, X-ray diffraction (XRD), {sup 13}C magic angle spinning nuclear magnetic resonance (MAS-NMR) and by extended X-ray absorption fine structure (EXAFS). The composition, the purity, the various environments of both U and C atoms as well as the bonds length with the coordination number have been determined. By combining a long-range order method (XRD) and short-range order spectroscopy techniques (EXAFS and NMR), a unique view on the microstructure of UC{sub 2}, before and after heat treatment, and of U{sub 2}C{sub 3} phase has been achieved.

  13. Stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O from measurements made by the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    A. T. Brown

    2013-07-01

    Full Text Available Long lived halogen-containing compounds are important atmospheric constituents since they can act both as a source of chlorine radicals, which go on to catalyse ozone loss, and as powerful greenhouse gases. The long-term impact of these species on the ozone layer is dependent on their stratospheric lifetimes. Using observations from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS we present calculations of the stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O. The lifetimes were calculated using the slope of the tracer–tracer correlation of these species with CFC-11 at the tropopause. The correlation slopes were corrected for the changing atmospheric concentrations of each species based on age of air and CFC-11 measurements from samples taken aboard the Geophysica aircraft – along with the effective linear trend of the volume mixing ratio (VMR from tropical ground based AGAGE (Advanced Global Atmospheric Gases Experiment sites. Stratospheric lifetimes were calculated using a CFC-11 lifetime of 45 yr. These calculations produced values of 113 + (− 26 (18 yr (CFC-12, 35 + (− 11 (7 yr (CCl4, 69 + (− 65 (23 yr (CH3Cl, 123 + (− 53 (28 yr (N2O and 195 + (− 75 (42 yr (CH4. The errors on these values are the weighted 1σ non-systematic errors. Systematic errors were estimated by recalculating lifetimes using VMRs which had been modified to reflect differences between ACE-FTS retrieved VMRs and those from other instruments. The results of these calculations, including systematic errors, were as follows: 113 + (− 32 (20 for CFC-12, 123 + (− 83 (35 for N2O, 195 + (− 139 (57 for CH4, 35 + (− 14 (8 for CCl4 and 69 + (− 2119 (34 yr for CH3Cl. For CH3Cl & CH4 this represents the first calculation of the stratospheric lifetime using data from a space based instrument.

  14. Fractalkine/CX3CL1 induced intercellular adhesion molecule-1-dependent tumor metastasis through the CX3CR1/PI3K/Akt/NF-?B pathway in human osteosarcoma

    OpenAIRE

    Liu, Ju-Fang; Tsao, Ya-Ting; Hou, Chun-Han

    2016-01-01

    Osteosarcoma is the most common primary bone tumor in children and teens. The exact molecular mechanism underlying osteosarcoma progression still remains unclear. The CX3CL1/fractalkine has been implicated in various tumors but not in osteosarcoma. This study is the first to show that fractalkine promotes osteosarcoma metastasis by promoting cell migration. Fractalkine expression was higher in osteosarcoma cell lines than in normal osteoblasts. Fractalkine induced cell migration by upregulati...

  15. Rheological properties of gamma irradiated [Me3NC2H4OH]+[Zn2Cl5]- and [Me3NC2H4OH]+[Zn3Cl7]- ionic liquids

    Institute of Scientific and Technical Information of China (English)

    李倩妹; 罗迎社; 吴国忠; 陈仕谋

    2008-01-01

    The objective of this work is to verify the rheological behavior of irradiated [Me3NC2H4OH]+[Zn2Cl5]-and [Me3NC2H4OH]+[Zn3Cl7]-ionic liquids in comparison to the unirradiated ones,the viscosities were measured by a strain-control experiment under different irradiation doses’ samples(0,10,20,50,100 kGy) at different shear rates and temperatures.The curves of shear stress against shear rate present that the viscosity of ionic liquid is insensitive to shear rate;the viscosity of ionic liquids decreases with increasing temperature,and can be fitted by Arrhenius equation very well.Gamma radiation causes a decrease of viscosity of [Me3NC2H4OH]+[Zn3Cl7]-by greater than 10%,but it does not impair the viscosity of [Me3NC2H4OH]+[Zn2Cl5]-(within the experimental error) except 20 kGy irradiated sample.The results show that the radiation stability of [Me3NC2H4OH]+[Zn2Cl5]-is higher than that of [Me3NC2H4OH]+[Zn3Cl7]-.

  16. Chemotaxonomic significance of distribution and stable carbon isotopic composition of long-chain alkanes and alkan-1-ols in C{sub 4} grass waxes

    Energy Technology Data Exchange (ETDEWEB)

    Rommerskirchen, F.; Plader, A. [Carl von Ossietzky University, Oldenburg (Germany). Institute of Chemistry and Biology of the Marine Environment; Eglinton, G. [Hanse Institute for Advanced Study, Delmenhorst (Germany); Chikaraishii, Yoshito [Japan Agency for Marine-Earth Science and Technology, Yokosuka (Japan). Institute for Research on Earth Evolution

    2006-10-15

    Grasses (Poaceae) are distributed across the world in broad latitudinal belts and are an important source of C4 biomass in the geological record of soils as well as lake and marine sediments. We examined long-chain leaf wax components of thirty-five C{sub 4} grasses of the subfamilies Aristidoideae, Chloridoideae and Panicoideae from the southern African grasslands and savannas and three C{sub 3} grasses of the subfamily Pooideae from Peru and Australia and review the relevant botanical, phytogeographic and leaf wax compositional background information. Contents, distribution patterns and molecular stable carbon isotopic compositions of long-chain n-alkanes (n-C{sub 27} to n-C{sub 35}) and n-alkan-1-ols (n-C{sub 22} to n-C{sub 32}) were used to estimate the chemotaxonomic relevance of wax signatures of whole plants, separately for different subfamilies and for members of the three C{sub 4} subtypes (NADP-ME, NAD-ME and PCK). Two grass species were separated into flower heads, leaves and stems and the parts analysed separately. Grass flowers contain remarkable amounts of short-chain n-alkanes, which may have a significant influence on the chemical signature of the whole plant, whereas n-alkanol distribution patterns exhibit no systematics. The stable carbon isotopic composition of both biomarker types in different plant parts is remarkably uniform. Chemotaxonomic differentiation was not possible on a species level based on whole plant samples, but was more successful for averages of subfamily and photosynthetic subtype data. Wax signatures of C{sub 4} grasses are generally distinguishable from those of C{sub 3} species by heavier isotopic values, higher contents of n-C{sub 31} and n-C{sub 33} alkanes and the abundance of the n-C{sub 32} n-alkanol, which is largely absent in C{sub 3} grass waxes. Especially the waxes of the NAD-ME and PCK C{sub 4}-subtype grasses, which thrive in extremely arid tropical and subtropical areas, contain high relative amounts of longer

  17. Theoretical and experimental investigation on the stability of C{sub n=1-6}H{sup -} and C{sub n=1-4}H{sub x}{sup +} clusters

    Energy Technology Data Exchange (ETDEWEB)

    Fantuzzi, Felipe [Universidade Federal do Rio de Janeiro, Instituto de Quimica, Departamento de Fisico-Quimica, Avenida Athos da Silveira Ramos, 149 Bloco A, 4 Degree-Sign andar CEP 21941-909 Cidade Universitaria, Rio de Janeiro, RJ (Brazil); Baptista, Leonardo, E-mail: leobap@gmail.com [Universidade do Estado do Rio de Janeiro, Faculdade de Tecnologia, Departamento de Quimica e Ambiental, Rodovia Presidente Dutra Km 298, Resende, RJ (Brazil); Rocha, Alexandre B. [Universidade Federal do Rio de Janeiro, Instituto de Quimica, Departamento de Fisico-Quimica, Avenida Athos da Silveira Ramos, 149 Bloco A, 4 Degree-Sign andar CEP 21941-909 Cidade Universitaria, Rio de Janeiro, RJ (Brazil); Silveira, E.F. da [Pontificia Universidade Catolica do Rio de Janeiro, Departamento de Fisica, 22451-900 Rio de Janeiro, RJ (Brazil)

    2013-01-02

    Highlights: Black-Right-Pointing-Pointer A theoretical and experimental study of ionic hydrocarbon clusters was performed. Black-Right-Pointing-Pointer More than 300 structures were examined and the results compared with mass spectra. Black-Right-Pointing-Pointer Theoretical predictions and experimental data are in good agreement. Black-Right-Pointing-Pointer The original sample does not influence the cluster abundance. Black-Right-Pointing-Pointer Careful systematic search is important to reach the global minimum of clusters. -- Abstract: A theoretical study on the molecular structure of C{sub n}H{sup -} clusters, where 1 Less-Than-Or-Slanted-Equal-To n Less-Than-Or-Slanted-Equal-To 6, and C{sub n}H{sub x}{sup +} clusters, where 1 Less-Than-Or-Slanted-Equal-To n Less-Than-Or-Slanted-Equal-To 4 and 0 Less-Than-Or-Slanted-Equal-To x Less-Than-Or-Slanted-Equal-To 2n + 2, has been performed at the DFT level. More than 300 configurations were examined and their total electronic energies ordered for each cluster mass. The D-plot methodology was employed for classifying different structures into cluster families and identifying the most stable structures. For each family, the binding energies of the analyzed cluster species have been determined and displayed as a function of the cluster mass. The fluctuations of these curves are then compared to experimental data, namely, to the dependence of relative ion desorption yields on cluster mass, obtained from Plasma Desorption Mass Spectroscopy (PDMS) of quite distinct types of organic samples: solid methane, cholesterol and pump oil vapor adsorbed on polycrystalline LiF. It is found that theoretical predictions and experimental data are in good agreement, showing that the abundance of the emitted small cluster ions is determined by their own structure and not by the structure of the original sample.

  18. Photochemistry in a 3D metal-organic framework (MOF): monitoring intermediates and reactivity of the fac-to-mer photoisomerization of Re(diimine)(CO)3Cl incorporated in a MOF.

    Science.gov (United States)

    Easun, Timothy L; Jia, Junhua; Calladine, James A; Blackmore, Danielle L; Stapleton, Christopher S; Vuong, Khuong Q; Champness, Neil R; George, Michael W

    2014-03-03

    The mechanism and intermediates in the UV-light-initiated ligand rearrangement of fac-Re(diimine)(CO)3Cl to form the mer isomer, when incorporated into a 3D metal-organic framework (MOF), have been investigated. The structure hosting the rhenium diimine complex is a 3D network with the formula {Mn(DMF)2[LRe(CO)3Cl]}∞ (ReMn; DMF = N,N-dimethylformamide), where the diimine ligand L, 2,2'-bipyridine-5,5'-dicarboxylate, acts as a strut of the MOF. The incorporation of ReMn into a KBr disk allows spatial distribution of the mer-isomer photoproduct in the disk to be mapped and spectroscopically characterized by both Fourier transform infrared and Raman microscopy. Photoisomerization has been monitored by IR spectroscopy and proceeds via dissociation of a CO to form more than one dicarbonyl intermediate. The dicarbonyl species are stable in the solid state at 200 K. The photodissociated CO ligand appears to be trapped within the crystal lattice and, upon warming above 200 K, readily recombines with the dicarbonyl intermediates to form both the fac-Re(diimine)(CO)3Cl starting material and the mer-Re(diimine)(CO)3Cl photoproduct. Experiments over a range of temperatures (265-285 K) allow estimates of the activation enthalpy of recombination for each process of ca. 16 (±6) kJ mol(-1) (mer formation) and 23 (±4) kJ mol(-1) (fac formation) within the MOF. We have compared the photochemistry of the ReMn MOF with a related alkane-soluble Re(dnb)(CO)3Cl complex (dnb = 4,4'-dinonyl-2,2'-bipyridine). Time-resolved IR measurements clearly show that, in an alkane solution, the photoinduced dicarbonyl species again recombines with CO to both re-form the fac-isomer starting material and form the mer-isomer photoproduct. Density functional theory calculations of the possible dicarbonyl species aids the assignment of the experimental data in that the ν(CO) IR bands of the CO loss intermediate are, as expected, shifted to lower energy when the metal is bound to DMF rather than to an

  19. Synthesis and luminescence properties of green phosphors Ca{sub 6}Sr{sub 4}(Si{sub 2}O{sub 7}){sub 3}Cl{sub 2}:Eu{sup 2+} for white light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Li Zhaomei [College of Chemistry and Chemical Engineering, Fuzhou University, Fujian Fuzhou 350108 (China); Gao Shaokang, E-mail: gaosk@fzu.edu.cn [College of Chemistry and Chemical Engineering, Fuzhou University, Fujian Fuzhou 350108 (China); Chen Xiuxia; Yu Qun [College of Chemistry and Chemical Engineering, Fuzhou University, Fujian Fuzhou 350108 (China)

    2012-06-15

    Divalent europium-activated chlorosilicate Ca{sub 6}Sr{sub 4}(Si{sub 2}O{sub 7}){sub 3}Cl{sub 2}:Eu{sup 2+} phosphors were synthesized by a conventional solid-state reaction under reductive atmosphere. These phosphors can be efficiently excited by UV-visible light from 320 to 420 nm, which matches that of a near UV-emitting InGaN chip. Under the 360 nm excitation, Ca{sub 6}Sr{sub 3.97}(Si{sub 2}O{sub 7}){sub 3}Cl{sub 2}:0.03Eu{sup 2+} phosphor shows a strong and broad emission centering at 515 nm, which is attributed to the 5d{yields}4f transition of Eu{sup 2+} ion. The mechanism of concentration quenching was determined to be the dipole-dipole interaction and the critical energy-transfer distance of Eu{sup 2+} was calculated as 3.31 nm. The CIE chromaticity coordinates of Ca{sub 6}Sr{sub 3.96}(Si{sub 2}O{sub 7}){sub 3}Cl{sub 2}:0.03Eu{sup 2+} phosphor are (0.127, 0.770) according to the emission spectrum. It can be expected that Ca{sub 6}Sr{sub 4}(Si{sub 2}O{sub 7}){sub 3}Cl{sub 2}:Eu{sup 2+} phosphor is a promising candidate as the green component for near-ultraviolet InGaN-based white LED. - Highlights: Black-Right-Pointing-Pointer Ca{sub 6}Sr{sub 4}(Si{sub 2}O{sub 7}){sub 3}Cl{sub 2}:Eu{sup 2+} phosphor was synthesized by solid-state reactions. Black-Right-Pointing-Pointer This phosphor can be effectively excited by ultraviolet light from 320 to 420 nm. Black-Right-Pointing-Pointer It exhibits a strong and broad band green emission excited at 360 nm. Black-Right-Pointing-Pointer Dipole-dipole interaction is the major mechanism of concentration quenching of Eu{sup 2+}. Black-Right-Pointing-Pointer The phosphor is a promising green component for NUV InGaN-based white LED.

  20. Photolytic production of C/sup 2/H: collisional quenching of A tilde /sup 2/II. -->. X tilde /sup 2/Sigma/sup +/ infrared emission and the removal of excited C/sub 2/H

    Energy Technology Data Exchange (ETDEWEB)

    Shokoohi, F.; Watson, T.A.; Reisler, H.; Kong, F.; Renlund, A.M.; Wittig, C.

    1986-10-23

    The authors report the observation of time-resolved C/sub 2/H A tilde /sup 2/II ..-->.. X tilde /sup 2/Sigma/sup +/ infrared emission (1-5 ..mu..m) following the 193-nm photolyses of C/sub 2/H/sub 2/ and C/sub 2/HBr. Quenching of this emission by numerous collision partners (M) under pseudo-first-order conditions leads to large bimolecular rate coefficients (e.g. > 10/sup -11/ cm/sup 3/ molecule/sup -1/ s/sup -1/, except when M is a rare gas or N/sub 2/). Although such rate coefficients can be assigned to the quenching of fluorescence, they do not represent state-to-state processes, since quenching is due to an intricate combination of reactive, radiative, and energy-transfer processes. In separate experiments, rate coefficients are determined by monitoring the time-resolved CH A/sup 2/..delta.. ..-->.. X/sup 2/II chemiluminescence which is produced directly by the reaction of C/sub 2/H with O/sub 2/, and the C/sub 2/H species responsible for the CH emissions is identified as electronically and/or vibrationally excited C/sub 2/H. The above results are in agreement with recent molecular beam experiments that show that nascent C/sub 2/H contains considerably internal energy following the 193-nm photolysis of C/sub 2/H/sub 2/.

  1. Nanomechanical properties of SiC films grown from C{sub 60} precursors using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Morse, K. [Colorado School of Mines, Golden, CO (United States); Balooch, M.; Hamza, A.V.; Belak, J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-01

    The mechanical properties of SiC films grown via C{sub 60} precursors were determined using atomic force microscopy (AFM). Conventional silicon nitride and modified diamond cantilever AFM tips were employed to determine the film hardness, friction coefficient, and elastic modulus. The hardness is found to be between 26 and 40 GPa by nanoindentation of the film with the diamond tip. The friction coefficient for the silicon nitride tip on the SiC film is about one third that for silicon nitride sliding on a silicon substrate. By combining nanoindentation and AFM measurements an elastic modulus of {approximately}300 GPa is estimated for these SiC films. In order to better understand the atomic scale mechanisms that determine the hardness and friction of SiC, we simulated the molecular dynamics of a diamond indenting a crystalline SiC substrate.

  2. Nonvolatile memory devices based on ZnO/polyimide nanocomposite sandwiched between two C{sub 60} layers

    Energy Technology Data Exchange (ETDEWEB)

    Li Fushan [Advanced Semiconductor Research Center, Division of Electronics and Computer Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Tae Whan, E-mail: twk@hanyang.ac.k [Advanced Semiconductor Research Center, Division of Electronics and Computer Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Dong Wenguo; Kim, Young-Ho [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2009-05-29

    The memory effects of a three-layer nonvolatile memory device Al/C{sub 60}/ZnO nanoparticles embedded in a polyimide (PI) layer/C{sub 60}/p-Si were investigated by using capacitance-voltage (C-V) measurements. Transmission electron microscopy and selected area electron diffraction pattern measurements showed that ZnO nanocrystals were formed inside the PI layer. The insertion of C{sub 60} layer improved the charge trap state density in the ZnO nanoparticle. The density was estimated by the flatband voltage shift in the C-V hysteresis, which increases with the max sweep voltage. Possible operating mechanisms corresponding to the charging and discharging process in the structure are proposed on the basis of the C-V results.

  3. Selectivity of oxazolidine derivatives in the separation of C/sub 5/ hydrocarbons with different degrees of saturation

    Energy Technology Data Exchange (ETDEWEB)

    Apter, Yu.M.; Gaile, A.A.; Proskuryakov, V.A.; Semenov, L.V.

    1980-01-01

    An increase in the selectivity of cyclic compound solvents in the separation of hydrocarbons of different degrees of saturation can be attained by reducing the size of the ring and introducing an additional heteroatom into the ring. In connection with this, the selectivity of oxazolidine derivatives, differing in respect to their structure from known extractants -- pyrrolidine derivatives -- by the presence of a second heteroatom in the ring and from morpholine derivatives by the smaller ring size was studied. It was found that oxazolidine derivatives show higher selectivity in respect to hydrocarbon systems than the corresponding pyrrolidine and morpholine derivatives. The dissolving capacity of oxazolidine derivatives in respect to unsaturated hydrocarbons is higher than that of isomeric compounds of the morpholine series. The values of the activity coefficients of the C/sub 5/ hydrocarbons at infinite dilution in polar solvents correlate satisfactorily with the ionization potentials of the hydrocarbons.

  4. Effects of spin doping and spin injection in the luminescence and vibrational spectrum of C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Moorsom, Timothy; Wheeler, May; Taukeer Khan, Mohd; Al Ma' Mari, Fatma; Burnell, Gavin; Hickey, Bryan J.; Cespedes, Oscar, E-mail: o.cespedes@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, LS2 9JT W. Yorkshire (United Kingdom); Lazarov, Vlado; Gilks, Daniel [Department of Physics, University of York, YO10 5DD N. Yorkshire (United Kingdom)

    2014-07-14

    We have studied the Raman spectrum and photoemission of hybrid magneto-fullerene devices. For C{sub 60} layers on cobalt, the spin polarized electron transfer shifts the photoemission energy, reducing the zero phonon contribution. The total luminescence of hybrid devices can be controlled via spin injection from magnetic electrodes, with changes of the order of 10%–20% at room temperature. Spin polarised currents alter as well the Raman spectrum of the molecules, enhancing some modes by a factor 5 while shifting others by several wavenumbers due to a spin-dependent hopping time and/or enhanced intermolecular interactions. These results can be used to measure spin polarisation in molecules or to fabricate magneto-optic and magneto-vibrational devices.

  5. A theoretical analysis of the reaction of H with C{sub 2}H{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Harding, L.B.; Klippenstein, S.J.

    1998-07-01

    The reaction of ethyl radicals with H atoms is of general importance in hydrocarbon combustion. The interaction of H with C{sub 2}H{sub 5} is analyzed at the CAS+1+2 level employing a correlation-consistent polarized valence double zeta basis set. These ab initio calculations show three barrierless pathways, two leading to association and one for abstraction. The association channels are substantially more attractive than the abstraction one, and thus dominate the kinetics. An analytic representation of the ab initio data is implemented in a variable reaction coordinate transition state theory study of the temperature dependence of the association kinetics. These theoretical estimates for the high pressure association rate constant are directly compared with related experimental measurements in an effort to resolve the discrepancy between recent and earlier results.

  6. Paleoenvironmental implications of novel C[sub 30] steranes in Precambrian to Cenozoic age petroleum and bitumen

    Energy Technology Data Exchange (ETDEWEB)

    McCaffrey, M.A.; Lipton, P.A. (Chevron Petroleum Technology Company, La Habra, CA (United States)); Moldowan, J.M. (Cheveron Petroleum Technology Company, Richmond, CA (United States) Stanford Univ., CA (United States)); Summons, R.E. (Australian Geological Survey Organization, Canberra City (Australia)); Peters, K.E. (Chevron Overseas Petroleum Inc., San Ramon, CA (United States) Mobil Exploration and Producing Technical Center, Dallas, TX (United States)); Jeganathan, A.; Watt, D.S. (Univ. of Kentucky, Lexington, KY (United States))

    1994-01-01

    Petroleums and bitumens from Early Proterozoic ([approx] 1800 Ma) to Miocene ([approx] 15 Ma) age marine strata contain 24-isopropylcholestanes, a novel group of C[sub 30] steroids. The abundance of these compounds, relative to 24-n-propylcholestanes, varies with source rock age. Late Proterozoic (Vendian) and Early Cambrian oils and/or bitumens from Siberia, the Urals, Oman, Australia, and India have a high ratio of 24-isopropylcholestanes to 24-n-propylcholestanes ([ge] 1), while younger and older samples have a low ratio ([le]0.4). Temporal changes in this parameter may reflect the relative abundance of certain Porifera (sponges) and certain Marine algae through time. Geochemical indicators such as this, which can constrain the source rock age of a migrated oil, are useful in source rock identification during petroleum exploration.

  7. Depth profiling of taxol-loaded poly(styrene-b-isobutylene-b-styrene) using Ga{sup +} and C{sub 60} {sup +} ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Braun, R.M. [Surface Science Laboratory, Bausch and Lomb Inc., Rochester, NY 14609 (United States)]. E-mail: rbraun@bausch.com; Cheng, J. [Department of Chemistry, Penn State University, University Park, PA 16802 (United States); Parsonage, E.E. [Boston Scientific Inc., Maple Grove, MN 55311-1566 (United States); Moeller, J. [Boston Scientific Inc., Maple Grove, MN 55311-1566 (United States); Winograd, N. [Department of Chemistry, Penn State University, University Park, PA 16802 (United States)

    2006-07-30

    The surface of a triblock copolymer, containing a solid-phase drug, was investigated using 15 keV Ga{sup +} and 20 keV C{sub 60} {sup +} ion beams. Overall, the results illustrate the successful use of a cluster ion beam for greatly enhancing the molecular ion and high-mass fragment ion intensities from the surface and bulk of the polymer system. The use of C{sub 60} {sup +} also established the ability to see through common overlayers like poly(dimethyl siloxane) which was not possible using atomic ion sources. Moreover, the use of C{sub 60} {sup +} allowed depth profiles to be obtained using primary ion dose densities in excess of 6 x 10{sup 14} C{sub 60} {sup +}/cm{sup 2}. Resulting sputter craters possess relatively flat bottoms without the need for sample rotation and reached depths of ca. 2 {mu}m. AFM results illustrate the more gentile removal of surface species using cluster ions. Specifically, phase contrast and topographic images suggest the relatively high ion doses do not significantly alter the phase distribution or surface topography of the polymer. However, a slight increase in rms roughness was noticed.

  8. Biosynthesis of 24-methylsterols from (1,2-/sup 13/C/sub 2/) acetate; dihydrobrassicasterol and campesterol in tissue cultures of Physalis peruviana and ergosterol in yeast

    Energy Technology Data Exchange (ETDEWEB)

    Seo, S.; Uomori, A.; Yoshimura, Y.; Takeda, K. (Shionogi and Co. Ltd., Osaka (Japan). Research Lab.)

    1984-09-01

    The /sup 13/C labelling patterns of the two methyl groups at C-25 of dihydrobrassicasterol biosynthesized from (1,2-/sup 13/C/sub 2/) acetate differ from those of campesterol and 24-methylenecholesterol obtained from cultured cells of Physalis peruviana and ergosterol from yeast.

  9. In situ nonlinear optical spectroscopy of electron-phonon couplings at alkali-doped C{sub 60}/Ag(111) interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kakudji, Ernest [Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), B-5000 Namur (Belgium); Physics Department, University of Kinshasa (UNIKIN), Kinshasa (CD); Silien, Christophe [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Lis, Dan; Cecchet, Francesca; Thiry, Paul A.; Peremans, Andre; Caudano, Yves [Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), B-5000 Namur (Belgium); Nouri, Abdelkader [Laboratoire Materiaux, Ecole Normale Superieure d' Enseignement Technique (ENSET), Oran 31000 (Algeria)

    2010-08-15

    We use doubly resonant, infrared-visible sum-frequency generation spectroscopy (DR-SFG) to probe vibrational and electronic properties of C{sub 60} and K-doped C{sub 60} monolayers adsorbed on Ag(111) single crystal under ultra-high vacuum (UHV). We recorded the interface SFG spectra for five visible wavelengths. We observe a strong dependence of the SFG intensity of the totally symmetric A{sub g}(2) mode of the fullerene while scanning the visible wavelength, due to the DR-SFG phenomenon. The SFG intensity of the A{sub g}(2) mode is the strongest at 488 nm and at 532 nm for the pure and fully doped monolayers, respectively. These results demonstrate the occurrence of electron-phonon couplings at the C{sub 60}/Ag(111) and saturated K/C{sub 60}/Ag(111) interfaces. They enable us to determine the energy of the coupled electronic transition and to link the electronic resonance to the h{sub u} (HOMO) to t{sub 1g} (LUMO + 1) transition of C{sub 60}. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  10. Modified growth of Ge quantum dots using C{sub 2}H{sub 4} mediation by ultra-high vacuum chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.W. [Institute of Materials Science and Engineering, National Central University, Jhong-Li 32001, Taiwan (China)], E-mail: swlee@ncu.edu.tw; Chen, P.S. [Department of Materials Science and Engineering, Minghsin University of Science and Technology, Hsinchu 30401, Taiwan (China); Cheng, S.L. [Institute of Materials Science and Engineering, National Central University, Jhong-Li 32001, Taiwan (China); Department of Chemical and Materials Engineering, National Central University, Jhong-Li 32001, Taiwan (China); Lee, M.H. [Institute of Electro-optical Science and Technology, National Taiwan Normal University, Taipei 11677, Taiwan (China); Chang, H.T. [Institute of Materials Science and Engineering, National Central University, Jhong-Li 32001, Taiwan (China); Lee, C.-H.; Liu, C.W. [Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2008-07-30

    C{sub 2}H{sub 4} mediations were used to modify the Stranski-Krastanow growth mode of Ge dots on Si(0 0 1) at 550 deg. C by ultra-high vacuum chemical vapor deposition. With appropriate C{sub 2}H{sub 4}-mediation to modify the Si surface, the elongated Ge hut clusters can be transformed to highly uniform Ge domes with a high Ge composition at the core. These C{sub 2}H{sub 4}-mediated Ge dots, almost bounded by {l_brace}1 1 3{r_brace} facets, have an average diameter and height of 55 and 9 nm, respectively. We propose two major mechanisms to depict the formation of these C{sub 2}H{sub 4}-mediated Ge dots: (i) an almost hydrogen-passivated Si surface to limit the nucleation sites for dot formation, and (ii) the incorporation of Ge atoms, repelled by the C-rich areas, into the existing Ge dots. This work provides a useful scheme to tune the topography of Ge dots in an UHV/CVD condition for possible optoelectronic applications.

  11. Microstructure and microhardness characterization of Cr{sub 3}C{sub 2}-SiC coatings produced by the plasma transferred arc method

    Energy Technology Data Exchange (ETDEWEB)

    Islak, Serkan [Kastamonu Univ. (Turkey). Cide Rifat Ilgaz Vocational High School; Eski, Oezkan [Kastamonu Univ. (Turkey). Kastamonu Vocational High School; Buytoz, Soner [Firat Univ., Elazig (Turkey). Dept. of Metallurgy and Materials Engineering; Karagoez, Muzaffer [Bartin Univ. (Turkey). Dept. of Metallurgical and Materials Engineering; Stokes, Joseph [Dublin City Univ. (Ireland). School of Mechanical and Manufacturing Engineering

    2012-07-01

    The purpose of this work was to investigate the coatings made of Cr{sub 3}C{sub 2} and SiC powder manufactured on AISI 304 stainless steel applied by the plasma transferred arc (PTA) welding process. SiC content in the produced coated layer was varied between 0-100 wt. % and the effect of SiC concentration on the microstructure and hardness of the coating was measured experimentally. SEM analyses revealed that the composite coatings had a homogeneous, nonporous, and crack-free microstructure. Dendrites and interdendrite eutectics formed on the coating layer, subject to the temperature gradient and the solidification ratio. There was a significant increase in the hardness of coating layers with the effect of the {gamma}-(Fe,Ni), Cr{sub 7}C{sub 3}, Cr{sub 23}C{sub 6}, Fe{sub 5}C{sub 2}, Cr{sub 3}Si, CrSi{sub 2}, Fe{sub 0.64}Ni{sub 0.36}, CFe{sub 15.1}, C-(Fe,Cr)-Si phases formed in the microstructure. In comparison to the substrate, the microhardness of the coatings produced by PTA were 2.5-3.5 times harder. (orig.)

  12. Microstructural and superconducting properties of C{sub 6}H{sub 6} added bulk MgB{sub 2} superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Babaoglu, Meral G.; Safran, Serap; Cicek, Oezlem; Ag Latin-Small-Letter-Dotless-I l, Hasan; Ertekin, Ercan [Department of Physics, Faculty of Science, Ankara University, Tandogan 06100, Ankara (Turkey); Hossain, Md.Shahriar A. [Institute for Superconducting and Electronic Materials, University of Wollongong, Innovation Campus, North Wollongong, NSW 2519 (Australia); Yanmaz, Ekrem [Department of Physics, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Gencer, Ali, E-mail: gencer@science.ankara.edu.tr [Department of Physics, Faculty of Science, Ankara University, Tandogan 06100, Ankara (Turkey)

    2012-10-15

    The effect of aromatic hydrocarbon (benzene, C{sub 6}H{sub 6}) addition on lattice parameters, microstructure, critical temperature (T{sub c}), critical current density (J{sub c}) of bulk MgB{sub 2} has been studied. In this work only 2 mol% C{sub 6}H{sub 6} addition was found to be very effective in increasing the J{sub c} values, while resulting in slight reduction of the T{sub c}. J{sub c} values of 2 mol% C{sub 6}H{sub 6} added MgB{sub 2} bulks reached to 1.83 Multiplication-Sign 10{sup 6} A/cm{sup 2} at 15 K and 0 T. Microstructural analyses suggest that J{sub c} enhancement is associated with the substitution of carbon with boron and which also results in the smaller MgB{sub 2} grain size. The change in the lattice parameters or the lattice disorder is claimed as a cause of the slight reduction in the T{sub c} by carbon addition. We note that our results show the advantages of C{sub 6}H{sub 6} addition include homogeneous mixing of precursor powders, avoidance of expansive nanoadditives, production of highly reactive C, and significant enhancement in J{sub c} of MgB{sub 2}, compared to un-doped samples.

  13. Comparing study of high temperature erosion of HVOF sprayed Cr{sub 3}C{sub 2}-NiCr coating and mild steel for boiler tube

    Energy Technology Data Exchange (ETDEWEB)

    Yang, G.; Zhang, S.; Wang, Y.; Li, C.; Li, C. [Xi' an Jiaotong Univ., Xi' an (China)

    2008-07-01

    The significant erosion of the boiler tube at high temperature becomes an important problem for the safe operation of circulating fluidized bed boiler. This paper investigated the erosion behavior of the HVOF sprayed Cr{sub 3}C{sub 2}-NiCr coating at high temperature comparing with the typical mild steel for boiler tube. Results showed that the erosion rate of the mild steel increased with the increase of temperature. The erosion rate of the mild steel at 800 C was 4 times that at 300 C at an erosion angle of 30 . However, the erosion rate of the HVOF sprayed Cr{sub 3}C{sub 2}-NiCr coating was not influenced by the temperature in the range of 300 to 800 C. It is found that the erosion resistance of HVOF sprayed Cr{sub 3}C{sub 2}-NiCr coating was more than 3 time higher than that of the mild steel at 700 to 800 C. In addition to the ploughing on the surface of the worn coating, the cracking along splats interfaces in the coating was clearly observed on the cross-sectional microstructure of the coating. The results indicate that the erosion performance of the HVOF sprayed Cr{sub 3}C{sub 2}-NiCr coating is controlled by the cohesion between splats in the coating and can be further enhanced by improving splat cohesion. (orig.)

  14. Suspended C{sub 60} nanoparticles protect against short-term UV and fluoranthene photo-induced toxicity, but cause long-term cellular damage in Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X.Y. [Department of Zoology, Miami University, Oxford, OH 45056 (United States); Edelmann, R.E. [Electron Microscopy Facility, Miami University, Oxford, OH 45056 (United States); Oris, J.T., E-mail: orisjt@muohio.edu [Department of Zoology, Miami University, Oxford, OH 45056 (United States)

    2010-10-15

    The increased production of nanotechnology materials is a potential source of nano-sized particles (NSPs) in aquatic ecosystems. Meanwhile, polycyclic aromatic hydrocarbons (PAHs), in the presence of ecologically relevant levels of ultraviolet radiation (UV), can be acutely toxic to aquatic species including fish and invertebrates. Considering that suspended carbon-based NSPs (e.g., C{sub 60} fullerenes) may act in similar ways as dissolved organic matter (DOM) by altering the bioavailability of PAHs, the objective of this research was to determine the effect of suspended C{sub 60} on the photo-induced toxicity of fluoranthene. Transmission electron microscopy indicated that the presence of C{sub 60} protected cellular components (e.g., mitochondria, microvilli, and basal infoldings) in organisms exposed to UV and fluoranthene phototoxicity in short-term exposures. However, we found that long-term exposure (21 d) of low-level C{sub 60} caused significant cellular damage in the Daphnia magna alimentary canal. This paper highlights the importance of examining the interactions between existing stressors and nanoparticles in the aquatic environment.

