WorldWideScience

Sample records for 3p core levels

  1. A study of angle-resolved photoemission extended fine structure as applied to the Ni 3p, Cu 3s, and Cu 3p core levels of the respective clean (111) surfaces

    Huff, W.R.A.; Moler, E.J.; Kellar, S.A. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    The first non-s initial state angle-resolved photoemission extended fine structure (ARPEFS) study of clean surfaces for the purpose of further understanding the technique is reported. The surface structure sensitivity of ARPEFS applied to clean surfaces and to arbitrary initial states is studied using normal photoemission data taken from the Ni 3p core levels of a Ni(111) single crystal and the Cu 3s and the Cu 3p core-levels of a Cu(111) single crystal. The Fourier transforms of these clean surface data are dominated by backscattering. Unlike the s initial state data, the p initial state data show a peak in the Fourier transform corresponding to in-plane scattering from the six nearest-neighbors to the emitter. Evidence was seen for single-scattering events from in the same plane as the emitters and double-scattering events. Using a newly developed, multiple-scattering calculation program, ARPEFS data from clean surfaces and from p initial states can be modeled to high precision. Although there are many layers of emitters when measuring photoemission from a clean surface, test calculations show that the ARPEFS signal is dominated by photoemission from atoms in the first two crystal layers. Thus, ARPEFS applied to clean surfaces is sensitive to surface reconstruction. The known contraction of the first two Cu(111) layers is confirmed. The best-fit calculation for clean Ni(111) indicates an expansion of the first two layers. To better understand the ARPEFS technique, the authors studied s and non-s initial state photoemission from clean metal surfaces.

  2. A study of angle-resolved photoemission extended fine structure as applied to the Ni 3p, Cu 3s, and Cu 3p core levels of the respective clean (111) surfaces

    The first non-s initial state angle-resolved photoemission extended fine structure (ARPEFS) study of clean surfaces for the purpose of further understanding the technique is reported. The surface structure sensitivity of ARPEFS applied to clean surfaces and to arbitrary initial states is studied using normal photoemission data taken from the Ni 3p core levels of a Ni(111) single crystal and the Cu 3s and the Cu 3p core-levels of a Cu(111) single crystal. The Fourier transforms of these clean surface data are dominated by backscattering. Unlike the s initial state data, the p initial state data show a peak in the Fourier transform corresponding to in-plane scattering from the six nearest-neighbors to the emitter. Evidence was seen for single-scattering events from in the same plane as the emitters and double-scattering events. Using a newly developed, multiple-scattering calculation program, ARPEFS data from clean surfaces and from p initial states can be modeled to high precision. Although there are many layers of emitters when measuring photoemission from a clean surface, test calculations show that the ARPEFS signal is dominated by photoemission from atoms in the first two crystal layers. Thus, ARPEFS applied to clean surfaces is sensitive to surface reconstruction. The known contraction of the first two Cu(111) layers is confirmed. The best-fit calculation for clean Ni(111) indicates an expansion of the first two layers. To better understand the ARPEFS technique, the authors studied s and non-s initial state photoemission from clean metal surfaces

  3. Transition probability values of the 1s22s3p 3P0 level in Be-like ions

    Transition probability values from the 1s22s3p 3P0 level for selected beryllium-like ions, from Z = 5 to 92, are calculated using the multi-configuration Dirac–Fock method including QED corrections, and full correlation up to the 4f subshell in both initial and final levels, for 1s22s3s 3S1, 1s22s2p 3P2 level and 1s22p23P1 decay modes of this level. (paper)

  4. BOREAS Level-3p Landsat TM Imagery: Geocoded and Scaled At-sensor Radiance

    Nickeson, Jaime; Knapp, David; Newcomer, Jeffrey A.; Hall, Forrest G. (Editor); Cihlar, Josef

    2000-01-01

    For BOReal Ecosystem-Atmosphere Study (BOREAS), the level-3p Landsat Thematic Mapper (TM) data were used to supplement the level-3s Landsat TM products. Along with the other remotely sensed images, the Landsat TM images were collected in order to provide spatially extensive information over the primary study areas. This information includes radiant energy, detailed land cover, and biophysical parameter maps such as Fraction of Photosynthetically Active Radiation (FPAR) and Leaf Area Index (LAI). Although very similar to the level-3s Landsat TM products, the level-3p images were processed with ground control information, which improved the accuracy of the geographic coordinates provided. Geographically, the level-3p images cover the BOREAS Northern Study Area (NSA) and Southern Study Area (SSA). Temporally, the four images cover the period of 20-Aug-1988 to 07-Jun-1994. Except for the 07-Jun-1994 image, which contains seven bands, the other three contain only three bands.

  5. Electron impact excitation out of the metastable levels of argon into the 3p54p J = 3 level

    We have measured the direct cross section for electron impact excitation out of the metastable 3p54s[3/2]20 level (1s5 in Paschen's notation) into the 3p54p[5/2]3 level (2p9) of argon from threshold to 800 eV. The direct cross section is 40 x 10-16 cm2 at 10 eV. (author)

  6. Hyperfine Quenching of the $4s4p ^{3}P_{0}$ Level in Zn-like Ions

    Marques, J P; Indelicato, Paul

    2007-01-01

    In this paper, we used the multiconfiguration Dirac-Fock method to compute with high precision the influence of the hyperfine interaction on the $[Ar]3d^{10} 4s4p ^3P_0$ level lifetime in Zn-like ions for stable and some quasi-stable isotopes of nonzero nuclear spin between Z=30 and Z=92. The influence of this interaction on the $[Ar]3d^{10} 4s4p ^3P_1 - [Ar]3d^{10} 4s4p ^3P_0$ separation energy is also calculated for the same ions.

  7. Reduced miR-659-3p Levels Correlate with Progranulin Increase in Hypoxic Conditions: Implications for Frontotemporal Dementia.

    Piscopo, Paola; Grasso, Margherita; Fontana, Francesca; Crestini, Alessio; Puopolo, Maria; Del Vescovo, Valerio; Venerosi, Aldina; Calamandrei, Gemma; Vencken, Sebastian F; Greene, Catherine M; Confaloni, Annamaria; Denti, Michela A

    2016-01-01

    Progranulin (PGRN) is a secreted protein expressed ubiquitously throughout the body, including the brain, where it localizes in neurons and is activated microglia. Loss-of-function mutations in the GRN gene are an important cause of familial frontotemporal lobar degeneration (FTLD). PGRN has a neurotrophic and anti-inflammatory activity, and it is neuroprotective in several injury conditions, such as oxygen or glucose deprivation, oxidative injury, and hypoxic stress. Indeed, we have previously demonstrated that hypoxia induces the up-regulation of GRN transcripts. Several studies have shown microRNAs (miRNAs) involvement in hypoxia. Moreover, in FTLD patients with a genetic variant of GRN (rs5848), the reinforcement of miR-659-3p binding site has been suggested to be a risk factor. Here, we report that miR-659-3p interacts directly with GRN 3'UTR as shown by luciferase assay in HeLa cells and ELISA and Western Blot analysis in HeLa and Kelly cells. Moreover, we demonstrate the physical binding between GRN mRNA and miR-659-3p employing a miRNA capture-affinity technology in SK-N-BE and Kelly cells. In order to study miRNAs involvement in hypoxia-mediated up-regulation of GRN, we evaluated miR-659-3p levels in SK-N-BE cells after 24 h of hypoxic treatment, finding them inversely correlated to GRN transcripts. Furthermore, we analyzed an animal model of asphyxia, finding that GRN mRNA levels increased at post-natal day (pnd) 1 and pnd 4 in rat cortices subjected to asphyxia in comparison to control rats and miR-659-3p decreased at pnd 4 just when GRN reached the highest levels. Our results demonstrate the interaction between miR-659-3p and GRN transcript and the involvement of miR-659-3p in GRN up-regulation mediated by hypoxic/ischemic insults. PMID:27199656

  8. Doping and dimensionality effects on the core-level spectra of layered ruthenates

    Guo, Haizhong; Li, Yi; Urbina, Darwin; Hu, Biao; Jin, Rongying; Liu, Tijiang; Fobes, David; Mao, Zhiqiang; Plummer, E. W.; Zhang, Jiandi

    2010-01-01

    Core-level spectra of the Mn-doped Sr3Ru2O7 and Srn+1RunO3n+1 (n = 1, 2 and 3) crystals are investigated with X-ray photoelectron spectroscopy. Doping of Mn to Sr3Ru2O7 considerably affects the distribution of core-level spectral weight. The satellite of Ru 3d core levels exhibits a substantial change with doping, indicating an enhanced electron localization across the doping- induced metal-insulator transition. However, the Ru 3p core levels remain identical with Mn-doping, thus showing no s...

  9. Measurement of electron-impact excitation into the 3p54p levels of argon using Fourier-transform spectroscopy

    To experimentally determine electron-impact excitation cross sections with the optical method, it is necessary to measure all transitions out of a level (the apparent cross sections), as well as the cascades into the level. In the case of the ten 3p54p levels of argon, the emissions to lower levels lie in the visible and near infrared (660 endash 1150 nm) and are hence observable with a monochromator endash photomultiplier-tube (PMT) system. A Fourier-transform spectrometer (FTS) allows us to measure the previously uninvestigated cascades that lie in the infrared. For the incident electron energy range between onset and 300 eV, we have measured the apparent cross sections with a monochromator-PMT system, and the cascade cross sections with a weak emission FTS system. The magnitude of both the apparent and cascade cross sections increases with target gas pressure due to radiation trapping effects. By subtracting the cascade contributions from the apparent cross sections, we have determined the direct cross sections and verified that they do not vary with pressure in the 0.5 endash 4-mTorr pressure range considered here. copyright 1998 The American Physical Society

  10. Measurement of the photoionization cross-section of the 3p{sup 2}P{sub 1/2,3/2} excited levels of sodium

    Amin, N.; Mahmood, S.; Anwar-ul-Haq, M.; Riaz, M.; Baig, M.A. [Quaid-i-Azam Univ., Atomic and Molecular Physics Lab., Dept. of Physics, Islamabad (Pakistan)

    2006-01-15

    The photoionization cross-section and number density of the 3p{sup 2}P(1/2,3/2) excited levels of sodium have been measured as a function of the laser energy using two-step laser excitation in conjunction with a thermionic diode working in the space charge limited mode. Employing the saturation technique, the cross-sections for the 3p{sup 2}P(1/2) and 3p{sup 2}P(3/2) levels are determined as 2.16 (43) Mb and 3.74 (74) Mb respectively. (authors)

  11. Determination of the effective radiative lifetimes of the 6 3P1 atomic mercury level in low-pressure mercury discharges

    Experiments are described in which low-pressure mercury, mercury-argon and mercury-krypton discharges were irradiated with a dye laser pulse at 365.5 nm, thus exciting mercury atoms from the metastable 6 3P2 level to the 6 3D2 level. The 6 3D2 level decays radiatively to the 6 P levels. By recording the time dependence of the overpopulation in the 6 3P1 and the 6 1P1 level at the fluorescence signals at 254 nm and 185 nm, respectively, the effective radiative lifetime of these levels were determined. The effective radiative lifetime of the 6 3P1 level was measured in the k0R regime 0.1-500. The 6 1P1 lifetime was determined for the following discharge conditions: tube diameter 10-36 mm, mercury density 7.1018-2.1021 m-3, and noble gas pressure 0, 130, 400 Pa

  12. Rhythmic expression of miR-27b-3p targets the clock gene Bmal1 at the posttranscriptional level in the mouse liver.

    Zhang, Wenxiang; Wang, Peng; Chen, Siyu; Zhang, Zhao; Liang, Tingming; Liu, Chang

    2016-06-01

    Circadian clocks orchestrate daily oscillations in mammalian behaviors, physiology, and gene expression. MicroRNAs (miRNAs) play a crucial role in fine-tuning of the circadian system. However, little is known about the direct regulation of the clock genes by specific miRNAs. In this study, we found that miR-27b-3p exhibits rhythmic expression in the metabolic tissues of the mice subjected to constant darkness. MiR-27b-3p's expression is induced in livers of unfed and ob/ob mice. In addition, the oscillation phases of miR-27b-3p can be reversed by restricted feeding, suggesting a role of peripheral clock in regulating its rhythmicity. Bioinformatics analysis indicated that aryl hydrocarbon receptor nuclear translocator-like (also known as Bmal1) may be a direct target of miR-27b-3p. Luciferase reporter assay showed that miR-27b-3p suppressed Bmal1 3' UTR activity in a dose-dependent manner, and mutagenesis of their binding site abolished this suppression. Furthermore, overexpression of miR-27b-3p dose-dependently reduced the protein expression levels of BMAL1 and impaired the endogenous BMAL1 and gluconeogenic protein rhythmicity. Collectively, our results suggest that miR-27b-3p plays an important role in the posttranscriptional regulation of BMAL1 protein in the liver. MiR-27b-3p may serve as a novel node to integrate the circadian clock and energy metabolism.-Zhang, W., Wang, P., Chen, S., Zhang, Z., Liang, T., Liu, C. Rhythmic expression of miR-27b-3p targets the clock gene Bmal1 at the posttranscriptional level in the mouse liver. PMID:26919869

  13. Radiative lifetime of the 3s3p exp 3(exp 5 S sub 2 exp 0) metastable level of P(+)

    Calamai, Anthony G.; Han, Xiaofeng; Parkinson, William H.

    1992-01-01

    The present experimental and theoretical results for the radiative lifetime of the 3s3p exp 3(exp 5 S sub 2 exp 0) metastable level of P(+) encompass an experimental determination of the (exp 5 S sub 2 exp 0) lifetime which represents the first measured lifetime of a low charge-state ion in the Si I sequence. This constitutes a fundamental test of the theoretical methods used to determine transition possibilities for intercombination lines involving this level, and suggests that theoretical techniques used to determine such transition probabilities in low-Z species of the Si I isoelectronic sequence should be reevaluated.

  14. 3p deletion syndrome.

    Kaur, Anupam; Khetarpal, S

    2013-08-01

    3p deletion is a rare cytogenetic finding. Here we describe a 3 months old male with congenital malformations. His karyotype revealed 3p deletion 46,XY,del(3)(p25-pter). The child had flexion deformity of wrist and elbow which has never been reported before. PMID:24036645

  15. A high precision beam-foil meanlife measurement of the 1s3p1P level in HeI

    A beam-foil measurement of the meanlife of the 1s3p1P level in HeI has been made and yields the value 1.7225 +- 0.0046 ns. The measurement was made with standard beam-foil techniques and equipment, but special attention was devoted to minimizing sources of uncertainty. The precision far exceeds that of previous beam-foil meanlife measurements and demonstrates that the beam-foil technique is capable of high precision and is competitive with and more flexible than methods such as resonant laser excitation. (orig.)

  16. Facile aqueous synthesis and electromagnetic properties of novel 3D urchin-like glass/Ni-Ni(3)P/Co(2)P(2)O(7) core/shell/shell composite hollow structures.

    An, Zhenguo; Zhang, Jingjie; Pan, Shunlong

    2010-04-14

    Novel 3D urchin-like glass/Ni-Ni(3)P/Co(2)P(2)O(7) core/shell/shell composite hollow structures are fabricated for the first time by controlled stepwise assembly of granular Ni-Ni(3)P alloy and ribbon-like Co(2)P(2)O(7) nanocrystals on hollow glass spheres in aqueous solutions at mild conditions. It is found that the shell structure and the overall morphology of the products can be tailored by properly tuning the annealing temperature. The as-obtained composite core/shell/shell products possess low density (ca. 1.18 g cm(-3)) and shape-dependent magnetic and microwave absorbing properties, and thus may have some promising applications in the fields of low-density magnetic materials, microwave absorbers, etc. Based on a series of contrast experiments, the probable formation mechanism of the core/shell/shell hierarchical structures is proposed. This work provides an additional strategy to prepare core/shell composite spheres with tailored shell morphology and electromagnetic properties. PMID:20379530

  17. MiR-291b-3p Induces Apoptosis in Liver Cell Line NCTC1469 by Reducing the Level of RNA-binding Protein HuR

    Jun Guo

    2014-03-01

    Full Text Available Background: There is increasing evidence that miRNAs are involved in cellular apoptosis. However, the specific role of miR-291b-3p in apoptosis has not been elucidated. In the present study, we investigated the effect of miR-291b-3p on NCTC1469 cell growth and apoptosis. Methods: Cell viability and apoptosis were examined in NCTC1469 cells transfected with miR-291b-3p mimics, inhibitor miRNA or negative control. Using computational miRNA target prediction databases, HuR was predicted as a target of miR-291b-3p. Luciferase assay, immunofluorescence and western blot were used to further explore the effects of miR-291b-3p on HuR expression. In addition, the effect of HuR on cell apoptosis was evaluated using a HuR-specific siRNA. Results: TNF-α-induced hepatocyte apoptosis was accompanied by enhanced expression of miR-291b-3p, suggesting that miR-291b-3p might contribute to the apoptotic process. Follow-up experiments showed that upregulation of miR-291b-3p decreased cell viability and induced NCTC1469 cell apoptosis. Additionally, similar to the activity of miR-519, which is another member of the same miRNA family, miR-291b-3p suppressed HuR translation through binding to the HuR coding region (CR. We further showed that the downregulation of HuR expression by miR-291b-3p was accompanied by reduced Bcl-2 expression. Moreover, knockdown of HuR also impaired Bcl-2 expression and increased the ratio of Bax/Bcl-2. More significantly, downregulation of miR-291b-3p failed to increase Bcl2 expression in NCTC1469 cells that were co-transfected with siRNA-HuR. Finally, inhibition of miR-291b-3p led to reduced apoptosis, while knockdown of HuR by siRNA promoted apoptosis, even in NCTC1469 cells that were co-transfected with the miR-291b-3p inhibitor. Conclusion: The current data suggested that miR-291b-3p contributed to NCTC1469 cell apoptosis by regulating the expression of HuR, which in turn increased Bcl-2 stability.

  18. Effects of valence-valence, core-valence, and core-core correlations on the fine-structure energy levels in Al-like ions

    This paper reports on multiconfiguration Dirac-Hartree-Fock calculations for both allowed and intercombination transitions and fine structure referring to the levels of a term in highly charged aluminum like ions. Results for fine-structure energy levels, the term splitting, the wavelengths, transition rates, and thereby the branching ratios and lifetimes for the Al-like 3s23p-3s3p2 transitions in the ions Fe XIV-Au LXVII are reported and compared with other theories and experiments, using the codes GRASP2K. Our calculated fine-structure energy levels are in excellent agreement with the experimental results and the experimentally compiled energy values of the National Institute for Standards and Technology wherever available. The calculated values including core-valence correlation are found to be similar and to compare very well with other theoretical and experimental values for medium-Z ions. For higher Z the inclusion of the valence correlation gives results in excellent agreement with those from many-body perturbation theory. We believe that our extensive calculated values can guide experimentalists in identifying the fine-structure levels in their future work. From our radiative decay rates we have also calculated radiative lifetimes of some fine-structure levels. In this calculation we also predict new data for several fine-structure levels where no other theoretical and/or experimental results are available.

  19. Surface core-level shifts for simple metals

    Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

    1994-01-01

    We have performed an ab initio study of the surface core-level binding energy shift (SCLS) for 11 of the simple metals by means of a Green’s-function technique within the tight-binding linear-muffin-tin-orbitals method. Initial- and final-state effects are included within the concept of complete...... screening, whereby a SCLS becomes equivalent to the surface segregation energy of a core-ionized atom, a quantity we obtain by separate bulk and surface impurity calculations. The results are in good agreement with experiment in most of those cases where the data originates from single-crystal measurements....... We discuss the surface shifts of the electrostatic potentials and the band centers in order to trace the microscopic origin of the SCLS in the simple metals and find that the anomalous subsurface core-level shifts in beryllium are caused by charge dipoles, which persist several layers into the bulk...

  20. Titanium core-level spectra in titanium tetrahalide molecules

    Molecular-orbital calculations of TiF4, TiCl4, TiBr4, and TiI4 molecules have been made with use of self-consistent local-density theory with the discrete variational (DV-Xα) method. Core-level excitation energies corresponding to x-ray photoelectron spectroscopy (XPS) measurements are calculated. Spectral peaks associated with metastable final states of the core ionized atom that include relaxation and charge transfer processes are calculated. XPS spectra of Ti core levels in these compounds show that binding energies of both main lines and satellites clearly depend on the ligated anion. The observed systematic behavior of ionization potentials and satellite separation energies for the halide series is calculated with reasonable accuracy. With use of the single-determinant formalism, contributions to the intensity of the main line and satellites are examined

  1. Up-regulation of Serum MiR-130b-3p Level is Associated with Renal Damage in Early Lupus Nephritis

    Wang, Wanpeng; Mou, Shan; Wang, Ling; Zhang, Minfang; Shao, Xinghua; Fang, Wei; Lu, Renhua; Qi, Chaojun; Fan, Zhuping; Cao, Qin; Wang, Qin; Fang, Yan; Ni, Zhaohui

    2015-08-01

    Systemic lupus erythematosus (SLE) is a common but severe autoimmune systemic inflammatory disease. Lupus nephritis (LN) is a serious complication of SLE,affecting up to 70% of SLE patients. Circulating microRNAs (miRNA) are emerging as biomarkers for pathological conditions and play significant roles in intercellular communication. In present research, serum samples from healthy control, early and late stage LN patients were used to analyze the expression profile of miRNAs by microarray. Subsequent study demonstrated that miR-130b-3p in serum of patients with early stage LN were significantly up-regulated when compared with healthy controls. In addition,we have also observed that the expression of a large amount of circulating microRNAs significantly decreased in patients with late stage LN. The further analysis found that the expression of serum miR-130b-3p was positively correlated with 24-hour proteinuria and renal chronicity index in patients with early stage LN.Transfection of renal tubular cellline(HK-2)with miR-130b-3p mimics can promote epithelial-mesenchymal transition (EMT). The opposite effects were observed when transfected with miR-130b-3p inhibitors. MiR-130b-3p negatively regulated ERBB2IP expression by directly targeting the 3‧-UTR of ERBB2IP The circulating miR-130b-3p might serve as a biomarker and play an important role in renal damage in early stage LN patients.

  2. Two-step laser excitation of 4snd 3D1,2,3 and 4sns 3S1 states from the 4s4p 3P levels in zinc

    We present new experimental data on the term energies and quantum defects of the even-parity triplet states of zinc using a two-step laser excitation scheme in conjunction with a thermionic diode ion detector. The first laser was fixed at 32 501.399 cm-1 to populate the 4s4p 3P1 intermediate level. The 4s4p 3P0,2 fine structure components get populated through collisional energy transfer. The second laser was scanned covering the energy region 43 200 to 42 000 cm-1 revealing the highly excited states up to the first ionization limit. Our observations include 4snd 3D2 (14 ≤ n ≤ 55) and 4sns 3S1 (15 ≤ n ≤ 35) Rydberg series excited from the 4s4p 3P1 level. In addition, 4snd 3D3 (13 ≤ n ≤ 49) and 4snd 3D1 (10 ≤ n ≤ 20) series including few members of the 4sns 3S1 series have also been observed from the 4s4p 3P2 and 4s4p 3P0 levels, respectively. The binding energy of 4s4p 3P1 has been determined as 43 267.93 ± 0.02 cm-1, which consequently yields the first ionization potential of zinc as 75 769.35 ± 0.05 cm-1, which is in good agreement with that reported previously

  3. Origin of metallic surface core-level shifts

    Aldén, Magnus; Skriver, Hans Lomholt; Abrikosov, I. A.;

    1995-01-01

    The unique property of the open 4f energy shell in the lanthanide metals is used to show that the initial-state energy shift gives an insufficient description of surface core-level shifts. Instead a treatment, which fully includes the final-state screening, account for the experimentally observed...... surface shifts of the occupied as well as the unoccupied 4f states. The surface energy shift of the initial state corresponds approximately to the average of the shifts for the occupied and unoccupied 4f levels....

  4. Theory of photoemission from the Ni 2p core level

    Photoemission spectra are calculated for the Ni 2p core level within a small-cluster many-body scheme. The interplay between Coulomb, exchange, and spin-orbit interactions is discussed, as well as the role of extra-atomic screening. The spin-dependent transfer of spectral weight, both within and across the levels, is considered. Effects due to circular, linear, and unpolarized excitation are also examined. Local final-state configurations are reported, and a physical interpretation of the various spectral features is given. copyright 1997 The American Physical Society

  5. Determination of shallow core level spectra in selected compound semiconductors

    Core level spectra of the M shells of Ga, Ge, As, and Se and of the L shell of S have been obtained from X-ray photoemission measurements on GaAs, GeSe, and GeS. Broadening contributions from the achromatic source, the analyzer momentum window, and the extrinsic losses experienced by the photoemitted electrons in traversing the solid, as well as satellite lines due to Kα3sub(,)4 emission, are removed by deconvolution of the data with a measured electron backscatter spectrum convoluted with a source function. The results are compared with theory where available. (orig.)

  6. Lattice charge models and core level shifts in disordered alloys

    Underwood, T. L.; Cole, R. J.

    2013-10-01

    Differences in core level binding energies between atoms belonging to the same chemical species can be related to differences in their intra- and extra-atomic charge distributions, and differences in how their core holes are screened. With this in mind, we consider the charge-excess functional model (CEFM) for net atomic charges in alloys (Bruno et al 2003 Phys. Rev. Lett. 91 166401). We begin by deriving the CEFM energy function in order to elucidate the approximations which underpin this model. We thereafter consider the particular case of the CEFM in which the strengths of the ‘local interactions’ within all atoms are the same. We show that for binary alloys the ground state charges of this model can be expressed in terms of charge transfer between all pairs of unlike atoms analogously to the linear charge model (Magri et al 1990 Phys. Rev. B 42 11388). Hence, the model considered is a generalization of the linear charge model for alloys containing more than two chemical species. We then determine the model’s unknown ‘geometric factors’ over a wide range of parameter space. These quantities are linked to the nature of charge screening in the model, and we illustrate that the screening becomes increasingly universal as the strength of the local interactions is increased. We then use the model to derive analytical expressions for various physical quantities, including the Madelung energy and the disorder broadening in the core level binding energies. These expressions are applied to ternary random alloys, for which it is shown that the Madelung energy and magnitude of disorder broadening are maximized at the composition at which the two species with the largest ‘electronegativity difference’ are equal, while the remaining species have a vanishing concentration. This result is somewhat counterintuitive with regards to the disorder broadening since it does not correspond to the composition with the highest entropy. Finally, the model is applied to Cu

  7. Independent Effects of Protein Core Size and Expression on Residue-Level Structure-Evolution Relationships

    Franzosa, Eric A.; Yu Xia

    2012-01-01

    Recently, we demonstrated that yeast protein evolutionary rate at the level of individual amino acid residues scales linearly with degree of solvent accessibility. This residue-level structure-evolution relationship is sensitive to protein core size: surface residues from large-core proteins evolve much faster than those from small-core proteins, while buried residues are equally constrained independent of protein core size. In this work, we investigate the joint effects of protein core size ...

  8. GHRSST Level 3P Global Subskin Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the MetOp-A satellite (GDS version 1)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Level 3 Group for HIgh Resolution Sea Surface Temperature (GHRSST) dataset from the Advanced Very High Resolution Radiometer (AVHRR) on the MetOp-A...

  9. Quasi-static core liquid level depression and long-term core uncovery during a PWR LOCA

    The possibility exists that the core liquid level can be depressed quasi-statically during long-term plant cooldown following a cold-leg-break loss-of-coolant accident in a pressurized-water reactor. Such a level depression can take place if the core steaming rate is almost balanced with the steam condensation rate in the reactor coolant system (RCS). Integral experiments simulating three steam condensation modes in the RCS have shown that quasi-static level depressions can happen and thus have the potential for causing a prolonged uncovery and heatup of the core upper regions

  10. Core liquid level depression in 5% small break LOCAs: an investigation using subscale data

    Core heatup has been shown to be possible, during the course of small break loss-of-coolant accidents (SBLOCAs), even when sufficient inventory is present to fully cover the rods with a two-phase mixture. Such behavior occurs when steam, trapped between the loop seal and the core inventory, moves coolant out of the core barrel region and uncovers the rod upper elevations. The net result is core liquid level depression. Core liquid level depression and subsequent core heatups are investigated using subscale data from the ROSA-IV Program's 1/48-scale Large Scale Test Facility (STF) and the 1/1705-scale Semiscale facility. The depression phenomena and factors which influence the minimum core level are described and illustrated using examples from the data. Analyses conducted using the TRAC-PF1/MOD1 version 12.7 thermal-hydraulic code are also described and summarized

  11. Core liquid level depression due to manometric effect during PWR small break LOCA

    In the previous study, it is reported that the core collapsed liquid level was depressed nearly to the core bottom and the dryout of the core was observed in the early stage of the PWR cold leg small break loss-of-coolant accident (LOCA) experiment. The manometric effect due to the liquid seal formation in the loop seal and the difference of the liquid holdup between the steam generator (SG) upflow-side and downflow-side caused a depression of the core collapsed liquid level. The core liquid level was recovered just after the loop seal was cleared. The bypass between the core side and the downcomer side affects the core liquid depression. Four 5% cold leg break experiments with the different core bypass location, configuration and size were conducted to clarify the bypass effect. When the bypass was relatively small (less than 3% bypass of the initial core flow before the break), the timing of the loop seal clearing delayed with the bypass. When the bypass was relatively large (9.2% of the core flow), the loop seal clearing took place after the break uncovery and the timing was significantly delayed. In general, the smaller minimum core collapsed liquid level was obtained at the earlier timing of loop seal clearing due to the smaller bypass. (author)

  12. Spatial and electronic structure of the Ni3P surface

    To understand the catalytic effect in the Ni-Ni3P for the growth of carbon nanostructures, the structural and electronic properties of Ni3P surface are calculated from first-principles calculations. The calculated surface energies for the (0 0 1)-Ni4P4-terminated surface, the (0 0 1)-Ni8-terminated surface, and the (1 1 0)-Ni8-terminated surface show that the (0 0 1)-Ni4P4-terminated surface is energetically more stable within the allowed range of the chemical potential of P. Through the analysis of the partial density of states of Ni and P atoms in surface and bulk states, respectively, it is further found that due to the bond contractions of the surface layer, the core-level shifts of P atoms in the (0 0 1)-Ni4P4-terminated surface make P atoms in the Ni3P particles act as a catalyst. Finally, the obtained results of the work function show that the (0 0 1)-Ni4P4-terminated surface has the largest work function when compared with the other two studied surfaces.

  13. Integration into the South African Core Economy: Household Level Covariates

    Sten Dieden

    2003-01-01

    The aim of this paper is to further improve the understanding of income generation among the formerly underprivileged and often impoverished majority of households in South Africa. This study uses household survey data for the analysis of households' integration into the South African core economy. The emerging picture of household income generation is one that disputes common perceptions of the multitude of means by which African households are assumed to generate their income. The majority ...

  14. Alkaline Earth Core Level Photoemission Spectroscopy of High-Temperature Superconductors

    Vasquez, R.

    1993-01-01

    This paper examines photoemission measurements of the alkaline Earth core levels of high-temperature superconductors and related materials, models that seek to explain the large negative shifts observed relative to the corresponding alkaline Earth metals, and the effect of lattice site disorder on the core level spectra and the presence or absence of intrinsic surface peaks.

  15. Evidence of the nature of core-level photoemission satellites using angle-resolved photoemission extended fine structure

    Moler, E.J.; Kellar, S.A.; Huff, W.R.A. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    The authors present a unique method of experimentally determining the angular momentum and intrinsic/extrinsic origin of core-level photoemission satellites by examining the satellite diffraction pattern in the Angle Resolved Photoemission Extended Fine Structure (ARPEFS) mode. They show for the first time that satellite peaks not associated with chemically differentiated atomic species display an ARPEFS intensity oscillation. They present ARPEFS data for the carbon 1s from ({radical}3x{radical}3)R30 CO/Cu(111) and p2mg(2xl)CO/Ni(110), nitrogen 1s from c(2x2) N{sub 2}/Ni(100), cobalt 1s from p(1x1)Co/Cu(100), and nickel 3p from clean nickel (111). The satellite peaks and tails of the Doniach-Sunjic line shapes in all cases exhibit ARPEFS curves which indicate an angular momentum identical to the main peak and are of an intrinsic nature.

  16. Energy-band alignment of II-VI/Zn3P2 heterojunctions from x-ray photoemission spectroscopy

    Watson, Graeme

    2013-01-01

    PUBLISHED The energy-band alignments for zb-ZnSe(001)/ a -Zn 3 P 2 (001), w-CdS(0001)/ a -Zn 3 P 2 (001), and w-ZnO(0001)/ a -Zn 3 P 2 (001) heterojunctions have been determined using high-resolution x-ray photoelectron spectroscopy via the Kraut method. Ab initio hybrid density functional theory calculations of the valence-band density of states were used to determine the energy differences between the core level and ...

  17. An investigation of core liquid level depression in small break loss-of-coolant accidents

    Core liquid level depression can result in partial core dryout and heatup early in a small break loss-of-coolant accident (SBLOCA) transient. Such behavior occurs when steam, trapped in the upper regions of the reactor primary system (between the loop seal and the core inventory), moves coolant out of the core region and uncovers the rod upper elevations. The net result is core liquid level depression. Core liquid level depression and subsequent core heatups are investigated using subscale data from the ROSA-IV Program's 1/48-scale Large Scale Test Facility (LSTF) and the 1/1705-scale Semiscale facility. Both facilities are Westinghouse-type, four-loop, pressurized water reactor simulators. The depression phenomena and factors which influence the minimum core level are described and illustrated using examples from the data. Analyses of the subject experiments, conducted using the TRAC-PF1/MOD1 (Version 12.7) thermal-hydraulic code, are also described and summarized. Finally, the response of a typical Westinghouse four-loop plant (RESAR-3S) was calculated to qualitatively study coal liquid level depression in a full-scale system. 31 refs., 37 figs., 6 tabs

  18. Ab initio surface core-level shifts and surface segregation energies

    Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

    1993-01-01

    We have calculated the surface core-level energy shifts of the 4d and 5d transition metals by means of local-density theory and a Green’s-function technique based on the linear muffin-tin orbitals method. Final-state effects are included by treating the core-ionized atom as an impurity located in...

  19. Deep layer-resolved core-level shifts in the beryllium surface

    Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

    1993-01-01

    Core-level energy shifts for the beryllium surface region are calculated by means of a Green’s function technique within the tight-binding linear muffin-tin orbitals method. Both initial- and final-state effects in the core-ionization process are fully accounted for. Anomalously large energy shifts...

  20. Core-Substituted Naphthalenediimides: LUMO Levels Revisited, in Comparison with Preylenediimides with Sulfur Redox Switches in the Core.

    Miros, François N; Matile, Stefan

    2016-06-01

    Core-substituted naphthalenediimides (NDIs) attract increasing attention to bind, transport, and transform electrons, anions, anionic intermediates, and anionic transition states, and to shine as most colorful rainbow fluorophores. The energy level of their lowest unoccupied molecular orbital (LUMO) is decisive for many of these applications. Here, differential pulse voltammetry (DPV) measurements for a consistent series of NDIs are reported to extract exact LUMO levels under identical conditions. The influence of primary and secondary substituents in the core and on the primary imides is compared with general trends for the reliable prediction of LUMO levels in functional systems. Emphasis is on sulfur redox switches in the NDI core because of their frequent use as isostructural probes for π acidity. The same sulfur redox chemistry is expanded to perylenediimides (PDIs), and LUMO engineering is discussed in a broader context, including also fullerenes, aminonaphthalimides (ANIs), and aminoperyleneimides (APIs). The result is a comprehensive reference table that graphically maps out the LUMO space covered by the leading families of electronaccepting aromatics. This graphical summary of general trends in the π-acidic space is expected to be both inspiring and quite useful in practice. PMID:27551658

  1. The optimized algorithm for the microscopic depletion model in the COCAGNE core code a 2-level core partitioning approach

    EDF/R and D is developing a new calculation scheme based on the transport-Simplified Pn (SPn) approach. The lattice code used is the deterministic code APOLLO2, developed at CEA with the support of EDF and AREVA-NP. The core code is the code COCAGNE, developed at EDF R and D. The latter can take advantage of a microscopic depletion solver which improves the treatment of spectral history effects. The accuracy of this model has been proven to be very useful for industrial uses but until now, being very time consuming as well as memory greedy, this model could not be used in production and needed to be re-written from the ground with speed and memory constraints in mind. This paper introduces the new methodology, a 2-levels core partitioning paradigm. Theses partitions, based on physics considerations, are also well suited for modern multi-core CPU architecture, and parallelizing in shared memory shows good speedup. Compared to the previous version, a total speedup of around 100 has been obtained: roughly 20 due to the algorithm and 5 due to the parallelization on a 8 cores chip. These results have been obtained on a machine similar to those that will be used in production. (author)

  2. A first-principles core-level XPS study on the boron impurities in germanium crystal

    Yamauchi, Jun [Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan); Yoshimoto, Yoshihide [Department of Applied Mathematics and Physics, Graduate School of Engineering, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8552 (Japan); Suwa, Yuji [Central Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-0395 (Japan)

    2013-12-04

    We systematically investigated the x-ray photoelectron spectroscopy (XPS) core-level shifts and formation energies of boron defects in germanium crystals and compared the results to those in silicon crystals. Both for XPS core-level shifts and formation energies, relationship between defects in Si and Ge is roughly linear. From the similarity in the formation energy, it is expected that the exotic clusters like icosahedral B12 exist in Ge as well as in Si.

  3. Surface core-level shifts for Ge(100)-(2 x 1)

    Miller, T.; Rosenwinkel, E.; Chiang, T.C.

    1983-01-01

    Using surface-sensitive photoemission techniques, Ge 3d core-level binding energies for surface atoms of Ge(100)-(2 x 1) are found to be smaller than the bulk values by 0.41 eV. The surface atoms with shifted core-level binding energies correspond to one full (100) atomic layer. A surface core-exciton resonance is observed in the partial-yield measurements. The empty surface state involved in this excitonic transition, without binding-energy correction, is located at the valence-band maximum. 14 references, 2 figures, 1 table.

  4. Surface core-level shifts for Ge(100)-(2 x 1)

    Miller, T.; Rosenwinkel, E.; Chiang, T.C.

    1983-01-01

    Using surface-sensitive photoemission techniques, Ge 3d core-level binding energies for surface atoms of Ge(100)-(2 x 1) are found to be smaller than the bulk values by 0.41 eV. The surface atoms with shifted core-level binding energies correspond to one full (100) atomic layer. A surface core-exciton resonance is observed in the partial-yield measurements. The empty surface state involved in this excitonic transition, without binding-energy correction, is located at the valence-band maximum.

  5. Core liquid level depression due to manometric effect during PWR small break LOCA

    The 10, 5 and 2.5 % cold leg break loss-of-coolant accident experiments were conducted by using the Large Scale Test Facility (LSTF) of the Rig of Safety Assessment (ROSA)-IV program. In the early stage of the 5 % break experiment, the core collapsed liquid level was depressed nearly to the core bottom and the dryout of the core was observed. However, the core liquid level depression without the core dryout was observed in the 10 and 2.5 % break experiments. In the three break experiments, the core liquid levels were recovered just after the loop seal clearing. The manometric effect due to the liquid seal formation in the loop seal and the liquid holdup in the steam generator (SG) U-tubes upflow-side caused a depression of the core collapsed liquid level. The liquid holdup in the U-tubes upflow-side was observed after the termination of the two-phase circulation due to the phase separation at the U-tubes top. The counter current flow limiting (CCFL) and the condensation of steam was considered to be the main reason for the liquid holdup. In the 10, 5 and 2.5 % break experiments, the termination of the two-phase circulation and the loop seal clearing were observed approximately at 40 ∼ 60 % and 30 % mass inventory in the primary system, respectively. (author)

  6. $^3P_2$ Superfluids Are Topological

    Mizushima, Takeshi

    2016-01-01

    We clarify the topology of the $^3P_2$ superfluidity which is expected to be realized in the cores of neutron stars and cubic odd-parity superconductors. The phase diagram includes the unitary uniaxial/biaxial nematic phases and nonunitary ferromagnetic and cyclic phases. We here show that the low-energy structures of all the phases are governed by different types of topologically protected gapless fermionic excitations: Surface Majorana fermions in nematic phases, single itinerant Majorana fermion in the ferromagnetic phase, and a quartet of itinerant Majorana fermions in the cyclic phase. Using the superfluid Fermi liquid theory, we also demonstrate that dihedral-two and -four biaxial nematic phases are thermodynamically favored in the weak coupling limit under a magnetic field. The mass acquisition of surface Majorana fermions in nematic phases is subject to symmetry.

  7. Out-of-Core Computations of High-Resolution Level Sets by Means of Code Transformation

    Christensen, Brian Bunch; Nielsen, Michael Bang; Museth, Ken

    2012-01-01

    We propose a storage efficient, fast and parallelizable out-of-core framework for streaming computations of high resolution level sets. The fundamental techniques are skewing and tiling transformations of streamed level set computations which allow for the combination of interface propagation, re...... level set computations are now CPU bound and consequently the overall performance is unaffected by disk latency and bandwidth limitations. We demonstrate this with several benchmark tests that show sustained out-of-core throughputs close to that of in-core level set simulations.......-normalization and narrow-band rebuild into a single pass over the data stored on disk. When combined with a new data layout on disk, this improves the overall performance when compared to previous streaming level set frameworks that require multiple passes over the data for each time-step. As a result, streaming...

  8. Probing core-electron orbitals by scanning transmission electron microscopy and measuring the delocalization of core-level excitations

    Jeong, Jong Seok; Odlyzko, Michael L.; Xu, Peng; Jalan, Bharat; Mkhoyan, K. Andre

    2016-04-01

    By recording low-noise energy-dispersive x-ray spectroscopy maps from crystalline specimens using aberration-corrected scanning transmission electron microscopy, it is possible to probe core-level electron orbitals in real space. Both the 1 s and 2 p orbitals of Sr and Ti atoms in SrTi O3 are probed, and their projected excitation potentials are determined. This paper also demonstrates experimental measurement of the electronic excitation impact parameter and the delocalization of an excitation due to Coulombic beam-orbital interaction.

  9. Detection of subsurface core-level shifts in Si 2p core-level photoemission from Si(111)-(1x1):As

    Paggel, J.J. [Philipps-Universitaet Marburg (Germany); Hasselblatt, M.; Horn, K. [Fritz-Haber Institut der Max-Planck-Gesellschraft, Berlin (Germany)] [and others

    1997-04-01

    The (7 x 7) reconstruction of the Si(111) surface arises from a lowering energy through the reduction of the number of dangling bonds. This reconstruction can be removed by the adsorption of atoms such as hydrogen which saturate the dangling bonds, or by the incorporation of atoms, such as arsenic which, because of the additional electron it possesses, can form three bonds and a nonreactive lone pair orbital from the remaining two electrons. Core and valence level photoemission and ion scattering data have shown that the As atoms replace the top silicon atoms. Previous core level spectra were interpreted in terms of a bulk and a single surface doublet. The authors present results demonstrate that the core level spectrum contains two more lines. The authors assign these to subsurface silicon layers which also experience changes in the charge distribution when a silicon atom is replaced by an arsenic atom. Subsurface core level shifts are not unexpected since the modifications of the electronic structure and/or of photohole screening are likely to decay into the bulk and not just to affect the top-most substrate atoms. The detection of subsurface components suggests that the adsorption of arsenic leads to charge flow also in the second double layer of the Si(111) surface. In view of the difference in atomic radius between As and Si, it was suggested that the (1 x 1): As surface is strained. The presence of charge rearrangement up to the second double layer implies that the atomic coordinates also exhibit deviations from their ideal Si(111) counterparts, which might be detected through a LEED I/V or photoelectron diffraction analysis.

  10. Thermal-hydraulic mechanisms of core liquid level depression and recovery during small break LOCA experiment

    A 5% cold leg break loss-of-coolant accident experiment was conducted by using the Large Scale Test Facility (LSTF) of the Rig of Safety Assessment (ROSA)-IV program. In the early stage of experiment, the core collapsed liquid level was depressed to the bottom of the simulated core and the dryout of the core was observed. The maximum superheat of heater rod surface temperature was about 100 K at the middle of core and the entire core was quenched just after the loop seal clearing. The manometric effect due to the liquid seal formation in the loop seal and the liquid holdup in the steam generator (SG) U-tubes upflow-side caused a depression of the core collapsed liquid level in spite of the coolant injection from the emergency core cooling system (ECCS). The liquid holdup in the U-tubes upflow-side was observed after the termination of the two-phase circulation due to the phase separation at the U-tubes top

  11. Core-level and valence-band photoemission study of granular platinum films

    Photoemission and resistivity measurements have been made on Pt clusters imbedded in an amorphous silicon dioxide matrix. No significant changes in the Pt 4f/sub 7/2/ or 5d/sub 5/2/ core-level shifts or in the density of states per Pt atom at the Fermi level are seen at the percolation threshold. Most of the Pt 4f/sub 7/2/ core-level shift can be explained as a Coulomb effect due to finite cluster size. We speculate that because of the unusually large core-level shifts there may also be charge transfer from the Pt clusters to the silica matrix

  12. Reactor core water level monitor system and startup for CPR1000 nuclear power plant

    Reactor core water level monitor system is an important system used in CPR1000 nuclear power plant for monitoring the water level of reactor core after LOCA accident. The level measured by this system is used directly in the accident operation procedure. The principle of the measurement and the component of the system were introduced. According to the startup work of the first project for CPR1000, the goal for the first startup of this system relying on domestic engineering team was achieved. (authors)

  13. CORE

    Krigslund, Jeppe; Hansen, Jonas; Hundebøll, Martin;

    2013-01-01

    different flows. Instead of maintaining these approaches separate, we propose a protocol (CORE) that brings together these coding mechanisms. Our protocol uses random linear network coding (RLNC) for intra- session coding but allows nodes in the network to setup inter- session coding regions where flows...... increase the benefits of XORing by exploiting the underlying RLNC structure of individual flows. This goes beyond providing additional reliability to each individual session and beyond exploiting coding opportunistically. Our numerical results show that CORE outperforms both forwarding and COPE......-like schemes in general. More importantly, we show gains of up to 4 fold over COPE-like schemes in terms of transmissions per packet in one of the investigated topologies....

  14. Maximum core loading of Kartini Reactor at 250 kW of power level

    Maximum core loading of Kartini Reactor at 250 kW of power level. Reevaluation of the safety aspect of Kartini Reactor is currently being performed, for the purpose of increasing the nominal power from 100 to 250 kW. The results of the evaluations will be used to verify the feasibility of the reactor to operate at the proposed power level. One of the important safety parameters which needs to be reevaluated is related to the shutdown capability of the available control rods, which is normally indicated through the parameter of available Shudown Margin (SDM), which is a function of both power level and Core Loading. This paper presents the methodology and the result of determining the Maximum Core Loading of Kartini Reactor at power level of 250 kW. The result indicates that the maximum core loading of Kartini reactor, for 250 kW of Nominal Power is 82 fuel elements, associated with 3.8 $ of available core excess. It is concluded that the negative reactivity of the available control rods is still sufficient to compensate the amount of reactivity produced by the addition of 11 new fuel elements over the minimum requirement for operation at 250 kW of power level

  15. Femtomagnetism in graphene induced by core level excitation of organic adsorbates

    Ravikumar, Abhilash; Baby, Anu; Lin, He; Brivio, Gian Paolo; Fratesi, Guido

    2016-01-01

    We predict the induction or suppression of magnetism in the valence shell of physisorbed and chemisorbed organic molecules on graphene occurring on the femtosecond time scale as a result of core level excitations. For physisorbed molecules, where the interaction with graphene is dominated by van der Waals forces and the system is non-magnetic in the ground state, numerical simulations based on density functional theory show that the valence electrons relax towards a spin polarized configuration upon excitation of a core-level electron. The magnetism depends on efficient electron transfer from graphene on the femtosecond time scale. On the other hand, when graphene is covalently functionalized, the system is magnetic in the ground state showing two spin dependent mid gap states localized around the adsorption site. At variance with the physisorbed case upon core-level excitation, the LUMO of the molecule and the mid gap states of graphene hybridize and the relaxed valence shell is not magnetic anymore. PMID:27089847

  16. High resolution core level spectroscopy of hydrogen-terminated (1 0 0) diamond.

    Schenk, A K; Rietwyk, K J; Tadich, A; Stacey, A; Ley, L; Pakes, C I

    2016-08-01

    Synchrotron-based photoelectron spectroscopy experiments are presented that address a long standing inconsistency in the treatment of the C1s core level of hydrogen terminated (1 0 0) diamond. Through a comparison of surface and bulk sensitive measurements we show that there is a surface related core level component to lower binding energy of the bulk diamond component; this component has a chemical shift of [Formula: see text] eV which has been attributed to carbon atoms which are part of the hydrogen termination. Additionally, our results indicate that the asymmetry of the hydrogen terminated (1 0 0) diamond C1s core level is an intrinsic aspect of the bulk diamond peak which we have attributed to sub-surface carbon layers. PMID:27299369

  17. Spin polarization and magnetic dichroism in core-level photoemission from ferromagnets

    Menchero, J G [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1997-05-01

    In this thesis we present a theoretical investigation of angle- and spin-resolved core-level photoemission from ferromagnetic Fe and Ni. We also consider magneto-dichroic effects due to reversal of the photon helicity or reversal of the sample magnetization direction. In chapter 1, we provide a brief outline of the history of photoemission, and show how it has played an important role in the development of modern physics. We then review the basic elements of the theory of core-level photoemission, and discuss the validity of the some of the commonly-used approximations. In chapter 2, we present a one-electron theory to calculate spin- and angle-resolved photoemission spectra for an arbitrary photon polarization. The Hamiltonian includes both spin-orbit and exchange interactions. As test cases for the theory, we calculate the spin polarization and magnetic dichroism for the Fe 2p core level, and find that agreement with experiment is very good.

  18. Photoemission with high-order harmonics: A tool for time-resolved core-level spectroscopy

    Christensen, Bjarke Holl; Raarup, Merete Krog; Balling, Peter

    2010-01-01

    A setup for femtosecond time-resolved photoelectron spectroscopy of solid surfaces is presented. The photon energies for core-level spectroscopy experiments are created by high-order harmonic generation from infrared 120-femtosecond laser pulses focused in a Ne gas jet. The present experimental r...... from the sample are collected by a large-solid-angle time-of-flight electron spectrometer based on a parabolic-grid reflector. Results from experiments probing the Bi 5d core-levels are presented, and the results of preliminary pump-probe experiments are described....

  19. Modeling Shallow Core-Level Transitions in the Reflectance Spectra of Gallium-Containing Semiconductors

    Stoute, Nicholas; Aspnes, David

    2012-02-01

    The electronic structure of covalent materials is typically approached by band theory. However, shallow core level transitions may be better modeled by an atomic-scale approach. We investigate shallow d-core level reflectance spectra in terms of a local atomic-multiplet theory, a novel application of a theory typically used for higher-energy transitions on more ionic type material systems. We examine specifically structure in reflectance spectra of GaP, GaAs, GaSb, GaSe, and GaAs1-xPx due to transitions that originate from Ga3d core levels and occur in the 20 to 25 eV range. We model these spectra as a Ga^+3 closed-shell ion whose transitions are influenced by perturbations on 3d hole-4p electron final states. These are specifically spin-orbit effects on the hole and electron, and a crystal-field effect on the hole, attributed to surrounding bond charges and positive ligand anions. Empirical radial-strength parameters were obtained by least-squares fitting. General trends with respect to anion electronegativity are consistent with expectations. In addition to the spin-orbit interaction, crystal-field effects play a significant role in breaking the degeneracy of the d levels, and consequently are necessary to understand shallow 3d core level spectra.

  20. New determination of the core-level life-time broadenings in mercury

    Martensson, Nils, E-mail: nils.martensson@fysik.uu.se; Svensson, Svante

    2015-07-15

    Highlights: • We report core-level life-time widths for mercury in the gas phase. • Photoelectron spectra for the 4p, 4d, 4f and 5p levels are analyzed. • A Coster–Kronig like CI effect is observed for the 4d{sub 3/2} level. - Abstract: Previously recorded and published photoelectron spectroscopic data for mercury in the gas phase has been reanalyzed. The life-time broadenings have been determined for a large number of core levels. It is then seen that a recent detailed derivation of core-level line-widths based on X-ray emission spectroscopy give life-time widths that are generally too large. The 4d{sub 3/2}4d{sub 5/2}nd Coster–Kronig (CK) transition is also discussed. We find that the additional broadening of the 4d{sub 3/2} level for mercury metal is indeed due to a CK decay, in contrast to recent claims. In atomic mercury, however, the CK process in energetically forbidden. In spite of this we find that the 4d{sub 3/2} level is broadened also in this case. We propose that this is due to a mixing between the 4d{sub 3/2} hole state and discrete 4d{sub 5/2}nd states.

  1. New determination of the core-level life-time broadenings in mercury

    Highlights: • We report core-level life-time widths for mercury in the gas phase. • Photoelectron spectra for the 4p, 4d, 4f and 5p levels are analyzed. • A Coster–Kronig like CI effect is observed for the 4d3/2 level. - Abstract: Previously recorded and published photoelectron spectroscopic data for mercury in the gas phase has been reanalyzed. The life-time broadenings have been determined for a large number of core levels. It is then seen that a recent detailed derivation of core-level line-widths based on X-ray emission spectroscopy give life-time widths that are generally too large. The 4d3/24d5/2nd Coster–Kronig (CK) transition is also discussed. We find that the additional broadening of the 4d3/2 level for mercury metal is indeed due to a CK decay, in contrast to recent claims. In atomic mercury, however, the CK process in energetically forbidden. In spite of this we find that the 4d3/2 level is broadened also in this case. We propose that this is due to a mixing between the 4d3/2 hole state and discrete 4d5/2nd states

  2. French--Core Program. Senior Level. Youth Education: Teaching Guide No. 22.

    Nova Scotia Dept. of Education, Halifax.

    The curriculum guidelines for the high school level of Nova Scotia's core French program, intended for students planning to attend college or certain other postsecondary programs, are presented. The four basic language skills (listening, speaking, reading, and writing) are integrated into all phases of classroom activity and the ability to…

  3. Core level shifts in Cu-Pd alloys as a function of bulk composition and structure

    Boes, Jacob R.; Kondratyuk, Peter; Yin, Chunrong; Miller, James B.; Gellman, Andrew J.; Kitchin, John R.

    2015-10-01

    CuPd alloys are important materials in hydrogen purification, where they are used as dense Pd-based separation membranes. Cu is added to impart sulfur tolerance and improved mechanical properties. At intermediate compositions and T < 873 K, a BCC alloy (B2) phase occurs, which has superior separation characteristics to those of the FCC phases that form at high Cu and high Pd compositions. Identifying the composition and temperature window where the B2 phase forms is a critical need to enable the design of improved alloys. A composition spread alloy film of Cu and Pd was synthesized. The film was characterized by electron back scatter diffraction and X-ray photoelectron spectroscopy, providing the core level shifts as a function of bulk composition and bulk structure. An anomalous deviation in the Cu core level shift was observed in the composition range 0.33 < xPd < 0.55 over which the B2 phase occurs. Density functional theory calculations were used to simulate core level shifts in the FCC and B2 alloy structures. They suggest that the anomalous deviation in core level shift is due to formation of the ordered B2 phase in this composition range.

  4. Direct evidence for the nature of core-level photoemission satellites using angle-resolved photoemission extended fine structure

    Photoemission satellites from several systems have been found to exhibit exactly the same angle-resolved photoemission extended fine structure (ARPEFS) as found in the main peaks, when referred to the equivalent photoelectron wave number k for their own photoelectrons. This provides a direct and powerful method for experimentally determining the angular momentum parameters and the intrinsic/extrinsic nature of core-level photoemission satellites. We present ARPEFS satellite data for nitrogen 1s line in c(2x2)N2/Ni(100), the nickel 3p line in clean nickel (111), the carbon 1s lines in (√(3)x√(3))R30 CO/Cu(111) and p2mg(2x1)CO/Ni(110), and the cobalt 1s line in p(1x1) Co/Cu(100). For the last two cases the open-quotes satelliteclose quotes structure is actually the low-energy tail of a Doniach-Sunjic line shape. The satellite peaks and the tails of the Doniach-Sunjic line shapes exhibit ARPEFS curves that in all cases except one indicate angular-momentum parameters identical to the main peak and an intrinsic nature. copyright 1997 The American Physical Society

  5. High Level Analysis, Design and Validation of Distributed Mobile Systems with CoreASM

    Farahbod, R.; Glässer, U.; Jackson, P. J.; Vajihollahi, M.

    System design is a creative activity calling for abstract models that facilitate reasoning about the key system attributes (desired requirements and resulting properties) so as to ensure these attributes are properly established prior to actually building a system. We explore here the practical side of using the abstract state machine (ASM) formalism in combination with the CoreASM open source tool environment for high-level design and experimental validation of complex distributed systems. Emphasizing the early phases of the design process, a guiding principle is to support freedom of experimentation by minimizing the need for encoding. CoreASM has been developed and tested building on a broad scope of applications, spanning computational criminology, maritime surveillance and situation analysis. We critically reexamine here the CoreASM project in light of three different application scenarios.

  6. Antibody to Hepatitis B Core Antigen Levels in the Natural History of Chronic Hepatitis B

    Jia, Wei; Song, Liu-Wei; Fang, Yu-Qing; Xiao-feng WU; Liu, Dan-Yang; Xu, Chun; Wang, Xiao-Mei; Wang, Wen; Lv, Dong-Xia; Li, Jun; Deng, Yong-Qiong; Wang, Yan; Huo, Na; Yu, Min; Xi, Hong-Li

    2014-01-01

    Abstract Previous studies have revealed antibody to hepatitis B core antigen (anti-HBc) levels as a predictor of treatment response in hepatitis B early antigen (HBeAg)-positive chronic hepatitis B (CHB) patients in both interferon and nucleos(t)ide analog therapy cohorts. However, there is no information about anti-HBc levels in the natural history of CHB. This study aimed to define anti-HBc levels of different phases in the natural history of CHB. Two hundred eleven treatment-naive CHB pati...

  7. Multimodel-based power-level control with state-feedback and observer for load-follow PWR core

    Highlights: • The equilibrium manifold and nonlinearity measure of the core are proposed. • The linear multi-model of the core is built based on the core nonlinearity measure. • A new state feedback control is used to design local controllers of the core. • Flexibility partitioning of model and control is presented for the nonlinear core. • The global stability of the core load follow control is analyzed. - Abstract: The purpose of this investigation is that a nonlinear Pressurized Water Reactor (PWR) core load following control system is designed and the global stability of the system is analyzed theoretically. On the basis of modeling a nonlinear PWR core and proposing the equilibrium manifold and the nonlinearity measure of the core to calculate the distribution situation of the core nonlinearity measure in the entire range of power level, linearized models of the core at five power levels are chosen as local models of the core and the set of local models is used to substitute the nonlinear core model. The full-state feedback control with a full-order observer is utilized to design a controller with robustness of every local model, which is treated as a local controller of the nonlinear core. The Kalman filter is contrived as an observer with robustness and the state feedback design with robustness is implemented via the robust pole assignment method. With the local models and local controllers, the flexibility partitioning of model and control is presented to design a decent flexibility controller of the nonlinear core at a random power level. A nonlinear core model and a flexibility controller at a random power level compose a core load following control subsystem. The combination of core load following control subsystems at all power levels is the core load following control system. Two global stability theorems are deduced to define that the core load following control system is globally asymptotically stable within the whole range of power level

  8. Young's double-slit experiment using two-center core-level photoemission: Photoelectron recoil effects

    Core-level photoemission from N2 can be considered an analogue of Young's double-slit experiment (YDSE) in which the double-slit is replaced by a pair of N 1s orbitals. The measured ratio between the 1σg and 1σu photoionization cross-sections oscillates as a function of photoelectron momentum, due to two-center YDSE interference, exhibiting a remarkable dependence on the vibrational sub-levels of the core ionized state. We theoretically demonstrate that the recoil of the photoelectron given to the ionized N atom strongly influences this interference pattern. The reason for this is that the momentum transfer affects the phases of the photoionization amplitudes

  9. Core level spectroscopy in YBa2Cu3O7-δ

    The characterization of the surface electronic structure as a function of the oxygen content by means of photoemission is presented for sintered powders, films and single crystals of YBa2Cu3O7-δ. Core levels lineshapes of O, Ba and Cu are strongly influenced by the oxygen stoichiometry that is varied by heating cycles in vacuo and in O2 atmosphere. The evolution of the core levels following oxygen in- and out-diffusion was followed by X-ray diffraction measurements. The results included in this paper indicate that the observed spectral changes are related to the oxygen deficiency in the chains more than to extrinsic contamination of the surface and point to the importance of charge redistribution and oxygen ordering in the basal plane

  10. Consequence of Job Satisfaction Factors on the Productivity Level of Operating Core

    Baaren, Terence; Galloway, Cornelia

    2014-01-01

    The purpose of this article is to uncover the relationship of job satisfaction factors on the productivity level of operating core of manufacturing firm in textile mill. The theoretical approach that has been in this study to examine job satisfaction is Hertzberg’s two-factor theory of motivation, Maslow’s hierarchy of needs theory. The Minnesota Satisfaction Questionnaire (MSQ) has been used. With the confidence interval of 95% and after analyzing the data and computing the correlation in SP...

  11. A core level spectroscopic study on RNi2B2C (R=Y,Er) borocarbides

    Polycrystalline samples of YNi2B2C and magnetic ErNi2B2C were prepared by arc-melting technique with a Tc ∼ 15 K. Core level spectroscopic studies have been performed in order to see the valence of Y, Er and Ni. The results show that Ni and Er exists in 2+ valence state and Y exists in 3+ valence state. (author)

  12. Quantification of serum hepatitis C virus core protein level in patients chronically infected with different hepatitis C virus genotypes.

    Orito, E; M. Mizokami; Tanaka, T.; Lau, J. Y.; Suzuki, K; Yamauchi, M.; Ohta, Y.; Hasegawa, A; Tanaka, S.; Kohara, M

    1996-01-01

    BACKGROUND/AIM: A novel fluorescent enzyme immunoassay (FEIA) for the detection and quantification of serum hepatitis C virus (HCV) core protein was developed. The aim of this study was to evaluate the relation among serum HCV core protein level, HCV RNA level, and HCV genotype in patients with chronic HCV infection. PATIENTS AND METHODS: Serum HCV core protein, HCV RNA, HCV genotype were determined in 175 patients using the FEIA, branched DNA assay (Quantiplex HCV RNA ver 1.0), and serologic...

  13. Energy and Auger Widths of Triply Excited 3p3p3p 2po State of Lithium

    苟秉聪; 俞开智

    2003-01-01

    The high-lying triply excited 3p3p3p 2po state of the double hollow lithium atom is studied by using the saddlepoint complex-rotation method. The energy and Auger widths of this resonance are calculated. The relativistic corrections and mass polarization are included. The total Auger width is obtained by coupling the important open channels and summing over the other channels. The oscillator strength is also calculated. The results are compared with other theoretical and experimental data in the literature.

  14. A Thin-Core Fiber Modal Interferometer for Liquid-Level Sensing

    A fiber-optic liquid-level sensor is proposed and experimentally demonstrated. It is a Mach—Zehnder interferometer (MZI) composed of a thin-core single-mode fiber (TCSMF) without coating sandwiched between two single-mode fibers (SMFs). The transmission spectrum properties of the MZI modified by liquid around the TCSMF are used for detecting the liquid level. It is found that the sensor exhibits an excellent linear relationship between the level and the shift of interference dip wavelength and its achieved sensitivities are 0.160 nm/mm and 0.288 nm/mm for liquid with an RI of 1.3330 and 1.3696, respectively. Employing the spectrum differential integration (SDI) method to analyze transmission spectra can increase the detecting resolution of the liquid level. Due to its advantages of an extremely easy fabrication process, high sensitivity and a large sensing range, the sensor is an ideal candidate for continuous liquid level sensing

  15. The prediction of two phase mixture level and cooling conditions during a partial core uncovery

    A model for prediction of the reactor core two phase mixture level, as a function of the downcomer level, has been developed. This model assumes quasi-stationary conditions and is applicable at decay heat levels. Another developed model describes the core uncovery process when no make up water is available. In a third model the heat transfer in the uncovered part of the rod bundle is predicted and the rod temperature, as well as the steam superheat temperature, is calculated as a function of time and elevation. This model can be applied for rod temperatures well above 1200 degrees C. These models have been combined and transferred to a computer code and quantities calculated by this such as axial void distribution, two phase level, and rod temperatures have been compared with test data. Comparisons of two phase level and void distributions show good agreement between test data and calculations, within the observed pressure range of 13 to 70 bar. Comparisons of rod temperatures show that they are underpredicted. This is mainly due to the assumption in the model that the channel wall has the same temperature as the fuel rods. This assumption is not valid for the tests compared with in appendix A, in which the channel box is very oversized compared to reactor conditions. In appendix B comparisons with ASEA-ATOM, DRAGON code calculations show that the present model yields a good representation of the core heat up for typical reactor conditions. A comparison with experimental temperature data from the NEPTUN test facility show generally good agreement for all tests compared with in appendix C. (author)

  16. Analysis of core-melt states for the development of detection methods for filling level change and deformation of the core in PWR-type reactors

    The project ''noninvasive status monitoring of nuclear reactors for detection of filling level changes and core deformation'' (NIZUK) is aimed to develop a measuring system for the core status diagnosis during severe accidents in PWR-type reactors. For the development of an appropriate measuring technology the knowledge on the processes during the in-vessel phase of the accident sequence is of main importance. Using the analysis of the accident sequence nine in-vessel phases were defined that are the basis for the development of the measuring system. The differences between the individual core-melt states include the different core geometries and a varying gamma radiation distribution at the reactor pressure vessel outer surface. Especially the appearance of local flow-off paths during a late in-vessel phase requires that several measuring probes with gamma radiation sensors have to be installed around the reactor pressure vessel in order to detect the gamma radiation distribution at the outside. The definition of further core-melt states would be possible in case of a re-flooding of the reactor pressure vessel. However, the increasing filling level would not significantly change the core deformation and the gamma distribution at the outside.