  15. Bacterial and human cell mutagenicity study of some C[sub 18]H[sub 10] cyclopenta-fused polycyclic aromatic hydrocarbons associated with fossil fuels combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lafleur, A.L.; Longwell, J.P.; Marr, J.A.; Monchamp, P.A.; Thilly, W.G. (Massachusetts Institute of Technology, Cambridge (United States)); Mulder, P.P.Y.; Boere, B.B.; Cornelisse, J.; Lugtenburg, J. (Univ. of Leiden (Netherlands))

    1993-06-01

    A number of isomeric C[sub 18]H[sub 10] polycyclic aromatic hydrocarbons (PAHs), thought to be primarily cyclopenta-fused PAHs, are produced during the combustion and pyrolysis of fossil fuels. To determine the importance of their contributions to the total mutagenic activity of combustion and pyrolysis samples in which they are found, we characterized reference quantities of four C[sub 18]H[sub 10] CP-PAHs: benzol [ghi] fluoranthene (BF), cyclopenta [cd] pyrene (CPP), cyclopent [hi] acephenanthrylene (CPAP), and cyclopent [hi] acaenthrylene (CPAA). Synthesis of CPAA and CPAP is described. The availability of reference samples of these isomers also proved to be an essential aid in the identification of the C[sub 18]H[sub 10] species often found in combustion and pyrolysis samples. Chemical analysis of selected combustion and pyrolysis samples showed that CPP was generally the most abundant C[sub 18]H[sub 10] isomer, followed by CPAP and BF. CPAA was detected only in pyrolysis products from pure PAHs. We tested the four C[sub 18]H[sub 10] PAHs for mutagenicity in a forward mutation assay using S. typhimurium. CPP, BF, and CPAA were roughly twice as mutagenic as benzo[a]pyrene (BaP), whereas CPAP was only slightly active. These PAHs were also tested for mutagenic activity in human cells. In this assay, CPP and CPAA were strongly mutagenic but less active than BaP, whereas CPAP and BF were inactive at the dose levels tested. Also, the bacterial and human cell mutagenicity of CPAA and CPAP were compared with the mutagenicity of their monocyclopenta-fused analogs, aceanthrylene and acephenanthrylene. Although the mutagenicities of CPAP and acephenanthrylene are similar, the mutagenic activity of CPAA is an order of magnitude greater than that of aceanthrylene.

  16. Comparative study of Cr{sub 3}C{sub 2}-NiCr coatings obtained by HVOF and hard chromium coatings

    Energy Technology Data Exchange (ETDEWEB)

    Guilemany, J.M. [CPT Thermal Spray Centre, Materials Engineering, Dept. Ciencia de Materiales e Ingenieria Metalurgica, Universidad de Barcelona, C/Marti i Franques 1, CP 08028 Barcelona (Spain)]. E-mail: cpt-cmem@ub.edu; Espallargas, N. [CPT Thermal Spray Centre, Materials Engineering, Dept. Ciencia de Materiales e Ingenieria Metalurgica, Universidad de Barcelona, C/Marti i Franques 1, CP 08028 Barcelona (Spain); Suegama, P.H. [CPT Thermal Spray Centre, Materials Engineering, Dept. Ciencia de Materiales e Ingenieria Metalurgica, Universidad de Barcelona, C/Marti i Franques 1, CP 08028 Barcelona (Spain); Dep. Fisico-Quimica, Instituto de Quimica, Universidade Estadual Paulista, UNESP, CP 355, 14801-970 Araraquara, SP (Brazil); Benedetti, A.V. [CPT Thermal Spray Centre, Materials Engineering, Dept. Ciencia de Materiales e Ingenieria Metalurgica, Universidad de Barcelona, C/Marti i Franques 1, CP 08028 Barcelona (Spain) and Dep. Fisico-Quimica, Instituto de Quimica, Universidade Estadual Paulista, UNESP, CP 355, 14801-970 Araraquara, SP (Brazil)]. E-mail: benedeti@iq.unesp.br

    2006-10-15

    In the present work the corrosion resistance of micro-cracked hard chromium and Cr{sub 3}C{sub 2}-NiCr (HVOF) coatings applied on a steel substrate have been compared using open-circuit potential (E {sub OC}) measurements, electrochemical impedance spectroscopy (EIS) and polarization curves. The coatings surfaces and cross-section were characterized before and after corrosion tests using optical microscopy (OM) and scanning electron microscopy (SEM). After 18 h of immersion, the open-circuit potential values were around -0.50 and -0.25 V/(Ag vertical bar AgCl vertical bar KCl{sub sat}) for hard chromium and Cr{sub 3}C{sub 2}-NiCr, respectively. The surface analysis done after 12 h of immersion showed iron on the hard chromium surface inside/near surface cracks, while iron was not detected on the Cr{sub 3}C{sub 2}-NiCr surface even after 18 h. For longer immersion time hard chromium was more degraded than thermal sprayed coating. For hard chromium coating a total resistance values between 50 and 80 k{omega} cm{sup 2} were measured and two well-defined time constants were observed, without significant change with the immersion time. For Cr{sub 3}C{sub 2}-NiCr coating the total impedance diminished from around 750 to 25 k{omega} cm{sup 2} as the immersion time increased from 17 up to 132 h and two overlapped time constants were also observed. Polarization curves recorded after 18 h of immersion showed a lower current and higher corrosion potential for Cr{sub 3}C{sub 2}-NiCr coating than other samples studied.

  17. Formation of nano-crystalline C{sub 3}N{sub 4} thin films on stainless steel from hexamethylenetetramine and urea using simple sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, Md. Nizam, E-mail: nizam3472@yahoo.com [Department of Chemistry, Shahjalal University of Science and Technology, Sylhet-3114 (Bangladesh); Yang, Yong Suk, E-mail: ysyang@pusan.ac.kr [College of Nanoscience and Nanotechnology, RCDAMP, Pusan National University, Pusan 609-735 (Korea, Republic of)

    2013-12-02

    Nano-crystalline C{sub 3}N{sub 4} thin films have been deposited on stainless steel (SS) substrates from hexamethylenetetramine (HMTA) and urea separately using simple sol–gel method. For that purpose hot-dip coating processes were carried out. The coated specimens were annealed at 800 °C in N{sub 2}. The samples were analyzed using field emission scanning electron microscopy, nanoindenter, X-ray photoelectron spectroscopy and X-ray diffraction. The deposits show C{sub 3}N{sub 4} with clear hexagonal morphology and size range of 50–500 nm. The hardness values of the synthesized films show 2.74–4.35 times higher than that of SS. The hardness and Young's modulus of the films synthesized from HMTA show the highest values; 16.10 and 394.29 GPa, respectively. This significant achievement of the production of nano-crystalline C{sub 3}N{sub 4} from inexpensive sources and simple methods at ambient pressure opens up a door for its low cost production on SS for a wide range of applications. Irrespective of the sources with different chemical structures we got similar product, which implies that different sources of carbon and nitrogen might be used with our methods of sol–gel deposition. - Highlights: • Formation of nano-crystalline C{sub 3}N{sub 4} thin films with a low cost and simple sol–gel method • Uses of inexpensive materials, like steel, hexamethylenetetramine and urea • Repeatability of this method using different precursors for crystalline C{sub 3}N{sub 4} thin films.

  18. Magnetic field induced absorption of zero-phonon lines in (Ru(bpy)3)(PF6)2 and (Ru(bpy)3)(ClO4)2 single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hensler, G.; Gallhuber, E.; Yersin, H.

    1987-06-03

    In recent studies they have investigated the spectroscopic properties of (Ru(bpy)3)X2 single crystals (with X = PF6 and ClO4 and bpy = 2,2'-bipyridine). In particular, it was possible to discover sharp, purely electronic (zero-phonon) transitions corresponding to the two lowest excited states in the emission spectra of (Ru(bpy)3)(ClO4)2 and (Ru(bpy)3)(PF6)2. They communicate here the observation of the corresponding zero-phonon lines also in the absorption spectra and report on changes of the absorption under application of high magnetic fields.

  19. 3C和3CL蛋白酶及广谱抑制剂的研究进展%Broad spectrum inhibitors of 3C and 3CL proteases:research advances

    Institute of Scientific and Technical Information of China (English)

    张启燕; 张文会; 肖军海; 李松

    2016-01-01

    Picornaviruses(PV)and coronaviruses(CoV) are positive-stranded RNA viruses. Pathogens in the family can cause hand,foot and mouth disease,myocarditis, common cold ,severe respiratory and intestinal diseases. 3C and 3CL proteases, belonging to cysteine proteases,are required to process polyproteins into mature proteins for viral replication,which plays an impor⁃tant role in viral replication because substrate binding sites are highly conservative and have similar catalytic mechanism. 3C and 3CL proteases are different from protease in the human body ,which represents a promising anti-viral drug target. Using 3C and 3CL pro⁃teinase structural similarities,broad spectrum protease inhibitors have been found successfully. This review describes recent develop⁃ments of broad spectrum protease inhibitors targeting on 3C and 3CL proteases,and briefly illustrates the mechanism of the inhibitors, which may benefit to the development of virus therapy.%小RNA病毒和冠状病毒属于单正链RNA病毒,其家族中的病原体易导致手足口病、心肌炎、普通感冒以及严重的呼吸道和肠道疾病。3C和3CL蛋白酶都属于半胱氨酸蛋白酶,底物结合位点高度保守且具有相似的催化机制,是催化单正链RNA病毒前体蛋白裂解的关键蛋白酶,对病毒的复制有重要作用。人体中没有与其相似的蛋白酶,是目前广谱抗单正链RNA病毒研究的重要靶点。利用3C和3CL蛋白酶结构的相同点,成功发现了具有广谱作用的蛋白酶抑制剂。本文简要概述3C和3CL蛋白酶的结构、功能和广谱抑制剂的研究进展,并简要阐释抑制剂的作用机制,对该类酶的广谱抑制剂研究和相关病毒的治疗具有指导意义。

  20. Two-step crystal engineering of porous nets from [Cr3(μ 3-O)(RCO2)6] and [Cu3(μ 3-Cl)(RNH2)6Cl6] molecular building blocks

    KAUST Repository

    Elsaidi, Sameh K.

    2013-01-01

    Two porous nets have been prepared via a 2-step crystal engineering approach that links decorated trigonal prismatic [Cr3(μ 3-O)(CO2)6] and [Cu3(μ 3-Cl)(RNH2)6Cl6] molecular building blocks, MBBs. tp-PMBB-5-acs-1 is a rare example of a rigid acs underlying net whereas tp-PMBB-6-stp-1, an stp underlying net, exhibits free NH2 groups in its channels and a relatively high isosteric heat of adsorption for CO2. © 2013 The Royal Society of Chemistry.

  1. Vapor-Liquid Equilibrium in the Mixture 1,1,1-Trichloroethane C2H3Cl3 + C6H10O Cyclohexanone (EVLM1111, LB5638_E)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'vapor-Liquid Equilibrium in the Mixture 1,1,1-Trichloroethane C2H3Cl3 + C6H10O Cyclohexanone (EVLM1111, LB5638_E)' providing data from direct measurement of pressure at variable mole fraction in liquid phase and constant temperature.

  2. Enhanced photoelectrochemical cathodic protection performance of the C{sub 3}N{sub 4}@In{sub 2}O{sub 3} nanocomposite with quasi-shell–core structure under visible light

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Mengmeng; Chen, Zhuoyuan, E-mail: zychen@qdio.ac.cn; Bu, Yuyu

    2015-01-05

    Highlights: • The C{sub 3}N{sub 4}@In{sub 2}O{sub 3} composite with quasi-shell–core structure is prepared. • Photoelectrochemical cathodic protection performance of this composite was studied. • C{sub 3}N{sub 4} coating on In{sub 2}O{sub 3} dramatically enhances its light absorption capability. • C{sub 3}N{sub 4} coating on In{sub 2}O{sub 3} dramatically enhances its photoelectrochemical properties. • C{sub 3}N{sub 4} coating on In{sub 2}O{sub 3} dramatically enhances its electron transfer capability. - Abstract: Carbon nitride@Indium oxide (C{sub 3}N{sub 4}@In{sub 2}O{sub 3}) composite with quasi-shell–core structure was successfully prepared in this work. The photoinduced open circuit potential and current density results show that the C{sub 3}N{sub 4}@In{sub 2}O{sub 3} composite with quasi-shell–core structure could provide the optimal photoelectrochemical cathodic protection capability for 304 stainless steel under visible light when the adding amount of C{sub 3}N{sub 4} in the C{sub 3}N{sub 4}@In{sub 2}O{sub 3} composite is 3 wt%. The light absorption capability of the C{sub 3}N{sub 4}@In{sub 2}O{sub 3} composite was enhanced due to the synergistic effect of heterojunction structure. According to the HRTEM images, photoinduced Volt–Ampere characteristic curves and electrochemical impedance spectra, the ultrathin coating layer of C{sub 3}N{sub 4} on the surface of In{sub 2}O{sub 3} helps to form a heterojunction electric field at the interface between C{sub 3}N{sub 4} and In{sub 2}O{sub 3}, which enhances the separation efficiency of the photogenerated electron–hole pairs. Excessive C{sub 3}N{sub 4} will decline the photoelectrochemical cathodic protection of this composite due to the lower intrinsic electronic mobility and the lower photoelectric conversion property of C{sub 3}N{sub 4}.

  3. Effects of carbon nanomaterials fullerene C{sub 60} and fullerol C{sub 60}(OH){sub 18-22} on gills of fish Cyprinus carpio (Cyprinidae) exposed to ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Socoowski Britto, Roberta; Longaray Garcia, Marcia; Martins da Rocha, Alessandra [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil); Artigas Flores, Juliana [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Pinheiro, Mauricio V. Brant [Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, MG (Brazil); Monserrat, Jose Maria [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil); Ribas Ferreira, Josencler L., E-mail: josenclerf@gmail.com [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil)

    2012-06-15

    In consequence of their growing use and demand, the inevitable environmental presence of nanomaterials (NMs) has raised concerns about their potential deleterious effects to aquatic environments. The carbon NM fullerene (C{sub 60}), which forms colloidal aggregates in water, and its water-soluble derivative fullerol (C{sub 60}(OH){sub 18-22}), which possesses antioxidant properties, are known to be photo-excited by ultraviolet (UV) or visible light. To investigate their potential hazards to aquatic organisms upon exposure to UV sunlight, this study analyzed (a) the in vitro behavior of fullerene and fullerol against peroxyl radicals (ROO{center_dot}) under UV-A radiation and (b) the effects of these photo-excited NMs on oxidative stress parameters in functional gills extracted from the fish Cyprinus carpio (Cyprinidae). The variables measured were the total antioxidant capacity, lipid peroxidation (TBARS), the activities of the antioxidant enzymes glutathione reductase (GR) and glutamate cysteine ligase (GCL), and the levels of the non-enzymatic antioxidant glutathione (GSH). The obtained results revealed the following: (1) both NMs behaved in vitro as antioxidants against ROO{center_dot} in the dark and as pro-oxidants in presence of UV-A, the latter effect being reversed by the addition of sodium azide, which is a singlet oxygen ({sup 1}O{sub 2}) quencher; (2) fullerene induced toxicity with or without UV-A incidence, with a significant (p < 0.05) increase in lipid peroxidation (with greater damage under illumination), a decrease in GCL activity, and the depletion of GSH stocks (under illumination), all of which were attributed to {sup 1}O{sub 2} generation; and (3) fullerol also decreased GCL activity and GSH formation (p < 0.05) but without lipid damage. The overall results show that fullerene can be toxic with or without light incidence, whereas UV radiation seems to play a key role in the environmental toxicity of carbon NMs through {sup 1}O{sub 2} formation.

  4. Comparative study of the catalytic activity of the complexes Cp{sup *}RuCl(PAr{sub 3}){sub 2} [Ar = -C{sub 6H}5 and 4-CF{sub 3}-C{sub 6}H{sub 4}] in the ATRP of styrene

    Energy Technology Data Exchange (ETDEWEB)

    Villa-Hernandez, Alejandro M.; Rosales-Velazquez, Claudia P.; Torres-Lubian, Jose R., E-mail: rtorres@ciqa.mx [Departamento de Sintesis de Polimeros, Centro de Investigacion en Quimica Aplicada, Coah. (Mexico); Saldivar-Guerra, Enrique [Departamento de Procesos de Polimerizacion, Centro de Investigacion en Quimica Aplicada, Coah. (Mexico)

    2011-09-15

    Styrene polymerization by ATRP was conducted independently using the complexes Cp{sup *}RuCl(PPh{sub 3}){sub 2}, and Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} as catalysts, in order to evaluate the influence of the electronic properties of the phosphine ligands on the rate and control of the polymerization. The kinetic data for polymerizations carried out with Cp{sup *}RuCl(PPh{sub 3}){sub 2}, show that molecular weights increase linearly with conversion with an average initiation efficiency of 0.77. The molecular weights obtained in the kinetic study with Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} also increase with conversion but show a marked deviation below the theoretical molecular weights. This behavior was explained by the gradual, irreversible, oxidation of catalyst Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} as confirmed by {sup 31}P-NMR spectroscopy. Catalyst Cp{sup *}RuCl(PPh{sub 3}){sub 2} promotes the polymerization with a rate of polymerization higher than that obtained using Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2}; this is consistent with the better electron donating properties of PPh{sub 3} versus P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}. Preliminary studies of styrene polymerization by ATRP in supercritical CO{sub 2}, shows that only catalyst Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2}, with fluorinated ligands, was active. (author)

  5. A 3d-4f complex constructed by the assembly of a cationic template, [Cu(en){sub 2}]{sup 2+}, and a 3D anionic coordination polymer, [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}(C{sub 5}O{sub 5})(H{sub 2}O){sub 2}]{sup 2-}

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Szu-Yu; Yeh, Chang-Tsung; Wang, Chih-Chieh [Department of Chemistry, Soochow University, Taipei, Taiwan (China); Lee, Gene-Hsiang [Instrumentation Center, National Taiwan University, Taipei, Taiwan (China); Sheu, Hwo-Shuenn [National Synchrotron Radiation Research Center, Hsinchu, Taiwan (China)

    2017-05-18

    A three-dimensional (3D) 3d-4f complex, [Cu(en){sub 2}][Sm{sub 2}(C{sub 5}O{sub 5})(C{sub 2}O{sub 4}){sub 3}(H{sub 2}O){sub 2}].8H{sub 2}O (1) (en = ethylenediamine, C{sub 5}O{sub 5}{sup 2-} = dianion of 4,5-dihydroxycyclopent-4-ene-1,2,3-trione), were prepared via the in-situ ring-opening oxidation reaction of croconate in the presence of the template-directed complex, [Cu(en){sub 2}]{sup 2+} cation. The structural characterization determined by X-ray diffraction determination reveals that the 3D anionic coordination polymer of [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}(C{sub 5}O{sub 5})(H{sub 2}O){sub 2}]{sup 2-} in 1 can be describe in terms of in-plane 2D honeycomb-like [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}] layered frameworks bridged by oxalate with bis-chelating mode, being mutually interlinked via the bridge of μ{sub 1,2,3,4}-croconate ligands with bis-chelating coordination mode to complete the 3D open framework, which gives rise to 1D channels with pore size of 14.023 x 11.893 Aa (longest atom-atom contact distances) along the b axis. The structure-directing complex, [Cu(en){sub 2}]{sup 2+}, and solvated water molecules are resided into these honeycomb-type hexagonal channels. The thermal stability of 1 was further studied by TGA and in-situ powder X-ray diffraction measurement. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Effect of ageing temperature after tensile pre deformation on shape memory effect and precipitation process of Cr{sub 23}C{sub 6} carbide in a FeMnSiCrNiC alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S.Z. [College of Manufacturing Science and Engineering, Sichuan University, 24, South Section 1, Yihuan Road, Chengdu 610065, Sichuan (China); College of Material Science and Engineering, Xihua University, Chengdu 610039 (China); Li, N., E-mail: yangshizhou@163.com [College of Manufacturing Science and Engineering, Sichuan University, 24, South Section 1, Yihuan Road, Chengdu 610065, Sichuan (China); Wen, Y.H.; Peng, H.B. [College of Manufacturing Science and Engineering, Sichuan University, 24, South Section 1, Yihuan Road, Chengdu 610065, Sichuan (China)

    2011-11-25

    Highlights: {yields} Precipitation process of Cr{sub 23}C{sub 6} particles depends on diffusion capacity of Cr atom. {yields} Directional segregation of carbon atom can act as aligned Cr{sub 23}C{sub 6} in improving SME. {yields} Ageing temperature and ageing time greatly affect precipitation process of Cr{sub 23}C{sub 6}. {yields} NbC carbides in a FeMnSiCrNiNbC alloy are prone to dispersively precipitate. - Abstract: Researches showed that the shape memory effect (SME) of FeMnSiCrNiC alloys can be remarkably improved through aligned Cr{sub 23}C{sub 6} particles or carbon atom segregation inside grains. To further study on influencing factors in improving SME and aligned precipitation process of Cr{sub 23}C{sub 6} carbide in a FeMnSiCrNiC alloy, effect of ageing temperature after tensile pre deformation on shape memory effect and precipitation process of Cr{sub 23}C{sub 6} carbide in a FeMnSiCrNiC alloy was studied. The results showed that aligned precipitation of Cr{sub 23}C{sub 6} carbide in a FeMnSiCrNiC alloy mainly depends on diffusion capacity and directional segregation of carbon and chromium atoms, namely on ageing temperature, ageing time and the amount of tensile pre deformation.

  7. THE ABUNDANCE OF C{sub 3}H{sub 2} AND OTHER SMALL HYDROCARBONS IN THE DIFFUSE INTERSTELLAR MEDIUM

    Energy Technology Data Exchange (ETDEWEB)

    Liszt, Harvey [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Sonnentrucker, Paule [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Cordiner, Martin [Astrochemistry Laboratory and the Goddard Center for Astrobiology, Mailstop 691, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20770 (United States); Gerin, Maryvonne, E-mail: hliszt@nrao.edu [LERMA, UMR 8112 du CNRS, Observatoire de Paris Ecole Normale Superieure, UPMC and UCP (France)

    2012-07-10

    Hydrocarbons are ubiquitous in the interstellar medium, observed in diverse environments ranging from diffuse to molecular dark clouds and strong photon-dominated regions near H II regions. Recently, two broad diffuse interstellar bands (DIBs) at 4881 A and 5450 A were attributed to the linear version of propynylidene l-C{sub 3}H{sub 2}, a species whose more stable cyclic conformer c-C{sub 3}H{sub 2} has been widely observed in the diffuse interstellar medium at radio wavelengths. This attribution has already been criticized on the basis of indirect plausibility arguments because the required column densities are quite large, N(l-C{sub 3}H{sub 2})/E{sub B-V} =4 Multiplication-Sign 10{sup 14} cm{sup -2} mag{sup -1}. Here we present new measurements of N(l-C{sub 3}H{sub 2}) based on simultaneous 18-21 GHz Very Large Array absorption profiles of cyclic and linear C{sub 3}H{sub 2} taken along sight lines toward extragalactic radio-continuum background sources with foreground Galactic reddening E{sub B-V} = 0.1-1.6 mag. We find that N(l-C{sub 3}H{sub 2})/N(c-C{sub 3}H{sub 2}) Almost-Equal-To 1/15-1/40 and N(l-C{sub 3}H{sub 2})/E{sub B-V} Almost-Equal-To (2 {+-} 1) Multiplication-Sign 10{sup 11} cm{sup -2} mag{sup -1}, so that the column densities of l-C{sub 3}H{sub 2} needed to explain the DIBs are some three orders of magnitude higher than what is observed. We also find N(C{sub 4}H)/E{sub B-V} <1.3 Multiplication-Sign 10{sup 13} cm{sup -2} mag{sup -1} and N(C{sub 4}H{sup -})/E{sub B-V} <1 Multiplication-Sign 10{sup 11} cm{sup -2} mag{sup -1} (3{sigma}). Using available data for CH and C{sub 2}H we compare the abundances of small hydrocarbons in diffuse and dark clouds as a guide to their ability to contribute as DIB carriers over a wide range of conditions in the interstellar medium.

  8. A new imidazolium-embedded C{sub 18} stationary phase with enhanced performance in reversed-phase liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Hongdeng [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Mallik, Abul K. [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Takafuji, Makoto [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901 (Japan); Liu Xia; Jiang Shengxiang [Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Ihara, Hirotaka, E-mail: ihara@kumamoto-u.ac.jp [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901 (Japan)

    2012-08-13

    Highlights: Black-Right-Pointing-Pointer Imidazolium-embedded C{sub 18} stationary phase was prepared and characterized. Black-Right-Pointing-Pointer Enhanced chromatographic selectivity was observed in SiImC{sub 18} column. Black-Right-Pointing-Pointer Seven nucleosides and bases were separated using only water as eluent within 8 min. Black-Right-Pointing-Pointer Multiple-interactions induced by embedded polar imidazolium was investigated. - Abstract: In this paper, a new imidazolium-embedded C{sub 18} stationary phase (SiImC{sub 18}) for reversed-phase high-performance liquid chromatography is described. 1-Allyl-3-octadecylimidazolium bromide ionic liquid compound having a long alkyl chain and reactive groups was newly prepared and grafted onto 3-mercaptopropyltrimethoxysilane-modified silica via a surface-initiated radical-chain transfer addition reaction. The SiImC{sub 18} obtained was characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, diffuse reflectance infrared Fourier transform, and solid-state {sup 13}C and {sup 29}Si cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy. The selectivity toward polycyclic aromatic hydrocarbons relative to that toward alkylbenzenes exhibited by SiImC{sub 18} was higher than the corresponding selectivity exhibited by a conventional octadecyl silica (ODS) column, which could be explained by electrostatic {pi}-{pi} interaction cationic imidazolium and electron-rich aromatic rings. On the other hand, SiImC{sub 18} also showed high selectivity for polar compounds, which was based on the multiple interaction and retention mechanisms of this phase with different analytes. 1,6-Dinitropyrene and 1,8-dinitropyrene, which form a positional isomer pair of dipolar compounds, were separated successfully with the SiImC{sub 18} phase. Seven nucleosides and bases (i.e. cytidine, uracil, uridine, thymine, guanosine, xanthosine, and adenosine) were separated using only water as

  9. Free radical hydrogen atom abstraction from saturated hydrocarbons: A crossed-molecular-beams study of the reaction Cl + C{sub 3}H{sub 8} {yields} HCl + C{sub 3}H{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Blank, D.A.; Hemmi, N.; Suits, A.G.; Lee, Y.T. [Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    The abstraction of hydrogen atoms from saturated hydrocarbons are reactions of fundamental importance in combustion as well as often being the rate limiting step in free radical substitution reactions. The authors have begun studying these reactions under single collision conditions using the crossed molecular beam technique on beamline 9.0.2.1, utilizing VUV undulator radiation to selectively ionize the scattered hydrocarbon free radical products (C{sub x}H{sub 2x+1}). The crossed molecular beam technique involves two reactant molecular beams fixed at 90{degrees}. The molecular beam sources are rotatable in the plane defined by the two beams. The scattered neutral products travel 12.0 cm where they are photoionized using the VUV undulator radiation, mass selected, and counted as a function of time. In the authors initial investigations they are using halogen atoms as protypical free radicals to abstract hydrogen atoms from small alkanes. Their first study has been looking at the reaction of Cl + propane {r_arrow} HCl + propyl radical. In their preliminary efforts the authors have measured the laboratory scattering angular distribution and time of flight spectra for the propyl radical products at collision energies of 9.6 kcal/mol and 14.9 kcal/mol.

  10. Multiparticle excitations in the {sup 149} Gd superdeformed nucleus. Signature of new C{sub 4} nucleus symmetry; Excitations multiparticules dans le noyau superdeforme {sup 149}Gd. Signature d`une symetrie nouvelle C{sub 4} du noyau

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, C.

    1995-01-01

    The use of 8 {pi} and EUROGAM phase I multi-detectors for the study of high spin states of {sup 149} Gd nucleus has revealed unexpected new phenomenons about the superdeformation in this nucleus. The new excited bands confirm the omnipresence of twin bands phenomenon. A new multi-particle excitation (two protons and one neutron) has been discovered. Thanks to the second generation EUROGAM detector, unexpected discoveries such as C{sub 4} symmetry, level interactions, complete backbending were obtained for the second potential well. The knowledge of interacting levels gives informations about the nucleon-nucleon residual interaction and could allow the determination of SD bands excitation energy. The complex processing and analysis of high multiplicity events has led to the development of new computing tools. An automatic band research program has been written for the discovery of new excited bands, and an exact method for the elimination of uncorrected events has been developed. The improvements of multi-detector performances should allow the discovery of more exceptional phenomenons and new anomalies in the SD bands. (J.S.). 222 refs., 86 figs., 38 tabs.

  11. Ion-Exchange-Induced 2D-3D Conversion of HMA1-x FAx PbI3 Cl Perovskite into a High-Quality MA1-x FAx PbI3 Perovskite.

    Science.gov (United States)

    Li, Ge; Zhang, Taiyang; Guo, Nanjie; Xu, Feng; Qian, Xufang; Zhao, Yixin

    2016-10-17

    High-quality phase-pure MA1-x FAx PbI3 planar films (MA=methylammonium, FA=formamidinium) with extended absorption and enhanced thermal stability are difficult to deposit by regular simple solution chemistry approaches owing to crystallization competition between the easy-to-crystallize but unwanted δ-FAPbI3 /MAPbI3 and FAx MA1-x PbI3 requiring rigid crystallization conditions. Here A 2D-3D conversion to transform compact 2D mixed composition HMA1-x FAx PbI3 Cl perovskite precursor films into 3D MA1-x FAx PbI3 (x=0.1-0.9) perovskites is presented. The designed Cl/I and H/FA(MA) ion exchange reaction induced fast transformation of compact 2D perovskite film, helping to form the phase-pure and high quality MA1-x FAx PbI3 without δ-FAPbI3 and MAPbI3 impurity. In all, we successfully developed a facile one-step method to fabricate high quality phase-pure MA1-x FAx PbI3 (x=0.1-0.9) perovskite films by 2D-3D conversion of HMA1-x FAx PbI3 Cl perovskite. This 2D-3D conversion is a promising strategy for lead halide perovskite fabrication.

  12. Photochromic hybrid containing in situ-generated benzyl viologen and novel trinuclear [Bi3Cl14]5-: improved photoresponsive behavior by the π···π interactions and size effect of inorganic oligomer.

    Science.gov (United States)

    Lin, Rong-Guang; Xu, Gang; Lu, Gang; Wang, Ming-Sheng; Li, Pei-Xin; Guo, Guo-Cong

    2014-06-02

    Two new member of (V)((2n+2)/2)[Bi(2n)Cl(8n+2)] series hybrids, (BzV)2[Bi2Cl10] (1) and (BzV)5[Bi3Cl14]2·(C6H5CH2)2O (2) (where BzV(2+) = N,N'-dibenzyl-4,4'-bipyridinium and (C6H5CH2)2O = dibenzyl ether) have been obtained, and compound 2 contains an unprecedented discrete trimer [Bi3Cl14](5-) counterion. The novel in situ-synthesized symmetric viologen cation with aromatic groups on both sides of 4,4'-bipy would provide more opportunities to create π···π interactions to optimize the photochromic property of the hybrid, and different bismuthated-halide oligomers enable us to discuss the size effect in this series of compounds. Both 1 and 2 are photochromic, and their photoresponsive rate is faster than that of reported viologen-metal halide hybrids. Experimental and theoretical data illustrated that the size of the inorganic oligomer can significantly influence the photoresponsive rate of the viologen dication, and the π···π interaction behaves as not only a powerful factor to stabilize the viologen monocation radical but also the second electron-transfer pathway, from a π-conjugated substituent to a viologen cation, for the photochromic process.

  13. C{sub 2}{sup +} selectivity enhancement in oxidative coupling of methane over microwave-irradiated catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Roussy, G.; Marchal, E.; Thiebaut, J.M.; Kiennemann, A.; Maire, G. [L.S.T.M. Universite Henri Poincare Nancy, Vandoeuvre-les-Nancy (France)

    1997-02-01

    The oxidative coupling of methane over Li/MgO and BaBiO{sub 3-x} catalysts irradiated by microwaves and classically heated is reported. Enhanced selectivities in C{sub 2}{sup +} products are observed at lower temperatures under microwave conditions, especially with the Li/MgO catalyst. The complex permittivity measurements of BaBiO{sub 3-x} show that the regeneration of the active oxygen species on the surface is lower under microwave irradiation than classical heating. X-ray diffraction analyses of the catalyst before and after catalytic reaction, when it is classically heated and when it is heated by microwave irradiation, corroborate these results. Therefore, the CH{sub 3}{sup -} carbanions are less oxidated at the catalyst surface under microwave irradiation. On the other hand, the quenching of the output gas probably decreases the oxidation of CH{sub 3}{sup 0} radicals in the gas phase when the Li/MgO catalyst is irradiated by microwaves. The quenching of the output gas is a unique consequence of microwave irradiation which heats the catalyst without heating the wall of the reactor. 26 refs., 9 figs.

  14. Formation of ion tracks in amorphous silicon nitride films with MeV C{sub 60} ions

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, T.; Morita, Y.; Nakajima, K. [Department of Micro Engineering, Kyoto University, Kyoto 606-8501 (Japan); Narumi, K.; Saitoh, Y. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Matsuda, M.; Sataka, M. [Nuclear Science Research Institute, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Tsujimoto, M.; Isoda, S. [Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501 (Japan); Toulemonde, M. [CIMAP-GANIL (CEA-CNRS-ENSICAEN-Université de Caen Basse Normandie), Bd. H. Becquerel, 14070 Caen (France); Kimura, K., E-mail: kimura@kues.kyoto-u.ac.jp [Department of Micro Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2015-08-01

    Amorphous silicon nitride (a-SiN) films (thickness 5–100 nm) were irradiated with 0.12–5 MeV C{sub 60}, 100 MeV Xe, 200 MeV Kr, and 200 and 420 MeV Au ions. Ion tracks were clearly observed using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) except for 100 MeV Xe and 200 MeV Kr. The observed HAADF-STEM images showed that the ion tracks consist of a low density core (0.5–2 nm in radius) and a high density shell (several nm in radius). The observed core and shell radii are not simply correlated with the electronic energy loss indicating that the nuclear energy loss plays an important role in the both core and shell formations. The observed track radii were well reproduced by the unified thermal spike model with two thresholds for shell and core formations.

  15. Molecular dynamics study of polystyrene bond-breaking and crosslinking under C{sub 60} and Ar{sub n} cluster bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Czerwinski, Bartlomiej, E-mail: bartlomiej.czerwinski@uclouvain.be [Institute of Condensed Matter and Nanosciences – Bio and Soft Matter (IMCN/BSMA), Université Catholique de Louvain, 1 Croix du Sud, B-1348 Louvain-la-Neuve (Belgium); Postawa, Zbigniew [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow (Poland); Garrison, Barbara J. [Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (United States); Delcorte, Arnaud [Institute of Condensed Matter and Nanosciences – Bio and Soft Matter (IMCN/BSMA), Université Catholique de Louvain, 1 Croix du Sud, B-1348 Louvain-la-Neuve (Belgium)

    2013-05-15

    Molecular dynamics computer simulations are used to elucidate the bond-breaking and crosslinking processes induced by 2.5 keV C{sub 60} and Ar{sub n} cluster bombardment in an amorphous sec-butyl-terminated polystyrene sample. The obtained results indicate that replacement of C{sub 60} by Ar{sub 18} or Ar{sub 60} projectiles leads to the decrease of the number of broken bonds and, hence, to the decrease of formation of new intra- and intermolecular (crosslinking) bonds. When the number of atoms in the Ar{sub n} cluster is increased from 60 to 250 or more, the total number of broken bonds and the total number of newly created bonds reach a zero value. Additional comparison to the case of a fullerite crystal reveals that the change of material properties leads to almost 7.5-fold reduction of the efficiency of the crosslinking process.

  16. PENTACARBON DIOXIDE (C{sub 5}O{sub 2}) FORMATION AND ITS ROLE AS A TRACER OF SOLAR SYSTEM EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Förstel, Marko; Maksyutenko, Pavlo; Kaiser, Ralf I. [W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, HI 96822 (United States); Mebel, Alexander M., E-mail: ralfk@hawaii.edu [Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33193 (United States)

    2016-02-20

    Carbon monoxide is the second most abundant molecule on icy grains in the interstellar medium. These grains are under the influence of ionizing radiation, which induces the chemical reaction within the ice. Here we report the first observation of subliming pentacarbon dioxide (C{sub 5}O{sub 2}) after irradiation of pure carbon monoxide ice with energetic electrons. Our results show that pentacarbon dioxide is a stable reaction product in a carbon monoxide matrix that survives the sublimation in star-forming regions at sublimation temperatures of 175 K. Along with carbon suboxide (C{sub 3}O{sub 2}), this molecule can serve as a powerful tracer of the temperature history of formerly carbon monoxide rich ices in molecular clouds and star-forming regions.