  17. CAIA level I an introduction to core topics in alternative investments

    Anson, Mark J P; CAIA Association; Black, Keith H; Kazemi, Hossein

    2012-01-01

    The official study text for the Level I Chartered Alternative Investment Analyst (CAIA) exam The Chartered Alternative Investment Analyst (CAIA) designation is the financial industry's first and only globally recognized program that prepares professionals to deal with the ever-growing field of alternative investments. The second edition of CAIA Level I: An Introduction to Core Topics in Alternative Investments contains comprehensive insights on the alternative investment issues a potential Level I candidate would need to know about as they prepare for the exam. The information found here will help you build a solid foundation in alternative investment markets--with coverage of everything from the characteristics of various strategies within each alternative asset class to portfolio management concepts central to alternative investments. * Uses investment analytics to examine each alternative asset class * Examines quantitative techniques used by investment professionals * Addresses the unique attributes a...

  18. Characterization of YBa2Cu3Ox using core- and valence-level XPS

    Hundreds of papers have been published involving the photoelectron spectroscopy of the high-Tc superconducting oxides since 1987. The early work, originally on bulk-sintered material, sputtered films, and later on 'single crystals', concentrated on finding 'unusual' features in valence- or core-level spectra to relate to electronic structure effects which might explain the superconducting mechanism. The majority of this work has not adequately taken into account the facts that (a) photoemission probes only the top few monolayers of material, and (b) in many cases the top few layers are completely unrepresentative of the bulk material. This is particularly true for YBa2Cu3Ox, where the surface is extremely reactive, unstable, and prone to contaminating phases, even when prepared under UHV conditions. This has led to a flood of misinformation concerning the true characteristic spectra of this material and their interpretation. In this paper, we present core- and valence-level XPS for YBa2Cu3Ox single-crystal, bulk-sintered, and thin-film samples, and show that, when artifacts are eliminated, the characteristic spectra are the same, to first order, and easily allow distinction of surfaces consisting of the genuine orthorhombic phase (x>6.4) from those with the non-superconducting tetragonal phase (xF, the explanations for the similar 1.5 eV chemical shift in Ba core-level BE between orthorhombic and tetragonal forms, and the implications of the very low O(1s) BE of the orthorhombic form

  19. Characterization of YBa 2Cu 3O x using core- and valence-level XPS

    Brundle, C. R.; Fowler, D. E.

    1993-12-01

    Hundreds of papers have been published involving the photoelectron spectroscopy of the high- Tc superconducting oxides since 1987. The early work, originally on bulk-sintered material, sputtered films, and later on "single crystals", concentrated on finding "unusual" features in valence- or core-level spectra to relate to electronic structure effects which might explain the superconducting mechanism. The majority of this work has not adequately taken into account the facts that (a) photoemission probes only the top few monolayers of material, and (b) in many cases the top few layers are completely unrepresentative of the bulk material. This is particularly true for YBa 2Cu 3O x, where the surface is extremely reactive, unstable, and prone to contaminating phases, even when prepared under UHV conditions. This has led to a flood of misinformation concerning the true characteristic spectra of this material and their interpretation. In this paper, we present core- and valence-level XPS for YBa 2Cu 3O x single-crystal, bulk-sintered, and thin-film samples, and show that, when artifacts are eliminated, the characteristic spectra are the same, to first order, and easily allow distinction of surfaces consisting of the genuine orthorhombic phase ( x > 6.4) from those with the non-superconducting tetragonal phase ( x<6.4) or contaminant or reaction-product phases. With this information, it is possible to eliminate much of the previous literature discussion and also to follow the material changes occuring, for instance, during annealing, adsorption and reaction. We then discuss some detailed interpretations, including the DOS observed at and near EF, the explanations for the ˜1.5 eV chemical shift in Ba core-level BE between orthorhombic and tetragonal forms, and the implications of the very low O(1s) BE of the orthorhombic form.

  20. Production Level CFD Code Acceleration for Hybrid Many-Core Architectures

    Duffy, Austen C.; Hammond, Dana P.; Nielsen, Eric J.

    2012-01-01

    In this work, a novel graphics processing unit (GPU) distributed sharing model for hybrid many-core architectures is introduced and employed in the acceleration of a production-level computational fluid dynamics (CFD) code. The latest generation graphics hardware allows multiple processor cores to simultaneously share a single GPU through concurrent kernel execution. This feature has allowed the NASA FUN3D code to be accelerated in parallel with up to four processor cores sharing a single GPU. For codes to scale and fully use resources on these and the next generation machines, codes will need to employ some type of GPU sharing model, as presented in this work. Findings include the effects of GPU sharing on overall performance. A discussion of the inherent challenges that parallel unstructured CFD codes face in accelerator-based computing environments is included, with considerations for future generation architectures. This work was completed by the author in August 2010, and reflects the analysis and results of the time.

  1. On the core level shifts in semiconductors: A study of the electrostatic model

    A different electrostatic model is proposed for core level shift calculation in semiconductors on the basis of a critical analysis of so-called bond charge model by Bechstedt et al. The population of valence charge on anion and on cation is no longer a linear function of Phillips' ionicity, fsub(i), and a set of additive covalent radii is used instead of a non-additive one. A phenomenological expression is given for bond charge which decreases as ionicity, fsub(i), increases. The results are in agreement with experiments, and the reasons for errors are explained. (author)

  2. Core Journals in library and information science: Measuring the level of specialization over time

    Nicolaisen, Jeppe; Frandsen, Tove Faber

    2013-01-01

    years. The method is applied to a selection of core journals in library and information science (1990-2012). The reference lists of each journal are compared year by year, and the percentage of re-citations is calculated by dividing the number of re-citations with the total number of citations each year...... confirm a positive correlation. Yet, the low r-squared value (R2=0,2811) suggests only a partial explanation of the differences in levels of re-citation. Conclusion. The new method seems to offer a valid technique for measuring scientific specialization as a process. Yet, further studies are required to...

  3. Quanty for core level spectroscopy - excitons, resonances and band excitations in time and frequency domain

    Haverkort, Maurits W.

    2016-05-01

    Depending on the material and edge under consideration, core level spectra manifest themselves as local excitons with multiplets, edge singularities, resonances, or the local projected density of states. Both extremes, i.e., local excitons and non-interacting delocalized excitations are theoretically well under control. Describing the intermediate regime, where local many body interactions and band-formation are equally important is a challenge. Here we discuss how Quanty, a versatile quantum many body script language, can be used to calculate a variety of different core level spectroscopy types on solids and molecules, both in the frequency as well as the time domain. The flexible nature of Quanty allows one to choose different approximations for different edges and materials. For example, using a newly developed method merging ideas from density renormalization group and quantum chemistry [1-3], Quanty can calculate excitons, resonances and band-excitations in x-ray absorption, photoemission, x-ray emission, fluorescence yield, non-resonant inelastic x-ray scattering, resonant inelastic x-ray scattering and many more spectroscopy types. Quanty can be obtained from: http://www.quanty.org.

  4. Core level excitations—A fingerprint of structural and electronic properties of epitaxial silicene

    Friedlein, R., E-mail: friedl@jaist.ac.jp; Fleurence, A.; Aoyagi, K.; Yamada-Takamura, Y. [School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST), 1-1, Asahidai, Nomi, Ishikawa 923-1292 (Japan); Jong, M. P. de; Van Bui, H.; Wiggers, F. B. [MESA Institute for Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands); Yoshimoto, S.; Koitaya, T.; Shimizu, S.; Noritake, H.; Mukai, K.; Yoshinobu, J. [The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

    2014-05-14

    From the analysis of high-resolution Si 2p photoelectron and near-edge x-ray absorption fine structure (NEXAFS) spectra, we show that core level excitations of epitaxial silicene on ZrB{sub 2}(0001) thin films are characteristically different from those of sp{sup 3}-hybridized silicon. In particular, it is revealed that the lower Si 2p binding energies and the low onset in the NEXAFS spectra as well as the occurrence of satellite features in the core level spectra are attributed to the screening by low-energy valence electrons and interband transitions between π bands, respectively. The analysis of observed Si 2p intensities related to chemically distinct Si atoms indicates the presence of at least one previously unidentified component. The presence of this component suggests that the observation of stress-related stripe domains in scanning tunnelling microscopy images is intrinsically linked to the relaxation of Si atoms away from energetically unfavourable positions.

  5. P3P semantic checker of site behaviours

    Grande, Robson Eduardo; Zorzo, Sérgio Donizetti

    2006-01-01

    The interactive use of the web between users and service providers introduces a privacy problem that involves the undesired disclosing of user personal information, mainly with the presence of personalization that needs this type of information. Also there are many manners to face it, but the Platform for Privacy Preferences (P3P) is one that provides a variable level of privacy for the user’s browsing. However, the P3P only introduces a privacy contract between the site and the user, without...

  6. Thermoelastic properties of Zn3P2

    Gerward, Leif; Olsen, J. Staun; Waśkowska, A.

    2011-01-01

    The bulk modulus and thermal expansion of Zn3P2 has been investigated at pressures up to 21GPa and temperatures down to 100K. The experimental zero-pressure bulk modulus is 80.7 ± 1.8GPa, in accordance with the bulk modulus scaling and lattice properties of the related compound Cd3P2. A tetragonal...... to orthorhombic phase transformation occurs above 11GPa with a relative volume change of-7.1%. Values for the thermal expansion coefficient are reported at 293, 200 and 100K....

  7. Significance of common cause failures in level-l PSA and techniques for reducing its impact on core damage frequency

    Failure of multiple components due to a common cause represents one of the most important issues in evaluation of system reliability or unavailability. The frequency of such events has relatively low expectancy, when compared to random failures, which affect individual components. However, in many cases the consequence is a direct loss of safety system or mitigative safety function. For this reason, the modeling of a common cause failure (CCF) and its presentation in fault tree structure is of the uttermost importance in probabilistic safety analyses (PSA). Amongst the different techniques available to reduce the impact of common cause failures, the most important operations related technique, is that of staggered testing. In the TAPP 3,4 Level-1 PSA it was found that the contribution of Common Cause Failures to the Core Damage Frequency (CDF) was significant. The Common Cause Failures were modeled using the Alpha Factor Model. This model is capable of evaluating the impact of staggered testing of components of the redundant standby systems. The NUREG/CR-5801 prescribes a different calculation methodology to evaluate the staggered testing on the Common Cause Failure component group. The proprietary software used for the Level-1 PSA, had a built-in non-staggered testing Alpha factor model. Hence, the factors were modified to introduce the effect of the staggered testing. There was a significant reduction in the CDF due to the introduction of staggered testing. (author)

  8. Optimized surface-slab excited-state muffin-tin potential and surface core level shifts

    An optimized muffin-tin (MT) potential for surface slabs with preassigned surface core-level shifts (SCLS's) is presented. By using the MT radii as adjustable parameters the model is able to conserve the definition of the SCLS with respect to the bulk and concurrently to generate a potential that is continuous at the MT radii. The model is conceived for elastic electron scattering in a surface slab with exchange-correlation interaction described by the local density approximation. The model employs two data bases for the self-energy of the signal electron (after Hedin and Lundqvist or Sernelius). The potential model is discussed in detail with two surface structures Be(101-bar0), for which SCLS's are available, and Cu(111)p(2x2)Cs, in which the close-packed radii of the atoms are extremely different. It is considered plausible that tensor LEED based on an optimized MT potential can be used for determining SCLS's

  9. Core-Level Modeling and Frequency Prediction for DSP Applications on FPGAs

    Gongyu Wang

    2015-01-01

    Full Text Available Field-programmable gate arrays (FPGAs provide a promising technology that can improve performance of many high-performance computing and embedded applications. However, unlike software design tools, the relatively immature state of FPGA tools significantly limits productivity and consequently prevents widespread adoption of the technology. For example, the lengthy design-translate-execute (DTE process often must be iterated to meet the application requirements. Previous works have enabled model-based, design-space exploration to reduce DTE iterations but are limited by a lack of accurate model-based prediction of key design parameters, the most important of which is clock frequency. In this paper, we present a core-level modeling and design (CMD methodology that enables modeling of FPGA applications at an abstract level and yet produces accurate predictions of parameters such as clock frequency, resource utilization (i.e., area, and latency. We evaluate CMD’s prediction methods using several high-performance DSP applications on various families of FPGAs and show an average clock-frequency prediction error of 3.6%, with a worst-case error of 20.4%, compared to the best of existing high-level prediction methods, 13.9% average error with 48.2% worst-case error. We also demonstrate how such prediction enables accurate design-space exploration without coding in a hardware-description language (HDL, significantly reducing the total design time.

  10. An assessment of global and regional sea level for years 1993–2007 in a suite of interannual CORE-II simulations

    Griffies, Stephen M.; Yin, Jianjun; Durack, Paul J.; Goddard, Paul; Bates, Susan C.; Behrens, Erik; Bentsen, Mats; Bi, Daohua; Biastoch, Arne; Böning, Claus W.; Bozec, Alexandra; Chassignet, Eric; Danabasoglu, Gokhan; Danilov, Sergey; Domingues, Catia M.

    2014-01-01

    Highlights: • Global mean sea level simulated in interannual CORE simulations. • Regional sea level patterns simulated in interannual CORE simulations. • Theoretical foundation for analysis of global mean sea level and regional patterns. Abstract: We provide an assessment of sea level simulated in a suite of global ocean-sea ice models using the interannual CORE atmospheric state to determine surface ocean boundary buoyancy and momentum fluxes. These CORE-II simulations are co...

  11. Uncertainties of the neutronic calculations at core level determined by the KARATE code system and the KIKO3D code

    Panka, Istvan; Kereszturi, Andras [Hungarian Academy of Sciences, Budapest (Hungary). Reactor Analysis Dept.

    2013-09-15

    In this paper the uncertainties of the neutronic calculations at core level - originating from the uncertainties of the basic nuclear data - are presented. The investigations have been made for a VVER-1000 core (Kozloduy-6) defined in the frame of the OECD NEA UAM benchmark. In the first part of the paper, the uncertainties of the effective multiplication factor, the assembly-wise radial power distribution, the axial power distribution and the rod worth are shown. After that the preliminary evaluation of the uncertainties of the neutron kinetic calculations are presented for a rod movement transient at HZP (Hot Zero Power) state, where the uncertainties of the time dependent core and assembly powers and the dynamic reactivity were evaluated. In both cases, we will see that the most important quantities - at core level and at HZP state - have a considerable uncertainty which is originating from the uncertainties of the basic cross section library in these investigations. (orig.)

  12. Uncertainties of the neutronic calculations at core level determined by the KARATE code system and the KIKO3D code

    In this paper the uncertainties of the neutronic calculations at core level - originating from the uncertainties of the basic nuclear data - are presented. The investigations have been made for a VVER-1000 core (Kozloduy-6) defined in the frame of the OECD NEA UAM benchmark. In the first part of the paper, the uncertainties of the effective multiplication factor, the assembly-wise radial power distribution, the axial power distribution and the rod worth are shown. After that the preliminary evaluation of the uncertainties of the neutron kinetic calculations are presented for a rod movement transient at HZP (Hot Zero Power) state, where the uncertainties of the time dependent core and assembly powers and the dynamic reactivity were evaluated. In both cases, we will see that the most important quantities - at core level and at HZP state - have a considerable uncertainty which is originating from the uncertainties of the basic cross section library in these investigations. (orig.)

  13. Initial condition for efficient mapping of level set algorithms on many-core architectures

    Tornai, Gábor János; Cserey, György

    2014-12-01

    In this paper, we investigated the effect of adding more small curves to the initial condition which determines the required number of iterations of a fast level set (LS) evolution. As a result, we discovered two new theorems and developed a proof on the worst case of the required number of iterations. Furthermore, we found that these kinds of initial conditions fit well to many-core architectures. To show this, we have included two case studies which are presented on different platforms. One runs on a graphical processing unit (GPU) and the other is executed on a cellular nonlinear network universal machine (CNN-UM). With the new initial conditions, the steady-state solutions of the LS are reached in less than eight iterations depending on the granularity of the initial condition. These dense iterations can be calculated very quickly on many-core platforms according to the two case studies. In the case of the proposed dense initial condition on GPU, there is a significant speedup compared to the sparse initial condition in all cases since our dense initial condition together with the algorithm utilizes the properties of the underlying architecture. Therefore, greater performance gain can be achieved (up to 18 times speedup compared to the sparse initial condition on GPU). Additionally, we have validated our concept against numerically approximated LS evolution of standard flows (mean curvature, Chan-Vese, geodesic active regions). The dice indexes between the fast LS evolutions and the evolutions of the numerically approximated partial differential equations are in the range of 0.99±0.003.

  14. BWR [boiling water reactor] core criticality versus water level during an ATWS [anticipated transient without scram] event

    The BWR [boiling water reactor] emergency procedures guidelines recommend management of core water level to reduce the power generated during an anticipated transient without scram (ATWS) event. BWR power level variation has traditionally been calculated in the system codes using a 1-D [one-dimensional] 2-group neutron kinetics model to determine criticality. This methodology used also for calculating criticality of the partially covered BWR cores has, however, never been validated against data. In this paper, the power level versus water level issues in an ATWS severe accident are introduced and the accuracy of the traditional methodology is investigated by comparing with measured data. It is found that the 1-D 2-group treatment is not adequate for accurate predictions of criticality and therefore the system power level for the water level variations that may be encountered in a prototypical ATWS severe accident. It is believed that the current predictions for power level may be too high

  15. Core-level XPS spectra of fullerene, highly oriented pyrolitic graphite, and glassy carbon

    Leiro, J A; Laiho, T; Batirev, I G

    2003-01-01

    The C 1s spectra of fullerene C sub 6 sub 0 , highly oriented pyrolitic graphite (HOPG) and amorphous carbon (a-C) have been measured using X-ray photoemission. The assumed background due to the inelastic scattering of electrons of these spectra has been subtracted by the Tougaard's method. The relative intensities and the energy positions for the core-level satellites have been determined. For C sub 6 sub 0 , a comparison of the low energy pi type shake-up satellites gives good agreement between theory and experiment. Also, the energies of these features for fullerene and glassy carbon are very similar, whereas the corresponding energies for HOPG are somewhat larger, presumably, because of the higher density of the latter. Moreover, the atomic force microscopy (AFM) study indicates that the C sub 6 sub 0 samples consist of a thick layer of large clusters on the Si(111) surface, which is in line with the molecular character of the XPS spectrum. Furthermore, the broad high energy satellite does not consist of ...

  16. A multi-level parallel computation of reactor cores using GPU for loading pattern optimization

    Efficient and rapid computation of multiple loading patterns using GPU is studied aiming application to loading pattern optimization of LWR. The loading pattern has significant impacts on safety and economy of a reactor. However, design of loading pattern is a combinatorial optimization problem, thus it is computationally intensive task. In order to address this issue, efficient and rapid computation method of loading patterns using massively parallel computing capability of GPU is studied in the present paper. Though GPU has higher computational performance than CPU, but different computational algorithm and coding approach are necessary to maximize the performance of GPU, due to different architecture of GPU. In the present study, a multi-level parallel computing approach is examined considering hardware architecture of GPU, i.e., parallel computing is carried out not only in spatial mesh-wise, but also in loading pattern-wise. In other words, multiple loading patterns are simultaneously computed and domain (mesh-wise) decomposition is applied to each loading pattern. With the present approach, computational efficiency using GPU is approximately four times higher than that of CPU. The present core analysis algorithm can be used for screening of poor loading patterns in optimization process. (author)

  17. Can circular dichroism in core-level photoemission provide a spectral fingerprint of adsorbed chiral molecules?

    Allegretti, F [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Polcik, M [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D 14195 Berlin (Germany); Sayago, D I [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D 14195 Berlin (Germany); Demirors, F [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D 14195 Berlin (Germany); O' Brien, S [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Nisbet, G [Centre for Applied Catalysis, Department of Chemical and Biological Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom); Lamont, C L A [Centre for Applied Catalysis, Department of Chemical and Biological Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH (United Kingdom); Woodruff, D P [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2005-04-01

    The results of experimental measurements and theoretical simulations of circular dichroism in the angular distribution (CDAD) of photoemission from atomic core levels of each of the enantiomers of a chiral molecule, alanine, adsorbed on Cu(1 1 0) are presented. Measurements in, and out of, substrate mirror planes allow one to distinguish the CDAD due to the chirality of the sample from that due to a chiral experimental geometry. For these studies of oriented chiral molecules, the CDAD is seen not only in photoemission from the molecular chiral centre, but also from other atoms which have chiral geometries as a result of the adsorption. The magnitude of the CDAD due to the sample chirality differs for different adsorption phases of alanine, and for different emission angles and energies, but is generally small compared with CDAD out of the substrate mirror planes which is largely unrelated to the molecular chirality. While similar measurements of other molecules may reveal larger CDAD due to molecular chirality, the fact that the results for one chiral molecule show weak effects means that such CDAD is unlikely to provide a simple and routine general spectral fingerprint of adsorbed molecular chirality.

  18. Raising FLAGS: Renewing Core French at the Pre-Service Teacher Level

    Carr, Wendy

    2010-01-01

    A new program for core French teacher candidates called FLAGS (French Language and Global Studies) was established at the University of British Columbia (UBC) in 2007. The program is intended for those who are keen to teach core French and possess rudimentary proficiency in the language but may not necessarily have the same proficiency or prior…

  19. Raising FLAGS: Renewing Core French at the Pre-service Teacher Level

    Wendy Carr

    2010-02-01

    Full Text Available A new program for core French teacher candidates called FLAGS (French Language and Global Studies was established at the University of British Columbia (UBC in 2007. The program is intended for those who are keen to teach core French and possess rudimentary proficiency in the language but may not necessarily have the same proficiency or prior coursework as candidates applying to existing French specialist cohorts. The FLAGS program begins with a five-week summer immersion experience through Explore! and then proceeds with UBC's regular Bachelor of Education program but with an added French conversation course, a core French methodology course and a core French practicum concentration (augmented, in some cases, with a three-week practicum in a francophone locale. FLAGS is intended to address the less than satisfactory state of elementary core French teaching and learning in British Columbia.

  20. Intermediate Coupling For Core-Level Excited States: Consequences For X-Ray Absorption Spectroscopy

    Bagus, Paul S.; Sassi, Michel JPC; Rosso, Kevin M.

    2015-04-15

    The origin of the complex NEXAFS features of X-Ray Absorption, XAS, spectra in transition metal complexes is analyzed and interpreted in terms of the angular momentum coupling of the open shell electrons. Especially for excited configurations where a core-electron is promoted to an open valence shell, the angular momentum coupling is intermediate between the two limits of Russell- Saunders, RS, coupling where spin-orbit splitting of the electron shells is neglected and j-j coupling where this splitting is taken as dominant. The XAS intensities can be understood in terms of two factors: (1) The dipole selection rules that give the allowed excited RS multiplets and (2) The contributions of these allowed multiplets to the wavefunctions of the intermediate coupled levels. It is shown that the origin of the complex XAS spectra is due to the distribution of the RS allowed multiplets over several different intermediate coupled excited levels. The specific case that is analyzed is the L2,3 edge XAS of an Fe3+ cation, because this cation allows a focus on the angular momentum coupling to the exclusion of other effects; e.g., chemical bonding. Arguments are made that the properties identified for this atomic case are relevant for more complex materials. The analysis is based on the properties of fully relativistic, ab initio, many-body wavefunctions for the initial and final states of the XAS process. The wavefunction properties considered include the composition of the wavefunctions in terms of RS multiplets and the occupations of the spin-orbit split open shells; the latter vividly show whether the coupling is j-j or not.

  1. Engineering task plan for upgrades to the leveling jacks on core sample trucks number 3 and 4; TOPICAL

    Characterizing the waste in underground storage tanks at the Hanford Site is accomplished by obtaining a representative core sample for analysis. Core sampling is one of the numerous techniques that have been developed for use given the environmental and field conditions at the Hanford Site. Core sampling is currently accomplished using either Push Mode Core Sample Truck No.1 or; Rotary Mode Core Sample Trucks No.2, 3 or 4. Past analysis (WHC 1994) has indicated that the Core Sample Truck (CST) leveling jacks are structurally inadequate when lateral loads are applied. WHC 1994 identifies many areas where failure could occur. All these failures are based on exceeding the allowable stresses listed in the American Institute of Steel Construction (AISC) code. The mode of failure is for the outrigger attachments to the truck frame to fail resulting in dropping of the CST and possible overturning (Ref. Ziada and Hundal, 1996). Out of level deployment of the truck can exceed the code allowable stresses in the structure. Calculations have been performed to establish limits for maintaining the truck level when lifting. The calculations and the associated limits are included in appendix A. The need for future operations of the CSTS is limited. Sampling is expected to be complete in FY-2001. Since there is limited time at risk for continued use of the CSTS with the leveling controls without correcting the structural problems, there are several design changes that could give incremental improvements to the operational safety of the CSTS with limited impact on available operating time. The improvements focus on making the truck easier to control during lifting and leveling. Not all of the tasks identified in this ETP need to be performed. Each task alone can improve the safety. This engineering task plan is the management plan document for implementing the necessary additional structural analysis. Any additional changes to meet requirements of standing orders shall require a

  2. Doubly excited 3P(e) resonant states in Ps(-)

    Ho, Y. K.; Bhatia, A. K.

    1992-01-01

    Doubly excited 3P(e) resonant states in Ps(-) are calculated using a method of complex-coordinate rotation. Resonance parameters (both resonance positions and widths) for doubly excited states associated with the n = 2, 3, 4, 5, and 6 thresholds of positronium atoms are evaluated using elaborate Hylleraas-type functions. In addition to ten Feshbach-type resonances lying below various Ps thresholds, three shape resonances were identified, one each lying above the n = 2, 4, and 6 Ps thresholds. It is further noted that the energy levels for the present 3P(e) states are nearly degenerate with respect to the previously calculated 1P(0) states. Such a symmetric character suggests that the highly and doubly excited Ps(-), similar to its counterpart in H(-), would exhibit rovibrational behaviors analogous to those of XYX triatomic molecules.

  3. Effects on intercombination transition rates and branching ratios-the UV0.01 (3s{sup 2}3p{sup 2} {sup 3}P{sub 1,2} - 3s3p{sup 3} {sup 5}S{sub 2}) multiplet in Si I-like ions revisited

    Andersson, Martin; Brage, Tomas [Department of Physics, Lund University, Box 118, SE-221 00 Lund (Sweden)

    2007-02-28

    We report on large-scale ab initio calculations for intercombination lines in Si I-like ions. Two measurable quantities, the lifetime of the 3s3p{sup 3} {sup 5}S{sub 2} level and the branching ratio of the two lines are discussed, to infer the importance of different features of our calculations. The effects of core polarization, two-body spin-dependent operators and Dirac contra Breit-Pauli approaches are discussed. Earlier calculations are reviewed and evaluated. The calculated lifetimes are in good agreement with experiments, while a discrepancy persists for branching ratios.

  4. Test Plan for Rotary Mode Core Sample Truck Grapple Hoist Level Wind System

    A Grapple Hoist Assembly is currently used on the Rotary Mode Core Sampling Trucks (RMCSTs) to actuate the sampler and retrieve the pintle rod during sampling operations. The hoist assembly includes a driven drum approximately two inches wide and six inches in diameter that rotates to pay out or reel in the 5/32-in. cable The current Grapple Hoist Assembly, detailed on drawing H-2-690057, is prone to ''bird nesting'' the cable on the drum. ''Bird nesting'' is a condition in which the cable does not wind onto the drum in a uniformly layered manner, but winds in a random fashion where the cable essentially ''piles up'' inappropriately on the drum and, on some occasions, winds on the drum drive shaft. A system to help control this ''bird nesting'' problem has been designed as an addition to the existing components of the Grapple Hoist Assembly. The new design consists of a mechanism that is timed with, and driven by, the shaft that drives the drum. This mechanism traverses back and forth across the width of the drum to lay the cable on the drum in a uniformly layered manner. This test plan establishes the acceptance criteria, test procedure and test conditions It also describes the test apparatus necessary to verify the adequacy of the level wind system design. The test is defined as qualification testing (LMHC 1999b) and as such will be performed at conditions beyond the parameters that the Grapple Hoist Assembly is allowed to operate by the Safety Equipment List (SEL)(LMHC 1998)

  5. Test Plan for Rotary Mode Core Sample Truck Grapple Hoist Level Wind System

    A Grapple Hoist Assembly is currently used on the Rotary Mode Core Sampling Trucks (RMCSTs) to actuate the sampler and retrieve the pintle rod during sampling operations. The hoist assembly includes a driven drum approximately two inches wide and six inches in diameter that rotates to pay out or reel in the 5/32-in. cable. The current Grapple Hoist Assembly, detailed on drawing H-2-690057, is prone to ''bird nesting'' the cable on the drum. ''Bird nesting'' is a condition in which the cable does not wind onto the drum in a uniformly layered manner, but winds in a random fashion where the cable essentially ''piles up'' inappropriately on the drum and, on some occasions, winds on the drum drive shaft. A system to help control this ''bird nesting'' problem has been designed as an addition to the existing components of the Grapple Hoist Assembly. The new design consists of a mechanism that is timed with, and driven by, the shaft that drives the drum. This mechanism traverses back and forth across the width of the drum to lay the cable on the drum in a uniformly layered manner. This test plan establishes the acceptance criteria, test procedure and test conditions. It also describes the test apparatus necessary to verify the adequacy of the level wind system design. The test is defined as qualification testing (LMHC 1999b) and as such will be performed at conditions beyond the parameters that the Grapple Hoist Assembly is allowed to operate by the Safety Equipment List

  6. An implementation of core level spectroscopies in a real space Projector Augmented Wave density functional theory code

    Ljungberg, M.P.; Mortensen, Jens Jørgen; Pettersson, L.G.M.

    2011-01-01

    We describe the implementation of K-shell core level spectroscopies (X-ray absorption (XAS), X-ray emission (XES), and X-ray photoemission (XPS)) in the real-space-grid-based Projector Augmented Wave (PAW) GPAW code. The implementation for XAS is based on the Haydock recursion method avoiding...

  7. Real-time TDDFT simulations of time-resolved core-level spectroscopies in solid state systems

    Pemmaraju, Sri Chaitanya Das; Prendergast, David; Theory of Nanostructured Materials Facility Team

    The advent of sub-femtosecond time-resolved core-level spectroscopies based on high harmonic generated XUV pulses has enabled the study of electron dyanamics on characteristic femtosecond time-scales. Unambiguous interpretation of these powerful yet complex spectroscopies however requires the development of theoretical algorithms capable of modeling light-matter interaction across a wide energy range spanning both valence and core orbitals. In this context we present a recent implementation of the velocity-gauge formalism of real-time TDDFT within a linear combination of atomic orbital (LCAO) framework, which facilitates efficient numerical treatment of localized semi-core orbitals. Dynamics and spectra obtained from LCAO based simulations are compared to those from a real-space grid implementation. Potential applications are also illustrated by applying the method towards interpreting recent atto-second time-resolved IR-pump XUV-probe spectroscopies investigating sub-cycle excitation dynamics in bulk silicon.

  8. Adlayer Core-Level Shifts of Random Metal Overlayers on Transition-Metal Substrates

    Ganduglia-Pirovano, M. V.; Kudrnovský, J.; Scheffler, M.

    1997-01-01

    We calculate the difference of the ionization energies of a core electron of a surface alloy, i.e., a B atom in a A(1-x)B(x) overlayer on a fee B(001) substrate, and a core electron of the clean fee B(001) surface using density-functional theory. We analyze the initial-state contributions and the...... the initial-state trends are explained in terms of the change of inter- and intra-atomic screening upon alloying. A possible role of alloying on the chemical reactivity of metal surfaces is discussed....

  9. First principle calculations of core-level binding energy and Auger kinetic energy shifts in metallic solids

    Olovsson, Weine, E-mail: weine.olovsson@gmail.co [Department of Materials Science and Engineering, Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Marten, Tobias [Department of Physics, Chemistry and Biology (IFM), Linkoeping University, SE-581 83 Linkoeping (Sweden); Holmstroem, Erik [Instituto de Fisica, Universidad Austral de Chile, Valdivia (Chile); Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Johansson, Boerje [Department of Physics and Materials Science, Uppsala University, P.O. Box 530, SE-751 21 Uppsala (Sweden); Applied Materials Physics, Department of Materials and Engineering, Royal Institute of Technology (KTH), SE-100 44 Stockholm (Sweden); Abrikosov, Igor A. [Department of Physics, Chemistry and Biology (IFM), Linkoeping University, SE-581 83 Linkoeping (Sweden)

    2010-05-15

    We present a brief overview of recent theoretical studies of the core-level binding energy shift (CLS) in solid metallic materials. The focus is on first principles calculations using the complete screening picture, which incorporates the initial (ground state) and final (core-ionized) state contributions of the electron photoemission process in X-ray photoelectron spectroscopy (XPS), all within density functional theory (DFT). Considering substitutionally disordered binary alloys, we demonstrate that on the one hand CLS depend on average conditions, such as volume and overall composition, while on the other hand they are sensitive to the specific local atomic environment. The possibility of employing layer resolved shifts as a tool for characterizing interface quality in fully embedded thin films is also discussed, with examples for CuNi systems. An extension of the complete screening picture to core-core-core Auger transitions is given, and new results for the influence of local environment effects on Auger kinetic energy shifts in fcc AgPd are presented.

  10. Cancer core modules identification through genomic and transcriptomic changes correlation detection at network level

    Li Wenting

    2012-06-01

    Full Text Available Abstract Background Identification of driver mutations among numerous genomic alternations remains a critical challenge to the elucidation of the underlying mechanisms of cancer. Because driver mutations by definition are associated with a greater number of cancer phenotypes compared to other mutations, we hypothesized that driver mutations could more easily be identified once the genotype-phenotype correlations are detected across tumor samples. Results In this study, we describe a novel network analysis to identify the driver mutation through integrating both cancer genomes and transcriptomes. Our method successfully identified a significant genotype-phenotype change correlation in all six solid tumor types and revealed core modules that contain both significantly enriched somatic mutations and aberrant expression changes specific to tumor development. Moreover, we found that the majority of these core modules contained well known cancer driver mutations, and that their mutated genes tended to occur at hub genes with central regulatory roles. In these mutated genes, the majority were cancer-type specific and exhibited a closer relationship within the same cancer type rather than across cancer types. The remaining mutated genes that exist in multiple cancer types led to two cancer type clusters, one cluster consisted of three neural derived or related cancer types, and the other cluster consisted of two adenoma cancer types. Conclusions Our approach can successfully identify the candidate drivers from the core modules. Comprehensive network analysis on the core modules potentially provides critical insights into convergent cancer development in different organs.

  11. Microstructure-dependent mechanical properties of electrospun core-shell scaffolds at multi-scale levels.

    Horner, Christopher B; Ico, Gerardo; Johnson, Jed; Zhao, Yi; Nam, Jin

    2016-06-01

    Mechanical factors among many physiochemical properties of scaffolds for stem cell-based tissue engineering significantly affect tissue morphogenesis by controlling stem cell behaviors including proliferation and phenotype-specific differentiation. Core-shell electrospinning provides a unique opportunity to control mechanical properties of scaffolds independent of surface chemistry, rendering a greater freedom to tailor design for specific applications. In this study, we synthesized electrospun core-shell scaffolds having different core composition and/or core-to-shell dimensional ratios. Two independent biocompatible polymer systems, polyetherketoneketone (PEKK) and gelatin as the core materials while maintaining the shell polymer with polycaprolactone (PCL), were utilized. The mechanics of such scaffolds was analyzed at the microscale and macroscales to determine the potential implications it may hold for cell-material and tissue-material interactions. The mechanical properties of individual core-shell fibers were controlled by core-shell composition and structure. The individual fiber modulus correlated with the increase in percent core size ranging from 0.55±0.10GPa to 1.74±0.22GPa and 0.48±0.12GPa to 1.53±0.12GPa for the PEKK-PCL and gelatin-PCL fibers, respectively. More importantly, it was demonstrated that mechanical properties of the scaffolds at the macroscale were dominantly determined by porosity under compression. The increase of scaffold porosity from 70.2%±1.0% to 93.2%±0.5% by increasing the core size in the PEKK-PCL scaffold resulted in the decrease of the compressive elastic modulus from 227.67±20.39kPa to 14.55±1.43kPa while a greater changes in the porosity of gelatin-PCL scaffold from 54.5%±4.2% to 89.6%±0.4% resulted in the compressive elastic modulus change from 484.01±30.18kPa to 17.57±1.40kPa. On the other hand, the biphasic behaviors under tensile mechanical loading result in a range from a minimum of 5.42±1.05MPa to a maximum

  12. Species-level core oral bacteriome identified by 16S rRNA pyrosequencing in a healthy young Arab population

    Nezar Noor Al-hebshi

    2016-05-01

    Full Text Available Background: Reports on the composition of oral bacteriome in Arabs are lacking. In addition, the majority of previous studies on other ethnic groups have been limited by low-resolution taxonomic assignment of next-generation sequencing reads. Furthermore, there has been a conflict about the existence of a ‘core’ bacteriome. Objective: The objective of this study was to characterize the healthy core oral bacteriome in a young Arab population at the species level. Methods: Oral rinse DNA samples obtained from 12 stringently selected healthy young subjects of Arab origin were pyrosequenced (454's FLX chemistry for the bacterial 16S V1–V3 hypervariable region at an average depth of 11,500 reads. High-quality, non-chimeric reads ≥380 bp were classified to the species level using the recently described, prioritized, multistage assignment algorithm. A core bacteriome was defined as taxa present in at least 11 samples. The Chao2, abundance-based coverage estimator (ACE, and Shannon indices were computed to assess species richness and diversity. Results: Overall, 557 species-level taxa (211±42 per subject were identified, representing 122 genera and 13 phyla. The core bacteriome comprised 55 species-level taxa belonging to 30 genera and 7 phyla, namely Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, Fusobacteria, Saccharibacteria, and SR1. The core species constituted between 67 and 87% of the individual bacteriomes. However, the abundances differed by up to three orders of magnitude among the study subjects. On average, Streptococcus mitis, Rothia mucilaginosa, Haemophilus parainfluenzae, Neisseria flavescence/subflava group, Prevotella melaninogenica, and Veillonella parvula group were the most abundant. Streptococcus sp. C300, a taxon never reported in the oral cavity, was identified as a core species. Species richness was estimated at 586 (Chao2 and 614 (ACE species, whereas diversity (Shannon index averaged at 3.99. Conclusions

  13. Theoretical predictions of the impact of nuclear dynamics and environment on core-level spectra of organic molecules

    Prendergast, David; Schwartz, Craig; Uejio, Janel; Saykally, Richard

    2009-03-01

    Core-level spectroscopy provides an element-specific probe of local electronic structure and bonding, but linking details of atomic structure to measured spectra relies heavily on accurate theoretical interpretation. We present first principles simulations of the x-ray absorption of a range of organic molecules both in isolation and aqueous solvation, highlighting the spectral impact of internal nuclear motion as well as solvent interactions. Our approach uses density functional theory with explicit inclusion of the core-level excited state within a plane-wave supercell framework. Nuclear degrees of freedom are sampled using various molecular dynamics techniques. We indicate specific cases for molecules in their vibrational ground state at experimental conditions, where nuclear quantum effects must be included. Prepared by LBNL under Contract DE-AC02-05CH11231.

  14. Effects of non-local exchange on core level shifts for gas-phase and adsorbed molecules

    Density functional theory calculations are often used to interpret experimental shifts in core level binding energies. Calculations based on gradient-corrected (GC) exchange-correlation functionals are known to reproduce measured core level shifts (CLS) of isolated molecules and metal surfaces with reasonable accuracy. In the present study, we discuss a series of examples where the shifts calculated within a GC-functional significantly deviate from the experimental values, namely the CLS of C 1s in ethyl trifluoroacetate, Pd 3d in PdO and the O 1s shift for CO adsorbed on PdO(101). The deviations are traced to effects of the electronic self-interaction error with GC-functionals and substantially better agreements between calculated and measured CLS are obtained when a fraction of exact exchange is used in the exchange-correlation functional

  15. Recommendations for Training in Pediatric Psychology: Defining Core Competencies Across Training Levels

    Palermo, Tonya M.; Janicke, David M; McQuaid, Elizabeth L.; Mullins, Larry L.; Robins, Paul M.; Wu, Yelena P.

    2014-01-01

    Objective As a field, pediatric psychology has focused considerable efforts on the education and training of students and practitioners. Alongside a broader movement toward competency attainment in professional psychology and within the health professions, the Society of Pediatric Psychology commissioned a Task Force to establish core competencies in pediatric psychology and address the need for contemporary training recommendations. Methods The Task Force adapted the framework proposed by th...

  16. Irradiation-induced softening of Ni3P and (Ni, Fe, Cr)3P alloys

    Production of amorphous alloys by solid state reactions (SSR) has attracted much interest during the last few years. One of the methods to induce such a reaction is the irradiation of suitable crystalline alloys by fast particles. Examination of this kind of SSR in M3P type of brazing alloys (M: Metal) is attractive because of the following reason: In brazed joints of candidate structural materials like 316L stainless steel for applications in fusion reactors, crystalline intermetallic phases have been detected which are unstable relative to the amorphous state when irradiated at moderate temperatures with fast particles. It is expected that the transition to the amorphous state is accompanied by changes of the mechanical properties, which are of fundamental interest in this context. Until now, only a few studies on the evolution of mechanical properties during amorphization have been performed. Measurements of microhardness of the crystalline and the corresponding amorphous phase do not exist to the authors knowledge. In this communication, the authors present results on changes of microhardness, due to amorphization by fast ions. The measurements have been performed on a model alloy Ni3P and on the brazed joint of stainless steel 316L, containing M3P (M: Ni, Fe, Cr) as one of the phases. Though microhardness is not a fundamental property of materials, it is a manifestation of several related properties, such as yield stress, ductility, work-hardening, elastic modulus and residual stress states. It represents a resistance for indentation and is, therefore, appropriate for comparative purposes

  17. A survey of core and support activities of communicable disease surveillance systems at operating-level CDCs in China

    Li Liming

    2010-11-01

    Full Text Available Abstract Background In recent years, problems like insufficient coordination, low efficiency, and heavy working load in national communicable disease surveillance systems in China have been pointed out by many researchers. To strengthen the national communicable disease surveillance systems becomes an immediate concern. Since the World Health Organization has recommended that a structured approach to strengthen national communicable disease surveillance must include an evaluation to existing systems which usually begins with a systematic description, we conducted the first survey for communicable disease surveillance systems in China, in order to understand the situation of core and support surveillance activities at province-level and county-level centers for disease control and prevention (CDCs. Methods A nationwide survey was conducted by mail between May and October 2006 to investigate the implementation of core and support activities of the Notifiable Disease Reporting System (NDRS and disease-specific surveillance systems in all of the 31 province-level and selected 14 county-level CDCs in Mainland China The comments on the performance of communicable disease surveillance systems were also collected from the directors of CDCs in this survey. Results The core activities of NDRS such as confirmation, reporting and analysis and some support activities such as supervision and staff training were found sufficient in both province-level and county-level surveyed CDCs, but other support activities including information feedback, equipment and financial support need to be strengthened in most of the investigated CDCs. A total of 47 communicable diseases or syndromes were under surveillance at province level, and 20 diseases or syndromes at county level. The activities among different disease-specific surveillance systems varied widely. Acute flaccid paralysis (AFP, measles and tuberculosis (TB surveillance systems got relatively high recognition

  18. Core energy levels of Sc and N and their variation with coordination number in ScN

    Šimůnek, Antonín; Vackář, Jiří; Kunc, K.

    2005-01-01

    Roč. 72, č. 4 (2005), 045110/1-045110/4. ISSN 1098-0121 R&D Projects: GA AV ČR(CZ) IAA100100514; GA AV ČR(CZ) IAA1010317 Grant ostatní: NATO(XE) PST -CLG.979025 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z10100521 Keywords : core levels * total energy * ScN Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.185, year: 2005

  19. Simultaneous measurement of neutron and gamma-ray radiation levels from a TRIGA reactor core using silicon carbide semiconductor detectors

    Dulloo, A.R.; Ruddy, F.H.; Seidel, J.G. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States); Davison, C.; Flinchbaugh, T.; Daubenspeck, T. [Pennsylvania State Univ., University Park, PA (United States). Radiation Science and Engineering Center

    1999-06-01

    The ability of a silicon carbide radiation detector to measure neutron and gamma radiation levels in a TRIGA reactor`s mixed neutron/gamma field was demonstrated. Linear responses to epicadmium neutron fluence rate (up to 3 {times} 10{sup 7} cm{sup {minus}2} s{sup {minus}1}) and to gamma dose rate (0.6--234 krad-Si h{sup {minus}1}) were obtained with the detector. Axial profiles of the reactor core`s neutron and gamma-ray radiation levels were successfully generated through sequential measurements along the length of the core. The SiC detector shows a high level of precision for both neutrons and gamma rays in high-intensity radiation environments--1.9% for neutrons and better than 0.6% for gamma rays. These results indicate that SiC detectors are well suited for applications such as spent fuel monitoring where measurements in mixed neutron/gamma fields are desired.

  20. Coordination-resolved local bond strain and 3p energy entrapment of K atomic clusters and K(1 1 0) skin

    Graphical abstract: - Highlights: • Coordination environment resolves electron binding-energy shift of K44, K46, K55 clusters. • Predict the effective coordination number of K nanoclusters when we get the atomic number N. • Atomic under coordination shortens the local bonds and entrapment. • XPS derives core level of an isolated atom and its bulk shift. - Abstract: We have examined the atomic coordination effect on the local bond strain and the 3p core-level shift of K(1 1 0) skin and nanoclusters using a combination of the bond order–length–strength correlation notion, tight-binding approach, density functional theory calculations, and photoelectron spectroscopy measurements. It turns out that: (i) the 3p core-level shifts from 15.595 ± 0.003 eV for an isolated K atom by 2.758 eV to the bulk value of 18.353 eV; (ii) the effective atomic coordination number reduces from the bulk value of 12 to 3.93 for the first layer and to 5.81 for the second layer of K(1 1 0) skin associated with the local lattice strain of 12.76%, a binding energy density 72.67%, and atomic cohesive energy −62.46% for the skin; and (iii) K cluster size reduction lowers the effective atomic coordination number and enhances further the skin electronic attribution. Results have revealed that the 3p core-level shifts of K(1 1 0) and nanoclusters originate from perturbation of the Hamiltonian by under-coordination induced charge densification and quantum entrapment

  1. Coordination-resolved local bond strain and 3p energy entrapment of K atomic clusters and K(1 1 0) skin

    Zhang, Ting; Bo, Maolin; Guo, Yongling [Key Laboratory of Low-Dimensional Materials and Application Technologies (Ministry of Education), Faculty of Materials Science and Engineering, Xiangtan University, Hunan 411105 (China); Hunan Provincial Key Laboratory of Thin Film Materials and Devices, Faculty of Materials Science and Engineering, Xiangtan University, Hunan 411105 (China); Chen, Hefeng [United Superconductive Institution, Shanghai Jiaotong University, Shanghai 200240 (China); Wang, Yan [School of Information and Electronic Engineering, Hunan University of Science and Technology, Hunan 411201 (China); Huang, Yongli, E-mail: huangyongli@xtu.edu.cn [Key Laboratory of Low-Dimensional Materials and Application Technologies (Ministry of Education), Faculty of Materials Science and Engineering, Xiangtan University, Hunan 411105 (China); Hunan Provincial Key Laboratory of Thin Film Materials and Devices, Faculty of Materials Science and Engineering, Xiangtan University, Hunan 411105 (China); Sun, Chang Q., E-mail: ecqsun@ntu.edu.sg [Key Laboratory of Low-Dimensional Materials and Application Technologies (Ministry of Education), Faculty of Materials Science and Engineering, Xiangtan University, Hunan 411105 (China); Hunan Provincial Key Laboratory of Thin Film Materials and Devices, Faculty of Materials Science and Engineering, Xiangtan University, Hunan 411105 (China); School of Information and Electronic Engineering, Hunan University of Science and Technology, Hunan 411201 (China); NOVITAS, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2015-09-15

    Graphical abstract: - Highlights: • Coordination environment resolves electron binding-energy shift of K{sub 44}, K{sub 46}, K{sub 55} clusters. • Predict the effective coordination number of K nanoclusters when we get the atomic number N. • Atomic under coordination shortens the local bonds and entrapment. • XPS derives core level of an isolated atom and its bulk shift. - Abstract: We have examined the atomic coordination effect on the local bond strain and the 3p core-level shift of K(1 1 0) skin and nanoclusters using a combination of the bond order–length–strength correlation notion, tight-binding approach, density functional theory calculations, and photoelectron spectroscopy measurements. It turns out that: (i) the 3p core-level shifts from 15.595 ± 0.003 eV for an isolated K atom by 2.758 eV to the bulk value of 18.353 eV; (ii) the effective atomic coordination number reduces from the bulk value of 12 to 3.93 for the first layer and to 5.81 for the second layer of K(1 1 0) skin associated with the local lattice strain of 12.76%, a binding energy density 72.67%, and atomic cohesive energy −62.46% for the skin; and (iii) K cluster size reduction lowers the effective atomic coordination number and enhances further the skin electronic attribution. Results have revealed that the 3p core-level shifts of K(1 1 0) and nanoclusters originate from perturbation of the Hamiltonian by under-coordination induced charge densification and quantum entrapment.

  2. Numerical analysis of the reactivity for the dry lattices above the water level of the critical fuel cores

    Criticality analysis has been performed for dozens of tank type cores in which fuel lattices are loaded vertically and partially immersed in light water. The reactivity effect of dry part of lattices stuck above the critical water level has been calculated using the continuous energy Monte Carlo method. The reactivity effect exceeds 0.8% both for MOX and UOX fuel lattices of large buckling (Bz2 > 0.0025 cm-2). It is evaluated that at least 20 cm length of fuel rods above the critical water level has significant reactivity effect. (author)

  3. Magnetism and electronic properties of Mn:Ge(111) interfaces probed by core level photoemission spectroscopy

    The electronic and magnetic properties of Mn:Ge(111) interfaces have been investigated by photoelectron spectroscopy and SQUID magnetometry. An ordered, metallic and ferromagnetic, Mn:Ge(111) interface and a disordered, semiconducting and paramagnetic, MnxGe1-x surface alloy have been considered. An analysis of the Mn 2p X-ray photoemission core line shows that the former interface can be described by a single-configuration Mn 3d6 initial state, while the latter presents satellite features typical of Mn-based diluted magnetic semiconductors, characterized by relevant ligand-to-metal charge transfer effects.

  4. Spectra and oscillator strengths of 3p63d9-3p53d10 and 3p63d9-3p63d84p transitions for cobalt-like Sn23+ ion

    Chen Ming-Lun; Yu Xiao-Guang

    2009-01-01

    This paper calculates the spectra and oscillator strengths for highly ionized cobalt-like Sn23+ ions 3p63d9-3p53d10,3p63d9 - 3p63d84p transitions by using a multi-configuration self-consistent field method program together with the proposed fitting formula. The calculations have a good agreement with observations.

  5. Determination of the level of water in the core of reactors PWR using neutron detectors signal ex core; Determinacion del nivel del agua del nucleo de reactores PWR usando la senal de detectores neutronicos excore

    Bernal, A.; Abarca, A.; Miro, R.; Verdu, G.

    2014-07-01

    The level of water from the core provides relevant information of the neutronic and thermal hydraulic of the reactor as the power, k EFF and cooling capacity. In fact, this level monitoring can be used for prediction of LOCA and reduction of cooling that can cause damage to the core. There are several teams that measure a variety of parameters of the reactor, as opposed to the level of the water of the core. However, the detectors 'excore' measure fast neutrons which escape from the core and there are studies that demonstrate the existence of a relationship between them and the water level of the kernel due to the water shield. Therefore, a methodology has been developed to determine this relationship, using the Monte Carlo method using the MCNP code and apply variance reduction techniques based on the attached flow that is obtained using the method of discrete ordinates using code TORT. (Author)

  6. Differential cross section of metastable Ne(3P0 and 3P2) scattered from ground state neon

    The differential elastic cross section for metastable Ne(3P0 and 3P2) from ground state Ne at collision energies between 70 and 150 meV have been measured. With a CW-dye laser it was possible to separate the cross sections for Ne(3P0) + Ne and Ne(3P2) + Ne and for the energy exchange process 20Ne* + 22Ne → 20Ne + 22Ne*. (Auth.)

  7. Association of Mutations in the Basal Core Promoter and Pre-core Regions of the Hepatitis B Viral Genome and Longitudinal Changes in HBV Level in HBeAg Negative Individuals: Results From a Cohort Study in Northern Iran

    Besharat, Sima; Poustchi, Hossein; Mohamadkhani, Ashraf; Katoonizadeh, Aezam; Moradi, Abdolvahab; Roshandel, Gholamreza; Freedman, Neal David; Malekzadeh, Reza

    2015-01-01

    Background: Although certain HBV mutations are known to affect the expression of Hepatitis e antigen, their association with HBV viral level or clinical outcomes is less clear. Objectives: We evaluated associations between different mutations in the Basal Core promoter (BCP) and Pre-core (PC) regions of HBV genome and subsequent changes in HBV viral DNA level over seven years in a population of untreated HBeAg negative chronic hepatitis B (CHB) participants in Northeast of Iran. Materials and...

  8. Differential cross section for Ne(3P0) and Ne(3P2) scattered from ground state neon

    The differential elastic cross sections for electronically excited Ne(3P0) and Ne(3P2) from ground state neon atoms at thermal collision energies have been measured separately. Potentials for Ne(3P0)+Ne could be determined and the height of the intermediate potential maxima for Ne(3P2)+Ne could be estimated to 25 meV. By preparing Ne(3P2) in special Msub(J) states scattering in single Ω molecular states could be observed. (Auth.)

  9. Differential cross section for Ne(3P0) and Ne(3P2) scattered from ground state neon

    The differential elastic cross sections for electronically exited Ne(3P0) and Ne(3P2) from ground state neon atoms at thermal collision energies have been measured separately. Potentials for Ne(3P0)+Ne could be determined and the height of the intermediate potential maxima for Ne(3P2)+Ne could be estimated to 25 meV. By preparing Ne(3P2) in special Msub(J) states scattering in single Ω molecular states could be observed. (Author)

  10. Graphene on Au-coated SiOx substrate: Its visibility and intrinsic core-level photoemission

    Wu, Chung-Lin; Chen, Jhih-Wei; Wang, Chiang-Lun; Chen, Chia-Hao; Chen, Yi-Chun

    2012-02-01

    With the motivation of precisely and intrinsically characterizing a exfoliate graphene using photoelectron spectroscopy, a conducting substrate having high optical contrast is greatly desired. Here, we demonstrate that exfoliated graphene can be optically visible on a thin 9-nm Au-coated SiOx substrate, and can be easily conducted into scanning photoelectron microscopy/spectroscopy (SPEM/S) studies. Because of the elimination of charging effect, precisely core-level characterization of exfoliated graphene is presented with different numbers of layers. Consequently, the usage of Au-coated SiOx substrate serves a simple but effective method to study pristine graphene by photoelectron spectroscopy and other electron-detection techniques.

  11. PAW [Physics Analysis Workstation] at Fermilab: CORE based graphics implementation of HIGZ [High Level Interface to Graphics and Zebra

    The Physics Analysis Workstation system (PAW) is primarily intended to be the last link in the analysis chain of experimental data. The graphical part of PAW is based on HIGZ (High Level Interface to Graphics and Zebra), which is based on the OSI and ANSI standard Graphics Kernel System (GKS). HIGZ is written in the context of PAW. At Fermilab, the CORE based graphics system DI-3000 by Precision Visuals Inc., is widely used in the analysis of experimental data. The graphical part of the PAW routines has been totally rewritten and implemented in the Fermilab environment. 3 refs

  12. Photoelectron spectroscopy at a free-electron laser. Investigation of space-charge effects in angle-resolved and core-level spectroscopy and realizaton of a time-resolved core-level photoemission experiment

    The free-electron laser (FEL) in Hamburg (FLASH) is a very interesting light source with which to perform photoelectron spectroscopy (PES) experiments. Its special characteristics include highly intense photon pulses (up to 100 J/pulse), a photon energy range of 30 eV to 1500 eV, transverse coherence as well as pulse durations of some ten femtoseconds. Especially in terms of time-resolved PES (TRPES), the deeper lying core levels can be reached with photon energies up to 1500 eV with acceptable intensity now and, therefore, element-specific, time-resolved core-level PES (XPS) is feasible at FLASH. During the work of this thesis various experimental setups were constructed in order to realize angle-resolved (ARPES), core-level (XPS) as well as time-resolved PES experiments at the plane grating monochromator beamline PG2 at FLASH. Existing as well as newly developed systems for online monitoring of FEL pulse intensities and generating spatial and temporal overlap of FEL and optical laser pulses for time-resolved experiments are successfully integrated into the experimental setup for PES. In order to understand space-charge effects (SCEs) in PES and, therefore, being able to handle those effects in future experiments using highly intense and pulsed photon sources, the origin of energetic broadenings and shifts in photoelectron spectra are studied by means of a molecular dynamic N-body simulation using a modified Treecode Algorithm for sufficiently fast and accurate calculations. It turned out that the most influencing parameter is the ''linear electron density'' - the ratio of the number of photoelectrons to the diameter of the illuminated spot on the sample. Furthermore, the simulations could reproduce the observations described in the literature fairly well. Some rules of thumb for XPS and ARPES measurements could be deduced from the simulations. Experimentally, SCEs are investigated by means of ARPES as well as XPS measurements as a function of FEL pulse

  13. Photoelectron spectroscopy at a free-electron laser. Investigation of space-charge effects in angle-resolved and core-level spectroscopy and realizaton of a time-resolved core-level photoemission experiment

    Marczynski-Buehlow, Martin

    2012-01-30

    The free-electron laser (FEL) in Hamburg (FLASH) is a very interesting light source with which to perform photoelectron spectroscopy (PES) experiments. Its special characteristics include highly intense photon pulses (up to 100 J/pulse), a photon energy range of 30 eV to 1500 eV, transverse coherence as well as pulse durations of some ten femtoseconds. Especially in terms of time-resolved PES (TRPES), the deeper lying core levels can be reached with photon energies up to 1500 eV with acceptable intensity now and, therefore, element-specific, time-resolved core-level PES (XPS) is feasible at FLASH. During the work of this thesis various experimental setups were constructed in order to realize angle-resolved (ARPES), core-level (XPS) as well as time-resolved PES experiments at the plane grating monochromator beamline PG2 at FLASH. Existing as well as newly developed systems for online monitoring of FEL pulse intensities and generating spatial and temporal overlap of FEL and optical laser pulses for time-resolved experiments are successfully integrated into the experimental setup for PES. In order to understand space-charge effects (SCEs) in PES and, therefore, being able to handle those effects in future experiments using highly intense and pulsed photon sources, the origin of energetic broadenings and shifts in photoelectron spectra are studied by means of a molecular dynamic N-body simulation using a modified Treecode Algorithm for sufficiently fast and accurate calculations. It turned out that the most influencing parameter is the ''linear electron density'' - the ratio of the number of photoelectrons to the diameter of the illuminated spot on the sample. Furthermore, the simulations could reproduce the observations described in the literature fairly well. Some rules of thumb for XPS and ARPES measurements could be deduced from the simulations. Experimentally, SCEs are investigated by means of ARPES as well as XPS measurements as a function of

  14. Unified interpretation of Hund's first and second rules for 2p and 3p atoms.

    Oyamada, Takayuki; Hongo, Kenta; Kawazoe, Yoshiyuki; Yasuhara, Hiroshi

    2010-10-28

    A unified interpretation of Hund's first and second rules for 2p (C, N, O) and 3p (Si, P, S) atoms is given by Hartree-Fock (HF) and multiconfiguration Hartree-Fock (MCHF) methods. Both methods exactly satisfy the virial theorem, in principle, which enables one to analyze individual components of the total energy E(=T+V(en)+V(ee)), where T, V(en), and V(ee) are the kinetic, the electron-nucleus attraction, and the electron-electron repulsion energies, respectively. The correct interpretation for each of the two rules can only be achieved under the condition of the virial theorem 2T+V=0 by investigating how V(en) and V(ee) interplay to attain the lower total potential energy V(=V(en)+V(ee)). The stabilization of the more stable states for all the 2p and 3p atoms is ascribed to a greater V(en) that is caused by contraction of the valence orbitals accompanied with slight expansion of the core orbitals. The contraction of the valence orbitals for the two rules is a consequence of reducing the Hartree screening of the nucleus at short interelectronic distances. The reduced screening in the first rule is due to a greater amount of Fermi hole contributions in the state with the highest total spin-angular momentum S. The reduced screening in the second rule is due to the fact that two valence electrons are more likely to be on opposite sides of the nucleus in the state with the highest total orbital-angular momentum L. For each of the two rules, the inclusion of correlation does not qualitatively change the HF interpretation, but HF overestimates the energy difference ∣ΔE∣ between two levels being compared. The magnitude of the correlation energy is significantly larger for the lower L states than for the higher L states since two valence electrons in the lower L states are less likely to be on opposite sides of the nucleus. The MCHF evaluation of ∣ΔE∣ is in excellent agreement with experiment. The present HF and MCHF calculations demonstrate the above statements

  15. Precore/basal core promoter mutants and hepatitis B viral DNA levels as predictors for liver deaths and hepatocellular carcinoma

    Myron J Tong; Lawrence M Blatt; Jia-Horng Kao; Jason Tzuying Cheng; William G Corey

    2006-01-01

    AIM: To conduct a retrospective study in 400 chronic hepatitis B patients in order to identify hepatitis B viral factors associated with complications of liver disease or development of hepatocellular carcinoma.METHODS: The mean follow-up time was 83.6 ± 39.6mo. Alpha-fetoprotein test and abdominal ultrasound were used for cancer surveillance. Hepatitis B basal core promoter mutants, precore mutants, genotypes,hepatitis B viral DNA (HBV DNA) level and hepatitis B e antigen (HBeAg) were measured. Univariate analysis and logistic regression were used to assess odds ratios for viral factors related to liver deaths and hepatocellular carcinoma development.RESULTS: During follow-up, 38 patients had liver deaths not related to hepatocellular carcinoma. On multivariate analysis, older age [odds ratio: 95.74 (12.13-891.31);P < 0.0001], male sex [odds ratio: 7.61 (2.20-47.95);P = 0.006], and higher log10 HBV DNA [odds ratio:4.69 (1.16-20.43); P < 0.0001] were independently predictive for these liver related deaths. Also, 31 patients developed hepatocellular carcinoma. Multivariate analysis showed that older age [odds ratio: 26.51 (2.36-381.47);P = 0.007], presence of precore mutants [odds ratio:4.23 (1.53-19.58); P = 0.02] and presence of basal core promoter mutants [odds ratio: 2.93 (1.24-7.57); P =0.02] were independent predictors for progression to hepatocellular carcinoma.CONCLUSION: Our results show that high levels of baseline serum HBV DNA are associated with nonhepatocellular carcinoma-related deaths of liver failure,while genetic mutations in the basal core promoter and precore regions are predictive for development of hepatocellular carcinoma.

  16. Core level regulatory network of osteoblast as molecular mechanism for osteoporosis and treatment

    Zhu, Xiaomei; Li, Jun; Liang, Yuhong; Liu, Tao; Zhu, Yanxia; Zhang, Bingbing; Tan, Shuang; Guo, Huajie; Guan, Shuguang; Ao, Ping; Zhou, Guangqian

    2016-01-01

    To develop and evaluate the long-term prophylactic treatment for chronic diseases such as osteoporosis requires a clear view of mechanism at the molecular and systems level. While molecular signaling pathway studies for osteoporosis are extensive, a unifying mechanism is missing. In this work, we provide experimental and systems-biology evidences that a tightly connected top-level regulatory network may exist, which governs the normal and osteoporotic phenotypes of osteoblast. Specifically, we constructed a hub-like interaction network from well-documented cross-talks among estrogens, glucocorticoids, retinoic acids, peroxisome proliferator-activated receptor, vitamin D receptor and calcium-signaling pathways. The network was verified with transmission electron microscopy and gene expression profiling for bone tissues of ovariectomized (OVX) rats before and after strontium gluconate (GluSr) treatment. Based on both the network structure and the experimental data, the dynamical modeling predicts calcium and glucocorticoids signaling pathways as targets for GluSr treatment. Modeling results further reveal that in the context of missing estrogen signaling, the GluSr treated state may be an outcome that is closest to the healthy state. PMID:26783964

  17. Relativistic effects on the hyperfine structures of 2p4(3P)3p 2Do, 4Do and 4Po in 19F I

    Carette, Thomas; Nemouchi, Messaoud; Li, Jiguang; Godefroid, Michel

    2013-01-01

    The hyperfine interaction constants of the 2p4(3P)3p 2Do_{3/2,5/2}, 4Do_{1/2-7/2} and 4Po_{1/2-5/2} levels in neutral fluorine are investigated theoretically. Large-scale calculations are carried out using the multiconfiguration Hartree-Fock (MCHF) and Dirac-Hartree-Fock (MCDHF) methods. In the framework of the MCHF approach, the relativistic effects are taken into account in the Breit-Pauli approximation using non relativistic orbitals. In the fully relativistic approach, the orbitals are op...

  18. Cooling of Neutron Stars and 3P_2 neutron gap

    Grigorian, H.; Voskresensky, D.N.(National Research Nuclear University (MEPhI), Moscow, 115409, Russia)

    2005-01-01

    We study the dependence of the cooling of isolated neutron stars on the magnitude of the $3P_2$ neutron gap. It is demonstrated that our ``Nuclear medium cooling scenario'' is in favor of a suppressed value of the $3P_2$ neutron gap.