  17. Crystal structure of a new amine nitrate: 4-dimethylaminopyridinium nitrate (C{sub 7}H{sub 11}N{sub 2})NO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Benhassan, D., E-mail: houcine-naili@yahoo.com; Rekik, W.; Naïli, H. [Université de Sfax, Laboratoire Physicochimie de l’Etat Solide, Département de Chimie Faculté des Sciences de Sfax (Tunisia); Ślepokura, Katarzyna [University of Wroclaw, Faculty of Chemistry (Poland)

    2015-12-15

    The title compound (C{sub 7}H{sub 11}N{sub 2})NO{sub 3} (I) was obtained by the slow evaporation method at room temperature. Its crystal structure consists of organic cations (C{sub 7}H{sub 11}N{sub 2}){sup +} and nitrate anions (NO{sub 3}){sup –} linked by two types of hydrogen bonds. Each monoprotonated nitrogen atom, called bifurcated, is engaged in two N–H···O hydrogen bonds with two symmetric oxygen atoms. In addition, the crystal structure stability is established by C–H···O hydrogen bonds that ensure the formation of infinite layers, parallel to (001) plane. These layers are related together through π···π interactions established between aromatic amines.

  18. A photoelectron spectroscopic investigation of vinyl fluoride (C{sub 2}H{sub 3}F): the HeI, threshold and CIS photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Locht, R; Leyh, B [Laboratoire de Dynamique Moleculaire, Departement de Chimie, Institut de Chimie, Bat.B6c, Universite de Liege, Sart-Tilman par B-4000 Liege 1 (Belgium); Dehareng, D [Centre d' Ingenierie des Proteines, Institut de Chimie, Bat.B6a, Universite de Liege, Sart-Tilman par B-4000 Liege 1 (Belgium); Hottmann, K; Baumgaertel, H, E-mail: robert.locht@ulg.ac.b [Institut fuer Physikalische und Theoretische Chemie, Freie Universitaet Berlin, Takustrasse 3, D-14195 Berlin (Germany)

    2010-01-14

    The threshold photoelectron spectrum (TPES) and the constant ion state (CIS) spectra of the individual ionic states of C{sub 2}H{sub 3}F have been recorded using synchrotron radiation. For comparison a well-resolved HeI photoelectron spectrum (HeI-PES) has also been measured and analysed in detail. The TPES has been measured between 9.5 eV and 35 eV photon energy. Numerous vibrational structures, reported for the first time, observed in the ground state and the six excited states of the cation are analysed. Quantum chemical calculations have been performed and provide strong support to the assignments. State-selected CIS spectra highlighted the major importance of autoionization for the production of almost all ionized states of C{sub 2}H{sub 3}F observed in this work.

  19. Study of morphology of aerosol aggregates formed during co-pyrolysis of C{sub 3}H{sub 8} + Fe(CO){sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, N A [Institute of Chemical Kinetics and Combustion SB RAS, 630090, Novosibirsk (Russian Federation); Onischuk, A A [Institute of Chemical Kinetics and Combustion SB RAS, 630090, Novosibirsk (Russian Federation); Di Stasio, S [Istituto Motori CNR Aerosol and Nanostructures Laboratory, Via Marconi 8, 80125 Naples (Italy); Baklanov, A M [Institute of Chemical Kinetics and Combustion SB RAS, 630090, Novosibirsk (Russian Federation); Makhov, G A [Institute of Chemical Kinetics and Combustion SB RAS, 630090, Novosibirsk (Russian Federation)

    2007-04-07

    Formation of aerosol nanoparticles as well as carbon nanotubes and nanofilaments is studied during co-pyrolysis of iron pentacarbonyl and propane with argon as a carrier gas in a flow reactor. Gaseous intermediates from propane thermal decomposition (CH{sub 4}, C{sub 2}H{sub 6} and C{sub 3}H{sub 4}) and Fe(CO){sub 5} conversion are monitored by gas chromatography and IR-spectroscopy, respectively. The aerosol morphology is studied by transmission electron microscopy (TEM) and high resolution TEM. The aerosol particle concentration and size distribution are measured by an automated diffusion battery. The crystal phase composition of particles is studied by x-ray diffractometry. The decomposition of the Fe(CO){sub 5} + Ar mixture resulted in an iron aggregate formation composed of fine primary particles. In the case of lower pyrolysis temperatures, about 450 K, the primary particle mean diameter is about 10 nm, and consequently, the majority of the primary particles are superparamagnetic, thus forming compact aggregates. At intermediate pyrolysis temperatures in the range 800-1040 K the primary particle diameter is about 20-30 nm, and most of the particles are ferromagnetic in nature. The coagulation of these particles results in a chain-like aggregate formation. Finally, at temperatures higher than the Curie point (1043 K) the ferromagnetic properties vanish and the formation of compact aggregates is observed again. The co-pyrolysis of Fe(CO){sub 5} and C{sub 3}H{sub 8} mixed with Ar carrier gas resulted in aerosol aggregate structures dramatically different from those formed by iron pentacarbonyl pyrolysis. In particular, in the temperature range 1070-1280 K, we observed Fe{sub 3}C particles connected by long carbon nanotubes (CNTs). The aggregate morphology is described in terms of a fractal-like dimension D{sub f}, which is determined from TEM images on the basis of a scaling power law linking the aggregate mass (M) and radius (R), M{approx}R{sup D{sub f}}. The

  20. Single-operator multiparameter metabolic analyzer (SOMMA) for total carbon dioxide (C{sub T}) with coulometric detection. Operator`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K.M.

    1992-01-01

    This manual contains the presently known information about using the SOMMA (Single-Operator Multiparameter Metabolic Analyzer) -Coulometer system for total carbon dioxide (C{sub T}) analysis of seawater samples. Being Version 1.0, it is preliminary and will be revised as new information is obtained from SOMMA users. As part of a US Department of Energy (DOE) program to conduct a global survey of CO{sub 2} in the ocean in conjunction with the World Ocean Circulation Experiment (WOCE) Hydrographic Program and Joint Global Ocean Flux Study, C{sub T} measurements are being made with SOMMA systems by several US and foreign laboratories. The purpose of the manual and future versions is to improve the accuracy and precision of seawater analysis through better documentation of methods and to facilitate communication of new operating procedures.

  1. Incorporation in Langmuir-Blodgett films of an amphiphilic derivative of fullerene C{sub 60} and oligo-para-phenylenevinylene

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Venicio, V. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, CU, C.P. 04510, D.F. (Mexico); Gutierrez-Nava, M. [CIATEQ, A.C., Centro de Tecnologia Avanzada, Circuito de la Industria Poniente Lote: 11, Mza. 3, No. 11, Colonia Parque Industrial Ex Hacienda Dona Rosa, Lerma C.P. 52004, Estado de Mexico (Mexico); Amelines-Sarria, O. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, CU, C.P. 04510, D.F. (Mexico); Alvarez-Zauco, E. [Facultad de Ciencias, UNAM, Circuito Exterior, C.U., C.P. 04510, D.F. (Mexico); Basiuk, V.A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, CU, C.P. 04510, D.F. (Mexico); Carreon-Castro, M.P., E-mail: pilar@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, CU, C.P. 04510, D.F. (Mexico)

    2012-12-30

    Langmuir (L) and Langmuir-Blodgett (LB) films of fullerene C{sub 60}-oligo-para-phenylenevinylene (OPV) derivative with six C{sub 12}H{sub 25} aliphatic chains were characterized. For the Langmuir films, isotherms of surface pressure versus molecular area, compression/expansion cycles (hysteresis curves) and Brewster angle microscopic images were obtained. We performed molecular mechanics and density functional theory calculations to determine the molecular and electronic structure of our compound at a water-air interface. We found agreement between experimental and theoretical values for the molecular surface area. LB films of up to ten layers were obtained on glass substrates, and were characterized by ultraviolet-visible spectroscopy. We observed that the absorbance at a wavelength of 326 nm grows almost linearly as a function of the number of layers. Films on glass-indium tin oxide were characterized by atomic force microscopy. We also observed a uniform deposition over the whole area of the scanned substrate. We demonstrated that the fullerene C{sub 60}-OPV derivative is able to form both L and LB films preventing fullerene aggregation with its aliphatic chains. We suggest that, due to its electron-acceptor properties, the C{sub 60}-OPV derivative could be used for organic-photovoltaic and organic-electronic applications. - Highlights: Black-Right-Pointing-Pointer We performed isotherm and hysteresis studies of fullerene derivative compound. Black-Right-Pointing-Pointer We found that the theoretical and experimental molecular areas agree. Black-Right-Pointing-Pointer We deposited Langmuir-Blodgett (LB) films on glass-indium tin oxide. Black-Right-Pointing-Pointer LB films were characterized using UV-visible spectroscopy. Black-Right-Pointing-Pointer We observed the morphology of the LB films through atomic force microscopy.

  2. Molecular beam studies of unimolecular reactions: Cl, F + C/sub 2/H/sub 3/Br. [Angular and velocity distributions, mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Buss, R.J.; Coggiola, M.J.; Lee, Y.T.

    1978-12-01

    Several methods currently used to study unimolecular decomposition in molecular beams are discussed. Experimental product angular and velocity distributions obtained for the reaction of F, Cl with C/sub 2/H/sub 3/Br are presented. The mechanism by which conservation of angular momemtum can cause coupling of the product angular and velocity distributions in dissociation of long-lived complexes is introduced. 14 references.

  3. Use of Al{sub 4}C{sub 3} for fabrication of alumina–niobium carbide composites by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, C.L., E-mail: clyeh@fcu.edu.tw; Chen, Y.S.

    2014-03-15

    Highlights: • SHS with aluminothermic reduction was performed for formation of NbC and Nb{sub 2}C–Al{sub 2}O{sub 3} composites. • Al{sub 4}C{sub 3} prevents carbothermic reduction of Nb{sub 2}O{sub 5}, leading to improved product formation. • Optimum sample compositions were obtained for formation of NbC and Nb{sub 2}C–Al{sub 2}O{sub 3} composites. • Variations of combustion temperature and velocity with sample stoichiometry were presented. -- Abstract: Alumina–niobium carbide (Al{sub 2}O{sub 3}–NbC and Al{sub 2}O{sub 3}–Nb{sub 2}C) composites were synthesized by incorporating aluminothermic reduction of Nb{sub 2}O{sub 5} into a self-propagating combustion process. Starting materials of this study included Nb{sub 2}O{sub 5}, Al, Al{sub 4}C{sub 3} and carbon powders. Experimental evidence indicated that combustion temperature and flame-front velocity decreased with increasing elemental carbon in the reactant mixture. The use of Al{sub 4}C{sub 3} as the source of carbon was demonstrated to prevent carbothermic reduction of Nb{sub 2}O{sub 5}. As a result, the combustion exothermicity was increased and phase transformation and product densification were improved. According to the composition analysis, the carbon-free samples composed of Nb{sub 2}O{sub 5}:Al:Al{sub 4}C{sub 3} = 3:2:2 and 3:6:1 successfully produced NbC and Nb{sub 2}C–Al{sub 2}O{sub 3} composites, respectively, with very few minor phases.

  4. Increasing CO[sub 2] from glacial to present concentrations alters nitrogen and water requirements of C[sub 3] plants

    Energy Technology Data Exchange (ETDEWEB)

    Wayne, P.H.; Johnson, H.B.; Mayeux, H.S. (USDA-ARS, Temple, TX (United States))

    1994-06-01

    Nitrogen and water use efficiencies were measured for three C[sub 3] species, annual grasses Bromus tectorum (cheatgrass) and Triticum aestivum (wheat; two cultivars) and a woody perennial Prosopis glandulosa (mesquite), grown at daytime CO[sub 2] concentrations that spanned glacial to present atmospheric levels. Changes in nitrogen and water use efficiencies were used to investigate effects of increasing [CO[sub 2

  5. Asymmetric fission and evaporation of C{sub 60}{sup r+} (r = 2-4) fullerene ions in ion-C{sub 60} collisions: I. Proton results

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A; Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D [LCAR-IRSAMC, UMR 5589 Universite Paul Sabatier-CNRS, 118 rte de Narbonne, 31062 Toulouse Cedex (France)

    2004-06-28

    A quantitative description of the asymmetric fission (AF) of C{sub 60}{sup r+} fullerene ions (r = 2-4), using a multistop coincidence technique between both fragment ions, is presented. Charged light fragment (LF) and heavy fragment (HF) size distributions are discussed together with the corresponding averaged sizes. Complete AF distributions are reported for the first time for C{sub 60}{sup 2+} ions. Simple dependences of the more probable channels and averaged fragment sizes on the partner size are found and discussed. The LF ones are not very sensitive to the parent fullerene ion charge r and vary linearly with the HF size at least for the largest ones. On the other hand the HF ones present an oscillating dependence against the LF size, the odd-numbered LFs being correlated to a smaller HF size, and depend on r. In the comparison of branching ratios between AF and the competing pure neutral evaporation channel, some emphasis is given to the behaviour of the unimolecular processes with r which are compared with the evolution of the activation energies and fission barriers. From a close examination of the individual HF distributions the production mechanisms of odd-n fragments are discussed, and the most probable dissociation channels of even-numbered C{sub n}{sup +} excited carbon clusters identified. Finally, an analysis of the neutral channels is also presented for the first time, the total neutral mass N (in carbon units) being deduced from the mass conservation law. Surprising similarities between the charged LF- and N-distributions are found. AF processes are also identified where light neutrals and ions play a symmetrical role. These findings lead us to suggest that a concerted emission of ions and heavy neutrals is probably a fission mechanism to be considered to understand the AF process of the C{sub 60} molecule in addition to the often assumed multistep fragmentation cascade scheme.

  6. 用于白光LED的Ca2BO3Cl:Eu^2+发光特性研究%Luminescent properties of Ca2BO3Cl:Eu^2+ phosphor for white LED

    Institute of Scientific and Technical Information of China (English)

    李盼来; 徐征; 赵谡玲; 张福俊; 张妍斐

    2012-01-01

    Ca2BO3Cl:Eu2+ yellow phosphor was synthesized by a high temperature solid-state reaction method,and it can be excited by ultraviolet-near ultraviolet and blue light irradiation.The final phase is investigated with the conventional X-ray diffraction(XRD).The spectral characteristics of the phosphor are studied by using a Hitachi F-4600 fluorescence spectrophotometer equipped with a 450 W Xe lamp.The effects of Ce3+,CaCl2 and H3BO3 on the crystal structure and luminescent properties of Ca2BO3Cl:Eu2+ are studied.The results show that its emission intensity can be effectively enhanced by increasing absorption in the region of ultraviolet-near ultraviolet light,which is from the sensitizer Ce3+.The emission intensity of Ca2BO3Cl:Eu2+ can also be enhanced by the excess CaCl2 and H3BO3,and the optimal excess mole concentrations are 5 mol% and 15 mol%,respectively.White LED is fabricated with the phosphor and the 460 nm InGaN LED chip,and the CIE chromaticity coordinate is (0.339,0.351).%采用高温固相法,制备了适于紫外-近紫外及蓝光激发,主峰位于573nm的Ca2BO3Cl:Eu2+黄色荧光粉。研究了Ce3+以及CaCl2和H3BO3用量对材料发光特性等的影响。结果表明,添加Ce3+,明显增强了Ca2BO3Cl:Eu2+材料在紫外-近紫外区的吸收,有效地提高了材料的发射强度;添加过量的CaCl2或H3BO3,均能提高Ca2BO3Cl:Eu2+材料的发射强度,最佳的CaCl2和H3BO3用量分别为过量5mol%和15mol%。将Ca2BO3Cl:Eu2+材料与460nm InGaN芯片组合,获得了白光发射,色坐标为(0.339,0.351)。

  7. The size effects of electrodes in molecular devices: an ab initio study on the transport properties of C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Xiaohong; Dai Zhenxiang; Zeng Zhi [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2009-04-08

    The role of electrodes in the transport properties of molecular devices is investigated by taking C{sub 60} as an example and using gold nanowire and a gold atomic chain as the electrodes. The calculations are done by an ab initio method combined with the non-equilibrium Green function technique. We find that devices in which a single C{sub 60} molecule is connected with different electrodes show completely different transport behavior. In the case of nanowire/C{sub 60}/nanowire the device shows a metallic behavior with a big equilibrium conductance (about 2.18G{sub 0}) and the current increases rapidly and almost linearly starting from zero. The transmission function shows wide peaks and platforms around the Fermi level. While in the atomic-chain/C{sub 60}/atomic-chain case, the device shows resonant tunneling behavior and the Fermi level lies between the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) transmission peaks. This results in a current that is one order of magnitude smaller than that in the nanowire/C{sub 60}/nanowire system and the current increases very slowly until the bias is big enough to include the LUMO peak in the bias window. The big difference in the conductance and the current arises from the different coupling between the electrodes and the C{sub 60} and the different number of channels in the electrodes.

  8. Woodard–Cody anomalous resistivity in a Nb{sub 5}Ge{sub 3}C{sub 0.3} superconductor compound

    Energy Technology Data Exchange (ETDEWEB)

    Bortolozo, Ausdinir D., E-mail: ausdinir.bortolozo@fca.unicamp.br [School of Applied Sciences/FCA, Research Group in Manufacturing of Advanced Materials, University of Campinas, UNICAMP, Campus Limeira, 1300, Pedro Zaccaria St., Jd. Sta Luiza, 13484-350 Limeira, SP (Brazil); Osorio, Wislei R. [School of Applied Sciences/FCA, Research Group in Manufacturing of Advanced Materials, University of Campinas, UNICAMP, Campus Limeira, 1300, Pedro Zaccaria St., Jd. Sta Luiza, 13484-350 Limeira, SP (Brazil); Santos, Carlos Alberto M. dos; Machado, Antônio Jefferson S. [School of Engineering of Lorena –São Paulo University State, P. O. Box 116, Lorena, SP 12600-970 (Brazil)

    2016-08-01

    A normal-state electrical resistivity of a superconducting Nb{sub 5}Ge{sub 3}C{sub 0.3} compound is investigated. Resistivity data are taken from the superconducting transition temperature T{sub c} at room temperature. The data are discussed based on important theoretical expressions in order to explain the normal-state resistivity of the Nb{sub 5}Ge{sub 3}C{sub 0.3} compound. Focusing on the best fitting Woodward and Cody model is used. An 0.77 electron–phonon coupling (λ) is determined, which induces an important role of the electron–phonon coupling for a Nb{sub 5}Ge{sub 3}C{sub 0.3} compound. The saturation of the ρ(T) at 300 K indicates that the mean free path l of the carriers is actually longer than the unit cell dimensions. The negative curvature of this superconductor is a result of the mean free path non-linear in their resulting perturbation. It is also found that the magnitude of the temperature-dependent (phonon) correlated with the resistivity decreases with the decreasing of the mean free path in the absence of phonons due to an atomic disorder induced by lattice intrinsic defects.

  9. Influence of functional groups on the C{sub {alpha}-}C{sub {beta}}chain of L-phenylalanine and its derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, Aravindhan [Centre for Molecular Simulation, Swinburne University of Technology, P.O. Box 218, Hawthorn, Melbourne, Victoria 3122 (Australia); Brunger, Michael [School of Chemistry, Physics and Earth Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Wang Feng, E-mail: fwang@swin.edu.a [Centre for Molecular Simulation, Swinburne University of Technology, P.O. Box 218, Hawthorn, Melbourne, Victoria 3122 (Australia)

    2010-07-21

    L-phenylalanine (L-phe) consists of three different functional groups, i.e., phenyl, carboxyl (-COOH) and amino (-NH{sub 2}), joining through the C{sub {alpha}-}C{sub {beta}}bridge. Substitution of these groups produces 2-phenethylamine (PEA) and 3-phenylpropionic acid (PPA). Electronic structures of L-phe, PEA and PPA together with smaller 'fragments' L-alanine and benzene were determined using density functional theory (DFT), from which core and valence shell ionization spectra were simulated. Comparison of the spectra reveals that core shell ionization energies clearly indicate that the carbon bridge is significantly affected by their functional group substitutions particularly at the C{sub {alpha}}site. In the valence space, quite unexpectedly, the frontier orbitals are concentrated on the benzene group although some energy splitting is observed. The orbitals which significantly affect the C{sub {alpha}-}C{sub {beta}}carbon backbone are from the inner valence shell in the ionization energy region of 20-26 eV of the molecules.

  10. Plasticization effect of C{sub 60} on the fast dynamics of polystyrene and related polymers: an incoherent neutron scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Alejandro; Ruppel, Markus; Cabral, Joao T [Department of Chemical Engineering, Imperial College, London SW7 2AZ (United Kingdom); Douglas, Jack F [Polymers Division, NIST, Gaithersburg, MD 20899 (United States)], E-mail: j.cabral@imperial.ac.uk

    2008-03-12

    We utilize inelastic incoherent neutron scattering (INS) to quantify how fullerenes affect the 'fast' molecular dynamics of a family of polystyrene related macromolecules. In particular, we prepared bulk nanocomposites of (hydrogenous and ring-deuterated) polystyrene and poly(4-methyl styrene) using a rapid precipitation method where the C{sub 60} relative mass fraction ranged from 0% to 4%. Elastic window scan measurements, using a high resolution (0.9 {mu}eV) backscattering spectrometer, are reported over a wide temperature range (2-450 K). Apparent Debye-Waller (DW) factors , characterizing the mean-square amplitude of proton displacements, are determined as a function of temperature, T. We find that the addition of C{sub 60} to these polymers leads to a progressive increase in relative to the pure polymer value over the entire temperature range investigated, where the effect is larger for larger nanoparticle concentration. This general trend seems to indicate that the C{sub 60} nanoparticles plasticize the fast ({approx}10{sup -15} s) local ({approx}1 A) dynamics of these polymer glasses. Generally, we expect nanoparticle additives to affect polymer dynamics in a similar fashion to thin films in the sense that the high interfacial area may cause both a speeding up and slowing down of the glass state dynamics depending on the polymer-surface interaction.

  11. Substrate effects on the analysis of biomolecular layers using Au{sup +}, Au{sub 3}{sup +} and C{sub 60}{sup +} bombardments

    Energy Technology Data Exchange (ETDEWEB)

    Kordys, Jeanette [Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester, M1 7DN (United Kingdom)], E-mail: Jeanette.Soerensen@postgrad.manchester.ac.uk; Fletcher, John S.; Lockyer, Nicholas P.; Vickerman, John C. [Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester, M1 7DN (United Kingdom)

    2008-12-15

    Effects of platinum silicon, graphite and PET substrates on the secondary ion yield of sub-monolayer and multilayer samples of Cyclosporin A following 20 keV Au{sup +}, Au{sub 3}{sup +}and C{sub 60}{sup +} impacts have been investigated. The obtained results of sub-monolayer samples show that platinum enhances the yield of the pseudo-molecular ion following Au{sup +} and Au{sub 3}{sup +} impacts due to the high density of the substrate that enables the energy of the primary ions to be deposited near the surface. C{sub 60}{sup +} impacts on sub-monolayer samples are less effective, but there is an enhancement on PET substrates. Impacts of 20 keV Au{sup +} and Au{sub 3}{sup +} are not very efficient on multilayer samples. 20 keV C{sub 60}{sup +} impacts enhance the yields significantly, especially for the relatively high molecular weight [M+H]{sup +} ion.

  12. Epitaxial growth of 3C-SiC by using C{sub 60} as a carbon source; Untersuchungen zum epitaktischen Wachstum von 3C-SiC bei Verwendung einer C{sub 60}-Kohlenstoffquelle

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, Sascha

    2006-01-15

    Within this work epitaxial 3C-SiC-films were grown on Si(001) substrates and on ion beam synthesized 3C-SiC(001) pseudo substrates. A rather new process was used which is based on the simultaneous deposition of C60 and Si. In order to set up the necessary experimental conditions an ultra-high vacuum chamber has been designed and built. A RHEED system was used to examine SiC film growth in-situ. Using the described technique 3C-SiC films were grown void-free on Si(001) substrates. Deposition rates of C60 and Si were chosen adequately to maintain a Si:C ratio of approximately one during the deposition process. It was shown that stoichiometric and epitaxial 3C-SiC growth with the characteristic relationship (001)[110]Si(001)[110]3C-SiC could be achieved. TEM investigations revealed that the grown 3C-SiC films consist of individual grains that extend from the Si substrate to the film surface. Two characteristic grain types could be identified. The correlation between structure and texture of void-free grown 3C-SiC films and film thickness was studied by X-ray diffraction (XRD). Pole figure measurements showed that thin films only contain first-order 3C-SiC twins. With higher film thickness also second-order twins are found which are located as twin lamellae in grain type 2. Improvement of polar texture with increasing film thickness couldn't be observed in the investigated range of up to 550 nm. On ion beam synthesized 3C-SiC pseudo substrates homoepitaxial 3C-SiC growth could be demonstrated for the first time by using a C{sub 60} carbon source. In respect to the crystalline quality of the grown films the surface quality of the used substrates was identified as a crucial factor. Furthermore a correlation between the ratio of deposition rates of C{sub 60} and Si and 3C-SiC film quality could be found. Under silicon-rich conditions, i.e. with a Si:C ratio of slightly greater one, homoepitaxial 3C-SiC layer-by-layer growth can be achieved. Films grown under these

  13. NAL-Tokyo Institute of Technology: Oxygen concentration on the surface of the solid, C[sub 6]0 are used, and it succeeds in the measurement. Kotai hyomen no sanso nodo, C[sub 60] mochii sokuteini seiko

    Energy Technology Data Exchange (ETDEWEB)

    1998-12-31

    NAL succeeded in oxygen concentration measurement on the surface of the solid which fralen (C[sub 6]0) which was the same base body in cooperation with Tokyo Institute of Technology, biotechnology course as to carbon was used for fralen absorbs light, and materiality to be returned in the condition (base bottom condition) of the place by this activated condition's reacting for the activated condition with oxygen is used. The condition that became of this fralen was used, and oxygen pressure (concentration) developed how to measure it. Oxygen pressure on the surface of the irradiation is measured the light with applying fralen on the surface of the measurement solid and spraying oxygen gas on the application side. So far, 100 points and more of holes were made on the surface of the model, and a pressure sensor was installed, and pressure measurement was being done, and it was as it were the measurement of the meeting body of the point in the aircraft and the wind experiment of the rocket model. The application of fralen, light only irradiates it, and oxygen pressure can be measured easily in the way of measuring it this time. Moreover, it is the measurement of the non-contact and non-destruction side. The illuminant, which makes fralen activated condition again, is sufficient with the visible light, and it is said that it doesn't need to use purple outside light about it. If light can irradiate it again, the surface pressure of which part can be measured, too. (translated by NEDO)

  14. NAL-Tokyo Institute of Technology: Oxygen concentration on the surface of the solid, C{sub 6}0 are used, and it succeeds in the measurement; Kotai hyomen no sanso nodo, C{sub 60} mochii sokuteini seiko

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    NAL succeeded in oxygen concentration measurement on the surface of the solid which fralen (C{sub 6}0) which was the same base body in cooperation with Tokyo Institute of Technology, biotechnology course as to carbon was used for fralen absorbs light, and materiality to be returned in the condition (base bottom condition) of the place by this activated condition`s reacting for the activated condition with oxygen is used. The condition that became of this fralen was used, and oxygen pressure (concentration) developed how to measure it. Oxygen pressure on the surface of the irradiation is measured the light with applying fralen on the surface of the measurement solid and spraying oxygen gas on the application side. So far, 100 points and more of holes were made on the surface of the model, and a pressure sensor was installed, and pressure measurement was being done, and it was as it were the measurement of the meeting body of the point in the aircraft and the wind experiment of the rocket model. The application of fralen, light only irradiates it, and oxygen pressure can be measured easily in the way of measuring it this time. Moreover, it is the measurement of the non-contact and non-destruction side. The illuminant, which makes fralen activated condition again, is sufficient with the visible light, and it is said that it doesn`t need to use purple outside light about it. If light can irradiate it again, the surface pressure of which part can be measured, too. (translated by NEDO)

  15. Scaling of C{sub 60} ionization and fragmentation with the energy deposited in collisions with H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} ions (2-130 keV)

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, D. [LCAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)]. E-mail: dbm@yosemite.ups-tlse.fr; Moretto-Capelle, P.; Bordenave-Montesquieu, A.; Rentenier, A. [LCAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)

    2001-03-14

    Fragmentation, ionization and C{sub 2} fragment evaporation of the C{sub 60} molecule induced by collisions with H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} monocharged ions have been measured in coincidence with the electron emission in the 2-130 keV projectile energy range. The time-of-flight mass spectra were found to vary strongly with the collision energy or velocity and the projectile. On the other hand, they scale rather nicely with the energy deposited in the molecule. Relative weights of the total multi-fragmentation into small C{sub n}{sup +} fragments (n=1-14), individual multi-fragmentation (n=1,7 and 11), double ionization of the intact molecule and evaporation of C{sub 2} molecules associated with the doubly charged fullerene ion, are used to illustrate our finding quantitatively. (author). Letter-to-the-editor.

  16. A Modified Potential Method for Electrons Scattering Total Cross Section Calculations on Several Molecules at 30 ~ 5000 eV: CF4, CCl4, CFCl3, CF2Cl2, and CF3Cl

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A complex optical model potential modified by the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds between two atoms in a molecule, is employed to calculate the total cross sections (TCSs) for electrons scattering from several molecules (CF4, CCl4, CFCl3, CF2 Cl2, and CF3 Cl) over an incident energy range 30 ~ 5000 eV using the additivity rule model at Hartree-Fock level. The quantitative TCSs are compared with those obtained by experiments and other theories wherever available, and good agreement is obtained above 100 eV.It is shown that the modified potential can successfully calculate the TCSs of electron-molecule scattering over a wide energy range, especially at lower energies.

  17. COPOLYMERIZATION OF BUTADIENE AND ISOPRENE CATALYZED BY V(acac)3 -Al(i-Bu)2 Cl-Al2Et3Cl3 CATALYST AND CHARACTERIZATION OF THE PRODUCTS

    Institute of Scientific and Technical Information of China (English)

    HU Zhenya; WEI Jinzhu; YANG Jipo; LI Xiaoyan

    1984-01-01

    Copolymerization of butadiene and isoprene catalyzed by the catalyst system V(acac)3-Al(i-Bu)2Cl-Al2Et3Cl3 has been studied. Composition, microstructure, crystallinity and melting point of the copolymer obtained were determined by PGC, IR, X-ray diffraction and DSC methods respectively. The results revealed that the product was a copolymer and not a blend. The butadiene units presented in the copolymer were of trans-1,4-configuration, while the isoprene units were of both trans-1,4- and 3,4- forms. The melting point and crystallinity of the copolymer decreased with increase of molar ratio of isoprene to butadiene.

  18. Characteristics of carbon coatings on optical fibers prepared by radio-frequency plasma enhanced chemical vapor deposition with different H{sub 2}/C{sub 2}H{sub 2} ratios

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Hung-Chien; Yu, Jen-Feng [Department of Materials Science and Engineering, National Chung Hsing University 250 Kuo Kuang Road, Taichung 402, Taiwan (China); Shiue, Sham-Tsong, E-mail: stshiue@dragon.nchu.edu.t [Department of Materials Science and Engineering, National Chung Hsing University 250 Kuo Kuang Road, Taichung 402, Taiwan (China); Lin, Hung-Yi [Mechanical and Systems Research Laboratories, Industrial Technology Research Institute, Hsinchu 310, Taiwan (China)

    2010-10-01

    Characteristics of carbon coatings on optical fibers prepared by radio-frequency plasma enhanced chemical vapor deposition with different H{sub 2}/C{sub 2}H{sub 2} ratios are investigated. Five kinds of carbon coatings are prepared with H{sub 2}/C{sub 2}H{sub 2} ratios of 2, 4, 6, 8, and 10. Experimental results show that the deposition rate and surface roughness of carbon coatings decrease as the H{sub 2}/C{sub 2}H{sub 2} ratio increases. When the H{sub 2}/C{sub 2}H{sub 2} ratio changes from 2 to 8, the increase of H{sub 2}/C{sub 2}H{sub 2} ratios detrimentally yields sp{sup 3} carbon atoms and sp{sup 3}-CH{sub 3} bonds in the carbon coatings. However, when the H{sub 2}/C{sub 2}H{sub 2} ratio exceeds 8, the hydrogen retards the growth of the graphite structure. Moreover, the redundant hydrogen radicals favor bonding with the dangling bonds in the coating surface. Therefore, when the H{sub 2}/C{sub 2}H{sub 2} ratio increases from 8 to 10, the amounts of sp{sup 3} carbon atoms and sp{sup 3}-CH{sub 3} bonds in the carbon coatings increase. At an H{sub 2}/C{sub 2}H{sub 2} ratio of 8, the carbon coating exhibits excellent water-repellency and thermal-loading resistance, and so this ratio is the best for producing a hermetically sealed optical fiber coating.

  19. Fast Energy Transfer and Molecular Dynamics in the Electronic Ground State Of C{sub 2}H{sub 2} and H{sub 2}CO Viewed By Time Resolved FS-CARS

    Energy Technology Data Exchange (ETDEWEB)

    Knopp, G.; Beaud, P.; Radi, P.; Tulej, M.; Gerber, T.

    2004-03-01

    The molecular dynamics in the electronic ground state of C{sub 2}H{sub 2} and of H{sub 2}CO have been interrogated by the femto second CARS method. For a discussion of collision induced rotational and vibrational energy transfer in the electronic ground state of the polyatomic acetylene (C{sub 2H}2) molecule the transient signals were evaluated with the recently developed angular momentum and energy corrected scaling law. (author)

  20. Layered perovskite-related ruthenium oxychlorides: crystal structure of two new compounds Ba 5Ru 2Cl 2O 9 and Ba 6Ru 3Cl 2O 12

    Science.gov (United States)

    Tancret, N.; Roussel, P.; Abraham, F.

    2004-03-01

    Single crystals of the title compounds were prepared using a BaCl 2 flux and investigated by X-ray diffraction methods using Mo Kα radiation and a charge coupled device (CCD) detector. The crystal structures of these two new compounds were solved and refined in the hexagonal symmetry with space group P6 3/ mmc, a=5.851(1) Å, c=25.009(5) Å, ρcal=4.94 g cm -3, Z=2 to a final R1=0.069 for 20 parameters with 312 reflections for Ba 5Ru 2Cl 2O 9 and space group P 3¯m1 , a=5.815(1) Å, c=14.915(3) Å, ρcal=5.28 g cm -3, Z=1 to a final R1=0.039 for 24 parameters with 300 reflections for Ba 6Ru 3Cl 2O 12. The structure of Ba 5Ru 2Cl 2O 9 is formed by the periodic stacking along [001] of three hexagonal close-packed BaO 3 layers separated by a double layer of composition Ba 2Cl 2. The BaO 3 stacking creates binuclear face-sharing octahedra units Ru 2O 9 containing Ru(V). The structure of Ba 6Ru 3Cl 2O 12 is built up by the periodic stacking along [001] of four hexagonal close-packed BaO 3 layers separated by a double layer of composition Ba 2Cl 2. The ruthenium ions with a mean oxidation degree +4.67 occupy the octahedral interstices formed by the four layers hexagonal perovskite slab and then constitute isolated trinuclear Ru 3O 12 units. These two new oxychlorides belong to the family of compounds formulated as [Ba 2Cl 2][Ba n+1 Ru nO 3 n+3 ], where n represents the thickness of the octahedral string in hexagonal perovskite slabs.