  19. 3p - 3d intershell interaction in Cr

    The photoemission of Cr films deposited under UHV conditions has been investigated in the photon energy range from 30 eV to 230 eV. The 3p - 3d intershell interaction gives rise to a strong maximum in the 3d partial yield above the 3p threshold. (orig.) 891 KBE/orig. 892 RDG

  20. On sulfur core level binding energies in thiol self-assembly and alternative adsorption sites: An experimental and theoretical study

    Jia, Juanjuan [Institut des Sciences Moléculaires d’Orsay, Université-Paris Sud, 91405 Orsay (France); CNRS, UMR 8214, Institut des Sciences Moléculaires d’Orsay, Orsay ISMO, Bâtiment 351, Université Paris Sud, 91405 Orsay (France); Kara, Abdelkader, E-mail: abdelkader.kara@ucf.edu, E-mail: vladimir.esaulov@u-psud.fr [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Pasquali, Luca [Dipartimento di Ingegneria “E. Ferrari,” Università di Modena e Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); IOM-CNR, s.s. 14, Km. 163.5 in AREA Science Park, 34149 Basovizza, Trieste (Italy); Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park 2006 (South Africa); Bendounan, Azzedine; Sirotti, Fausto [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, F-91192 Gif-sur-Yvette Cedex (France); Esaulov, Vladimir A., E-mail: abdelkader.kara@ucf.edu, E-mail: vladimir.esaulov@u-psud.fr [Institut des Sciences Moléculaires d’Orsay, Université-Paris Sud, 91405 Orsay (France); CNRS, UMR 8214, Institut des Sciences Moléculaires d’Orsay, Orsay ISMO, Bâtiment 351, Université Paris Sud, 91405 Orsay (France); IOM-CNR, s.s. 14, Km. 163.5 in AREA Science Park, 34149 Basovizza, Trieste (Italy)

    2015-09-14

    Characteristic core level binding energies (CLBEs) are regularly used to infer the modes of molecular adsorption: orientation, organization, and dissociation processes. Here, we focus on a largely debated situation regarding CLBEs in the case of chalcogen atom bearing molecules. For a thiol, this concerns the case when the CLBE of a thiolate sulfur at an adsorption site can be interpreted alternatively as due to atomic adsorption of a S atom, resulting from dissociation. Results of an investigation of the characteristics of thiol self-assembled monolayers (SAMs) obtained by vacuum evaporative adsorption are presented along with core level binding energy calculations. Thiol ended SAMs of 1,4-benzenedimethanethiol (BDMT) obtained by evaporation on Au display an unconventional CLBE structure at about 161.25 eV, which is close to a known CLBE of a S atom on Au. Adsorption and CLBE calculations for sulfur atoms and BDMT molecules are reported and allow delineating trends as a function of chemisorption on hollow, bridge, and atop sites and including the presence of adatoms. These calculations suggest that the 161.25 eV peak is due to an alternative adsorption site, which could be associated to an atop configuration. Therefore, this may be an alternative interpretation, different from the one involving the adsorption of atomic sulfur resulting from the dissociation process of the S–C bond. Calculated differences in S(2p) CLBEs for free BDMT molecules, SH group sulfur on top of the SAM, and disulfide are also reported to clarify possible errors in assignments.

  1. On sulfur core level binding energies in thiol self-assembly and alternative adsorption sites: An experimental and theoretical study

    Characteristic core level binding energies (CLBEs) are regularly used to infer the modes of molecular adsorption: orientation, organization, and dissociation processes. Here, we focus on a largely debated situation regarding CLBEs in the case of chalcogen atom bearing molecules. For a thiol, this concerns the case when the CLBE of a thiolate sulfur at an adsorption site can be interpreted alternatively as due to atomic adsorption of a S atom, resulting from dissociation. Results of an investigation of the characteristics of thiol self-assembled monolayers (SAMs) obtained by vacuum evaporative adsorption are presented along with core level binding energy calculations. Thiol ended SAMs of 1,4-benzenedimethanethiol (BDMT) obtained by evaporation on Au display an unconventional CLBE structure at about 161.25 eV, which is close to a known CLBE of a S atom on Au. Adsorption and CLBE calculations for sulfur atoms and BDMT molecules are reported and allow delineating trends as a function of chemisorption on hollow, bridge, and atop sites and including the presence of adatoms. These calculations suggest that the 161.25 eV peak is due to an alternative adsorption site, which could be associated to an atop configuration. Therefore, this may be an alternative interpretation, different from the one involving the adsorption of atomic sulfur resulting from the dissociation process of the S–C bond. Calculated differences in S(2p) CLBEs for free BDMT molecules, SH group sulfur on top of the SAM, and disulfide are also reported to clarify possible errors in assignments

  2. Intercombination decay of 3s3p3P10 in Mg I-like Ni and Cu

    The intercombination transition 3s21S0-3s3p 3p10 in Ni16+ and Cu17+ has been studied by beam-foil spectroscopic methods. Decay curve analysis yields lifetime values of (12.0+-1.0) ns and (8.8+-0.6) ns for Ni and Cu in agreement with various predictions. (orig./WL)

  3. Particle distributions in approximately 10(14) 10(16) eV air shower cores at sea level

    Hodson, A. L.; Ash, A. G.; Bull, R. M.

    1985-01-01

    Experimental evidence is reported for fixed distances (0, 1.0, 2.5 and 4.0 m) from the shower centers and for core flattening. The cores become flatter, on average, as the shower size (primary energy) increases. With improved statistics on 4192 cores, the previous results are exactly confirmed.

  4. Increased miR-132-3p expression is associated with chronic neuropathic pain.

    Leinders, M; Üçeyler, N; Pritchard, R A; Sommer, C; Sorkin, L S

    2016-09-01

    Alterations in the neuro-immune balance play a major role in the pathophysiology of chronic neuropathic pain. MicroRNAs (miRNA) can regulate both immune and neuronal processes and may function as master switches in chronic pain development and maintenance. We set out to analyze the role of miR-132-3p, first in patients with peripheral neuropathies and second in an animal model of neuropathic pain. We initially determined miR-132-3p expression by measuring its levels in white blood cells (WBC) of 30 patients and 30 healthy controls and next in sural nerve biopsies of 81 patients with painful or painless inflammatory or non-inflammatory neuropathies based on clinical diagnosis. We found a 2.6 fold increase in miR-132-3p expression in WBC of neuropathy patients compared to healthy controls (panimal model of neuropathic pain, the spared nerve injury model (SNI). For this purpose miR-132-3p expression levels were measured in dorsal root ganglia and spinal cord of rats. Subsequently, miR-132-3p expression was pharmacologically modulated with miRNA antagonists or mimetics, and evoked pain and pain aversion were assessed. Spinal miR-132-3p levels were highest 10days after SNI, a time when persistent allodynia was established (pbehavior in the place escape avoidance paradigm (pbehavior in naïve rats (p<0.001). Taken together these results indicate a pro-nociceptive effect of miR-132-3p in chronic neuropathic pain. PMID:27349406

  5. miR-193a-3p is a potential tumor suppressor in malignant pleural mesothelioma.

    Williams, Marissa; Kirschner, Michaela B; Cheng, Yuen Yee; Hanh, Jacky; Weiss, Jocelyn; Mugridge, Nancy; Wright, Casey M; Linton, Anthony; Kao, Steven C; Edelman, J James B; Vallely, Michael P; McCaughan, Brian C; Cooper, Wendy; Klebe, Sonja; Lin, Ruby C Y; Brahmbhatt, Himanshu; MacDiarmid, Jennifer; van Zandwijk, Nico; Reid, Glen

    2015-09-15

    Malignant pleural mesothelioma (MPM) is an asbestos-induced cancer with poor prognosis that displays characteristic alterations in microRNA expression. Recently it was reported that the expression of a subset of microRNAs can distinguish between MPM and adenocarcinoma of the lung. However, the functional importance of these changes has yet to be investigated. We compared expression of miR-192, miR-193a-3p and the miR-200 family in normal pleura and MPM tumor specimens and found a statistically significant reduction in the levels of miR-193a-3p (3.1-fold) and miR-192 (2.8-fold) in MPM. Transfection of MPM cells with a miR-193a-3p mimic resulted in inhibition of growth and an induction of apoptosis and necrosis in vitro. The growth inhibitory effects of miR-193a-3p were associated with a decrease in MCL1 expression and were recapitulated by RNAi-mediated MCL1 silencing. Targeted delivery of miR-193a-3p mimic using EDV minicells inhibited MPM xenograft tumour growth, and was associated with increased apoptosis. In conclusion, miR-193a-3p appears to have importance in the biology of MPM and may represent a target for therapeutic intervention. PMID:26125439

  6. Protective role of miR-23b-3p in kainic acid-induced seizure.

    Zhan, Lianbo; Yao, Yi; Fu, Huajun; Li, Zhenghui; Wang, Fengpeng; Zhang, Xiaobin; He, Wencan; Zheng, Weihong; Zhang, Yunwu; Zheng, Honghua

    2016-07-01

    Dysregulation of microRNAs has been proposed to contribute toward epilepsy. The miRNA miR-23b-3p has been found to protect against neuronal apoptosis and the production of reactive oxygen species. In this study, we assessed the potential role of miR-23b-3p in the kainic acid (KA)-induced seizure model. We found that miR-23b-3p levels were significantly decreased in the brain cortex of mice and in cultured mouse primary neurons treated with KA. Importantly, supplement of miR-23b-3p agomir by an intacerebroventricular injection alleviated seizure behaviors and abnormal cortical electroencephalogram recordings in KA-treated mice. Together, these results indicate that miR-23b-3p plays a crucial role in suppressing seizure formation in experimental models of epilepsy and that miR-23b-3p supplement may be a potential anabolic strategy for ameliorating seizure. PMID:27232518

  7. Optimization of Extreme Ultraviolet Light Source from High Harmonic Generation for Condensed-Phase Core-Level Spectroscopy

    Lin, Ming-Fu; Verkamp, Max A.; Ryland, Elizabeth S.; Benke, Kristin; Zhang, Kaili; Carlson, Michaela; Vura-Weis, Josh

    2015-06-01

    Extreme ultraviolet (XUV) light source from high-order harmonic generation has been shown to be a powerful tool for core-level spectroscopy. In addition, this light source provides very high temporal resolution (10-18 s to 10-15 s) for time-resolved transient absorption spectroscopy. Most applications of the light source have been limited to the studies of atomic and molecular systems, with technique development focused on optimizing for shorter pulses (i.e. tens of attoseconds) or higher XUV energy (i.e. ~keV range). For the application to general molecular systems in solid and liquid forms, however, the XUV photon flux and stability are highly demanded due to the strong absorption by substrates and solvents. In this case, the main limitation is due to the stability of the high order generation process and the limited bandwidth of the XUV source that gives only discrete even/odd order peaks. Consequently, this results in harmonic artifact noise that overlaps with the resonant signal. In our current study, we utilize a semi-infinite cell for high harmonic generation from two quantum trajectories (i.e. short and long) at over-driven NIR power. This condition, produces broad XUV spectrum without using complicated optics (e.g. hollow-core fibers and double optical gating). This light source allows us to measure the static absorption spectrum of the iron M-edge from a Fe(acac)3 molecular solid film, which shows a resonant feature of 0.01 OD (~2.3% absorption). Moreover, we also investigate how sample roughness affects the static absorption spectrum. We are able to make smooth solar cell precursor materials (i.e. PbI2 and PbBr2) by spin casting and observe iodine (50 eV) and bromine (70 eV) absorption edges in the order of 0.05 OD with minimal harmonic artifact noise.

  8. miR-1207-3p Is a Novel Prognostic Biomarker of Prostate Cancer.

    Das, Dibash K; Osborne, Joseph R; Lin, Hui-Yi; Park, Jong Y; Ogunwobi, Olorunseun O

    2016-06-01

    MicroRNAs (miRNAs) have been found to be dysregulated in prostate cancer (PCa). In this study, we investigated if miR-1207-3p is capable of distinguishing between indolent and aggressive PCa and if it contributes to explaining the disproportionate aggressiveness of PCa in men of African ancestry (moAA). A total of 404 patients with primary adenocarcinoma of the prostate were recruited between 1988 and 2003 at the Moffitt Cancer Center, Tampa, FL, USA. Patient clinicopathological features and demographic characteristics such as race were identified. RNA samples from 404 postprostatectomy prostate tumor tissue samples were analyzed by real-time quantitative reverse transcription polymerase chain reaction for the mRNA expression of miR-1207-3p. miR-1207-3p expression in PCa that resulted in overall death or PCa-specific death is significantly higher than in PCa cases that did not. The same positive correlation holds true for other clinical characteristics such as biochemical recurrence, Gleason score, clinical stage, and prostate-specific antigen level. Furthermore, miR-1207-3p expression was significantly less in moAA in comparison to Caucasian men. We also evaluated whether miR-1207-3p is associated with clinical outcomes adjusted for age at diagnosis and tumor stage in the modeling. Using competing risk regression, the PCa patients with a high miR-1207-3p expression (≥6 vs 3) had a high risk to develop PCa recurrence (hazard rate = 2.5, P < .001) adjusting for age at diagnosis and tumor stage. In conclusion, miR-1207-3p is a promising novel prognostic biomarker for PCa. Furthermore, miR-1207-3p may also be important in explaining the disproportionate aggressiveness of PCa in moAA. PMID:27267842

  9. MiR-373-3p Promotes Invasion and Metastasis of Lung Adenocarcinoma Cells

    Aibing WU

    2015-07-01

    Full Text Available Background and objective Lung cancer is the leading cause of cancer-related deaths worldwide, and metastasis is the major cause of death in lung cancer patients. MiR-373 is closely associated with invasion and metastasis in other tumor cells. This study explored the expression of miR-373-3p in non-small cell lung cancer (NSCLC and its effect on the invasive and metastatic capabilities of lung adenocarcinoma cells, as well as their mechanisms of action. Methods The expression of miR-373-3p in NSCLC tissues and lung adenocarcinoma cell lines was detected by quantitative reverse transcription polymerase chain reaction. The roles of miR-373-3p in regulating lung adenocarcinoma cell invasion and metastatic properties were analyzed with miR-373-3p mimic/inhibitor-transfected cells via Transwell chamber assay. Matrix metalloproteinase MMP-9 and MMP-14 protein levels were detected by Western blot in lung cancer cells after transfection. Results MiR-373-3p was upregulated in 51 NSCLC tissues and 5 NSCLC cell lines. Gain-of-function and loss-of-function studies showed that overexpression of miR-373-3p promoted H1299 cell migration and invasion, which resulted in upregulation of MMP-9 and MMP-14. By contrast, miR-373-3p knockdown inhibited these processes in A549 cells and downregulated the expression of MMP-9 and MMP-14. Conclusion Our results demonstrated that miR-373-3p participated in the invasion and metastasis of lung adenocarcinoma cells, partly by upregulation of MMP-9 and MMP-14.

  10. Preindustrial atmospheric ethane levels inferred from polar ice cores: A constraint on the geologic sources of atmospheric ethane and methane

    Nicewonger, Melinda R.; Verhulst, Kristal R.; Aydin, Murat; Saltzman, Eric S.

    2016-01-01

    Ethane levels were measured in air extracted from Greenland and Antarctic ice cores ranging in age from 994 to 1918 Common Era (C.E.) There is good temporal overlap between the two data sets from 1600 to 1750 C.E. with ethane levels stable at 397 ± 28 parts per trillion (ppt) (±2 standard error (s.e.)) over Greenland and 103 ± 9 ppt over Antarctica. The observed north/south interpolar ratio of ethane (3.9 ± 0.1, 1σ) implies considerably more ethane emissions in the Northern Hemisphere than in the Southern Hemisphere, suggesting geologic ethane sources contribute significantly to the preindustrial ethane budget. Box model simulations based on these data constrain the global geologic emissions of ethane to 2.2-3.5 Tg yr-1 and biomass burning emissions to 1.2-2.5 Tg yr-1 during the preindustrial era. The results suggest biomass burning emissions likely increased since the preindustrial period. Biomass burning and geologic outgassing are also sources of atmospheric methane. The results place constraints on preindustrial methane emissions from these sources.

  11. Relativistic configuration-interaction calculation of energy levels of core-excited states in lithium-like ions: argon through krypton

    Yerokhin, V. A.; Surzhykov, A.

    2012-01-01

    Large-scale relativistic configuration-interaction calculation of energy levels of core-excited states of lithium-like ions is presented. Quantum electrodynamic, nuclear recoil, and frequency-dependent Breit corrections are included in the calculation. The approach is consistently applied for calculating all $n=2$ core-excited states for all lithium-like ions starting from argon ($Z = 18$) and ending with krypton ($Z = 36$). The results obtained are supplemented with systematical estimations ...

  12. MicroRNA-409-3p inhibits osteosarcoma cell migration and invasion by targeting catenin-δ1.

    Wu, Shifeng; Du, Xinjie; Wu, Manwu; Du, Hechun; Shi, Xiaoliang; Zhang, Tao

    2016-06-10

    Osteosarcoma is the most common primary bone cancer which is associated with early metastatic potential and poor prognosis. However, the molecular mechanisms underlying osteosarcoma progression are not well characterized. Here, we investigated the role of miR-409-3p in osteosarcoma metastasis. Osteosarcoma tissue showed decreased expression of miR-409-3p compared to adjacent non-tumorous tissue. The expression level of miR-409-3p was negatively correlated with osteosarcoma metastasis. Overexpression of miR-409-3p in osteosarcoma cells (U2OS) inhibited cell migration and invasion. Bioinformatics analysis showed that catenin-δ1 (CTNND1, p120-catenin) is a direct target of miR-409-3p. Overexpression of miR-409-3p repressed the expression of catenin-δ1 in U2OS cells at both mRNA and protein levels. Meanwhile, miR-409-3p repressed the activity of luciferase reporter containing the 3'-untranslated region (3'UTR) of CTNND1 gene. Furthermore, expression of catenin-δ1 rescued the inhibitory effect of miR-409-3p on cell migration and invasion. Altogether, these results indicated that miR-409-3p targets catenin-δ1 to repress osteosarcoma metastasis. PMID:26992637

  13. miR-342-3p affects hepatocellular carcinoma cell proliferation via regulating NF-κB pathway

    Zhao, Liang; Zhang, Yubao, E-mail: zhyb880077@sina.com

    2015-02-13

    Recent research indicates that non-coding microRNAs (miRNAs) help regulate basic cellular processes in many types of cancer cells. We hypothesized that overexpression of miR-342-3p might affect proliferation of hepatocellular carcinoma (HCC) cells. After confirming overexpression of miR-342-3p with qRT-PCR, MTT assay showed that HCC cell proliferation was significantly inhibited by miR-342-3p, and that it significantly decreased BrdU-positive cell proliferation by nearly sixfold. Searching for targets using three algorithms we found that miR-342-3p is related to the NF-κB pathway and luciferase assay found that IKK-γ, TAB2 and TAB3 are miR-342-3p target genes. Results of western blot on extracted nuclear proteins of HepG2 and HCT-116 cells showed that miR-342-3p reduced and miR-342-3p-in increased p65 nuclear levels and qRT-PCR found that NF-κB pathway downstream genes were downregulated by miR-342-3p and upregulated by miR-342-3p-in, confirming that miR-342 targets NF-κB pathway. Overexpression of Ikk-γ, TAB2 and TAB3 partially rescued HCC cells proliferation inhibited by miR-342-3p. Using the GSE54751 database we evaluated expression from 10 HCC samples, which strongly suggested downregulation of miR-342-3p and we also found inverse expression between miR-342-3p and its targets IKK-γ, TAB2 and TAB3 from 71 HCC samples. Our results show that miR-342-3p has a significant role in HCC cell proliferation and is suitable for investigation of therapeutic targets. - Highlights: • MiR-342-3p suppresses hepatocellular carcinoma cell proliferation. • MiR-342-3p targets IKK-γ, TAB2 and TAB3 genes. • MiR-342-3p downregulates NF-kB signaling pathway. • MiR-342-3p is downregulated in clinical hepatocellular carcinoma samples. • The expression of miR-342-3p and its target gene is inversely related.

  14. miR-342-3p affects hepatocellular carcinoma cell proliferation via regulating NF-κB pathway

    Recent research indicates that non-coding microRNAs (miRNAs) help regulate basic cellular processes in many types of cancer cells. We hypothesized that overexpression of miR-342-3p might affect proliferation of hepatocellular carcinoma (HCC) cells. After confirming overexpression of miR-342-3p with qRT-PCR, MTT assay showed that HCC cell proliferation was significantly inhibited by miR-342-3p, and that it significantly decreased BrdU-positive cell proliferation by nearly sixfold. Searching for targets using three algorithms we found that miR-342-3p is related to the NF-κB pathway and luciferase assay found that IKK-γ, TAB2 and TAB3 are miR-342-3p target genes. Results of western blot on extracted nuclear proteins of HepG2 and HCT-116 cells showed that miR-342-3p reduced and miR-342-3p-in increased p65 nuclear levels and qRT-PCR found that NF-κB pathway downstream genes were downregulated by miR-342-3p and upregulated by miR-342-3p-in, confirming that miR-342 targets NF-κB pathway. Overexpression of Ikk-γ, TAB2 and TAB3 partially rescued HCC cells proliferation inhibited by miR-342-3p. Using the GSE54751 database we evaluated expression from 10 HCC samples, which strongly suggested downregulation of miR-342-3p and we also found inverse expression between miR-342-3p and its targets IKK-γ, TAB2 and TAB3 from 71 HCC samples. Our results show that miR-342-3p has a significant role in HCC cell proliferation and is suitable for investigation of therapeutic targets. - Highlights: • MiR-342-3p suppresses hepatocellular carcinoma cell proliferation. • MiR-342-3p targets IKK-γ, TAB2 and TAB3 genes. • MiR-342-3p downregulates NF-kB signaling pathway. • MiR-342-3p is downregulated in clinical hepatocellular carcinoma samples. • The expression of miR-342-3p and its target gene is inversely related

  15. Chromosome 3p alterations in pancreatic endocrine neoplasia

    Amato, Eliana; Barbi, Stefano; Malpeli, Giorgio; Bersani, Samantha; Pelosi, Giuseppe; Capelli, Paola

    2010-01-01

    Pancreatic endocrine tumors (PET) are rare neoplasms classified as functioning (F-PET) or non-functioning (NF-PET) according to the presence of a clinical syndrome due to hormonal hypersecretion. PETs show variable degrees of clinical aggressiveness and loss of chromosome 3p has been suggested to be associated with an advanced stage of disease. We assessed chromosome 3p copy number in 113 primary PETs and 32 metastases by fluorescence in situ hybridization (FISH) using tissue microarrays. The series included 56 well-differentiated endocrine tumors (WDET), 62 well-differentiated endocrine carcinomas (WDEC), and 6 poorly differentiated endocrine carcinomas (PDEC). Chromosome 3p alterations were found in 23/113 (20%) primary tumors, with losses being predominant over gains (14% vs. 6%). Loss of 3p was found in 5/55 (9%) WDET, 11/52 (21%) WDEC, and never in PDEC. Gains of 3p were detected in 4/55 (7%) WDET, no WDEC, but notably in 3/6 (50%) PDEC (OR 23.6; P = 0.003). Metastases were more frequently monosomic for 3p compared to primary tumors (OR 3.6; P = 0.005). Monosomy was significantly associated with larger tumor size, more advanced tumor stage, and metastasis. No association was found with survival. Chromosome 3p copy number alterations are frequent events in advanced stage PET, with gains prevailing in PDEC while losses are more frequent in WDEC, supporting the view that a specific pattern of alterations are involved in these diverse disease subtypes. PMID:20981439

  16. O- and H-induced surface core level shifts on Ru(0001): prevalence of the additivity rule

    In previous work on adsorbate-induced surface core level shifts (SCLSs), the effects caused by O atom adsorption on Rh(111) and Ru(0001) were found to be additive: the measured shifts for first-layer Ru atoms depended linearly on the number of directly coordinated O atoms. Density-functional theory calculations quantitatively reproduced this effect, allowed separation of initial- and final-state contributions, and provided an explanation in terms of a roughly constant charge transfer per O atom. We have now conducted similar measurements and calculations for three well-defined adsorbate and coadsorbate layers containing O and H atoms: (1 x 1)-H, (2 x 2)-(O+H) and (2 x 2)-(O+3H) on Ru(0001). As H is stabilized in fcc sites in the prior two structures and in hcp sites in the latter, this enables us to not only study coverage and coadsorption effects on the adsorbate-induced SCLSs, but also the sensitivity to similar adsorption sites. Remarkably good agreement is obtained between experiment and calculations for the energies and geometries of the layers, as well as for all aspects of the SCLS values. The additivity of the next-neighbor adsorbate-induced SCLSs is found to prevail even for the coadsorbate structures. While this confirms the suggested use of SCLSs as fingerprints of the adsorbate configuration, their sensitivity is further demonstrated by the slightly different shifts unambiguously determined for H adsorption in either fcc or hcp hollow sites.

  17. Core-level photoelectron study of Si(1 1 1) sq root 7x sq root 3-(Pb, Sn) surface

    Soda, K; Takada, T; Yoshimoto, O; Kato, M; Yagi, S; Morita, K; Kamada, M

    2003-01-01

    The Sn 4d and Pb 5d core-level photoelectron spectra have been studied in order to clarify their bonding properties and atomic arrangement on a Si(1 1 1) sq root 7x sq root 3-(Pb, Sn) surface, which is formed by the coadsorption of 0.4 ML Pb and 0.4 ML Sn and shows two kinds of bright spots in the scanning tunneling microscopic (STM) images: (A) those aligned zigzag on the T sub 1 site and (B) those on the T sub 1 and H sub 3 sites along the [1 1 -2] direction. The Pb 5d spectrum shows a single spin-orbit-split feature with weak tailing towards the high binding energy side, while the Sn 4d spectrum exhibits shoulder structures at the high binding energy side of the main peaks. This definitely indicates at least two different Sn-Si bonds or inequivalent Sn adsorbing sites and single bond or site for Pb. Thus the spots A at the T sub 1 site and those B at the T sub 1 and H sub 3 sites in the STM images are ascribed to Pb and Sn adatoms, respectively. The formation process of this surface will be also discussed ...

  18. Identification of miR-508-3p and miR-509-3p that are associated with cell invasion and migration and involved in the apoptosis of renal cell carcinoma

    Zhai, Qingna [Department of Clinical Laboratory, Peking University Shenzhen Hospital, Guangdong (China); Shantou University Medical College, Guangdong (China); Zhou, Liang [Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Guangdong (China); Zhao, Chunjuan [Department of Clinical Laboratory, Peking University Shenzhen Hospital, Guangdong (China); Shantou University Medical College, Guangdong (China); Wan, Jun [Section of Biochemistry and Cell Biology, Division of Life Science, The Hong Kong University of Science and Technology (Hong Kong); Yu, Zhendong, E-mail: zhendongyu66@hotmail.com [Department of Clinical Laboratory, Peking University Shenzhen Hospital, Guangdong (China); Guo, Xin; Qin, Jie; Chen, Jing [Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Guangdong (China); Lu, Ruijing [Department of Clinical Laboratory, Peking University Shenzhen Hospital, Guangdong (China); Shantou University Medical College, Guangdong (China)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer Previous method was the second-generation sequencing technology. Black-Right-Pointing-Pointer miR-508-3p and miR-509-3p were significantly down-regulated in RCC tissues. Black-Right-Pointing-Pointer They can inhibit cell proliferation and migration and promote cell apoptosis. Black-Right-Pointing-Pointer The expression of miR-508-3p was significantly decreased in RCC patients plasma. Black-Right-Pointing-Pointer miR-508-3p may be a novel diagnostic marker of RCC. -- Abstract: MicroRNAs (miRNAs) have emerged as powerful regulators of multiple processes linked to human cancer, including cell apoptosis, proliferation and migration, suggesting that the regulation of miRNA function could play a critical role in cancer progression. Recent studies have found that human serum/plasma contains stably expressed miRNAs. If they prove indicative of disease states, miRNAs measured from peripheral blood samples may be a source for routine clinical detection of cancer. Our studies showed that both miR-508-3p and miR-509-3p were down-regulated in renal cancer tissues. The level of miR-508-3p but not miR-509-3p in renal cell carcinoma (RCC) patient plasma demonstrated significant differences from that in control plasma. In addition, the overexpression of miR-508-3p and miR-509-3p suppressed the proliferation of RCC cells (786-0), induced cell apoptosis and inhibited cell migration in vitro. Our data demonstrated that miR-508-3p and miR-509-3p played an important role as tumor suppressor genes during tumor formation and that they may serve as novel diagnostic markers for RCC.

  19. Identification of miR-508-3p and miR-509-3p that are associated with cell invasion and migration and involved in the apoptosis of renal cell carcinoma

    Highlights: ► Previous method was the second-generation sequencing technology. ► miR-508-3p and miR-509-3p were significantly down-regulated in RCC tissues. ► They can inhibit cell proliferation and migration and promote cell apoptosis. ► The expression of miR-508-3p was significantly decreased in RCC patients plasma. ► miR-508-3p may be a novel diagnostic marker of RCC. -- Abstract: MicroRNAs (miRNAs) have emerged as powerful regulators of multiple processes linked to human cancer, including cell apoptosis, proliferation and migration, suggesting that the regulation of miRNA function could play a critical role in cancer progression. Recent studies have found that human serum/plasma contains stably expressed miRNAs. If they prove indicative of disease states, miRNAs measured from peripheral blood samples may be a source for routine clinical detection of cancer. Our studies showed that both miR-508-3p and miR-509-3p were down-regulated in renal cancer tissues. The level of miR-508-3p but not miR-509-3p in renal cell carcinoma (RCC) patient plasma demonstrated significant differences from that in control plasma. In addition, the overexpression of miR-508-3p and miR-509-3p suppressed the proliferation of RCC cells (786-0), induced cell apoptosis and inhibited cell migration in vitro. Our data demonstrated that miR-508-3p and miR-509-3p played an important role as tumor suppressor genes during tumor formation and that they may serve as novel diagnostic markers for RCC.

  20. Stratigraphic analysis of lake level fluctuations in Lake Ohrid: an integration of high resolution hydro-acoustic data and sediment cores

    Lindhorst, K.; H. Vogel; S. Krastel; Wagner, B.; Hilgers, A.; Zander, A.; Schwenk, T.; Wessels, M.; Daut, G.

    2010-01-01

    Ancient Lake Ohrid is a steep sided, oligotrophic, karst lake of likely Pliocene age and often referred to as a hotspot of endemic biodiversity. This study aims on tracing significant lake level fluctuations at Lake Ohrid using high-resolution acoustic data in combination with lithological, geochemical, and chronological information from two sediment cores recovered from sub-aquatic terrace levels at ca. 32 and 55 m. According to our data, significant lake level fluctuations with prominent lo...

  1. Size-tunable, hexagonal plate-like Cu3P and Janus-like Cu-Cu3P nanocrystals.

    De Trizio, Luca; Figuerola, Albert; Manna, Liberato; Genovese, Alessandro; George, Chandramohan; Brescia, Rosaria; Saghi, Zineb; Simonutti, Roberto; Van Huis, Marijn; Falqui, Andrea

    2012-01-24

    We describe two synthesis approaches to colloidal Cu(3)P nanocrystals using trioctylphosphine (TOP) as phosphorus precursor. One approach is based on the homogeneous nucleation of small Cu(3)P nanocrystals with hexagonal plate-like morphology and with sizes that can be tuned from 5 to 50 nm depending on the reaction time. In the other approach, metallic Cu nanocrystals are nucleated first and then they are progressively phosphorized to Cu(3)P. In this case, intermediate Janus-like dimeric nanoparticles can be isolated, which are made of two domains of different materials, Cu and Cu(3)P, sharing a flat epitaxial interface. The Janus-like nanoparticles can be transformed back to single-crystalline copper particles if they are annealed at high temperature under high vacuum conditions, which makes them an interesting source of phosphorus. The features of the Cu-Cu(3)P Janus-like nanoparticles are compared with those of the striped microstructure discovered more than two decades ago in the rapidly quenched Cu-Cu(3)P eutectic of the Cu-P alloy, suggesting that other alloy/eutectic systems that display similar behavior might give origin to nanostructures with flat, epitaxial interface between domains of two diverse materials. Finally, the electrochemical properties of the copper phosphide plates are studied, and they are found to be capable of undergoing lithiation/delithiation through a displacement reaction, while the Janus-like Cu-Cu(3)P particles do not display an electrochemical behavior that would make them suitable for applications in batteries. PMID:22136519

  2. Au Nanowire-Striped Cu3P Platelet Photoelectrocatalysts.

    Dutta, Anirban; Samantara, Aneeya K; Adhikari, Samrat Das; Jena, Bikash Kumar; Pradhan, Narayan

    2016-03-17

    A stripy pattern of continuous epitaxial growth of thin Au nanowires on plasmonic Cu3P platelets is reported. The obtained Au-Cu3P heterostructures retain their wide area interfacial heterojunction, which is typically not observed in metal-semiconductor heterostructures. This is performed by phosphine-mediated in situ reduction of Au ions on specific facets of Cu3P platelets. The intriguing stripy movements of nanowires are regulated by strong surface binding ligands. Because this is a dual plasmon heterostructure with wide visible absorption window, these are further explored as a photoelectrocatalyst for efficient hole transfer and sensing of an important biomolecule, nicotinamide adenine dinucleotide (NADH). The observed anodic photocurrent was 30 times higher in the presence of NADH, and this proves that the heterostructured material is an ideal photosenser and an efficient catalyst for solar energy conversion. PMID:26938025

  3. Synthesization of the Ar VIII 3s-3p beam-foil decay curve

    The beam-foil decay curve for the 3s-3p transition in Ar VIII has been simulated from experimentally determined relative initial level populations and transition probabilities calculated in the numerical Coulomb approximation. Good agreement is observed between simulated and measured decay curves. A discussion of the simulation is given. (Auth.)