  1. A kinetics study of the O({sup 3}P) + CH{sub 3}Cl reaction over the 556-1485 K range by the HTP and LP-ST techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Taeho; Fontijn, A. [Rensselaer Polytechnic Inst., Troy, NY (United States). High-Temperature Reaction Kinetics Lab.; Lim, K.P.; Michael, J.V. [Argonne National Lab., IL (United States)

    1991-12-01

    The high-temperature photochemistry (HTP) and laser photolysis-shock tube (LP-ST) techniques have been combined to study the kinetics of the reaction between ground-state oxygen atoms with CH{sub 3}Cl over the temperature range, 556--1485 K. In the HTP reactor, used for the 556--1291 K range, O atoms were generated by flash photolysis of O{sub 2}, CO{sub 2} or SO{sub 2}, and the atom concentrations were monitored by resonance fluorescence, while with the LP-ST technique, used for the 916--1485 K range, O atoms were generated by the photolysis of either SO{sub 2} or NO with the 193 nm light from a pulsed ArF excimer laser, and atomic resonance absorption spectroscopy (ARAS) was used to monitor [O]{sub t}. In both studies, rate coefficients were derived from the [O] profiles under the pseudo-first-order condition, [O]{much_lt}[CH{sub 3}Cl]. The data obtained by the two techniques are in excellent agreement and are best represented by the expression, k(T) = 2.57 {times} 10{sup {minus}11} (T/K){sup 0.31} exp({minus}5633 K/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} with a 2{sigma} precision varying from {plus_minus}6 {plus_minus}22% and an estimated 2{sigma} accuracy of {plus_minus}21% to {plus_minus}30%, depending on temperature. The rate coefficients for the title reaction are essentially identical to those for the O + CH{sub 4} reaction over the observed temperature range, the reasons for which are discussed.

  2. A kinetics study of the O( sup 3 P) + CH sub 3 Cl reaction over the 556-1485 K range by the HTP and LP-ST techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Taeho; Fontijn, A. (Rensselaer Polytechnic Inst., Troy, NY (United States). High-Temperature Reaction Kinetics Lab.); Lim, K.P.; Michael, J.V. (Argonne National Lab., IL (United States))

    1991-12-01

    The high-temperature photochemistry (HTP) and laser photolysis-shock tube (LP-ST) techniques have been combined to study the kinetics of the reaction between ground-state oxygen atoms with CH{sub 3}Cl over the temperature range, 556--1485 K. In the HTP reactor, used for the 556--1291 K range, O atoms were generated by flash photolysis of O{sub 2}, CO{sub 2} or SO{sub 2}, and the atom concentrations were monitored by resonance fluorescence, while with the LP-ST technique, used for the 916--1485 K range, O atoms were generated by the photolysis of either SO{sub 2} or NO with the 193 nm light from a pulsed ArF excimer laser, and atomic resonance absorption spectroscopy (ARAS) was used to monitor (O){sub t}. In both studies, rate coefficients were derived from the (O) profiles under the pseudo-first-order condition, (O){much lt}(CH{sub 3}Cl). The data obtained by the two techniques are in excellent agreement and are best represented by the expression, k(T) = 2.57 {times} 10{sup {minus}11} (T/K){sup 0.31} exp({minus}5633 K/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} with a 2{sigma} precision varying from {plus minus}6 {plus minus}22% and an estimated 2{sigma} accuracy of {plus minus}21% to {plus minus}30%, depending on temperature. The rate coefficients for the title reaction are essentially identical to those for the O + CH{sub 4} reaction over the observed temperature range, the reasons for which are discussed.

  3. Treatment of diabetic mice with undenatured whey protein accelerates the wound healing process by enhancing the expression of MIP-1α, MIP-2, KC, CX3CL1 and TGF-β in wounded tissue

    Directory of Open Access Journals (Sweden)

    Badr Gamal

    2012-06-01

    Full Text Available Abstract Background Continuous diabetes-associated complications are a major source of immune system exhaustion and an increased incidence of infection. Diabetes can cause poor circulation in the feet, increasing the likelihood of ulcers forming when the skin is damaged and slowing the healing of the ulcers. Whey proteins (WPs enhance immunity during childhood and have a protective effect on some immune disorders. Therefore, in this study, we investigated the effects of camel WP on the healing and closure of diabetic wounds in a streptozotocin (STZ-induced type I diabetic mouse model. Results Diabetic mice exhibited delayed wound closure characterized by a significant decrease in an anti-inflammatory cytokine (namely, IL-10 and a prolonged elevation of the levels of inflammatory cytokines (TNF-α, IL-1β and IL-6 in wound tissue. Moreover, aberrant expression of chemokines that regulate wound healing (MIP-1α, MIP-2, KC and CX3CL1 and growth factors (TGF-β were observed in the wound tissue of diabetic mice compared with control nondiabetic mice. Interestingly, compared with untreated diabetic mice, supplementation with WP significantly accelerated the closure of diabetic wounds by limiting inflammatory stimuli via the restoration of normal IL-10, TNF-α, IL-1β and IL-6 levels. Most importantly, the supplementation of diabetic mice with WP significantly modulated the expression of MIP-1α, MIP-2, KC, CX3CL1 and TGF-β in wound tissue compared with untreated diabetic mice. Conclusion Our data demonstrate the benefits of WP supplementation for improving the healing and closure of diabetic wounds and restoring the immune response in diabetic mice.

  4. Radiation use efficiency and leaf CO{sub 2} exchange for diverse C{sub 4} grasses

    Energy Technology Data Exchange (ETDEWEB)

    Kiniry, J.R.; Tischler, C.R. [USDA, Agricultural Research Service, Temple, TX (United States); Van Esbroeck, G.A. [North Carolina State University, Raleigh (United States). Dept. of Crop Science

    1999-08-01

    Biomass accumulation of different grass species can be quantified by leaf area index (LAI) development, the Beer-Lambert light interception function, and a species-specific radiation-use efficiency (RUE). The object of this field study was to compare RUE values and leaf CO{sub 2} exchange rates (CER) for four C{sub 4} grasses. Biomass, LAI and fraction of photosynthetically active radiation (PAR) intercepted were measured during three growing seasons. CER was measured on several dates and at several positions in the canopies. Switchgrass (Panicum virgatum L.) had the greatest RUE whereas sideoats grama (Bouteloua curtipendula (Michaux) Torrey) had the lowest. Big bluestem (Andropogon gerardii Vitman) and eastern gamagrass (Tripsacum dactyloides (L.) L.) values were intermediate. The two species with the greatest differences in RUE, switch grass and sideoats grama, had similar relative amounts partitioned to roots. Likewise differences among species in the accumulation of soil carbon showed trends similar to total shoot biomass production. The light extinction coefficients ({kappa}) of switchgrass, big bluestem, and eastern gamagrass were smaller than for sideoats grama, implying that light was more effectively scattered down into the leaf canopy of the first three grasses. Whole canopy CER values were calculated with a stratified canopy approach, using LAI values, the Beer-Lambert formula with appropriate extinction coefficients, and CER light response curves. Differences among species in RUE were similar to these values for estimated whole-canopy CER divided by the fraction of light that was intercepted. High lAI along with low {kappa} contributed to higher RUE in switchgrass, in spite of lower values for single-leaf CER.

  5. Effects of polarizability on the structural and thermodynamics properties of [C{sub n}mim][Gly] ionic liquids (n = 1–4) using EEM/MM molecular dynamic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yang; Hu, Na; Yue, Lili; Wei, Lihong; Guan, Wei [Key Laboratory of Green Synthesis and Preparative Chemistry of Advanced Materials, College of Chemistry, Liaoning University, Shenyang 110036 (China)

    2015-02-14

    An extended electronegativity equalization method/molecular mechanics (EEM/MM) model for ionic liquids is used to investigate the structures and properties of 1-alkyl-3-methylimidazolium glycine ionic liquids [C{sub n}mim][Gly] (n = 1–4) with alkyl substituents of different lengths. The EEM/MM model describes the electrostatic interactions of atoms and their changes in different ambient environments. This property is the most outstanding characteristic of the model. EEM parameters (i.e., valence electronegativities and valence hardness parameters) are calibrated using linear regression and least-squares methods, which can accurately predict the gas-phase properties of [C{sub n}mim]{sup +}, [Gly]{sup −}, and [C{sub n}mim][Gly] ion pairs. We utilize the EEM/MM force field to systematically investigate the effects of polarizability on the accuracy of [C{sub n}mim][Gly] properties predicted through the molecular dynamic simulations. EEM/MM explicitly describes the atom-based polarizability of [C{sub n}mim][Gly]; thus, the densities, enthalpies of vaporization, self-diffusion coefficients, and conductivities of the [C{sub n}mim][Gly] are consistent with the experimental values. The calculated radial distribution functions provide a mechanistic understanding of the effects of polarizability on ionic aggregations in amino acid ionic liquids. The effects of alkyl chain length on the diffusion coefficient and conductivity are also discussed.

  6. Distortion of ethyne on coordination to silver acetylide, C{sub 2}H{sub 2}⋅⋅⋅AgCCH, characterised by broadband rotational spectroscopy and ab initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Susanna L.; Zaleski, Daniel P.; Walker, Nicholas R., E-mail: nick.walker@newcastle.ac.uk, E-mail: a.c.legon@bristol.ac.uk [School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, Tyne and Wear NE1 7RU (United Kingdom); Mizukami, Wataru; Tew, David P.; Legon, Anthony C., E-mail: nick.walker@newcastle.ac.uk, E-mail: a.c.legon@bristol.ac.uk [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom)

    2014-03-28

    The rotational spectra of six isotopologues of a complex of ethyne and silver acetylide, C{sub 2}H{sub 2}⋅⋅⋅AgCCH, are measured by both chirped-pulse and Fabry-Perot cavity versions of Fourier-transform microwave spectroscopy. The complex is generated through laser ablation of a silver target in the presence of a gas sample containing 1% C{sub 2}H{sub 2}, 1% SF{sub 6}, and 98% Ar undergoing supersonic expansion. Rotational, A{sub 0}, B{sub 0}, C{sub 0}, and centrifugal distortion Δ{sub J} and Δ{sub JK} constants are determined for all isotopologues of C{sub 2}H{sub 2}⋅⋅⋅AgCCH studied. The geometry is planar, C{sub 2v} and T-shaped in which the C{sub 2}H{sub 2} sub-unit comprises the bar of the “T” and binds to the metal atom through its π electrons. In the r{sub 0} geometry, the distance of the Ag atom from the centre of the triple bond in C{sub 2}H{sub 2} is 2.2104(10) Å. The r(HC≡CH) parameter representing the bond distance separating the two carbon atoms and the angle, ∠(CCH), each defined within the C{sub 2}H{sub 2} sub-unit, are determined to be 1.2200(24) Å and 186.0(5)°, respectively. This distortion of the linear geometry of C{sub 2}H{sub 2} involves the hydrogen atoms moving away from the silver atom within the complex. The results thus reveal that the geometry of C{sub 2}H{sub 2} changes measurably on coordination to AgCCH. A value of 59(4) N m{sup −1} is determined for the intermolecular force constant, k{sub σ}, confirming that the complex is significantly more strongly bound than hydrogen and halogen-bonded analogues. Ab initio calculations of the r{sub e} geometry at the CCSD(T)(F12{sup *})/ACVTZ level of theory are consistent with the experimental results. The spectra of the {sup 107}Ag{sup 13}C{sup 13}CH and {sup 109}Ag{sup 13}C{sup 13}CH isotopologues of free silver acetylide are also measured for the first time allowing the geometry of the AgCCH monomer to be examined in greater detail than previously.

  7. The underlying electrode causes the reported 'electro-catalysis' observed at C{sub 60}-modified glassy carbon electrodes in the case of N-(4-hydroxyphenyl)ethanamide and salbutamol

    Energy Technology Data Exchange (ETDEWEB)

    Griese, Sebastian; Kampouris, Dimitrios K.; Kadara, Rashid O.; Banks, Craig E. [Faculty of Science and Engineering, School of Biology, Chemistry and Health Science, Division of Chemistry and Materials, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, Lancs (United Kingdom)

    2008-08-20

    The reported 'electro-catalysis' of C{sub 60}-film-modified electrodes for the electrochemical oxidation of N-(4-hydroxyphenyl)ethanamide and salbutamol has been explored at boron-doped diamond and glassy carbon electrodes. Using both C{sub 60}-film-modified boron-doped diamond and glassy carbon as underlying electrode substrates no electro-catalytic response is observed using the target analytes but rather the C{sub 60} serves to block the electrode surface. A common experimental protocol used by researchers in this field is to electrochemically pre-treat the C{sub 60}-film-modified electrode. The response of employing this electrochemical pre-treatment at both bare glassy carbon and boron-doped diamond electrodes using the target analytes reveals that no effect on the electrochemical responses obtained at the boron-doped diamond electrode whereas a slight but significant effect occurs on glassy carbon which is attributed to the likely introduction of surface oxygenated species. Consequently the previously reported 'electro-catalysis' using C{sub 60}-film-modified electrode is not due to C{sub 60} itself being catalytic, but rather that substrate activation through electrode pre-treatment is responsible for the observed 'electro-catalysis' likely through the introduction of surface oxygenated species. This work clearly shows that substrate activation is an important parameter which researchers studying C{sub 60}-film-modified electrodes, especially in electro-analysis needs to be considered. (author)

  8. Deposition, Accumulation, and Alteration of Cl(-), NO3(-), ClO4(-) and ClO3(-) Salts in a Hyper-Arid Polar Environment: Mass Balance and Isotopic Constraints

    Science.gov (United States)

    Jackson, Andrew; Davila, Alfonso F.; Boehlke, J. K.; Sturchio, Neil C.; Sevanthi, Ritesh; Estrada, Nubia; Brundrette, Megan; Lacell, Denis; McKay, Christopher P.; Poghosyan, Armen; text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20160009066'); toggleEditAbsImage('author_20160009066_show'); toggleEditAbsImage('author_20160009066_hide'); "> hide

    2016-01-01

    The salt fraction in permafrost soils/sediments of the McMurdo Dry Valleys (MDV) of Antarctica can be used as a proxy for cold desert geochemical processes and paleoclimate reconstruction. Previous analyses of the salt fraction in MDV permafrost soils have largely been conducted in coastal regions where permafrost soils are variably affected by aqueous processes and mixed inputs from marine and stratospheric sources. We expand upon this work by evaluating permafrost soil/sediments in University Valley, located in the ultraxerous zone where both liquid water transport and marine influences are minimal. We determined the abundances of Cl(-), NO3(-, ClO4(-)and ClO3(-)in dry and ice-cemented soil/sediments, snow and glacier ice, and also characterized Cl(-) and NO3(-) isotopically. The data are not consistent with salt deposition in a sublimation till, nor with nuclear weapon testing fall-out, and instead point to a dominantly stratospheric source and to varying degrees of post depositional transformation depending on the substrate, from minimal alteration in bare soils to significant alteration (photodegradation and/or volatilization) in snow and glacier ice. Ionic abundances in the dry permafrost layer indicate limited vertical transport under the current climate conditions, likely due to percolation of snowmelt. Subtle changes in ClO4(-)/NO3(-) ratios and NO3(-) isotopic composition with depth and location may reflect both transport related fractionation and depositional history. Low molar ratios of ClO3(-)/ClO4(-) in surface soils compared to deposition and other arid systems suggest significant post depositional loss of ClO3(-), possibly due to reduction by iron minerals, which may have important implications for oxy-chlorine species on Mars. Salt accumulation varies with distance along the valley and apparent accumulation times based on multiple methods range from approximately 10 to 30 kyr near the glacier to 70-200 kyr near the valley mouth. The relatively

  9. Protectin D1 reduces concanavalin A-induced liver injury by inhibiting NF-κB-mediated CX3CL1/CX3CR1 axis and NLR family, pyrin domain containing 3 inflammasome activation.

    Science.gov (United States)

    Ren, Jun; Meng, Shanshan; Yan, Bingdi; Yu, Jinyan; Liu, Jing

    2016-04-01

    Protectin D1 (PD1) is a bioactive product generated from docosahexaenoic acid, which may exert anti-inflammatory effects in various inflammatory diseases. However, the underlying molecular mechanism of its anti‑inflammatory activity on concanavalin A (Con A)-induced hepatitis remains unknown. The aim of the present study was to investigate the protective effects of PD1 against Con A‑induced liver injury and the underlying mechanisms via intravenous injection of PD1 prior to Con A administration. C57BL/6 mice were randomly divided into four experimental groups as follows: Control group, Con A group (30 mg/kg), 20 µg/kg PD1 + Con A (30 mg/kg) group and 10 µg/kg PD1 + Con A (30 mg/kg) group. PD1 pretreatment was demonstrated to significantly inhibit elevated plasma aminotransferase levels, high mobility group box 1 and liver necrosis, which were observed in Con A‑induced hepatitis. Furthermore, compared with the Con A group, PD1 pretreatment prevented the production of pro‑inflammatory cytokines, including tumor necrosis factor‑α, interferon‑γ and interleukin‑2, ‑1β and ‑6. In addition, pretreatment with PD1 markedly downregulated cluster of differentiation (CD)4+, CD8+ and natural killer T (NKT) cell infiltration in the liver. PD1 pretreatment was observed to suppress the messenger RNA and protein expression levels of NLR family, pyrin domain containing 3 and Toll‑like receptor (TLR) 4 in liver tissue samples. Further data indicated that PD1 pretreatment inhibited the activation of the nuclear factor κ‑light‑chain‑enhancer of activated B cells (NF‑κB) signaling pathway and chemokine (C‑X3‑C motif) ligand 1 (CX3CL1)/chemokine (C-X3-C motif) receptor 1 (CX3CR1) axis by preventing phosphorylation of nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor, α and NF‑κB in Con A‑induced liver injury. Therefore, these results suggest that PD1 administration protects mice against Con A‑induced liver injury via

  10. Deposition, accumulation, and alteration of Cl-, NO3-, ClO4- and ClO3- salts in a hyper-arid polar environment: Mass balance and isotopic constraints

    Science.gov (United States)

    Jackson, Andrew; Davila, Alfonso F.; Böhlke, John Karl; Sturchio, Neil C.; Sevanthi, Ritesh; Estrada, Nubia; Brundrett, Maeghan; Lacelle, Denis; McKay, Christopher P.; Poghosyan, Armen; Pollard, Wayne; Zacny, Kris

    2016-06-01

    The salt fraction in permafrost soils/sediments of the McMurdo Dry Valleys (MDV) of Antarctica can be used as a proxy for cold desert geochemical processes and paleoclimate reconstruction. Previous analyses of the salt fraction in MDV permafrost soils have largely been conducted in coastal regions where permafrost soils are variably affected by aqueous processes and mixed inputs from marine and stratospheric sources. We expand upon this work by evaluating permafrost soil/sediments in University Valley, located in the ultraxerous zone where both liquid water transport and marine influences are minimal. We determined the abundances of Cl-, NO3-, ClO4- and ClO3- in dry and ice-cemented soil/sediments, snow and glacier ice, and also characterized Cl- and NO3- isotopically. The data are not consistent with salt deposition in a sublimation till, nor with nuclear weapon testing fall-out, and instead point to a dominantly stratospheric source and to varying degrees of post depositional transformation depending on the substrate, from minimal alteration in bare soils to significant alteration (photodegradation and/or volatilization) in snow and glacier ice. Ionic abundances in the dry permafrost layer indicate limited vertical transport under the current climate conditions, likely due to percolation of snowmelt. Subtle changes in ClO4-/NO3- ratios and NO3- isotopic composition with depth and location may reflect both transport related fractionation and depositional history. Low molar ratios of ClO3-/ClO4- in surface soils compared to deposition and other arid systems suggest significant post depositional loss of ClO3-, possibly due to reduction by iron minerals, which may have important implications for oxy-chlorine species on Mars. Salt accumulation varies with distance along the valley and apparent accumulation times based on multiple methods range from ∼10 to 30 kyr near the glacier to 70-200 kyr near the valley mouth. The relatively young age of the salts and

  11. BiOBr/protonated graphitic C{sub 3}N{sub 4} heterojunctions: Intimate interfaces by electrostatic interaction and enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhichong; Li, Jun; Cheng, Fuxing [Department of Chemistry, School of Sciences, Zhejiang Sci-Tech University, 928 Second Avenue, Xiasha Higher Education Zone, Hangzhou 310018 (China); Chen, Zhi [College of Materials Science and Engineering, China Jiliang University, 258 Xueyuan Street, Xiasha Higher Education Zone, Hangzhou 310018 (China); Dong, Xiaoping, E-mail: xpdong@zstu.edu.cn [Department of Chemistry, School of Sciences, Zhejiang Sci-Tech University, 928 Second Avenue, Xiasha Higher Education Zone, Hangzhou 310018 (China)

    2015-06-15

    Highlights: • BiOBr/pg-C{sub 3}N{sub 4} was prepared by an electrostatically-driven in-situ growth method. • BiOBr/pg-C{sub 3}N{sub 4} exhibited a superior visible-light activity and stability. • The efficient separation of charges due to the intimate interface of BiOBr/pg-C{sub 3}N{sub 4}. - Abstract: In this work, enhanced photocatalytic activity of BiOBr/graphitic C{sub 3}N{sub 4} heterojunctions for degradation of Rhodamine B (RhB) were obtained by the protonation pretreatment of graphitic C{sub 3}N{sub 4} with hydrochloric acid. A possibly electrostatic interaction between protonated graphitic C{sub 3}N{sub 4} (pg-C{sub 3}N{sub 4}) and BiOBr provided a closely intimate interface in the heterojunction, which was demonstrated by the results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). This tight coupling was favorable for the charge transfer between pg-C{sub 3}N{sub 4} and BiOBr, and therefore promoted the effective separation of photogenerated electron–hole pairs. The effect of composition in heterojunctions on photocatalytic activity was investigated, and the optimal photocatalyst with a BiOBr/pg-C{sub 3}N{sub 4} mass ratio of 7:3 showed a superior activity, which was 35.03 and 33.72 times higher than that over pg-C{sub 3}N{sub 4} and BiOBr, respectively. Radical trap experiments confirmed that the holes and superoxide radical species were the main reactive species in the RhB photodegradation process. Moreover, the stability of BiOBr/pg-C{sub 3}N{sub 4} heterojunction was also tested and the RhB degradation efficiency declined by only 9.6% after seven successive cycles.

  12. High negative ion production yield in 30 keV F{sup 2+} + adenine (C{sub 5}H{sub 5}N{sub 5}) collisions

    Energy Technology Data Exchange (ETDEWEB)

    Li, B; Ma, X; Zhu, X L; Zhang, S F; Liu, H P; Feng, W T; Qian, D B; Zhang, D C [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Chen, L; Bredy, R; Montagne, G; Bernard, J; Martin, S [Universite de Lyon, F-69622, Lyon (France) and Universite Lyon 1, Villeurbanne; CNRS, UMR5579, LASIM (France)], E-mail: chen@univ-lyon1.fr

    2009-04-14

    In collisions between slow F{sup 2+} ions (30 keV) and molecular targets, adenine, scattered particle production yields have been measured directly by simultaneous detection of neutrals, positive and negative ions. The relative cross-section for a negative ion formation channel was measured to be 1%. Despite a slight decrease compared to a larger target, the fullerene C{sub 60}, the measured negative ion formation cross section is still at least one order of magnitude larger than the yield in ion-atom interactions.

  13. A empiric expression to interpret the approximation of {lambda} cI phages to E. coli C{sub 6}00 bacteria; Determinacion experimental de la cinetica de laproximacion del fago /{lambda}cl a la bacteria E. coli C{sub 6}00 Expression empirica interpretativa del proceso

    Energy Technology Data Exchange (ETDEWEB)

    Garces, F.; Vidania, R. de

    1984-07-01

    In general the process of adsorption of phages to bacteria is considered in the bibliography as an statistical process. In this work we use an empiric expression which allows to interpret the approximation of {lambda}cI pages to E. coli C{sub 6}00 bacteria. This expression introduces some changes respect to a pure statistical description of the approximation process. (Author) 26 refs.

  14. 用代数哈米顿量研究CH3C1分子的振动谱%Algebraic Hamiltonian for vibrational spectra of molecule CH3Cl

    Institute of Scientific and Technical Information of China (English)

    龚福明; 万明芳; 侯喜文

    2007-01-01

    An algebraic Hamiltonian describing both stretching and bending vibrational energy levels of molecule XH3 is presented,where Fermi resonance couplings between the stretch and bend modes are included.The Hamiltonian is employed to fit the observed vibrational spectra of CH3Cl.The result shows that the algebraic Hamiltonian with few parameters reproduces the observed experimental values with smaller standard deviation than other model.%我们提出一种描述XH3分子的伸缩和弯曲振动的U(2)代数哈米顿量,其中包括了伸缩和弯曲振动的费米共振耦合;用它来拟合CH3Cl分子的实验数据,结果表明有较少参数的代数模型算得的偏差比其它模型算得的偏差要小.

  15. Lanthanide Complex[Xd(dpdo)4(H2O)3][ClO4]3·4.5H2O·dpdo Containing Framework Based on 4,4′—Dipyradine—Dioxide

    Institute of Scientific and Technical Information of China (English)

    马宝清; 孙豪岭; 等

    2002-01-01

    A novel lanthanide coordination polymer formulated as [Nd(dpdo)4(H2O)3][ClO4]4·4.5H2O·dpdo1(dpdo=4,4′-dipyrazine-dioxide)was synthesized and structurally characterized.The Nd3+ions are bridged by dpdo ligands in a cis-mode to form a zigzag chain along[001]direction.Meanwhile,each Nd3+ion is coordinated with three terminal dpdo molecules.One of them is overlapped with the bridging one throughπ-πstackings,and the orher wto are bound to the opposite directions of the bridging ones,producing a ribbon-like motif with rectangular cavity,These adjacent ribbons are connected thorough inter-molecularπ-πstackings to give parquet-like architecture with a large rectangular channel(1.108nm×1.660nm)in which the crystal lattice water molecules and ClO-4anions are included.Thermalanalysis shows that the solvate dpdo and water molecules can be removed at lower temperature,while coordinated dpdo molecules are lost simultaneously at higher temperature.

  16. Structure of Bischloro tris( 1,10-phenanthroline)copper(Ⅱ) Dichloromethane Solvate Nonahydrate:[ Cu(phen) 3] Cl2· CH2Cl2· 9H2O

    Institute of Scientific and Technical Information of China (English)

    JIAN,Fang-Fang(建方方); LIN,Jie-Hua(林洁华); ZHANG,Shu-Sheng(张书圣)

    2001-01-01

    The crystal and molecular structures of [ Cu ( phen )3 ] Cl2 · CH2Cl2·9H2O (PHEN= 1,10+phenanthroline) have been de-termined by X-ray crystallogyaphy. The complex crystallizes in triclinic system, space group P-1,with lattice paramaters a=1.26000(3), b = 1.37525(4), c = 1.42750(3)nm, α=85.2970(1),β=66.8400(1), γ= 83.09(1)°, and Z=2. The coordinated cations contain a six-coordinated copper atom chelated by three PHEN ligands, and the Jahn-Teller effecdt of the Cu(Ⅱ) ion results in adistorted octahedral arrangement with the six Cu-N distances ranging from 0.2112(6) to 0.2265(7) nm. In addition to the copper coordinated cation, there are two chloride ions, one dichloromethane solvate and nine water molecules in its asymmetric unit.In the solid state,the title compund forms three dimensional network structures through hydrogen bonds, The intermolecular hydrogen bonds connect the [Cu(phen)3]2+, chloride ion, dichloromethane solvate and H2O moietties altogether.

  17. Influence of cation substitution on the crystal structure and luminescent properties in apatite structural Ba4.97-xSrx(PO4)3Cl:0.03Eu2+ phosphors

    Science.gov (United States)

    Zhu, Ling; Huang, Zhaohui; Molokeev, Maxim S.; Min, Xin; Liu, Yangai; Fang, Minghao; Wu, Xiaowen

    2016-08-01

    A series of apatite-type phosphors Ba4.97-xSrx(PO4)3Cl:Eu2+(x = 0, 0.5, 1.0, 1.5, 2.0) were synthesized by the high temperature solid-state reaction method, and its luminescence properties were investigated in detail. It can be found that a red shift of the emission peak wavelength emerged from 439 to 462 nm with the continuous introduction of Sr2+ into the crystal lattice which has been simulated by a crystal-field model. The red shift is explained by the distortion in the crystal structure through X-ray diffraction and the Rietveld refinement analysis. According to a recently raised structural model, Eu2+ ions are surrounded by O atoms, PO4 tetrahedrons and Ba/Sr ions. After introducing Sr2+ into the lattice, the interatomic distance between Ba/Sr atoms and Eu2+ was expected to become shorter, resulting in a distortion of the inner EuOn polyhedrons. Then the crystal field strength surrounding Eu2+ was increased, finally resulting in the red shift.

  18. Ring Opening Metathesis Polymerization of Norbornene and Derivatives by the Triply Bonded Ditungsten Complex Na[W2(µ-Cl3Cl4(THF2]·(THF3

    Directory of Open Access Journals (Sweden)

    Georgios Floros

    2012-11-01

    Full Text Available In this study, the reactions of the bimetallic compound Na[W2(µ-Cl3Cl4(THF2]·(THF3 (1, (W 3 W6+, a'2e'4 with norbornene (NBE and some of its derivatives (5-X-2-NBE; X = COOH (NBE–COOH, OH (NBE–OH, CN (NBE–CN, COOMe (NBE–COOMe, CH=CH2 (VNBE; norbornadiene (NBD are described. Complex 1 contains a tungsten–tungsten triple bond, bearing three halide bridges and two labile THF ligands, in a cisoidal relationship along the metal–metal axis. The complex was found to be a highly efficient room temperature homogeneous and heterogeneous unicomponent initiator for the catalytic ring opening metathesis polymerization (ROMP of most substrates. NBE provides polynorbornene (PNBE of high molecular weight (Mw in high yields, soluble in organic solvents. The reaction proceeds with high cis-stereoselectivity (80%–86% cis, independently of the reaction conditions. Strongly coordinating pendant groups (–COOH, –OH, –CN deactivate 1, whereas substrates bearing softer ones (–COOMe, –CH=CH2 are quantitatively polymerized. NBD gives quantitatively insoluble PNBD. The polymers have been characterized by 1H, 13C NMR and Size Exclusion Chromatography (SEC. Monitoring the reactions in situ by 1H NMR (1/NBD or NBE provides direct evidence of the metathetical nature of the polymerization with the observation of the active tungsten alkylidene propagating polymeric chains. Mechanistic aspects of the reactions are discussed.

  19. Textural and mechanical characterization of C-S-H gels from hydration of synthetic T1-C{sub 3}S, {beta}-C{sub 2}S and their blends; Caracterizacion textural y mecanica de geles C-S-H formados en la hidratacion de muestras sinteticas T1-C{sub 3}S, {beta}-C{sub 2}S y sus mezclas

    Energy Technology Data Exchange (ETDEWEB)

    Goni, S.; Guerrero, A.; Puertas, F.; Hernandez, M. S.; Palacios, M.; Dolado, J. S.; Zhu, W.; Howind, T.

    2011-07-01

    The textural and mechanical characterization of C-S-H gels formed from the hydration of pure T1-C{sub 3}S, {beta}-C{sub 2}S and their blends are studied by Nitrogen sorption and nano indentation experiments. The surface area and nano porosity of C-S-H gels formed from the hydration of {beta}-C{sub 2}S and the 30-70 (T1-C{sub 3}S and {beta}-C{sub 2}S mixture) are higher than those from hydration of T1-C{sub 3}S, and 70-30, with the difference decreasing with hydration age. Such changes are well supported by findings of nano indentation study, which shows the greater relative volume of C-S-H phases with lower densities in the {beta}-C{sub 2}S and the 30-70 pastes. With the increase in hydration age, the relative volume of C-S-H phases with higher densities increased at the expenses of those with lower density. Important quantitative correlations were found among these textural characteristics and the mean chain length, determined from {sup 2}9Si magic-angle-spinning (MAS) NMR, of the C-S-H gels. (Author) 36 refs.

  20. Synthesis of (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolic acid, methyl (1'-/sup 13/C)olivetolate and (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolic acid

    Energy Technology Data Exchange (ETDEWEB)

    Porwoll, J.P.; Leete, E. (Minnesota Univ., Minneapolis (USA). Dept. of Chemistry)

    1985-03-01

    Potential advanced intermediates in the biosynthesis of delta/sup 9/-tetrahydrocannabinol, the major psychoactive principle of marijuana, have been synthesized labeled with two contiguous /sup 13/C atoms and /sup 14/C. Methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolate was prepared from lithium (/sup 13/C/sub 2/)acetylide and dimethyl (2-/sup 14/C)malonate. Reaction with geranyl bromide afforded methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolate, and hydrolysis of these methyl esters with lithium propyl mercaptide yielded the corresponding labeled acids. The /sup 13/C-/sup 13/C couplings observable in the /sup 13/C NMR spectra of these /sup 13/C-enriched compounds and their synthetic precursors are recorded. Methyl (1'-/sup 14/C)olivetolate was prepared from /sup 13/CO/sub 2/ to confirm assignments of the /sup 13/C chemical shifts in the pentyl side chain of these compounds.

  1. Synthesis, structural and optical properties of a novel bilayered organic-inorganic perovskite C{sub 5}Pb{sub 2}I{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Elleuch, S., E-mail: slimlpa@yahoo.f [Laboratoire de Physique Appliquee, Faculte des Sciences de Sfax, 3000, BP 1171, Sfax (Tunisia); Dammak, T.; Abid, Y. [Laboratoire de Physique Appliquee, Faculte des Sciences de Sfax, 3000, BP 1171, Sfax (Tunisia); Mlayah, A. [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CNRS-Universite Paul Sabatier, 29 Rue Jeanne Marvig, Toulouse 31055 (France); Boughzala, H. [Laboratoire de Materiaux et Cristallochimie, Institut Preparatoire aux etudes Ingenieur de Nabeul, 8000 Mrezga, Nabeul (Tunisia)

    2010-04-15

    Single crystals of [C{sub 5}H{sub 11}NH{sub 3}]Pb{sub 2}I{sub 5}, abbreviated C{sub 5}Pb{sub 2}I{sub 5}, have been prepared. This compound is a new member of the family of the bilayered organic-inorganic lead-iodide based perovskites. Its crystal structure has been determined by X-ray diffraction. The inorganic sub-lattice consists of periodic bilayers of iodoplumbate octahedra. Each PbI{sub 6} octahedra exhibits both edge- and corner-sharing with adjacent octahedra. The vibrational properties of this compound have been studied by Raman scattering spectroscopy. Optical absorption, photoluminescence and diffuse reflectance measurements have been performed. The room-temperature bandgap and free exciton absorption bands are observed at 2.46 and 2.23 eV, respectively. The exciton binding energy is 230 meV which is the largest value ever reported till date for the bilayered PbI based perovskites. Calculations assuming Wannier-type quasi-two-dimensional excitons and taking into account the image potential of the exciton charges showed that nearly 64% of the exciton binding energy is due to the dielectric confinement effect.

  2. Influence of milling time on microstructure and magnetic properties of Fe{sub 80}P{sub 11}C{sub 9} alloy produced by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Taghvaei, A.H. [Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Ghajari, F., E-mail: fati.ghajari@gmail.com [Department of Materials Science and Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Markó, D. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Prashanth, K.G. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Additive manufacturing Center, Sandvik AB, 81181 Sandviken (Sweden)

    2015-12-01

    Fe{sub 80}P{sub 11}C{sub 9} alloy with amorphous/nanocrytalline microstructure has been synthesized by mechanical alloying of the elemental powders. The microstructure, thermal behavior and morphology of the produced powders have been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. The crystallite size, lattice strain and fraction of the amorphous phase have been calculated by Rietveld refinement method. The results indicate that the powders microstructure consists of α-Fe(P,C) nanocrystals with an average diameter of 9 nm±1 nm dispersed in the amorphous matrix after 90 h of milling. Moreover, the fraction of amorphous phase initially increases up to 90 h of milling and then decreases after 120 h of milling, as a result of mechanical crystallization and formation of Fe{sub 2}P phase. The magnetic measurements show that while the saturation magnetization decreases continuously with the milling time, the coercivity exhibits a complicated trend. The correlation between microstructural changes and magnetic properties has been discussed in detail. - Highlights: • Glass formation was investigated in Fe{sub 80}P{sub 11}C{sub 9} by mechanical alloying. • Structural parameters were calculated by Rietveld refinement method. • Milling first increased and then decreased the fraction of amorphous phase. • Magnetic properties were significantly changed upon milling.

  3. Fullerenol C{sub 60}(OH){sub 24} nanoparticles decrease relaxing effects of dimethyl sulfoxide on rat uterus spontaneous contraction

    Energy Technology Data Exchange (ETDEWEB)

    Slavic, Marija, E-mail: marija17@ibiss.bg.ac.rs [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia); Djordjevic, Aleksandar [University of Novi Sad, Department of Chemistry, Biochemistry and the Environment, Faculty of Sciences (Serbia); Radojicic, Ratko [University of Belgrade, Faculty of Biology (Serbia); Milovanovic, Slobodan [University of East Sarajevo, Department of Pharmacology, Faculty of Medicine at Foca (Bosnia and Herzegowina); Orescanin-Dusic, Zorana [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia); Rakocevic, Zlatko [University of Belgrade, Institute for Nuclear Sciences ' Vinca' (Serbia); Spasic, Mihajlo B.; Blagojevic, Dusko [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia)

    2013-05-15

    Dimethyl sulfoxide (DMSO) is a widely used solvent and cryoprotectant that can cause impaired blood flow, reduction in intracranial pressure, tissue edema, inflammatory reactions, inhibition of vascular smooth muscle cell migration and proliferation, processes which can lead to atherosclerosis of the coronary, peripheral and cerebral circulation. Although the adverse effects are rare when DMSO is administered in clinically established concentrations, there is no safe antagonist for an overdose. In this work, we treated isolated spontaneous and calcium-induced contractile active rat uteri (Wistar, virgo intacta), with DMSO and fullerenol C{sub 60}(OH){sub 24} nanoparticle (FNP) in DMSO. FNP is a water-soluble derivative of fullerene C{sub 60}. Its size is a 1.1 nm in diameter and is a very promising candidate for a drug carrier in nanomedicine. FNP also displays free radical scavenging activity. DMSO decreased both spontaneous and calcium-induced contractions. In contrast, FNP only decreased spontaneous contraction. FNP decreased copper-zinc superoxide dismutase activity and prevented the DMSO-induced increase in glutathione reductase activity. Atomic force microscopy detected that FNP aggregated with calcium ions. Our results indicate that FNP has properties that make it a good candidate to be a modulator of DMSO activity which could minimize side effects of the latter.

  4. The study of applicability of dithiocarbamate-coated fullerene C{sub 60} for preconcentration of palladium for graphite furnace atomic absorption spectrometric determination in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Lesniewska, Barbara A. [Institute of Chemistry, University of BiaIystok, Hurtowa 1, 15-399 BiaIystok (Poland); Godlewska, Iwona [Institute of Chemistry, University of BiaIystok, Hurtowa 1, 15-399 BiaIystok (Poland); GodlewskayIkiewicz, Beata [Institute of Chemistry, University of BiaIystok, Hurtowa 1, 15-399 BiaIystok (Poland)]. E-mail: bgodlew@uwb.edu.pl

    2005-03-31

    The present method comprises an off-line enrichment of Pd on the fullerene, C{sub 60}, coated with ammonium pyrrolidinedithiocarbamate (APDC), followed by the elution of formed Pd-chelate with ethanol and the subsequent determination of Pd from the eluate by graphite furnace atomic absorption spectrometry. By using fullerene loaded with 0.1% APDC, the analytical system is simplified as the sample can be directly preconcentrated on the column. The following parameters affecting the preconcentration of Pd on C{sub 60} were optimized: amount of ligand used for the coating of fullerene, sample pH, kind of eluent, sample and eluent flow rates, volume and number of fractions of eluent used. The sorption efficiency for Pd on coated fullerene was 99.2{+-}1.1%. The best elution efficiency for Pd from the column was obtained with 0.6 ml of ethanol at a flow rate of 0.2 ml min{sup -1}. The limit of detection was 0.044 ng ml{sup -1}. The effect of sample pretreatment procedure on the preconcentration of Pd by evaluated method is discussed. The content of Pd in road dust (179.2{+-}17.4 ng g{sup -1}) determined by proposed method was in agreement with the results obtained with a reference method. The low recovery of analyte (64%) was obtained for geological material CRM SARM-7 (platinum ore) due to the much higher concentration of interfering elements.

  5. Single impact erosion studies of Cr{sub 3}C{sub 2}-NiCr coating: the role of microstructure variation

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, S.; Hyland, M.; James, B. [Massey Univ., Auckland (New Zealand)

    2008-07-01

    Cr{sub 3}C{sub 2}-NiCr thermal spray coatings have been extensively applied to mitigate erosion in high temperature applications such as aircraft and power generation turbines. Much laboratory based erosion research has been conducted under ambient temperature and mild erosion conditions. However, little has been presented about the coating response under the high temperature, high velocity erosion conditions typically experienced in industrial applications. This work presents the mechanisms of high velocity erosion based on experiments conducted under realistic service conditions. Single impact studies were carried out on a range of Cr{sub 3}C{sub 2}-NiCr coatings to assess the variation in erosion mechanism with phase degradation and starting powder morphology. Comparisons were made between the coating response in the as-sprayed state and after long-term heat treatment to determine how the erosion response changes as a function of exposure time in-service. Erosion of the as-sprayed coatings was heavily influenced by splat boundary related mass loss mechanisms. This was accentuated by in-flight carbide dissolution in the coatings based on agglomerated/sintered powders. Heat treatment led to splat sintering and a transition in the erosion response towards more microstructural based erosion mechanisms. The variation in erosion response as a function of microstructural development with heat treatment and starting powder type is presented. (orig.)

  6. Temperature of thermal spikes in amorphous silicon nitride films produced by 1.11 MeV C{sub 60}{sup 3+} impacts

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, T.; Nakajima, K.; Suzuki, M. [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan); Narumi, K.; Saitoh, Y. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Matsuda, M.; Sataka, M. [Nuclear Science Research Institute, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Tsujimoto, M.; Isoda, S. [Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501 (Japan); Kimura, K., E-mail: kimura@kues.kyoto-u.ac.jp [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan)

    2015-07-01

    Gold nanoparticles with an average diameter of 3.6 nm were deposited on amorphous silicon nitride (a-SiN) films. These samples were irradiated with 1.11 MeV C{sub 60}{sup 3+} ions to a fluence of ∼5 × 10{sup 10} ions/cm{sup 2} and observed using transmission electron microscopy (TEM). The ion tracks were clearly seen as bright spots and the gold nanoparticles disappeared from a surface area with a diameter of ∼20 nm around each ion track. The disappeared nanoparticles were collected by a foil placed in front of the sample. Gold particles of circular shape with a diameter of several nm were observed on the collector foil using TEM, suggesting that the gold nanoparticles were emitted as liquid droplets from the a-SiN film upon impact of the C{sub 60} ion. In view of the previous molecular dynamics simulations (Anders et al., 2009), this indicates that the surface temperature rises above the melting point of gold in the region with a diameter of ∼20 nm around the ion impact position.

  7. Production of Al nanocomposite reinforced by Fe-Al intermetallic, Al{sub 4}C{sub 3} and nano-Al{sub 2}O{sub 3} particles using wet milling in toluene

    Energy Technology Data Exchange (ETDEWEB)

    Razavi-Tousi, S.S., E-mail: ser105@mail.usask.ca [Islamic Azad University, Shahrood Branch, Shahrood (Iran, Islamic Republic of); Yazdani-Rad, R. [Materials and Energy Research Center, P.O. Box 31787/316, Karaj (Iran, Islamic Republic of); Manafi, S.A. [Islamic Azad University, Shahrood Branch, Shahrood (Iran, Islamic Republic of)

    2011-06-02

    Highlights: > Production of Al nanocomposite reinforced by Fe-Al intermetallic, Al{sub 4}C{sub 3} and nano-Al{sub 2}O{sub 3} particles using wet milling in toluene. > Production of Al{sub 4}C{sub 3} particles from mechanochemical reaction of Al with PCA. > Effect of second phase particles on sintering. - Abstract: Al matrix nanocomposites were produced by wet milling of Al and nano-alumina powders in a toluene media. X-ray diffraction patterns, inductively coupled plasma, carbon measurement analysis and scanning electron microscopy show that impurities introduced by decomposition of toluene and abrasion of balls and vials are uniformly dispersed in the Al matrix as Al{sub 4}C{sub 3} and Fe-Al intermetallic particles. Though producing homogenous nanocomposites, these second phase particles seem to have a retarding effect on densification of nanocomposite powders.

  8. Thermodynamic Properties of Magnesium Chloride Hydroxide Hydrate (Mg3Cl(OH)5:4H2O, Phase 5), and Its importance to Nuclear Waste Isolation in Geological Repositories in Salt Formations

    Science.gov (United States)

    Xiong, Y.; Deng, H.; Nemer, M. B.; Johnsen, S.

    2009-12-01

    MgO (bulk, pure MgO corresponding to the mineral periclase) is the only engineered barrier certified by the Environmental Protection Agency for emplacement in the Waste Isolation Pilot Plant (WIPP) in the US, and an Mg(OH)2-based engineered barrier (bulk, pure Mg(OH)2 corresponding to brucite) is to be employed in the Asse repository in Germany. Both the WIPP and the Asse are located in salt formations. The WIPP is a U.S. Department of Energy geological repository being used for the permanent disposal of defense-related transuranic waste (TRU waste). The repository is 655 m below the surface, and is situated in the Salado Formation, a Permian salt bed mainly composed of halite, and of lesser amounts of polyhalite, anhydrite, gypsum, magnesite, clays and quartz. The WIPP Generic Weep Brine (GWB), a Na-Mg-Cl dominated brine, is associated with the Salado Formation. The previous vendor for MgO for the WIPP was Premier Chemicals and the current vendor is Martin Marietta Materials. Experimental studies of both Premier MgO and Martin Marietta MgO with the GWB at SNL indicate the formation of magnesium chloride hydroxide hydrate, Mg3Cl(OH)5:4H2O, termed as phase 5. However, this important phase is lacking in the existing thermodynamic database. In this study, the solubility constant of phase 5 is determined from a series of solubility experiments in MgCl2-NaCl solutions. The solubility constant at 25 oC for the following reaction, Mg3Cl(OH)5:4H2O + 5H+ = 3Mg2+ + 9H2O(l) + Cl- is recommended as 43.21±0.33 (2σ) based on the Specific Interaction Theory (SIT) model for extrapolation to infinite dilution. The log K obtained via the Pitzer equations is identical to the above value within the quoted uncertainty. The Gibbs free energy and enthalpy of formation for phase 5 at 25 oC are derived as -3384±2 (2σ) kJ mol-1 and -3896±6 (2σ) kJ mol-1, respectively. The standard entropy and heat capacity of phase 5 at 25 oC are estimated as 393±20 J mol-1 K-1 and 374±19 J mol-1 K

  9. Effects of the temperature and beam parameters on depth profiles in X-ray photoelectron spectrometry and secondary ion mass spectrometry under C{sub 60}{sup +}–Ar{sup +} cosputtering

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Hua-Yang [Research Center for Applied Science, Academia Sinica, Taipei 115, Taiwan (China); Tsai, Meng-Hung [Department of Materials Science and Engineering, Nation Taiwan University, Taipei 106, Taiwan (China); Kao, Wei-Lun; Kuo, Ding-Yuan [Research Center for Applied Science, Academia Sinica, Taipei 115, Taiwan (China); Shyue, Jing-Jong, E-mail: shyue@gate.sinica.edu.tw [Research Center for Applied Science, Academia Sinica, Taipei 115, Taiwan (China); Department of Materials Science and Engineering, Nation Taiwan University, Taipei 106, Taiwan (China)

    2014-12-10

    Highlights: • XPS and SIMS depth profiles of PMMA were acquired concurrently with C{sub 60}{sup +}–Ar{sup +} cosputtering. • Artificial signal enhancement at the interface was observed in SIMS when using C{sub 60}{sup +} sputtering. • Optimized cosputtering yielded higher SIMS intensities and removed the artificial enhancement. • Increasing or decreasing the temperature further improved the resulting depth profile. - Abstract: Polymethylmethacrylate (PMMA) is widely used in various fields, including the semiconductor, biomaterial and microelectronic fields. Obtaining the correct depth profiles of PMMA is essential, especially when it is used as a thin-film. There have been many studies that have used earlier generation of cluster ion (SF{sub 5}{sup +}) as the sputtering source to profile PMMA films, but few reports have discussed the use of the more recently developed C{sub 60}{sup +} in the PMMA sputtering process. In this study, X-ray photoelectron spectroscopy (XPS) and dynamic secondary ion mass spectroscopy (D-SIMS) were used concurrently to monitor the depth profiles of PMMA under C{sub 60}{sup +} bombardment. Additionally, the cosputtering technique (C{sub 60}{sup +} sputtering with auxiliary, low-kinetic-energy Ar{sup +}) was introduced to improve the analytical results. The proper cosputtering conditions could eliminate the signal enhancement near the interface that occurred with C{sub 60}{sup +} sputtering and enhance the sputtering yield of the characteristic signals. Atomic force microscopy (AFM) was also used to measure the ion-induced topography. Furthermore, the effect of the specimen temperature on the PMMA depth profile was also examined. At higher temperatures (+120 °C), the depolymerization reaction that corresponded to main-chain scission dominated the sputtering process. At lower temperatures (−120 °C), the cross-linking mechanism was retarded significantly due to the immobilization of free radicals. Both the higher and lower

  10. Reactions between atomic chlorine and pyridine in solid para-hydrogen: Infrared spectrum of the 1-chloropyridinyl (C{sub 5}H{sub 5}N-Cl) radical

    Energy Technology Data Exchange (ETDEWEB)

    Das, Prasanta; Bahou, Mohammed [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Lee, Yuan-Pern [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China)

    2013-02-07

    With infrared absorption spectra we investigated the reaction between Cl atom and pyridine (C{sub 5}H{sub 5}N) in a para-hydrogen (p-H{sub 2}) matrix. Pyridine and Cl{sub 2} were co-deposited with p-H{sub 2} at 3.2 K; a planar C{sub 5}H{sub 5}N-Cl{sub 2} complex was identified from the observed infrared spectrum of the Cl{sub 2}/C{sub 5}H{sub 5}N/p-H{sub 2} matrix. Upon irradiation at 365 nm to generate Cl atom in situ and annealing at 5.1 K for 3 min to induce secondary reaction, the 1-chloropyridinyl radical (C{sub 5}H{sub 5}N-Cl) was identified as the major product of the reaction Cl + C{sub 5}H{sub 5}N in solid p-H{sub 2}; absorption lines at 3075.9, 1449.7, 1200.6, 1148.8, 1069.3, 1017.4, 742.9, and 688.7 cm{sup -1} were observed. The assignments are based on comparison of observed vibrational wavenumbers and relative IR intensities with those predicted using the B3PW91/6-311++G(2d, 2p) method. The observation of the preferential addition of Cl to the N-site of pyridine to form C{sub 5}H{sub 5}N-Cl radical but not 2-, 3-, or 4-chloropyridine (ClC{sub 5}H{sub 5}N) radicals is consistent with the reported theoretical prediction that formation of the former proceeds via a barrierless path.

  11. Ru(CO)3Cl(Glycinate) (CORM-3): A Carbon Monoxide–Releasing Molecule with Broad-Spectrum Antimicrobial and Photosensitive Activities Against Respiration and Cation Transport in Escherichia coli

    Science.gov (United States)

    Wilson, Jayne Louise; Jesse, Helen E.; Hughes, Bethan; Lund, Victoria; Naylor, Kathryn; Davidge, Kelly S.; Cook, Gregory M.; Mann, Brian E.

    2013-01-01

    Abstract Aims: Carbon monoxide (CO) delivered to cells and tissues by CO-releasing molecules (CO-RMs) has beneficial and toxic effects not mimicked by CO gas. The metal carbonyl Ru(CO)3Cl(glycinate) (CORM-3) is a novel, potent antimicrobial agent. Here, we established its mode of action. Results: CORM-3 inhibits respiration in several bacterial and yeast pathogens. In anoxic Escherichia coli suspensions, CORM-3 first stimulates, then inhibits respiration, but much higher concentrations of CORM-3 than of a classic protonophore are required for stimulation. Proton translocation measurements (H+/O quotients, i.e., H+ extrusion on pulsing anaerobic cells with O2) show that respiratory stimulation cannot be attributed to true “uncoupling,” that is, dissipation of the protonmotive force, or to direct stimulation of oxidase activity. Our data are consistent with CORM-3 facilitating the electrogenic transmembrane movement of K+ (or Na+), causing a stimulation of respiration and H+ pumping to compensate for the transient drop in membrane potential (ΔΨ). The effects on respiration are not mimicked by CO gas or control Ru compounds that do not release CO. Inhibition of respiration and loss of bacterial viability elicited by CORM-3 are reversible by white light, unambiguously identifying heme-containing oxidase(s) as target(s). Innovation: This is the most complete study to date of the antimicrobial action of a CO-RM. Noteworthy are the demonstration of respiratory stimulation, electrogenic ion transport, and photosensitive activity, establishing terminal oxidases and ion transport as primary targets. Conclusion: CORM-3 has multifaceted effects: increased membrane permeability, inhibition of terminal oxidases, and perhaps other unidentified mechanisms underlie its effectiveness in tackling microbial pathogenesis. Antioxid. Redox Signal. 19, 497–509. PMID:23186316

  12. Interaction of the carbon monoxide-releasing molecule Ru(CO)3Cl(glycinate) (CORM-3) with Salmonella enterica serovar Typhimurium: in situ measurements of carbon monoxide binding by integrating cavity dual-beam spectrophotometry.

    Science.gov (United States)

    Rana, Namrata; McLean, Samantha; Mann, Brian E; Poole, Robert K

    2014-12-01

    Carbon monoxide (CO) is a toxic gas that binds to haems, but also plays critical signalling and cytoprotective roles in mammalian systems; despite problems associated with systemic delivery by inhalation of the gas, it may be employed therapeutically. CO delivered to cells and tissues by CO-releasing molecules (CO-RMs) has beneficial and toxic effects not mimicked by CO gas; CO-RMs are also attractive candidates as novel antimicrobial agents. Salmonella enterica serovar Typhimurium is an enteropathogen causing gastroenteritis in humans. Recent studies have implicated haem oxygenase-1 (HO-1), the protein that catalyses the degradation of haem into biliverdin, free iron and CO, in the host immune response to Salmonella infection. In several studies, CO administration via CO-RMs elicited many of the protective roles of HO-1 induction and so we investigated the effects of a well-characterized water-soluble CO-RM, Ru(CO)3Cl(glycinate) (CORM-3), on Salmonella. CORM-3 exhibits toxic effects at concentrations significantly lower than those reported to cause toxicity to RAW 264.7 macrophages. We demonstrated here, through oxyhaemoglobin assays, that CORM-3 did not release CO spontaneously in phosphate buffer, buffered minimal medium or very rich medium. CORM-3 was, however, accumulated to high levels intracellularly (as shown by inductively coupled plasma MS) and released CO inside cells. Using growing Salmonella cultures without prior concentration, we showed for the first time that sensitive dual-beam integrating cavity absorption spectrophotometry can detect directly the CO released from CORM-3 binding in real-time to haems of the bacterial electron transport chain. The toxic effects of CO-RMs suggested potential applications as adjuvants to antibiotics in antimicrobial therapy.

  13. [Ph(3)PCH(2)Ph](2)[Zn(3)(tp)(3)Cl(2)] and Ni(3)(tma)(2)(H(2)O)(8): two unusual claylike frameworks of metal-polycarboxylate coordination polymers (tp = terephthalate, tma = trimesate).

    Science.gov (United States)

    Yang, Guo-Dong; Dai, Jing-Cao; Lian, Yun-Xia; Wu, Wen-Shi; Lin, Jian-Ming; Hu, Sheng-Min; Sheng, Tian-Lu; Fu, Zhi-Yong; Wu, Xin-Tao

    2007-09-17

    Two new compounds, [Ph3PCH2Ph]2[Zn3(tp)3Cl2] (1) and Ni3(tma)2(H2O)8 (2) (tp = terephthalate, tma = trimesate), are metal-polycarboxylate coordination polymers prepared by similar hydrothermal synthesis techniques. X-ray single-crystal structural analysis shows that both compounds crystallize in the 2D claylike lamellar architectures, in which 1 possesses the interlayer [Ph3PCH2Ph]+ exchangeable cation and has been confirmed by PXRD patterns. 1 (C74H56Cl2O12P2Zn3) belongs to monoclinic P21/c, Z = 2 (a = 18.956(1) A, b = 10.2697(5) A, c = 17.067(1) A, beta = 99.486(4) degrees ). 2 (C18H22O20Ni3) is attributed to triclinic P, Z = 1 (a = 6.6643(8) A, b = 9.622(1) A, c = 10.089(1) A, alpha = 112.675(2) degrees , beta = 94.007(1) degrees, gamma = 106.411(2) degrees ). Linear metal trinuclear clusters bridged by rigid linear tp ligands for 1 and trigonal tma ligands for 2 give rise to a novel 2D 6-linked (3,6) topological anionic network in 1 and an interesting 2D 3,6-linked molybdenite topological neutral network in 2, respectively. Both compounds exhibit intense fluorescent emission bands at 410 nm (lambda(exc) = 355 nm) for 1 and 398 nm (lambda(exc) = 300 nm) for 2 in the solid state at room temperature.

  14. Synthesis and crystal structure of a new homoleptic tetraarylruthenium(IV) complex Ru(2,4,5-Me{sub 3}C{sub 6}H{sub 2}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chang-Jiu; Wu, Xiu-Li; Ma, Xiu-Fang; Jia, Ai-Quan; Zhang, Qian-Feng [Anhui Univ. of Technology, Anhui (China). Inst. of Molecular Engineering and Applied Chemistry and Anhui Province Key Lab. of Metallurgy Engineering and Resources Recycling

    2017-08-01

    Treatment of [Ru(acac){sub 3}] (acac-=acetylacetonate) with (2,4,5-Me{sub 3}C{sub 6}H{sub 2})MgBr, followed by column chromatography in air, afforded the homoleptic tetraaryl-ruthenium(IV) complex [Ru(2,4,5-Me{sub 3}C{sub 6}H{sub 2}){sub 4}] (1) in moderate yield. The product was characterized by proton NMR spectroscopy and microanalyses. Its crystal structure has also been established by X-ray crystallography.

  15. Structural phase transition causing anomalous photoluminescence behavior in perovskite (C{sub 6}H{sub 11}NH{sub 3}){sub 2}[PbI{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Yangui, A. [Groupe d’Etudes de la Matière Condensée, UMR CNRS 8653-Université de Versailles Saint Quentin En Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles (France); Laboratoire de Physique Appliquée, Faculté des Sciences de Sfax, Route de Soukra km 3.5 BP 1171, 3018 Sfax (Tunisia); Pillet, S. [Laboratoire de Cristallographie, Résonance Magnétique et Modélisations, UMR-CNRS 7036, Institut Jean Barriol, Université de Lorraine, BP 239, 54506 Vandoeuvre-lès-Nancy (France); Mlayah, A. [Centre d’Elaboration de Matériaux et d’Etudes Structurales (CEMES), CNRS UPR 8011-Université de Toulouse, 29 rue Jeanne Marvig 31055, Toulouse, Cedex 4 (France); Lusson, A.; Bouchez, G.; Boukheddaden, K., E-mail: Younes.abid@fss.rnu.tn, E-mail: kbo@physique.uvsq.fr [Groupe d’Etudes de la Matière Condensée, UMR CNRS 8653-Université de Versailles Saint Quentin En Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles (France); Triki, S. [Laboratoire de Chimie, Electrochimie Moléculaires, Chimie Analytique, UMR CNRS 6521-Université de Bretagne Occidentale, BP 809, 29285 Brest (France); Abid, Y., E-mail: Younes.abid@fss.rnu.tn, E-mail: kbo@physique.uvsq.fr [Laboratoire de Physique Appliquée, Faculté des Sciences de Sfax, Route de Soukra km 3.5 BP 1171, 3018 Sfax (Tunisia)

    2015-12-14

    Optical and structural properties of the organic-inorganic hybrid perovskite-type (C{sub 6}H{sub 11}NH{sub 3}){sub 2}[PbI{sub 4}] (abbreviated as C{sub 6}PbI{sub 4}) were investigated using optical absorption, photoluminescence (PL), and x-ray diffraction measurements. Room temperature, optical absorption measurements, performed on spin-coated films of C{sub 6}PbI{sub 4}, revealed two absorption bands at 2.44 and 3.21 eV. Upon 325 nm (3.815 eV) laser irradiation, strong green PL emission peaks were observed at 2.41 eV (P1) and 2.24 eV (P2) and assigned to free and localized excitons, respectively. The exciton binding energy was estimated at 356 meV. At low temperature, two additional emission bands were detected at 2.366 eV (P3) and a large band (LB) at 1.97 eV. The former appeared only below 40 K and the latter emerged below 130 K. The thermal dependence of the PL spectra revealed an abnormal behavior accompanied by singularities in the peak positions and intensities at 40 and 130 K. X-ray diffraction studies performed on powder and single crystals as a function of temperature evidenced significant changes of the interlayer spacing at 50 K and ∼138 K. Around 138 K, a commensurate to incommensurate structural phase transition occurred on cooling. It involves a symmetry breaking leading to a distortion of the PbI{sub 6} octahedron. The resulting incommensurate spatial modulation of the Pb–I distances (and Pb–I–Pb angles) causes a spatial modulation of the band gap, which is at the origin of the emergence of the LB below ∼130 K and the anomalous behavior of the position of P1 below 130 K. The change of the interlayer spacing in the 40-50 K range may in turn be related to the significant decrease of the intensity of P2 and the maximum emission of the LB. These results underline the intricate character of the structural and the PL properties of the hybrid perovskites; understanding such properties should benefit to the design of optoelectronic devices with

  16. The coloring problem in the solid-state metal boride carbide ScB{sub 2}C{sub 2}. A theoretical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lassoued, Souheila [Universite de Rennes, Ecole Nationale Superieure de Chimie, UMR 6226 CNRS (France). Inst. des Sciences Chimiques; Universite Kasdi Merbah-Ouargla (Algeria). Faculte des Mathematiques et des Sciences de la Matiere; Boucher, Benoit [Universite de Rennes, Ecole Nationale Superieure de Chimie, UMR 6226 CNRS (France). Inst. des Sciences Chimiques; Max-Planck-Institut fuer Chemische Physik Fester Stoffe, Dresden (Germany); Boutarfaia, Ahmed [Universite Kasdi Merbah-Ouargla (Algeria). Faculte des Mathematiques et des Sciences de la Matiere; Gautier, Regis; Halet, Jean-Francois [Universite de Rennes, Ecole Nationale Superieure de Chimie, UMR 6226 CNRS (France). Inst. des Sciences Chimiques

    2016-08-01

    The electronic properties of the layered ternary metal boride carbide ScB{sub 2}C{sub 2}, the structure of which consists of B/C layers made of fused five- and seven-membered rings alternating with scandium sheets, are analyzed. In particular, the respective positions of the B and C atoms (the so-called coloring problem) are tackled using density functional theory, quantum theory of atoms in molecules, and electron localizability indicator calculations. Results reveal that (i) the most stable coloring minimizes the number of B-B and C-C contacts and maximizes the number of boron atoms in the heptagons, (ii) the compound is metallic in character, and (iii) rather important covalent bonding occurs between the metallic sheets and the boron-carbon network.

  17. Synthesis and characterization of binder-free Cr{sub 3}C{sub 2} coatings on nickel-based alloys for molten fluoride salt corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Brupbacher, Michael C.; Zhang, Dajie [Department of Materials Science and Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Buchta, William M. [The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Graybeal, Mark L. [U.S. Army Research Laboratory, Aberdeen Proving Ground, MD 21005 (United States); Rhim, Yo-Rhin [The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Nagle, Dennis C. [Department of Materials Science and Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Spicer, James B., E-mail: spicer@jhu.edu [Department of Materials Science and Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

    2015-06-15

    Under various conditions, chromium carbides appear to be relatively stable in the presence of molten fluoride salts and this suggests that their use in corrosion resistant coatings for fluoride salt environments could be beneficial. One method for producing these coatings is the carburization of sprayed Cr coatings using methane-containing gaseous precursors. This process has been investigated for the synthesis of binder-free chromium carbide coatings on nickel-based alloy substrates for molten fluoride salt corrosion resistance. The effects of the carburization process on coating microstructure have been characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) in conjunction with energy dispersive spectroscopy (EDS). Both plasma-sprayed and cold-sprayed Cr coatings have been successfully converted to Cr{sub 3}C{sub 2}, with the mechanism of conversion being strongly influenced by the initial porosity in the as-deposited coatings.

  18. Preparative separation of C{sub 19}-diterpenoid alkaloids from Aconitum carmichaelii Debx by pH zone-refining counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dahui [Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming (China); Shu, Xikai; Wang, Xiao; Fang, Lei; Huang, Luqi, E-mail: wxjn1998@126.com [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China); Xi, Xingjun; Zheng, Zhenjia [China National institute of Standardization, Beijing (China)

    2013-11-01

    The technique of pH-zone-refining counter-current chromatography was successfully applied to preparatively separate three C{sub 19}-diterpenoid alkaloids from the crude extracts of Aconitum carmichaelii for the first time using a two-phase solvent system of petroleum ether-ethyl acetate-methanol-water (5:5:1:9, v/v/v/v). Mesaconitine (I), hypaconitine (II), and deoxyaconitine (III) were obtained from 2.5 g of the crude alkaloids in a one-step separation; the yields were 4.16%, 16.96%, and 5.05%, respectively. The purities of compounds I, II, and III were 93.0%, 95%, and 96%, respectively, as determined by HPLC. The chemical structures of the three compounds were identified by electrospray ionization mass spectrometry (ESI-MS) and NMR. (author)

  19. Anomaly in the electric resistivity of one-dimensional uneven peanut-shaped C{sub 60} polymer film at a low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ryuzaki, Soh; Onoe, Jun, E-mail: jonoe@nr.titech.ac.jp [Research Laboratory for Nuclear Reactors and Department of Nuclear Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8550 (Japan)

    2014-03-17

    We performed in situ four-probe measurements of the current-voltage characteristics of one-dimensional (1D) uneven peanut-shaped C{sub 60} polymer films in the temperature range 30–350 K under ultrahigh vacuum conditions (2 × 10{sup −7} Pa). Arrhenius plots of the film resistance with respect to temperature showed two different electron-conduction mechanisms. While electrons are conducted via a thermal excitation hopping at temperatures above 160 K, the resistivity of the 1D polymer film exhibits an anomalous behavior that becomes fluctuated at a given value in the temperature range 40–90 K and decreases at temperatures below 40 K.

  20. Sputtering of SiN films by 540 keV C{sub 60}{sup 2+} ions observed using high-resolution Rutherford backscattering spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, K.; Morita, Y.; Kitayama, T.; Suzuki, M. [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan); Narumi, K.; Saitoh, Y. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gumma 370-1292 (Japan); Tsujimoto, M.; Isoda, S. [Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501 (Japan); Fujii, Y. [Center for Supports to Research and Education Activities, Kobe University, Kobe 657-8501 (Japan); Kimura, K., E-mail: kimura@kues.kyoto-u.ac.jp [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan)

    2014-08-01

    Amorphous silicon nitride films deposited on Si(0 0 1) were irradiated with 540 keV C{sub 60} ions to fluences ranging from 2.5 × 10{sup 11} to 1 × 10{sup 14} ions/cm{sup 2}. The composition depth profiles of the irradiated samples were measured using high-resolution Rutherford backscattering spectroscopy. Both silicon and nitrogen in the film decrease rapidly with fluence. From the observed result the sputtering yields are obtained as 3900 ± 500 N atoms/ion and 1500 ± 1000 Si atoms/ion. Such large sputtering yield cannot be explained by either the elastic sputtering or the electronic sputtering, indicating that the synergy effect between the elastic sputtering and the electronic sputtering plays an important role.

  1. Estudio comparativo de las moléculas isovalentes de interés atmosférico CF3Cl y CF3Br y sus correspondientes halógenos aislados Cl y Br.

    Science.gov (United States)

    Mayor, E.; Velasco, A. M.; Martín, I.; Lavín, C.

    Los estados Rydberg moleculares han suscitado en los últimos años un creciente interés entre los espectroscopistas experimentales, motivado en parte por el desarrollo de nuevas técnicas espectroscópicas capaces de investigar estos estados altamente excitados electrónicamente. Los procesos de fotoabsorción que implican estados Rydberg en los derivados halogenados del metano son de gran importancia, debido a su abundancia en la atmósfera y a sus implicaciones medioambientales. Por ello, la obtención de datos relativos a sus fuerzas de oscilador es de gran interés. En este trabajo se aborda el estudio de dichas propiedades para las moléculas isovalentes CF3Cl y CF3Br. Ambas moléculas presentan idéntica estructura electrónica para el estado fundamental por lo que se espera que sus espectros Rydberg presenten grandes similitudes, en ausencia de perturbaciones. Por ello y dada la escasez de datos relativos a fuerzas de oscilador, hemos establecido la corrección de nuestros resultados en base a las analogías esperadas en las intensidades espectrales correspondientes a transiciones análogas. Por otro lado, Novak y col. [1] han encontrado experimentalmente un marcado carácter atómico en el espectro correspondiente a estas moléculas, siendo muy similar a los de los átomos de Cl y Br. Por ello en el presente trabajo, además de establecer la comparación entre ambas moléculas hemos buscado las similitudes con sus respectivos halógenos. Los cálculos relativos a las especies moleculares se han realizado utilizando la Metodología Molécular de Orbítales de Defecto Cuántico (MQDO) [2], mientras que para el estudio de los átomos de Cl y Br se empleó la versión relativista del método (RQDO) [3].

  2. Copper-impregnated Al-Ce-pillared clay for selective catalytic reduction of NO by C{sub 3}H{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Qichun; Hao, Jiming; Li, Junhua [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Ma, Zifeng [Department of Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Lin, Weiming [Department of Chemical Engineering, Guangzhou University, Guangzhou 510405 (China)

    2007-08-30

    The selective catalytic reduction (SCR) of NO by hydrocarbon is an efficient way to remove NO emission from lean-burn gasoline and diesel exhaust. In this paper, a thermally and hydrothermally stable Al-Ce-pillared clay (Al-Ce-PILC) was synthesized and then modified by SO{sub 4}{sup 2-}, whose surface area and average pore diameter calcined at 773 K were 161 m{sup 2}/g and 12.15 nm, respectively. Copper-impregnated Al-Ce-pillared clay catalyst (Cu/SO{sub 4}{sup 2-}/Al-Ce-PILC) was applied for the SCR of NO by C{sub 3}H{sub 6} in the presence of oxygen. The catalyst 2 wt% Cu/SO{sub 4}{sup 2-}/Al-Ce-PILC showed good performance over a broad range of temperature, its maximum conversion of NO was 56% at 623 K and remained as high as 22% at 973 K. Furthermore, the presence of 10% water slightly decreased its activity, and this effect was reversible following the removal of water from the feed. Py-IR results showed SO{sub 4}{sup 2-} modification greatly enhanced the number and strength of Broensted acidity on the surface of Cu/SO{sub 4}{sup 2-}/Al-Ce-PILC, which played a vital role in the improvement of NO conversion. TPR and XPS results indicated that both Cu{sup +} and isolated Cu{sup 2+} species existed on the optimal catalyst, mainly Cu{sup +}, as Cu content increased to 5 wt%, another species CuO aggregates which facilitated the combustion of C{sub 3}H{sub 6} were formed. (author)

  3. Synthesis, single-crystal structure determination and Raman spectra of the tricyanomelaminates NaA{sub 5}[C{sub 6}N{sub 9}]{sub 2} . 4 H{sub 2}O (A = Rb, Cs)

    Energy Technology Data Exchange (ETDEWEB)

    Reckeweg, Olaf; DiSalvo, Francis J. [Cornell Univ., Ithaca, NY (United States). Baker Lab.; Schulz, Armin [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2016-07-01

    Transparent colorless crystals of NaA{sub 5}[C{sub 6}N{sub 9}]{sub 2} . 4 H{sub 2}O (A = Rb, Cs) were obtained by blending aqueous solutions of Na{sub 3}[C{sub 6}N{sub 9}] and RbF or CsF, respectively, and subsequent evaporation of the water under ambient conditions. Both compounds crystallize in the space group P2{sub 1}/m (no. 11) with the cell parameters a = 815.56(16), b = 1637.7(4) and c = 1036.4(3) pm, and β = 110.738(12) for NaRb{sub 5}[C{sub 6}N{sub 9}]{sub 2} . 4 H{sub 2}O and a = 843.32(6), b = 1708.47(11) and c = 1052.42(7) pm, and β = 112.034(2) for NaCs{sub 5}[C{sub 6}N{sub 9}]{sub 2} . 4 H{sub 2}O, respectively. Raman spectra of the title compounds complement our results.