  4. Misregulation of Scm3p/HJURP causes chromosome instability in Saccharomyces cerevisiae and human cells.

    Prashant K Mishra

    2011-09-01

    Full Text Available The kinetochore (centromeric DNA and associated proteins is a key determinant for high fidelity chromosome transmission. Evolutionarily conserved Scm3p is an essential component of centromeric chromatin and is required for assembly and function of kinetochores in humans, fission yeast, and budding yeast. Overexpression of HJURP, the mammalian homolog of budding yeast Scm3p, has been observed in lung and breast cancers and is associated with poor prognosis; however, the physiological relevance of these observations is not well understood. We overexpressed SCM3 and HJURP in Saccharomyces cerevisiae and HJURP in human cells and defined domains within Scm3p that mediate its chromosome loss phenotype. Our results showed that the overexpression of SCM3 (GALSCM3 or HJURP (GALHJURP caused chromosome loss in a wild-type yeast strain, and overexpression of HJURP led to mitotic defects in human cells. GALSCM3 resulted in reduced viability in kinetochore mutants, premature separation of sister chromatids, and reduction in Cse4p and histone H4 at centromeres. Overexpression of CSE4 or histone H4 suppressed chromosome loss and restored levels of Cse4p at centromeres in GALSCM3 strains. Using mutant alleles of scm3, we identified a domain in the N-terminus of Scm3p that mediates its interaction with CEN DNA and determined that the chromosome loss phenotype of GALSCM3 is due to centromeric association of Scm3p devoid of Cse4p/H4. Furthermore, we determined that similar to other systems the centromeric association of Scm3p is cell cycle regulated. Our results show that altered stoichiometry of Scm3p/HJURP, Cse4p, and histone H4 lead to defects in chromosome segregation. We conclude that stringent regulation of HJURP and SCM3 expression are critical for genome stability.

  5. Holocene sea-level determination relative to the Australian continent: U/Th (TIMS) and 14C (AMS) dating of coral cores from the Abrolhos Islands

    Eisenhauer, A.; Wasserburg, G. J.; Chen, J. H.; Bonani, G.; Collins, L. B.; Zhu, Z. R.; Wyrwoll, K. H.

    1993-02-01

    U/Th (TIMS) and 14C (AMS) measurements are presented from two coral cores from the Easter group of the Houtman Abrolhos Islands between 28°S and 29°S on the western continental margin of Australia. The U/Th measurements on the Morley core from Morley Island cover a depth interval from 0.2 m above present sea level to 24.4 m below present sea level and comprise eleven samples. The ages vary between 6320 ± 50 a, at 0.2 m above sea level, and 9809 ± 95 a, at 24.4 m below sea level (all errors are 2σ). The mean growth rate is 7.1 ± 0.9 m/ka. The 14C dates of selected Morley core corals show that the 14C ages are ˜ 1000 a younger than their corresponding U/Th ages, which agrees with previous results. The main purpose of our 14C measurements is to be able to compare them precisely with other coral cores where no U/Th measurements are available. The U/Th measurements of the Suomi core from Suomi Island cover a depth interval from 0.05 m to 14.2 m below present sea level and consist of four samples. The ages vary between 4671 ± 40 a, at 0.05 m below sea level, and 7102 ± 82 a, at 14.2 m below sea level, with a mean growth rate of 5.8 ± 0.2 m/ka. The growth history of both cores is explained by a simple model in which the growth rates of the Morley core can be interpreted as reflecting local rates of sea level rise, whereas the Suomi core is interpreted as reflecting lateral growth during the past ˜ 6000 a. Our results indicate that sea level relative to the western margins of the Australian continent was about 24 m lower than present at about 9800 a B.P. ( 14C gives a date of 8500 a B.P.). Sea level then rose and reached a highstand, slightly higher than the present position at about 6300 a B.P ( 14C date: 5500 a). This highstand declined but was still higher than present at 4600 a B.P. This is in agreement with previous observations along the Australian coastal margins and with observations from the Huon peninsula (Papua New Guinea). Our results are very

  6. A new form of Ca3P2 with a ring of Dirac nodes

    We report the synthesis and crystal structure of a new high-temperature form of Ca3P2. The crystal structure was determined through Rietveld refinements of synchrotron powder x-ray diffraction data. This form of Ca3P2 has a crystal structure of the hexagonal Mn5Si3 type, with a Ca ion deficiency compared to the ideal 5:3 stoichiometry. This yields a stable, charge-balanced compound of Ca2+ and P3−. We also report the observation of a secondary hydride phase, Ca5P3H, which again is a charge-balanced compound. The calculated band structure of Ca3P2 indicates that it is a three-dimensional Dirac semimetal with a highly unusual ring of Dirac nodes at the Fermi level. The Dirac states are protected against gap opening by a mirror plane in a manner analogous to what is seen for graphene

  7. Ba 4d core-level spectroscopy in the YBa2Cu3O6.9 high-Tc superconductor: Existence of a surface-shifted component

    Two sets of spin-orbit split Ba 4d core-level photoemission peaks were observed in a crystal of YBa2Cu3O6.9. From constant final-state measurements taken as a function of kinetic energy, the low-binding-energy doublet is identified as a surface component. Possible origins of the surface shift are discussed

  8. Stratigraphic analysis of lake level fluctuations in Lake Ohrid: an integration of high resolution hydro-acoustic data and sediment cores

    Lindhorst, K.; H. Vogel; S. Krastel; Wagner, B.; Hilgers, A.; Zander, A.; Schwenk, T.; Wessels, M.; Daut, G.

    2010-01-01

    Ancient Lake Ohrid is a steep-sided, oligotrophic, karst lake that was tectonically formed most likely within the Pliocene and often referred to as a hotspot of endemic biodiversity. This study aims on tracing significant lake level fluctuations at Lake Ohrid using high-resolution acoustic data in combination with lithological, geochemical, and chronological information from two sediment cores recovered from sub-aquatic terrace levels at ca. 32 and 60 m water depth. According t...

  9. Stratigraphic analysis of lake level fluctuations in Lake Ohrid: an integration of high resolution hydro-acoustic data and sediment cores

    Lindhorst, K.; Vogel, Hendrik; S. Krastel; Wagner, B.; Hilgers, A.; Zander, A.; Schwenk, T.; Wessels, M.; Daut, G.

    2010-01-01

    Abstract. Ancient Lake Ohrid is a steep-sided, oligotrophic, karst lake that was tectonically formed most likely within the Pliocene and often referred to as a hotspot of endemic biodiversity. This study aims on tracing significant lake level fluctuations at Lake Ohrid using high-resolution acoustic data in combination with lithological, geochemical, and chronological information from two sediment cores recovered from sub-aquatic terrace levels at ca. 32 and 60m water dep...

  10. Application of assemblies of in-core instruments of the emergency process instrumentation system. The reactor pressure vessel coolant level sensor in Pressurized-Water Reactors

    Using as an example the coolant level sensor within SVRD.KNITU assembly, the report deals with a possibility of using assemblies of in-core instruments (SVRD), which ensure the application of in-core monitoring system in normal operation conditions, in the emergency process instrumentation system. Assemblies portrayed in the present report are designed and operated in the Russian-built pressurized water reactors and uranium-graphite channel reactors. However, the philosophy of their design is such that an assembly can be easily adapted to reactors of other types

  11. Dsj meson decay in the C3P0 model

    Full text. Fock-Tani is a field theory formalism appropriated for the simultaneous treatment of composite particles and their constituents. The formalism was originally developed for the treatment of problems in atomic physics and it was extended later on to the treatment of problems on hadron physics. In the Fock-Tani formalism one starts with the Fock representation of the system using field operators of elementary constituents which satisfy canonical (anti) commutation relations. Composite-particle field operators are linear combinations of the elementary-particle operators and do not generally satisfy canonical (anti) commutation relations. 'Ideal' field operators acting on an enlarged Fock space are then introduced in close correspondence with the composite ones. Next, a given unitary transformation, which transforms the single composite states into single ideal states, is introduced. Application of the unitary operator on the microscopic Hamiltonian, or on other hermitian operators expressed in terms of the elementary constituent field operators, gives equivalent operators which contain the ideal field operators. The effective Hamiltonian in the new representation has a clear physical interpretation in terms of the processes it describes. Since all field operators in the new representation satisfy canonical (anti)commutation relations, the standard methods of quantum field theory can then be readily applied. For a long time the pair creation models for strong hadronic decays have been formulated. The 3P0 model is typical decay model which considers only OZI-allowed strong decays. The 3P0 model considers a quark-antiquark par creation in the presence of the initial state meson. The quark-antiquark par is created with the vacuum quantum numbers. This model can also be obtained from the non-relativistic limit of the pair creation Hamiltonian. Applying the Fock-Tani transformation to the pair creation Hamiltonian produces the characteristic expansion in powers of

  12. Resonant inverse photoemission study of late transition metals at 3p absorption edge

    Full text: Resonant inverse photoemission spectra (RIPES) of late transition metals (TM) were observed near TM 3p absorption edge. The RIPES spectra of polycrystalline Co, Ni and Cu, as well as single crystal Ni, were observed. Figure 1 shows resonant IPES spectra of polycrystalline Co, Ni and Cu, which were prepared by evaporation. These spectra ware excited by energy above 3p absorption edge (off-resonance). Since a core hole is created by these energies, TM 3d → 3p fluorescence peak is observed in each spectrum at high energy, which is indicated by vertical bars. The main peak just above EF is TM 3d structure, while TM 4sp is observed at 10 ∼ 15 eV. In resonant spectra, the 3d structure changes its intensity, while the 4sp structure does not. In case of Ni metal, satellite structures are also observed at about 2 and 4 eV. From a calculation by Tanaka and Jo, which is based on the Anderson impurity model, the observation of satellite structures suggests the 10 ∼ 20 % 3d8 in ground state The RIPES spectra in this study give us a direct evidence of 3d8 component in Ni metal

  13. MicroRNA-490-3p inhibits proliferation of A549 lung cancer cells by targeting CCND1

    Highlights: • We examined the level of miR-490-3p in A549 lung cancer cells compared with normal bronchial epithelial cell line. • We are the first to show the function of miR-490-3p in A549 lung cancer cells. • We demonstrate CCND1 may be one of the targets of miR-490-3p. - Abstract: MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate the translation of messenger RNAs by binding their 3′-untranslated region (3′UTR). In this study, we found that miR-490-3p is significantly down-regulated in A549 lung cancer cells compared with the normal bronchial epithelial cell line. To better characterize the role of miR-490-3p in A549 cells, we performed a gain-of-function analysis by transfecting the A549 cells with chemically synthesized miR-490-3P mimics. Overexpression of miR-490-3P evidently inhibits cell proliferation via G1-phase arrest. We also found that forced expression of miR-490-3P decreased both mRNA and protein levels of CCND1, which plays a key role in G1/S phase transition. In addition, the dual-luciferase reporter assays indicated that miR-490-3P directly targets CCND1 through binding its 3′UTR. These findings indicated miR-490-3P could be a potential suppressor of cellular proliferation

  14. Electron-hole correlation effects in core-level spectroscopy probed by the resonant inelastic soft x-ray scattering map of C{sub 60}

    Weinhardt, L.; Fuchs, O.; Schoell, A.; Reinert, F. [Universitaet Wuerzburg, Experimentelle Physik VII, Am Hubland, 97074 Wuerzburg (Germany); Batchelor, D.; Umbach, E. [Karlsruhe Institute of Technology, D-76021 Karlsruhe (Germany); Baer, M. [Solar Energy Research, Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH (HZB), 14109 Berlin (Germany); Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003 (United States); Blum, M. [Universitaet Wuerzburg, Experimentelle Physik VII, Am Hubland, 97074 Wuerzburg (Germany); Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003 (United States); Denlinger, J. D.; Yang, W. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Heske, C. [Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003 (United States)

    2011-09-14

    We have employed a unique spectroscopic approach, a resonant inelastic soft x-ray scattering (RIXS) map, to identify and separate electron-hole correlation effects in core-level spectroscopy. With this approach, we are able to derive a comprehensive picture of the electronic structure, separating ground state properties (such as the HOMO-LUMO separation) from excited state properties (such as the C 1s core-exciton binding energy of C{sub 60}). In particular, our approach allows us to determine the difference between core- and valence exciton binding energies in C{sub 60}[0.5 ({+-}0.2) eV]. Furthermore, the RIXS map gives detailed insight into the symmetries of the intermediate and final states of the RIXS process.

  15. Configuration interaction calculations of positron binding to Be(3P )

    The configuration interaction method is applied to investigate the possibility of positron binding to the metastable beryllium (1s22s2p 3P ) state. The largest calculation obtained an estimated energy that was unstable by 0.00014 Hartree with respect to the Ps + Be+(2s) lowest dissociation channel. It is likely that positron binding to parent states with non-zero angular momentum is inhibited by centrifugal barriers

  16. Model core potentials for studies of scalar-relativistic effects and spin-orbit coupling at Douglas-Kroll level. I. Theory and applications to Pb and Bi.

    Zeng, Tao; Fedorov, Dmitri G; Klobukowski, Mariusz

    2009-09-28

    A theory of model core potentials that can treat spin-orbit-coupling (SOC) effects at the level of Douglas-Kroll formalism has been developed. By storing the damping effect of kinematic operator in the Douglas-Kroll spin-orbit operator into an additional set of basis set contraction coefficients, the Breit-Pauli spin-orbit code in the GAMESS-US program was successfully used to perform Douglas-Kroll spin-orbit calculations. It was found that minute errors in the radial functions of valence orbitals lead to large errors in the spin-orbit energy levels and thus fitting the radial part of the spin-orbit matrix elements is necessary in model core potential parametrization. The first model core potentials that include the new formalism were developed for two 6p-block elements, Pb and Bi. The valence space of the 5p, 5d, 6s, and 6p orbitals was used because of the large SOC between the 5p and 6p orbitals. The model core potentials were validated in the calculations of atomic properties as well as spectroscopic constants of diatomic metal hydrides. The agreement between results of the model core potential and all-electron calculations was excellent, with energy errors of hundreds of cm(-1) and hundredths of eV, r(e) errors of thousandths of A, and omega(e) errors under 20 cm(-1). Two kinds of interplay between SOC effect and bonding process (antibonding and bonding SOC) were demonstrated using spin-free term potential curves of PbH and BiH. The present study is the first extension of the model core potential method beyond Breit-Pauli to Douglas-Kroll SOC calculations. PMID:19791854

  17. Half-quantized Non-Abelian Vortices in Neutron $^3P_2$ Superfluids inside Magnetars

    Masuda, Kota

    2016-01-01

    We point out that half-quantized non-Abelian vortices exist as the minimum energy states in rotating neutron $^3P_2$ superfluids in the inner cores of magnetars with magnetic field greater than $3 \\times 10^{15}$ Gauss, while they do not in ordinary neutron stars with smaller magnetic fields. One integer vortex is split into two half-quantized vortices. The number of vortices is about $10^{19}$ and they are separated at about $\\mu$m in a vortex lattice for typical parameters, while the vortex core size is about 10-100 fm. They are non-Abelian vortices characterized by non-Abelian first homotopy group, and consequently when two vortices corresponding to non-commutative elements collide, a rung vortex must be created between them, implying the formation of an entangled vortex network inside the cores of magnetars. We find the spontaneous magnetization in the vortex core showing anti-ferromagnetism whose typical magnitude is about $10^{8-9}$ Gauss that is ten times larger than that of integer vortices, when exte...

  18. Preservice Secondary Teachers Perceptions of College-Level Mathematics Content Connections with the Common Core State Standards for Mathematics

    Olson, Travis A.

    2016-01-01

    Preservice Secondary Mathematics Teachers (PSMTs) were surveyed to identify if they could connect early-secondary mathematics content (Grades 7-9) in the Common Core State Standards for Mathematics (CCSSM) with mathematics content studied in content courses for certification in secondary teacher preparation programs. Respondents were asked to…

  19. Expression of miR-199a-3p in human adipocytes is regulated by free fatty acids and adipokines.

    Gu, Nan; You, Lianghui; Shi, Chunmei; Yang, Lei; Pang, Lingxia; Cui, Xianwei; Ji, Chenbo; Zheng, Wen; Guo, Xirong

    2016-08-01

    Obesity is associated with a notable risk for disease, including risk of cardiovascular disorders, type 2 diabetes mellitus (T2DM) and hypertension. Adipose tissue modulates the metabolism by releasing free fatty acids (FFAs) and adipokines, including leptin, resistin, tumor necrosis factor-α (TNF-α) and interleukin 6 (IL‑6). Altered secretion patterns of FFAs and adipokines have been demonstrated to result in obesity‑associated insulin resistance (IR) and inflammatory responses. MicroRNA-199a-3p (miR)-199a-3p expression is significantly induced in differentiated human adipose-derived mesenchymal stem cells and indicates the association with T2DM. However, the association between miR-199a-3p levels in adipocytes and obesity‑associated IR, as well as inflammatory responses remains to be elucidated. The present study observed an elevation of miR‑199a‑3p expression level in mature human adipocytes (visceral) compared with pre-adipocytes. In addition, miR‑199a‑3p expression was higher in visceral adipose deposits from obese subjects. FFA, TNF-α, IL‑6 and leptin significantly induced miR‑199a‑3p expression in mature human adipocytes, while resistin had the opposite effect. miR‑199a‑3p may represent a factor in the modulation of obesity‑associated IR and inflammatory responses. PMID:27279151

  20. Research of Core Strength Training of Table Tennis at the Basic Level%基层乒乓球核心力量训练研究

    华卉

    2014-01-01

    乒乓球作为一项典型的隔网对抗性运动项目,特别是攻球和拉弧圈球时对基层运动员身体素质有着较高的要求,核心力量训练可提高核心部位的力量及各个核心肌群控制身体的稳定性。但由于基层乒乓球的开展会受到条件、经费、场地、器材等因素的限制,使核心力量训练无法良好完成,本文通过文献资料法、专家访谈法等研究方法,对基层乒乓球核心力量训练方法应用进行了分析研究,以期为基层乒乓球训练提供理论依据与支撑。%Table tennis as a typical netting confrontational sport, especially attacking driving and pull loop drive have higher requirements for grass-roots athletes' physical qualities. The core strength training can increase the power of the core part and the stability of the body controlled by the core muscles. But because the development of table tennis at the basic level will be affected by the limitation of conditions, funds, sites, equipment and other factors, the core strength training can't finish well. This paper analyzes and studies the core strength training method of table tennis at the grass-roots level by the means of literature consultation and expert interview method, so as to provide theoretical basis and support for table tennis training at the grass-roots level.

  1. MicroRNA-124-3p regulates cell proliferation, invasion, apoptosis, and bioenergetics by targeting PIM1 in astrocytoma.

    Deng, Danni; Wang, Lei; Chen, Yao; Li, Bowen; Xue, Lian; Shao, Naiyuan; Wang, Qiang; Xia, Xiwei; Yang, Yilin; Zhi, Feng

    2016-07-01

    The PIM1 protein is an important regulator of cell proliferation, the cell cycle, apoptosis, and metabolism in various human cancers. MicroRNAs (miRNAs) are powerful post-transcriptional gene regulators that function through translational repression or transcript destabilization. Therefore, we aimed to identify whether a close relationship exists between PIM1 and miRNAs. PIM1 protein levels and mRNA levels were significantly upregulated in astrocytoma tissues, indicating the oncogenic role of PIM1 in astrocytoma. Further bioinformatics analysis indicated that miR-124-3p targeted the 3'-UTR of PIM1. We also observed an inverse correlation between the miR-124-3p levels and PIM1 protein or mRNA levels in astrocytoma samples. Next, we experimentally confirmed that miR-124-3p directly recognizes the 3'-UTR of the PIM1 transcript and regulates PIM1 expression at both the protein and mRNA levels. Furthermore, we examined the biological consequences of miR-124-3p targeting PIM1 in vitro. We showed that the repression of PIM1 in astrocytoma cancer cells by miR-124-3p suppressed proliferation, invasion, and aerobic glycolysis and promoted apoptosis. We observed that the restoration or inhibition of PIM1 activity resulted in effects that were similar to those induced by miR-124-3p inhibitors or mimics in cancer cells. Finally, overexpression of PIM1 rescued the inhibitory effects of miR-124-3p. In summary, these findings aid in understanding the tumor-suppressive role of miR-124-3p in astrocytoma pathogenesis through the inhibition of PIM1 translation. PMID:27088547

  2. Relativistic transition probabilities and lifetimes of low-lying levels in ytterbium

    Multiconfiguration Dirac-Fock calculations of E1, E2, M1 and M2 transition probabilities and lifetimes for the low-lying levels of neutral ytterbium are reported. For E1 transitions the valence-core electron correlations are also included in the core-polarization model. In particular, the lifetimes of the 6s6p 1P1 and 3P1 states, when corrected for core polarization, are found to be 4.78 ns and 1294 ns, respectively. The lifetime of the metastable 6s6p 3P2 state is calculated to be 14.5 s. (author)

  3. JS3P: junior staff programme pilot project

    Pretrel, H.; Tregoures, N.; Bessiron, V.; Dehoyos, A.; Delvallee, I.; Brisson, N.; Debayle, C.; Dubreuil, M.; Nicaise, G.; Perignon, J.P.; Richard, J. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 13 - Saint-Paul-lez-Durance (France); Reinke, N.; Kaulard, J.; Burgener, M.; Keesmann, S.; Schramm, B.; Seubert, A.; Sternkopf, J.; Thuma, G.; Weber, S. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koln (Germany); Smidts, O.; Maillet, E.; Bucalossi, A.; Van haesendonck, M.; Uyttenhove, W.; Mertens, J. [AVN, Bruxelles (Belgium)

    2006-07-01

    Concept: The objective of the project is to allow junior staff members from the European Technical Safety Organisations (TSOs), IRSN, GRS and AVN, to work together with the final goal of creating a junior staff network, based on technical, cultural and personal interests. These projects are to show junior staff members at a very early stage during their career the need for European collaborations. They are also a tool to explore new subjects of co-operation. It is an initiative that should strengthen the links between the organisations and contribute to establishing the future of nuclear safety in Europe. A JS3P (Junior Staff Programme Pilot Project) is a project done jointly by 'junior' staff members from the three TSOs, where experience of 'seniors' is also integrated when needed. Compared to other collaborative activities, it has certain specific features. The JS3P favours staff exchanges, and technical meetings of several days should be planned during a project in order to encourage people to work together. Technical objectives are shared and the work is done jointly (reports, articles). The team involved in the JS3P should be as small as possible to favour its efficiency. The JS3P is short and easy to realize. Its duration is fixed to a maximum of about 12 months with the option to be prolonged. Typical topics are bibliographic work, comparison issues, scientific surveys, benchmark exercises and prospective investigations on innovative ideas. They can be linked to existing joint projects and then form a smaller module integrated into the large project. Topics may concern prospective issues, tentatively investigating new topics that can be seen as exploratory co-operation projects. Subjects may also concern research issues that are not a priority but that deserve to be investigated as new attractive topics. The JS3P is defined and managed by junior staff members. It is approved by a management board committee and supervised by a technical

  4. JS3P: junior staff programme pilot project

    Concept: The objective of the project is to allow junior staff members from the European Technical Safety Organisations (TSOs), IRSN, GRS and AVN, to work together with the final goal of creating a junior staff network, based on technical, cultural and personal interests. These projects are to show junior staff members at a very early stage during their career the need for European collaborations. They are also a tool to explore new subjects of co-operation. It is an initiative that should strengthen the links between the organisations and contribute to establishing the future of nuclear safety in Europe. A JS3P (Junior Staff Programme Pilot Project) is a project done jointly by 'junior' staff members from the three TSOs, where experience of 'seniors' is also integrated when needed. Compared to other collaborative activities, it has certain specific features. The JS3P favours staff exchanges, and technical meetings of several days should be planned during a project in order to encourage people to work together. Technical objectives are shared and the work is done jointly (reports, articles). The team involved in the JS3P should be as small as possible to favour its efficiency. The JS3P is short and easy to realize. Its duration is fixed to a maximum of about 12 months with the option to be prolonged. Typical topics are bibliographic work, comparison issues, scientific surveys, benchmark exercises and prospective investigations on innovative ideas. They can be linked to existing joint projects and then form a smaller module integrated into the large project. Topics may concern prospective issues, tentatively investigating new topics that can be seen as exploratory co-operation projects. Subjects may also concern research issues that are not a priority but that deserve to be investigated as new attractive topics. The JS3P is defined and managed by junior staff members. It is approved by a management board committee and supervised by a technical steering committee

  5. Evidence for replicate 5p core levels in photoelectron spectra of Eu metal due to nonconstant kinetic-energy resonant Auger decay

    Satellites on the low-binding-energy side of core-level photoelectron emission due to extra 4f screening are a well-known feature in the x-ray photoelectron spectra of valence fluctuation materials and rare-earth metals. A notable exception is Eu metal, where up to now no low-binding-energy satellite has been observed. In this paper we show that in Eu metal the 4d-4f resonance can decay via a resonant Auger decay, which is not a constant kinetic-energy feature due to a rapid change of the strength of 4f screening with excitation energy, establishing a low-binding-energy replica of the 5p core-level photoelectron emission. (c) 1999 The American Physical Society

  6. Surface Carrier Dynamics on Semiconductor Studied with Femtosecond Core-Level Photoelectron Spectroscopy Using Extreme Ultraviolet High-Order Harmonic Source

    Sogawa T.

    2013-03-01

    Full Text Available We have used a femtosecond time-resolved core-level surface PES system based on the 92-eV harmonic source to study the surface carrier dynamics that induces the transient SPV on semiconductor surfaces. We clarified the temporal evolution of the transient SPV characterized by the time of the photo-generated carrier separation and recombination. This result demonstrates the potential of this technique for clarifying the initial stage of the surface carrier dynamics after photoexcitation.

  7. Surface Carrier Dynamics on Semiconductor Studied with Femtosecond Core-Level Photoelectron Spectroscopy Using Extreme Ultraviolet High-Order Harmonic Source

    Oguri, K.; Tsunoi, T.; Kato, K.; Nakano, H.; Nishikawa, T.; Gotoh, H.; Tateno, K.; Sogawa, T.

    2013-03-01

    We have used a femtosecond time-resolved core-level surface PES system based on the 92-eV harmonic source to study the surface carrier dynamics that induces the transient SPV on semiconductor surfaces. We clarified the temporal evolution of the transient SPV characterized by the time of the photo-generated carrier separation and recombination. This result demonstrates the potential of this technique for clarifying the initial stage of the surface carrier dynamics after photoexcitation.

  8. Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe2

    Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe2, one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies

  9. Thermodynamics, core-level spectroscopy, morphology, and work function study of different TiCl3 crystalline phases: A theoretical approach

    Highlights: • Three TiCl3 polymorphs materials were systematically investigated. • Structural results agree well with experimental and available theoretical data. • Morphological and thermodynamic properties were computed and analyzed. • Core-level spectroscopy and work function were obtained. - Abstract: Computer simulation has been widely applied in many research fields owing to its superiority in revealing an insight understanding of the phenomena. In this work, the thermodynamics, core-level spectroscopy, morphology, and work function of TiCl3 with three different crystalline phases (α, β, and γ) have been comprehensively computed employing the Materials Studio package. Our computational DFT-D approach gives a structural description of the TiCl3 phases in good agreement with experiment. The core-level spectroscopy confirmed that α, β, and γ modifications for TiCl3 have lightly affected on the valences of the constitutional elements. A series of possible growth faces (h k l) were deduced using the classic Bravais–Friedel–Donnay–Harker (BFDH) model. We conclude that the sequence of work function for (0 0 1) surface was α > β ≈ γ

  10. Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe{sub 2}

    Nelson, A.J. [Colorado School of Mines, Golden, CO (United States); Berry, G.; Rockett, A. [Univ. of Illinois, Urbana-Champaign, IL (United States)] [and others

    1997-04-01

    Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe{sub 2}, one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies.

  11. Thermodynamics, core-level spectroscopy, morphology, and work function study of different TiCl{sub 3} crystalline phases: A theoretical approach

    Guo, Lei [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Li, Wenpo, E-mail: cqliwp@163.com [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Feng, Wenjiang [College of Physics Science and Technology, Shenyang Normal University, Shenyang 110034 (China); Zhang, Zhipeng [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Zhang, Shengtao [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China)

    2014-07-25

    Highlights: • Three TiCl{sub 3} polymorphs materials were systematically investigated. • Structural results agree well with experimental and available theoretical data. • Morphological and thermodynamic properties were computed and analyzed. • Core-level spectroscopy and work function were obtained. - Abstract: Computer simulation has been widely applied in many research fields owing to its superiority in revealing an insight understanding of the phenomena. In this work, the thermodynamics, core-level spectroscopy, morphology, and work function of TiCl{sub 3} with three different crystalline phases (α, β, and γ) have been comprehensively computed employing the Materials Studio package. Our computational DFT-D approach gives a structural description of the TiCl{sub 3} phases in good agreement with experiment. The core-level spectroscopy confirmed that α, β, and γ modifications for TiCl{sub 3} have lightly affected on the valences of the constitutional elements. A series of possible growth faces (h k l) were deduced using the classic Bravais–Friedel–Donnay–Harker (BFDH) model. We conclude that the sequence of work function for (0 0 1) surface was α > β ≈ γ.

  12. Products of the Benzene + O(3P) Reaction

    Taatjes, Craig A.; Osborn, David L.; Selby, Talitha M.; Meloni, Giovanni; Trevitt, Adam J.; Epifanovsky, Evgeny; Krylov, Anna I.; Sirjean, Baptiste; Dames, Enoch; Wang, Hai

    2009-12-21

    The gas-phase reaction of benzene with O(3P) is of considerable interest for modeling of aromatic oxidation, and also because there exist fundamental questions concerning the prominence of intersystem crossing in the reaction. While its overall rate constant has been studied extensively, there are still significant uncertainties in the product distribution. The reaction proceeds mainly through the addition of the O atom to benzene, forming an initial triplet diradical adduct, which can either dissociate to form the phenoxy radical and H atom, or undergo intersystem crossing onto a singlet surface, followed by a multiplicity of internal isomerizations, leading to several possible reaction products. In this work, we examined the product branching ratios of the reaction between benzene and O(3P) over the temperature range of 300 to 1000 K and pressure range of 1 to 10 Torr. The reactions were initiated by pulsed-laser photolysis of NO2 in the presence of benzene and helium buffer in a slow-flow reactor, and reaction products were identified by using the multiplexed chemical kinetics photoionization mass spectrometer operating at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Phenol and phenoxy radical were detected and quantified. Cyclopentadiene and cyclopentadienyl radical were directly identified for the first time. Finally, ab initio calculations and master equation/RRKM modeling were used to reproduce the experimental branching ratios, yielding pressure-dependent rate expressions for the reaction channels, including phenoxy + H, phenol, cyclopentadiene + CO, which are proposed for kinetic modeling of benzene oxidation.

  13. Photoinduced Kondo effect in CeZn3P3

    Kitagawa, J.; Kitajima, D.; Shimokawa, K.; Takaki, H.

    2016-01-01

    The Kondo effect, which originates from the screening of a localized magnetic moment by a spin-spin interaction, is widely observed in nonartificial magnetic materials, artificial quantum dots, and carbon nanotubes. In devices based on quantum dots or carbon nanotubes that target quantum information applications, the Kondo effect can be tuned by a gate voltage, a magnetic field, or light. However, the manipulation of the Kondo effect in nonartificial materials has not been thoroughly studied; in particular, the artificial creation of the Kondo effect remains unexplored. Per this subject study, however, a route for the optical creation of the Kondo effect in the nonartificial material p -type semiconductor CeZn3P3 is presented. The Kondo effect emerges under visible-light illumination of the material by a continuous-wave laser diode and is ultimately revealed by photoinduced electrical resistivity, which clearly exhibits a logarithmic temperature dependency. By contrast, a La-based compound (LaZn3P3 ) displays only normal metallic behavior under similar illumination. The photoinduced Kondo effect, which occurs at higher temperatures when compared with the Kondo effect in artificial systems, provides a potential range of operation for not only quantum information/computation devices but also for operation of magneto-optic devices, thereby expanding the range of device applications based on the Kondo effect.