  4. Determination and modelling of osmotic coefficients and vapour pressures of binary systems 1- and 2-propanol with C{sub n}MimNTf{sub 2} ionic liquids (n = 2, 3, and 4) at T = 323.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Calvar, Noelia [LSRE - Laboratory of Separation and Reaction Engineering, Associate Laboratory, LSRE/LCM, Department of Chemical Engineering, Faculty of Engineering, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal); Gomez, Elena; Dominguez, Angeles [Advanced Separation Processes Group, Department of Chemical Engineering, University of Vigo, 36310 Vigo (Spain); Macedo, Eugenia A., E-mail: eamacedo@fe.up.pt [LSRE - Laboratory of Separation and Reaction Engineering, Associate Laboratory, LSRE/LCM, Department of Chemical Engineering, Faculty of Engineering, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal)

    2011-08-15

    Highlights: > Osmotic coefficients of 1- and 2-propanol with C{sub n}MimNTf{sub 2} (n = 2, 3, and 4) are determined. > Experimental data were correlated with extended Pitzer model of Archer and MNRTL. > Mean molal activity coefficients and excess Gibbs free energies were calculated. > Effect of the anion is studied comparing these results with literature. - Abstract: The osmotic and activity coefficients and vapour pressures of binary mixtures containing 1-propanol, or 2-propanol and imidazolium-based ionic liquids with bis(trifluoromethylsulfonyl)imide as anion (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 2}MimNTf{sub 2}, 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 3}MimNTf{sub 2}, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 4}MimNTf{sub 2}) were determined at T = 323.15 K using the vapour pressure osmometry technique. The experimental osmotic coefficients were correlated using the extended Pitzer model modified by Archer and the MNRTL model, obtaining standard deviations lower than 0.033 and 0.064, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the mixtures studied were calculated from the parameters of the extended Pitzer model modified by Archer. Besides the effect of the alkyl-chain of the cation, the effect of the anion can be assessed comparing the experimental results with those previously obtained for imidazolium ionic liquids with sulphate anions.

  5. XPS analysis of nanocomposite Li{sub 2x−y}Mn{sub 1−x}PS{sub 3}(C{sub 13}H{sub 11}N{sub 2}){sub y} films

    Energy Technology Data Exchange (ETDEWEB)

    Silipigni, L., E-mail: lsilipigni@unime.it [Dipartimento di Fisica e di Scienze della Terra, Università di Messina, V.le F.Stagno d’Alcontres 31, I-98166 Messina (Italy); Schirò, L., E-mail: lschiro@unime.it [Dipartimento di Fisica e di Scienze della Terra, Università di Messina, V.le F.Stagno d’Alcontres 31, I-98166 Messina (Italy); Scolaro, L. Monsù, E-mail: lmonsu@unime.it [Dipartimento di Scienze Chimiche, Università di Messina, Salita Sperone 31, I-98166 Messina (Italy); De Luca, G., E-mail: delucag@unime.it [Dipartimento di Scienze del Farmaco e Prodotti per la Salute, V.le Annunziata, I-98168 Messina (Italy); Salvato, G., E-mail: salvato@me.cnr.it [CNR-IPCF Istituto per i Processi Chimico-Fisici, V.le F. Stagno d’Alcontres 37, I-98158 Messina (Italy)

    2013-09-01

    Intercalation of 9-aminoacridine (9AA: C{sub 13}H{sub 10}N{sub 2}) in thin films of exfoliated Li{sub 2x−y}Mn{sub 1−x}PS{sub 3} has been performed by means of a solution approach starting from the hydrochloride salt of the organic species (9AAHCl: C{sub 13}H{sub 10}N{sub 2}·HCl). The resulting nanocomposite Li{sub 2x−y}Mn{sub 1−x}PS{sub 3}(C{sub 13}H{sub 11}N{sub 2}){sub y} films have been investigated by X-ray photoemission spectroscopy (XPS), at room temperature, in the regions of the Mn, P, S and Cl 2p, Li, C and N 1s and Mn 3p core levels. The XPS analysis has been also carried out on the 9-aminoacridine hydrochloride films whose XPS spectra have been compared with those of the Li{sub 2x−y}Mn{sub 1−x}PS{sub 3}(C{sub 13}H{sub 11}N{sub 2}){sub y} films to obtain information about the nature of the interaction between the guest species (9AAH{sup +}) and the matrix (Li{sub 2x−y}Mn{sub 1−x}PS{sub 3}{sup −}).

  6. Synthesis, characterization and standard molar enthalpy of formation of La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO)

    Energy Technology Data Exchange (ETDEWEB)

    Li Qiangguo [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China)]. E-mail: liqiangguo@163.com; Li Xu [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Huang Yi [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Xiao Shengxiong [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Yang Dejun [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Ye Lijuan [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Wei Deliang [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Liu Yi [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); College of Chemistry and Molecular Science, Wuhan University, Wuhan 430062 (China)

    2006-02-15

    The product from reaction of lanthanum chloride seven-hydrate with salicylic acid and 8-hydroxyquinoline, La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO), was characterized by IR, elemental analysis, molar conductance, and thermogravimetric analysis. The standard molar enthalpies of solution of [LaCl{sub 3}.7H{sub 2}O (s)], [2C{sub 7}H{sub 6}O{sub 3} (s)], [C{sub 9}H{sub 7}NO (s)] and [La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO) (s)] in a mixed solvent of absolute ethyl alcohol, dimethyl formamide (DMF) and perchloric acid were determined by calorimetry to be {delta}{sub s}H{sub m}{sup {theta}}[LaCl{sub 3}.7H{sub 2}O (s), 298.15K]=-96.45+/-0.18kJmol{sup -1}, {delta}{sub s}H{sub m}{sup {theta}}[2C{sub 7}H{sub 6}O{sub 3} (s), 298.15K]=14.99+/-0.17kJmol{sup -1}, {delta}{sub s}H{sub m}{sup {theta}}[C{sub 9}H{sub 7}NO (s), 298.15K]=-3.86+/-0.06kJmol{sup -1} and {delta}{sub s}H{sub m}{sup {theta}}[La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO) (s), 298.15K]=-117.78+/-0.11kJmol{sup -1}. The enthalpy change of the reaction(1)LaCl{sub 3}.7H{sub 2}O(s)+2C{sub 7}H{sub 6}O{sub 3}(s)+C{sub 9}H{sub 7}NO(s)=La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO= )(s)+3HCl(g)+7H{sub 2}O(l)was determined to be {delta}{sub r}H{sub m}{sup {theta}}=91.57+/-0.34kJmol{sup -1}. From data in the literature, through Hess' law, the standard molar enthalpy of formation of La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 7}NO) (s) was estimated to be {delta}{sub f}H{sub m}{sup {theta}}[La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO) (s), 298.15K]=- 2076.5+/-3.9kJmo0011l{sup -}.

  7. Kinetic energies of charged fragments resulting from multifragmentation and asymmetric fission of the C{sub 60} molecule in collisions with monocharged ions (2-130 keV)

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A; Bordenave-Montesquieu, D; Moretto-Capelle, P; Bordenave-Montesquieu, A [Laboratoire CAR-IRSAMC, UMR 5589 CNRS - Universite Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex (France)

    2003-04-28

    Multifragmentation and asymmetric fission (AF) of the C{sub 60} molecule induced by H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} ions at medium collision energies (2-130 keV) are considered. Momenta and kinetic energies of C{sub n}{sup +} fragment ions (n = 1- 12) are deduced from an analysis of time-of-flight spectra. In multifragmentation processes, momenta are found to be approximately constant when n > 2, a behaviour which explains that the most probable kinetic energy, as well as the width of the kinetic energy distributions, is found to be inversely proportional to the fragment size n; both momenta and kinetic energies are independent of the velocity and nature of the projectile, and hence of the energy deposit. A specific study of the AF shows that the kinetic energies of C{sub 2}{sup +}, C{sub 4}{sup +} and C{sub 6}{sup +} fragments are also independent of the collision velocity and projectile species; a quantitative agreement is found with values deduced from kinetic energy release measurements by another group in electron impact experiments, and the observed decrease when the mass of the light fragment increases is also reproduced. A quantitative comparison of AF and multifragmentation for the n = 2, 4 and 6 fragment ions shows that kinetic energies in AF exceed that in multifragmentation, a result which explains the oscillations observed when momenta or kinetic energies of fragments are plotted against the n-value. The AF yield is also found to scale with the energy deposit in the collision velocity range extending below the velocity at the maximum of the electronic stopping power; except for protons, it remains negligible with respect to multifragmentation as soon as the total energy deposit exceeds about 100 eV.

  8. One- and two-step spin-crossover behavior of [Fe(II)(isoxazole)(6)](2+) and the structure and magnetic properties of triangular [Fe(III)(3)O(OAc)(6)(isoxazole)(3)][ClO(4)].

    Science.gov (United States)

    Hibbs, Wendy; van Koningsbruggen, Petra J; Arif, Atta M; Shum, William W; Miller, Joel S

    2003-09-08

    The structure and spin-crossover magnetic behavior of [Fe(II)1(6)][BF(4)](2) (1 = isoxazole) and [Fe(II)1(6)][ClO(4)](2) have been studied. [Fe(II)1(6)][BF(4)](2) undergoes two reversible spin-crossover transitions at 91 and 192 K, and is the first two-step spin transition to undergo a simultaneous crystallographic phase transition, but does not exhibit thermal hysteresis. The single-crystal structure determinations at 260 [space group P3, a = 17.4387(4) A, c = 7.6847(2) A] and at 130 K [space group P1, a = 17.0901(2) A, b = 16.7481(2) A, c = 7.5413(1) A, alpha = 90.5309(6) degrees, beta = 91.5231(6) degrees, gamma = 117.8195(8) degrees ] reveal two different iron sites, Fe1 and Fe2, in a 1:2 ratio. The room-temperature magnetic moment of 5.0 mu(B) is consistent with high-spin Fe(II). A plateau in mu(T) having a moment of 3.3 mu(B) centered at 130 K suggests a mixed spin system of some high-spin and some low-spin Fe(II) molecules. On the basis of the Fe-N bond distances at the two temperatures, and the molar fraction of high-spin molecules at the transition plateau, Fe1 and Fe2 can be assigned to the 91 and 192 K transitions, respectively. [Fe(II)1(6)][ClO(4)](2) [space group P3, a = 17.5829(3) A, c = 7.8043(2) A, beta = 109.820 (3) degrees, T = 295 K] also possesses Fe1:Fe2 in a 1:2 ratio, and magnetic measurements show a single spin transition at 213 K, indicating that both Fe1 and Fe2 undergo a simultaneous spin transition. [Fe(II)1(6)][ClO(4)](2) slowly decomposes in solutions containing acetic anhydride to form [Fe(III)(3)O(OAc)(6)1(3)][ClO(4)] [space group I2, a = 10.1547(7) A, b = 16.5497(11) A, c = 10.3205(9) A, beta = 109.820 (3) degrees, T = 200 K]. The isosceles Fe(3) unit contains two Fe.Fe distances of 3.2844(1) A and a third Fe.Fe distance of 3.2857(1) A. The magnetic data can be fit to a trinuclear model with H = -2J(S(1)xS(2) + S(2)xS(3)) - 2J(13)(S(1)xS(3)), where J = -27.1 and J(13) = -32.5 cm(-1).

  9. (enH2)(4.5)[In(As(V)S4)3][As2(III)(μ-S2)S3]Cl and (enH2)MnAs(III)As(V)S6: two thioarsenates(III, V) with mixed-valent optical properties.

    Science.gov (United States)

    Du, Ke-Zhao; Feng, Mei-Ling; Qi, Xing-Hui; Ma, Zu-Ju; Li, Long-Hua; Li, Jian-Rong; Du, Cheng-Feng; Zou, Guo-Dong; Huang, Xiao-Ying

    2014-02-21

    Two mixed-valent thioarsenates, namely (enH2)(4.5)[In(As(V)S4)3][As2(III)(μ-S2)S3]Cl (1) and (enH2)MnAs(III)As(V)S6 (2) (en = ethylenediamine), have been solvothermally synthesized and characterized. Thermal stability, magnetic and mixed-valent optical properties, as well as theoretical band structures and DOSs, of 1 and 2 have also been studied.

  10. Effects of La{sub 2}O{sub 3} on microstructure and wear properties of laser clad {gamma}/Cr{sub 7}C{sub 3}/TiC composite coatings on TiAl intermatallic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiubo [Laboratory for Laser Intelligent Manufacturing, Institute of Mechanics, Chinese Academy of Sciences, 15 Beisihuanxi Road, Beijing 100080 (China) and School of Materials and Chemical Engineering, Zhongyuan Institute of Technology, 41 Zhongyuan Western Road, Zhengzhou 450007, Henan Province (China)]. E-mail: liubobo0828@yahoo.com.cn; Yu Rongli [School of Materials Science and Engineering, Beihang University, 37 Xueyuan Road, Beijing 100083 (China)

    2007-02-15

    The effects of La{sub 2}O{sub 3} addition on the microstructure and wear properties of laser clad {gamma}/Cr{sub 7}C{sub 3}/TiC composite coatings on {gamma}-TiAl intermetallic alloy substrates with NiCr-Cr{sub 3}C{sub 2} precursor mixed powders have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive spectrometer (EDS) and block-on-ring wear tests. The responding wear mechanisms are discussed in detail. The results are compared with that for composite coating without La{sub 2}O{sub 3}. The comparison indicates that no evident new crystallographic phases are formed except a rapidly solidified microstructure consisting of the primary hard Cr{sub 7}C{sub 3} and TiC carbides and the {gamma}/Cr{sub 7}C{sub 3} eutectics distributed in the tough {gamma} nickel solid solution matrix. Good finishing coatings can be achieved under a proper amount of La{sub 2}O{sub 3}-addition and a suitable laser processing parameters. The additions of rare-earth oxide La{sub 2}O{sub 3} can refine and purify the microstructure of coatings, relatively decrease the volume fraction of primary blocky Cr{sub 7}C{sub 3} to Cr{sub 7}C{sub 3}/{gamma} eutectics, reduce the dilution of clad material from base alloy and increase the microhardness of the coatings. When the addition of La{sub 2}O{sub 3} is approximately 4 wt.%, the laser clad composite coating possesses the highest hardness and toughness. The composite coating with 4 wt.%La{sub 2}O{sub 3} addition can result the best enhancement of wear resistance of about 30%. However, too less or excessive addition amount of La{sub 2}O{sub 3} have no better influence on wear resistance of the composite coating.

  11. On the output factor measurements of the CyberKnife iris collimator small fields: Experimental determination of the k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors for microchamber and diode detectors

    Energy Technology Data Exchange (ETDEWEB)

    Pantelis, E.; Moutsatsos, A.; Zourari, K.; Petrokokkinos, L.; Sakelliou, L.; Kilby, W.; Antypas, C.; Papagiannis, P.; Karaiskos, P.; Georgiou, E.; Seimenis, I. [Medical Physics Laboratory, Medical School, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece) and CyberKnife Center, Iatropolis-MagnitikiTomografia, 54-56 Ethnikis-Antistaseos, 152 31 Athens (Greece); Medical Physics Laboratory, Medical School, University of Athens, 75 Mikras Asias, 115 27 Athen (Greece); Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece); Accuray Incorporated, Sunnyvale, California 94089 (United States); 1st Department of Radiology, Aretaieion Hospital, Medical School, University of Athens, Vas. Sophias, 115 28 Athens (Greece) and CyberKnife Center, Iatropolis-MagnitikiTomografia, 54-56 Ethnikis-Antistaseos, 152 31 Athens (Greece); Medical Physics Laboratory, Medical School, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece); Medical Physics Laboratory, Medical School, Democritus University of Thrace, 2nd Building of Preclinical Section, University Campus, 68100 Alexandroupolis (Greece)

    2012-08-15

    Purpose: To measure the output factors (OFs) of the small fields formed by the variable aperture collimator system (iris) of a CyberKnife (CK) robotic radiosurgery system, and determine the k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors for a microchamber and four diode detectors. Methods: OF measurements were performed using a PTW PinPoint 31014 microchamber, four diode detectors (PTW-60017, -60012, -60008, and the SunNuclear EDGE detector), TLD-100 microcubes, alanine dosimeters, EBT films, and polymer gels for the 5 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm iris collimators at 650 mm, 800 mm, and 1000 mm source to detector distance (SDD). The alanine OF measurements were corrected for volume averaging effects using the 3D dose distributions registered in polymer gel dosimeters. k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors for the PinPoint microchamber and the diode dosimeters were calculated through comparison against corresponding polymer gel, EBT, alanine, and TLD results. Results: Experimental OF results are presented for the array of dosimetric systems used. The PinPoint microchamber was found to underestimate small field OFs, and a k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factor ranging from 1.127 {+-} 0.022 (for the 5 mm iris collimator) to 1.004 {+-} 0.010 (for the 15 mm iris collimator) was determined at the reference SDD of 800 mm. The PinPoint k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factor was also found to increase with decreasing SDD; k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} values equal to 1.220 {+-} 0.028 and 1.077 {+-} 0

  12. Study of the fragmentation of astrophysical interest molecules (C{sub n}H{sub m}) induced by high velocity collision; Etude de la fragmentation de molecules d'interet astrophysique de type C{sub n}H{sub m} par collision atomique de haute vitesse

    Energy Technology Data Exchange (ETDEWEB)

    Tuna, Th

    2008-07-15

    This work shows the study of atom-molecule collision processes in the high velocity domain (v=4,5 a.u). The molecules concerned by this work are small unsaturated hydrocarbons C{sub 1-4}H and C{sub 3}H{sub 2}. Molecules are accelerated with the Tandem accelerator in Orsay and their fragmentation is analyzed by the 4{pi}, 100% efficient detector, AGAT. Thanks to a shape analysis of the current signal from the silicon detectors in association with the well known grid method, we are able to measure all the fragmentation channels of the incident molecule. These dissociation measurements have been introduced in the modelization of two objects of the interstellar medium in which a lot of hydrocarbon molecules have been observed (TMC1, horse-head nebula). We have extended our branching ratios obtained by high velocity collision to other electronic processes included in the chemical database like photodissociation and dissociative recombination. This procedure is feasible under an assumption of the statistical point of view of the molecular fragmentation. The deviations following our modification are very small in the modelization of TMC1 but significant in the photodissociation region. The first part is dedicated to the description of the experimental setting that has enabled us to study the fragmentation of C{sub n}H{sub m} molecules: the Orsay's Tandem accelerator and the Agat detector. The second part deals with negative ion sources and particularly with the Sahat source that is based on electronic impact and has shown good features for the production of anions and correct stability for its use with accelerators. The third part is dedicated to the experimental results in terms of cross-sections, number of fragments and branching ratios, associated to the various collisional processes. The last part presents an application of our measurement of fragmentation data to astro-chemistry. In this field, the simulation codes of the inter-stellar medium require databases

  13. Volumetric properties and enthalpies of solution of alcohols C{sub k}H{sub 2k+1}OH (k = 1, 2, 6) in 1-methyl-3-alkylimidazolium bis(trifluoromethylsulfonyl)imide {l_brace}[C{sub 1}C{sub n}Im][NTf{sub 2}] n = 2, 4, 6, 8, 10{r_brace} ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Y. [CNRS, Laboratoire Thermodynamique et Interactions Moleculaires, UMR 6272, 24 avenue des Landais, 63177 Aubiere Cedex (France); Husson, P. [CNRS, Laboratoire Thermodynamique et Interactions Moleculaires, UMR 6272, 24 avenue des Landais, 63177 Aubiere Cedex (France); Clermont Universite, Universite Blaise Pascal, Laboratoire Thermodynamique et Interactions Moleculaires, UMR 6272, 63177 Aubiere Cedex (France); Jacquemin, J. [The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen' s University of Belfast, Stranmillis Road, Belfast BT9 5AG (United Kingdom); Universite Francois Rabelais, Laboratoire PCMB (EA 4244), equipe Chimie-physique des Interfaces et des Milieux Electrolytiques (CIME), Parc de Grandmont, 37200 Tours (France); Youngs, T.G.A. [The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen' s University of Belfast, Stranmillis Road, Belfast BT9 5AG (United Kingdom); Kett, V.L. [The School of Pharmacy, The Queen' s University of Belfast, 97 Lisburn Road, Belfast BT9 7BL (United Kingdom); Hardacre, C. [The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen' s University of Belfast, Stranmillis Road, Belfast BT9 5AG (United Kingdom); Costa Gomes, M.F., E-mail: margarida.c.gomes@univ-bpclermont.fr [CNRS, Laboratoire Thermodynamique et Interactions Moleculaires, UMR 6272, 24 avenue des Landais, 63177 Aubiere Cedex (France); Clermont Universite, Universite Blaise Pascal, Laboratoire Thermodynamique et Interactions Moleculaires, UMR 6272, 63177 Aubiere Cedex (France)

    2011-11-15

    Highlights: > Excess properties of (ionic liquid + alcohol) mixtures. > Volumetric properties, excess molar volumes. > Heats of mixing of (ionic liquid + alcohol) mixtures. > Molecular simulation of (ionic liquid + alcohol) mixtures. - Abstract: We present a study on the effect of the alkyl chain length of the imidazolium ring in 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids, [C{sub 1}C{sub n}Im][NTf{sub 2}] (n = 2 to 10), on the mixing properties of (ionic liquid + alcohol) mixtures (enthalpy and volume). We have measured small excess molar volumes with highly asymmetric curves as a function of mole fraction composition (S-shape) with more negative values in the alcohol-rich regions. The excess molar volumes increase with the increase of the alkyl-chain length of the imidazolium cation of the ionic liquid. The values of the partial molar excess enthalpy and the enthalpy of mixing are positive and, for the case of methanol, do not vary monotonously with the length of the alkyl side-chain of the cation on the ionic liquid - increasing from n = 2 to 6 and then decreasing from n = 8. This non-monotonous variation is explained by a more favourable interaction of methanol with the cation head group of the ionic liquid for alkyl chains longer than eight carbon atoms. It is also observed that the mixing is less favourable for the smaller alcohols, the enthalpy of mixing decreasing to less positive values as the alkyl chain of the alcohol increases. Based on the data from this work and on the knowledge of the vapour pressure of {l_brace}[C{sub 1}C{sub n}Im][NTf{sub 2}] + alcohol{r_brace} binary mixtures at T = 298 K reported in the literature, the excess Gibbs free energy, excess enthalpy and excess entropy could be then calculated and it was observed that these mixtures behave like the ones constituted by a non-associating and a non-polar component, with its solution behaviour being determined by the enthalpy.

  14. The Effects of Heat Treatments on the M{sub 23}C{sub 6} Carbide Evolution and Grain Boundary Serration in Alloy 690

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Yun Soo; Kim, Dong Jin; Hwang, Seong Sik; Kim, Sung Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Some laboratory tests revealed that Alloy 690 is resistant to IGSCC in various environments. With a prolonged service life and improved performance being demanded by the nuclear energy industry, however, the need to improve the resistance to intergranular failure in Alloy 690 should also be considered. The present work is an attempt to elucidate the effects of various heat treatments on the evolutions of intergranular carbide precipitation and the grain boundary serration (GBS) in Alloy 690 to acquire a high resistance to intergranular degradations. By isothermal treatments at 720 .deg. C for 0.1-100 hr after solution annealing, most of the grain boundaries except for the coherent twin boundaries were decorated with well-developed M{sub 23}C{sub 6} carbides. The discontinuous precipitates were initiated on the grain boundary even by a heat treatment of 0.1 hr, and covered the entire grain boundary region within a heat treatment of 10 hr. With a long aging time of 100 hr, intragranular Cr carbides were precipitated on the imperfections such as the dislocations and stacking faults GBS could be introduced by a slow cooling process in this alloy, and occurred in a limited temperature range of 990-900 .deg. C under the present heat treatment conditions. The grain boundaries had a convex shape into the incoherent grain, from which it is believed that the grain boundary shape is closely associated with the grain boundary migration during serration in this alloy.

  15. Equilibrium partitioning theory to predict the sediment toxicity of the anionic surfactant C{sub 12}-2-LAS to Corophium volutator

    Energy Technology Data Exchange (ETDEWEB)

    Rico-Rico, Angeles [Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3508 TD, Utrecht (Netherlands)], E-mail: a.ricorico@uu.nl; Temara, Ali [Procter and Gamble Company, Central Product Safety, Temselaan 100, 1853 Strombeek-Bever (Belgium); Hermens, Joop L.M. [Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3508 TD, Utrecht (Netherlands)

    2009-02-15

    The study of the effect of the sorption of linear alkylbenzene sulfonates (LAS) on the bioavailability to marine benthic organisms is essential to refine the environmental risk assessment of these compounds. According to the equilibrium partitioning theory (EqP), the effect concentration in water-only exposure will be similar to the effect concentration in the sediment pore water. In this work, sorption and desorption experiments with two marine sediments were carried out using the compound C{sub 12}-2-LAS. The effect of the sediment sorption on the toxicity of benthic organisms was studied in water-only and in sediment bioassays with the marine mud shrimp Corophium volutator. In addition, three common spiking methods were tested for its application in the toxicity tests, as well as the stability of the surfactant during the water-only and sediment-water test duration. LC50 values obtained from water-only exposure showed a good correspondence with the pore water concentrations calculated from the sorption and desorption isotherms in the spiked sediments. - The toxicity of linear alkylbenzene sulfonate to Corophium volutator in marine sediments can be predicted from toxicity measured via water-only exposure.

  16. The (p, {rho}, T) properties and apparent molar volumes V{sub {phi}} of (ZnBr{sub 2} + C{sub 2}H{sub 5}OH)

    Energy Technology Data Exchange (ETDEWEB)

    Guliyev, Tavakkul [Department of Heat and Refrigeration Techniques, Azerbaijan Technical University, H. Javid Avn. 25, AZ1073 Baku (Azerbaijan); Safarov, Javid [Department of Heat and Refrigeration Techniques, Azerbaijan Technical University, H. Javid Avn. 25, AZ1073 Baku (Azerbaijan); Lehrstuhl fuer Technische Thermodynamik, Universitaet Rostock, 18059 Rostock (Germany)], E-mail: javid.safarov@uni-rostock.de; Shahverdiyev, Astan [Department of Heat and Refrigeration Techniques, Azerbaijan Technical University, H. Javid Avn. 25, AZ1073 Baku (Azerbaijan); Hassel, Egon [Lehrstuhl fuer Technische Thermodynamik, Universitaet Rostock, 18059 Rostock (Germany)

    2009-10-15

    The (p, {rho}, T) properties and apparent molar volumes V{sub {phi}} of ZnBr{sub 2} in ethanol at temperatures (293.15 to 393.15) K and pressures up to p = 40 MPa are reported. The measurements were made with a recently developed vibration-tube densimeter. The system was calibrated using double-distilled water, methanol, ethanol, and aqueous NaCl solutions. The experiments were carried out at molalities of m = (0.05681, 0.16958, 0.30426, 0.43835, 0.93055, 1.49016, and 1.88723) mol . kg{sup -1} using zinc bromide. An empirical correlation for the density of (ZnBr{sub 2} + C{sub 2}H{sub 5}OH) with pressure, temperature, and molality has been derived. This equation of state was used to calculate other volumetric properties such as isothermal compressibility, isobaric thermal expansibility, the differences in specific heat capacities at constant pressures and volumes, apparent molar volumes of ZnBr{sub 2} in ethanol, and partial molar volumes of both components.

  17. Computer simulations of material ejection during C{sub 60} and Ar{sub m} bombardment of octane and β-carotene

    Energy Technology Data Exchange (ETDEWEB)

    Palka, G.; Kanski, M.; Maciazek, D. [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow (Poland); Garrison, B.J. [Department of Chemistry, 104 Chemistry Building, Penn State University, University Park, PA 16802 (United States); Postawa, Z., E-mail: zbigniew.postawa@uj.edu.pl [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow (Poland)

    2015-06-01

    Molecular dynamics (MD) computer simulations are used to investigate material ejection and fragment formation during keV C{sub 60} and Ar{sub m} (m = 60, 101, 205, 366, 872 and 2953) bombardment of organic solids composed from octane and β-carotene molecules at 0° and 45° impact angle. Both systems are found to sputter efficiently. For the octane system, material removal occurs predominantly by ejection of intact molecules, while fragment emission is a significant ejection channel for β-carotene. A difference in the molecular dimensions is proposed to explain this observation. It has been shown that the dependence of the sputtering yield Y on the primary kinetic energy E and the cluster size n can be expressed in a simplified form if represented in reduced units. A linear and nonlinear dependence of the Y/n on the E/n are identified and the position of the transition point from the linear to nonlinear regions depends on the size of the cluster projectile. The impact angle has a minor influence on the shape of the simplified representation.

  18. Comparison of the backbone dynamics of wild-type Hydrogenobacter thermophilus cytochrome c{sub 552} and its b-type variant

    Energy Technology Data Exchange (ETDEWEB)

    Tozawa, Kaeko; Ferguson, Stuart J.; Redfield, Christina, E-mail: christina.redfield@bioch.ox.ac.uk [University of Oxford, Department of Biochemistry (United Kingdom); Smith, Lorna J., E-mail: lorna.smith@chem.ox.ac.uk [University of Oxford, Department of Chemistry (United Kingdom)

    2015-06-15

    Cytochrome c{sub 552} from the thermophilic bacterium Hydrogenobacter thermophilus is a typical c-type cytochrome which binds heme covalently via two thioether bonds between the two heme vinyl groups and two cysteine thiol groups in a CXXCH sequence motif. This protein was converted to a b-type cytochrome by substitution of the two cysteine residues by alanines (Tomlinson and Ferguson in Proc Natl Acad Sci USA 97:5156–5160, 2000a). To probe the significance of the covalent attachment of the heme in the c-type protein, {sup 15}N relaxation and hydrogen exchange studies have been performed for the wild-type and b-type proteins. The two variants share very similar backbone dynamic properties, both proteins showing high {sup 15}N order parameters in the four main helices, with reduced values in an exposed loop region (residues 18–21), and at the C-terminal residue Lys80. Some subtle changes in chemical shift and hydrogen exchange protection are seen between the wild-type and b-type variant proteins, not only for residues at and neighbouring the mutation sites, but also for some residues in the heme binding pocket. Overall, the results suggest that the main role of the covalent linkages between the heme group and the protein chain must be to increase the stability of the protein.

  19. Latent tracks of swift heavy ions in Cr{sub 23}C{sub 6} and Y–Ti–O nanoparticles in ODS alloys

    Energy Technology Data Exchange (ETDEWEB)

    Skuratov, V.A., E-mail: skuratov@jinr.ru [FLNR, JINR, Dubna (Russian Federation); Sohatsky, A.S. [FLNR, JINR, Dubna (Russian Federation); O’Connell, J.H. [CHRTEM, NMMU, Port Elizabeth (South Africa); Kornieieva, K. [FLNR, JINR, Dubna (Russian Federation); Nikitina, A.A. [JSC VNIINM, Moscow (Russian Federation); Uglov, V.V. [Belarusian State University, Minsk (Belarus); Neethling, J.H. [CHRTEM, NMMU, Port Elizabeth (South Africa); Ageev, V.S. [JSC VNIINM, Moscow (Russian Federation)

    2016-05-01

    The radiation stability of dielectric nanoparticles embedded into a metallic matrix is of considerable practical value due to the growing interest in oxide dispersion strengthened (ODS) steels as promising nuclear reactor materials. In this report the results of a TEM study of structural changes in Cr{sub 23}C{sub 6} and Y–Ti–O nanoparticles in several ODS alloys irradiated with 1.2 MeV/amu Xe and 3.4 MeV/amu Bi ions is presented. It was found that swift heavy ion irradiation leads to the formation of amorphous latent tracks in both materials. The upper limit of the threshold electronic stopping power for track formation in carbides is estimated to be around 35 keV/nm. Multiple ion track overlapping leads to complete amorphization of carbide and Y–Ti oxide nanoparticles. Microstructural analysis have revealed a strong influence of the ferritic matrix on track morphology in Y{sub 2}Ti{sub 2}O{sub 7} nanoparticles in pre-thinned TEM targets after postradiation annealing and irradiation at elevated temperatures.

  20. C{sub 16}H{sub 10} ethynyl-substituted polycyclic aromatic hydrocarbons from the pyrolysis of coal, coal volatiles, and anthracene

    Energy Technology Data Exchange (ETDEWEB)

    Wornat, M.J.; Ledesma, E.B. [Princeton University, Princeton, NJ (USA). Dept. Mechanical & Aerospace Engineering

    2000-07-01

    The acquisition of several specially synthesized reference standards of ethynyl-substituted three-ring polycyclic aromatic hydrocarbons (PAH) has enabled the identification, for the first time, of two C{sub 16}H{sub 10} ethynyl-PAH among the pyrolysis products of coal and coal-derived fuels. The fuel product mixtures are analyzed by high-pressure liquid chromatography (HPLC) with diode-array ultraviolet (UV) absorbance detection. 2-ethynylanthracene and 2-ethynylphenanthrene were identified among the pyrolysis products of brown coal, pyrolyzed at 1000{degree}C in a fluidized-bed reactor, and of bituminous coal volatiles, pyrolyzed at 1000{degree}C in a tubular flow reactor. 2-ethynylanthracene were observed as a pyrolysis product, at 1300 to 1500K, of anthracene, a three-ring model compound representative of the aromatic moieties in coal. The identification of these ethynyl-PAH provides important experimental evidence that acetylene addition to aryl radicals indeed takes place in these fuel reaction environments, as is customarily assumed in modelling of PAH growth during combustion. One experimental observations were consistent with theoretical calculations showing that the formation of cyclopenta-fused PAH by cyclization, when allowed, is energetically favored over the production of ethynyl-PAH.

  1. Solidification structure of C{sub 2.08}Cr{sub 25.43}Si{sub 1.19}Mn{sub 0.43}Fe{sub 70.87} powders fabricated by high pressure gas atomization

    Energy Technology Data Exchange (ETDEWEB)

    Dai Yongxiang; Yang Min; Song Changjiang [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai (China); Han, Qingyou [Mechanical Engineering Technology Department, Purdue University (United States); Zhai Qijie, E-mail: qjzhai@shu.edu.cn [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai (China)

    2010-01-15

    Powders of hypoeutectic high chromium white cast iron (C{sub 2.08}Cr{sub 25.43}Si{sub 1.19}Mn{sub 0.43}Fe{sub 70.87}) were produced by high pressure gas atomization. The microstructure of the powders was characterized using light microscopy, scanning electron microscopy and X-ray diffraction. The results showed that the as-atomized powders were mainly composed of austenite and M{sub 7}C{sub 3} (M = Fe, Cr) type carbide, and became ferrite and carbide after annealing. With the decrease of the powder diameter, the number of austenite grains, primary dendrite length and second dendrite arm spacing were decreased. The relationship between cooling rate and microstructure was also determined.

  2. Surface-induced intramolecular electron transfer in multi-centre redox metalloproteins: the di-haem protein cytochrome c{sub 4} in homogeneous solution and at electrochemical surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Chi Qijin; Zhang Jingdong; Jensen, Palle S; Ulstrup, Jens [Department of Chemistry, Technical University of Denmark, Building 207, DK-2800 Kongens Lyngby (Denmark); Nazmudtinov, Renat R [Kazan State Technological University, 420015 Kazan, Republic of Tatarstan (Russian Federation)

    2008-09-17

    Intramolecular electron transfer (ET) between transition metal centres is a core feature of biological ET and redox enzyme function. The number of microscopic redox potentials and ET rate constants is, however, mostly prohibitive for experimental mapping, but two-centre proteins offer simple enough communication networks for complete mapping to be within reach. At the same time, multi-centre redox proteins operate in a membrane environment where conformational dynamics and ET patterns are quite different from the conditions in a homogeneous solution. The bacterial respiratory di-haem protein Pseudomonas stutzeri cytochrome c{sub 4} offers a prototype target for environmental gating of intra-haem ET. ET between P. stutzeri cyt c{sub 4} and small molecular reaction partners in solution appears completely dominated by intermolecular ET of each haem group/protein domain, with no competing intra-haem ET, for which accompanying propionate-mediated proton transfer is a further barrier. The protein can, however, be immobilized on single-crystal, modified Au(111) electrode surfaces with either the low-potential N terminal or the high-potential C terminal domain facing the surface, clearly with fast intramolecular ET as a key feature in the electrochemical two-ET process. This dual behaviour suggests a pattern for multi-centre redox metalloprotein function. In a homogeneous solution, which is not the natural environment of cyt c{sub 4}, the two haem group domains operate largely independently with conformations prohibitive for intramolecular ET. Binding to a membrane or electrochemical surface, however, triggers conformational opening of intramolecular ET channels. The haem group orientation in P. stutzeri cyt c{sub 4} is finally noted to offer a case for orientation dependent electronic rectification between a substrate and a tip in electrochemical in situ scanning tunnelling microscopy or nanoscale electrode configurations.

  3. Synthesis, structure and electronic configuration of [Rh{sub 6}Te{sub 8}(PPh{sub 3}){sub 6}].4C{sub 6}H{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Thiele, Guenther; Balmer, Markus [Marburg Univ. (Germany). Fachbereich Chemie; Dehnen, Stefanie [Marburg Univ. (Germany). Fachbereich Chemie and Wissenschaftliches Zentrum fuer Materialwissenschaften

    2016-08-01

    [Rh{sub 6}Te{sub 8}(PPh{sub 3}){sub 6}].4C{sub 6}H{sub 6}, the first compound with a molecular Chevrel-type [Rh{sub 6}Te{sub 8}] cluster core has been synthesized and structurally characterized. By means of quantum chemical calculation, the close relationship of its electronic configuration to that of the lighter homologue has been demonstrated. The different crystal solvent content prevents an isostructural crystallization.

  4. Stereoselective synthesis of stable isotope labeled L-[alpha]-amino acids: synthesis of L-[4-[sup 13]C] and L-[3,4,-[sup 13]C[sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Lodwig, S.N. (Centralia College, WA (United States). Science Div.); Unkefer, C.J. (Los Alamos National Lab., NM (United States))

    1992-02-01

    We have developed a stereoselective route to isotopically labeled L-aspartic acid using L-serine as a chiral precursor. Labeled serine, prepared biosynthetically was N-protected by conversion to the N-t-Boc derivative. (N-t-Boc)-[3-[sup 13]C]Serine is cyclized to its [beta]-lactone which was treated with potassium [[sup 13]C]cyanide to yield L-[beta]-[3,4-[sup 13]C[sub 2

  5. High temperature oxidation studies of detonation-gun-sprayed Cr{sub 3}C{sub 2}-NiCr coating on Fe- and Ni-based superalloys in air under cyclic condition at 900 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, Subhash [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, IIT Roorkee Campus, Roorkee 247667, Uttaranchal (India); Jayaganthan, R. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, IIT Roorkee Campus, Roorkee 247667, Uttaranchal (India)], E-mail: rjayafmt@iitr.ernet.in; Prakash, S. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, IIT Roorkee Campus, Roorkee 247667, Uttaranchal (India)

    2009-03-20

    The cyclic oxidation behavior of detonation-gun-sprayed Cr{sub 3}C{sub 2}-NiCr coating on three different superalloys namely Superni 75, Superni 718 and Superfer 800H at 900 deg. C for 100 cycles in air under cyclic heating and cooling conditions has been investigated in the present work. The kinetics of oxidation of coated and bare superalloys was analysed, using thermogravimetric technique. It was observed that all the coated and bare superalloys obey a parabolic rate law of oxidation. X-ray diffraction, FE-SEM/EDAX and X-ray mapping techniques were used to analyse the oxidation products of coated and bare superalloys. The results on the Cr{sub 3}C{sub 2}-NiCr-coated superalloys showed better oxidation resistance due to the formation of a compact and adhesive thin Cr{sub 2}O{sub 3} scale on the surface of the coating during oxidation. The scale remained intact and adherent to the partially oxidised coating during cyclic oxidation due to its good compatibility and similar thermal expansion coefficient between Cr{sub 3}C{sub 2}-NiCr coating and the superalloy substrates. In all the coated superalloys, the chromium, iron, silicon and titanium were oxidised in the inter-splat region, whereas splats which consisted mainly of Ni remained unoxidised. The parabolic rate constants of Cr{sub 3}C{sub 2}-NiCr-coated alloys were lower than that of the bare superalloys as observed in the present work.

  6. Synthesis and X-ray structural investigation of K{sub 2}(H{sub 5}O{sub 2})[UO{sub 2}(C{sub 2}O{sub 4}){sub 2}(HSeO{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Pushkin, D. V., E-mail: pushkin@ssu.samara.ru [Samara State University (Russian Federation); Peresypkina, E. V. [Russian Academy of Sciences, Nikolaev Institute of Inorganic Chemistry, Siberian Branch (Russian Federation); Serezhkina, L. B.; Marukhnov, A. V. [Samara State University (Russian Federation); Virovets, A. V. [Russian Academy of Sciences, Nikolaev Institute of Inorganic Chemistry, Siberian Branch (Russian Federation)

    2011-05-15

    The synthesis and X-ray diffraction analysis of K{sub 2}(H{sub 5}O{sub 2})[UO{sub 2}(C{sub 2}O{sub 4}){sub 2}(HSeO{sub 3})] single crystals have been performed. This compound crystallizes in the triclinic system with the unit-cell parameters a = 6.7665(4) Angstrom-Sign , b = 8.8850(4) Angstrom-Sign , c = 12.3147(7) Angstrom-Sign , {alpha} = 94.73 Degree-Sign , {beta} = 90.16 Degree-Sign , {gamma} = 92.11 Degree-Sign , sp. gr. P1-bar, Z = 2, and R = 0.019. The basic structural units are island [UO{sub 2}(C{sub 2}O{sub 4}){sub 2}(HSeO{sub 3})]{sup 3-} groups, which belong to the AB{sub 2}{sup 01}M{sup 1} crystallochemical group of uranyl complexes (A = UO{sub 2}{sup 2+}, B{sup 01} = C{sub 2}O{sub 4}{sup 2-}, and M{sub 1} = HSeO{sub 3}{sup -}). Uraniumcontaining complexes are linked through K{sup +} and H{sub 5}O{sub 2}{sup +} ions and via a system of hydrogen bonds with the participation of oxonium hydrogen atoms in this structure.

  7. Evidence and detailed study of a second-order phase transition in the (C{sub 6}H{sub 11}NH{sub 3}){sub 2}[PbI{sub 4}] organic-inorganic hybrid material

    Energy Technology Data Exchange (ETDEWEB)

    Yangui, A. [Groupe d' Etudes de la Matière Condensée, CNRS-Université de Versailles Saint Quentin En Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles (France); Laboratoire de Physique Appliquée, Faculté des Sciences de Sfax, Route de Soukra km 3.5 BP 1171, 3018 Sfax (Tunisia); Pillet, S. [Laboratoire de Cristallographie, Résonance Magnétique et Modélisations, UMR-CNRS 7036, Institut Jean Barriol, Université de Lorraine, BP 239, 54506 Vandoeuvre-lès-Nancy (France); Garrot, D.; Boukheddaden, K., E-mail: kbo@physique.uvsq.fr [Groupe d' Etudes de la Matière Condensée, CNRS-Université de Versailles Saint Quentin En Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles (France); Triki, S. [UMR CNRS 6521, Chimie, Electrochimie Moléculaires, Chimie Analytique, Université de Bretagne Occidentale, BP 809, 29285 Brest (France); Abid, Y. [Laboratoire de Physique Appliquée, Faculté des Sciences de Sfax, Route de Soukra km 3.5 BP 1171, 3018 Sfax (Tunisia)

    2015-03-21

    The thermal properties of the organic-inorganic hybrid material (C{sub 6}H{sub 11}NH{sub 3}){sub 2}[PbI{sub 4}] are investigated using diffuse reflectivity, spectroscopic ellipsometry, differential scanning calorimetry, Raman spectroscopy, and X-ray diffraction. The diffuse reflectivity, performed in heating mode, clearly evidences the presence of a singularity at 336 K. This is confirmed by the temperature dependence of the spectroscopic ellipsometry spectra, which points out a second-order phase transition at 336 K with a critical exponent ∼0.5. Differential scanning calorimetry measurements on a polycrystalline powder of (C{sub 6}H{sub 11}NH{sub 3}){sub 2}[PbI{sub 4}] show a reversible phase transition detected at T{sub C} = 336 K without hysteresis. Raman spectroscopy data suggest that this transition arises from a change in the interactions between inorganic sheets (([PbI{sub 4}]{sup 2−}){sub ∞}) and organic protonated molecules ([C{sub 6}H{sub 11}NH{sub 3}]{sup +}). The structural analysis from power X-ray diffraction reveals an incomplete order-disorder transition of the cyclohexylammonium cation, causing a subtle contraction of the inter-plane distance. The transition results from repulsive close contacts between the organic molecules in the interlayer spacing.

  8. Isomeric and concentration effects of C{sub 4}-cosurfactants on four-component microemulsions investigated by neutron spin-echo and small-angle scattering

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano, E [Center for Materials Science and Engineering, Rochester Institute of Technology, Rochester, NY 14623 (United States); Kotlarchyk, M [Department of Physics, Rochester Institute of Technology, Rochester, NY 14623 (United States); Langner, A [Department of Chemistry, Rochester Institute of Technology, Rochester, NY 14623 (United States); Faraone, A [NIST Center for Neutron Research, Gaithersburg, MD 20899 (United States)

    2006-09-13

    Neutron spin-echo spectroscopy and small-angle scattering measurements were performed to determine how the isomeric structure and concentration of C{sub 4}-cosurfactants (i.e. butyl alcohols) influence structure and dynamics in four-component water-in-oil microemulsions. The system investigated was AOT/butanol/water/n-octane at room temperature (AOT denotes sodium di-2-ethyl hexylsulfosuccinate), deuterated to achieve contrast of the surfactant/cosurfactant film. At a fixed volume fraction of 0.06 and a fixed molar ratio of [water]/[AOT] = 20, we studied the effects of increasing the molar ratio of [butanol]/[AOT] from 0 to 30. Data from samples containing the cosurfactant n-butyl alcohol were compared with samples prepared with tert-butyl alcohol and, in a few cases, sec-butyl alcohol. Data were analysed using a core-shell model for polydisperse spherical droplets, allowing for the presence of shape fluctuations. It was found that all structural isomers of the cosurfactant led to a similar decrease in droplet size with increasing alcohol content. In all cases, droplet size and shape fluctuations were observed to increase with alcohol content; however, the effect was most pronounced for size fluctuations (i.e. polydispersity) in the presence of tert-butanol. The data indicates that tert-butanol has a higher degree of penetration into the water core, leading to a reduced influence on the effective area per surfactant head group on the droplet surface. There is also evidence that an increased droplet-droplet attraction upon adding tert-butanol drives phase separation in the system.

  9. Seasonal dynamics of nutrient accumulation and partitioning in the perennial C{sub 4}-grasses Miscanthus x giganteus and Spartina cynosuroides

    Energy Technology Data Exchange (ETDEWEB)

    Beale, C.V. [Writtle College, Chelmsford (United Kingdom)] Long, S.P. [Essex Univ., Colchester (United Kingdom). Dept. of Biological and Chemical Sciences

    1997-12-31

    Seasonal variation in the accumulation and partitioning of nitrogen, phosphorus and potassium was determined in both the above-ground and below-ground dry matter of the potential energy crops Miscanthus x giganteus and Spartina cynosuroides. It is desirable from both economic and environmental perspectives that such crops should exhibit a high nutrient use efficiency and minimal nutrient losses to the environment. The N, P and K concentrations in the above-ground dry matter, at final harvest, were 5.0, 0.6 and 12.0 mg g{sup -1} respectively in M. x giganteus and 3.0, 0.4 and 1.0 mg g{sup -1} in S. cynosurodes. Both species exhibited the high N-use efficiency expected of C{sub 4} plants. Nitrate leaching was negligible. At the end of the growing season, nutrients were translocated to the rhizomes and, in the case of M. giganteus, recycled to the soil in shed leaves. Consequently the nutrient content of the crop offtake was low. It was calculated that the N, P and K requirements of a M. x giganteus crop producing an above-ground harvest of 1.5 kg m{sup -2} dry matter would be 9.2, .3 and 20.4 g m{sup -2} respectively. The corresponding nutrient requirements for S. cynosuroides would be 7.5, 1.7 and 8.8 g m{sup -2}. Except for the K requirements of M. x giganteus, the N, P and K demands of both species were less than those of typical graminaceous crops, including maize. (Author)

  10. C{sub 18}-attached membrane funnel-based spray ionization mass spectrometry for quantification of anti-diabetic drug from human plasma

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wan [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Chen, Xiangfeng, E-mail: xiangfchensdas@163.com [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Shandong Analysis and Test Centre, Shandong Academy of Sciences, Jinan, Shandong (China); Wong, Y.-L. Elaine; Hung, Y.-L. Winnie; Wang, Ze; Deng, Liulin [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Dominic Chan, T.-W., E-mail: twdchan@cuhk.edu.hk [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong)

    2016-08-24

    In this work, sorbent-attached membrane funnel-based spray ionization mass spectrometry was explored for quantitative analysis of anti-diabetic drugs spiked in human plasma. C{sub 18}-attached membrane funnel was fabricated for in situ extraction and clean-up to alleviate matrix suppression effect in the ionization process. Repaglinide was used as a target analyte of anti-diabetic drugs. Under optimal working conditions, good linearity (R{sup 2} > 0.99) was obtained in the concentration range of 1–100 ng mL{sup −1}. The method detection limit of target drugs spiked in the human plasma was around 0.30 ng mL{sup −1}. Through the application of an isotope-labeled internal standard, the signal fluctuation caused by residual background matrices was largely alleviated and the precision of measurement (RSD) was below 15%. The recovery of repaglinide for 5, 25, and 100 ng mL{sup −1} of spiked human plasma matrixes ranged from 87% to 112%. The developed method was successfully applied to determine repaglinide in plasma volunteers who orally received a dose of drug association. Our results demonstrated that membrane funnel-based spray is a simple and sensitive method for rapid screening analysis of complex biological samples. - Highlights: • Sorbent attached membrane funnel based spray platform was used for drug determination in human plasma. • The matrix suppression effect of human plasma was largely eliminated. • The method was applied to determine repaglinide in plasma volunteers. • Membrane funnel-based spray is promising for analysis of biological samples.

  11. Absolute number density and kinetic analysis of CF, CF{sub 2} and C{sub 2}F{sub 4} molecules in pulsed CF{sub 4}/H{sub 2} rf plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Stepanov, Sergey

    2010-04-26

    Tunable Diode Laser Absorption Spectroscopy in the mid InfraRed spectral range (IR-TDLAS) has been applied to investigate the behaviour of CF, CF{sub 2} and C{sub 2}F{sub 4} species produced in pulsed CF{sub 4}/H{sub 2} capacitively coupled radio frequency plasmas (13.56 MHz CCP). This experimental technique was shown to be suitable for temporally resolved measurements of the absolute number density of the target molecules in the studied fluorocarbon discharges. The temporal resolution of about 20..40 ms typically achieved in the standard data acquisition mode (''stream mode'') was sufficient for the real-time measurements of CF{sub 2} and C{sub 2}F{sub 4}, but not of CF whose kinetics was observed to be much faster. Therefore, a more sophisticated approach (''burst mode'') providing a temporal resolution of 0.94 ms was established and successfully applied to CF density measurements. In order to enable the TDLAS measurements of the target species, preliminary investigations on their spectroscopic data had been carried out. In particular, pure C{sub 2}F{sub 4} has been produced in laboratory by means of vacuum thermal decomposition (pyrolysis) of polytetrafluoroethylene and used as a reference gas. Therefore, an absorption structure consisting of several overlapping C{sub 2}F{sub 4} lines around 1337.11 cm{sup -1} was selected and carefully calibrated, which provided the first absolute measurements of the species by means of the applied experimental technique. The absolute number density traces measured for CF, CF{sub 2} and C{sub 2}F{sub 4} in the studied pulsed plasmas were then analysed, in which two differential balance equations were proposed for each of the species to describe their behaviour during both ''plasma on'' and ''plasma off'' phases. Analytical solutions of the balance equations were used to fit the experimental data and hence to deduce important information on the

  12. Pressure effects on the photoreactions of the iron acyl complex ([eta][sup 5]-C[sub 5]H[sub 5])Fe(CO)[sub 2](COCH[sub 3]). Mechanistic implications regarding competitive reactions of the solvento intermediate ([eta][sup 5]-C[sub 5]H[sub 5])Fe(CO)(Sol)(COCH[sub 3])

    Energy Technology Data Exchange (ETDEWEB)

    Ryba, D.W.; Eldik, R. van (Universitaet Witten/Herdecke (Germany)); Ford, P.C. (Univ. of California, Santa Barbara (United States))

    1993-01-01

    Photolysis of CpFe(CO)[sub 2](COCH[sub 3]) (Cp = [eta][sup 5]-C[sub 5]H[sub 5]) plus P(OCH[sub 3])[sub 3](L) in n-heptane solutions leads to the competitive decarbonylation to give CpFe(CO)[sub 2]CH[sub 3] and ligand substitution to give CpFe(CO)L(COCH[sub 3]). The application of hydrostatic pressure changes the relative quantum yields of the two processes, higher pressure strongly favoring the ligand photosubstitution pathway. These differences are interpreted in terms of the competitive reactions of the solvento intermediate CpFe(CO)(Sol)(COCH[sub 3]) (S), shown previously (J. Am. Chem. Soc. 1991, 113, 9524-9528) to be formed by the initial photolysis step, i.e., the labilization of CO. The much more negative apparent activation volume for the ligand substitution pathway suggest that this proceeds via an associative mechanism of S, while the competing methyl migration to the metal may require simultaneous dissociation of the coordinates solvent molecule, Sol. 16 refs., 1 fig.

  13. Thermodynamic study of binary mixture of x{sub 1}[C{sub 6}mim][BF{sub 4}] + x{sub 2}1-propanol: Measurements and molecular modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kermanpour, F., E-mail: kermanpour@basu.ac.ir [Faculty of Chemistry, Bu-Ali Sina University, Hamadan 65178-38695 (Iran, Islamic Republic of); Sharifi, T. [Faculty of Chemistry, Bu-Ali Sina University, Hamadan 65178-38695 (Iran, Islamic Republic of)

    2012-01-10

    Highlights: Black-Right-Pointing-Pointer Densities and viscosities for binary mixture of {l_brace}x{sub 1}[C{sub 6}mim][BF{sub 4}] + x{sub 2}1-propanol{r_brace} were measured at different temperatures. Black-Right-Pointing-Pointer The excess molar functions were calculated from the obtained experimental data. Black-Right-Pointing-Pointer These data were correlated with the Redlich-Kister equation and PFP model to obtain the coefficients and standard deviations. - Abstract: Densities, {rho}, and viscosities, {eta}, of pure 1-hexyl-3-methylimidazoliumtetrafluoro borate ([C{sub 6}mim][BF{sub 4}]) and 1-propanol, and their binary mixture {l_brace}x{sub 1}[C{sub 6}mim][BF{sub 4}] + x{sub 2}1-propanol{r_brace} were measured at atmospheric pressure and in the temperature range of 293.15-333.15 K. The excess molar volumes, V{sub m}{sup E}, thermal expansion coefficients, {alpha}, and their excess values, {alpha}{sup E}, isothermal coefficient of excess molar enthalpy, ({partial_derivative}H{sub m}{sup E}/{partial_derivative}p){sub T,x} and excess viscosities, {eta}{sup E}, were calculated from the experimental values of densities and viscosities. The excess molar volumes of the binary mixture are negative over the entire mole fraction range and increase with increasing temperature. Excess viscosities are negative over the entire mole fraction range of the mixture and decrease with increasing temperature. The obtained excess molar volumes and excess viscosities were correlated with the Redlich-Kister equation. The experimental results have also been used to examine the applicability of Prigogine-Flory-Patterson (PFP) theory in predicting the excess molar volume of the binary mixture. It is indicated that agreement between excess molar volumes calculated via PFP theory and the experimental results is good in all temperatures.

  14. Anti-adhesive characteristics of CHF{sub 3}/O{sub 2} and C{sub 4}F{sub 8}/O{sub 2} plasma-modified silicon molds for nanoimprint lithography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaemin; Lee, Junmyung [Department of Control and Instrumentation Engineering, Korea University, Sejong 339-700 (Korea, Republic of); Lee, Hyun Woo [Department of Electronics, Hanseo University, Seosan 356-706 (Korea, Republic of); Kwon, Kwang-Ho, E-mail: kwonkh@korea.ac.kr [Department of Control and Instrumentation Engineering, Korea University, Sejong 339-700 (Korea, Republic of)

    2015-09-15

    The anti-adhesive characteristics of a plasma-modified silicon mold surface for nanoimprint lithography are presented. Both CHF{sub 3}/O{sub 2} and C{sub 4}F{sub 8}/O{sub 2} plasma were used to form an anti-adhesive layer on silicon mold surfaces. The gas mixing ratios of CHF{sub 3}/O{sub 2} and C{sub 4}F{sub 8}/O{sub 2} were experimentally changed between 0% and 80% to optimize the plasma conditions to obtain a low surface energy of the silicon mold. The plasma characteristics were examined by optical emission spectroscopy (OES). In order to investigate the changes in surface energy and surface chemistry of the anti-adhesive layer during repeated demolding cycles, contact angle measurements and X-ray photoelectron spectroscopy (XPS) were performed on the plasma-modified silicon mold surface. Simultaneously, the surface morphology of the demolded resists was evaluated by field-emission scanning electron microscope (FE-SEM) in order to examine the effect of the anti-adhesive layers on the duplicated patterns of the resists. It was observed that the anti-adhesive layer formed by CHF{sub 3}/O{sub 2} plasma treatment was worn out more easily during repeated demolding cycles than the film formed by C{sub 4}F{sub 8}/O{sub 2} plasma treatment, because CHF{sub 3}/O{sub 2} gas plasma formed a thinner plasma-polymerized film over the same plasma treatment time.

  15. Structural, vibrational and optical properties of a new self assembled organic–inorganic nanowire crystal (C{sub 6}H{sub 14}N){sub 2}[BiBr{sub 5}]. A Density Functional Theory approach

    Energy Technology Data Exchange (ETDEWEB)

    Dammak, Hajer, E-mail: hajerdm@gmail.com [Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP1171, 3000 Sfax (Tunisia); Triki, Smail [UMR CNRS 6521, Chimie, Electrochimie Moléculaires, Chimie Analytique, Université de Bretagne Occidentale, BP 809, 29285 Brest Cedex (France); Mlayah, Adnen [Centre d’Elaboration de Matériaux et d’Etudes Structurales, CNRS-Université Paul Sabatier, 29 Rue Jeanne Marvig, 31055 Cedex 4 (France); Abid, Younes; Feki, Habib [Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP1171, 3000 Sfax (Tunisia)

    2015-10-15

    Single crystal and thin films of a new organic–inorganic hybrid material (C{sub 6}H{sub 14}N){sub 2}[BiBr{sub 5}] were synthesized by the slow evaporation method at room temperature and characterized by X-ray diffraction, Raman spectroscopy, optical absorption and photoluminescence measurements. The crystal structure was determined in the monoclinic system with P2{sub 1}/c space group. The structure is built up from BiBr{sub 6} octahedra sharing two cis-bromine atoms and forming infinite [BiBr{sub 5}]{sub n} zig-zag chains surrounded by organic cations. Such a one-dimensional (1D) structure may be regarded as quantum wires system in which the [BiBr{sub 5}]{sub n} inorganic chains act as semiconductor wires and the (C{sub 6}H{sub 14}N) organic cations act as insulator barriers. The cohesion of the structure is achieved by an extensive network of N–H…Br hydrogen bonds. The Raman and Infrared spectra where interpreted by analogy with the homologous materials and by calculation of normal mode frequencies using the density functional theory (DFT) method. The optimized geometry and the calculated frequencies are in good agreement with the experimental data. - Highlights: • A new luminescent organic-inorganic material (C{sub 6}H{sub 14}N){sub 2}BiBr{sub 5} was synthesized. • Vibrational properties were studied by Raman and IR spectroscopy. • The UV–vis spectrum shows three absorption peaks at 3.01, 3.73 and at 4.4 eV. • This compound shows a strong blue emission at 2.71 eV.

  16. Synthesis, crystal structure, thermal analysis and dielectric properties of [(C{sub 4}H{sub 9}){sub 4}N]{sub 3}Bi{sub 2}Cl{sub 9} compound

    Energy Technology Data Exchange (ETDEWEB)

    Trigui, W., E-mail: walatrigui@yahoo.fr; Oueslati, A.; Chaabane, I.; Hlel, F.

    2015-07-15

    A new organic–inorganic tri-tetrabutylammonium nonachlorobibismuthate(III) compound was prepared. It was found to crystallize in the monoclinic system (P2{sub 1}/n space group) with the following lattice parameters: a=11.32(2) Å, b=22.30(3) Å, c=28.53(2) Å and β=96.52(0)°. The [Bi{sub 2}Cl{sub 9}]{sup 3−} anions are surrounded by six [(C{sub 4}H{sub 9})N]{sup +} cations, forming an octahedral configuration. These octahedra are sharing corners in order to provide the tri-dimensional network cohesion. The differential scanning calorimetry reveals four order-disorder reversible phase transitions located at 214, 238, 434 and 477 K. The Raman and infrared spectra confirm the presence of both cationic [(C{sub 4}H{sub 9})N]{sup +} and anionic [Bi{sub 2}Cl{sub 9}]{sup 3−} parts. The dielectric parameters, real and imaginary dielectric permittivity (ε′ and ε″), and dielectric loss tangent (tg δ), were measured in the frequency range of 209 kHz–5 MHz at different temperatures. The variations of dielectric dispersion (ε') and dielectric absorption (ε″) with frequency show a distribution of relaxation times, which is probably related to the change in the dynamical state of the [(C{sub 4}H{sub 9}){sub 4}N]{sup +} cations and the [Bi{sub 2}Cl{sub 9}]{sup 3−} anions. - Graphical abstract: Projection of the atomic arrangement of the [(C{sub 4}H{sub 9}){sub 4}N]{sub 3}Bi{sub 2}Cl{sub 9} compound along the b axis. - Highlights: • The structure of the (TBA){sub 3}Bi{sub 2}Cl{sub 9} compound was solved and reported. • The cristal belongs to the monoclinic system with P2{sub 1}/n space group. • DSC discloses four order–disorder reversible phases transitions. • The temperature-dependent permittivity ε' and ε″ has been investigated.

  17. Asymmetric fission and evaporation of C{sub 60}{sup r+} (r = 2-4) fullerene ions in ion-C{sub 60} collisions: II. Dependence on collisional processes?

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A; Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D [LCAR-IRSAMC, UMR 5589 Universite Paul Sabatier-CNRS, 118 rte de Narbonne, 31062 Toulouse Cedex (France)

    2004-06-28

    In this paper, a quantitative comparison of our experimental data for the asymmetrical fission (AF) and neutral evaporation of the C{sub 60} molecule under proton impact (part I) is made with data published by other authors and often obtained in rather different collisional systems. The comparison with multicharged ions for which more quantitative data are available is focused on. It is demonstrated that size distributions of fragments, averaged fragment sizes, branching ratios between AF and evaporation or between AF channels, are common to all the collisional systems. Differences only appear when the comparison includes the undissociated stable fullerene ion signals.

  18. Ground-based solar absorption measurements of CH{sub 4}, CO, C{sub 2}H{sub 6}, C2H2 and HCN in the tropics

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Anna K.; Warneke, Thorsten; Velasco, Voltaire; Notholt, Justus [Institute of Environmental Physics (IUP), University of Bremen (Germany); Schrems, Otto [Alfred Wegener Institute for Polar and Marine Research (AWI), Bremerhaven (Germany)

    2007-07-01

    The composition of the tropical atmosphere and its change is of significant importance for global climate. Currently large uncertainties in the budgets of many trace gases in the tropics exist, mainly due to a lack of measurements in the tropics. We have performed solar absorption Fourier Transform InfraRed measurements at Paramaribo, Suriname (5.83 N, 55.17 W) during four consecutive dry seasons, starting in autumn 2004. Currently these are the only remote sensing measurements performed in the inner-tropics over a longer time period. In the case of methane these measurements represent the only tropical ground-based remote sensing data of sufficient precision to validate satellite retrievals of CH4. Here we present first results on methane (CH{sub 4}) and trace gases related to biomass burning. Methane retrievals are compared with model simulations, satellite retrievals from SCIAMACHY and in situ data. In addition we investigate the pollution from biomass burning using CO, C{sub 2}H{sub 6}, C{sub 2}H{sub 2} and HCN. Backwardtrajectories and global fire maps were used to identify the origin of the polluted air masses. Correlations between the different gases are analysed and compared to literature data.

  19. Theoretical estimates of the anapole magnetizabilities of C{sub 4}H{sub 4}X{sub 2} cyclic molecules for X=O, S, Se, and Te

    Energy Technology Data Exchange (ETDEWEB)

    Pagola, G. I.; Ferraro, M. B. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, and IFIBA, CONICET, Universidad de Buenos Aires, Ciudad Universitaria, Pab. I, (1428) Buenos Aires (Argentina); Provasi, P. F. [Departamento de Física, Northeastern University, Av. Libertad 5500, W3400 AAS, Corrientes (Argentina); Pelloni, S.; Lazzeretti, P., E-mail: lazzeret@unimo.it [Dipartimento di Chimica, Università degli Studi di Modena e Reggio Emilia, via G. Campi 183, 41100 Modena (Italy)

    2014-09-07

    Calculations have been carried out for C{sub 4}H{sub 4}X{sub 2} cyclic molecules, with X=O, S, Se, and Te, characterized by the presence of magnetic-field induced toroidal electron currents and associated orbital anapole moments. The orbital anapole induced by a static nonuniform magnetic field B, with uniform curl C=∇×B, is rationalized via a second-rank anapole magnetizability tensor a{sub αβ}, defined as minus the second derivative of the second-order interaction energy with respect to the components C{sub α} and B{sub β}. The average anapole magnetizability a{sup ¯} equals −χ{sup ¯}, the pseudoscalar obtained by spatial averaging of the dipole-quadrupole magnetizability χ{sub α,βγ}. It has different sign for D and L enantiomeric systems and can therefore be used for chiral discrimination. Therefore, in an isotropic chiral medium, a homogeneous magnetic field induces an electronic anapole A{sub α}, having the same magnitude, but opposite sign, for two enantiomorphs.

  20. A comparative study of CF{sub 4}/O{sub 2}/Ar and C{sub 4}F{sub 8}/O{sub 2}/Ar plasmas for dry etching applications

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Inwoo [Department of Control and Instrumentation Engineering, Korea University, 2511 Sejong-Ro, Sejong 339-700 (Korea, Republic of); Efremov, Alexander [Department of Electronic Devices & Materials Technology, State University of Chemistry & Technology, 7F. Engels St., 153000 Ivanovo (Russian Federation); Yeom, Geun Young [Department of Advanced Materials Science & Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kwon, Kwang-Ho, E-mail: kwonkh@korea.ac.kr [Department of Control and Instrumentation Engineering, Korea University, 2511 Sejong-Ro, Sejong 339-700 (Korea, Republic of)

    2015-03-31

    The effect of the O{sub 2}/Ar mixing ratio in CF{sub 4}/O{sub 2}/Ar and C{sub 4}F{sub 8}/O{sub 2}/Ar inductively coupled plasmas with a 50% fluorocarbon gas content on plasma parameters and active species densities, which influence dry etching mechanisms, was analyzed. The investigation combined plasma diagnostics using Langmuir probes and zero-dimensional plasma modeling. It was found that, in both gas systems, the substitution of Ar for O{sub 2} results in a similar change in the ion energy flux but causes the opposite behavior for the F atom flux. The mechanisms of these phenomena are discussed with regards to plasma chemistry. - Highlights: • The goal was to conduct a comparative study of CF{sub 4}/O{sub 2}/Ar and C{sub 4}F{sub 8}/O{sub 2}/Ar plasmas. • The focus was on the parameters directly influencing dry etching mechanisms. • Model-based analysis for neutral species was used in this paper.

  1. Early age hydration of calcium sulfoaluminate (synthetic ye'elimite, C{sub 4}A{sub 3}S{sup ¯}) in the presence of gypsum and varying amounts of calcium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Hargis, Craig W. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA (United States); Kirchheim, Ana Paula [Department of Civil Engineering, Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil); Monteiro, Paulo J.M., E-mail: monteiro@ce.berkeley.edu [Department of Civil and Environmental Engineering, University of California, Berkeley, CA (United States); Gartner, Ellis M. [Lafarge Centre de Recherche, St. Quentin Fallavier, Isere (France)

    2013-06-15

    Suspensions of synthetic ye'elimite (C{sub 4}A{sub 3}S{sup ¯}) in a saturated gypsum (CS{sup ¯}H{sub 2}) and calcium hydroxide (CH) solution were examined in-situ in a wet cell by soft X-ray transmission microscopy and ex-situ by scanning electron microscopy. The most voluminous hydration product observed was ettringite. Ettringite commonly displayed acicular, filiform, reticulated, and stellate crystal habits. Additionally, pastes with C{sub 4}A{sub 3}S{sup ¯}, 15% CS{sup ¯}H{sub 2}, and varying amounts of CH were prepared and examined with X-ray diffraction (XRD) and isothermal calorimetry. The XRD experiments showed that increasing CH content caused more solid solution (SO{sub 4}{sup 2−}/OH{sup −}) AFm phases to form at early ages (< 1 d) and more monosulfate to form at later ages (> 1 d). Calorimetry indicated that the increased production of solid solution AFm was accompanied with an increase in the initial (< 30 min) rate of heat evolution, and increasing CH generally reduced the time till the second maximum rate of heat evolution due to the formation of ettringite and monosulfate.

  2. Cascades in model steels: The effect of cementite (Fe{sub 3}C) and Cr{sub 23}C{sub 6} particles on short-term crystal damage

    Energy Technology Data Exchange (ETDEWEB)

    Henriksson, K.O.E.

    2015-06-01

    Ferritic stainless steel can be modeled as an iron matrix containing precipitates of cementite (Fe{sub 3}C) and Cr{sub 23}C{sub 6}. When used in nuclear power production the steels in the vicinity of the core start to accumulate damage due to neutrons. The role of the afore-mentioned carbides in this process is not well understood. In order to clarify the situation bulk cascades created by primary recoils in model steels have been carried out in the present work. Investigated configurations consisted of bulk ferrite containing spherical particles (diameter of 4 nm) of either (1) Fe{sub 3}C or (2) Cr{sub 23}C{sub 6}. Primary recoils were initiated at different distances from the inclusions, with recoil energies varying between 100 eV and 1 keV. Results for the number of point defects such as vacancies and antisites are presented. These findings indicate that defects are also remaining when cascades are started outside the carbide inclusions. The work uses a recently developed Abell–Brenner–Tersoff potential for the Fe–Cr–C system.