  14. Colloidal CdSe/Cu3P/CdSe nanocrystal heterostructures and their evolution upon thermal annealing.

    De Trizio, Luca; De Donato, Francesco; Casu, Alberto; Genovese, Alessandro; Falqui, Andrea; Povia, Mauro; Manna, Liberato

    2013-05-28

    We report the synthesis of colloidal CdSe/Cu(3)P/CdSe nanocrystal heterostructures grown from hexagonal Cu(3)P platelets as templates. One type of heterostructure was a sort of "coral", formed by vertical pillars of CdSe grown preferentially on both basal facets of a Cu(3)P platelet and at its edges. Another type of heterostructure had a "sandwich" type of architecture, formed by two thick, epitaxial CdSe layers encasing the original Cu(3)P platelet. When the sandwiches were annealed under vacuum up to 450 °C, sublimation of P and Cd species with concomitant interdiffusion of Cu and Se species was observed by in situ HR- and EFTEM analyses. These processes transformed the starting sandwiches into Cu2Se nanoplatelets. Under the same conditions, both the pristine (uncoated) Cu(3)P platelets and a control sample made of isolated CdSe nanocrystals were stable. Therefore, the thermal instability of the sandwiches under vacuum might be explained by the diffusion of Cu species from Cu(3)P cores into CdSe domains, which triggered sublimation of Cd, as well as out-diffusion of P species and their partial sublimation, together with the overall transformation of the sandwiches into Cu(2)Se nanocrystals. A similar fate was followed by the coral-like structures. These CdSe/Cu(3)P/CdSe nanocrystals are therefore an example of a nanostructure that is thermally unstable, despite its separate components showing to be stable under the same conditions. PMID:23557168

  15. Theory for resonant X-ray emission of core excitons with lattice relaxation: changeover from shallow to deep level

    A simple model is proposed for the X-ray emission of core excitons which is accompanied by a strong lattice relaxation. The effect of electron itinerancy in the conduction band is taken into account in addition to that of a local attractive potential and the lattice deformation. The X-ray absorption and the emission spectra are calculated exactly. It is shown that, as the lattice deformation goes on, the wave function of the exciton shrinks and the effective electron-phonon interaction changes from the weak coupling regime to the strong coupling regime

  16. Effects on intercombination transition rates and branching ratios-the UV0.01 (3s23p23P1,2 - 3s3p35S2) multiplet in Si I-like ions revisited

    We report on large-scale ab initio calculations for intercombination lines in Si I-like ions. Two measurable quantities, the lifetime of the 3s3p35S2 level and the branching ratio of the two lines are discussed, to infer the importance of different features of our calculations. The effects of core polarization, two-body spin-dependent operators and Dirac contra Breit-Pauli approaches are discussed. Earlier calculations are reviewed and evaluated. The calculated lifetimes are in good agreement with experiments, while a discrepancy persists for branching ratios

  17. miR-208-3p promotes hepatocellular carcinoma cell proliferation and invasion through regulating ARID2 expression

    MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at post-transcriptional level. miRNA dysregulation plays a causal role in cancer progression. In this study, miR-208-3p was highly expressed and directly repressed ARID2 expression. As a result, ARID2 expression in hepatocellular carcinoma (HCC) was decreased. In vitro, miR-208-3p down-regulation and ARID2 over-expression elicited similar inhibitory effects on HCC cell proliferation and invasion. In vivo test results revealed that miR-208-3p down-regulation inhibited HCC tumorigenesis in Hep3B cells. Moreover, ARID2 was possibly a downstream element of transforming growth factor beta1 (TGFβ1)/miR-208-3p/ARID2 regulatory pathway. These findings suggested that miR-208-3p up-regulation is associated with HCC cell progression and may provide a new target for liver cancer treatment. - Highlights: • miR-208-3p was highly expressed and directly repressed the expression of ARID2 in HCC. • miR-208-3p contributed to HCC cell progression both in vitro and in vivo. • Over-expression of ARID2 inhibited the HCC cell proliferation and invasion. • Restoration of ARID2 partly reversed the the effect of miR-208-3p down-regulation on HCC cells. • Newly regulatory pathway: miR-208-3p mediated the repression of ARID2 by TGFβ1 in HCC cells

  18. MicroRNA-23a-3p promotes the development of osteoarthritis by directly targeting SMAD3 in chondrocytes.

    Kang, Liang; Yang, Cao; Song, Yu; Liu, Wei; Wang, Kun; Li, Shuai; Zhang, Yukun

    2016-09-01

    Osteoarthritis (OA) is a common chronic degenerative joint disease. Progressive destruction of the integrity of articular cartilage is an important pathological feature, but treatment options that reverse this damage have not been developed. According to recent studies, microRNAs have important regulatory roles in the initiation and progression of OA. In the current study, the biological effects of miR-23a-3p and its expression in OA tissues were examined. We found that miR-23a-3p expression was obviously higher and SMAD3 expression was significantly lower in OA cartilage than in normal tissues. The hypomethylation status of CpG islands in the promoter region of miR-23a-3p was confirmed by methylation-specific polymerase chain reaction in OA cartilage tissues. Furthermore, a bioinformatics analysis and luciferase reporter assay identified SMAD3 as a target gene of miR-23a-3p and SMAD3 expression at both the protein and mRNA levels was inhibited by miR-23a-3p. A functional analysis demonstrated that miR-23a-3p overexpression suppresses type II collagen and aggrecan expression, while miR-23a-3p inhibition had the opposite effects. Small interfering RNA-mediated knockdown of SMAD3 reversed the effects of the miR-23a-3p inhibitor on the expression of type II collagen and aggrecan. Our results suggested that miR-23a-3p contributes to OA progression by directly targeting SMAD3, providing a potential therapeutic target for OA treatment. PMID:27318087

  19. miR-208-3p promotes hepatocellular carcinoma cell proliferation and invasion through regulating ARID2 expression

    Yu, Peng; Wu, Dingguo; You, Yu; Sun, Jing; Lu, Lele; Tan, Jiaxing; Bie, Ping, E-mail: bieping2010@163.com

    2015-08-15

    MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at post-transcriptional level. miRNA dysregulation plays a causal role in cancer progression. In this study, miR-208-3p was highly expressed and directly repressed ARID2 expression. As a result, ARID2 expression in hepatocellular carcinoma (HCC) was decreased. In vitro, miR-208-3p down-regulation and ARID2 over-expression elicited similar inhibitory effects on HCC cell proliferation and invasion. In vivo test results revealed that miR-208-3p down-regulation inhibited HCC tumorigenesis in Hep3B cells. Moreover, ARID2 was possibly a downstream element of transforming growth factor beta1 (TGFβ1)/miR-208-3p/ARID2 regulatory pathway. These findings suggested that miR-208-3p up-regulation is associated with HCC cell progression and may provide a new target for liver cancer treatment. - Highlights: • miR-208-3p was highly expressed and directly repressed the expression of ARID2 in HCC. • miR-208-3p contributed to HCC cell progression both in vitro and in vivo. • Over-expression of ARID2 inhibited the HCC cell proliferation and invasion. • Restoration of ARID2 partly reversed the the effect of miR-208-3p down-regulation on HCC cells. • Newly regulatory pathway: miR-208-3p mediated the repression of ARID2 by TGFβ1 in HCC cells.

  20. Clay-mineral assemblages from some levels of K-118 drill core of Maha Sarakham evaporites, northeastern Thailand

    Suwanich, Parkorn

    Clay-mineral assemblages in Middle Clastic, Middle Salt, Lower Clastic, Potash Zone, and Lower Salt, totalling 13 samples from K-118 drill core, in the Maha Sarakham Formation, Khorat Basin, northeastern Thailand were studied. The clay-size particles were separated from the water-soluble salt by water leaching. Then the samples were leached again in the EDTA solution and separated into clay-size particles by using the timing sedimentation. The EDTA-clay residues were divided and analyzed by using the XRD and XRF method. The XRD peaks show that the major-clay minerals are chlorite, illite, and mixed-layer corrensite including traces of rectorite? and paragonite? The other clay-size particles are quartz and potassium feldspar. The XRF results indicate Mg-rich values and moderate MgAl atom ratio values in those clay minerals. The variable Fe, Na, and K contents in the clay-mineral assemblages can explain the environment of deposition compared to the positions of the samples from the core. Hypothetically, mineralogy and the chemistry of the residual assemblages strongly indicate that severe alteration and Mg-enrichment of normal clay detritus occurred in the evaporite environment through brine-sediment interaction. The various Mg-enrichment varies along the various members reflecting whether sedimentation is near or far from the hypersaline brine.

  1. First Detection of [C I] $^3$P$_1$-$^3$P$_0$ Emission from a Protoplanetary Disk

    Tsukagoshi, Takashi; Saito, Masao; Kitamura, Yoshimi; Shimajiri, Yoshito; Kawabe, Ryohei

    2015-01-01

    We performed single point [C I] $^3$P$_1$-$^3$P$_0$ and CO J=4-3 observations toward three T Tauri stars, DM Tau, LkCa 15, and TW Hya, using the Atacama Large Millimeter/submillimeter Array (ALMA) Band 8 qualification model receiver installed on the Atacama Submillimeter Telescope Experiment (ASTE). Two protostars in the Taurus L1551 region, L1551 IRS 5 and HL Tau, were also observed. We successfully detected [C I] emission from the protoplanetary disk around DM Tau as well as the protostellar targets. The spectral profile of the [C I] emission from the protoplanetary disk is marginally single-peaked, suggesting that atomic carbon (C) extends toward the outermost disk. The detected [C I] emission is optically thin and the column densities of C are estimated to be <~10$^{16}$ cm$^{-2}$ and ~10$^{17}$ cm$^{-2}$ for the T Tauri star targets and the protostars, respectively. We found a clear difference in the total mass ratio of C to dust, $M$(C)/$M$(dust), between the T Tauri stars and protostellar targets; t...

  2. Novel Mad2-targeting miR-493-3p controls mitotic fidelity and cancer cells' sensitivity to paclitaxel.

    Tambe, Mahesh; Pruikkonen, Sofia; Mäki-Jouppila, Jenni; Chen, Ping; Elgaaen, Bente Vilming; Straume, Anne Hege; Huhtinen, Kaisa; Cárpen, Olli; Lønning, Per Eystein; Davidson, Ben; Hautaniemi, Sampsa; Kallio, Marko J

    2016-03-15

    The molecular pathways that contribute to the proliferation and drug response of cancer cells are highly complex and currently insufficiently characterized. We have identified a previously unknown microRNA-based mechanism that provides cancer cells means to stimulate tumorigenesis via increased genomic instability and, at the same time, evade the action of clinically utilized microtubule drugs. We demonstrate miR-493-3p to be a novel negative regulator of mitotic arrest deficient-2 (MAD2), an essential component of the spindle assembly checkpoint that monitors the fidelity of chromosome segregation. The microRNA targets the 3' UTR of Mad2 mRNA thereby preventing translation of the Mad2 protein. In cancer cells, overexpression of miR-493-3p induced a premature mitotic exit that led to increased frequency of aneuploidy and cellular senescence in the progeny cells. Importantly, excess of the miR-493-3p conferred resistance of cancer cells to microtubule drugs. In human neoplasms, miR-493-3p and Mad2 expression alterations correlated with advanced ovarian cancer forms and high miR-493-3p levels were associated with reduced survival of ovarian and breast cancer patients with aggressive tumors, especially in the paclitaxel therapy arm. Our results suggest that intratumoral profiling of miR-493-3p and Mad2 levels can have diagnostic value in predicting the efficacy of taxane chemotherapy. PMID:26943585

  3. Integrated multi-omics analyses reveal the pleiotropic nature of the control of gene expression by Puf3p.

    Kershaw, Christopher J; Costello, Joseph L; Talavera, David; Rowe, William; Castelli, Lydia M; Sims, Paul F G; Grant, Christopher M; Ashe, Mark P; Hubbard, Simon J; Pavitt, Graham D

    2015-01-01

    The PUF family of RNA-binding proteins regulate gene expression post-transcriptionally. Saccharomyces cerevisiae Puf3p is characterised as binding nuclear-encoded mRNAs specifying mitochondrial proteins. Extensive studies of its regulation of COX17 demonstrate its role in mRNA decay. Using integrated genome-wide approaches we define an expanded set of Puf3p target mRNAs and quantitatively assessed the global impact of loss of PUF3 on gene expression using mRNA and polysome profiling and quantitative proteomics. In agreement with prior studies, our sequencing of affinity-purified Puf3-TAP associated mRNAs (RIP-seq) identified mRNAs encoding mitochondrially-targeted proteins. Additionally, we also found 720 new mRNA targets that predominantly encode proteins that enter the nucleus. Comparing transcript levels in wild-type and puf3∆ cells revealed that only a small fraction of mRNA levels alter, suggesting Puf3p determines mRNA stability for only a limited subset of its target mRNAs. Finally, proteomic and translatomic studies suggest that loss of Puf3p has widespread, but modest, impact on mRNA translation. Taken together our integrated multi-omics data point to multiple classes of Puf3p targets, which display coherent post-transcriptional regulatory properties and suggest Puf3p plays a broad, but nuanced, role in the fine-tuning of gene expression. PMID:26493364

  4. Transition probabilities for the 3s2 3p(2P0)-3s3p2(4P) intersystem lines of Si II

    Calamai, Anthony G.; Smith, Peter L.; Bergeson, S. D.

    1993-01-01

    Intensity ratios of lines of the spin-changing 'intersystem' multiplet of S II (4P yields 2P0) at 234 nm have been used to determine electron densities and temperatures in a variety of astrophysical environments. However, the accuracy of these diagnostic calculations have been limited by uncertainties associated with the available atomic data. We report the first laboratory measurement, using an ion-trapping technique, of the radiative lifetimes of the three metastable levels of the 3s3p2 4P term of Si II. Our results are 104 +/- 16, 406 +/- 33, and 811 +/- 77 micro-s for lifetimes of the J = 1/2, 5/2, and 3/2 levels, respectively. A-values were derived from our lifetimes by use of measured branching fractions. Our A-values, which differ from calculated values by 30 percent or more, should give better agreement between modeled and observed Si II line ratios.

  5. Optical potentials for Ne*(3P2,0)-Ar, N2 interactions

    Baudon, J.; Feron, P.; Miniatura, C.; Perales, F.; Reinhardt, J.; Robert, J.; Haberland, H.; Brunetti, B.; Vecchiocattivi, F.

    1991-08-01

    The differential elastic cross sections for Ne*(3P2,0)-Ar and Ne*(3P2,0)-N2 collisions have been measured in crossed beam experiments at 0.064 and 0.318 and at 0.071 and 0.295 eV, collision energies, respectively. These results have been analyzed simultaneously with integral cross sections and total ionization cross sections already available and optical spherical potentials for these two systems have been obtained. These potentials appear to be rather accurate in the distance range from 2.5 to ˜9 and from 3.0 to ˜9 Å for Ne*-Ar and Ne*-N2, respectively. The well depths and equilibrium distances are 5.12 meV and 4.9 Å for Ne*-Ar and 3.56 meV and 5.40 Å for Ne*-N2. The short-range repulsion in both cases exhibits a change in slope which can be correlated with the influence, for the interaction at shorter distances, of the Ne+ core of the metastable atom, which becomes less effective when the intermolecular distance increases. The optical potentials proposed here are given in analytical form suitable for the calculation of dynamical observables of these systems.

  6. O 1s core levels in Bi2Sr2CaCu2O8+δ single crystals

    High-quality Bi2Sr2CaCu2O8+δ superconducting single crystals, annealed at different oxygen partial pressures, have been studied using angular-resolved x-ray photoelectron spectroscopy with a resolution higher than that used in any previous study. Two states of the oxygen, separated by ∼0.7 eV, are unambiguously observed. Examining these components at different angles makes it possible to distinguish bulk from surface components. Using this capability we discover that annealing under lower oxygen partial pressure (1 atm) results in oxygen intercalation beneath the Bi-O surface layer of the crystal, whereas for higher-pressure anneals (12 atm) additional oxygen is found on the Bi-O surfaces. This steplike intercalation mechanism is also confirmed by the changes observed in the Cu and Bi core lines as a function of the annealing oxygen partial pressure

  7. Relativistic effects on the hyperfine structures of 2p4(3P)3p 2Do, 4Do and 4Po in 19F I

    Carette, Thomas; Li, Jiguang; Godefroid, Michel

    2013-01-01

    The hyperfine interaction constants of the 2p4(3P)3p 2Do_{3/2,5/2}, 4Do_{1/2-7/2} and 4Po_{1/2-5/2} levels in neutral fluorine are investigated theoretically. Large-scale calculations are carried out using the multiconfiguration Hartree-Fock (MCHF) and Dirac-Hartree-Fock (MCDHF) methods. In the framework of the MCHF approach, the relativistic effects are taken into account in the Breit-Pauli approximation using non relativistic orbitals. In the fully relativistic approach, the orbitals are optimized using the Dirac-Coulomb Hamiltonian with correlation models inspired by the non relativistic calculations. Higher-order excitations are captured through multireference configuration interaction calculations including the Breit interaction. In a third (intermediate) approach, the Dirac-Coulomb-Breit Hamiltonian matrix is diagonalized in a relativistic configuration space built with non relativistic MCHF radial functions converted into Dirac spinors using the Pauli approximation. The magnetic dipole hyperfine struct...

  8. Absolute frequency measurement of the magnesium intercombination transition $^1S_0 \\to ^3P_1$

    Friebe, Jan; Riedmann, Matthias; Moldenhauer, Karsten; Mehlstäubler, Tanja; Rehbein, Nils; Lisdat, Christian; Rasel, Ernst M; Ertmer, Wolfgang; Schnatz, Harald; Lipphardt, Burghard; Grosche, Gesine

    2007-01-01

    We report on a frequency measurement of the $(3s^2)^1S_0\\to(3s3p)^3P_1$ clock transition of $^{24}$Mg on a thermal atomic beam. The intercombination transition has been referenced to a portable primary Cs frequency standard with the help of a femtosecond fiber laser frequency comb. The achieved uncertainty is $2.5\\times10^{-12}$ which corresponds to an increase in accuracy of six orders of magnitude compared to previous results. The measured frequency value permits the calculation of several other optical transitions from $^1S_0$ to the $^3P_J$-level system for $^{24}$Mg, $^{25}$Mg and $^{26}$Mg. We describe in detail the components of our optical frequency standard like the stabilized spectroscopy laser, the atomic beam apparatus used for Ramsey-Bord\\'e interferometry and the frequency comb generator and discuss the uncertainty contributions to our measurement including the first and second order Doppler effect. An upper limit of $3\\times10^{-13}$ in one second for the short term instability of our optical f...

  9. Ypq3p-dependent histidine uptake by the vacuolar membrane vesicles of Saccharomyces cerevisiae.

    Manabe, Kunio; Kawano-Kawada, Miyuki; Ikeda, Koichi; Sekito, Takayuki; Kakinuma, Yoshimi

    2016-06-01

    The vacuolar membrane proteins Ypq1p, Ypq2p, and Ypq3p of Saccharomyces cerevisiae are known as the members of the PQ-loop protein family. We found that the ATP-dependent uptake activities of arginine and histidine by the vacuolar membrane vesicles were decreased by ypq2Δ and ypq3Δ mutations, respectively. YPQ1 and AVT1, which are involved in the vacuolar uptake of lysine/arginine and histidine, respectively, were deleted in addition to ypq2Δ and ypq3Δ. The vacuolar membrane vesicles isolated from the resulting quadruple deletion mutant ypq1Δypq2Δypq3Δavt1Δ completely lost the uptake activity of basic amino acids, and that of histidine, but not lysine and arginine, was evidently enhanced by overexpressing YPQ3 in the mutant. These results suggest that Ypq3p is specifically involved in the vacuolar uptake of histidine in S. cerevisiae. The cellular level of Ypq3p-HA(3) was enhanced by depletion of histidine from culture medium, suggesting that it is regulated by the substrate. PMID:26928127

  10. Self-consistent Green’s-function technique for bulk and surface impurity calculations: Surface core-level shifts by complete screening

    Aldén, M.; Abrikosov, I. A.; Johansson, B.;

    1994-01-01

    We have implemented an efficient self-consistent Green's-function technique, based on the tight-binding linear-muffin-tin-orbitals method, for calculating the electronic structure and total energy of a substitutional impurity located either in the bulk or at the surface. The technique makes use of...... shift obtained from a polycrystalline surface. Comparison is made with independent theoretical data for the surface core-level eigenvalue shift, and the much debated role of the so-called initial-and final-state contributions to the SCLS is discussed....

  11. Ionic fragmentation following core-level photoionization of Sn(CH3)4 by soft X-rays

    Ionic fragmentation following the photoionization of Sn(CH3)4 (TMT) has been studied in the photon energy range of 60-600 eV using synchrotron radiation and time-of-flight mass spectrometry. Each of the Sn:4d, 4p, 3d and C:1s photoionization leads to a type of ionic fragmentation that is characteristic of each ionized core. The Sn:4d photoionization above 60 eV predominantly produces the doubly-charged TMT which dissociates into two singly-charged ions and some neutral fragments. The ions produced in this pathway are CH3+, C2H3+, C2H5+, SnCHm+ and/or Sn+. The Sn:4p photoionization produces the triply-charged TMT and enhances the production of H+, CHsub(m'+) (m' = 0-3) and Sn+ significantly. The Sn:3d photoionization produces multiply-charged TMT whose charges are 3-5 and enhances the production of H+, CHsub(m'+) (m' = 0-2) and Sn+ significantly. The C:1s photoionization produces doubly-charged TMT via the KVV Auger transition and enhances the production of CH3+, C2H3+, SnCHm+ and/or Sn+. (orig.)

  12. miR-193a-3p regulation of chemoradiation resistance in oesophageal cancer cells via the PSEN1 gene.

    Meng, Fang; Qian, Liting; Lv, Lei; Ding, Bojin; Zhou, Gieping; Cheng, Xu; Niu, Sanqiang; Liang, Yu

    2016-04-01

    Chemoradiation therapy is an important component of the curative treatment for oesophageal carcinomas. These therapeutic effects are prevented in patients according to radioresistance and multi-drug resistance, and the cause of such resistance remains unclear. In this study, we identified the role of miR-193a-3p in modulating the radioresistance and chemoresistance of oesophageal cancer cells. We found that KYSE150 and KYSE410 cells could be characterized as relatively radiation-sensitive and radiation-resistant cells, respectively. Similarly, KYSE150 and KYSE410 cells were found to be chemosensitive and chemoresistant, respectively. Over-expression of miR-193a-3p increased the radioresistance and chemoresistance of oesophageal squamous cell carcinoma (ESCC) cells. In contrast, the down-regulation of miR-193a-3p decreased the radioresistance and chemoresistance of ESCC cells. In addition, miR-193a-3p inducing DNA damage has also been demonstrated through measuring the level of gamma-H2AX associated with miR-193a-3p. Moreover, a small interfering RNA(siRNA)-induced repression of the PSEN1 gene had an effect similar to that of miR-193a-3p up-regulation. The above processes also inhibited oesophageal cancer cells apoptosis. These findings suggest that miR-193a-3p contributes to the radiation and chemotherapy resistance of oesophageal carcinoma by down-regulating PSEN1. Thus, miR-193a-3p and PSEN1 might be potential biomarkers for chemoradiation resistant cancers. PMID:26743123

  13. Li induced effects in the core level and π-band electronic structure of graphene grown on C-face SiC

    Johansson, Leif I., E-mail: lij@ifm.liu.se; Xia, Chao; Virojanadara, Chariya [Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping (Sweden)

    2015-11-15

    Studies of the effects induced in the electronic structure after Li deposition, and subsequent heating, on graphene samples prepared on C-face SiC are reported. The as prepared graphene samples are essentially undoped, but after Li deposition, the Dirac point shifts down to 1.2 eV below the Fermi level due to electron doping. The shape of the C 1s level also indicates a doping concentration of around 10{sup 14 }cm{sup −2} after Li deposition, when compared with recent calculated results of core level spectra of graphene. The C 1s, Si 2p, and Li 1s core level results show little intercalation directly after deposition but that most of the Li has intercalated after heating at 280 °C. Heating at higher temperatures leads to desorption of Li from the sample, and at 1030 °C, Li can no longer be detected on the sample. The single π-band observable from multilayer C-face graphene samples in conventional angle resolved photoelectron spectroscopy is reasonably sharp both on the initially prepared sample and after Li deposition. After heating at 280 °C, the π-band appears more diffuse and possibly split. The Dirac point becomes located at 0.4 eV below the Fermi level, which indicates occurrence of a significant reduction in the electron doping concentration. Constant energy photoelectron distribution patterns extracted from the as prepared graphene C-face sample and also after Li deposition and heating at 280 °C look very similar to earlier calculated distribution patterns for monolayer graphene.

  14. Li induced effects in the core level and π-band electronic structure of graphene grown on C-face SiC

    Studies of the effects induced in the electronic structure after Li deposition, and subsequent heating, on graphene samples prepared on C-face SiC are reported. The as prepared graphene samples are essentially undoped, but after Li deposition, the Dirac point shifts down to 1.2 eV below the Fermi level due to electron doping. The shape of the C 1s level also indicates a doping concentration of around 1014 cm−2 after Li deposition, when compared with recent calculated results of core level spectra of graphene. The C 1s, Si 2p, and Li 1s core level results show little intercalation directly after deposition but that most of the Li has intercalated after heating at 280 °C. Heating at higher temperatures leads to desorption of Li from the sample, and at 1030 °C, Li can no longer be detected on the sample. The single π-band observable from multilayer C-face graphene samples in conventional angle resolved photoelectron spectroscopy is reasonably sharp both on the initially prepared sample and after Li deposition. After heating at 280 °C, the π-band appears more diffuse and possibly split. The Dirac point becomes located at 0.4 eV below the Fermi level, which indicates occurrence of a significant reduction in the electron doping concentration. Constant energy photoelectron distribution patterns extracted from the as prepared graphene C-face sample and also after Li deposition and heating at 280 °C look very similar to earlier calculated distribution patterns for monolayer graphene

  15. Stratigraphic analysis of lake level fluctuations in Lake Ohrid: an integration of high resolution hydro-acoustic data and sediment cores

    K. Lindhorst

    2010-05-01

    Full Text Available Ancient Lake Ohrid is a steep sided, oligotrophic, karst lake of likely Pliocene age and often referred to as a hotspot of endemic biodiversity. This study aims on tracing significant lake level fluctuations at Lake Ohrid using high-resolution acoustic data in combination with lithological, geochemical, and chronological information from two sediment cores recovered from sub-aquatic terrace levels at ca. 32 and 55 m. According to our data, significant lake level fluctuations with prominent lowstands of ca. 60 and 35 m below the present water level occurred during MIS 6 and MIS 5, respectively. The effect of these lowstands on biodiversity in most coastal parts of the lake is negligible, due to only small changes in lake surface area, coastline, and habitat. In contrast, biodiversity in shallower areas was more severely affected due to disconnection of today sub-lacustrine springs from the main water body. Multichannel seismic data from deeper parts of the lake clearly imaged several clinoform structures stacked on top of each other. These stacked clinoforms indicate significantly lower lake levels prior to MIS 6 and a stepwise rise of water level with intermittent stillstands since its existence as water filled body, which might have caused enhanced expansion of endemic species within Lake Ohrid.

  16. Stratigraphic analysis of lake level fluctuations in Lake Ohrid: an integration of high resolution hydro-acoustic data and sediment cores

    K. Lindhorst

    2010-11-01

    Full Text Available Ancient Lake Ohrid is a steep-sided, oligotrophic, karst lake that was tectonically formed most likely within the Pliocene and often referred to as a hotspot of endemic biodiversity. This study aims on tracing significant lake level fluctuations at Lake Ohrid using high-resolution acoustic data in combination with lithological, geochemical, and chronological information from two sediment cores recovered from sub-aquatic terrace levels at ca. 32 and 60 m water depth. According to our data, significant lake level fluctuations with prominent lowstands of ca. 60 and 35 m below the present water level occurred during Marine Isotope Stage (MIS 6 and MIS 5, respectively. The effect of these lowstands on biodiversity in most coastal parts of the lake is negligible, due to only small changes in lake surface area, coastline, and habitat. In contrast, biodiversity in shallower areas was more severely affected due to disconnection of today sub-lacustrine springs from the main water body. Multichannel seismic data from deeper parts of the lake clearly image several clinoform structures stacked on top of each other. These stacked clinoforms indicate significantly lower lake levels prior to MIS 6 and a stepwise rise of water level with intermittent stillstands since its existence as water-filled body, which might have caused enhanced expansion of endemic species within Lake Ohrid.

  17. Stratigraphic analysis of lake level fluctuations in Lake Ohrid: an integration of high resolution hydro-acoustic data and sediment cores

    Lindhorst, K.; Vogel, H.; Krastel, S.; Wagner, B.; Hilgers, A.; Zander, A.; Schwenk, T.; Wessels, M.; Daut, G.

    2010-11-01

    Ancient Lake Ohrid is a steep-sided, oligotrophic, karst lake that was tectonically formed most likely within the Pliocene and often referred to as a hotspot of endemic biodiversity. This study aims on tracing significant lake level fluctuations at Lake Ohrid using high-resolution acoustic data in combination with lithological, geochemical, and chronological information from two sediment cores recovered from sub-aquatic terrace levels at ca. 32 and 60 m water depth. According to our data, significant lake level fluctuations with prominent lowstands of ca. 60 and 35 m below the present water level occurred during Marine Isotope Stage (MIS) 6 and MIS 5, respectively. The effect of these lowstands on biodiversity in most coastal parts of the lake is negligible, due to only small changes in lake surface area, coastline, and habitat. In contrast, biodiversity in shallower areas was more severely affected due to disconnection of today sub-lacustrine springs from the main water body. Multichannel seismic data from deeper parts of the lake clearly image several clinoform structures stacked on top of each other. These stacked clinoforms indicate significantly lower lake levels prior to MIS 6 and a stepwise rise of water level with intermittent stillstands since its existence as water-filled body, which might have caused enhanced expansion of endemic species within Lake Ohrid.

  18. Quantum chaos in ultracold collisions between Yb($^1$S$_0$) and Yb($^3$P$_2$)

    Green, Dermot G; Frye, Matthew D; Morita, Masato; Hutson, Jeremy M

    2015-01-01

    We calculate and analyze Feshbach resonance spectra for ultracold Yb($^1$S$_0$) + Yb($^3$P$_2$) collisions as a function of an interatomic potential scaling factor $\\lambda$ and external magnetic field. We show that, at zero field, the resonances are distributed randomly in $\\lambda$, but that signatures of quantum chaos emerge as a field is applied. The random zero-field distribution arises from superposition of structured spectra associated with individual total angular momenta. In addition, we show that the resonances in magnetic field in the experimentally accessible range 400 to 2000~G are chaotically distributed, with strong level repulsion that is characteristic of quantum chaos.

  19. Structural origin of Si-2p core-level shifts from Si(100)-c[4x2] surface: A spectral x-ray photoelectron diffraction study

    Chen, X.; Tonner, B.P. [Univ. of Wisconsin, Milwaukee, WI (United States); Denlinger, J. [Univ. of Wisconsin, Milwaukee, WI (United States)][Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    The authors have performed angle-resolved x-ray photoelectron diffraction (XPD) from a Si(100)-c(4x2) surface to study the structural origin of Si-2p core-level shifts. In the experiment, the highly resolved surface Si-2p core-level spectra were measured as a fine grid of hemisphere and photon energies, using the SpectroMicroscopy Facility {open_quotes}ultraESCA{close_quotes} instrument. By carefully decomposing the spectra into several surface peaks, the authors are able to obtain surface-atom resolved XPD patterns. Using a multiple scattering analysis, they derived a detailed atomic model for the Si(100)-c(4x2) surface. In this model, the asymmetric dimers were found tilted by 11.5 plus/minus 2.0 degrees with bond length of 2.32 plus/minus 0.05{angstrom}. By matching model XPD patterns to experiment, the authors can identify which atoms in the reconstructed surface are responsible for specific photoemission lines in the 2p spectrum.

  20. Coverage dependent organic-metal interaction studied by high-resolution core level spectroscopy: SnPc (sub)monolayers on Ag(1 1 1)

    Haeming, M.; Scheuermann, C. [Experimentelle Physik II, Universitaet Wuerzburg, D-97074 Wuerzburg (Germany); Schoell, A. [Experimentelle Physik II, Universitaet Wuerzburg, D-97074 Wuerzburg (Germany); Forschungszentrum Karlsruhe, Gemeinschaftslabor fuer Nanoanalytik, D-76021 Karlsruhe (Germany)], E-mail: achim.schoell@physik.uni-wuerzburg.de; Reinert, F. [Experimentelle Physik II, Universitaet Wuerzburg, D-97074 Wuerzburg (Germany); Forschungszentrum Karlsruhe, Gemeinschaftslabor fuer Nanoanalytik, D-76021 Karlsruhe (Germany); Umbach, E. [Experimentelle Physik II, Universitaet Wuerzburg, D-97074 Wuerzburg (Germany); Forschungszentrum Karlsruhe and Karlsruhe Institute of Technology, Weberstrasse 5, D-76021 Karlsruhe (Germany)

    2009-08-15

    We study the electronic structure of tin-phthalocyanine (SnPc) molecules adsorbed on a Ag(1 1 1) surface by high-resolution photoelectron spectroscopy. We particularly address the effect of different SnPc coverages on the interaction and charge transfer at the interface. The results give evidence for a covalent molecule-substrate interaction, which is temperature and coverage dependent. The valence and core level spectra as well as the work function measurements allow us monitoring subtle differences in the strength of the interface interaction, thus demonstrating the sensitivity of the methods. The results consistently show the effect of charge exchange between substrate and molecules which obviously leads to a net charge transfer into the SnPc molecules, and which is increased with decreasing coverage. Surprisingly, the Sn3d core levels are neither effected by variations of charge transfer and interaction strength, nor by a possible 'Sn-up' or 'Sn-down' orientation, which have been observed for sub-monolayers.

  1. Investigation of the maximal values of the fuel surface temperatures in the active zone of the Dalat research reactor for operating core configuration of 89 fuel assembles and fundamental core configuration of 94 fuel assembles at limited power level of 550 kW

    Calculation for defining the maximal values of fuel surface temperature in active zone of the Dalat nuclear research reactor (DNRR) is one of the important items in Safety Analyses for the reactor. The operating core configuration of 89 VVR-M2 fuel assemblies and fundamental core configuration of 94 fuel assemblies are used. The reactor is on limited power level of 550 kW. The calculated results for different operating core configuration and fundamental core configuration of 94 fuel assemblies and the comparison with the experimental data received on the DNRR and other data are reasonable. (author)

  2. Radiative rates for E1, E2, M1, and M2 transitions among the 3s$^2$3p$^5$, 3s3p$^6$, and 3s$^2$3p$^4$3d configurations of Cl-like W LVIII

    Aggarwal, K M

    2014-01-01

    We report calculations of energy levels, radiative decay rates, and lifetimes for transitions among the 3s$^2$3p$^5$, 3s3p$^6$, and 3s$^2$3p$^4$3d configurations of Cl-like W LVIII. The general-purpose relativistic atomic structure package (GRASP) has been adopted for our calculations. Comparisons are made with the most recent results of Mohan et al. [Can. J. Phys. {\\bf 92} (2014) xxx] and discrepancies in lifetimes are noted, up to four orders of magnitude in some instances. Our energy levels are estimated to be accurate to better than 0.5\\%, whereas results for radiative rates and lifetimes should be accurate to better than 20\\%.

  3. Proteomics Core

    Federal Laboratory Consortium — Proteomics Core is the central resource for mass spectrometry based proteomics within the NHLBI. The Core staff help collaborators design proteomics experiments in...

  4. Electron-energy-loss spectroscopy of KxC60 and K-halides: comparison in the K-3p excitation region

    上野, 啓司; 斉木, 幸一朗; 小間, 篤

    2001-01-01

    We have investigated the electronic structure of KxC60 (x = 0-6) using low-energy electron energy loss spectroscopy (LEELS), especially focusing on the K-3p core-electron excitation spectra. It is found that the structure of the K-3p-excitation spectrum of KxC60 quite differs from that of KCI. Furthermore, the K-3p-excitation LEELS of K3C60 has been revealed to be different from that of K6C60. K-3p electrons are excited into K-4s- and K-3d-derived empty states in both KxC60 and KCI, but in th...

  5. Rapid measurement of perchlorate in polar ice cores down to sub-ng L(-1) levels without pre-concentration.

    Peterson, Kari; Cole-Dai, Jihong; Brandis, Derek; Cox, Thomas; Splett, Scott

    2015-10-01

    An ion chromatography-electrospray ionization-tandem mass spectrometry (IC-ESI-MS/MS) method has been developed for rapid and accurate measurement of perchlorate in polar snow and ice core samples in which perchlorate concentrations are expected to be as low as 0.1 ng L(-1). Separation of perchlorate from major inorganic species in snow is achieved with an ion chromatography system interfaced to an AB SCIEX triple quadrupole mass spectrometer operating in multiple reaction monitoring mode. Under optimized conditions, the limit of detection and lower limit of quantification without pre-concentration have been determined to be 0.1 and 0.3 ng L(-1), respectively, with a linear dynamic range of 0.3-10.0 ng L(-1) in routine measurement. These represent improvements over previously reported methods using similar analytical techniques. The improved method allows fast, accurate, and reproducible perchlorate quantification down to the sub-ng L(-1) level and will facilitate perchlorate measurement in the study of natural perchlorate production with polar ice cores in which perchlorate concentrations are anticipated to vary in the low and sub-ng L(-1) range. Initial measurements of perchlorate in ice core samples from central Greenland show that typical perchlorate concentrations in snow dated prior to the Industrial Revolution are about 0.8 ng L(-1), while perchlorate concentrations are significantly higher in recent (post-1980) snow, suggesting that anthropogenic sources are a significant contributor to perchlorate in the current environment. PMID:26297465

  6. Up- regulation of miR-328-3p sensitizes non-small cell lung cancer to radiotherapy.

    Ma, Wei; Ma, Chao-Nan; Zhou, Nan-Nan; Li, Xian-Dong; Zhang, Yi-Jie

    2016-01-01

    MicroRNAs (miRNAs) are believed to be resistant against radiotherapy in certain types of cancers. The aim of our study was to determine the clinical application of miRNAs in non-small cell lung cancer (NSCLC). Sixty NSCLC tissue samples and adjacent histologically normal tissues were obtained for miRNAs microarray analysis and validated by RT-qPCR. Correlation between miRNA expression level and clinicopathological features was evaluated. Our study examined the influence of changed miRNA expression on the damaged DNA and its associated radio sensitivity. Luciferase assay was performed to determine potential effects on the targeted gene. Our study identified fifteen altered miRNAs in which miR-328-3p was down regulated in NSCLC tumour tissue as compared to normal tissues. Down-expression of miR-328-3p was positively associated with an enhanced lymph node metastasis, advanced clinical stage and a shortened survival rate. miR-328-3p expression was decreased in A549 cells compared to other NSCLC cell lines. Up-regulation of miR-328-3p demonstrated a survival inhibition effect in A549 and restored NSCLC cells' sensitivity to radio therapy. An increased miR-328-3p expression promoted irradiation-induced DNA damage in cells. γ-H2AX was identified as the direct target of miR-328-3p. Over-expressed miR-328-3p can improve the radiosensitvity of cells by altering the DNA damage/repair signalling pathways in NSCLC. PMID:27530148

  7. 'Oxygen' effect in ionization loss spectrum of Cu3p in YBa2Cu3Ox ceramics

    YBaCu3Ox ceramic samples with different oxygen concentration (6.2; 6.5 and 6.9) in a volume are investigated. The process of degradation of samples with high X in the vacuum is analyzed. The surface purification is performed through scribing in argon atmosphere. A new effect is ascertained which is manifested in high sensitivity of Cu3p ionization loss spectrum to the density of the non-occupied electron states at the Fermi level. It is shown that Cu3p ionization spectrum can serve as a new criterion of superconductor surface quality from the viewpoint of its electronic structure

  8. Systems-Level Response to Point Mutations in a Core Metabolic Enzyme Modulates Genotype-Phenotype Relationship

    Shimon Bershtein

    2015-04-01

    Full Text Available Linking the molecular effects of mutations to fitness is central to understanding evolutionary dynamics. Here, we establish a quantitative relation between the global effect of mutations on the E. coli proteome and bacterial fitness. We created E. coli strains with specific destabilizing mutations in the chromosomal folA gene encoding dihydrofolate reductase (DHFR and quantified the ensuing changes in the abundances of 2,000+ E. coli proteins in mutant strains using tandem mass tags with subsequent LC-MS/MS. mRNA abundances in the same E. coli strains were also quantified. The proteomic effects of mutations in DHFR are quantitatively linked to phenotype: the SDs of the distributions of logarithms of relative (to WT protein abundances anticorrelate with bacterial growth rates. Proteomes hierarchically cluster first by media conditions, and within each condition, by the severity of the perturbation to DHFR function. These results highlight the importance of a systems-level layer in the genotype-phenotype relationship.

  9. Warm Core Structure and Mid-Level Intrusion in Hurricane Bonnie (1998) During Landfalling on 26 August 1998

    Heymsfield, G. M.; Halverson, J.

    2004-01-01

    On 26 August 1998 during CAMEX-3, Hurricane Bonnie was overflown by the NASA ER-2 aircraft instrumented with the EDOP X-Band radar and other instrumentation. Bonnie was an asymmetric storm on this day with several prominent features during its brush with the East coast. One of these features was strong intrusion of dry air on the west side of the storm. During the interaction of this westerly shear with the storm, the precipitation band rotates cyclonically from northwest to the south of the storm center. In this paper, we examine the structure of this dry intrusion and its effect on the storm. The EDOP observations are analyzed along with dropsondes, flight-level observations (NASA DC-8 and NOAA P3), and satellite data. The most apparent feature of the EDOP observations are the strong shears in the interface between the western eyewall updraft, and the dry intrusion. Mammatus are formed along this interface reminiscent of convective rear inflows, and suggestive of intense drying of the air through subsidence. This observation as well as other aspects of the analysis are related to recent numerical simulations of Hurricane Bonnie.

  10. Semi-analytic ray tracing method for time-efficient computing of transmission behavior of PCB level optical interconnects with varying core cross sections

    Stübbe, Oliver

    2015-03-01

    Optical interconnects on printed circuit board level are a promising choice to support high bandwidth for short distance interconnects. These interconnects consists of highly multimode step index waveguides with rectangular core cross sections. Therefore ray tracing is an excellent method to determine the optical path parameters, e.g. optical power, ray path lengths and local ray directions. Based on these parameters the step response, the transient transfer function and the coupling behavior can be calculated. Classical ray tracing methods calculates the optical path parameters of each ray by successively computing internal reflections until a termination condition is reached. Therefore the computing time depends on the number of internal reflections. If the optical waveguide consists of cascaded straight and curved segments, e. g. point-to-point interconnects, one can use the analytic ray tracing method to determine the optical path parameters. The whole path parameters of each ray are determined by one analytical computation. The computing time depends on the number of segments. The analytic ray tracing method is unusable to determine ray path parameters of segments with varying core cross sections, e.g. tapers, crossings, splitters and combiners.

  11. A multi-level surface rebalancing approach for efficient convergence acceleration of 3D full core multi-group fine grid nodal diffusion iterations

    Highlights: • New type of multi-level rebalancing approach for nodal transport. • Generally improved and more mesh-independent convergence behavior. • Importance for intended regime of 3D pin-by-pin core computations. - Abstract: A new multi-level surface rebalancing (MLSR) approach has been developed, aimed at enabling an improved non-linear acceleration of nodal flux iteration convergence in 3D steady-state and transient reactor simulation. This development is meant specifically for anticipating computational needs for solving envisaged multi-group diffusion-like SPN calculations with enhanced mesh resolution (i.e. 3D multi-box up to 3D pin-by-pin grid). For the latter grid refinement regime, the previously available multi-level coarse mesh rebalancing (MLCMR) strategy has been observed to become increasingly inefficient with increasing 3D mesh resolution. Furthermore, for very fine 3D grids that feature a very fine axial mesh as well, non-convergence phenomena have been observed to emerge. In the verifications pursued up to now, these problems have been resolved by the new approach. The novelty arises from taking the interface current balance equations defined over all Cartesian box edges, instead of the nodal volume-integrated process-rate balance equation, as an appropriate restriction basis for setting up multi-level acceleration of fine grid interface current iterations. The new restriction strategy calls for the use of a newly derived set of adjoint spectral equations that are needed for computing a limited set of spectral response vectors per node. This enables a straightforward determination of group-condensed interface current spectral coupling operators that are of crucial relevance in the new rebalancing setup. Another novelty in the approach is a new variational method for computing the neutronic eigenvalue. Within this context, the latter is treated as a control parameter for driving another, newly defined and numerically more fundamental

  12. Na*(3p)-Formation under grazing scattering of Na[sup +]-ions at an Al(111) surface

    Zimny, R. (Inst. fuer Kernphysik, Univ. Muenster (Germany)); Borisov, A.G. (Dept. of Physics, Moscow State Univ. (Russian Federation))

    1994-06-01

    Excited Na*(3p)-atoms are observed in grazing surface-collision experiments with Na[sup +]-beams. Such atoms can be formed beyond a certain threshold velocity via resonant electron transfer between atomic and metallic conduction band levels due to motion of the atom relative to the surface of the metal (''kinematic resonance''). This mechanism is studied here theoretically employing two different techniques: the nonperturbative ''Coupled Angular Mode'' (CAM) method and the approximate ''Transfer Hamiltonian'' (TH) method. The calculated Na*(3p)-populations agree well with recent experimental results. Moreover, the complete density matrix of the Na*(3p)-subspace has been computed with the TH-method for ion-energies between 10 and 300 keV. (orig.)

  13. LWR Thorium-Based Equilibrium-TRU (TRU-sustainable) Fuel Cycle: From 2D Fuel Lattice Model to the Full 3D Core Level Model

    A study was performed in the BNL to investigate LWR thorium-based equilibrium-TRU (TRU-sustainable) fuel cycle. In such a self-sustainable fuel cycle, only TRU lost by the fuel separation activities passes to the repository. The equilibrium transuranics inventory is recycled into each subsequent reload. Results of the study demonstrate the neutronic feasibility of a fuel cycle with ''zero-TRU'' discharge. A limitation of this study is the fact that a 2D fuel lattice model was used, specifically, the linear reactivity model, applied to the results of assembly calculations, assumes a single fuel type for all three batches. Thus, the end result of this work is a confirmation of the possibility of establishing equilibrium TRU fuel cycle via the full 3D core level calculational model

  14. Core level photoemission spectroscopy and chemical bonding in Sr2Ta2O7

    Atuchin, V. V.; Grivel, Jean-Claude; Zhang, Z. M.

    2009-01-01

    -O bonds was characterized by the binding energy differences between the O 1s and cation core levels, Delta(O-Sr) = BE(O 1s) - BE(Sr 3d(5/2)) and Delta(O-Ta) = BE(O 1s) - BE(Ta 4f(7/2)). The chemical bonding effects were considered on the basis of our XPS results for Sr2Ta2O7 and earlier published...... structural and XPS data for other Sr- and Ta-containing oxide compounds. The new data point for Sr2Ta2O7 is consistent with the previously derived relationship for a set of Sr-bearing oxides. The binding energy difference Delta(O-Sr) was found to decrease with increasing bond distance L(Sr-O)....

  15. A suggested emergency medicine boot camp curriculum for medical students based on the mapping of Core Entrustable Professional Activities to Emergency Medicine Level 1 milestones

    Lamba S

    2016-03-01

    Full Text Available Sangeeta Lamba, Bryan Wilson, Brenda Natal, Roxanne Nagurka, Michael Anana, Harsh Sule Department of Emergency Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA Background: An increasing number of students rank Emergency Medicine (EM as a top specialty choice, requiring medical schools to provide adequate exposure to EM. The Core Entrustable Professional Activities (EPAs for Entering Residency by the Association of American Medical Colleges combined with the Milestone Project for EM residency training has attempted to standardize the undergraduate and graduate medical education goals. However, it remains unclear as to how the EPAs correlate to the milestones, and who owns the process of ensuring that an entering EM resident has competency at a certain minimum level. Recent trends establishing specialty-specific boot camps prepare students for residency and address the variability of skills of students coming from different medical schools. Objective: Our project’s goal was therefore to perform a needs assessment to inform the design of an EM boot camp curriculum. Toward this goal, we 1 mapped the core EPAs for graduating medical students to the EM residency Level 1 milestones in order to identify the possible gaps/needs and 2 conducted a pilot procedure workshop that was designed to address some of the identified gaps/needs in procedural skills. Methods: In order to inform the curriculum of an EM boot camp, we used a systematic approach to 1 identify gaps between the EPAs and EM milestones (Level 1 and 2 determine what essential and supplemental competencies/skills an incoming EM resident should ideally possess. We then piloted a 1-day, three-station advanced ABCs procedure workshop based on the identified needs. A pre-workshop test and survey assessed knowledge, preparedness, confidence, and perceived competence. A post-workshop survey evaluated the program, and a posttest combined with psychomotor skills test using three

  16. Mechanisms and Kinetics of Radical Reaction of O(1D,3P) + HCN System

    HUANG Yu-Cheng; DU Jin-Yan; JU Xue-Hai; YE Shi-Yong; ZHOU Tao

    2008-01-01

    The reaction of HCN with O(1D, 3P) radical has been investigated by density functional theory (DFT) and ab initio methods. The stationary points on the reaction paths(reactants, intermediates and products) were optimized at the (U)B3LYP/aug-cc-pVTZ level.Single-point calculations were performed at the (U)QCISD(T)/aug-cc-pVTZ level for the optimized structures and all the total energies were corrected by zero-point energy. It is shown that there exist three competing mechanisms of oxygen attacking nitrogen O→N, oxygen attacking carbon O→C and oxygen attacking hydrogen O→H. The rate constants were obtained via Eyring transition-state theory in the temperature range of 600~2000 K. The linear relationship between lnk and 1/T was presented. The results show that path 1 is the main reaction channel and the product of NCO + H is predominant.

  17. Puf3p, a Pumilio family RNA binding protein, localizes to mitochondria and regulates mitochondrial biogenesis and motility in budding yeast

    García-Rodríguez, Luis J.; Gay, Anna Card; Pon, Liza A.

    2007-01-01

    Puf3p binds preferentially to messenger RNAs (mRNAs) for nuclear-encoded mitochondrial proteins. We find that Puf3p localizes to the cytosolic face of the mitochondrial outer membrane. Overexpression of PUF3 results in reduced mitochondrial respiratory activity and reduced levels of Pet123p, a protein encoded by a Puf3p-binding mRNA. Puf3p levels are reduced during the diauxic shift and growth on a nonfermentable carbon source, conditions that stimulate mitochondrial biogenesis. These findings support a role for Puf3p in mitochondrial biogenesis through effects on mRNA interactions. In addition, Puf3p links the mitochore, a complex required for mitochondrial–cytoskeletal interactions, to the Arp2/3 complex, the force generator for actin-dependent, bud-directed mitochondrial movement. Puf3p, the mitochore, and the Arp2/3 complex coimmunoprecipitate and have two-hybrid interactions. Moreover, deletion of PUF3 results in reduced interaction between the mitochore and the Arp2/3 complex and defects in mitochondrial morphology and motility similar to those observed in Arp2/3 complex mutants. Thus, Puf3p is a mitochondrial protein that contributes to the biogenesis and motility of the organelle. PMID:17210948

  18. Line shape and composition of the In 3d5/2 core-level photoemission for the interface analysis of In-containing III–V semiconductors

    Highlights: • Photoelectron study of the controversial In 3d line shape of III–V semiconductors. • The spectral envelope is found to be fit well by a combination of symmetric peaks. • The energy band gap has no effect on the spectral features of In 3d peak. • In 3d emissions are described well with reconstruction-induced core-level shifts. • The results are important to photoelectron studies of the III–V device materials. - Abstract: The In 3d5/2 photoelectron spectroscopy peak has been widely used to determine the interface structures of In-containing III–V device materials (e.g., oxidation states). However, an unclear parameter affecting the determination of the energy shifts and number of the core-level components, and therefore, the interpreted interface structure and composition, is still the intrinsic In 3d5/2 peak line shape. It is undecided whether the line shape is naturally symmetric or asymmetric for pure In-containing III–V compounds. By using high-resolution photoelectron spectroscopy, we show that the In 3d5/2 asymmetry arising from the emission at high binding-energy tail is not an intrinsic property of InAs, InP, InSb and InGaAs. Furthermore, it is shown that asymmetry of In 3d5/2 peaks of pure III–V's originates from the natural surface reconstructions which cause the coexistence of slightly shifted In 3d5/2 components with the symmetric peak shape and dominant Lorentzian broadening

  19. Liver MicroRNA-291b-3p Promotes Hepatic Lipogenesis through Negative Regulation of Adenosine 5'-Monophosphate (AMP)-activated Protein Kinase α1.

    Meng, Xiangyu; Guo, Jun; Fang, Weiwei; Dou, Lin; Li, Meng; Huang, Xiuqing; Zhou, Shutong; Man, Yong; Tang, Weiqing; Yu, Liqing; Li, Jian

    2016-05-13

    In a microarray study, we found that hepatic miR-291b-3p was significantly increased in leptin-receptor-deficient type 2 mice (db/db), a mouse model of diabetes. The function of miR-291b-3p is unknown. The potential role of miR-291b-3p in regulating hepatic lipid metabolism was explored in this study. High-fat diet (HFD)- and chow-fed mice were injected with an adenovirus expressing a miR-291b-3p inhibitor and a miR-291b-3p mimic through the tail vein. Hepatic lipids and lipogenic gene expression were analyzed. Additionally, gain- and loss-of-function studies were performed in vitro to identify direct targets of miR-291b-3p. MiR-291b-3p expression and the protein levels of sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FAS) were increased in the steatotic liver of db/db mice and HFD-fed mice versus their respective controls. Inhibition of hepatic miR-291b-3p expression prevented increases in hepatic lipogenesis and steatosis in HFD-fed mice. The opposite was observed when miR-291b-3p was overexpressed in the livers of chow-fed C57BL/6J wild-type mice. In vitro studies revealed that silencing of miR-291b-3p in NCTC1469 hepatic cells ameliorated oleic acid/palmitic acid mixture-induced elevation of cellular triglycerides. Importantly, we identified AMP-activated protein kinase (AMPK)-α1 as a direct target of miR-291b-3p. Using metformin, an activator of AMPK, we showed that AMPK activation-induced inhibition of hepatic lipid accumulation was accompanied by reduced expression of miR-291b-3p in the liver. Liver miR-291b-3p promoted hepatic lipogenesis and lipid accumulation in mice. AMPKα1 is a direct target of miR-291b-3p. In conclusion, our findings indicate that miR-291b-3p promotes hepatic lipogenesis by suppressing AMPKα1 expression and activity, indicating the therapeutic potential of miR-291b-3p inhibitors in fatty liver disease. PMID:27013659

  20. Greenland ice sheet contribution to sea level rise during the last interglacial period: a modelling study driven and constrained by ice core data

    A. Quiquet

    2013-02-01

    Full Text Available As pointed out by the forth assessment report of the Intergovernmental Panel on Climate Change, IPCC-AR4 (Meehl et al., 2007, the contribution of the two major ice sheets, Antarctica and Greenland, to global sea level rise, is a subject of key importance for the scientific community. By the end of the next century, a 3–5 °C warming is expected in Greenland. Similar temperatures in this region were reached during the last interglacial (LIG period, 130–115 ka BP, due to a change in orbital configuration rather than to an anthropogenic forcing. Ice core evidence suggests that the Greenland ice sheet (GIS survived this warm period, but great uncertainties remain about the total Greenland ice reduction during the LIG. Here we perform long-term simulations of the GIS using an improved ice sheet model. Both the methodologies chosen to reconstruct palaeoclimate and to calibrate the model are strongly based on proxy data. We suggest a relatively low contribution to LIG sea level rise from Greenland melting, ranging from 0.7 to 1.5 m of sea level equivalent, contrasting with previous studies. Our results suggest an important contribution of the Antarctic ice sheet to the LIG highstand.

  1. Experimental transition probabilities of the intercombination line 1s2ws21S0-1s22s3p3P01 in Be-like ions of Na through Si

    The decay of the 1s22s3p3 Po0,1,2 levels in Be-like ions of Na, Mg, Al and Si has been investigated using the beam-foil method. The mean wavelengths of the transition 1s22p23P0,1,2-1s22s3p 3Po0,1,2 and the lifetimes of the 1s22s3p 3Po0,1,2 levels have been measured. An intercomparison of these lifetimes yields the transition probability of the intercombination line 1s22s21S0-1s22s3p 3Po1. The results are (3.45 ± 0.73) 109 s-1 in Na VIII, (5.55 ± 0.96) 109 s-1 in Mg IX, (1.21 ± 0.24) 1010 s-1 in Al X and (2.50 ± 0.54) 1010 s-1 in Si XI. (orig.)

  2. Role of miR-222-3p in c-Src-Mediated Regulation of Osteoclastogenesis

    Shinya Takigawa

    2016-02-01

    Full Text Available MicroRNAs (miRNAs are small non-coding RNAs that play a mostly post-transcriptional regulatory role in gene expression. Using RAW264.7 pre-osteoclast cells and genome-wide expression analysis, we identified a set of miRNAs that are involved in osteoclastogenesis. Based on in silico analysis, we specifically focused on miR-222-3p and evaluated its role in osteoclastogenesis. The results show that the inhibitor of miR-222-3p upregulated the mRNA levels of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1 and tartrate-resistant acid phosphatase (TRAP, while its mimicking agent downregulated their mRNA levels. Western blot analysis showed that its inhibitor increased the protein levels of TRAP and cathepsin K, while its mimicking agent decreased their levels. Genome-wide mRNA expression analysis in the presence and absence of receptor activator of nuclear factor κ-B ligand (RANKL predicted c-Src as a potential regulatory target of miR-222-3p. Live cell imaging using a fluorescence resonance energy transfer (FRET technique revealed that miR-222-3p acted as an inhibitor of c-Src activity, and a partial silencing of c-Src suppressed RANKL-induced expression of TRAP and cathepsin K, as well as the number of multi-nucleated osteoclasts and their pit formation. Collectively, the study herein demonstrates that miR-222-3p serves as an inhibitor of osteoclastogenesis and c-Src mediates its inhibition of cathepsin K and TRAP.

  3. Nascent 60S ribosomal subunits enter the free pool bound by Nmd3p.

    Ho, J. H.; Kallstrom, G; Johnson, A. W.

    2000-01-01

    Nmd3p from yeast is required for the export of the large (60S) ribosomal subunit from the nucleus (Ho et al., 2000). Here, we show that Nmd3p forms a stable complex with free 60S subunits. Using an epitope-tagged Nmd3p, we show that free 60S subunits can be coimmunoprecipitated with Nmd3p. The interaction was specific for 60S subunits; 40S subunits were not coimmunoprecipitated. Using this coprecipitation technique and pulse-chase labeling of ribosomal subunit proteins we showed that Nmd3p bo...

  4. MicroRNA-219-2-3p functions as a tumor suppressor in gastric cancer and is regulated by DNA methylation.

    Huizi Lei

    Full Text Available BACKGROUND AIMS: Gastric cancer is the most frequent gastrointestinal tumor in adults and is the most lethal form of human cancer. Despite of the improvements in treatments, the underlying mechanism of gastric carcinogenesis is not well known. To define novel modulators that regulate susceptibility to tumorgenesis, we focused on miR-219-2-3p. METHODS: Quantitative RT-PCR was employed to investigate the level of miR-219-2-3p in gastric cancer (GC tissues (n = 113 and their matched adjacent normal tissues (n = 113. In vitro cell proliferation, apoptosis assays, cell migration, and invasion assays were performed to elucidate biological effects of miR-219-2-3p. Since silencing of miRNA by promoter CpG island methylation may be an important mechanism in tumorgenesis, GC cells were treated with 5-aza-2'-deoxycytidine and trichostatin A, and expression changes of miR-219-2-3p were subsequently examined by quantitative RT-PCR. Finally, the methylation status of CpG island upstream of miR-219-2-3p was analyzed by methylation-specific PCR in GC tissues (n = 22. RESULTS: miR-219-2-3p was down-regulated in GC and cell lines. In addition, the experiments documented the lower expression of miR-219-2-3p in GC specimens with higher grade and later stage tumors. Meanwhile, miR-219-2-3p exerted antiproliferative, proapoptotic, and antimetastatic roles and reduced levels of p-ERK1/2 in GC cells. Furthermore, 5-aza-2'-deoxycytidine and trichostatin A increased the expression (~2 fold of miR-219-2-3p in GC cells. By methylation-specific PCR, DNA methylation in the upstream region of miR-219-2-3p was detected in both adjacent normal tissues and cancer tissues. As expected, the methylation level was considerably higher in the miR-219-2-3p down-regulated group than up-regulated group. CONCLUSIONS: miR-219-2-3p is potentially involved in gastric cancer progression and metastasis by regulating ERK1/2-related signal pathways, which may provide a novel therapeutic strategy

  5. Circulating miR-221-3p as a novel marker for early prediction of acute myocardial infarction.

    Coskunpinar, Ender; Cakmak, Huseyin Altug; Kalkan, Ali Kemal; Tiryakioglu, Necip Ozan; Erturk, Mehmet; Ongen, Zeki

    2016-10-10

    Recent studies have reported circulating microRNAs (miRNAs) as novel biomarkers for cardiovascular diseases including acute myocardial infarction, heart failure, diabetes mellitus, stroke, and acute pulmonary embolism. The aims of this study were 1) to compare the plasma expression levels of miRNAs in patients with acute coronary syndrome (ACS) and control subjects and in ST-elevation myocardial infarction (STEMI) and non-STEMI 2) to evaluate miRNAs potential to be used as novel diagnostic biomarkers for ACS. Twenty seven consecutive patients, admitted to emergency department of a training and research hospital between January-December 2013 with acute chest pain and/or dyspnea and diagnosed with ACS, and 16 non-ACS control subjects were included in this study. miRNA profiling was performed by using real time polymerase chain reaction. Functions of dysregulated miRNAs were evaluated by computerized-pathways analysis. miR-221-3p was one of the two most dysregulated miRNAs with a fold regulation of 3.89. It was significantly positively correlated with both Troponin and GRACE and Synthax Score. Moreover, miR221-3p was found to be significantly inversely correlated with left ventricular ejection fraction. miR-221-3p was the most prominent biomarker candidate with an area under curve (AUC) level of 0.881 (95% confidence interval: 0.774-0.987; p=0.002). The present study is the first to report an increased expression levels of miR-221-3p in AMI. Since miR-221-3p has a high discriminative value and significant relations with Troponin, GRACE and Synthax score and left ventricular systolic function, it may be a potential biomarker for early prediction of AMI. PMID:27374153

  6. Young's double-slit experiment using core-level photoemission from N2: revisiting Cohen-Fano's two-centre interference phenomenon

    The core-level photoelectron spectra of N2 molecules are observed at high energy resolution, resolving the 1σg and 1σu components as well as the vibrational components in the extended energy region from the threshold up to 1 keV. The σg/σu cross section ratios display modulation as a function of photoelectron momentum due to the two-centre interference, analogous to the classical Young's double-slit experiment, as predicted by Cohen and Fano a long time ago. The Cohen-Fano interference modulations display different phases depending on the vibrational excitations in the core-ionized state. Extensive ab initio calculations have been performed within the Hartree-Fock and random phase approximations in prolate spheroidal coordinates. The dependence of photoionization amplitudes on the vibrational states was taken into account using the Born-Oppenheimer approximation. The ab initio results are in reasonable agreement with the experimental data. The theoretical analysis allows the modulation to be connected with the onset of transitions to the states of increasing orbital angular momentum which occurs at increasing photon energies. Deviation from the Cohen-Fano formula is found for both the experimental and the ab initio results and is attributed to electron scattering by the neighbouring atom. A new formula for the interference modulation is derived within the framework of the multiple scattering technique. It differs from the classical Cohen-Fano formula by the addition of twice the scattering phase of the photoelectron by the neighbouring atom. We demonstrate that one can measure directly the scattering phase by fitting our formula to the experimental results

  7. Tretinoin-loaded lipid-core nanocapsules decrease reactive oxygen species levels and improve bovine embryonic development during in vitro oocyte maturation.

    Lucas, Caroline Gomes; Remião, Mariana Härter; Komninou, Eliza Rossi; Domingues, William Borges; Haas, Cristina; Leon, Priscila Marques Moura de; Campos, Vinicius Farias; Ourique, Aline; Guterres, Silvia S; Pohlmann, Adriana R; Basso, Andrea Cristina; Seixas, Fabiana Kömmling; Beck, Ruy Carlos Ruver; Collares, Tiago

    2015-12-01

    In vitro oocyte maturation (IVM) protocols can be improved by adding chemical supplements to the culture media. Tretinoin is considered an important retinoid in embryonic development and its association with lipid-core nanocapsules (TTN-LNC) represents an innovative way of improving its solubility, and chemical stability, and reducing its toxicity. The effects of supplementing IVM medium with TTN-LNC was evaluated by analyzing production of reactive oxygen species (ROS), S36-phosphorilated-p66Shc levels and caspase activity in early embryonic development, and expression of apoptosis and pluripotency genes in blastocysts. The lowest concentration tested (0.25μM) of TTN-LNC generated higher blastocyst rate, lower ROS production and S36-p66Shc amount. Additionally, expression of BAX and SHC1 were lower in both non-encapsulated tretinoin (TTN) and TTN-LNC-treated groups. Nanoencapsulation allowed the use of smaller concentrations of tretinoin to supplement IVM medium thus reducing toxic effects related with its use, decreasing ROS levels and apoptose frequency, and improving the blastocyst rates. PMID:26476360

  8. Ice cores

    Svensson, Anders

    Ice cores from Antarctica, from Greenland, and from a number of smaller glaciers around the world yield a wealth of information on past climates and environments. Ice cores offer unique records on past temperatures, atmospheric composition (including greenhouse gases), volcanism, solar activity......, dustiness, and biomass burning, among others. In Antarctica, ice cores extend back more than 800,000 years before present (Jouzel et al. 2007), whereas. Greenland ice cores cover the last 130,000 years...

  9. Theoretical study of intramultiplet transitions in collisions of atoms in 3P electronic states with structureless targets: Ca(3P)+He

    The quantum close-coupling (CC) treatment of collisions of an atom in a 3P electronic state with a structureless target is developed, based on earlier work of Mies [Phys. Rev. A 7, 942 (1973)], and a j/sub z/-conserving [coupled-states (CS)] simplification presented. There is no direct coupling between the J = 0 and J = 1 levels; transitions between these levels will occur only as a result of Coriolis coupling involving the J = 2 state. Actual CC and CS calculations are reported for collisions of Ca 43P/sup o/ with He, based on the potential curves of Malvern [J. Phys. B 11, 831 (1978)]. In the CC results, of the three independent cross sections, J = 2→1 is predicted to be largest, and J = 2→0 smallest, over the entire range of collision energies sampled. By contrast, the CS approximation predicts the 1→0 transition to be forbidden, and yields only fair accuracy for the CC 2→1 and 2→0 transitions. The coupling between spin-orbit states is also interpreted within an adiabatic model. A comparison with the experimental results of Yuh and Dagdigian (preceding paper) is made by averaging the CC cross sections over the experimental translational energy distribution. The experimental cross sections for the 2→1 and 2→0 transitions are 3--4 times larger than the theoretical values, and the 2→0 cross section is found experimentally to be approx.3 times larger than the 1→0 cross section, in direct contrast with the theoretical prediction for this ratio

  10. Accurate long-range coefficients for two excited like isotope He atoms: He(2 1P)-He(2 1P), He(2 1P)-He(2 3P), and He(2 3P)-He(2 3P)

    A general formalism is used to express the long-range potential energies in inverse powers of the separation distance between two like atomic or molecular systems with P symmetries. The long-range molecular interaction coefficients are calculated for the molecular symmetries Δ, Π, and Σ, arising from the following interactions: He(2 1P)-He(2 1P), He(2 1P)-He(2 3P), and He(2 3P)-He(2 3P). The electric quadrupole-quadrupole term C5, the van der Waals (dispersion) term C6, and higher-order terms C8 and C10 are calculated ab initio using accurate variational wave functions in Hylleraas coordinates with finite nuclear mass effects. A comparison is made with previously published results where available