  3. Effect of C{sub 2}H{sub 2} flow rate on microstructure and properties of nc–Cu/a–C:H nanocomposite films prepared by filtered cathodic vaccum arc technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Haiqiang; Chen, Yiming; Liao, Bin; Wu, Xianying; Zhang, Huixing [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Zhang, Xu, E-mail: zhangxu@bnu.edu.cn [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)

    2013-07-15

    Nc–Cu/a–C:H nanocomposite films are deposited by filtered cathodic vaccum arc (FCVA) technique using C{sub 2}H{sub 2} as the precursor. The effects of C{sub 2}H{sub 2} flow rate on the microstructure, composition and properties of nc–Cu/a–C:H films have been studied by Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nanoindentation test. In these films, copper nanoparticles (3.5–15 nm) are embedded in the amorphous carbon matrix, which could be confirmed by XRD analysis. Raman spectroscopy and XPS results confirm the decrease of sp{sup 3} content with the increasing copper fraction, which could be a result of more severe thermalization on carbon matrix owing to the presence of copper. The compressive stresses of these films, calculated by Stoney’s equation, are found to be as low as 0.5 Gpa, declining with the increasing copper content. Nanoindentation measurements reveal that the film hardness falls monotonically as the Cu content in the films increases.

  4. A highly sulfur resistant Pt-Sn/{gamma}-Al{sub 2}O{sub 3} catalyst for C{sub 3}H{sub 8}-NO-O{sub 2} reaction under lean conditions

    Energy Technology Data Exchange (ETDEWEB)

    Corro, Grisel; Montiel, Ramon [Instituto de Ciencias, Benemerita Universidad Autonoma de Puebla, 14 Sur 6301, Puebla 72570 (Mexico); Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica, CSIC, Cantoblanco, 28049 Madrid (Spain); Castillo, Salvador; Moran, Marina [Instituto Mexicano del Petroleo, Av. Eje Central No. 152, Mexico 0700, D.F. (Mexico)

    2003-11-10

    The selective catalytic reduction (SCR) of NO with C{sub 3}H{sub 8} was studied over 1% Pt/{gamma}-Al{sub 2}O{sub 3}, and 1% Pt-2% Sn/{gamma}-Al{sub 2}O{sub 3} catalysts. The SO{sub 2} effect on the catalysts activity was examined using pre-sulfated samples of the above catalysts and SO{sub 2}-containing feeds. A high SO{sub 2} tolerance of 1% Pt-2% Sn/{gamma}-Al{sub 2}O{sub 3} pre-sulfated catalyst for C{sub 3}H{sub 8}-NO-O{sub 2} reaction was found. Above 200C, NO was converted mainly into N{sub 2} and N{sub 2}O. Surface analysis of both unsulfated and pre-sulfated catalysts by X-ray photoelectron spectroscopy (XPS) revealed that Sn addition to 1% Pt/{gamma}-Al{sub 2}O{sub 3} prevents Pt particles from sintering during high temperature sulfation process. This fact suggests that a Pt-Sn/{gamma}-Al{sub 2}O{sub 3} catalyst can resist high temperature reactions during automotive exhaust control without losing Pt active area.

  5. State-selective energy and angular resolved detection of neutral species ejected from keV ion bombarded C{sub 6}H{sub 6}/Ag{l_brace}1 1 1{r_brace}

    Energy Technology Data Exchange (ETDEWEB)

    Vandeweert, E.; Meserole, C.A.; Sostarecz, A.; Dou, Y.; Winograd, N. E-mail: nxw@psu.edunxw@psuvm.psu.edu; Postawa, Z

    2000-04-01

    We investigated the desorption of neutral benzene (C{sub 6}H{sub 6}) molecules and silver atoms from C{sub 6}H{sub 6}/Ag{l_brace}1 1 1{r_brace} upon bombardment by 8 keV Ar{sup +} ions. Using state-selective resonant ionization spectroscopy, substrate atoms sputtered in the ground and a high-lying metastable state, and ground-state and vibrationally excited molecules could be probed separately. The silver atom yield, kinetic energy and polar angle distributions were found to be modified upon benzene dosing. From these results, it was inferred that a large fraction of the metastable silver atoms de-excite during collisions with adsorbates. Also the ejection of benzene molecules depends strongly both on the internal energy of the molecules and the degree of coverage of the Ag surface. Up to monolayer thickness, the benzene molecules are mainly ejected during collisions with departing substrate particles. Molecules with higher internal energy leave the surface with a distribution shifted towards higher kinetic energies. At multi-layer coverages, a slow desorption mechanism becomes dominant. It is suggested that only benzene molecules vibrationally excited near the benzene-vacuum interface can survive the ejection process without de-excitation.

  6. Crystallographic and X-ray analysis data of indium(2-isopropyl-8-mercaptoquinolinate)chloride, In(C/sub 9/H/sub 5/(C/sub 3/H/sub 7/)NS)/sub 2/Cl

    Energy Technology Data Exchange (ETDEWEB)

    Pech, L.Ya.; Sturis, A.P.; Ozols, Ya.K.; Apinitis, S.K.; Purmal' , V.N. (AN Latvijskoj SSR, Riga. Inst. Neorganicheskoj Khimii; Rizhskij Politekhnicheskij Inst. (USSR))

    1982-01-01

    The unit cell parameters and space qroup of indium-(2-isopropyl- propyl-8-mercaptoquinolinate) chloride crystals have been determined (Weissenberg's goniometer, Cu-Ksub(..cap alpha..)-radiation). The crystals have been found to exist in two modifications-needles (1) and prismes (2). For 1:a=19.50+-a.01 A; b=16.11+-0.03 A; c=16.23+-0.01 A; ..beta..=100.06 deg +- 0.05 deg; sp. gr. P2/sub 1//a(P2/a, Pa); z=8. For 2:a=23.76+-0.01 A; b=10.80+-0.03 A; c=18.35+-0.01 A; ..beta..=92.28 deg +- 0.03 deg; sp. gr. Csub(2h)sup(6)-C2/c and Csub(s)sup(4)-Cc; z=8. On the optical goniometer the spherical coordinates of the faces and the axonometric projection of indium-(2-isopropyl-8-mercaptoquinolinate) chloride crystals have been determined.

  7. Self-aggregation of ionic liquid 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [C{sub 4}mmim][BF{sub 4}] in aqueous media: A conductometric, volumetric and spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Amalendu, E-mail: palchem21@gmail.com; Pillania, Ankita

    2014-12-10

    Highlights: • Self-aggregation behaviour of [C{sub 4}mmim][BF{sub 4}] has been studied using various techniques. • Thermodynamic parameters showing aggregation is an entropy-driven process. • Volumetric analysis indicates aggregation is influenced by solute–solvent interactions. • {sup 1}H NMR revealed formation of loosely bound aggregates in the system. - Abstract: Aggregation behaviour of ionic liquid (IL), 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, [C{sub 4}mmim][BF{sub 4}] in aqueous media has been studied by electrical conductivity, density and speed of sound measurements across temperature range (288.15–308.15) K. The critical aggregation concentration (cac), the standard Gibb’s free energy of aggregation, ΔG°{sub agg}, adiabatic compressibility, β{sub S} and changes in the adiabatic compressibility upon aggregation, Δβ{sub S,agg} for the IL in aqueous solution have been derived from the experimental data. Further to get the deeper insights into the aggregation process spectroscopic study using {sup 1}H NMR measurements have been carried out. The aggregation behaviour observed from conductance and volumetric approaches has been found to be in good agreement with each other. NMR study revealed the formation of loosely bound ion associates as aggregates in the system upon aggregation.

  8. Probing cis-trans isomerization in the S{sub 1} state of C{sub 2}H{sub 2} via H-atom action and hot band-pumped IR-UV double resonance spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Changala, P. Bryan; Baraban, Joshua H.; Field, Robert W., E-mail: rwfield@mit.edu [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Merer, Anthony J. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada)

    2015-08-28

    We report novel experimental strategies that should prove instrumental in extending the vibrational and rotational assignments of the S{sub 1} state of acetylene, C{sub 2}H{sub 2}, in the region of the cis-trans isomerization barrier. At present, the assignments are essentially complete up to ∼500 cm{sup −1} below the barrier. Two difficulties arise when the assignments are continued to higher energies. One is that predissociation into C{sub 2}H + H sets in roughly 1100 cm{sup −1} below the barrier; the resulting quenching of laser-induced fluorescence (LIF) reduces its value for recording spectra in this region. The other difficulty is that tunneling through the barrier causes a staggering in the K-rotational structure of isomerizing vibrational levels. The assignment of these levels requires data for K values up to at least 3. Given the rotational selection rule K′ − ℓ{sup ′′} = ± 1, such data must be obtained via excited vibrational levels of the ground state with ℓ{sup ′′} > 0. In this paper, high resolution H-atom resonance-enhanced multiphoton ionization spectra are demonstrated to contain predissociated bands which are almost invisible in LIF spectra, while preliminary data using a hyperthermal pulsed nozzle show that ℓ{sup ′′} = 2 states can be selectively populated in a jet, giving access to K′ = 3 states in IR-UV double resonance.

  9. LOW-TEMPERATURE SPECTROSCOPY OF THE {sup 12}C{sub 2}H{sub 2} (υ{sub 1} + υ{sub 3}) BAND IN A HELIUM BUFFER GAS

    Energy Technology Data Exchange (ETDEWEB)

    Santamaria, L.; Sarno, V. Di; Ricciardi, I.; De Rosa, M.; Mosca, S.; Maddaloni, P. [CNR-INO, Istituto Nazionale di Ottica, Via Campi Flegrei 34, I-80078 Pozzuoli (Italy); Santambrogio, G. [CNR-INO, Istituto Nazionale di Ottica, Via N. Carrara 1, I-50019 Sesto Fiorentino (Italy); De Natale, P. [INFN, Istituto Nazionale di Fisica Nucleare, Sez. di Firenze, Via G. Sansone 1, I-50019 Sesto Fiorentino (Italy)

    2015-03-01

    Buffer gas cooling with a {sup 4}He gas is used to perform laser-absorption spectroscopy of the {sup 12}C{sub 2}H{sub 2} (υ{sub 1} + υ{sub 3}) band at cryogenic temperatures. Doppler thermometry is first carried out to extract translational temperatures from the recorded spectra. Then, rotational temperatures down to 20 K are retrieved by fitting the Boltzmann distribution to the relative intensities of several ro-vibrational lines. The potential of our setup to tune the thermal equilibrium between translational and rotational degrees of freedom is also demonstrated. This can be used to reproduce in a controlled way the regime of non-local thermal equilibrium typically encountered in the interstellar medium. The underlying helium-acetylene collisional physics, relevant for modeling planetary atmospheres, is also addressed. In particular, the diffusion time of {sup 12}C{sub 2}H{sub 2} in the buffer cell is measured against the {sup 4}He flux at two separate translational temperatures; the observed behavior is then compared with that predicted by a Monte Carlo simulation, thus providing an estimate for the respective total elastic cross sections: σ{sub el}(100 K) = (4 ± 1) × 10{sup –20} m{sup 2} and σ{sub el}(25 K) = (7 ± 2) × 10{sup –20} m{sup 2}.

  10. 高氯酸碳酰肼盐与硝酸碳酰肼盐系列化合物的晶格能与感度性能关系%Relationship between Lattice Energy and Sensitivity of [M(CHZ)3](NO3)2 and [M(CHZ)3](ClO4)2 (M=Mn, Zn, Ni)

    Institute of Scientific and Technical Information of China (English)

    郑秋雨; 乔小晶; 邵风雷; 张建国; 杨利

    2009-01-01

    为了研究晶格能与感度之间的关系,采用微热量计测定了[M(CHZ)3](NO3)2和[M(CHZ)3](ClO4)2 (M=Mn, Zn, Ni)在去离子水中的溶解焓并计算出它们的标准摩尔溶解焓,根据卡普廷斯基经验公式计算了它们的晶格能,得出配阳离子半径[M(CHZ)3]2+ (M=Mn, Zn, Ni)分别为2.12(A), 1.89(A)和2.70(A);讨论了晶格能与机械感度之间的关系: 相同外阴离子系列中配合物的晶格能越大,感度越小,并且高氯酸碳酰肼盐要比相应的硝酸碳酰肼盐的晶格能低,感度最高的为[Ni(CHZ)3](ClO4)2,最钝感的为[Zn(CHZ)3](NO3)2.%The standard molar enthalpies of series of energetic coordination compounds solution with carbohydrazide as ligand and nitrate or perchlorate as anion in deionized water were measured by a Setaram C80II microcalorimeter at 298.15 K. Based on these values, their lattice energy were calculated through Kapustinkii formula, meanwhile the thermochemistry radius of [M(CHZ)3]2+ (M=Mn, Zn, Ni) was gained. The relationship between lattice energy and impact sensitivity or friction sensitivity was discussed. Results show that the lattice energy of perchlorate are smaller than their corresponding nitrate, thus the perchlorate are more sensitive.

  11. Evaluation of the CR{sub 3}C{sub 2}(NICR) coating deposited on S4400 with the HVOF process for PEM fuel flow plates; Evaluacion del recubrimiento CR{sub 3}C{sub 2}(NICR) depositado sobre S4400 por el proceso HVOF para placas de flujo de celdas de combustible PEM

    Energy Technology Data Exchange (ETDEWEB)

    Rendon Belmonte, M.; Perez Quiroz, J.T. [Instituto Mexicano del Transporte, Queretaro, Queretaro (Mexico)]. E-mail: marielarb17@hotmail.com; Porcayo Calderon, J. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Orozco, G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica S. C., Queretaro, Queretaro (Mexico)

    2009-09-15

    This research studied the behavior of Cr{sub 3}C{sub 2}(NiCr) coating deposited on S4400 with the HVOF (High Velocity Oxygen-Fuel) thermal projection process. Coating was applied after the surface of the plate was prepared with ceramic granulated metal burst according to norm NACE No. 1/ SSPC-SP 5 and cleaned with acetone. The electrolyte used was an H{sub 2}SO{sub 4} 0,5 M + 2 ppm F{sup -} solution at ambient temperature. Mercury sulfate (Hg{sub 2}SO{sub 4}) electrode was used as the reference electrode and the counter electrode used was a graphite bar. To study the electrochemical behavior, polarization curves were generated with a sweep speed of 0.15 mV/s, according to norms ASTM G5 and ASTM G59. Before testing, the Ecorr was measured with a high impedance multimeter (10{sup 6}). The morphological aspect of the coating evaluated was analyzed with SEM (sweep electron microscopy). Based on the obtained icorr values of 1.7*10{sup -4} mA/cm{sup 2} for a period of 576 hours, we can state that this coating meets the criteria for resistance to corrosion required by the DOE (U.S. Department of Energy) for consideration of its use in PEM fuel cell flow plates. [Spanish] En esta investigacion se estudio el comportamiento del recubrimiento Cr{sub 3}C{sub 2}(NiCr), depositado sobre S4400 mediante el proceso de proyeccion termica HVOF (High Velocity Oxygen-Fuel). Previo a la aplicacion del recubrimiento, la placa fue preparada superficialmente mediante rafaga de granalla ceramica de acuerdo con la norma NACE No. 1/ SSPC-SP 5, limpiada con acetona y en esta condicion se procedio a la aplicacion del recubrimiento. El electrolito empleado fue una solucion de H{sub 2}SO{sub 4} 0,5 M + 2 ppm F{sup -} a temperatura ambiente, como electrodo de referencia se empleo un electrodo de sulfato mercuroso (Hg{sub 2}SO{sub 4}) y como contraelectrodo una barra de grafito. Para estudiar el comportamiento electroquimico se realizaron curvas de polarizacion con una velocidad de barrido de 0

  12. Generalized Geology of Australia and New Zealand (geo3cl)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage includes arcs, polygons, and polygon labels that describe the generalized geologic age and rock type of surface outcrops of bedrock of the Australia...

  13. Theoretical studies of the local structure and electron paramagnetic resonance parameters for tetragonal VO{sup 2+} in C{sub 6}H{sub 7}KO{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ping [Chongqing Jiaotong Univ. (China). School of Science; Li, Ling [Sichuan University of Arts and Science, Dazhou (China). Dept. of Maths and Finance-Economics

    2015-07-01

    The optical spectra, electron paramagnetic resonance parameters (i.e., the spin Hamiltonian parameters, including paramagnetic g factors and the hyperfine structure constants A{sub i}) and the local distortion structure for the tetragonal VO{sup 2+} in C{sub 6}H{sub 7}KO{sub 7} are theoretically studied based on the crystal-field theory and three-order perturbation formulas of a 3d{sup 1} centre in tetragonal site. The magnitude of orbital reduction factor, core polarisation constant κ, and local structure parameters are obtained by fitting the calculated optical spectra and electron paramagnetic resonance parameters to the experimental values. The theoretical results are in reasonable agreement with the experimental values.

  14. Chemical shift anisotropies of 1H in H2O(s), H2S(s), and C>6H6(s)

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Larry Michael [Iowa State Univ., Ames, IA (United States)

    1977-10-01

    The proton NMR in powdered samples of H2O(s), H2S(s), and C>6H6(s) have been studied by multiple pulse line narrowing techniques. The resultant spectra provide nuclear magnetic shielding tensors that are (at least approximately) axially symmetric. The anisotropy is 34.2 ± 1.0 ppM for ice, 11.1 ± 1.0 ppM for the highest-temperature phase of solid hydrogen sulfide, and -5.3 ± 0.3 for benzene. Comparisons are made with previous experimental and theoretical work.

  15. Phase coexistence in NaZn{sub 13}-type LaFe{sub 11.4}Al{sub 1.6}C{sub 0.02} compound

    Energy Technology Data Exchange (ETDEWEB)

    Chen Jing [State Key Laboratory of Magnetism, Institute of Physics and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190 (China); Department of Applied Physics, Wuhan University of Science and Technology, Wuhan 430065 (China); Dong Qiaoyan [State Key Laboratory of Magnetism, Institute of Physics and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhang Hongwei [State Key Laboratory of Magnetism, Institute of Physics and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190 (China)], E-mail: hwzhang@aphy.iphy.ac.cn; Zhang Ligang [Department of Applied Physics, Wuhan University of Science and Technology, Wuhan 430065 (China); Sun Jirong; Shen Baogen [State Key Laboratory of Magnetism, Institute of Physics and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2009-10-15

    In NaZn{sub 13}-type LaFe{sub 11.4}Al{sub 1.6}C{sub 0.02} compound, a signature of weak ferromagnetism is observed at {approx}100 K under a low field by ac magnetic-susceptibility and electrical-resistivity measurements, implying the coexistence of ferromagnetic (FM) and antiferromagnetic (AFM) phases. The hysteresis in isofield magnetization curves and large magnetic relaxation demonstrate the metastability of the magnetic state in the AFM-FM transition region. The variations of magnetization with temperature, time and field show distinct step-like behaviors, which is probably attributed to the discontinuous growth of ferromagnetic cluster in antiferromagnetic matrix.

  16. Sm(eta/sup 6/-C/sub 6/Me/sub 6/)(eta/sup 2/-AlCl/sub 4/)/sub 3/: the first structure of a rare earth complex with a neutral. pi. -ligand

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, F.A.; Schwotzer, W.

    1986-07-23

    The authors and others have demonstrated before that one of these intercalators, UCl/sub 4/, can undergo arylation reactions to yield eta/sup 6/-arene complexes and they have structurally characterized such compounds of U(IV) and U(III). In light of the fact that U arene complexes are the only examples of neutral ..pi..-ligands bonded to f-elements, they were wondering whether uranium constitutes a special case and whether an f-orbital contribution was instrumental in the bonding. It was therefore tempting to challenge this synthetic approach with lanthanide metals for which there is no structurally characterized complex with neutral ..pi..-ligands on record. They have chosen a known intercalator of graphite and wish to report here on the first arene complex of a rare earth element, Sm(eta/sup 6/-C/sub 6/Me/sub 6/)(AlCl/sub 4/)/sub 3/-1.5 toluene.

  17. Graphene composite for improvement in the conversion efficiency of flexible poly 3-hexyl-thiophene:[6,6]-phenyl C{sub 71} butyric acid methyl ester polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, A. K., E-mail: akchau@barc.gov.in, E-mail: akc.barc@gmail.com; Gusain, Abhay; Jha, P.; Koiry, S. P.; Saxena, Vibha; Veerender, P.; Aswal, D. K.; Gupta, S. K. [Technical Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India)

    2014-03-31

    The solution of thin graphene-sheets obtained from a simple ultrasonic exfoliation process was found to chemically interact with [6,6]-phenyl C{sub 71} butyric acid methyl ester (PCBM) molecules. The thinner graphene-sheets have significantly altered the positions of highest occupied molecular orbital and lowest unoccupied molecular orbital of PCBM, which is beneficial for the enhancement of the open circuit voltage of the solar cells. Flexible bulk heterojunction solar cells fabricated using poly 3-hexylthiophene (P3HT):PCBM-graphene exhibited a power conversion efficiency of 2.51%, which is a ∼2-fold increase as compared to those fabricated using P3HT:PCBM. Inclusion of graphene-sheets not only improved the open-circuit voltage but also enhanced the short-circuit current density owing to an improved electron transport.

  18. Disodium terephthalate (Na{sub 2}C{sub 8}H{sub 4}O{sub 4}) as high performance anode material for low-cost room-temperature sodium-ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Liang; Hu, Yong-Sheng; Li, Hong; Armand, Michel; Chen, Liquan [Key Laboratory for Renewable Energy, Beijing Key Laboratory for New, Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing (China); Zhao, Junmei [Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing (China); Zhou, Zhibin [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan (China)

    2012-08-15

    In this contribution, a cheap organic material, disodium terephthalate, Na{sub 2}C{sub 8}H{sub 4}O{sub 4}, has been firstly evaluated as a novel anode for room-temperature Na-ion batteries. The material exhibits a high reversible capacity of 250 mAh/g with excellent cycleability. The average Na storage voltage is approximately 0.43 V vs. Na{sup +}/Na. A thin layer of Al{sub 2}O{sub 3} coating on the electrode surface derived from the atomic layer deposition technique is effective in further enhancing Na storage performance. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Multi-fragmentation of C{sub 60} induced by {sup 4}He{sup 2+} impact (E<60 keV/amu) and investigated by a multi-correlation technique

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A.; Moretto-Capelle, P. E-mail: pmc@irsamc.ups-tlse.fr; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A

    2003-05-01

    In this communication, the C{sub 60} multi-fragmentation induced by {sup 4}He{sup 2+} ion impact in the 20-240 keV energy range, is investigated. Using a multi-stop time-of-flight technique, it becomes possible to measure partial spectra corresponding to the simultaneous emission of 2-5 light charged fragments; small charged fragments are found to be accompanied by the emission of at least another one. The fragment size distribution depends on the collisional energy and the multiplicity of emitted charged fragments. It is more peaked on small sizes when the collision velocity or the multiplicity increases. Corresponding relative cross sections are also measured; processes with emission of 2 and 3 charged fragments are always dominant but their relative weights decrease slowly when the collision energy increases.

  20. A Novel Apoptosis Correlated Molecule: Expression and Characterization of Protein Latcripin-1 from Lentinula edodes C>91–3

    Directory of Open Access Journals (Sweden)

    Min Huang

    2012-05-01

    Full Text Available An apoptosis correlated molecule—protein Latcripin-1 of Lentinula edodes C>91-3—was expressed and characterized in Pichia pastoris GS115. The total RNA was obtained from Lentinula edodes C>91–3. According to the transcriptome, the full-length gene of Latcripin-1 was isolated with 3'-Full Rapid Amplification of cDNA Ends (RACE and 5'-Full RACE methods. The full-length gene was inserted into the secretory expression vector pPIC9K. The protein Latcripin-1 was expressed in Pichia pastoris GS115 and analyzed by Sodium Dodecylsulfonate Polyacrylate Gel Electrophoresis (SDS-PAGE and Western blot. The Western blot showed that the protein was expressed successfully. The biological function of protein Latcripin-1 on A549 cells was studied with flow cytometry and the 3-(4,5-Dimethylthiazol-2-yl-2,5-Diphenyl-tetrazolium Bromide (MTT method. The toxic effect of protein Latcripin-1 was detected with the MTT method by co-culturing the characterized protein with chick embryo fibroblasts. The MTT assay results showed that there was a great difference between protein Latcripin-1 groups and the control group (p < 0.05. There was no toxic effect of the characterized protein on chick embryo fibroblasts. The flow cytometry showed that there was a significant difference between the protein groups of interest and the control group according to apoptosis function (p < 0.05. At the same time, cell ultrastructure observed by transmission electron microscopy supported the results of flow cytometry. The work demonstrates that protein Latcripin-1 can induce apoptosis of human lung cancer cells A549 and brings new insights into and advantages to finding anti-tumor proteins.

  1. Catalytic hydrogenation of aromatic hydrocarbons. Stereochemical definition of the catalytic cycle for eta/sup 3/-C/sub 3/H/sub 5/Co(P(OCH/sub 3/)/sub 3/)/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Bleeke, J.R.; Muetterties, E.L.

    1981-02-11

    The eta/sup 3/-C/sub 3/H/sub 5/Co(P(OCH/sub 3/)/sub 3/)/sub 3/-catalyzed hydrogenations with D/sub 2/ of a series of unsaturated organic molecules, including cyclohexenes, cyclohexadienes, and arenes, have been investigated. Complete cis stereoselectivity was observed in the addition of deuterium to the unsaturated ring systems. When alkyl-substituted arenes were reduced with D/sub 2/, the hydrogen atoms in the alkyl chains underwent H-D exchange as long as each successive carbon atom in the chain possessed at least one hydrogen atom. Hence, extensive H-D exchange occurred in n-alkyl side chains while the tert-butyl side chain was deuterium free. When alkyl-substituted arenes were hydrogenated in the presence of olefins such as 1-hexene, a variety of isomeric alkylcyclohexenes and alkenylcyclohexanes were observed. The relative concentrations of these isomeric species provided information about the relative stabilities of the (olefin)cobalt species in the catalytic cycle. Further mechanistic information was obtained from other competitive reactions, i.e., hydrogenation reactions involving equimolar quantities of two different unsaturated molecules. The proposed initiation steps of the catalytic cycle have been revised on the basis of a study of eta/sup 3/-C/sub 8/H/sub 13/Co(P(OCH/sub 3/)/sub 3/)/sub 3/ as a catalyst precursor. The cyclooctenyl-cobalt bond was cleaved by hydrogen early in the reaction, leaving the highly coordinately unsaturated hydride, HCo(P(OCH/sub 3/)/sub 3/)/sub 2/, which is probably the true catalytic species.

  2. NQR Study of Phase Transition and Cationic Motion in 4-NH{sub 2}C{sub 5}H{sub 4}NHBiBr{sub 4}.H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Niki, Haruio, E-mail: niki@sci.u-ryukyu.ac.jp; KINJOU, HIROAKI; FUKUMURA, TAICHI [University of the Ryukyus, Department of Physics, Faculty of Science (Japan); Terao, Hiromitsu; Yoshida, Mami [Tokushima University, Department of Chemistry, Faculty of Integrated Arts and Sciences (Japan); Hashimoto, Masao [Kobe University, Department of Chemistry, Faculty of Science (Japan)

    2004-12-15

    Four {sup 81}Br NQR lines in 4-NH{sub 2}C{sub 5}H{sub 4}NHBiBr{sub 4}.H{sub 2}O were observed in the temperature range between 77 and ca. 380 K; with increasing temperatures the respective sets of higher and lower two resonance lines coalesced into single lines discontinuously at 274 K, showing the occurrence of a first-order type phase transition of this crystal. The transition was confirmed with heat anomaly on a DTA curve. Each higher and lower line of high-temperature phase is assignable to the terminal Br atoms and the bridging ones of one-dimensional poly anions (BiBr{sub 4}{sup -}){sub n} in the crystal structure (C2/c), which was investigated by a X-ray structure analysis at room temperature. The 1/T{sub 1} temperature dependence of {sup 81}Br NQR follows the usual T{sup 2} law in the temperature range between 77 and ca. 140 K, being explained by fluctuation of the EFG at Br nucleus due to lattice vibrations. The T{sub 1} vs. 1/T curve in the temperature range between about 160 and 190 K was describable by the exponential curves, allowing us the estimation of activation energies. These exponential behaviors of T{sub 1} of {sup 81}Br NQR are attributable to the fluctuations caused by the thermal motion of 4-NH{sub 2}C{sub 5}H{sub 4}H{sup +} ions. Echo signals of the {sup 81}Br NQR could not be detected above 190 K owing to poor S/N with very short T{sub 2}.

  3. Rice-ball structures of iron-benzene clusters, Fe{sub 4}-(C{sub 6}H{sub 6}){sub m}, m Less-Than-Or-Slanted-Equal-To 3. A density functional study

    Energy Technology Data Exchange (ETDEWEB)

    Valencia, Israel; Tavizon, Gustavo; Barba-Behrens, Norah [Departamento de Fisica y Quimica Teorica, DEPg. Facultad de Quimica, Universidad Nacional Autonoma de Mexico, C.P. 04510, Mexico D.F. (Mexico); Departamento de Quimica Inorganica, DEPg. Facultad de Quimica, Universidad Nacional Autonoma de Mexico, C.P. 04510, Mexico D.F. (Mexico); Castro, Miguel, E-mail: castro@quetzal.pquim.unam.mx [Departamento de Fisica y Quimica Teorica, DEPg. Facultad de Quimica, Universidad Nacional Autonoma de Mexico, C.P. 04510, Mexico D.F. (Mexico); Departamento de Quimica Inorganica, DEPg. Facultad de Quimica, Universidad Nacional Autonoma de Mexico, C.P. 04510, Mexico D.F. (Mexico)

    2011-11-18

    Graphical abstract: Adsorption of benzene molecules on Fe{sub 4} cluster. Highlights: Black-Right-Pointing-Pointer We studied the interactions of iron clusters with benzene molecules. Black-Right-Pointing-Pointer We have used density functional theory based methods for Fe{sub 4} and benzene. Black-Right-Pointing-Pointer The physicochemical properties were determined for the ground states. Black-Right-Pointing-Pointer The ground state structures for the Fe{sub 4}-benzene species were determined. - Abstract: Geometrical rice-ball structures of the Fe{sub 4} cluster with capped adsorbed benzene molecules for neutral, anion, and cation species, Fe{sub 4}-(C{sub 6}H{sub 6}){sub m} (m Less-Than-Or-Slanted-Equal-To 3), are studied by means of all-electron calculations done with the BPW91 approach of density functional theory jointly with 6-311++G(2d, 2p) basis sets. Electronic properties like ionization energies and electron affinities as well as binding energies are estimated and are in good agreement with recently reported experimental results. The computed IR spectra for these species show vibrational bands near those of the isolated benzene molecule and some forbidden IR modes of this ligand become IR active in Fe{sub 4}-(C{sub 6}H{sub 6}){sub m} (m Less-Than-Or-Slanted-Equal-To 3). The metal-benzene bonding issue was studied through the contour plots of molecular orbitals, showing signatures of metal-carbon bonding, originated from the 3d electrons of Fe{sub 4} and the 2p{pi} electrons of benzene.

  4. Variation of k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} for the small-field dosimetric parameters percentage depth dose, tissue-maximum ratio, and off-axis ratio

    Energy Technology Data Exchange (ETDEWEB)

    Francescon, Paolo, E-mail: paolo.francescon@ulssvicenza.it; Satariano, Ninfa [Department of Radiation Oncology, Ospedale Di Vicenza, Viale Rodolfi, Vicenza 36100 (Italy); Beddar, Sam [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77005 (United States); Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)

    2014-10-15

    Purpose: Evaluate the ability of different dosimeters to correctly measure the dosimetric parameters percentage depth dose (PDD), tissue-maximum ratio (TMR), and off-axis ratio (OAR) in water for small fields. Methods: Monte Carlo (MC) simulations were used to estimate the variation of k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} for several types of microdetectors as a function of depth and distance from the central axis for PDD, TMR, and OAR measurements. The variation of k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} enables one to evaluate the ability of a detector to reproduce the PDD, TMR, and OAR in water and consequently determine whether it is necessary to apply correction factors. The correctness of the simulations was verified by assessing the ratios between the PDDs and OARs of 5- and 25-mm circular collimators used with a linear accelerator measured with two different types of dosimeters (the PTW 60012 diode and PTW PinPoint 31014 microchamber) and the PDDs and the OARs measured with the Exradin W1 plastic scintillator detector (PSD) and comparing those ratios with the corresponding ratios predicted by the MC simulations. Results: MC simulations reproduced results with acceptable accuracy compared to the experimental results; therefore, MC simulations can be used to successfully predict the behavior of different dosimeters in small fields. The Exradin W1 PSD was the only dosimeter that reproduced the PDDs, TMRs, and OARs in water with high accuracy. With the exception of the EDGE diode, the stereotactic diodes reproduced the PDDs and the TMRs in water with a systematic error of less than 2% at depths of up to 25 cm; however, they produced OAR values that were significantly different from those in water, especially in the tail region (lower than 20% in some cases). The microchambers could be used for PDD

  5. Study on the Metastable Phase Equilibria of the Quaternary System Na+//NO3-, CI-, SO42--H2O at 25℃ and 50℃%25℃及50℃下Na+//NO3-,Cl-,SO42--H2O四元体系介稳相平衡研究

    Institute of Scientific and Technical Information of China (English)

    蔺尾燕; 薄文旻; 李惠; 黄雪莉

    2011-01-01

    The metastable liquid-solid phase equilibria of the quaternary system Na+//NO3-, CI-, SO42+-H2O,whieh is the composition of the nitrate deposits in Xinjiang of China, were studied at 25℃ and 50℃ by isothermal evaporation method. Based on the solubility data obtained, the metastable liquid-solid phase diagrams of the system at above two temperatures were plotted respectively. The results show that, in the metastable liquid-solid phase diagrams of the system at different temperatures, there are five univariant curves, two invariant points and four crystallization fields of single salt corresponding separately to NaCl, NaNO3,Na2SO4 and double salt NaNO3·Na2SO4· H2O. One of the invariant points is an incongruent point saturated with NaCl, Na2SO4 and NaNO3·Na2SO4·H2O, and the other is a congruent point saturated with NaCI, NaNO3 and NaNO3·Na2SO4·H2O. Compared the metastable liquid-solid phase diagrams obtained with equilibrium phase diagrams of the same system at 25℃ and 50℃, both the metastable phase diagrams obtained have the same variation trend: the NaCI crystallization regions in the metastable liquid-solid phase diagrams are bigger, the NaNO3·Na2SO4·H2O crystallization regions are smaller and those of NaNO3 do not change obviously.%针对新疆硝酸盐矿组成,采用等温蒸发法分别研究了25℃及50℃下Na+//NO3-,Cl- SO42--H2O四元体系的介稳相平衡、溶解度数据,并根据测得的数据绘制出了相应的介稳相图.结果表明:在25℃及50℃时Na+//NO3-,Cl-,SO42--H2O四元体系介稳相图存在四个单盐结晶区,五条单变量溶解度曲线和两个零变量点.四个单盐结晶区分别对应于NaCl、NaNO3、Na2SO4和NaNO3·Na2SO4·H2O.两个零变量点中,一个为NaCl,Na2SO4和NaNO3·Na2SO4·H2O的三盐不相称共饱点,另一个为NaCl,NaNO3和NaNO3·Na2SO4·H2O的三盐共饱点.与相同温度下平衡相图相比,25℃与50℃下介稳相图具有相同的变化趋势.介稳相图中Na

  6. Conversion efficiency improvement of inverted CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells with room temperature sputtered ZnO by adding the C{sub 60} interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Wei-Chih, E-mail: weilai@mail.ncku.edu.tw; Chen, Peter [Department of Photonics, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Lin, Kun-Wei; Wang, Yuan-Ting [Department of Photonics, National Cheng Kung University, Tainan 70101, Taiwan (China); Guo, Tzung-Fang, E-mail: guotf@mail.ncku.edu.tw [Department of Photonics, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng K