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Sample records for centre dot 2h2o

  1. Optical excitation in doped quasi-one-dimensional antiferromagnet (CsMnCl3 centre dot 2H2O+Cu2+)

    International Nuclear Information System (INIS)

    In the wide range of wavelengths and temperatures, the spectra of light absorption and luminescence excitation as well as the emission decay kinetics of a quasi-one-dimensional dielectric crystal CsMnCl3 centre dot 2H2O doped with copper ions (molar concentration 0-3%) are studied. The conclusion is made of the exchange of electronic excitation energy being possible between the matrix and dopant subsystems only in the lowest excited state due to migration of excitation and their trapping by excitation traps of the copper origin. From the analysis of the shape of decay kinetics curves of the matrix luminescence of the crystal, the values of hopping (along the chains of manganese ions) and trapping rates of magnetic excitons are determined

  2. Solution and single crystal spectroscopic characterization of (PPh4)(2)[Fe(CN)(5)(imidazole)]center dot 2H(2)O

    NARCIS (Netherlands)

    Tchouka, Heloise; Meetsma, Auke; Molnar, Gabor; Rechignat, Lionel; Browne, Wesley R.

    2011-01-01

    The compound (PPh4)(2)[Fe-III(CN)(5)(im)]center dot 2H(2)O (1) together with its C-13 labeled analogue have been synthesized (where im is imidazole) and characterized by UV/Vis, LD, IR, Raman and resonance Raman spectroscopy both in solution, powder and single crystalline form. The low spin state of

  3. Crystal structures of [Mn(bdc(Hspar2(H2O0.25]·2H2O containing MnO6+1 capped trigonal prisms and [Cu(Hspar2](bdc·2H2O containing CuO4 squares (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate

    Directory of Open Access Journals (Sweden)

    Zhe An

    2016-01-01

    Full Text Available The syntheses and crystal structures of 0.25-aqua(benzene-1,4-dicarboxylato-κ2O,O′bis(sparfloxacin-κ2O,O′manganese(II dihydrate, [Mn(C8H4O4(C19H22F2N4O32(H2O0.25]·2H2O or [Mn(bdc(Hspar2(H2O0.25]·2H2O, (I, and bis(sparfloxacin-κ2O,O′copper(II benzene-1,4-dicarboxylate dihydrate, [Cu(C19H22F2N4O32](C8H4O4·2H2O or [Cu(Hspar2](bdc·2H2O, (II, are reported (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate. The Mn2+ ion in (I is coordinated by two O,O′-bidentate Hspar neutral molecules (which exist as zwitterions and an O,O′-bidentate bdc dianion to generate a distorted MnO6 trigonal prism. A very long bond [2.580 (12 Å] from the Mn2+ ion to a 0.25-occupied water molecule projects through a square face of the prism. In (II, the Cu2+ ion lies on a crystallographic inversion centre and a CuO4 square-planar geometry arises from its coordination by two O,O′-bidentate Hspar molecules. The bdc dianion acts as a counter-ion to the cationic complex and does not bond to the metal ion. The Hspar ligands in both (I and (II feature intramolecular N—H...O hydrogen bonds, which close S(6 rings. In the crystals of both (I and (II, the components are linked by N—H...O, O—H...O and C—H...O hydrogen bonds, generating three-dimensional networks.

  4. Recent advances in the chemistry of SmI(2)-H(2)O.

    Science.gov (United States)

    Sautier, Brice; Procter, David J

    2012-01-01

    Recent work from our laboratories has shown SmI(2)-H(2)O to be a versatile, readily-accessible and non-toxic reductant that is more powerful than SmI(2). This review describes the reduction of functional groups that were previously thought to lie beyond the reach of SmI(2) and complexity-generating cyclisations and cyclisation cascades triggered by the reduction of the ester carbonyl group with SmI(2)-H(2)O.

  5. Thermodynamic analysis of metal dusting on iron in CO-H2-H2O atmosphere

    Institute of Scientific and Technical Information of China (English)

    Na Lei; Changyu Zhou; Guiming Hu; Cheng Chen

    2009-01-01

    This paper provides a calculation method for carbon activity in CO-H2-H2O atmosphere. The thermodynamic parameters (αC>)gas (carbon activity in environment) of different compositions at any temperature can be obtained by ΔGoT. A theoretical analysis has been conducted into the thermodynamic role of iron and the dependence of possible metal-dusting occurrence on temperature, gas composition and total pressure. In CO-H2-H2O gas mixtures, decreasing the molar fraction of H2O and increasing total pressure expands the temperature region for metal dusting. In CO-H2-H2O gas mixture of different compositions at any temperature and pressure for Fe, depending on relative values of (αC)gas, (αC)Fe3C/Fe and αC=1, three zones were found to exist.

  6. Preparation, configurational and DFT-NBO analysis of nickel(II) complexes with edta-type ligands containing six-membered backbone ring : crystal structure of [Ni(H2O)(6)][Ni(1,3-pdta)]center dot 2H(2)O

    NARCIS (Netherlands)

    Belosevic, Svetlana; Vasojevic, Miorad M.; Jeremic, Marija S.; Meetsma, Auke; Matovic, Zoran D.

    2013-01-01

    New hexadentate nickel(II) complex Mg[Ni(1,3-pd3ap)]center dot 10H(2)O containing unsymmetrical edta-type ligand, 1,3-propanediamine-N,N,N '-triacetate-N-3-propionate (1,3-pd3ap), has been prepared, chromatographically separated, and characterized. Only one [trans(O-5)] of the two possible geometric

  7. Synthesis and Crystal Structure of a Cyano-bridged Bimetallic Complex [La(betaine)2(H2O)6Fe(CN)6]·2H2O

    Institute of Scientific and Technical Information of China (English)

    LIANG Shu-Hui; CHE Yun-Xia; ZHENG Ji-Min

    2005-01-01

    The title complex [La(betaine)2(H2O)6Fe(CN)6](2H2O (betaine = (CH3)3NCH2CO2) has been synthesized and characterized by X-ray single-crystal structure analysis. The crystal crystallizes in monoclinic, space group P21/n with a = 15.793(5), b = 8.927(3), c = 22.257(7) (A), β = 110.147(5)°, C16H38FeLaN8O12, Mr = 729.31, Z = 4, V = 2946.0(15) (A)3, Dc = 1.640 g/m3, μ(MoKα) = 1.988 mm-1, F(000) =1476, R = 0.0388 and wR = 0.0827 for 4237 observed reflections (I > 2σ(I)). The La3+ ion is nine-coordinated by one cyano nitrogen atom and eight oxygen atoms of two betaine and six water molecules. Each complex molecule is connected to form a 3D network structure by some O-H…O and O-H…N hydrogen bonds.

  8. Structural transition study of NiCl2.2H2O by specific heat

    International Nuclear Information System (INIS)

    The specific heat of polycrystalline NiCl2.2H2O measured in an adiabatic calorimeter by the heat-pulse method between 80 and 281 K indicates a first-order phase transition at Tc = (220.0 ± 0.5) K. This confirms a crystallographic transformation first detected by X-ray and EPR methods. (author)

  9. Study of UO2F2 - H2O - HF compounds

    International Nuclear Information System (INIS)

    We study various compounds resulting from the interaction of UO2F2 with H2O and HF (gas), and various triple compounds UO2F2 - H2O - HF; the conditions of decomposition and the thermodynamic limits of stability are specified. (author)

  10. Relaxation phenomena in CsCoCl3·2 H2O

    NARCIS (Netherlands)

    Flokstra, J.; Gerritsma, G.J.; Vermeulen, A.J.W.A; Botterman, A.C.

    1973-01-01

    Dynamic susceptibility measurements have been performed on a single crystal of CsCoCl3·2H2O at liquid temperatures by means of a Hartshorn mutual inductance bridge. At the magnetic phase transition a maximum in τabs(H) has been observed. A jump in τabs(T) has been found at the λ-point of liquid heli

  11. Preparation and Molecular Structure of (SCZ)(TNPG)·2H2O

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-Yan; ZHANG Tong-Lai; ZHANG Jian-Guo

    2005-01-01

    The (SCZ)(TNPG)·2H2O prepared by mixing semicarbazide (SCZ) and trinitrophloroglucinol (TNPG) was characterized by elemental analysis and IR measurement, and its crystal structure was determined by X-ray single-crystal diffraction analysis.The crystal belongs to triclinic,0.93966(19), c = 1.1925(2) nm, α = 67.48(3), β = 77.56(3), γ = 78.93(3)°, V = 0.6908(2) nm3, Z = 2,Dc = 1.789 g/cm3, Mr = 373.23, F(000) = 384, S = 0.999 andt(MoKα) = 0.172 mm-1.The final R and wR are 0.0394 and 0.1057 for 1724 observed reflections with I > 2σ(I).It is concluded that (SCZ)(TNPG) 2H2O is an ionic compound composed of a cation SCZ+, an anion TNPG- and two water molecules.The TNPG anion and SCZ+ cation are bonded together by electrostatic attraction and hydrogen bonds, and the compound structure is stable.The thermal decomposition of (SCZ)(TNPG) 2H2O was studied by using TG-DTG and DSC techniques with a heating rate of 10 ℃/min, showing the compound contains one endothermic process of dehydrating stage and two intensive exothermic decomposition stages.The enthalpy of exothermic decomposition reaction is 452.31 kJ/mol.

  12. High purity H-2/H2O/Ni/SZ electrodes at 500 degrees C

    DEFF Research Database (Denmark)

    Høgh, Jens Valdemar Thorvald; Hansen, Karin Vels; Norrman, Kion;

    2013-01-01

    The performance of SOFC (solid oxide fuel cell) anodes is influenced negatively by impurities. In the present study segregation of impurities is minimized by using high purity materials at relatively low temperatures to prevent fast segregation. Ni point electrodes on polished single crystals...... of stabilized zirconia (SZ) with 10,13 and 18 mol% yttria and one with 6 mol% scandia plus 4 mol% yttria were studied at open circuit voltage at 400-500 degrees C in mixtures of H-2/H2O over 46 days. The polarization resistances (R-p) for all samples increased significantly during the first 10-20 days at 500...

  13. Redetermination of [EuCl2(H2O6]Cl

    Directory of Open Access Journals (Sweden)

    Frank Tambornino

    2014-06-01

    Full Text Available The crystal structure of the title compound, hexaaquadichloridoeuropium(III chloride, was redetermined with modern crystallographic methods. In comparison with the previous study [Lepert et al. (1983. Aust. J. Chem. 36, 477–482], it could be shown that the atomic coordinates of some O atoms had been confused and now were corrected. Moreover, it was possible to freely refine the positions of the H atoms and thus to improve the accurracy of the crystal structure. [EuCl2(H2O6]Cl crystallizes with the GdCl3·6H2O structure-type, exhibiting discrete [EuCl2(H2O6]+ cations as the main building blocks. The main blocks are linked with isolated chloride anions via O—H...Cl hydrogen bonds into a three-dimensional framework. The Eu3+ cation is located on a twofold rotation axis and is coordinated in the form of a Cl2O6 square antiprism. One chloride anion coordinates directly to Eu3+, whereas the other chloride anion, situated on a twofold rotation axis, is hydrogen bonded to six octahedrally arranged water molecules.

  14. Volumetric Properties and Fluid Phase Equilibria of CO2 + H2O

    Energy Technology Data Exchange (ETDEWEB)

    Capobianco, Ryan [Virginia Polytechnic Institute and State University; Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Wesolowski, David J [ORNL; Cole, David R [ORNL; Bodnar, Robert [Virginia Polytechnic Institute and State University

    2013-01-01

    The need for accurate modeling of fluid-mineral processes over wide ranges of temperature, pressure and composition highlighted considerable uncertainties of available property data and equations of state, even for the CO2 + H2O binary system. In particular, the solubility, activity, and ionic dissociation equilibrium data for the CO2-rich phase, which are essential for understanding dissolution/precipitation, fluid-matrix reactions, and solute transport, are uncertain or missing. In this paper we report the results of a new experimental study of volumetric and phase equilibrium properties of CO2 + H2O, to be followed by measurements for bulk and confined multicomponent fluid mixtures. Mixture densities were measured by vibrating tube densimetry (VTD) over the entire composition range at T = 200 and 250 C and P = 20, 40, 60, and 80 MPa. Initial analysis of the mutual solubilities, determined from volumetric data, shows good agreement with earlier results for the aqueous phase, but finds that the data of Takenouchi and Kennedy (1964) significantly overestimated the solubility of water in supercritical CO2 (by a factor of more than two at 200 C). Resolving this well-known discrepancy will have a direct impact on the accuracy of predictive modeling of CO2 injection in geothermal reservoirs and geological carbon sequestration through improved equations of state, needed for calibration of predictive molecular-scale models and large-scale reactive transport simulations.

  15. Modeling Ice Giant Interiors Using Constraints on the H2-H2O Critical Curve

    Science.gov (United States)

    Bailey, E.; Stevenson, D. J.

    2015-12-01

    We present a range of models of Uranus and Neptune, taking into account recent experimental data (Bali, 2013) implying the location of the critical curve of the H2-H2O system at pressures up to 2.6 GPa. The models presented satisfy the observed total mass of each planet and the radius at the observed 1-bar pressure level. We assume the existence of three regions at different depths: an outer adiabatic envelope composed predominately of H2 and He, with a helium mass fraction 0.26, a water-rich layer including varied amounts of rock and hydrogen, and a chemically homogeneous rock core. Using measured rotation rates of Uranus and Neptune, and a density profile obtained for each model using constituent equations of state and the assumption of hydrostatic equilibrium, we calculate the gravitational harmonics J2 and J4 for comparison with observed values as an additional constraint. The H2-H2O critical curve provides information about the nature of the boundary between the outer, hydrogen-rich envelope and underlying water-rich layer. The extrapolated critical curve for hydrogen-water mixtures crosses the adiabat of the outer atmospheric shell in these models at two depths, implying a shallow outer region of limited miscibility, an intermediate region between ~90 and 98 percent of the total planet radius within which hydrogen and water can mix in all proportions, and another, deeper region of limited miscibility at less than ~90 percent of the total planet radius. The pressure and temperature of the gaseous adiabatic shell at the depth of the shallowest extent of the water-rich layer determines whether a gradual compositional transition or an ocean surface boundary may exist at depth in these planets. To satisfy the observed J2, the outer extent of the water-rich layer in these models must be located between approximately 80 and 85 percent of the total planet radius, within the deep region of limited H2-H2O miscibility, implying an ocean surface is possible within the

  16. Crystal structure of erbium trichloroacetate Er(CCl3COO)·2H2O

    International Nuclear Information System (INIS)

    X-ray structure study of Er(CCl3COO)3x2H2O crystals is conducted (SYNTEX P21 autodiffractometer, MoKα-radiation). The crystals are of triclinic syngony: a11.697 (4), b=12.790 (4), c=15223 (4) A, α=70.67 (3), β=77.80 (3), γ=6561 (3)deg; space group P1, Z=4. There are two crystallographically independent types of erbium atoms with coordination numbers 7 and 8, respectively, in the unit cell. These atoms are linked by tetra- and double-carboxylated cross-links in the endless chains, while water molecules complete the metal coordination polyhedron is within 2.259-2.393 A interval, while in seven-coordination - within 2.229-2.267 A interval. Er-H2O distances constitute 2.389-2.534 A

  17. Equilibrium of hydroxyl complex ions in Pb2+-H2O system

    Institute of Scientific and Technical Information of China (English)

    WANG Yun-yan; CHAI Li-yuan; CHANG Hao; PENG Xiao-yu; SHU Yu-de

    2009-01-01

    The thermodynamics equilibrium principle was used to construct the diagrams for the concentration of complex ions (pc) vs pH, the distribution ratio of lead hydroxyl complex ions (αn) vs pH, and the conditional solubility product of Pb(OH)2 vs pH in the Pb2+-H2O system. The relationship between the equilibrium concentration of each kind of lead hydroxyl complex ions in equilibrium with Pb(OH)2(s) and pH value was shown in the system. The minimum solubility of lead is at the pH value of 10.096-10.997. The distribution ratio of each kind of the lead hydroxyl complex ions is determined as a function of the pH value and the total lead concentration ([Pb]T). The diagram for the conditional solubility product, pKSP vs pH, shows that each kind of lead hydroxyl complex ions existing in the system is dependent upon an optimized pH value at the established concentration of [Pb]T, and that pKSP reaches the minimum at the pH value of 10.3-11.2. The results can provide a theoretical basis for removing lead ions from wastewater by the neutralization and hydrolyzation technology.

  18. The H2O2-H2O Hypothesis: Extremophiles Adapted to Conditions on Mars?

    Science.gov (United States)

    Houtkooper, Joop M.; Schulze-Makuch, Dirk

    2007-08-01

    The discovery of extremophiles on Earth is a sequence of discoveries of life in environments where it had been deemed impossible a few decades ago. The next frontier may be the Martian surface environment: could life have adapted to this harsh environment? What we learned from terrestrial extremophiles is that life adapts to every available niche where energy, liquid water and organic materials are available so that in principle metabolism and propagation are possible. A feasible adaptation mechanism to the Martian surface environment would be the incorporation of a high concentration of hydrogen peroxide in the intracellular fluid of organisms. The H2O2-H2O hypothesis suggests the existence of Martian organisms that have a mixture of H2O2 and H2O instead of salty water as their intracellular liquid (Houtkooper and Schulze-Makuch, 2007). The advantages are that the freezing point is low (the eutectic freezes at 56.5°C) and that the mixture is hygroscopic. This would enable the organisms to scavenge water from the atmosphere or from the adsorbed layers of water molecules on mineral grains, with H2O2 being also a source of oxygen. Moreover, below its freezing point the H2O2-H2O mixture has the tendency to supercool. Hydrogen peroxide is not unknown to biochemistry on Earth. There are organisms for which H2O2 plays a significant role: the bombardier beetle, Brachinus crepitans, produces a 25% H2O2 solution and, when attacked by a predator, mixes it with a fluid containing hydroquinone and a catalyst, which produces an audible steam explosion and noxious fumes. Another example is Acetobacter peroxidans, which uses H2O2 in its metabolism. H2O2 plays various other roles, such as the mediation of physiological responses such as cell proliferation, differentiation, and migration. Moreover, most eukaryotic cells contain an organelle, the peroxisome, which mediates the reactions involving H2O2. Therefore it is feasible that in the course of evolution, water-based organisms

  19. Nonisothermal Kinetice of Dehydration Process of [Sm(m-CIBA)3phen]2·2H2O and[Sm(p-CIBA)3phen]2·2H2O

    Institute of Scientific and Technical Information of China (English)

    REN Ning; WANG Xie; ZHANG Jie; ZHANG Jian-jun; XU Su-ling; ZHANG Hai-yan

    2008-01-01

    Compounds[Sm(m-CIBA)3phen]2·2H2O and[Sm(p-ClBA)3phen]2·2H2O(m-ClBA=m-chlorobenzoate,PClBA=p-chlorobenzoate,phen=1,10-phenanthroline)were prepared.The dehydration processes and kinetics of these compounds were studied from the analysis of the DSC curves using a method of processing the data of thermal analysis kinetics.The Arrhenius equation for the dehydration process can be expressed as lnk=38.65-243.90x103|RT for and△S≠ of dehydration reaction for the title compounds are determined,respectively.

  20. Radiation heterogeneous processes in the system nano-ZrO2+H2O

    International Nuclear Information System (INIS)

    Full text : In this paper, in order to determine the influence of zirconia on the radiolysis of water there were investigated the kinetics of accumulation of molecular hydrogen at the radiolytic decomposition of water in the system ZrO2 + H2O at T = 300 K. On the basis of the kinetic curves there was determined value of the process rate and radiation - chemical yield of molecular hydrogen G(H2) calculated for the energy of the absorbed water. In the operation of nuclear reactors construction materials (ZrO2) are simultaneously exposed to the influence of temperature and radiation in contact with the coolant. In this paper, in order to identify regularities of radiation, radiation-thermal processes in contact of coolant with the nanopowder of ZrO2, which is the material of nuclear reactors with water cooling there were studied the kinetics of accumulation of molecular hydrogen under the influence of gamma - radiation at different temperatures. Zirconium dioxide (ZrO2) is one of the materials, which are widely used in science and technology. ZrO2 is used in the manufacture of nuclear reactor fuel cells that convert chemical energy into electrical energy. Fuel cell devices operating at high temperatures. The use of zirconia for fuel cells due to the high ionic conductivity, which is due to the transfer of the oxygen anion vacancies. In order to ensure their high quality there are use nanoscale powders. Nanoscale systems are very different from conventional single-crystal systems. Therefore, the study of their properties under the influence of gamma - radiation is of practical and scientific interest

  1. Adsorbed Layers of D2, H2, O2, and 3He on Graphite Studied by Neutron Scattering

    DEFF Research Database (Denmark)

    Nielsen, Mourits; McTague, J. P.; Ellenson, W. D.

    1977-01-01

    The phase diagrams of adsorbed monolayers of D2, H2, O2, and 3He on graphite have been measured by neutron diffraction. H2 and D2-layers have a registered √3 structure at low coverages, and at monolayer completion they have a dense triangular structure, which is incommensurate with the substrate...

  2. ACIDIFICATION OF RAIN IN THE PRESENCE OF SO2, H2O2, O3, AND HNO3

    Science.gov (United States)

    The production of acid sulfate and the accumulation of acid nitrate are calculated for falling raindrops using a physico-chemical model that accounts for the mass transfer of SO2, H2O2, O3, HNO3, and CO2. The acidification is postulated to occur through the absorption of free gas...

  3. Magnetic Properties of a Three-dimensional Supramolecular Complex[Co(hmt)2(SCN)2(H2O)2][Co(SCN)2(H2O)4](H2O)2%三维超分子配合物[Co(hmt)2(SCN)2(H2O)2][Co(SCN)2(H2O)4](H2O)2的磁性质(英文)

    Institute of Scientific and Technical Information of China (English)

    李纲; 李金鹏; 王翠红; 李林科; 侯红卫

    2002-01-01

    Supramolecular complex [Co(hmt)2(SCN)2(H2O)2][Co(SCN)2(H2O)4](H2O)2 (hmt =hexamethylenetetramine) is prepared according to previous literature. The determination of variable-temperature magnetic susceptibilities (5~300 K) shows that the magnetic behavior obeys the Curie-Weiss law over the whole temperature range. In this compound weak antiferromagnetic coupling can be observed.%参照文献制备了三维超分子配合物[Co(hmt)2(SCN)2(H2O)2][Co(SCN)2(H2O)4](H2O)2, 测试了该化合物在5~300 K范围内的变温磁化率.结果表明,其磁行为在测定的温度范围内遵守Curie-Weiss定律, 金属离子之间存在弱的反铁磁偶合.

  4. Modeling the binary system Mn(NO3)2-H2O with the extended universal quasichemical (UNIQUAC) model

    DEFF Research Database (Denmark)

    Arrad, Mouad; Kaddami, Mohammed; Maous, Jaafar;

    2015-01-01

    in aqueous solutions.Thermodynamic modeling for the binary system of Mn(NO3)2-H2O is also presented based on this new experimental solubility data and some modification on the available data bank.Model parameters for this system were determined and revisited; these parameters are generally valid...

  5. Synthesis and the crystal and molecular structure of the silver(I)-germanium(IV) polymeric complex with citrate anions {[Ag2Ge(H Cit)2(H2O)2] • 2H2O} n

    Science.gov (United States)

    Sergienko, V. S.; Martsinko, E. E.; Seifullina, I. I.; Churakov, A. V.; Chebanenko, E. A.

    2016-03-01

    The synthesis and X-ray diffraction study of compound {[Ag2Ge(H Cit)2(H2O)2] • 2H2O} n , where H4 Cit is the citric acid, are performed. In the polymeric structure, the H Cit 3- ligand fulfils the tetradentate chelate-μ4-bridging (3Ag, Ge) function (tridentate with respect to Ge and Ag atoms). The Ge atom is octahedrally coordinated by six O atoms of two H Cit 3-ligands. The coordination polyhedron of the Ag atom is an irregular five-vertex polyhedron [four O atoms of four H Cit 3- ligands and the O(H2O) atom]. An extended system of O-H···O hydrogen bonds connects complex molecules into a supramolecular 3D-framework.

  6. Production of 34S-labeled gypsum (Ca34SO4.2H2O Produção de gesso (Ca34SO4.2H2O, marcado com 34S

    Directory of Open Access Journals (Sweden)

    Alexssandra Luiza Rodrigues Molina Rossete

    2006-08-01

    Full Text Available Agricultural gypsum (CaSO4.2H2O stands out as an effective source of calcium and sulfur, and to control aluminum saturation in the soil. Labeled as 34S it can elucidate important aspects of the sulfur cycle. Ca34SO4.2H2O was obtained by chemical reaction between Ca(OH2 and H2(34SO4, performed under slow agitation. The acid was produced by ion exchange chromatography using the Dowex 50WX8 cation exchange resin and a Na2(34SO4 eluting solution. After precipitation, the precipitate was separated and dried in a ventilated oven at 60ºC. From 2.2 L H2SO4 0.2 mol L-1 and 33.6 g Ca(OH2, 73.7 ± 0.6 g Ca34SO4.2H2O were produced on average in the tests, representing a mean yield of 94.6 ± 0.8%, with 98% purity. The 34SO2 gas was obtained from Ca34SO4.2H2O in the presence of NaPO3 in a high vacuum line and was used for the isotopic determination of S in an ATLAS-MAT model CH-4 mass spectrometer.O gesso agrícola (CaSO4.2H2O destaca-se como fonte eficiente de cálcio e enxofre e na redução da saturação de alumínio no solo. O 34S como traçador isotópico pode elucidar aspectos importantes no ciclo do enxofre. Para tanto o Ca34SO4.2H2O foi obtido por reação química entre o Ca(OH2 e solução de H2(34SO4, realizada sob agitação lenta. O ácido foi produzido por cromatografia de troca iônica, utilizando resina catiônica Dowex 50WX8 e solução eluente de Na2(34SO4. Após a precipitação foi separado o precipitado e realizada a secagem em estufa ventilada à temperatura de 60ºC. Nos testes, a partir de 2,2 L de H2SO4 0,2 mol L-1 e 33,6 g de Ca(OH2, foram produzidos em média 73,7 ± 0,6 g de Ca34SO4.2H2O representando um rendimento médio de 94,6 ± 0,8%, com pureza de 98%. A partir do Ca34SO4.2H2O na presença de NaPO3, em linha de alto vácuo, obteve-se o gás 34SO2 utilizado para a determinação isotópica do S no espectrômetro de massas ATLAS-MAT modelo CH-4.

  7. The solubilities of calcite, aragonite and vaterite in CO2-H2O solutions between 0 and 90°C, and an evaluation of the aqueous model for the system CaCO3-CO2-H2O

    Science.gov (United States)

    Plummer, L. Niel; Busenberg, Eurybiades

    1982-01-01

    Calculations based on approximately 350 new measurements (CaT-PCO2) of the solubilities of calcite, aragonite and vaterite in CO2-H2O solutions between 0 and 90°C indicate the following values for the log of the equilibrium constants KC, KA, and KV respectively, for the reaction CaCO3(s) = Ca2+ + CO2−3: 

  8. Hydrothermal Synthesis and Structure of a Mixed-valence Polyoxotungstate Decorated by Copper(I) Coordination Group, [Cu(en)2H2O]2[{Cu(en)2}HPW12O40]·2H2O

    Institute of Scientific and Technical Information of China (English)

    LI Zhen; LIN Bi-Zhou; HAN Guo-Hua; GENG Feng; LIU Pei-De

    2005-01-01

    A complex [Cu(en)2H2O]2[{Cu(en)2}HPW12O40]·2H2O (C12H57Cu3N12O44PW12, Mr = 3501.49) has been synthesized under hydrothermal conditions and its crystal structure was determined by X-ray diffraction.It crystallizes in the orthorhombic system, space group Pbca with a = 21.680(4), b = 20.680(4), c = 26.120(5) (A), V = 11711(4) (A)3, Dc = 3.972 g/cm3, Z = 8, μ(MoKa) = 24.661 mm-1, F(000) = 12440, the final R = 0.0527 and wR = 0.1416 for 11527 observed reflec- tions with I > 2σ(I).The crystal structure is composed of [{Cu(en)2}HPW12O40]2- anions, discrete [Cu(en)2H2O]+ complex cations and crystal water molecules, which are held together into a three- dimensional network through hydrogen-bonding interactions.The anionic [{Cu(en)2}HPW12O40]2- is formed by the mixed valance {HPWVI11WVO40}3- Keggin unit covalently linked by a {Cu(en)2}+ group.

  9. Electrochemical investigation of nickel pattern electrodes in H2/H2O and CO/CO2 atmospheres

    DEFF Research Database (Denmark)

    Ehn, A.; Høgh, Jens Valdemar Thorvald; Graczyk, M.;

    2010-01-01

    In this study, nickel pattern electrodes were electrochemically investigated in a three-electrode setup, operating both with H2 / H2 O and CO/ CO2 atmospheres. Heating introduced structural differences in the nickel layer among the pattern electrodes, which appear to affect the electrode performa......In this study, nickel pattern electrodes were electrochemically investigated in a three-electrode setup, operating both with H2 / H2 O and CO/ CO2 atmospheres. Heating introduced structural differences in the nickel layer among the pattern electrodes, which appear to affect the electrode...... and the partial pressure of CO was determined for the dense nickel pattern electrode, which agrees with previous results using nickel point electrodes. © 2010 The Electrochemical Society....

  10. Chemical synthesis and characterization of hydrous tin oxide (SnO2:H2O) thin films

    Indian Academy of Sciences (India)

    S N Pusawale; P R Deshmukh; C D Lokhande

    2011-10-01

    In the present investigation, we report chemical synthesis of hydrous tin oxide (SnO2:H2O) thin films by successive ionic layer adsorption and reaction (SILAR) method at room temperature (∼300 K). The films are characterized for their structural and surface morphological properties. The formation of nanocrystalline SnO2 with porous and agglomerated particle morphology is revealed from X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies, respectively. The Fourier transform infrared spectroscopy (FTIR) study confirmed the formation of Sn–O phase and hydrous nature of the deposited film. Static water contact angle studies showed the hydrophilic nature of SnO2:H2O thin film. Electrical resistivity showed the semiconducting behaviour with room temperature electrical resistivity of 105 cm. The electrochemical properties studied in 0.5 M Na2SO4 electrolyte showed a specific capacitance of 25 F g-1 at 5 mVs-1 scan rate.

  11. Hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) into gypsum (CaSO 4·2H 2O). The influence of the sodium poly(acrylate)/surface interaction and molecular weight

    Science.gov (United States)

    Boisvert, Jean-Philippe; Domenech, Marc; Foissy, Alain; Persello, Jacques; Mutin, Jean-Claude

    2000-12-01

    The retarding influence of sodium poly(acrylate) (PANa) on the hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) was investigated. This study reports the influence of sodium poly(acrylate) on hemihydrate dissolution, on homogenous and heterogeneous gypsum (CaSO 4·2H 2O) nucleation as well as on gypsum growth. It is shown that adsorption of PANa does not hinder the dissolution of hemihydrate in the present experimental conditions. The specific interaction of PANa with gypsum can explain the oriented growth of gypsum crystal. The gypsum growth is slowed down but cannot be blocked by the adsorption of PANa. On the other hand, PANa can block the heterogeneous and homogenous gypsum nucleation. As soon as a critical surface density of PANa onto the hemihydrate surface is reached, the heterogeneous gypsum nucleation is prevented and hemihydrate hydration is indefinitely blocked. The interaction between PANa and the hemihydrate surface is of prime importance to control hydration. Also, the influence of the molecular weight of PANa on homogenous nucleation has been investigated. The precipitation of calcium polyacrylate can explain the differences between the two molecular weights used (2100 and 20 000). This work leads to the conclusion that heterogeneous nucleation is the key process that controls hydration of a system in which hemihydrate dissolution, gypsum nucleation and growth are all occurring at the same time in a continuous manner.

  12. Physical characterization and reactivity of the uranyl peroxide [UO2(η(2)-O2)(H2O)2]·2H2O: implications for storage of spent nuclear fuels.

    Science.gov (United States)

    Mallon, Colm; Walshe, Aurora; Forster, Robert J; Keyes, Tia E; Baker, Robert J

    2012-08-01

    The unusual uranyl peroxide studtite, [UO(2)(η(2)-O(2))(H(2)O)(2)]·2H(2)O, is a phase alteration product of spent nuclear fuel and has been characterized by solid-state cyclic voltammetry. The voltammogram exhibits two reduction waves that have been assigned to the U(VI/V) redox couple at -0.74 V and to the U(V/IV) redox couple at -1.10 V. This potential shows some dependence upon the identity of the cation of the supporting electrolyte, where cations with larger ionic radii exhibit more cathodic reduction potentials. Raman spectroelectrochemistry indicated that exhaustive reduction at either potential result in a product that does not contain peroxide linkers and is likely to be UO(2). On the basis of the reduction potentials, the unusual behavior of neptunium in the presence of studtite can be rationalized. Furthermore, the oxidation of other species relevant to the long-term storage of nuclear fuel, namely, iodine and iodide, has been explored. The phase altered product should therefore be considered as electrochemically noninnocent. Radiotracer studies with (241)Am show that it does not interact with studtite so mobility will not be retarded in repositories. Finally, a large difference in band gap energies between studtite and its dehydrated congener metastudtite has been determined from the electronic absorption spectra. PMID:22813353

  13. Study of T-H isotope exchange between H2-H2O by Pt-C-PTFE hydrophobic catalyst

    International Nuclear Information System (INIS)

    The preparation of Pt-C-PTFE hydrophobic catalyst is described. The experiments of T-H isotope exchange between H2/H2O by Pt-C-PTFE hydrophobic catalyst were carried out at 30 deg C, 50 deg C and 75 deg C respectively. Within the limits (9.65-38.22) cm/s, catalystic activity increases with the increase of hydrogen flow rate. The catalystic activity at 50 deg C is optimum. The catalystic activity of this catalyst between gas-liquid is larger than that between gas-vapour. Mixture of the hydrophobic catalyst with hydrophilic filler in the bed can improve hydrogen isotope exchange

  14. Synthesis and Crystal Structure of a New Potassium Yttrium Diphosphate Dihydrate KYP2O7·2H2O

    Institute of Scientific and Technical Information of China (English)

    Férid M. Horchani-Naifer K

    2008-01-01

    The dihydrated potassium yttrium diphosphate, KYP2O7·2H2O, has been synthe-sized for the first time. Single-crystal XRD study has allowed the determination of its structure and correct formula. It crystallizes in the monoclinic system, space group P21/c, with the cell parameters a = 7.7069(3), b = 10.5801(4), c = 10.0204(5) ?, β = 93.24(3)°, V = 815.76(6) ?3, Z = 4, Mr = 337.98, F(000) = 656, Dc = 2.752 g/cm3 and μ = 8.073 mm-1. The single-crystal structure was solved from 1856 unique reflections with the final R = 0.0365 and wR = 0.0772, refined with 119 parameters. The atomic arrangement of KYP2O7·2H2O is built by the P2O7 groups, the YO7 and the KO10 polyhedrons which are connected by corner and edge-sharing to form a three-dimensional framework. Water molecules are directly bonded to the Y and K atoms, and they are located in channels running along the a direction.

  15. Degradation of Pentachlorophenol in Aqueous Solution by the UV/ZrO 2 /H 2 O 2 Photocatalytic Process

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Samarghandi

    2015-12-01

    Full Text Available Pentachlorophenol (PCP, which is one of the resistant phenolic compounds, has been classified in the category of EPA’s priority pollutants due to its high toxicity and carcinogenic potential. Therefore, its removal from water and wastewater is very important. Various methods have been studied for removing the compound, among which advanced oxidation processes (AOPs have attracted much attention because of ease of application and high efficiency. Thus the aim of this study was to investigate the efficiency of the UV/ZrO2/H2O2 process, as an AOP, for PCP removal from aquatic environments. The effects of several parameters such as ultraviolet (UV exposure time, initial PCP concentration, pH, concentration of zirconium dioxide (ZrO2 nanoparticles, and H2O2 concentration were studied. Kinetics of the reaction was also detected. The concentration of the stated materials in the samples was determined using a spectrophotometer at 500 nm. The results showed that the highest efficiency (approximately 100% was reached at optimized conditions of pH 6, contact time of 30 minutes, initial PCP concentration of 20 mg/L, the nanoparticles concentration of 0.1 g/L and H2O2 concentration of 14.7 mM/L. Also, the process followed the first order kinetics reaction. The obtained results illustrated that the UV/ZrO2/H2O2 process has a high ability in removing PCP.

  16. CO2-H2O和CO2-H2O-NaCl体系的相平衡研究进展%Progress in the Study on the Phase Equilibria of the CO2-H2O and CO2-H2O-NaCl Systems

    Institute of Scientific and Technical Information of China (English)

    吉远辉; 吉晓燕; 冯新; 刘畅; 吕玲红; 陆小华

    2007-01-01

    To study the feasibility of CO2 geological sequestration, it is needed to understand the complicated multiple-phase equilibrium and the densities of aqueous solution with CO2 and multi-ions under wide geological conditions (273.15 473.15K, 0-60MPa), which are also essential for designing separation equipments in chemical or oil-related industries.For this purpose, studies on the relevant phase equilibria and densities are reviewed and analyzed and the method to improve or modify the existing model is suggested in order to obtain more reliable predictions in a wide temperature and pressure range.Besides, three different models (the electrolyte non random twoliquid (ELECNRTL), the electrolyte NRTL combining with Helgeson model (ENRTL-HG), Pitzer activity coefficient model combining with Helgeson model (PITZ-HG) are used to calculate the vapor-liquid phase equilibrium of CO2-H2O and CO2-H2O-NaCl systems.For CO2-H2O system, the calculation results agree with the experimental data very well at low and medium pressure (0-20MPa), but there are great discrepancies above 20MPa.For the water content at 473.15K, the calculated results agree with the experimental data quite well.For the CO2-H2O-NaCl system, the PITZ-HG model show better results than ELECNRTL and ENRTL-HG models at the NaCI concentration of 0.52mol·L-1.Bur for the NaCl concentration of 3.997mol·L-1,using the ELECNRTL and ENRTL-HG models gives better results than using the PITZ-HG model.It is shown that available experimental data and the thermodynamic calculations can satisfy the needs of the calculation of the sequestration capacity in the temperature and pressure range for disposal of CO2 in deep saline aquifers.More experimental data and more accurate thermodynamic calculations are needed in high temperature and pressure ranges (above 398.15K and 31.5MPa).

  17. Understanding the Factors That Control the Formation and Morphology of Zn5(OH8(NO32·2H2O through Hydrothermal Route

    Directory of Open Access Journals (Sweden)

    Xu Liu

    2013-01-01

    Full Text Available The influence of the choice of ethanol-water volume ratio, concentration of zinc salt, and ZnO buffer layer on the formation and morphology of Zn5(OH8(NO32·2H2O grown from the hydrothermal route was systematically discussed. Experimental results suggested that Zn5(OH8(NO32·2H2O rectangle sheets and Zn5(OH8(NO32·2H2O upright-standing plates were obtained by limiting ethanol-water volume ratio. The concentration of zinc salt was crucial for getting phase-pure Zn5(OH8(NO32·2H2O. The presence of ZnO buffer layer could lead to the that chemical composition of product grown on the substrate was totally different from the product grown in the solution. Possible formation mechanism of Zn5(OH8(NO32·2H2O was also studied. Raman spectrum of Zn5(OH8(NO32·2H2O displays a complex behavior with four modes, which can be assigned to the vibrational modes of Zn–H–O, Zn–O, H2O-nitrate, and nitrate. Porously ZnO rectangle sheets were obtained by thermal treatment of Zn5(OH8(NO32·2H2O rectangle sheets.

  18. Determination of muscle protein synthesis rates in fish using (2)H2O and (2)H NMR analysis of alanine.

    Science.gov (United States)

    Marques, Cátia; Viegas, Filipa; Rito, João; Jones, John; Viegas, Ivan

    2016-09-15

    Following administration of deuterated water ((2)H2O), the fractional synthetic rate (FSR) of a given endogenous protein can be estimated by (2)H-enrichment quantification of its alanine residues. Currently, this is measured by mass spectrometry following a derivatization procedure. Muscle FSR was measured by (1)H/(2)H NMR analysis of alanine from seabass kept for 6 days in 5% (2)H-enriched saltwater, following acid hydrolysis and amino acid isolation by cation-exchange chromatography of muscle tissue. The analysis is simple and robust, and provides precise measurements of excess alanine (2)H-enrichment in the 0.1-0.4% range from 50 mmol of alanine recovered from muscle protein. PMID:27418547

  19. Synthesis and Crystal Structure of [{Cd(hmbdc)(H2O)3}·2H2O]n

    Institute of Scientific and Technical Information of China (English)

    HU Yue-Hua; WANG Yan; WANG Zuo-Wei; LI Yi-Zhi; ZHENG He-Gen

    2007-01-01

    A novel coordination polymer [{Cd(hmbdc)(H2O)3}·2H2O]n (hmbdc=5-hydroxy- isophthalic acid) has been synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a=9.599(3), b=18.699(5), c=7.557(2) (A), β= 108.198(4)°, V=1288.6(6) (A)3, Z=4, Mr=382.60, Dc=1.972 g/cm3, F(000)=760, μ=1.740, the final R=0.0555 and wR=0.0995 for 1732 observed reflections with Ⅰ > 2σ(Ⅰ). The structural analysis shows that the intermolecular hydrogen bonds and π-π interactions result in a three-dimensional supramolecular framework.

  20. Synthesis and Structural Characterization of [Co(Q)2(H2O)2](Q=8-Hydroxyquinoline Ion)

    Institute of Scientific and Technical Information of China (English)

    HU Chang-wen; WANG Chun-xiu; LI Hui; NIU Xue-li; PAN Wan-long; GONG Yun

    2006-01-01

    The single crystal of bi (8-hydroxyquinoline) bihydrated cobalt ( Ⅱ ) complex, [ Co ( Q)2 ( H2O)2 ] (Q = 8-hydroxyquinoline ion), has been synthesized by general method and structurally characterized by single crystal X-ray diffraction. Crystal data: C18H16CoN2O4, monoclinic, C2/c, a = 1.336 2(4) nm, b = 0.941 2(3) nm, c = 1.354 3(4) nm, β= 109.672(4)°, Z= 4. In the complex, Co( Ⅱ ) ion is six-coordinated, forming a distorted octahedron. H-bonding and π-π stacking interaction play a significant role to form and stabilize the three-dimensional structure.

  1. Spin flop relaxation in the quasi-1d Heisenberg antiferromagnet CsMnBr 3 · 2H 2O

    Science.gov (United States)

    Chirwa, M.; Top, J.; Flokstra, J.

    1983-12-01

    The relaxation phenomena associated with the antiferromagnetic to spin-flop phase transition in the quasi one dimensional Heisenberg antiferromagnet CsMnBr 3 · 2H 2O have been determined in the temperature range 1.6-4.2 K using an automatic frequency-sweeping SQUID susceptometer. Below Tλ = 2.17 K the relaxation rate τ -1 displays an exponential temperature dependence given by τ-1 = ω0 exp(- E/ kT) where ω0 = 2.48 × 10 4 s -1 and E/ k = 3.62 K, the activation energy of the relaxation process. Above Tλ broadened absorption curves and flattened Argand diagrams are observed. The ratio K1/ K2 (=0.22 ± 0.02) of the orthorhombic anisotropy constants and a weak power-law temperature dependence of the critical spin-flop field Hcr were determined.

  2. Self-Assembly,Crystal Structure and Magnetic Properties of Three-Dimensional Supramolecular Complex [Ni (hmt)2 (SCN)2 (H2O)2 ] [Ni (SCN)2 (H2O)4 ] (H2O)2 (hmt = hexamethylenetetramine)%三维超分子[Ni(hmt)2(SCN)2(H2O)2][Ni(SCN)2(H2O)4](H2O)2的自组装,晶体结构及磁性质(hmt=六次甲基四胺)

    Institute of Scientific and Technical Information of China (English)

    李纲; 朱玉; 李林科; 侯红卫; 樊耀亭; 杜晨霞

    2002-01-01

    Compound [Ni(hmt) 2(SCN) 2(H2O) 2] [Ni(SCN) 2(H2O) 4] (H2O) 2 (hmt = hexamethylenetetramine) was prepared and structurally characterized by means of X-ray single crystal diffraction.The two neutral units [Ni(hmt)2variable-temperature magnetic susceptibilities (5 ~ 300K) shows that the magnetic behavior obeys the Curie-Weiss law over the whole temperature ranges.

  3. Synthesis and Crystal Structure of a Macrocycle [Cu(dadm)(mal)(H2O)]2·2H2O

    Institute of Scientific and Technical Information of China (English)

    林郑忠; 江飞龙; 陈莲; 洪茂椿

    2004-01-01

    The reaction of 4,4′-diaminodiphenylmethane (dadm), malonic acid (H2mal) and Cu(NO3)2 in aqueous solution results in a discrete binuclear Cu(II) macrocycle: [Cu(dadm)(mal)- (H2O)]2(2H2O. It crystallizes in monoclinic, space group P21/c with a = 15.231(3), b = 11.847(2), c = 9.801(2)A,Z= 106.75(3)o, V = 1693.5(6)A3, Z = 2, C32H40Cu2N4O12, Mr = 799.76, Dc = 1.568 g/cm3, λ(MoK() = 0.71073A, μ = 1.325 mm-1, F(000) = 828, the final R = 0.0531 and Wr = 0.1244 for 3421 observed reflections with I > 2σ(I). Each Cu(II) is coordinated by two oxygen atoms from a mal ligand, two nitrogen atoms from two dadm ligands and a water oxygen atom to form a triangle bipyramidal motif. The title compound possesses a distorted macrocycle enclosed by dadm with approximate dimensions of 8.3A× 5.9A.

  4. CO2, H2O exchange and stomatal regulation of regenerated Camptotheca acuminata plantlets during ex vitro acclimatization

    Institute of Scientific and Technical Information of China (English)

    WANG Hui-mei; LI Yan-hua; GAO Yin-xiang; ZU Yuan-gang

    2006-01-01

    For finding the changes in CO2, H2O exchange and their stomatal regulation during ex vitro acclimatization of regenerated Camptotheca acuminata plantlets, the net photosynthesis rate (Pn), respiration rate (Rd), light compensation point (Lc) and light saturation point (Ls), transpiration rate (Tr), stomatal conductance (gs) and water use efficiency(WUE) were measured during 37 days of ex vitro acclimatization. The results showed that Pn sharply increased until 29 days, then slightly decreased. A substantial decrease in Lc and a substantial increase of Ls in the former two weeks were observed, indicating the light regime enlargement for effective leaf photosynthesis. Tr and gs abruptly decreased during the first week then linearly increased until 29days ex vitro acclimatization, reflecting the strong regulation effect of stomata on water changes of ex vitro acclimating plantlets. Stomatal regulation effect on CO2 exchange was different from that on water exchange, i.e. Pn was almost independent of gs during the first week, while Pn was significantly correlated with gs thereafter (i.e. dual patterns). Different from dual patterns of gs-Pn relation, the Tr monotonously linearly increased with gs. Furthermore, WUE was almost independent on gs during the first week, while a marked decreasing tendency with gs was found thereafter. At the beginning of the acclimatization, WUE was mainly determined by photosynthetic capacity, while transpiration becomes a main determinant factor for WUE from 7 to 37 days' acclimatization.

  5. Structural and Spectroscopic Studies on [Cu(DACH)2(H2O)]Cl2(DACH =1,4-Diazacycloheptane)

    Institute of Scientific and Technical Information of China (English)

    GUO,Ya-Mei(郭亚梅); DU,Miao(杜淼); BU,Xian-He(卜显和)

    2002-01-01

    A penta-coordinated Cu(Ⅱ) complex with 1,4-diazacycloheptane (DACH), [Cu(DACH)2(H2O)]Cl2(1), has been synthesized and characterized by X-ray diffraction, IR spectra,elemental analyses, thermal analyses, UV-Vis and ESR techniques. Complex 1 crystallizes in orthorhombic crystal system, Pbcn space group with a = 1.6075(4), b = 1.0539(3),c=0.9195(3) nm, V=1.5578(7) nm3, Mr=352.79, Z=4, Dc=1.487 g/cm3, final R=0.0451 and wR =0.1294.The structure of 1 indicates that the central Cu(Ⅱ) atom is penta-coordinated by four nitrogen atoms of two DACH moieties at the equatorial positions and a water molecule at the axis position. The coordination geometry of Cu(Ⅱ) could be considered as an approximately ideal square-pyramidal environment. Both DACH rings arrange in cis-form and are predominantly in the boat-boat conformation (80%) with some disorder to the chair-chair conformation (20%). The Cl- anions are hydrogen bonded with the nitrogen donors of the DACH rings and the oxygen donor of the coordinated H2O molecule to form a one-dimensional zigzag linear structure.The solution behaviors of 1 are also discussed in detail by Uvvis and ESR technique.

  6. Measurements of Flow Distortion within the IRGASON Integrated Sonic Anemometer and CO_2/H_2O Gas Analyzer

    Science.gov (United States)

    Horst, T. W.; Vogt, R.; Oncley, S. P.

    2016-07-01

    Wind-tunnel and field measurements are analyzed to investigate flow distortion within the IRGASON integrated sonic anemometer and CO_2/H_2O gas analyzer as a function of wind speed, wind direction and attack angle. The wind-tunnel measurements are complimentary to the field measurements, and the dependence of the wind-tunnel mean-wind-component flow-distortion errors on wind direction agrees well with that of the field measurements. The field measurements exhibit significant overestimation of the crosswind variance and underestimation of the momentum flux with respect to an adjacent CSAT3 sonic, as well as a transfer of turbulent kinetic energy from the streamwise wind component to the cross-stream wind components. In contrast, we find attenuation of only a few percent in the vertical velocity variance and the vertical flux of sonic temperature. The attenuation of the fluxes appears to be caused to a large extent by decorrelation between the horizontal and vertical-velocity components and between the vertical velocity and sonic temperature. Additional flow distortion due to transducer shadowing reduces to some extent the overestimation, but also increases the underestimation of the IRGASON turbulence statistics.

  7. A New Luminescent Complex Cd(Ⅱ)-xanthene-9-carboxylate:[Cd(L)2(H2O)]n

    Institute of Scientific and Technical Information of China (English)

    SHANG Jie; WU Xiao-Yuan; WANG Fei; YANG Wen-Bin; YU Rong-Min; LU Can-Zhong

    2013-01-01

    A new luminescent Cd(Ⅱ) coordination polymer,[Cd(L)2(H2O)]n 1 (HL =xan-thene-9-carboxylic acid),was synthesized hydrothermally and characterized by satisfactory elemental analysis,FT-IR spectra and single-crystal X-ray diffraction.The crystal is of orthorhombic system,space group P212121 with a =6.4548(4),b =13.0876(12),c =27.466(2) (A),V =2320.3(3)(A)3,C28H20CdO7,Mr =580.84,Z =4,Dc =1.663 g/cm3,F(000) =1168,μ =0.990 mm-1,Flack parameter =0.00(2),the final R =0.0296 and wR =0.0691 for 5301 observed reflections (Ⅰ> 2σ(Ⅰ)).1 features a one-dimensional (1D) carboxylate oxygen-bridged inorganic chain,which is further connected by intermolecular hydrogen bonds into a three-dimensional (3D) framework.Moreover,compound 1 exhibits strong photoluminescence in the solid state at room temperature.

  8. Insecticidal Activity of [Cu(H2NTA2].2H2O in Aedes aegypti Larvae (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Alessandra Ramos Lima

    2015-12-01

    Full Text Available The demand for new insecticides and alternative strategies for the population control of Aedes aegypti has stimulated research to obtain new compounds with broad biological activity. Accordingly, the dihydrogen nitrilotriacetate complex of copper (II dihydrate, [Cu(H2NTA2].2H2O, was synthesized by the stoichiometric reaction of nitrilotriacetic acid (H3NTA hydroxide with basic copper carbonate (II (Cu2(OH2CO3 and characterized by the spectroscopic techniques UV-Vis and FT-IR. The biological toxicity in A. aegypti was determined by bioassay using concentrations ranging from 90.0 mg L−1 to 897.4 mg L−1. The LC50 obtained was 146.11 mg L−1 [132.18–160.10] and the LT50 obtained at a concentration of 897.4 mg L−1 was 70.61 min [38.21–94.90]. The results showed that the complex obtained in this work is a potential metal-insecticide. DOI: http://dx.doi.org/10.17807/orbital.v7i4.735 

  9. Supercapacitive performance of hydrous ruthenium oxide (RuO2.H2O) thin films synthesized by chemical route at low temperature

    Indian Academy of Sciences (India)

    P R Deshmukh; S N Pusawale; R N Bulakhe; C D Lokhande

    2013-12-01

    In the present investigation, we report the synthesis of ruthenium oxide (RuO2.H2O) thin films by simple chemical bath deposition (CBD) method at low temperature on the stainless steel substrate. The prepared thin films are characterized for their structural and morphological properties by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR) and scanning electron microscopy (SEM). The structural study revealed that the ruthenium oxide thin films are amorphous. Scanning electron microscopy study shows compact morphology with small overgrown particles on the surface of the substrate. FT–IR study confirms the formation of RuO2.H2O material. The supercapacitor behaviour of RuO2.H2O thin film was studied using cyclic voltammetry (CV) technique in 0.5 M H2SO4 electrolyte. RuO2.H2O film showed maximum specific capacitance of 192 F.g-1 at a scan rate of 20 mV.s-1. The charge–discharge studies of RuO2.H2O carried out at 300 A.cm-2 current density revealed the specific power of 1.5 kW.kg-1 and specific energy of 41.6Wh.kg-1 with 95% coulombic efficiency.

  10. Photocatalytic oxidation of nitric oxide from simulated flue gas by wet scrubbing using ultraviolet/TiO2/H2O2 process

    Institute of Scientific and Technical Information of China (English)

    张波; 仲兆平; 付宗明

    2015-01-01

    Nitric oxide (NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet (UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect. The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10−6 and TiO2/H2O2 solution volume of 600 mL. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process.

  11. On the Impact of HO2-H2O Complexes in the Marine Boundary Layer: A Possible Sink for HO2

    Directory of Open Access Journals (Sweden)

    Alexander Thomas Archibald

    2011-01-01

    Full Text Available The impact of the formation of HO2-H2O adducts following reaction between H2O and HO2 and subsequent reaction of this adduct on HOx, H2O2 and O3 as a function of relative humidity in the marine boundary layer has been investigated using a zero-dimensional box model. The results of simulations with different product yields for the reaction of HO2-H2O with HO2 were compared with base case data derived from current recommendations for tropospheric modelling. It is suggested that inclusion of reactions of the HO2-H2O adduct may provide a significant sink for HO2 which has so far not been considered in models of tropospheric chemistry and depending on reaction products may have a significant impact on H2O2 and O3.

  12. Thermal Decomposition Mechanism and Non-Isothermal Kinetics of Complex of [La2(P-MBA)6(PHEN)2]2H2O

    Institute of Scientific and Technical Information of China (English)

    张建军; 王瑞芬; 白继海; 王淑萍

    2002-01-01

    The complex of [La2(P-MBA)6(PHEN)2]2H2O (P-MBA: p-methylbenzoate and PHEN: 1,10-phenanthroline) was prepared and characterized by elemental analysis and IR spectroscopy. The thermal behavior of [La2(P-MBA)6(PHEN)2]2H2O in dynamic nitrogen atmosphere was investigated by TG-DTG techniques. The results show that the thermal decomposition process of the [La2(P-MBA)6(PHEN)2]2H2O occurs in five steps. The empirical kinetic model for the first-step thermal decomposition obtained by Malek method is SB(m,n). The activation energy E and the pre-exponential factor lnA for this step reaction are 76.4 kJ*mol-1 and 24.92, respectively.

  13. Growth and Solvent Effects of a Promising Nonlinear Optical Sodium Paranitrophenolate Dihydrate (NO2-C6H4-ONa·2H2O) Single Crystal

    Institute of Scientific and Technical Information of China (English)

    B.Milton Boaz; A.Leyo Rajesh; S. Xavier Jesu Raja; S. Jerome Das

    2004-01-01

    Sodium paranitrophenolate dihydrate (NPNa·2H2O) is an excellent semiorganic nonlinear optical (NLO) material, crystallizes both in water and methanol with high degree of transparency. Good optical quality single crystals of dimension upto 18 mmx6 mmx3 mm are obtained by isothermal solvent evaporation technique. The solubility of the crystal in different solvents was measured gravimetrically. The single crystals of NPNa·2H2O show variation in physical properties and growth rate in different solvents. Methanol or ethanol solution yields crystals of bipyramidal shape with clear morphology. However, methanol grown crystal is exhibiting improved hardness parameters and possesses excellent thermal stability as compared to water grown crystals. The effects of solvent on hardness parameter along with thermal and optical properties of NPNa·2H2O was revealed in this paper.

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  15. One-step fabrication of nickel nanocones by electrodeposition using CaCl2·2H2O as capping reagent

    Science.gov (United States)

    Lee, Jae Min; Jung, Kyung Kuk; Lee, Sung Ho; Ko, Jong Soo

    2016-04-01

    In this research, a method for the fabrication of nickel nanocones through the addition of CaCl2·2H2O to an electrodeposition solution was proposed. When electrodeposition was performed after CaCl2·2H2O addition, precipitation of the Ni ions onto the (2 0 0) crystal face was suppressed and anisotropic growth of the nickel electrodeposited structures was promoted. Sharper nanocones were produced with increasing concentration of CaCl2·2H2O added to the solution. Moreover, when temperature of the electrodeposition solutions approached 60 °C, the apex angle of the nanostructures decreased. In addition, the nanocones produced were applied to superhydrophobic surface modification using a plasma-polymerized fluorocarbon (PPFC) coating. When the solution temperature was maintained at 60 °C and the concentration of the added CaCl2·2H2O was 1.2 M or higher, the fabricated samples showed superhydrophobic surface properties. The proposed nickel nanocone formation method can be applied to various industrial fields that require metal nanocones, including superhydrophobic surface modification.

  16. On the Crystal Structure of [Cu(OH)2(H2O)2(4-C5H4NCOOH)2

    Institute of Scientific and Technical Information of China (English)

    Ng Seik Weng

    2003-01-01

    The compound described as [Cu(OH)2(H2O)2(4-C5H4NCOOH)2] in Chin. J. Struct. Chem., 2001, 20: 478-480 is instead the compound [Cu(H2O)4(4-C5H4NCOO)2], whose crystal structure has already been published elsewhere.

  17. Preparation and Kinetics of the Thermal Decomposition of Nanosized CuC2O4-ZnC2O4·2H2O

    Institute of Scientific and Technical Information of China (English)

    CHEN Donghua; HUANG Lianrong; TANG Wanjun

    2006-01-01

    The physical mixture of nanosized CuC2O4-ZnC2O4 · 2H2O,as precursors of CuO-ZnO, have been prepared by the one-step solid state reaction method at room temperature. The thermal decomposition processes taking place in the solid state oxalate mixture of nanometer CuC2 O4-ZnC2O4 · 2H2O have been studied in static air using TG, DSC, XRD and TEM techniques. TEM showed that the grain size of the decomposition product is 5-15 nm. The values of the activation energy Ea were determined using the isoconversional procedure of KAS method and the Ozawa method. The most possible mechanism function f(α) of the thermal decompositions of nanosized CuC2O4-ZnC2O4·2H2O are defined using the comparative method, function models of the decomposition of CuC2O4 and ZnC2O4 follow the same mechanism function "Avrami-Erofeev equation". The pre-exponential factor A is obtained on the basis of Eα and f(α), thus the thermal analysis kinetic triplet of the decompositions of nanosized CuC2 O4 -ZnC2O4·2H2O are determined.

  18. An efficient solvent-free synthesis of meso-substituted dipyrromethanes using SnCl2•2H2O catalysis

    Directory of Open Access Journals (Sweden)

    Kabeer Ahmed Shaikh

    2012-07-01

    Full Text Available Highly rapid and simple methodology has been developed for the quantitative synthesis of meso-substituted dipyrromethanes from lowest pyrrole/aldehyde ratio. The method was carried out by using SnCl2•2H2O as a catalyst under solvent free condition. The method is environmentally friendly, easy to workup, and gives excellent yield of the products.

  19. Ternary Isothermal Diffusion Coefficients of NaCl-MgCl2-H2O at 25 C. 7. Seawater Composition

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D G; Lee, C M; Rard, J A

    2007-02-12

    The four diffusion coefficients D{sub ij} of the ternary system NaCl-MgCl{sub 2}-H{sub 2}O at the simplified seawater composition 0.48877 mol {center_dot} dm{sup -3} NaCl and 0.05110 mol {center_dot} dm{sup -3} MgCl{sub 2} have been remeasured at 25 C. The diffusion coefficients were obtained using both Gouy and Rayleigh interferometry with the highly precise Gosting diffusiometer. The results, which should be identical in principle, are essentially the same within or very close to their combined 'realistic' errors. This system has a cross-term D{sub 12} that is larger than the D{sub 22} main-term, where subscript 1 denotes NaCl and 2 denotes MgCl{sub 2}. The results are compared with earlier, less-precise measurements. Recommended values for this system are (D{sub 11}){sub V} = 1.432 x 10{sup -9} m{sup 2} {center_dot} sec{sup -1}, (D{sub 12}){sub V} = 0.750 x 10{sup -9} m{sup 2} {center_dot} sec{sup -1}, (D{sub 21}){sub V} = 0.0185 x 10{sup -9} m{sup 2} {center_dot} sec{sup -1}, and (D{sub 22}){sub V} = 0.728 x 10{sup -9} m{sup 2} {center_dot} sec{sup -1}.

  20. Structure of double cerium and potassium sulfate, 2K2SO4xCe(SO4)2x2H2O

    International Nuclear Information System (INIS)

    A diffractometric investigation of 2K2SO4xCe(SO4)2x2H2O structure is carried out. The refined compound parameters are equal to: a=12.407(2), b=11.160(2), c=13.539(2) A, β=111.63(1) deg, V=1742.6(8) A3, Z=4, dsub(calcd)=2.747(1) g/cm3, space group P21/c. Atom coordinates, interatomic distances and valent angles are presented. A conclusion is made that the compound of 2K2SO4cxCe(SO4)2x2H2O brutto-composition has K8[Ce2(SO4)8]4H2O structural formula and contains dimeric anions [(SO4)3Ce(μ-SO4)2xCe(SO4)3]8-

  1. Synthesis, crystal structure and EPR studies of vanadyl doped [Co(2-nbH)2(ina)2(H2O)] complex

    Science.gov (United States)

    Bozkurt, Esat; Çelik, Yunus; Çöpür, Fatma; Dege, Necmi; Topcu, Yıldıray; Karabulut, Bünyamin

    2016-08-01

    A novel aquabis(isonicotinamide-κN1)bis(2-nitrobenzoato-κ2O,O‧;κO)cobalt(II), (hereafter [Co(2-nbH)2(ina)2(H2O)]; 2-nbH: 2-nitrobenzoic acid; ina: isonicotinamide), complex was synthesized and characterized by using various techniques. The crystal structure was determined by X-ray diffraction (XRD) method. The magnetic properties of VO2+ doped [Co(2-nbH)2(ina)2(H2O)] complex were obtained by electron paramagnetic resonance (EPR) technique. The angular variation of EPR spectra shows that two different VO2+ complexes are present in the lattice. The FT-IR spectra of this compound were discussed in relation to other compounds containing 2-nitrobenzoato or isonicotinamide ligands. Thermal stability and reactivity of this complex were also studied by thermal analysis methods (TG/DTG/DTA).

  2. LiOH - H2O2 - H2O trinary system study for the selection of optimal conditions of lithium peroxide synthesis

    Science.gov (United States)

    Nefedov, R. A.; Ferapontov, Yu A.; Kozlova, N. P.

    2016-01-01

    Using solubility method the decay kinetics of peroxide products contained in liquid phase of LiOH - H2O2 - H2O trinary system with 2 to 6% by wt hydrogen peroxide content in liquid phase in 21 to 33 °C temperature range has been studied. Conducted studies have allowed to determine temperature and concentration limits of solid phase existence of Li2O2·H2O content, distinctness of which has been confirmed using chemical and qualitative X- ray phase analysis. Stabilizing effect of solid phase of Li2O2·H2O content on hydrogen peroxide decay contained in liquid phase of LiOH - H2O2 - H2O trinary system under conditions of experiments conducted has been shown.

  3. Possible Processes for Origin of First Chemoheterotrophic Microorganisms with Modeling of Physiological Processes of Bacterium Bacillus subtilis as a Model System in 2H2O

    OpenAIRE

    Ignat Ignatov; Oleg Mosin

    2015-01-01

    We studied possible processes for origin of first chemoheterotrophic microorganisms with modeling of physiological processes of a Gram-positive chemoheterotrophic bacterium Bacillus subtilis, producer of purine ribonucleoside inosine as a model system in heavy water. The physiological influence of deuterium on the chemoheterotrophic bacterium B. subtilis was studied on a heavy water (HW) medium with a maximal concentration of 2H2O (89–90 atom% 2H). Also various suitable samples of hot mineral...

  4. Hydrothermal Synthesis and Characterization of a Novel Supramolecular Network Compound [Co(IN2)(H2O)4](IN=Isonicotinate)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel supramolecular compound, [Co(IN)2(H2O)4](1), was synthesized by means of the hydrothermal method and its structure was characterized with elemental analysis, FT-IR spectrum, TGA and X-ray diffraction. Though the unit cell structure of the title compound is only monomeric, all these units as building blocks are assembled into a novel three-dimensional supramolecular network via the widely hydrogen-bonding and π-π stacking interactions.

  5. Deuterium Nuclear Magnetic Resonance Measurements of Blood Flow and Tissue Perfusion Employing 2H2O as a Freely Diffusible Tracer

    Science.gov (United States)

    Ackerman, Joseph J. H.; Ewy, Coleen S.; Becker, Nancy N.; Shalwitz, Robert A.

    1987-06-01

    The use of deuterium oxide (2H2O) is proposed as a freely diffusible nuclear magnetic resonance (NMR) blood flow and tissue perfusion tracer of potential clinical utility. Deuterium is a stable, nonradiative isotope commercially available as 2H2O at enrichment levels of essentially 100%--i.e., 110 molar equivalent deuterium. This high concentration, together with the short relaxation time of the spin 1 (quadrupole) deuterium nuclide, provides substantial sensitivity for NMR spectroscopy. As a result, when 2H2O is administered in a bolus fashion to a specific tissue or organ in vivo, the deuterium NMR intensity time course can be analyzed, using mathematical models developed by others for radiolabeled tracers, to measure the rate of blood flow and tissue perfusion. Such an application is demonstrated herein at a static magnetic field of 8.5 tesla. Using single-compartment flow modeling, hepatic blood flow and tissue perfusion in fasted (18 hr) male Sprague-Dawley rats was determined to be 61 ± 17 (mean ± SD) ml/100 g per min (n = 5).

  6. [Ni(1,10-phenanthroline2(H2O2](NO32: A Simple Coordination Complex with a Remarkably Complicated Structure that Simplifies on Heating

    Directory of Open Access Journals (Sweden)

    Timothy J. Prior

    2011-09-01

    Full Text Available Despite the simple chemical formula, [Ni(1,10-phenanthroline2(H2O2](NO32, crystallizes with a remarkably complicated 3-D hydrogen bonding supramolecular assembly. The title compound crystallizes in the monoclinic space group P21/c, with an unusually long b axis and a large cell volume. A huge asymmetric unit has been identified, containing six discrete [Ni(1,10-phen2(H2O2]2+ cations and twelve nitrate anions. Detailed analyses of the crystal structure and O-H×××O and C-H×××O hydrogen bonding interactions are reported and discussed. In this way the anion-directed assembly of the 3-D structure is illustrated. The thermal and spectroscopic properties of the compound are described. Upon heating to 308 K, the crystal undergoes a phase change to a much simpler structure with a single [Ni(1,10-phen2(H2O2]2+ cation within the asymmetric unit and unit cell volume one sixth of that at low temperature. Although the crystal decomposed during data collection, it was possible to establish the molecular packing in the high temperature form and relate it to that at low temperature.

  7. {[Cu2Br3]n[Cu(H-Leof)2]·2H2O} where Leof is Levofloxacin%{[Cu2Br3]n[Cu(H-Leof)2]·2H2O}(Leof是左氟沙星)

    Institute of Scientific and Technical Information of China (English)

    王锡森; 唐云志; 熊仁根

    2005-01-01

    The crystal structure of {[Cu2Br3]n[Cu(H-Leof)2]· 2H2O} (1) comprises of [Cu(H-Leof)2] + cations, [Cu2Br3]nanions and lattice water molecules. And anion is a 1-D chain formed through alternative Cu-Br dimer and triangular geometry. CCDC: 274841.

  8. Investigation into the effect on structure of oxoanion doping in Na2M(SO4)2·2H2O

    Science.gov (United States)

    Driscoll, L. L.; Kendrick, E.; Wright, A. J.; Slater, P. R.

    2016-10-01

    In this paper an investigation into the effect of transition metal ion and selenate/fluorophosphate doping on the structures of Na2M(SO4)2·2H2O (M=transition metal) materials is reported. In agreement with previous reports, the monoclinic (Kröhnkite) structure is adopted for M=Mn, Fe, Co, Cu, while for the smallest first row divalent transition metal ion, M=Ni, the triclinic (Fairfieldite structure) is adopted. On selenate doping there is a changeover in structure from monoclinic to triclinic for M=Fe, Co, Cu, with the larger Fe2+ system requiring the highest level of selenate to complete the changeover. Thus the results suggest that the relative stability of the two structure types is influenced by the relative size of the transition metal: oxoanion group, with the triclinic structure favoured for small transition metals/large oxoanions. The successful synthesis of fluorophosphate doped samples, Na2M(SO4)2-x(PO3F)x·2H2O was also obtained for M=Fe, Co, Cu, with the results showing a changeover in structure from monoclinic to triclinic for M=Co, Cu for very low levels (x=0.1) of fluorophosphate. In the case of M=Fe, the successful synthesis of fluorophosphates samples was achieved for x≤0.3, although no change in cell symmetry was observed. Rather in this particular case, the X-ray diffraction patterns showed evidence for selective peak broadening, attributed to local disorder as a result of the fluorophosphate group disrupting the H-bonding network. Overall the work highlights how isovalent doping can be exploited to alter the structures of Na2M(SO4)2·2H2O systems.

  9. Synthesis, Structure and Characterization of Two-dimensional Network Copper Complex [ Cu3 (nta) 2(azpy) 2(H2O)2]· 6H2O

    Institute of Scientific and Technical Information of China (English)

    LI,Bao-Long(李宝龙); XU,Yan(徐艳); LIU,Qi(刘琦); WANG,Hua-Qin(王化勤); XU,Zheng(徐正)

    2002-01-01

    The copper(Ⅱ) complex [Cu3(nta)2(azpy)2(H2O)2] @6H2O(nta= nitrilotriacetate, azpy= 4,4'-azobispyridine) has been synthesized and characterized. The X-ray analysis reveals that there are two kinds of copper(Ⅱ) coordination environments.Cu(1) has a distorted square plane symmetry and Cu(2) has a distorted octahedral symmetry. Cu(1)is linked to Cu(2)through nta and bound to Cu(1C) by azpy, and Cu(2) islinked to Cu(2A) through azpy, which extends to two-dimensional network with large rhombus 1.2 nm× 1.7 nm.

  10. Kinetics of Thermal Decomposition of Zn1-xMnxC2O4·2H2O in Air

    Institute of Scientific and Technical Information of China (English)

    CONG, Chang-Jie; HONG, Jian-He; LUO, Shi-Ting; TAO, Hai-Bo; ZHANG, Ke-Li

    2006-01-01

    Thermal decomposition processes taking place in solid state complex of Zn1-xMnxC2O4·2H2O have been investigated in air using TG-DTG/DTA, XRD and TEM techniques. TG-DTG/DTA curves showed that the decomposition proceeded through two well-defined steps with DTA peaks closely to correspond to the weight loss. XRD and formed under nonisothermal conditions, the activation energies were estimated by Friedman and Flynn-Wall-Ozawa(FWO) methods, and the most probable kinetic model has been estimated with multiple linear regression method.kJ/mol, respectively.

  11. Antiferromagnetic three-dimensional order induced by carboxylate bridges in a two-dimensional network of [Cu3(dcp)2(H2O)4] trimers.

    Science.gov (United States)

    King, Philippa; Clérac, Rodolphe; Anson, Christopher E; Coulon, Claude; Powell, Annie K

    2003-06-01

    A new Cu(II) complex, [Cu(3)(dcp)(2)(H(2)O)(4)](n), with the ligand 3,5-pyrazoledicarboxylic acid monohydrate (H(3)dcp) has been prepared by hydrothermal synthesis, and it crystallizes in the monoclinic space group P2(1)/c with a = 11.633(2) A, b = 9.6005(14) A, c = 6.9230(17) A, beta = 106.01(2) degrees, and Z = 2. In the solid state structure of [Cu(3)(dcp)(2)(H(2)O)(4)](n), trinuclear [Cu(3)(dcp)(2)(H(2)O)(4)] repeating units in which two dcp(3-) ligands chelate the three Cu(II) ions with the central Cu(II) ion, Cu(1) (on an inversion center), link to form infinite 2D sheets via syn-anti equatorial-equatorial carboxylate bridges between Cu(2) atoms in adjacent trimers. These layers are further linked by syn-anti axial-equatorial carboxylate bridging between Cu(1) atoms in adjacent sheets resulting in the formation of a crystallographic 3D network. A detailed analysis of the magnetic properties of [Cu(3)(dcp)(2)(H(2)O)(4)](n) reveals that the dcp(3-) ligand acts to link Cu(II) centers in three different ways with coupling constants orders of magnitude apart in value. In the high temperature region above 50 K, the dominant interaction is strongly antiferromagnetic (J/k(B) = -32 K) within the trimer units mediated by the pyrazolate bridges. Below 20 K, the trimer motif can be modeled as an S = 1/2 unit. These units are coupled to their neighbors by a ferromagnetic interaction mediated by the syn-anti equatorial-equatorial carboxylate bridge. This interaction has been estimated at J(2D)/k(B) = +2.8 K on the basis of a 2D square lattice Heisenberg model. Finally, below 3.2 K a weak antiferromagnetic coupling (J(3D)/k(B) = -0.1 K) which is mediated by the syn-anti axial-equatorial carboxylate bridges between the 2D layers becomes relevant to describe the magnetic (T, H) phase diagram of this material.

  12. Kinetics of Thermal Decomposition for Complex [Zn(C16H18FN3O3)2(NO3)2]*2H2O

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The thermal decomposition reaction of the [Zn(NFA)2(NO3)2]*2H2O(NFA=C16H18FN3O3,norfloxacin) was studied in a static atmosphere using TG-DTG and DTA methods. The thermal decomposition processes of the complex were determined and its kinetics was investigated. The kinetic parameters were obtained from analysis of the TG-DTG curves by differential and integral methods. The most pro- bable mechanism for the second stage was suggested by comparision of the kinetic parameters.

  13. Influence of lipids with hydroxyl-containing head groups on Fe2+ (Cu2+)/H2O2-mediated transformation of phospholipids in model membranes.

    Science.gov (United States)

    Olshyk, Viktoriya N; Melsitova, Inna V; Yurkova, Irina L

    2014-01-01

    Under condition of ROS formation in lipid membranes, free radical reactions can proceed in both hydrophobic (peroxidation of lipids, POL) and polar (free radical fragmentation) parts of the bilayer. Free-radical fragmentation is typical for the lipids containing a hydroxyl group in β-position with respect to an ester or amide bond. The present study has been undertaken to investigate free-radical transformations of phospholipids in model membranes containing lipids able to undergo fragmentation in their polar part. Liposomes from egg yolk lecithin containing saturated or monounsaturated glycero- and sphingolipids were subjected to the action of an HO* - generating system - Fe(2+)(Cu(2+))/H2O2/Asc, and the POL products were investigated. In parallel with this, the effects of monoacylglycerols and scavengers of reactive species on Fe(2+)(Cu(2+))/H2O2/Asc - mediated free-radical fragmentation of phosphatidylglycerols were studied. Hydroxyl-containing sphingolipids and glycerolipids, which undergo free-radical fragmentation under such conditions, manifested antioxidant properties in the model membranes. In the absence of HO groups in the lipid structure, the effect was either pro-oxidant or neutral. Monoacylglycerols slowed down the rate of both peroxidation in the hydrophobic part and free-radical fragmentation in the hydrophilic part of phospholipid membrane. Scavengers of reactive species inhibited the fragmentation of phosphatidylglycerol substantially. Thus, the ability of hydroxyl-containing lipids to undergo free-radical fragmentation in polar part apparently makes a substantial contribution to the mechanism of their protector action.

  14. Reactivity of the biphasic trichloroacetonitrile-CH2Cl2/H2O2 system in the epoxidation of soybean oil

    Directory of Open Access Journals (Sweden)

    Martinelli, Márcia

    2002-06-01

    Full Text Available In this work we report on the epoxidation of soybean oil by the trichloroacetonitrile -CH2Cl2/H2O2 byphasic system. The reaction was carried out at room temperature and, most importantly, in non acid conditions which prevent the opening of the oxirane ring. The epoxidized soybean oil was characterized by infrared, 1H and 13C NMR. A maximum conversion of 81 % was achieved in two hours with 86% of selectivity in epoxy groupsEn el presente trabajo informamos sobre la epoxidación de aceite de soja mediante el sistema bifásico tricloroacetonitrilo-CH2Cl2/H2O2. La reacción fue realizada bajo condiciones de temperatura ambiente y, lo más importante, en condición no ácida, lo que evita la apertura del anillo oxirano. El aceite de soja fue caracterizado por infrarrojo y RMN de 1H and 13C. En dos horas se alcanzó una conversión máxima del 81 % obteniéndose una selectividad del 86 % en grupos epóxidos

  15. Kinetics of CO/CO2 and H2/H2O reactions at Ni-based and ceria-based solid-oxide-cell electrodes

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2015-01-01

    The solid oxide electrochemical cell (SOC) is an energy conversion technology that can be operated reversibly, to efficiently convert chemical fuels to electricity (fuel cell mode) as well as to store electricity as chemical fuels (electrolysis mode). The SOC fuel-electrode carries out......, a composite of nickel and yttria/scandia stabilized zirconia (Ni–SZ). Ni–SZ is known to be more active for H2/H2O than for CO/CO2 reactions, but the reported relative activity varies widely. Here we compare AC impedance and DC current–overpotential data measured in the two gas environments for several...... into the porous electrode thickness. Besides showing higher activity for H2/H2O reactions than CO/CO2 reactions, the Ni/SZ interface is more active for oxidation than reduction. On the other hand, we find the opposite behaviour in both cases for CGOn/STN model electrodes, reporting for the first time a higher...

  16. Thermochemical Properties of RE(Gly) 4Im( ClO4) 3· 2H2O(RE = La, Pr, Nd, Sm, Eu)

    Institute of Scientific and Technical Information of China (English)

    何水样; 刘向荣; 宋迪生; 胡荣祖

    2001-01-01

    The enthalpies of solution in water for five new light rare earth ternary complexes RE(Gly)4Im(ClO4)3@ 2H2O (gE =La, Pr, Nd, Sm, Eu; Gly-glycine; Im-imidazole) were measured by means of a Calvet microcalorimeter. The empirical formula of enthalpy of solution (Asol H), relative apparent molar enthalpy ( φLi ), relative partial molar enthalpy ( Li )and enthalpy of dilution (AdilH1,2) were drawn up by the data of entalpies of solution of these complexes. From three plots of the values of standard enthalpy of solution AsolHΘm, φLi,Li) versus the values of ionic radius (r) of the light rare earth elements, the grouping effect of lanthanide was observed, showing that the coordination bond between rare earth ion and ligand possesses a certain extent of the property of a covalent bond. The standard enthalpies of solution in water of similar complexes, Ce(Gly)4Im(ClO4)3@2H2O were estimated according to the plot of AsolHΘm, versus r.

  17. Generation and loss of reactive oxygen species in low-temperature atmospheric-pressure RF He + O2 + H2O plasmas

    International Nuclear Information System (INIS)

    This study focuses on the generation and loss of reactive oxygen species (ROS) in low-temperature atmospheric-pressure RF (13.56 MHz) He + O2 + H2O plasmas, which are of interest for many biomedical applications. These plasmas create cocktails of ROS containing ozone, singlet oxygen, atomic oxygen, hydroxyl radicals, hydrogen peroxide and hydroperoxyl radicals, i.e. ROS of great significance as recognized by the free-radical biology community. By means of one-dimensional fluid simulations (61 species, 878 reactions), the key ROS and their generation and loss mechanisms are identified as a function of the oxygen and water content in the feed gas. Identification of the main chemical pathways can guide the optimization of He + O2 + H2O plasmas for the production of particular ROS. It is found that for a given oxygen concentration, the presence of water in the feed gas decreases the net production of oxygen-derived ROS, while for a given water concentration, the presence of oxygen enhances the net production of water-derived ROS. Although most ROS can be generated in a wide range of oxygen and water admixtures, the chemical pathways leading to their generation change significantly as a function of the feed gas composition. Therefore, care must be taken when selecting reduced chemical sets to study these plasmas. (fast track communication)

  18. Synthesis, characterization, single crystal X-ray structure, EPR and theoretical studies of a new hybrid inorganic-organic compound [Cu(Hdien)2(H2O)2](pnb)4·4H2O and its structural comparison with related [Cu(en)2(H2O)2](pnb)2

    Science.gov (United States)

    Kumar, Santosh; Sharma, Raj Pal; Venugopalan, Paloth; Witwicki, Maciej; Ferretti, Valeria

    2016-11-01

    A new hybrid inorganic-organic compound [Cu(Hdien)2(H2O)2](pnb)4·4H2O (1) (where pnb = p-nitrobenzoate), in which the tridentate ligand diethylenetriamine (dien) shows an unusual coordination behavior acting as a bidentate ligand when present in its monoprotonated form (Hdien+) has been synthesized by the reaction of copper(II) p-nitrobenzoate and slight excess of dien in methanol-water mixture (4:1v/v). Re-crystallization of the violet precipitated product from hot water gave single crystals suitable for X-ray diffraction studies. The newly synthesized compound 1 has been characterized by spectroscopic techniques (UV-Vis, FT-IR, EPR), and theoretical methods (DFT and MRCI/SORCI). Single crystal X-ray structure determination revealed the existence of the cationic species [Cu(Hdien)2(H2O)2]4+, four p-nitrobenzoate as counter anions and four water molecules are present as solvent of crystallization. Packing analyses of title compound as well as of the structurally similar [Cu(en)2(H2O)2](pnb)2,2 has shown similarities in the crystalline architecture that both hybrid inorganic-organic compounds is stabilized by various non-covalent interactions such as N-H⋯O, C-H⋯O, O-H⋯O etc.

  19. Evidence of PVT anomaly boundaries of water at high pressure from compression and NaCl.2H2O dehydration experiments.

    Science.gov (United States)

    Mirwald, P W

    2005-09-22

    Isothermal compression experiments on water have been performed between 0 to 80 degrees C and up to 1.3 GPa pressure. The compressibilities derived from the water compression experiments reveal a nonsmooth PVT behavior forming two anomaly boundaries. These boundaries originate at the melting line of ice III at about 0.25 GPa/-20 degrees C, and of ice VI at about 0.8 GPa/13 degrees C. Both boundaries have a positive sloped course separating three areas of different PVT properties of water. However, this P-T topology is obscured by an unresolved complication in the temperature range of 40-60 degrees C, which allows different topological interpretations of the data. As a cross-check for the compression experiment the dehydration boundary of sodium chloride-dihydrate (NaCl.2H2O) has been determined up to 1.5 GPa. The dehydration curve of NaCl.2H2O which traverses the two anomaly boundaries shows two inflections at the intersection, at 0.27 GPa/12 degrees C and at 0.77 GPa/22 degrees C, respectively. While the isothermal compressibility curves as well as the dP/dT course of the two anomaly boundaries give evidence of two densifications of water, the slope analysis of the inflections of the NaCl-2H2O dehydration curve suggests that the entropy change plays an important role. A recent model of water at high pressure conditions proposes a gradual structural transition from a low density water (LDW) at low pressures to a high density water (HDW) at high pressures. The compression data as well as the inflections of the dehydration boundary indicate, however, two discrete structural changes of water. Data comparison with that model suggests that the anomaly boundary at lower pressure corresponds to a volume fraction [V(HDW)/(V(LDW)+V(HDW))] of 0.8, while the upper one approaches a volume fraction of 1. PMID:16392519

  20. Ab initio studies of O-2(-) (H2O)(n) and O-3(-) (H2O)(n) anionic molecular clusters, n

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Kurten, T.; Enghoff, Martin Andreas Bødker;

    2011-01-01

    that anionic O-2(-)(H2O)n and O-3(-)(H2O)n clusters are thermally stabilized at typical atmospheric conditions for at least n = 5. The first 4 water molecules are strongly bound to the anion due to delocalization of the excess charge while stabilization of more than 4 H2O is due to normal hydrogen bonding....... Although clustering up to 12 H2O, we find that the O-2 and O-3 anions retain at least ca. 80 % of the charge and are located at the surface of the cluster. The O-2(-) and O-3(-) speicies are thus accessible for further reactions. We consider the distributions of cluster sizes as function of altitude before...

  1. Preparation, Characterization and Properties of Ag(Ⅰ) Coordination Polymer [Ag2(bpp) 2(H2O)]·pydc·7H2O

    Institute of Scientific and Technical Information of China (English)

    GUO, Chunyan; WEN, Guilin; WANG, Yaoyu; FU, Aiyun; LERMONTOVA, ElmiraKh; SHI, Qizhen

    2009-01-01

    A new coordination polymer, [Ag2(bpp)2(H2O)]·pydc·7H2O (1), derived from the ligand pyridine-3,5- dicarboxylic acid (H2pydc), has been obtained through a hydrothermal technique [bpp=1,3-bis(4-pyridyl)propane]. Its single crystal structure has been determined by X-ray crystallography. A 2D sheet containing (H2O)12 water units was formed. Interestingly, each pydc dianion bridged two (H2O)12 units and two free water molecules in the con- struction of 2D hydrogen-bonding sheets. Additionally, fluorescent properties, TG analysis, and PXRD for complex 1 were also measured and discussed.

  2. New Supramolecular Complex Assembled through Hydrogen Bonds.Crystal Structure of Co(PMBP-tsc)2·2DMF·2H2O

    Institute of Scientific and Technical Information of China (English)

    UU,Lang(刘浪); JIA,Dian-Zeng(贾殿赠); QIAO,Yong-Min(乔永民); YU,Kai-Bei(郁开北)

    2002-01-01

    The structure of the complex [Co(PMBP-tsc)2.2DMF@2H2O]( PMBP-tsc= 1-phenyl-3-methyl-4-benzoylpyrazol-5-one-thiosemicarbazone) has been determined by X-ray crystallography. It crystallizes in the orthorhombic system, space group Pna21, with lattice parameters a=2.1170(3) nm, b =1.2780(10) nm, c = 1.8956(2) nm, V= 4.5258(9) nm3 and Z=4. The structure shows that Co2+ in the complex is hexacoordinated with a distorted octahedral coordination sphere.The water molecules bridge the adjacent stacks through hydrogen bonds and lead to supramolecular formation with three-dimensional network structure.

  3. Theoretical studies of the optical and EPR spectra for VO^{2+} in Na_3C_6H_5O_7·2H_2O single crystal

    Directory of Open Access Journals (Sweden)

    Ch.-Y. Li

    2015-06-01

    Full Text Available On the basis of the perturbation formulas for a d^1 configuration ion in a tetragonal crystal field, the three optical absorption bands and electron paramagnetic resonance (EPR parameters (g factors g_i and hyperfine structure constants A_i for i = || and ⊥, respectively of VO^{2+} in Na_3C_6H_5O_7·2H_2O (TSCD single crystals were studied using the perturbation theory method. By simulating the calculated optical and EPR spectra to the observed values, local structure parameters and negative signs of the hyperfine structure constants A_i of the octahedral (VO_6^{8-} cluster in TSCD single crystal can be obtained.

  4. Positron total cross sections for collisions with O2, H2O and CH4 in energy range from 30 to 3000eV

    Institute of Scientific and Technical Information of China (English)

    Shi De-Heng; Liu Yu-Fang; Sun Jin-Feng; Zhu Zun-Lue; Yang Xiang-Dong

    2005-01-01

    Total (elastic plus inelastic) cross sections (TCSs) for the scattering of positrons by molecules O2, H2O and CH4 in the energy range from 30 to 3000eV are calculated using the additivity rule model at Hartree-Fock level. A complex optical model potential modified by incorporating the concept of bonded atom which takes into considerationthe overlapping effect of electron clouds between two atoms in a molecule is firstly employed for the TCS calculation of positron-molecule scattering. TCSs are quantitatively compared with those obtained in experiments and other theorieswherever available, and good agreement is obtained in the energy range from 30 to 3000eV. It is shown that the additivity rule model together with the modified complex optical model potential is completely suitable for the TCS calculations of the positron-molecule scattering.

  5. Synthesis and Crystal Structure of a Cyano-bridged Bimetallic Complex K3(TMS)2(H2O)2Cr(CN)6 [TMS = Tetramethylene Sulfone

    Institute of Scientific and Technical Information of China (English)

    CHEN Wei; CHE Yun-Xia; ZHENG Ji-Min

    2005-01-01

    The cyano-bridged bimetallic complex K3(TMS)2(H2O)2Cr(CN)6 with three- dimensional microporous structure was synthesized and characterized. The title complex (C14H20CrK3N, Mr = 601.78) crystallizes in monoclinic, space group C2/c with a = 14.357(4), b = 9.331(3), c = 19.180(6)(A), β = 96.754(5)o, V = 2551.6(13) (A)3, Z = 4, Dc = 1.567 g/m3, μ(MoKα) = 1.141 mm-1, F(000) = 1228, the final R = 0.0440 and wR = 0.0990 for 1760 observed reflections (I > 2σ(I)). In the crystal, two [Cr(CN) 6]3- units, four K+ ions and two oxygen atoms of two TMS molecules are linked to form a sixteen-membered ring and an extended three-dimensional structure.

  6. Oxidation of disinfectants with Cl-substituted structure by a Fenton-like system Cu(2+)/H2O2 and analysis on their structure-reactivity relationship.

    Science.gov (United States)

    Peng, Jianbiao; Li, Jianhua; Shi, Huanhuan; Wang, Zunyao; Gao, Shixiang

    2016-01-01

    As widely used chemicals intended to protect human being from infection of microorganisms, disinfectants are ubiquitous in the environment. Among them chlorine-substituted phenol is a basic structure in many disinfectant molecules. Removal of these pollutants from wastewater is of great concern. The oxidative degradation of antimicrobial agents such as triclosan, chlorofene, and dichlorofene by a Fenton-like system Cu(2+)/H2O2 was examined. Reaction conditions such as temperature, initial concentrations of H2O2 and Cu(2+), and pH were optimized using triclosan as a representative. The degradation kinetics of the above disinfectants followed pseudo-first-order kinetics under the investigated conditions. Fourteen chlorophenols (CPs) with different chlorine substitution were also studied to evaluate the influence of molecular structure on the degradation process in the Cu(2+)/H2O2 system. Fourteen structure-related parameters were calculated using Gaussian 09 program. A quantitative structure-activity relationship (QSAR) model was established using SPSS software with measured rate constant (k) as dependent variable and calculated molecular descriptors as independent variables. A three-parameter model including energy of HOMO (E homo), molar heat capacity at constant volume (Cv(θ)), and the most positive net charge of hydrogen atoms (qH(+)) was selected for k prediction, with correlation coefficient R(2) = 0.878. Analyses of the model demonstrated that the Cv(θ) was the most significant factor affecting the k of chlorophenols. Variance analysis and standard t-value test were used to validate the model. PMID:26408114

  7. Preparation, Crystal Structure, Thermal Decomposition and Explosive Properties of K2(tza)2(H2O) (tza -- Tetrazole-1-acetic Acid)

    Institute of Scientific and Technical Information of China (English)

    WU Bi-Dong; ZHANG Guo-Tao; ZHANG Tong-Lai; YANG Li; ZHANG Jian-Guo; ZHOU Zun-Ning; YU Kai-Bei

    2011-01-01

    A new energetic compound based on the tetrazole-l-acetic acid (tza) and potassium(I) salt, K2(tza)2(-H2O), was synthesized and characterized by elemental analysis and FT-IR spectrum. Its crystal structure was determined by single-crystal X-ray diffraction analysis. The results show that the crystal belongs to the orthorhombic system, space group Pna21 with a =1.11972(17) nm, b = 0.46647(7) nm, c = 2.5158(4) nm, V = 1.3140(3) nm3, K2C6H8N8O5, Mr=350.40 g·mol-1, Dc= 1.771 g.cm-3, μ(MoKa) = 0.759 mm-1, F(000) = 712, Z= 4, R= 0.023 and wR=0.0527 for 2961 observed reflections (I > 2σ(I)). The K(I) cation is six-coordinated with four O atoms from three carboxylate groups, one O atom from one H2O molecule and one N atom from tetrazolyl ring, in which each tza is coordinated in a tridentate chelating bridging coordination mode.The thermal decomposition mechanism of the title complex was studied by DSC and TG-DTG techniques. Under nitrogen atmosphere at a heating rate of 10 K.min-1, the thermal decomposition of the complex contains one main exothermic process between 191.7 and 243.8 C in the DSC curve.Its combustion heat was mensurated by oxygen bomb calorimetry. The non-isothermal kinetics parameters were calculated by the Kissinger's method and Ozawa-Doyle's method, respectively.The sensitivity properties of K2(tza)2(H2O) were also determined with standard methods, which was very sensitive to flame.

  8. Threshold collision-induced dissociation of Sr(2+)(H(2)O)(x) complexes (x=1-6): An experimental and theoretical investigation of the complete inner shell hydration energies of Sr(2+).

    Science.gov (United States)

    Carl, D R; Chatterjee, B K; Armentrout, P B

    2010-01-28

    The sequential bond energies of Sr(2+)(H(2)O)(x) complexes, where x=1-6, are determined by threshold collision-induced dissociation using a guided ion beam tandem mass spectrometer equipped with an electrospray ionization source. The electrospray source produces an initial distribution of Sr(2+)(H(2)O)(x) complexes, where x=6-9. Smaller Sr(2+)(H(2)O)(x) complexes, where x=1-5, are accessed using a recently developed in-source fragmentation technique that takes place in the high pressure region of a rf-only hexapole ion guide. This work constitutes the first experimental study for the complete inner shell of any multiply charged ion. The kinetic energy dependent cross sections are determined over a wide energy range to monitor all possible dissociation products and are modeled to obtain 0 and 298 K binding energies for loss of a single water molecule. These binding energies decrease monotonically for the Sr(2+)(H(2)O) complex to Sr(2+)(H(2)O)(6). Our experimental results agree well with previous literature results obtained by equilibrium and kinetic studies for x=5 and 6. Because there has been limited theory for the hydration of Sr(2+), we also present an in-depth theoretical study on the energetics of the Sr(2+)(H(2)O)(x) systems by employing several levels of theory with multiple effective core potentials for Sr and different basis sets for the water molecules.

  9. 糖精铜水合物[Cu(C7H4NO3S)2(H2O)4]·2H2O的合成及晶体结构%Synthesis and Crystal Structure of Tetraaquabis(saccharinato-N)Copper( Ⅱ ) Dihydrate Compound [Cu(C7H4NO3S)2 (H2O)4]· 2H2O

    Institute of Scientific and Technical Information of China (English)

    曹云丽; 李青彬; 张爽爽

    2012-01-01

    首次以糖精钠、丙氨酸和硫酸铜为原料合成得到糖精铜蓝色块状晶体,采用红外光谱、X-射线单晶衍射对配合物的晶体结构进行了表征.证明该晶体属单斜晶系,空间群为P21/c,晶胞参数为:a=8,4012(19)A,b=16.3605(18)(A),c=7.3479(16)(A),a=90°,β=100.84(2)°,V=991.49(15)(A)3,Z=2,Dc=1.794 g·cm-3,F(000)=550,R=0.0309.结构分析表明,中心Cu2+与4个O原子和2个N原子配位,处于四角双锥八面体配位环境中,4个水分子在赤道平面上与Cu2+配位,晶胞中还包含有2个游离的结晶水,形成了含6个水分子的结晶物.%Tetraaquabis(saccharinato-N) copper(Ⅱ) dihydrate compound [Cu(C7 H4 NO3 S)2 ( H2O)4] ·2H2O is synthesized by using saccharin sodium, alanine, and copper sulfate as raw materials. And its crystal structure is determined by infrared spectrometry and X-ray diffraction single crystal analysis. The crystal is of monoclinic,space group P21/c,a = 8. 4012(19)A,b=16. 3605(18)A,c=7. 3479(16) A,α = 90°,β=100. 84(2)°,V = 991. 49(15)A3,Z=2,Dc= 1.794 g· cm-3,F(000) = 550,R = 0, 0309. Center Cu2+ is located in the four-cor-ner bipyramid coordination environment with coordination of four atoms 0 and two atoms N. Four molecules H2O coordinate to Cu2+ above the equatorial plane,and the crystal cell contains two free crystal water molecules, so it forms the six-water crystal compound.

  10. Analysis of Heterogeneity in CO2, H2O and OH in Centimeter-Sized Obsidian Pyroclasts from Mono Craters, California

    Science.gov (United States)

    Conde, G. D.; Watkins, J. M.

    2014-12-01

    Volcanic tephra deposits typically contain inclusions or fragments of quenched melt that preserve pre-eruptive volatile concentrations within the volcanic conduit. The concentrations of CO2, H2O and OH in obsidian pyroclasts provide information on magma storage depths while gradients in these volatile species provide information on rates and mechanisms of gas loss (or gain) in magma during ascent. We are measuring CO2, H2O and OH profiles and area maps in six randomly selected pyroclastic obsidian clasts from Mono Craters, California using conventional Fourier Transform Infrared Spectroscopy (FTIR). Previous studies of these pyroclasts have focused on spot analyses of volatile concentrations within clast interiors, but our study targets clast rims, bubbles, flow bands, and texturally homogeneous regions of the clasts. The objective is to use the magnitude and spatial distribution of heterogeneities to assess the role of vapor fluxing and to determine timescales of magmatic processes such as bubble growth/resorption and mixing of magma from variable depths. The first clast that we have analyzed is relatively homogeneous in dissolved H2O and OH but exhibits millimeter-scale heterogeneities in dissolved CO2. The concentration of dissolved CO2 varies by a factor of two, ranging from 15 to 30 ppm with a patchy distribution throughout the clast. The patches of high CO2 concentration do not correspond to visible textures within the clast. Total water (H2Ot) varies from 1.5 to 1.7 wt% with higher water concentrations corresponding to darker regions of glass. The distribution of CO2 requires a mechanism for introducing millimeter-scale heterogeneity within minutes to hours prior to the eruption. Our interpretation is that obsidian pyroclasts are assembled during chaotic vertical mixing and thus sample a range of depths within the feeder system. This interpretation is consistent with previous inferences that resorption of bubbles within pyroclasts is caused by repeated

  11. A SAFT Equation of State for the Quaternary H2S-CO2-H2O-NaCl system

    Science.gov (United States)

    Ji, X.; Zhu, C.

    2011-12-01

    Phase equilibria and thermodynamic properties of the quaternary H2S-CO2-H2O-NaCl system were studied using a statistical associating fluid theory (SAFT)-based equation of state (EOS). The understanding of the physical-chemical properties of this system is critical for predicting the consequences of co-injection of CO2 and H2S into geological formations (geological carbon sequestration) as an option for mitigating the global warming trend. Previous studies of the subsystems within this quaternary have provided many parameters for the EOS. In this study, the subsystems of H2S-CO2 and H2S-H2O-NaCl were investigated in order to obtain the cross parameters for the EOS. For the binary system H2S-CO2, cross association between the site H in H2S and the site O in CO2 was allowed and temperature-independent parameters were used to describe this cross association. Meanwhile, a temperature-dependent binary interaction parameter was used to adjust the cross dispersive energy for this binary system. For the H2S-H2O-NaCl system, one temperature-dependent cross parameter was allowed in order to adjust the cross dispersive energy between H2S and ions of Na+ and Cl-. All cross parameters were fitted to the reliable phase equilibrium experimental data. Densities were predicted and compared with available experimental results. Using the EOS developed in this study, we predicted equilibrium composition in both liquid and vapor phases, the equilibrium pressures at a given composition of the H2O-rich phase in electrolyte solutions with NaCl varying from 0 to 4 mol/kgH2O, and the aqueous solution densities. These predictions provide information and guidance for future experiments regarding the thermodynamic properties and phase behaviors in the H2S-CO2-H2O-NaCl system.

  12. Obtention of agricultural gypsum traced on 34 S (Ca34 SO4.2H2O), by chemical reaction between H234 SO4 and Ca(OH)2

    International Nuclear Information System (INIS)

    The gypsum (CaSO4.2H2O) has double function in the soil: as source of calcium and sulfur and reducing agent of aluminum saturation. The sulfur for the plants has acting in the vital functions and it is proven fact increase of the S deficiency in Brazilian soils. The isotope tracer 34 S can elucidate important aspects in the sulfur cycle. The Ca34 SO4.2H2O was obtained by chemical reaction between Ca(OH)2 and H234 SO4 solution. The acid was obtained by chromatography ionic change, using cationic resin Dowex 50WX8 and Na234 SO4 solution. The reaction was realized under slow agitation. After the reaction, the precipitate was separated and dried in ventilated stove at 60 deg C temperature. The Mass of the Ca34 SO4.2H2O produced was determined by method gravimetric. This way, a system contends resin 426 cm3, considering volume of 2.2 liters can be obtained a solution contends 44.2 g of H234 SO4, theoretically could be produced 78.0 g of Ca34 SO4.2H2O approximately. With results of the tests were verified that there was not total precipitation of the Ca34SO4.2H2O. Were produced 73.7± 0.6 g of Ca34 SO4.2H2O representing average income 94.6±0.8 %. The purity of the produced CaSO4.2H2O was 98%. (author)

  13. Experimental investigation of the complete inner shell hydration energies of Ca2+: threshold collision-induced dissociation of Ca(2+)(H2O)x Complexes (x = 2-8).

    Science.gov (United States)

    Carl, Damon R; Armentrout, P B

    2012-04-19

    The sequential bond energies of Ca(2+)(H(2)O)(x) complexes, where x = 1-8, are measured by threshold collision-induced dissociation (TCID) in a guided ion beam tandem mass spectrometer. From an electrospray ionization source that produces an initial distribution of Ca(2+)(H(2)O)(x) complexes where x = 6-8, complexes down to x = 2 are formed using an in-source fragmentation technique. Ca(2+)(H(2)O) cannot be formed in this source because charge separation into CaOH(+) and H(3)O(+) is a lower energy pathway than simple water loss from Ca(2+)(H(2)O)(2). The kinetic energy dependent cross sections for dissociation of Ca(2+)(H(2)O)(x) complexes, where x = 2-9, are examined over a wide energy range to monitor all dissociation products and are modeled to obtain 0 and 298 K binding energies. Analysis of both primary and secondary water molecule losses from each sized complex provides thermochemistry for the sequential hydration energies of Ca(2+) for x = 1-8 and the first experimental values for x = 1-4. Additionally, the thermodynamic onsets leading to the charge separation products from Ca(2+)(H(2)O)(2) and Ca(2+)(H(2)O)(3) are determined for the first time. Our experimental results for x = 1-6 agree well with previously calculated binding enthalpies as well as quantum chemical calculations performed here. Agreement for x = 1 is improved when the basis set on calcium includes core correlation.

  14. Threshold collision-induced dissociation of hydrated magnesium: experimental and theoretical investigation of the binding energies for Mg(2+)(H2O)x complexes (x=2-10).

    Science.gov (United States)

    Carl, Damon R; Armentrout, Peter B

    2013-03-18

    The sequential bond energies of Mg(2+)(H2O)x complexes, in which x=2-10, are measured by threshold collision-induced dissociation in a guided ion beam tandem mass spectrometer. From an electrospray ionization source that produces an initial distribution of Mg(2+)(H2O)x complexes in which x=7-10, complexes down to x=3 are formed by using an in-source fragmentation technique. Complexes smaller than Mg(2+)(H2O)3 cannot be formed in this source because charge separation into MgOH(+)(H2O) and H3O(+) is a lower-energy pathway than simple water loss from Mg(2+)(H2O)3. The kinetic energy dependent cross sections for dissociation of Mg(2+)(H2O)x complexes, in which x=3-10, are examined over a wide energy range to monitor all dissociation products and are modeled to obtain 0 and 298 K binding energies. Analysis of both primary and secondary water molecule losses from each sized complex provides thermochemistry for the sequential hydration energies of Mg(2+) for x=2-10 and the first experimental values for x=2-4. Additionally, the thermodynamic onsets leading to the charge-separation products from Mg(2+)(H2O)3 and Mg(2+)(H2O)4 are determined for the first time. Our experimental results for x=3-7 agree well with quantum chemical calculations performed here and previously calculated binding enthalpies, as well as previous measurements for x=6. The present values for x=7-10 are slightly lower than previous experimental results and theory, but within experimental uncertainties.

  15. Synthesis and Crystal Structure of Co(DMSO)2(H2O)2(SCN)2 with One-dimensional Hydrogen-bonded Structure (DMSO = Dimethylsulfoxide)

    Institute of Scientific and Technical Information of China (English)

    WEI Rong-Min; CHE Yun-Xia; ZHENG Ji-Min

    2006-01-01

    The title complex Co(DMSO)2(H2O)2(SCN)2 has been prepared and structurally characterized. It crystallizes in monoclinic, space group P21/n with a = 5.1981(9), b = 11.944(2), c = 12.646(2) (A), β = 98.686(2)°, V = 776.2(2) (A)3, C6H16CoN2O4S4, Mr = 367.38, Z = 2, Dc = 1.572 g/cm3, F(000) = 378 and μ(MoKa) = 1.646 mm-1. The structure was refined to R = 0.0232 and wR = 0.0645 for 1241 observed reflections with I > 2σ(I). In the title complex, each Co(II) atom is octahedrally coordinated by four O atoms from two DMSO ligands and two water molecules as well as two N atoms from SCN-ions. The title molecules are connected to each other through intermolecular hydrogen bonds to form a 1-D structure extended by eight-membered Co2O4H2 rings.

  16. Synthesis and Crystal Structure of Ni3(admt)6(NCS)6·C2H5OH·2H2O

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Reaction of nickel (Ⅱ) perchlorate with 4-amino-3,5-dimethyl-1,2,4-triaxole(admt)and NG4NCS gave a trinuclear complex Ni3(admtrz)6 (NCS)6·C2H5OH·2H2O,C32H58N30Ni3O3S6.The compound crystallizes in the orthorhombic space group Pbca(#61) with a=13. 551(3) , b=25.146(6), c=16.553(4) A, V=5640(2)A 3, Z=4, Mr=1279.47, Dc=1. 507 g/cm3; μ(Mo-Kα)=12.70 cm-1 and F(000) = 2656. The final refinement with 2543 observed reflections is converged with R= 0. 058 and Rw= 0. 069. In the Ni3 (admt)6 (NCS)6 molecule, the central nickel atom is coordinated in a distorted octahedral environment by four triazole bridges and two thiocyanate bridges. The terminal nickel atoms are in addition coordinated by two thiocyanate and one admtrz ligand, and thus also have a distorted octahedral geometry.Ni-N distances are 2.040(7)-2. 222(7) A, Ni-Ni distances are 3. 411(1) A.

  17. Synthesis and Crystal Structure of a New Mononuclear Copper(Ⅱ) Complex: [Cu(BMI)4(SO4)]·DMF·2H2O

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new copper(II) complex, [Cu(BMI)4(SO4)]·DMF·2H2O (BMI = benzimida- zole), has been synthesized by the treatment of CuCN with 2-mercaptobenzimidazole in the presence of 1,10-phenanthroline, and characterized by single-crystal X-ray diffraction. It crystalli- zes in monoclinic, space group P21/n with a = 17.6260(4), b = 11.1252(3), c = 18.6573(4)(A),β = 107.9010(10)°, V = 3481.45(14)(A)3, Z = 4, C31H35CuN9O7S, Mr = 741.28, F(000) = 1540, Dc = 1.414 g/cm3, μ = 0.746 mm-1, the final R = 0.0649 and wR = 0.1609 for 4382 observed reflections with I > 2σ(I). The Cu(II) atom is coordinated by five unidentate ligands (one sulfate and four benzimidazole ligands) generated in situ, displaying a slightly distorted square pyramid geometry.

  18. Synthesis and Structure of [Cu(OH)2(H2O)2(4-C5H4N-COOH)2

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hydrothermal reaction of isonicotinic acid (4-C5H4N-COOH), Cu(ClO4)2·6H2O and water at 170°C gave the title compound, [Cu(OH)2(H2O)2(4-C5H4N- COOH)2] (1), which was analyzed by single-crystal X-ray diffraction. The complex crystallizes in triclinic space group P ī with unit cell parameters: a = 6.337(2), b = 6.894(3), c = 9.178(3)?. ( = 99.40(3), ( = 105.26(3), ( = 108.17(5)°, V = 354.1(2) ?3, Z = 1, C12H16CuN2O8, Mr = 379.81, Dc = 1.791 Mg/m3, F(000) = 197, ((MoK() = 1.589 mm-1. The final R and wR are 0.068 and 0.170 for 1249 observed reflections with I ≥ 2σ(I). The central copper ion is in a distorted octahedron geometry completed by two nitrogen atoms from carboxylic ligand, two oxygen atoms from hydroxyl groups and two oxygen atoms from coordinated water molecules. The intermolecular hydrogen bonding leads to the formation of a three-dimensional supramolecular structure.

  19. An investigation on the structure, spectroscopy and thermodynamic aspects of Br2((-))(H2O)n clusters using a conjunction of stochastic and quantum chemical methods.

    Science.gov (United States)

    Naskar, Pulak; Chaudhury, Pinaki

    2016-06-28

    In this work we obtained global as well as local structures of Br2((-))(H2O)n clusters for n = 2 to 6 followed by the study of IR-spectral features and thermochemistry for the structures. The way adopted by us to obtain structures is not the conventional one used in most cases. Here we at first generated excellent quality pre-optimized structures by exploring the suitable empirical potential energy surface using stochastic optimizer simulated annealing. These structures are then further refined using quantum chemical calculations to obtain the final structures, and spectral and thermodynamic features. We clearly showed that our approach results in very quick and better convergence which reduces the computational cost and obviously using the strategy we are able to get one [i.e. global] or more than one [i.e. global and local(s)] energetically lower structures than those which are already reported for a given cluster size. Moreover, IR-spectral results and the evolutionary trends in interaction energy, solvation energy and vertical detachment energy for global structures of each size have also been presented to establish the utility of the procedure employed. PMID:27251059

  20. A vibrational spectroscopic study of the silicate mineral analcime - Na2(Al4SiO4O12)·2H2O - A natural zeolite

    Science.gov (United States)

    Frost, Ray L.; López, Andrés; Theiss, Frederick L.; Romano, Antônio Wilson; Scholz, Ricardo

    2014-12-01

    We have studied the mineral analcime using a combination of scanning electron microscopy with energy dispersive spectroscopy and vibrational spectroscopy. The mineral analcime Na2(Al4SiO4O12)·2H2O is a crystalline sodium silicate. Chemical analysis shows the mineral contains a range of elements including Na, Al, Fe2+ and Si. The mineral is characterized by intense Raman bands observed at 1052, 1096 and 1125 cm-1. The infrared bands are broad; nevertheless bands may be resolved at 1006 and 1119 cm-1. These bands are assigned to SiO stretching vibrational modes. Intense Raman band at 484 cm-1 is attributed to OSiO bending modes. Raman bands observed at 2501, 3542, 3558 and 3600 cm-1 are assigned to the stretching vibrations of water. Low intensity infrared bands are noted at 3373, 3529 and 3608 cm-1. The observation of multiple water bands indicate that water is involved in the structure of analcime with differing hydrogen bond strengths. This concept is supported by the number of bands in the water bending region. Vibrational spectroscopy assists with the characterization of the mineral analcime.

  1. Composition dependent behavior in the ternary mixed magnetic insulator Co1-xMnyNix-yCl2·2H2O

    Science.gov (United States)

    DeFotis, G. C.; Hampton, A. S.; Wallin, T. J.; Trowell, K. T.; Pothen, J. M.; Welshhans, E. A.; Havas, K. C.

    2016-05-01

    The properties of ternary mixed magnetic Co1-xMnyNix-yCl2·2H2O are examined by dc magnetization and susceptibility measurements, from 1.8 to 300 K as a function of composition. This is only the second ternary magnetic insulator so studied. The three transition metal chloride dihydrate components are known to differ in the degree of spin anisotropy and in the distribution of ferromagnetic and antiferromagnetic exchange interactions within and between strongly coupled chemical and structural chains. The Curie and Weiss constants, in χM=C/(T-θ) fits to high temperature susceptibilities, are compared with weighted averages of pure component values. The observed Weiss constant is almost uniformly less negative than calculated. Maxima in low temperature susceptibilities vary widely in presence and location with composition. Some compositions exhibit no susceptibility maximum, many exhibit one maximum, and three exhibit two maxima. A T(x,y) diagram is constructed. Magnetization vs field isotherms exhibit different shapes as a function of composition, with hysteresis markedly composition dependent. For three mixtures hysteresis loops are studied as a function of temperature. An activation process model does not describe the temperature dependence well.

  2. Variscite (AlPO4 2H2O from Cioclovina Cave (Sureanu Mountains, Romania: a tale of a missing phosphate

    Directory of Open Access Journals (Sweden)

    Bogdan P. Onac

    2004-04-01

    Full Text Available Recent investigations on a phosphatized sediment sequence in the Cioclovina Cave led to the identification of a second occurrence in Romania (first time in the cave environment of variscite, AlPO4·2H2O. The mineral exists as dull-white, tiny crusts and veinlets within the thick argillaceous material accumulated on the cave floor. Under scanning electron microscope (SEM variscite appears as subhedral to euhedral micron-size crystals. The {111} pseudo-octahedral form is rather common. Variscite was further characterized by means of X-ray diffraction, thermal, vibrational FT-IR and FT-Raman spectroscopy, and by SEM energy-dispersive spectrometry (EDS. The calculated orthorhombic cell parameters are a = 9.823(4, b = 8.562(9, c = 9.620(5 Å, and V = 809.167(6 Å3. The ED spectrum of variscite shows well-resolved Al and P lines confirming thus the presence of the major elements in our compound. The formation of variscite is attributed to the reaction between the phosphate-rich leachates derived from guano and the underlying clay sediments.

  3. Synthesis and Crystal Structure of a Novel Three-dimensional Supramolecular Compound [(AgI3)(4-HBPFA)2(H2O)

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-Fei; LI Jin-Peng; WEI Yong-Li; ZHU Yu; HOU Hong-Wei

    2005-01-01

    The supramolecular compound [(AgI3)(4-HBPFA)2(H2O)] (Mr = 1361.11) was synthesized via the reaction of 1,1(A)-bis[(4-pyridylamino)carbonyl]ferrocene (4-BPFA) with AgI, and structurally characterized by single-crystal X-ray diffraction analysis.Crystal data: monoclinic, space group C2/c, a = 1.6783(3), b = 10.646(2), c = 2.5419(5) (A), β = 93.66(3)o, V = 4532.2(16) (A)3, Z = 4, Dc = 1.995 g/cm3, F(000) = 2632 and μ = 3.158 mm-1.The compound consists of (4- HBPFA)+, (AgI3)2- and H2O.In the structure, the adjacent (4-HBPFA)+ are linked by C-H…O and N-H…N hydrogen bonds into 1-D chains which are further linked by C-H…I and N-H…I hydrogen bonds as well as intermolecular π-π stacking interactions to form a 3-D supramolecular compound.

  4. Synthesis, Crystal Structure and Electrochemical Properties of a One-dimensional Chain Coordination Polymer [Mn(phen)(2,4,6-TMBA)2(H2O)]n

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A one-dimensional chain-like coordination polymer [Mn(phen)(2,4,6-TMBA)2(H2O)]n has been synthesized from 2,4,6-trimethylbenzoic acid, 1,10-phenanthioline and anhydrous manganese(Ⅱ) sulfate and then characterized. Crystal data for this complex: tetragonal, space group I41, a = 2.05643(16), b = 2.05643(16), c = 1.3939(2) nm, V= 5.8946(11) nm3, Mr = 579.54, Z = 8, Dc = 1.306 g/cm3, λ(MoKα) = 0.490 mm-1, F(000) = 2424, S = 0.985, the final R = 0.0411 and wR = 0.0950. The Flack factor is -0.01(2). The crystal structure shows that two neighboring man-ganese(Ⅱ) ions are linked together by one bridge-chelating 2,4,6-trimethylbenzoic group, forming a one-dimensional chain structure. The manganese(Ⅱ) ion is coordinated with two nitrogen atoms of one 1,10-phenanthroline, three oxygen atoms from three 2,4,6-trimethylbenzoic acids and one water oxygen atom, giving a distorted octahedral coordination geometry. The cyclic voltametric behavior of the complex was also investigated.

  5. Photoelectric properties of thin Eu3+-doped TiO2 films sensitized by cis-RuL2(SCN)2·2H2O

    Institute of Scientific and Technical Information of China (English)

    WU Xiaohong; QIN Wei; WANG Song; JIANG Zhaohua; GUO Yun; XIE Zhaoyang

    2006-01-01

    Thin nanocrystalline TiO2 films doped by europium ions (Eu3+) were obtained by the sol-gel method. The photoelectric properties of Eu3+-doped TiO2 film electrode sensitized by cis-RuL2(SCN)2·2H2O(L=cis-2,2'-bipyridine-4,4'-dicarboxlic acid) ruthenium complex were studied. The thin filmswere characterized by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. Effect of doping Eu3+ on microscopic structure and photoelectrical properties were discussed. The result shows that doping europium ions makes specific surface area of these films larger, which contributes toimproving the photoelectric properties. It is found that an optimal compositiondoped with 0.2 mol.% Eu3+ exhibits the highest photoelectric properties. I sc is 0.37 mA·cm-2 , which is 0.17mA·cm-2 bigger than that of un-doped films;Voc is 405 mV, which is 50 mV bigger than thatof un-doped films.

  6. Synthesis and Crystal Structure of a Dicyanamide-bridged One-dimensional Gadolinium(Ⅲ) Complex [Gd(dca)3(phen)2(H2O)]n

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-Fang; KOU Jian-Yi; KOU Hui-Zhong; NI Zhong-Hai; CUI Ai-Li; WANG Ru-Ji

    2005-01-01

    A chainlike coordination polymer [Gd(dca)3(phen)2(H2O)]n (dca = dicyanamide,phen = 1,10-phenanthroline) has been synthesized, and its crystal structure was characterized by X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P21/n with a = 10.6581(13), b = 15.6129(16), c = 17.733(3) (A), β = 90.499(5)°, V = 2950.8(7) (A)3, Z = 4,C30H18GdN13O, Mr = 733.82, Dc= 1.652 g/cm3, F(000) = 1444, λ(MoKα) = 0.71073 (A),μ = 2.297 mm-1, R = 0.0258 and wR = 0.0616 for 4570 observed reflections (I > 2σ(Ⅰ)). In this complex, the gadolinium atom is nine-coordinated by four dca anions, two chelated phen ligands and one H2O molecule in a distorted tricapped trigonal prism. Two bridging dca anions connect the Gd(Ⅲ) ions yielding chainlike polymers that are linked by hydrogen bonds and π-π interactions to form a three-dimensional network.

  7. Study of Protonic Mobility in CaHPO 4·2H 2O (Brushite) and CaHPO 4(Monetite) by Infrared Spectroscopy and Neutron Scattering

    Science.gov (United States)

    Tortet, L.; Gavarri, J. R.; Nihoul, G.; Dianoux, A. J.

    1997-08-01

    We report the first quasi-elastic neutron scattering analysis of proton mobility in the solid electrolyte CaHPO4·2H2O (brushite). We have studied this hydrated phosphate, in powder state, from 190 to 520 K, using an incident wavelength of 5.12 Å. The time of flight spectra are converted inS(Q,ω) structure factor and inelastic frequency distributionP(Q,ω) in the energy range 0-200 meV (0-1600 cm)-1. A quasi-elastic contribution is clearly evidenced above room temperature; it is fitted with a jump model, involving hydrogen bonds. The quasi-elastic and inelastic scattering data are compared with FTIR results. Two kinds of motions are determined: jumps of acidic protons on hydrogen bonds and vibrations of lattice water molecules associated with the motion of their hydrogen atom on hydrogen bonds (Ea≈0.145 eV). Above 450 K the dehydration of the compound is accompanied by the appearance of a long-range diffusive motion and by the disappearance of some low-frequency inelastic bands.

  8. Hydrothermal Synthesis and Structure of a Novel Coordination Polymer Co3(tma)(pda)2(H2O)3]n·nH2O

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qiu-Xiang; BAI Xiao-Jie; CHEN Le-Pei

    2006-01-01

    A novel coordination polymer [Co3(tma)(pda)2(H2O)3]n·nH2O was synthesized by hydrothermal reaction of 3-(3-pyridyl)acrylate acid (pda) and trimesic acid (tma) with CoCl2·6H2O. The structure was characterized by elemental analysis, IR spectroscopy and X-ray single-crystal dif- fraction analysis. It crystallizes in triclinic, space group (P1)with a = 9.569(4), b = 12.562(6), c = 12.666(6)(A), α = 97.321(7), β = 110.295(7), γ = 106.110(7)°, V = 1328.9(10)(A)3, Dc = 1.877 g/cm3, Mr = 751.24, Z = 2, μ = 1.930 mm-1, F(000) = 758, the final R = 0.0392 and wR = 0.0837. The diffraction result shows that Co atoms are linked through pda and tma ligands to form an infinite three-dimensional network.

  9. Solid reaction mechanism of CaHPO4·2H2O + CaCO3 with and without yttria

    Institute of Scientific and Technical Information of China (English)

    WANG Yong; GAO Jiacheng; HU Jinzhu; ZHANG Yan

    2009-01-01

    The effect ofyttria on the solid reaction mechanism ofa CaHPO4·2H2O + CaCO3 system at different temperatures was experimentally stud-ied. The samples with and without yttria were subjected to thermogravimetric/differential scanning calorimetry measurement. The samples were heat treated at the temperatures corresponding to the peaks on the DSC spectra, and the resulted phase compositions were identified by X-ray diffraction. The transformation mechanism was deduced by comparing the phases obtained at different temperatures. The results show that the transformations at below 1073 K are not affected by yttria, but all those at above 1073 K are completely altered. The formation tem-perature of hydroxyapatite decreases by 134 K, and the decomposition temperature increases by 38 K. The polymorphous transformation of Ca3(PO4)2 from β phase to α phase increases by 47 K. The thermodynamic properties of the transformations at above 1073 K are also modi-fied by the addition of yttria; that is, the endothermal peaks are substituted by exothermal peaks.

  10. Thermochemical Properties of the Complexes RE(HSal)3·2H2O (RE=La, Ce, Pr, Nd, Sm)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Five solid rare earth salicylate complexes were synthesized by low hydrated lathanide chloride and salicylic acid. The complexes in this experiment were identified as the general formula RE(Hsal)3·2H2O(RE=La, Ce, Pr, Nd, Sm) by elemental analysis and EDTA volumetric analysis. IR spectra of the complexes show that carboxyl of salicylic acid coordinates to RE3+ ions. Electrochemical behaviors of the complexes on the glass-carbon electrode were researched with cyclic voltammetry (CV). It is indicated that the electrochemical process of the complexes is a one-electron redox process and the electrochemical reversibility of complexes is less than that of the lanthanide chlorides. The constant-volume combustion energies of complexes, ΔcU, were determined with a precise rotating-bomb calorimeter at 298.15 K. Their standard molar enthalpies of combustion, ΔcHθm, and standard molar enthalpies of formation, ΔfHθm, were calculated.

  11. Synthesis and Crystal Structure of an Azide Bridged Binuclear Zinc(Ⅱ) Dimer Containing Taurine Schiff Base [Zn2(C8H9N2O3S)2·(N3)2·(H2O)2]2·2H2O

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi-Min; LI Jia-Ming; XIE Fu-Qing; WANG Yan-Fei

    2006-01-01

    The title complex [Zn2L2(N3)2(H2O)2]·2H2O (L = N-(2-pyridylmethylidene) taurine)has been synthesized in a methanol-water solution. The crystal belongs to monoclinic, space group P21/c with a = 15.8064(10), b = 10.5015(5), c = 17.3193(11) (A), β = 111.314(2)°, V = 2678.2(3) (A)3, C16H26N10O10S2Zn2, Mr = 713.33, Z = 4, Dc = 1.769 g/cm3, μ = 2.017 mm-1 and F(000) =1456. The asymmetric unit consists of two half-molecules of the complex and two water molecules.Four N and two O atoms form the coordination environment of each Zn atom, resulting in a distorted octahedral configuration. The two halves of each independent dimer are related by a crystallographic inversion centre, which lies at the centre of the ring formed by two Zn atoms and the coordinating the ac plane.

  12. 三维超分子化合物[Ag2(tdpc)(bipy)2][ Ag2(bipy)2(H2O)]·12H2O的合成和晶体结构%Synthesis and crystal structure of a 3D supramolecular structure:[ Ag2 (tdpc) (bipy) 2 ] [ Ag2 ( bipy ) 2 ( H2O ) ]· 12H2O

    Institute of Scientific and Technical Information of China (English)

    鲍文丽

    2011-01-01

    A novel compound [Ag(tdpc)(bipy)2][Ag2(bipy)·2H2O has been synthesized from AgNO3, 4,4'-thiodiphthalic acid (H4tdpc) and 4,4'-bipyridine (bipy).The compound shows a 1D chain structure. The Ag...Ag interactions, n-n interactions among bipy ligands and hydrogen-bonds extended the structure into a 3D supramolecular structure.%以银离子、3,3 ',4,4'-二苯硫酮四羧酸阴离子(tdpc)和4,4'-联吡啶(bipy),合成了一种新型化合物[十二水合(3,3',4,4'-二苯硫酮四羧酸)(4,4'-联吡啶)水合银][ Ag2 (tdpc)(bipy)2][ Ag2 (bipy)2 (H2O)]·12H2O,该化合物为链状结构,Ag…Ag相互作用,bipy间的π-π相互作用和氢键作用将化合物联接为三维超分子结构.

  13. First outer-sphere 1,3-diethyl-2-thiobarbituric compounds [M(H2O)6](1,3-diethyl-2-thiobarbiturate)2·2H2O (M = Co2+, Ni2+): Crystal structure, spectroscopic and thermal properties

    Science.gov (United States)

    Golovnev, Nicolay N.; Molokeev, Maxim S.; Lesnikov, Maxim K.; Atuchin, Victor V.

    2016-06-01

    Two new d-element compounds, [Co(H2O)6](Detba)2·2H2O (1) and [Ni(H2O)6](Detba)2·2H2O (2) (HDetba - 1,3-diethyl-2-thiobarbituric acid) were synthesized and characterized by single-crystal and powder X-ray diffraction analysis, TG-DSC and FT-IR. Structural analysis revealed that (1) and (2) are discrete structures, in which M2+ ion (M = Co, Ni) is six-coordinated by water molecules and it forms an octahedron. The outer-sphere Detba- ions and H2O molecules participate in Osbnd H⋯(O/S) intermolecular hydrogen bonds which form the 2D layer. Thermal decomposition includes the stage of dehydration and the following stage of oxidation of Detba- with a release of CO2, SO2, H2O, NH3 and isocyanate gases.

  14. New zinc-glycine-iodide complexes as a product of equilibrium and non-equilibrium crystallization in the Gly - ZnI2 - H2O system

    Science.gov (United States)

    Tepavitcharova, S.; Havlíček, D.; Matulková, I.; Rabadjieva, D.; Gergulova, R.; Plocek, J.; Němec, I.; Císařová, I.

    2016-09-01

    Equilibrium crystallization of two anhydrous complex compounds, [Zn(gly)2I2] and [Zn(gly)I2], and non-equilibrium crystallization of the [Zn3(H2O)4(μ-gly)2I6] complex have been observed in the Gly - ZnI2 - H2O system at 25°C. Different mixed zinc-glycine-iodide-aqua complexes exist in the studied solutions and those with the highest activity are responsible for the crystallization process. The stable [ZnI2O2(2Gly)]0 complexes are responsible for the large equilibrium crystallization field of the compound [Zn(gly)2I2] (monoclinic system, C2/c space group), in whose crystal structure they are incorporated as discrete distorted electroneutral tetrahedra. In zinc-iodide solutions with a low water activity it is more probable that the glycine zwitterions act as bidentate ligands and form polynuclear complexes. We assume the [ZnI2O2(2/2Gly)]0 infinite chains build the compound [Zn(gly)I2], for which we have found a narrow equilibrium crystallization field. We have failed to describe the crystal structure of this compound because of its limited stability in the air. Non-equilibrium crystallization of [Zn3(H2O)4(μ-gly)2I6] (triclinic system, P-1 space group) was demonstrated, with crystal structure built by trinuclear complexes [ZnI3O(1/2Gly)] [ZnO4(4H2O)O2(2/2Gly)(trans)][ZnI3O(1/2Gly)]. The FTIR and Raman spectra and also the thermal behaviour of the three compounds were discussed.

  15. Phase evolution of Na2O-Al2O3-SiO2-H2O gels in synthetic aluminosilicate binders.

    Science.gov (United States)

    Walkley, Brant; San Nicolas, Rackel; Sani, Marc-Antoine; Gehman, John D; van Deventer, Jannie S J; Provis, John L

    2016-04-01

    This study demonstrates the production of stoichiometrically controlled alkali-aluminosilicate gels ('geopolymers') via alkali-activation of high-purity synthetic amorphous aluminosilicate powders. This method provides for the first time a process by which the chemistry of aluminosilicate-based cementitious materials may be accurately simulated by pure synthetic systems, allowing elucidation of physicochemical phenomena controlling alkali-aluminosilicate gel formation which has until now been impeded by the inability to isolate and control key variables. Phase evolution and nanostructural development of these materials are examined using advanced characterisation techniques, including solid state MAS NMR spectroscopy probing (29)Si, (27)Al and (23)Na nuclei. Gel stoichiometry and the reaction kinetics which control phase evolution are shown to be strongly dependent on the chemical composition of the reaction mix, while the main reaction product is a Na2O-Al2O3-SiO2-H2O type gel comprised of aluminium and silicon tetrahedra linked via oxygen bridges, with sodium taking on a charge balancing function. The alkali-aluminosilicate gels produced in this study constitute a chemically simplified model system which provides a novel research tool for the study of phase evolution and microstructural development in these systems. Novel insight of physicochemical phenomena governing geopolymer gel formation suggests that intricate control over time-dependent geopolymer physical properties can be attained through a careful precursor mix design. Chemical composition of the main N-A-S-H type gel reaction product as well as the reaction kinetics governing its formation are closely related to the Si/Al ratio of the precursor, with increased Al content leading to an increased rate of reaction and a decreased Si/Al ratio in the N-A-S-H type gel. This has significant implications for geopolymer mix design for industrial applications.

  16. Phase evolution of Na2O-Al2O3-SiO2-H2O gels in synthetic aluminosilicate binders.

    Science.gov (United States)

    Walkley, Brant; San Nicolas, Rackel; Sani, Marc-Antoine; Gehman, John D; van Deventer, Jannie S J; Provis, John L

    2016-04-01

    This study demonstrates the production of stoichiometrically controlled alkali-aluminosilicate gels ('geopolymers') via alkali-activation of high-purity synthetic amorphous aluminosilicate powders. This method provides for the first time a process by which the chemistry of aluminosilicate-based cementitious materials may be accurately simulated by pure synthetic systems, allowing elucidation of physicochemical phenomena controlling alkali-aluminosilicate gel formation which has until now been impeded by the inability to isolate and control key variables. Phase evolution and nanostructural development of these materials are examined using advanced characterisation techniques, including solid state MAS NMR spectroscopy probing (29)Si, (27)Al and (23)Na nuclei. Gel stoichiometry and the reaction kinetics which control phase evolution are shown to be strongly dependent on the chemical composition of the reaction mix, while the main reaction product is a Na2O-Al2O3-SiO2-H2O type gel comprised of aluminium and silicon tetrahedra linked via oxygen bridges, with sodium taking on a charge balancing function. The alkali-aluminosilicate gels produced in this study constitute a chemically simplified model system which provides a novel research tool for the study of phase evolution and microstructural development in these systems. Novel insight of physicochemical phenomena governing geopolymer gel formation suggests that intricate control over time-dependent geopolymer physical properties can be attained through a careful precursor mix design. Chemical composition of the main N-A-S-H type gel reaction product as well as the reaction kinetics governing its formation are closely related to the Si/Al ratio of the precursor, with increased Al content leading to an increased rate of reaction and a decreased Si/Al ratio in the N-A-S-H type gel. This has significant implications for geopolymer mix design for industrial applications. PMID:26911317

  17. Secondary ion emission from CO2-H2O ice irradiated by energetic heavy ions: Part I. Measurement of the mass spectra

    Science.gov (United States)

    Farenzena, L. S.; Collado, V. M.; Ponciano, C. R.; da Silveira, E. F.; Wien, K.

    2005-05-01

    Secondary ion mass spectrometry is used to investigate ion emission from a frozen-gas mixture (T = 80-90 K) of CO2 and H2O bombarded by MeV nitrogen ions and by 252Cf fission fragments (FF). The aim of the experiments is to produce organic molecules in the highly excited material around the nuclear track and to detect them in the flux of sputtered particles. Such sputter processes are known to occur at the icy surfaces of planetary or interstellar objects. Time-of-flight (TOF) mass spectrometry is employed to identify the desorbed ions. Mass spectra of positive and negative ions were taken for several molecular H2O/CO2 ratios. In special, positive ions induced by MeV nitrogen beam were analyzed for 9 and 18% H2O concentrations of the CO2-H2O ice and negative ions for ~5% H2O. The ion peaks are separated to generate exclusive the spectra of CO2 specific ions, H2O specific ions and hybrid molecular ions, the latter ones corresponding to ions that contain mostly H and C atoms. In the mass range from 10 to 320 u, the latter exhibits 35 positive and 58 negative ions. The total yield of the positive ions is 0.35 and 0.57 ions/impact, respectively, and of negative ions 0.066 ions/impact. Unexpected effects of secondary ion sputtering yields on H2O/CO2 ratio are attributed to the influence of water molecules concentration on the ionization process.

  18. Possible Processes for Origin of First Chemoheterotrophic Microorganisms with Modeling of Physiological Processes of Bacterium Bacillus subtilis as a Model System in 2H2O

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov

    2015-09-01

    Full Text Available We studied possible processes for origin of first chemoheterotrophic microorganisms with modeling of physiological processes of a Gram-positive chemoheterotrophic bacterium Bacillus subtilis, producer of purine ribonucleoside inosine as a model system in heavy water. The physiological influence of deuterium on the chemoheterotrophic bacterium B. subtilis was studied on a heavy water (HW medium with a maximal concentration of 2H2O (89–90 atom% 2H. Also various suitable samples of hot mineral water and sea water derived from different sources of Bulgaria were investigated using IR- and DNES-spectroscopy. It was shown that hot alkaline mineral water with temperature from +65 0C to +95 0C and pH value from 9 to 11 is more suitable for the origination of first organic forms than other analyzed water samples. There were discussed the reactions of condensation and dehydration occurring in alkaline aqueous solutions at t = +65–95 0C and рН = 9–10, resulting in synthesis from separate molecules the larger organic molecules as short polipeptides and pyrines, as well as the possible mechanisms of the deuterium accumulation in form of H2HO in hot water. The metabolism of the bacterium B. subtilis and the resistance to deuterium was also analyzed on an evolutionary level taking into account the hydrological conditions of primodial hydrosphere and the presence of H2HO, as well as the qualitative and quantitative composition of the cellular protein, amino acids and carbohydrates on media with maximum deuterium content. It was demonstrated on the example of chemoheterotrophic bacteria that first microorganisms might have been originated in hot mineral water with Ca2+ (0.5-1.0 g/l at t = + 65-95 0C and pH = 9–11, that is more suitable for maintenance and origin of life than other analyzed water samples.

  19. LiFePO4 Nanostructures Fabricated from Iron(III) Phosphate (FePO4 x 2H2O) by Hydrothermal Method.

    Science.gov (United States)

    Saji, Viswanathan S; Song, Hyun-Kon

    2015-01-01

    Electrode materials having nanometer scale dimensions are expected to have property enhancements due to enhanced surface area and mass/charge transport kinetics. This is particularly relevant to intrinsically low electronically conductive materials such as lithium iron phosphate (LiFePO4), which is of recent research interest as a high performance intercalation electrode material for Li-ion batteries. Many of the reported works on LiFePO4 synthesis are unattractive either due to the high cost of raw materials or due to the complex synthesis technique. In this direction, synthesis of LiFePO4 directly from inexpensive FePO4 shows promise.The present study reports LiFePO4 nanostructures prepared from iron (III) phosphate (FePO4 x 2H2O) by precipitation-hydrothermal method. The sintered powder was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Inductive coupled plasma-optical emission spectroscopy (ICP-OES), and Electron microscopy (SEM and TEM). Two synthesis methods, viz. bulk synthesis and anodized aluminum oxide (AAO) template-assisted synthesis are reported. By bulk synthesis, micro-sized particles having peculiar surface nanostructuring were formed at precipitation pH of 6.0 to 7.5 whereas typical nanosized LiFePO4 resulted at pH ≥ 8.0. An in-situ precipitation strategy inside the pores of AAO utilizing the spin coating was utilized for the AAO-template-assisted synthesis. The template with pores filled with the precipitate was subsequently subjected to hydrothermal process and high temperature sintering to fabricate compact rod-like structures. PMID:26328435

  20. Corrosion study on high power feeding of telecomunication copper cable in 5 wt.% CaSO4.2H2O solution

    Science.gov (United States)

    Shamsudin, Shaiful Rizam; Hashim, Nabihah; Ibrahim, Mohd Saiful Bahri; Rahman, Muhammad Sayuzi Abdul; Idrus, Muhammad Amin; Hassan, Mohd Rezadzudin; Abdullah, Wan Razli Wan

    2016-07-01

    The studies were carried out to find out the best powering scheme over the copper telephone line. It was expected that the application of the higher power feeding could increase the data transfer and capable of providing the customer's satisfaction. To realize the application of higher remote power feeding, the potential of corrosion problem on Cu cables was studied. The natural corrosion behaviour of copper cable in the 0.5% CaSO4.2H2O solution was studied in term of open circuit potential for 30 days. The corrosion behaviour of higher power feeding was studied by the immersion and the planned interval test to determine the corrosion rate as well as the effect of voltage magnitudes and the current scheme i.e. positive direct (DC+) and alternating current (AC) at about 0.40 ± 0.01 mA/ cm2 current density. In the immersion test, both DC+ and AC scheme showed the increasing of feeding voltage magnitude has increased the corrosion rate of Cu samples starting from 60 to 100 volts. It was then reduced at about 100 - 120 volts which may due to the passive and transpassive mechanism. The corrosion rate was slowly reduced further from 120 to 200 volts. Visually, the positively charged of Cu cable was seems susceptible to severe corrosion, while AC scheme exhibited a slight corrosion reaction on the surface. However, the planned interval test and XRD results showed the corrosion activity of the copper cable in the studied solution was a relatively slow process and considered not to be corroded as a partially protective scale of copper oxide formed on the surface.

  1. LiFePO4 Nanostructures Fabricated from Iron(III) Phosphate (FePO4 x 2H2O) by Hydrothermal Method.

    Science.gov (United States)

    Saji, Viswanathan S; Song, Hyun-Kon

    2015-01-01

    Electrode materials having nanometer scale dimensions are expected to have property enhancements due to enhanced surface area and mass/charge transport kinetics. This is particularly relevant to intrinsically low electronically conductive materials such as lithium iron phosphate (LiFePO4), which is of recent research interest as a high performance intercalation electrode material for Li-ion batteries. Many of the reported works on LiFePO4 synthesis are unattractive either due to the high cost of raw materials or due to the complex synthesis technique. In this direction, synthesis of LiFePO4 directly from inexpensive FePO4 shows promise.The present study reports LiFePO4 nanostructures prepared from iron (III) phosphate (FePO4 x 2H2O) by precipitation-hydrothermal method. The sintered powder was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Inductive coupled plasma-optical emission spectroscopy (ICP-OES), and Electron microscopy (SEM and TEM). Two synthesis methods, viz. bulk synthesis and anodized aluminum oxide (AAO) template-assisted synthesis are reported. By bulk synthesis, micro-sized particles having peculiar surface nanostructuring were formed at precipitation pH of 6.0 to 7.5 whereas typical nanosized LiFePO4 resulted at pH ≥ 8.0. An in-situ precipitation strategy inside the pores of AAO utilizing the spin coating was utilized for the AAO-template-assisted synthesis. The template with pores filled with the precipitate was subsequently subjected to hydrothermal process and high temperature sintering to fabricate compact rod-like structures.

  2. Synthesis and Crystal Structure of a Mixed Complex[ Cu(1, 10-phen)(CH2(COO)2)(H2O)]2·3H2O%混配配合物[Cu(1,10-phen)(CH2(COO)2)(H2O)]2·3H2O的合成和晶体结构

    Institute of Scientific and Technical Information of China (English)

    孙绍发; 吴鸣虎; 曾卉一

    2003-01-01

    Blue block crystals of [ Cu( 1,10 - phen) ( CH2 ( COO)2 ) (H2O) ]2· 3H2O were obtained at room temperature over a period from the filtrate which was resulted from the addition of a alcohol solution of 1,10- philolin into the filtered resultant of the reaction of basic cupric carbonate with aqueous propanioic acid.Single - crystal X - ray diffraction analysis indicates that it crystallizes in a triclinic system with space group P1(No.2), α = 11.560(2),b = 11.750(2),c = 12.510(3) A,α =92.13(3)°,β= 105.50(3)°,γ=109.30(3)°, v = 1530.6(5)A3, z = 2, Mr = 781.66, F(000) = 800, Dc = 1. 696 g/cm3, μ(MoKα) =1.467 mm-1, R = 0.0392, and wR2= 0.0967 for 4560 reflections with I > 2.0σ(I). Each Cu atom is coordinated in a distorted square - pyramid geometry by two N atons of 1,10 - philolin, and two O atoms from two carboxyl group of propanioic acid, and one O atom from a coordination water molecule occupying the apical position with a long Cu - O distance. A dimer [Cu(1,10- phen) (CH2(COO)2) (H2O) ]2 is formed by the inter- molecular hydrogen bonding. The crystal structure is formed by the interconnection of the dimers and crystal water molecules via hydrogen bonding.%在碱式碳酸铜与丙二酸水溶液反应后的滤液中加入1,10-(口菲)啰啉的乙醇溶液,放置获得一种蓝色块状的晶体.X-ray衍射显示为三斜P-1群,α=11.560(2),b=11.750(2),c=12.510(3)A,α=92.13(3)°,β=105.50(3)°,γ=109.30(3)°,v=1530.6(5)A3,z=2,Mr=781.66,F(000)=800,Dc=1.696g/cm3,μ(M0Kα)=1.467mm-1,R=0.0392.二聚体[Cu(1,10-phen)(CH2(COO)2)(H2O)]2是通过分子间的氢键形成的.

  3. Investigation of Resolution and Phase Equilibria of NaCl-Ba(H2PO2)2-H2O Trio Salt-Water System at 25 °C Temperature with Isothermal Method

    OpenAIRE

    KUL, Ali Rıza; ERGE, Hasan; ÖZDEK, Uğur

    2014-01-01

    In the present research, solubility, density, conductivity and phase equilibria of Na2Cl2-Ba(H2PO2)2-H2O triple system existing in Na+, Ba+2/Cl-, (H2PO2)-H2O quadrangular mutual water-salt system were investigated by using physicochemical analysis methods. In the first place, 100 mL distilled water was added into a 100 mL volumetric flask and each time 7 g NaCl was added until solubility point of NaCl. Each addition was followed by mixing two hours and leaving one hour. Having established sol...

  4. Face-Centred-Cubic Artificial Opal Embedded with CdS Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    徐岭; 李明海; 张宇; 马懿; 徐骏; 黄信凡; 陈坤基

    2002-01-01

    Highly monodispersed colloidal silica spheres in sub-micrometre size with distribution standard deviation less than 5% were synthesized by a chemical method. Using the self-crystallization of the silica spheres, we successfully obtained the three-dimensional close-packed face-centred-cubic silica matrices and artificial opals. Then,a colloidal photonic crystal embedded with CdS quantum dots (QDs) was also chemically prepared by using artificial opals as a template. A reflection spectra study reveals that both artificial opals with and without CdS QDs possess (111) directional photonic bandgap features.

  5. Determination of Antioxidant Activity of Chinese Herbal Medicine with RHB-Mn2+-H2O2 System by Synchronous Fluorospectrophotometry%罗丹明B-Mn2+-H2O2体系同步荧光分光光度法测定中药的抗氧化活性

    Institute of Scientific and Technical Information of China (English)

    张爱梅; 刘妮娜; 臧运波; 贾晶晶

    2007-01-01

    罗丹明B能产生特征荧光,其激发波长和发射波长分别为554 nm和575 nm.弱碱性介质中Mn2+-H2O2体系产生的羟自由基可迅速氧化罗丹明B使荧光猝灭,而中药水提取物可部分清除溶液中羟自由基,从而使其荧光猝灭程度减弱.用△λ=21 nm的同步荧光分光光度法建立了测定中药抗氧化活性的方法.测试了11种中药的抗氧化活性,以五倍子的抗氧化活性最强.

  6. The role of acid in the formation of hydrogen-bonded networks featuring 4,4'-dicarboxy-2,2'-bipyridine (H2dcbp): Synthesis, structural and magnetic characterisation of {[Cu(H2dcbp)Cl2].H2O}2 and [Cu(H2dcbp)(NO3)2(H2O)

    OpenAIRE

    Tynan, Eithne; Jensen, Paul; Lees, Anthea C.; Moubaraki, Boujemaa; Murray, Keith S.; Kruger, Paul E.

    2005-01-01

    Reported herein are the synthesis, structural and magnetic characterisation of two hydrogen-bonded networks featuring the 4,4?-dicarboxy-2,2?-bipyridine (H2dcbp) ligand: {[Cu(H2dcbp)(Cl)2]·H2O}2 1 and [Cu(H2dcbp)(NO3)2(H2O)] 2. Compounds 1 and 2 result from the reaction of CuCl2 and Cu(NO3)2, respectively, with H2dcbp under hydrothermal conditions in the presence of either HCl or HNO3. The acid ensures that H2dcbp remains protonated and provides the anions required for charge balance irrespec...

  7. Arsenic speciation in synthetic gypsum (CaSO4·2H2O): A synchrotron XAS, single-crystal EPR, and pulsed ENDOR study

    Science.gov (United States)

    Lin, Jinru; Chen, Ning; Nilges, Mark J.; Pan, Yuanming

    2013-04-01

    Gypsum (CaSO4·2H2O) is a major by-product of mining and milling processes of borate, phosphate and uranium deposits worldwide and, therefore, potentially plays an important role in the stability and bioavailability of heavy metalloids, including As, in tailings and surrounding areas. Gypsum containing 1900 and 185 ppm As, synthesized with Na2HAsO4·7H2O and NaAsO2 in the starting materials, respectively, have been investigated by synchrotron X-ray absorption spectroscopy (XAS), single-crystal electron paramagnetic resonance spectroscopy (EPR), and pulsed electron nuclear double resonance spectroscopy (ENDOR). Quantitative analyses of As K edge XANES and EXAFS spectra show that arsenic occurs in both +3 and +5 oxidation states and the As3+/As5+ value varies from 0.35 to 0.79. Single-crystal EPR spectra of gamma-ray-irradiated gypsum reveal two types of arsenic-associated oxyradicals: [AsO3]2- and an [AsO2]2-. The [AsO3]2- center is characterized by principal 75As hyperfine coupling constants of A1 = 1952.0(2) MHz, A2 = 1492.6(2) MHz and A3 = 1488.7(2) MHz, with the unique A axis along the S-O1 bond direction, and contains complex 1H superhyperfine structures that have been determined by pulsed ENDOR. These results suggest that the [AsO3]2- center formed from electron trapping on the central As5+ ion of a substitutional (AsO4)3- group after removal of an O1 atom. The [AsO2]2- center is characterized by its unique A(75As) axis approximately perpendicular to the O1-S-O2 plane and the A2 axis along the S-O2 bond direction, consistent with electron trapping on the central As3+ ion of a substitutional (AsO3)3- group after removal of an O2 atom. These results confirm lattice-bound As5+ and As3+ in gypsum and point to potential application of this mineral for immobilization and removal of arsenic pollution.

  8. A calibration of the triple oxygen isotope fractionation in the SiO2-H2O system and applications to natural samples

    Science.gov (United States)

    Sharp, Z. D.; Gibbons, J. A.; Maltsev, O.; Atudorei, V.; Pack, A.; Sengupta, S.; Shock, E. L.; Knauth, L. P.

    2016-08-01

    It is now recognized that variations in the Δ17O of terrestrial materials resulting from purely mass dependent fractionations, though small, have geological significance. In this study, the δ18O and δ17O values of selected low temperature quartz and silica samples were measured in order to derive the quartz-water fractionation-temperature relationship for the three oxygen isotope system. A 18O/16O quartz-water fractionation equation valid for all temperatures was generated from published high temperature exchange experiments and low temperature empirical estimates and is given by 1000ln αqz-H2O 18O /16O =4.20 (0.11) ×106/T2 - 3.3 (0.2) × 1000/T (T in Kelvins). The equilibrium δ17O-δ18O relationship is given by the equation lnα17O/16O = θlnα18O/16O . The variation of θ with temperature for the quartz-water system was determined empirically using low temperature marine diatoms, microcrystalline quartz and a modern sinter sample. A best fit to the data give the equation θSiO2-H2O = -(1.85 ± 0.04)/T + 0.5305 , indistinguishable from an earlier theoretical estimate. Application of the quartz-water triple isotope system to low temperature samples provides constraints on both temperature and composition of the water with which the silica last equilibrated. Authigenic quartz crystallization temperatures cluster around 50 °C, which are lower than many previous estimates. The combined δ18O and δ17O values of samples considered to be in equilibrium with ocean or meteoric waters can be used to estimate both formation temperatures and the δ18O value of the meteoric water. Unlike other multiple isotopes systems, such as combined H and O isotopes in cherts, the oxygen source and diagenetic potential for both 17O/16O and 18O/16O ratios are identical, simplifying interpretations from ancient samples.

  9. Synthesis, crystal structure and thermal stability properties of Co (3-apac) 2 ( H2O ) 2 complex%配合物Co(3-apac)2(H2O)2的合成、结构与热稳定性

    Institute of Scientific and Technical Information of China (English)

    范广; 杨祖培

    2011-01-01

    A mononuclear complex Co(3-apac)2(H2O)2(1) (3-apac;3-aminopyrazine-2-carboxylic acid)with 3-apac as ligand has been prepared from aqueous solution and characterized by elemental analysis,IR,single crystal X-ray diffraction and thermogravime-tric analysis. Crystal data:monoclinic,space group C2/c,α = 7. 8881 (11) (A),b= 12.7560(18) (A),c= 13.686(2) A,α= 90.00°,β= 91.960(2)°,γ=90.00°,V= 1376.29(A)3,Z=4,μ= 1.26 mm-1,F(000)= 616,S=l. 098,final R indices(1>2α-(1) )R1 =0.0311,ωR2 =0. 0929,for all reflections R1 =0.0314,ωR2 =0. 0756(CCDC:828310).%以3-氨基吡嗪-2-羧酸为配体合成了一个钴的单核配合物Co(3-apac)2(H2O)2(1)(3-apac:3 -氨基吡嗪-2-羧酸),并利用元素分析、红外光谱、单晶X-射线衍射以及热重分析对配合物(1)进行了表征.晶体学数据:单斜晶系,C2/c空间群,a=7.8881 (11)(A),b=12.7560(18)(A),c=13.686(2)(A),α=90.00°,β=91.960(2)°,γ=90.00°,V=1376.29(A)3,Z=4,μ=1.26 mm-1,F(000)=616,S=1.098,最终偏离因子[I>20-(I)]R1=0.0284,wR2 =0.0738,对于全部数据R1=0.0314,wR2 =0.0756(CCDC:828310).

  10. Synthesis, crystal structure and magnetic properties of [Cu2 ( phth )2 ( H2O )2] ∞ ( H2phth = phthalic acid)%[Cu2(phth)2(H2O)2]∞(H2phth=邻苯二甲酸)配位聚合物的合成、晶体结构和磁性研究

    Institute of Scientific and Technical Information of China (English)

    许洁艳; 杨仕平

    2011-01-01

    A complex, [ Cu2 (phth)2 (H2 O)2 ]∞ , (H2 phth = Phthalic acid), has been synthesized through the reaction of Cu2+salt with phthalic acid. It has been characterized by EA, IR, TG and single crystal X-ray diffraction. X-ray single - crystal diffraction shows that each Cu( Ⅱ ) atom is coordinated by six oxygen atoms in a octahedral geometry and the phth anion adopts two types of coordination fashion to bridge Cu( Ⅱ ) atoms. No spin -spin interaction between the adjacent Cu atoms in the polymeric chain was observed from the magnetic experiments. The complex obeys the Curie-Weiss law with Weiss constant C = 0.25 cm3·K·mol -1 ,θ =0.5 K in the high-temperature region.%将CuSO4·6H2O与H2phth(邻苯二甲酸)反应,得到配合物[Cu2(phth)2(H2O)2]∞.通过EA、IR和TG对其进行了表征,单晶X射线衍射对它的结构进行了确证.结构分析表明:Cu(Ⅱ)处在由6个氧原子配位的变形八面体配位几何构型之中,并通过羧基基团的配位作用,构成一维的配位聚合结构,其中邻苯二甲酸配体表现出两种配位形式.TG结果表明:配合物具有很好的热稳定性.磁性研究表明:配合物中的Cu2+与Cu2+之间没有直接的自旋-自旋磁交换作用,只是表现出普通的顺磁行为,根据Curie-Weiss定律拟合得C=0.25 cm3·K·mol-1,θ=0.5 K.

  11. Nickeltalmessite, Ca2Ni(AsO4)2 · 2H2O, a new mineral species of the fairfieldite group, Bou Azzer, Morocco

    Science.gov (United States)

    Chukanov, N. V.; Mukhanova, A. A.; Möckel, S.; Belakovsky, D. I.; Levitskaya, L. A.

    2010-12-01

    Nickeltalmessite, Ca2Ni(AsO4)2 · 2H2O, a new mineral species of the fairfieldite group, has been found in association with annabergite, nickelaustinite, pecoraite, calcite, and a mineral of the chromite-manganochromite series from the dump of the Aït Ahmane Mine, Bou Azzer ore district, Morocco. The new mineral occurs as spheroidal aggregates consisting of split crystals up to 10 × 10 × 20 μm in size. Nickeltalmessite is apple green, with white streak and vitreous luster. The density measured by the volumetric method is 3.72(3) g/cm3; calculated density is 3.74 g/cm3. The new mineral is colorless under a microscope, biaxial, positive: α = 1.715(3), β = 1.720(5), γ = 1.753(3), 2 V meas = 80(10)°, 2 V calc = 60.4. Dispersion is not observed. The infrared spectrum is given. As a result of heating of the mineral in vacuum from 24° up to 500°C, weight loss was 8.03 wt %. The chemical composition (electron microprobe, wt %) is as follows: 25.92 CaO, 1.23 MgO, 1.08 CoO, 13.01 NiO, 52.09 As2O5; 7.8 H2O (determined by the Penfield method); the total is 101.13. The empirical formula calculated on the basis of two AsO4 groups is Ca2.04(Ni0.77Mg0.13Co0.06)Σ0.96 (AsO4)2.00 · 1.91H2O. The strongest reflections in the X-ray powder diffraction pattern [ d, Å ( I, %) ( hkl)] are: 5.05 (27) (001) (100), 3.57 (43) (011), 3.358 (58) (110), 3.202 (100) (020), 3.099 (64) (0 bar 2 1), 2.813 (60), ( bar 1 21), 2.772 (68) (2 bar 1 0), 1.714 (39) ( bar 3 31). The unit-cell dimensions of the triclinic lattice (space group P1 or P) determined from the X-ray powder data are: a = 5.858(7), b = 7.082(12), c = 5.567(6) Å, α = 97.20(4), β = 109.11(5), γ = 109.78(5)°, V = 198.04 Å3, Z = 1. The mineral name emphasizes its chemical composition as a Ni-dominant analogue of talmessite. The type material of nickeltalmessite is deposited at the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, Russia, registration number 3750/1.

  12. Zn3(OH)2V2O7·2H2O/g-C3N4: A novel composite for efficient photodegradation of methylene blue under visible-light irradiation

    Science.gov (United States)

    Wang, Qizhao; Zheng, Longhui; Bai, Yan; Zhao, Jianjun; Wang, Fangping; Zhang, Rong; Huang, Haohao; Su, Bitao

    2015-08-01

    In this work, we used a facile method to prepare a series of Zn3(OH)2V2O7·2H2O/g-C3N4 composites in a 70 °C water bath for 10 h and characterized them by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis diffuse reflectance spectroscopy (DRS), Brunauer-Emmett-Teller (BET), and photoluminescence (PL). Degradation of methylene blue (MB) and phenol were carried out to evaluate the photocatalytic activities of samples under visible light irradiation. Presence of Zn3(OH)2V2O7·2H2O increased surface areas and promoted the charge separation, exerted great influence on the photocatalytic activity and absorption capacity of g-C3N4. In addition, the synergic effect was explained and a possible photocatalytic mechanism was proposed.

  13. Synthesis and Crystal Structure of [NiL2(H2O)2](ClO4)2L=MBPT=4-p-methylphenyl-3,5-bis-(pyridin-2-yl)-1,2,4-triazole

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Nickel (II) complex, [Ni(MBPT)2(H2O)2](ClO4)2 (MBPT=4-p-methylphenyl-3,5-bis-(pyridin-2-yl)-1,2,4-triazole), was synthesized and its crystal structure determined by X-ray diffraction methods.The complex adopts a distorted octahedral environment made up of two bidentate chelating MBPT ligands in the equatorial plane and two water molecules filling the axial positions.

  14. Synthesis, crystal structure and thermal properties of Ca6(C12H14O4)4(CO3)(OH)2(H2O)x – a 3D inorganic hybrid material

    DEFF Research Database (Denmark)

    Nielsen, Renie Birkedal; Norby, Poul; Kongshaug, Kjell Ove;

    2012-01-01

    of Ca6(C12H14O4)4(CO3)(OH)2(H2O)14 is tetragonal, space group I41/amd (141) with a = 29.12 Å, c = 15.85 Å, V = 13 440 Å3 and Z = 8. The compound is classified as a 3D inorganic hybrid material with a 3-dimensional inorganic framework consisting of Ca and O, connected to 1,3-adamantanedicarboxylate...

  15. Nuclear magnetic relaxation in the ferrimagnetic chain compound NiCu(C7H6N2O6)(H2O)3·2H2O : three-magnon scattering?

    International Nuclear Information System (INIS)

    Recent proton spin-lattice relaxation-time (T1) measurements on the ferrimagnetic chain compound NiCu(C7H6N2O6)(H2O)3·2H2O are explained by an elaborately modified spin-wave theory. We give strong evidence of the major contribution to 1/T1 being made by the three-magnon scattering rather than the Raman scattering

  16. Synthesis and structure of 3D heterometallic (3d-4f) coordination polymers: {[Ln_2Cu(pydc)_4(H_2O)_6]·2H_2O}_n

    Institute of Scientific and Technical Information of China (English)

    MA JingXin; HUANG XiaoFeng; WEI RuiPing; LIU WeiSheng

    2009-01-01

    Two new 3D heterometallic (3d-4f) coordination polymers {[Ln_2Cu(pydc)_4(H_2O)_6]·2H_2O}_n [Ln = Eu (1) and Gd (2)] have been synthesized by hydrothermal reactions and characterized by elemental analysis, X-ray single-crystal analyses, and IR spectroscopy. X-ray crystal structure analyses show that 1 and 2 possess 3D networks and strong intramolecular hydrogen bonding interactions which was confirmed by thermogravimetric (TG) analysis.

  17. Nuclear magnetic relaxation in the ferrimagnetic chain compound NiCu(C7H6N2O6)(H2O)3·2H2O : three-magnon scattering?

    Science.gov (United States)

    Hori, Hiromitsu; Yamamoto, Shoji

    2004-12-01

    Recent proton spin-lattice relaxation-time (T1) measurements on the ferrimagnetic chain compound NiCu(C7H6N2O6)(H2O)3·2H2O are explained by an elaborately modified spin-wave theory. We give strong evidence of the major contribution to 1/T1 being made by the three-magnon scattering rather than the Raman scattering.

  18. Air-C2H2-O2 FAAS determination of tin in lead-calcium-tin Alloy%富氧火焰原子吸收光谱法测定铅钙锡合金中的锡

    Institute of Scientific and Technical Information of China (English)

    王嘉盛

    2003-01-01

    采用富氧火焰(Air-C2H2-O2)原子吸收光谱法直接测定铅钙锡合金中0.1%以上的锡.对仪器工作条件、测定体系酸度、共存离子干扰等作了研究.方法准确度高,结果重现性好.

  19. Deuteron and triton production in Pb+Pb collisions at 158 A centre dot GeV.

    CERN Document Server

    Hansen, A G; Bøggild, H; Boissevain, J G; Conin, L; Christiansen, P; Dodd, J; Erazmus, B; Esumi, S; Fabjan, Christian Wolfgang; Ferenc, D; Fields, D E; Franz, A; Gaardhøje, J J; Hansen, A G; Hansen, O; Hardtke, D; Hecke, H V; Holzer, E B; Humanic, T J; Hummel, P; Jacak, B V; Jayanti, R; Kaimi, K; Kaneta, M; Kohama, T; Kopytine, M; Leltchouk, M; Ljubicic, A; Lörstad, B; Martin, L; Maeda, N; Malina, R; Medvedev, A; Murray, M; Ohnishi, H; Paic, G; Pandey, S U; Piuz, François; Pluta, J; Polychronakos, V; Potekhin, M V; Poulard, G; Reichhold, D M; Sakaguchi, A; Simon-Gillo, J; Schmidt-Sørensen, J; Sondheim, W E; Sugitate, T; Sullivan, J P; Sumi, Y; Willis, W J; Wolf, K L; Xu, N; Zachary, D S

    1999-01-01

    NA44 has measured the invariant cross section of deuterons and tritons at non zero p sub t in 158 A centre dot GeV lead on lead collisions at CERN SPS. Normalized transverse mass spectra and coalescence parameters versus p sub t have been calculated showing a significant transverse flow. Radius parameters have been extracted using a simple thermal coalescence model. Results from RQMD+coalescence calculations are compared to the data.

  20. Rice husk ash supported FeCl2·2H2O:A mild and highly efficient heterogeneous catalyst for the synthesis of polysubstituted quinolines by Friedländer heteroannulation

    Institute of Scientific and Technical Information of China (English)

    Farhad Shirini; Somayeh Akbari-Dadamahaleh; Ali Mohammad-Khah

    2013-01-01

    Rice husk ash was used as a new, green, and cheap adsorbent for FeCl3. Characterization of the ob-tained reagent showed that rice husk ash supported FeCl2·2H2O was formed. This reagent is effi-cient at catalyzing the synthesis of multisubstituted quinolines by the Friedländer heteroannulation of o-aminoaryl ketones with ketones orβ-diketones under mild reaction conditions. This method-ology allows for the synthesis of a broad range of substituted quinolines in high yields and with excellent regioselectivity in the absence of a solvent.

  1. The axial mixing influence on the number stages of countercurrent absorbers in absorbing NH3-CO2-H2O mixture in NaCl-H2O system

    Directory of Open Access Journals (Sweden)

    Vladan Micic

    2010-08-01

    Full Text Available This paper investigates the influence of axial or longitudinal mixing of stages on the number stages in a countercurrent absorber in absorbing vapour-gas mixture of NH3-CO2-H2O in the multicomponent system NaCl-H2O. The number stages in ideal mixing of phases NT and the number of stages which involves axial mixing ND were determined. The authors of this paper conclude that the influence of axial mixing does not affect the number stages in the countercurrent absorber. Otherwise, absorption in this concrete system is practically present in the process of soda ash production.

  2. Supramolecular assembly based on a heteropolyanion: Synthesis and crystal structure of Na3(H2O)6[Al(OH)6Mo6O18]$\\cdot$2H2O

    Indian Academy of Sciences (India)

    Vaddypally Shivaiah; Samar K Das

    2005-05-01

    Synthesis and structural characterization of a polyoxometalate compound Na3(H2O)6 [Al(OH)6Mo6O18]$\\cdot$2H2O (1) have been described. Compound 1 exhibits three-dimensional network structure in the solid state, which is assembled by Anderson-type heteropolyanions, [Al(OH)6Mo6O18]$_n^{3n-}$, as building blocks sharing sodium cations. 1 possesses ``sinuous" channels occupied by supramolecular water dimers as guests. Anderson anions, sodium-coordinated water and crystal water are additionally involved in an intricate hydrogen-bonding network in the crystal of 1.

  3. Coordinated bifluoride ions in the first thiofluoride molybdenum triangular cluster complex: synthesis and crystal structure of K5[Mo3S4F7(FHF)2]·2H2O

    Science.gov (United States)

    Mironov, Yu. V.; Yarovoi, S. S.; Solodovnikov, S. F.; Fedorov, V. E.

    2003-08-01

    The first triangular thiofluoride cluster complex of molybdenum K5[Mo3S4F7(FHF)2]·2H2O with unexpected coordination of bifluoride ions has been synthesized by the reaction of Mo3S7Br4 with molten KHF2. The compound was characterized by single crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Cmc21 with four formulas in unit cell of dimensions a=15.1060(20) Å,b=8.7820(9) Å,c=14.3358(13) Å,V=1901.8(4) Å3.

  4. Ionic-liquid-like local structure in $LiNO_3-Ca(NO_3)_2-H_2O$ as studied by ion and solvent nuclei NMR relaxation

    CERN Document Server

    Matveev, Vladimir V; Lähderanta, Erkki

    2010-01-01

    Relaxation rates in the $13mLiNO_3-6,5mCa(NO_3)_2-H_2O$ ternary system have been measured for nuclei of water ($^1H$ and $^{17}O$), anion ($^{14}N$), and both cations ($^7Li$, $^{43}Ca$). The data analysis reveals the system structure as consisting of two main charged units: [Li(H$_2$O)$_4$]$^+$ and [Ca(NO$_3$)$_4$]$^{2-}$. Thus the system presents inorganic ionic liquid like structure.

  5. Metal-containing ligands for mixed-metal polymers: novel Cu(II)-Ag(I) mixed-metal coordination polymers generated from [Cu(2-methylpyrazine-5-carboxylate)2(H2O)].3H2O and silver(I) salts.

    Science.gov (United States)

    Dong, Y B; Smith, M D; zur Loye, H C

    2000-05-01

    One Cu(II)-containing ligand and two Cu(II)-Ag(I) mixed-metal coordination polymers have been synthesized. [Cu(2-methylpyrazine-5-carboxylate)2(H2O)].3H2O (1) was obtained as a molecular complex with two uncoordinated nitrogen donors by the reaction of 2-methylpyrazine-5-carboxylate sodium with CuCl(2).2H2O in water. Compound 1 crystallized in the triclinic space group P1, with a = 10.498(2) A, b = 11.000(2) A, c = 8.1424(16) A, alpha = 98.33(3) degrees, beta = 101.83(3) degrees, gamma = 66.68(3) degrees, and Z = 2. Reactions of 1 with silver(I) salts have been studied. Two Cu(II)-Ag(I) mixed-metal coordination polymers, namely, Ag[Cu(2-methylpyrazine-5-carboxylate)2.(H2O)2](BF4) (2) and Ag[Cu(2-methylpyrazine-5-carboxylate)2.(H2O)2](NO3) (3), have been generated by treating 1 with AgBF4 and AgNO3, respectively. Compound 2 crystallized in the monoclinic space group C2/c, with a = 25.827(5) A, b = 9.6430(19) A, c = 7.4525(15) A, beta = 94.74(3) degrees, and Z = 4. Compound 3 also crystallized in the monoclinic space group C2/c, with a = 25.855(5) A, b = 9.782(2) A, c = 7.1201(14) A, beta = 96.90(3) degrees, and Z = 4. The main structural feature in both 2 and 3 is a zigzag Cu(II)-Ag(I) mixed-metal chain, in which the alternating Cu(II) and Ag(I) centers are linked by 2-methylpyrazine-5-carboxylate spacers. The effect of the nitrate counterion was illustrated by compound 3, in which a novel [Ag+...NO3-] coordination chain has been found which acts as the connector to cross-link the one-dimensional zigzag chains into a three-dimensional network. In addition, an identical interchain O-H...O hydrogen bonding system has been found in both 2 and 3 and has been shown to play a significant role in directing the alignment of the one-dimensional mixed-metal polymer chains in the crystalline state. The magnetic susceptibilities of 2 and 3 were measured and found to follow the Curie law (mu eff = 1.85 for 2 and 1.83 for 3). PMID:11428114

  6. Significance of the direct relaxation process in the low-energy spin dynamics of a one-dimensional ferrimagnet NiCu(C 7H 6N 2O 6)(H 2O) 3·2H 2O

    Science.gov (United States)

    Yamamoto, S.

    2000-11-01

    In response to recent nuclear magnetic resonance measurements on a ferrimagnetic chain compound NiCu(C 7H 6N 2O 6)(H 2O) 3·2H 2O [Solid State Commun. 113 (2000) 433], we calculate the nuclear spin-lattice relaxation rate 1/ T1 in terms of a modified spin-wave theory. Emphasizing that the dominant relaxation mechanism arises from the direct (single-magnon) process rather than the Raman (two-magnon) one, we explain the observed temperature and applied-field dependences of 1/ T1. Ferrimagnetic relaxation phenomena are generally discussed and novel ferrimagnets with extremely slow dynamics are predicted.

  7. Mineral-fluid equilibria in the system CaO-MgO-SiO2-H2O-CO2-NaCl and the record of reactive fluid flow in contact metamorphic aureoles

    OpenAIRE

    Wilhelm Heinrich; S.S. Churakov; Matthias Gottschalk;  

    2004-01-01

    Phase equilibria in the system CaO-MgO-SiO2-CO2-H2O-NaCl are calculated to illustrate phase relations in metacarbonates over a wide range of P-T-X[H2O-CO2-NaCl] conditions. Calculations are performed using the equation of state of Duan et al. (1995) for H2O-CO2-NaCl fluids and the internally consistent data set of Gottschalk (1997) for thermodynamic properties of solids. Results are presented in isothermal-isobarical plots showing stable mineral assemblages as a function of fluid composition....

  8. Synthesis,Crystal Structure and Magnetic Properties of a 1—D Polymer,[Cu(NITpPy)2(H2TCB)(H2O)]·2H2O

    Institute of Scientific and Technical Information of China (English)

    WANG,Li-Ya; LI,Li-Cun; LIAO,Dai-Zheng; JIANG,Zong-Hui; YAN,Shi-Ping

    2003-01-01

    A novel complex[Cu(NITpPy)2(H2TCB)(H2O)]·2H2O (NITpPy=2-(pyrid-4''''''''-yl)-4,4,5,5-tetramethyl-1,3-dioxoimidazo-line;H2TCB=1,5-dicarboxybenzene carboxylic-2,4-diacid)has been synthesized and characterized by X-ray crystallography analysis.The crystal sturcture consists of infinite chains of Cu(NITpPy)2(H2O)units linked by H2TCB ligands.The complex crystallizes in triclinic system with space group P1-.Crystal data:a=1.0594(2)nm,b=1.3830(3)nm,c=1.5551(3)nm,a=67.75(3)°,β=89.83(3)°,γ=70.54(3)°.The variable magnetic susceptibility studies lead to magnetic coupling constant values of J1=-11.18cm-1(Cu-Rad)and J2=-4.06cm-1(Cu-Cu).

  9. 桑色素光度法检测H2O2/Co2+产生的羟自由基%Alizarin violet oxidative assay of hydroxyl radical produced by Co2+/H2O2 reaction

    Institute of Scientific and Technical Information of China (English)

    陈国平; 陈广大

    2004-01-01

    研究了用桑色素的氧化来显色测定Co2++H2O2体系产生羟自由基(·OH)的方法,提出Co2++H2O2桑色素分析新体系并用于羟自由基(·OH)的测定.本方法利用Co2+与H2O2反应,类似Fenton试剂产生羟自由基(·OH),所产生的羟自由基与桑色素作用后使其吸光度降低,利用吸光度值的变化可间接测定所产生的羟自由基,确定了体系最佳实验条件.同时测定抗氧化剂清除羟自由基的实验,证明该体系可作为筛选抗氧化剂的方法之一.

  10. Monitoring dehydration of the organic-inorganic [(C3H7)4N][SnCl5(H2O)]·2H2O compound using simultaneous thermal and Raman studies

    Science.gov (United States)

    Hajlaoui, S.; Chaabane, I.; Guidara, K.; Bulou, A.

    2016-07-01

    In this work we report the experimental studies of the structural phase transition in the [(C3H7)4N]SnCl5(H2O)]·2H2O compound by differential scanning calorimetric (DSC) and Raman spectroscopic. The X-ray powder diffraction study of the [(C3H7)4N][SnCl5(H2O)]·2H2O sample at room temperature showed that this compound is monoclinic and has P121/c1 space group. Differential scanning calorimetric disclosed two types of phase transitions in the temperature range 356-376 (T1) K and at 393 K (T2) characterized, by a loss of water molecules and probably a reconstruction of new anionic parts after T2 transition. The Raman scattering spectra recorded at various temperatures in the wavenumber range from 100 to 3800 cm- 1 covering the domains of existence of changes in the vicinity of the two phase transitions detected by DSC measurement. A detailed study of the spectral parameters (wave number, reduced intensity and the full width at half maximum) as a function of temperature of a chosen band, associated with (νs(Snsbnd O) + νs(Snsbnd Cl)), based on an order-disorder model allowed us to obtain information relative to the activation energy and correlation length.

  11. Synthesis and Crystal Structure of an Organic-inorganic Complex [Hg(DMSO)2(H2O)]2 [GeW12O40]·DMSO·H2O

    Institute of Scientific and Technical Information of China (English)

    Jing Ping WANG; Xiao Di DU; Xian Ying DUAN; Jing Yang NIU

    2006-01-01

    An organic-inorganic mercury coordination compound [Hg(DMSO)2(H2O)]2 [GeW12O40]·DMSO·H2O(DMSO =dimethyl sulfoxide) has been synthesized and characterized by IR, UV spectra, elemental analysis, TG-DTA and X-ray single-crystal diffraction. Structural analysis revealed that in the title compound, the mercury is three-coordinated to show the distorted trigonal cone geometry, and depending on the electrostatic interaction to connect the polyanion [α-GeW12O40]4-. TG-DTA study manifests the decomposition temperature of the polyanion framework in the title compound is 513.5℃, which is much higher than that of the anion framework. It means that the formation of the organic-inorganic mercury coordination compound made the polyanion [α-GeW12O40]4- to be more stable.

  12. Hydrothermal Synthesis and Crystal Structure of Zinc(Ⅱ) Dinicotinate Complex [Zn(nic)2(H2O)4](nic=nicotinic acid):A Three-dimensional Hydrogen-bond Network

    Institute of Scientific and Technical Information of China (English)

    MAO Hong-yan; ZHANG Zong-pei; ZHANG Hong-yun; XU Chen; WANG En-bo; WU Qing-an; ZHU Yu

    2004-01-01

    @@ Introduction Nicotinic acid and its transition-metal comple-xes have become increasingly important due to their potential applications as cosmetics or medicines with antitumor, antibacterial and antifungal activities, and the activity in the maintenance of normal glucose metabolism[1-3], etc. A major research effort has been made to generate such materials and to study their biological activity[4-9]. But few of the previous works have directed towards the structure investigation of these metal complexes[6-9]. So, in this report we aim at testing the effect of hydrothermal synthesis on the formation of the crystal structures of crystalline [Zn(nic)2(H2O)4 ](nic=nicotinic acid).

  13. Synthesis and Structure of an Interlock Network Frame of Cobalt( Ⅱ ) Coordination Polymer {[Co(azpy)2(NCS)2] · 1/4EtOH · 1/2H2O}n (azpy = 4,4' -Azobispyridine)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A compound {[Co(azpy)2(NCS)2]·1/4EtOH·1/2H2O}n(1), where azpy=4,4'- azo-bispyridine, was synthesized and characterized by means of IR, TGA-DTA, magnetic susceptibility and X-ray single crystal diffraction. It consists of two independent sets of fully interlocked two-dimensional networks with the dihedral angle 61. 7°, organized in parallel stacks of the sheets which are made of edge-shared [Co(Ⅱ)]4 squares separated by 0. 906 2 nm, and defined size rhombic channels. The thermal gravimetric analysis indicates that the framework is stable up to 198 C. The variable-temperature magnetic susceptibility measurements indicated that there is a weak antiferromagnetic interaction between the cobalt(Ⅱ) ions in the complex (1).

  14. Synthesis, crystal structure, and characterization of two-dimensional coordination polymers of three heavy rare-earth elements: [RE(5-Nip)(5-HNip)(H2O)2](H2O)2 (RE = Y, Ho, Er)

    International Nuclear Information System (INIS)

    Three new coordination polymers, [RE(5-Nip)(5-HNip)(H2O)2] · 2H2O (RE = Y (I), Ho (II), and Er (III)) were synthesized by hydrothermal reactions of lanthanide nitrates with 5-nitroisophthalic acid (H2Nip), and characterized by IR spectra, elemental analysis, and single-crystal X-ray diffraction. X-ray diffraction studies suggest that all the two-dimensional 5-nitroisophthalic complexes crystallize in the P1-bar space group and are isomorphic. The two-dimensional layer-like structures are constructed by the lanthanide ions bridged by 5-Nip2- ligands, and the layers further packed into 3D complexes through hydrogen bonds and two kinds of π-π stacking interactions. These complexes exhibit high stabilities up to 465 (1), 518 (2), and 528 deg C (3), respectively

  15. Synthesis and crystal structure of an organic-inorganic complex [Cu(DMF)3(H2O)2]2[SiMo12O40]·2H2O

    Institute of Scientific and Technical Information of China (English)

    WANG Jingping; DU Xiaodi; DUAN Xianying; NIU Jingyang

    2007-01-01

    The synthesis and crystal structure of an polyoxometalate-based organic-inorganic complex [Cu(DMF)3(H2O)2]2[SiMo12O40]·2H2O (DMF = N, N-dimethyl formamide) is described in this article. It was characterized using elemental analysis, thermal analysis, infrared, ultraviolet, and electron spin resonance spectroscopic studies. The X-ray crystallography analysis showed that the copper centers are pentacoordinated to show the square pyramidal geometry, and the polyanion [SiMo12O40]4- which is semi-coordinated to the copper(Ⅱ) centers prevents the existence of a sixth ligand. In addition, the intracationic hydrogen interaction enhanced the stability of the copper coordination cation.

  16. Experimental investigation of the EPR parameters and molecular orbital bonding coefficients for VO2+ ion in NaH2PO4·2H2O single crystals

    Science.gov (United States)

    Kalfaoğlu, Emel; Karabulut, Bünyamin

    2016-09-01

    Electron paramagnetic resonance (EPR) spectra of VO2+ ions in NaH2PO4·2H2O single crystal have been studied. The spin-Hamiltonian parameters and molecular orbital bonding coefficients were calculated. The angular variation of the EPR spectra shows two different VO2+ complexes. These are located in different chemical environment and each environment contains four magnetically inequivalent VO2+ sites. The crystal field around VO2+ ion is approximately axially symmetric since a strong V=O bond distorts the crystal lattice. Spin Hamiltonian parameters and molecular orbital bonding coefficients were calculated from the EPR data and the nature of bonding in the complex was discussed together.

  17. DNA-Binding Study of Tetraaqua-bis(p-nitrobenzoatocobalt(II Dihydrate Complex: [Co(H2O4(p-NO2C6H4COO2]·2H2O

    Directory of Open Access Journals (Sweden)

    Hacali Necefoglu

    2007-06-01

    Full Text Available The interaction of [Co(H2O4(p-NO2C6H4COO2]. 2H2O with sheep genomicDNA has been investigated by spectroscopic studies and electrophoresis measurements.The interaction between cobalt(II p-nitrobenzoate and DNA has been followed by gelelectrophoresis while the concentration of the complex was increased from 0 to 14 mM.The spectroscopic study and electrophoretic experiments support the fact that the complexbinds to DNA by intercalation via p-nitrobenzoate into the base pairs of DNA. Themobility of the bands decreased as the concentration of complex was increased, indicatingthat there was increase in interaction between the metal ion and DNA.

  18. Thermodynamic modeling of poorly complexing metals in concentrated electrolyte solutions: an X-ray absorption and UV-Vis spectroscopic study of Ni(II) in the NiCl2-MgCl2-H2O system.

    Science.gov (United States)

    Zhang, Ning; Brugger, Joël; Etschmann, Barbara; Ngothai, Yung; Zeng, Dewen

    2015-01-01

    Knowledge of the structure and speciation of aqueous Ni(II)-chloride complexes is important for understanding Ni behavior in hydrometallurgical extraction. The effect of concentration on the first-shell structure of Ni(II) in aqueous NiCl2 and NiCl2-MgCl2 solutions was investigated by Ni K edge X-ray absorption (XAS) and UV-Vis spectroscopy at ambient conditions. Both techniques show that no large structural change (e.g., transition from octahedral to tetrahedral-like configuration) occurs. Both methods confirm that the Ni(II) aqua ion (with six coordinated water molecules at RNi-O = 2.07(2) Å) is the dominant species over the whole NiCl2 concentration range. However, XANES, EXAFS and UV-Vis data show subtle changes at high salinity (> 2 mol∙kg(-1) NiCl2), which are consistent with the formation of small amounts of the NiCl+ complex (up to 0.44(23) Cl at a Ni-Cl distance of 2.35(2) Å in 5.05 mol∙kg(-1) NiCl2) in the pure NiCl2 solutions. At high Cl:Ni ratio in the NiCl2-MgCl2-H2O solutions, small amounts of [NiCl2]0 are also present. We developed a speciation-based mixed-solvent electrolyte (MSE) model to describe activity-composition relationships in NiCl2-MgCl2-H2O solutions, and at the same time predict Ni(II) speciation that is consistent with our XAS and UV-Vis data and with existing literature data up to the solubility limit, resolving a long-standing uncertainty about the role of chloride complexing in this system. PMID:25885410

  19. Thermodynamic modeling of poorly complexing metals in concentrated electrolyte solutions: an X-ray absorption and UV-Vis spectroscopic study of Ni(II in the NiCl2-MgCl2-H2O system.

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    Full Text Available Knowledge of the structure and speciation of aqueous Ni(II-chloride complexes is important for understanding Ni behavior in hydrometallurgical extraction. The effect of concentration on the first-shell structure of Ni(II in aqueous NiCl2 and NiCl2-MgCl2 solutions was investigated by Ni K edge X-ray absorption (XAS and UV-Vis spectroscopy at ambient conditions. Both techniques show that no large structural change (e.g., transition from octahedral to tetrahedral-like configuration occurs. Both methods confirm that the Ni(II aqua ion (with six coordinated water molecules at RNi-O = 2.07(2 Å is the dominant species over the whole NiCl2 concentration range. However, XANES, EXAFS and UV-Vis data show subtle changes at high salinity (> 2 mol∙kg(-1 NiCl2, which are consistent with the formation of small amounts of the NiCl+ complex (up to 0.44(23 Cl at a Ni-Cl distance of 2.35(2 Å in 5.05 mol∙kg(-1 NiCl2 in the pure NiCl2 solutions. At high Cl:Ni ratio in the NiCl2-MgCl2-H2O solutions, small amounts of [NiCl2]0 are also present. We developed a speciation-based mixed-solvent electrolyte (MSE model to describe activity-composition relationships in NiCl2-MgCl2-H2O solutions, and at the same time predict Ni(II speciation that is consistent with our XAS and UV-Vis data and with existing literature data up to the solubility limit, resolving a long-standing uncertainty about the role of chloride complexing in this system.

  20. Synthesis, Crystal Structure and Thermal Stability of a Novel Hetero-bimetallic Complex: Bis(malonato)tetra-(aqua)calcum(Ⅱ)copper(Ⅱ)%杂-双核配合物[CaCu(C3H2O4)2(H2O)4]n的合成、晶体结构及热稳定性

    Institute of Scientific and Technical Information of China (English)

    傅绪成; 王成刚; 李明田; 王小艳

    2007-01-01

    The title complex, [CaCu(C3H2O4)2(H2O)4]n, with a formula of C6H12CaCuO12 and Mr=379.78 has been synthesized and characterized by single crystal X-ray diffraction structure analysis, elemental analysis, IR spectra and TG-DTG techniques. The results show that the crystal is Orthorhombic, space group Pbcn with a=0.669 21(5)and Z=4. The final R=0.0540 and wR=0.112 8 for 1 189 observed reflections with I>2σ(Ⅰ). The structure of the title complex consists of CaO8 polyhedra and CuO6 elongated octahedra linked together by malonate ligands. The Ca(Ⅱ) cation, on a twofold axis, is coordinated by two water molecules and six malonate O atoms. The Cu(Ⅱ)cation, which lies in a centre of symmetry in an octahedral arrangement, is coordinated by four malonate O atoms Cu distance of 0.762 46(6) nm. The whole 3D structure is maintained and stabilized by the presence of hydrogen bonds. Its thermo gravimetric analysis was determined by TG-DTG techniques. CCDC: 663184.

  1. The adsorption of CO(2)/H(2)O/N(2) on 5A zeolite and silica gel in a packed column in one and two-dimensional flows

    Science.gov (United States)

    Mohamadinejad, Habib

    The purpose of this work is to develop a computer model that simulates the dynamic behavior of a Four-Bed Molecular Sieves (4-BMS) system. The system will be installed on the International Space Station for removal of CO 2/H2O/N2 on four beds that consist of 5A zeolite, 13X zeolite, and Silica gel. Due to the complexity of the actual 4-BMS, separately packed columns of 5A and Silica gel were built and tested using the model results to obtain the mass and heat transfer coefficients necessary for the development of the 4-BMS. This work begins by introducing the adsorption/desorption process in a packed column. The formulation of the simplest model of adsorption in a packed bed is developed assuming that Darcy's law. In this model, the mass and heat transport gradients are assumed to vary only in the axial direction, i.e., one-dimensional flow. The results of temperature and mass transfer breakthrough of one-dimensional flow are compared with the test results for adsorption of CO2/N2 and CO2/H2O/N2 on 5A zeolite. In the packed column near the wall boundary, the velocity decreases due to the viscous forces and the porosity increases exponentially. This near-wall region of higher porosity results in the channeling of fluid close to the wall surface. This channeling causes an early solute breakthrough relative to the center of the column. In order to accommodate the effect of porosity variation on the breakthrough, a two-dimensional model of the packed column is developed. The results of two-dimensional flow are compared with the test results for adsorption of CO2/N2 and CO2/H 2O/N2 on 5A zeolite. This work also investigates the dynamics of H2O adsorption on Silica gel material. A one-dimensional flow of a packed column bed is developed with the assumption that Darcy's law governs the momentum transport. The results of both models are compared with the test results for adsorption of H 2O/N2 on Silica gel. Finally, a computer model based on the obtained parameters of

  2. Nanodiamond-based nanostructures for coupling nitrogen-vacancy centres to metal nanoparticles and semiconductor quantum dots

    Science.gov (United States)

    Gong, Jianxiao; Steinsultz, Nat; Ouyang, Min

    2016-01-01

    The ability to control the interaction between nitrogen-vacancy centres in diamond and photonic and/or broadband plasmonic nanostructures is crucial for the development of solid-state quantum devices with optimum performance. However, existing methods typically employ top-down fabrication, which restrict scalable and feasible manipulation of nitrogen-vacancy centres. Here, we develop a general bottom-up approach to fabricate an emerging class of freestanding nanodiamond-based hybrid nanostructures with external functional units of either plasmonic nanoparticles or excitonic quantum dots. Precise control of the structural parameters (including size, composition, coverage and spacing of the external functional units) is achieved, representing a pre-requisite for exploring the underlying physics. Fine tuning of the emission characteristics through structural regulation is demonstrated by performing single-particle optical studies. This study opens a rich toolbox to tailor properties of quantum emitters, which can facilitate design guidelines for devices based on nitrogen-vacancy centres that use these freestanding hybrid nanostructures as building blocks. PMID:27273426

  3. Nanodiamond-based nanostructures for coupling nitrogen-vacancy centres to metal nanoparticles and semiconductor quantum dots

    Science.gov (United States)

    Gong, Jianxiao; Steinsultz, Nat; Ouyang, Min

    2016-06-01

    The ability to control the interaction between nitrogen-vacancy centres in diamond and photonic and/or broadband plasmonic nanostructures is crucial for the development of solid-state quantum devices with optimum performance. However, existing methods typically employ top-down fabrication, which restrict scalable and feasible manipulation of nitrogen-vacancy centres. Here, we develop a general bottom-up approach to fabricate an emerging class of freestanding nanodiamond-based hybrid nanostructures with external functional units of either plasmonic nanoparticles or excitonic quantum dots. Precise control of the structural parameters (including size, composition, coverage and spacing of the external functional units) is achieved, representing a pre-requisite for exploring the underlying physics. Fine tuning of the emission characteristics through structural regulation is demonstrated by performing single-particle optical studies. This study opens a rich toolbox to tailor properties of quantum emitters, which can facilitate design guidelines for devices based on nitrogen-vacancy centres that use these freestanding hybrid nanostructures as building blocks.

  4. Hydrothermal Assembly and Structural Characterization of a Novel 3D Coordination Polymer: [Cd2Zn(BTC)2(H2O)4]n·2nH2O

    Institute of Scientific and Technical Information of China (English)

    陈建新; 刘世雄

    2005-01-01

    A hydrothermal reaction of 1,3,5-benzene-tricarboxylic acid (H3BTC) with cad- mium acetate, zinc acetate and pyridine led to the formation of pink crystals of [Cd2Zn(BTC)2- (H2O)4]n·2nH2O 1. Single-crystal X-ray diffraction analysis has revealed that 1 (Cd2ZnC18H18O18) crystallizes in the monoclinic system, space group C2/c with a = 19.4328(7), b = 7.1420(3), c = 18.0426(5)(A), β = 118.035(1)o, V = 2210.3(1) (A)3, Mr = 812.49, Dc = 2.442 g/cm3, Z = 4, μ(MoKα) = 3.081 mm-1 and F(000) =1584. A total of 10735 reflections were collected, of which 2544 were unique. The structure was refined to R = 0.0200 and wR = 0.0603 for 2388 observed reflections with I>2σ(I). The crystal structure consists of cadmium(II)/zinc(II) carboxylates of BTC as well as coordination and discrete water molecules. Extension of the coordination geometry around three metal centers (Cd(1), Cd(2) and Zn(1)), two BTC3- ligands and four coordinated water molecules generates a three-dimensional coordination polymer.

  5. Heat capacity and thermodynamical properties of the crystal of [RE2(Glu)2(H2O)8](ClO4)4·H2O (RE=Nd,Eu,Dy)

    Institute of Scientific and Technical Information of China (English)

    WU XinMin; LI Wei; TAN ZhiCheng; QU SongSheng

    2009-01-01

    Thermodynamical data of rare earth complexes with amino acid are important for engineering chemistry and fundamental chemistry.However,they have rarely been reported.In this work,a series of crystalline complexes of rare earth perchlorate coordinated with glutamic acid have been synthesized in water medium,and their thermodynamical data,including the heat capacity in low temperature range and the standard enthalpy of formation,were determined.These complexes were identified to be [RE2(Glu)2(H2O)8](ClO4)4.H2O (RE=Nd,Eu,Dy) by using thermogravimetric analysis (TG),differential thermal analysis (DTA),and chemical and elementary analyses.Their purity has been determined.No melting points were observed for all the three complexes.The heat capacity of the complexes was measured by an adiabatic calorimeter from 79 to 370 K.Abnormal heat capacity values were detected for two of the complexes and the decomposition range of one complex was found.The temperature,enthalpy change and entropy change of the decomposition processes of the three complexes were calculated.The polynomial equations of heat capacity in the experimental temperature range have been obtained by least squares fitting.The standard enthalpy of formation was determined by an isoperibol reaction calorimeter at 298.15 K.

  6. Synthesis and Crystal Structure of Adamantanecarboxylic Acid Complex with Cu(Ⅱ)%金刚烷甲酸铜(Ⅱ)配合物Cu(ada)2(py)2(H2O)的合成和晶体结构

    Institute of Scientific and Technical Information of China (English)

    冯云龙; 胡晓春; 孔黎春

    2002-01-01

    @@ 铜与有机酸形成的配合物对生命体系有着特殊的生物活性和催化作用[1]. 模拟合成生命体系中铜(Ⅱ)与有机酸形成的配合物并对其结构和性能进行研究,对揭示金属酶的结构和认识生命现象具有重要意义[2]. 铜与羧酸作为配位基团的有机酸根形成的配合物已有许多报道[3~5],而以金刚烷基甲酸(adamantanecarboxylic acid,Hada)为配体的金属配合物未见文献报道. 本文以Hada为配体合成了单核铜(Ⅱ)配合物Cu(ada)2(py)2(H2O),对其进行了元素分析和红外光谱表征,并测定了晶体结构.

  7. Optical emission spectroscopy study of premixed C2H4/O2 and C2H4/C2H2/O2 flames for diamond growth with and without CO2 laser excitation

    Science.gov (United States)

    He, X. N.; Gebre, T.; Shen, X. K.; Xie, Z. Q.; Zhou, Y. S.; Lu, Y. F.

    2010-02-01

    Optical emission spectroscopy (OES) measurements were carried out to study premixed C2H4/O2 and C2H4/C2H2/O2 combustion flame for diamond deposition with and without a CO2 laser excitation. Strong emissions from radicals C2 and CH were observed in the visible range in all the OES spectra acquired. By adding a continuous-wave CO2 laser to irradiate the flame at a wavelength of 10.591 μm, the common CO2 laser wavelength, it was discovered that the emission intensities of the C2 and CH radicals were increased due to the laser beam induced excitation. OES measurements of the C2 and CH radicals were performed using different gas combinations and laser powers. The rotational temperatures in the flame were determined by analyzing the spectra of the R-branch of the A2Δ-->X2Π (0, 0) electronic transition near 430 nm (CH band head). Information obtained from the OES spectra, including the emission intensities of the C2 and CH radicals, the intensity ratios, and the rotational temperatures, was integrated into the study of diamond deposition on tungsten carbide substrates for mechanism analysis of the laser induced vibrational excitation and laser-assisted diamond deposition.

  8. Synthesis,Characterization,and DNA Binding Properties of Dinuclear Copper(Ⅱ)Complex [Cu2(TATP)2(L-Leu)2(CIO4)2]2°2H2O

    Institute of Scientific and Technical Information of China (English)

    GU Qin; LIN Qing-bin; LIU Ying-ju; LE Xue-yi; FENG Xiao-long

    2008-01-01

    A dinuclear copper(Ⅱ) complex [Cu2(TATP)2(L-Leu)2(ClO4)2]2.2H2O was synthesized and characterized,where,TATP=1,4,8,9-tetraazatriphenylene,and L-Leu=L-leucinate,The complex was crystallized in the triclinic space group P1,with two independent molecules in a unit cell,Two Cu(Ⅱ) ions in each complex[Cu2(TATP)2(L-Leu)2(ClO4)2]molecule were found to be in different coordination geometries,i.e.,Cu2 or Cu4 of a distorted square-pyramidal geometry coordinated with two nitrogens of TATP,the amino nitrogen and one carboxylate oxygen of L-Leu and one oxygen of perchlorate,and Cul or Cu3 with an octahedral geometry coordinated with the above stated similar coordinated atoms,and another carboxylate oxygen of L-Leu coordinating to Cu2 or Cu4,The complex can interact with CT-DNA by an intercalative mode and cleave pBR322 DNA in the presence of ascorbate.

  9. Short Wave upwelling Radiative Flux (SWupRF) within NIR range for the selected greenhouse wavelength bands of O2, H2O, CO2 and CH4 by Argus 1000 along with GENSPECT line by line radiative transfer model

    CERN Document Server

    Siddiqui, Rehan; Salem, Naif Al; Quine, Brendan M

    2016-01-01

    This new study develops an algorithm for Short Wave upwelling Radiative Flux (SWupRF) for the spectral variations within near infrared (NIR) from 1100 to 1700 nm wavelength band based on remote sensing data set of Argus 1000 micro-spectrometer observations. We calculate the SWupRF by investigating the total radiative flux due to O2, H2O, CO2 and CH4 and also by the individual gas within the selected wavelength bands of interest. A GENSPECT synthetic line by line radiative transfer model is applied to perform radiative transfer simulations to calculate the radiative flux by varying surface albedo, mixing ratios of the selected greenhouse gases, surface temperature, solar sun and zenith angles with different latitude and longitude of the instrument. Finally, the SWupRFsyn estimated from GENSPECT was compared with SWupRFobs from Argus 1000 over a period of four years (2009 and 2013) covering all seasons. We calculate and compare both the synthetic and real measured observed data set. The synthetic model gives SW...

  10. A modern, guano-related occurrence of foggite, CaAl(PO4)(OH)2 · H2O and churchite-(Y), YPO4 · 2H2O in Cioclovina Cave, Romania

    Science.gov (United States)

    Onac, B. P.; Ettinger, K.; Kearns, J.; Balasz, I. I.

    2005-12-01

    This study reports foggite and churchite-(Y) from two spatially separate locations in the guano-related phosphate deposit from the Cioclovina Cave, Romania. Optical microscope observations, powder X-ray diffraction, electron microprobe analyses, and FTIR were used in the analysis of the two minerals. The chemical composition of foggite was determined to be Ca0.925(Al0.91Fe2+0.016)Σ0.926(P0.991Si0.043)Σ1.034O3.74(OH)2.26 · H2O and churchite-(Y) [(Y0.830Dy0.043Er0.033Gd0.029Yb0.022)Σ0.957Ca0.009]P1.023O4.00 · 2H2O. Chemical analyses of Cioclovina churchite-(Y) clearly revealed enrichment in lanthanides of even atomic number. The refined unit-cell parameters are for foggite (orthorhombic) a = 9.264(1) Å, b = 21.334(8) Å, c = 5.197(7) Å, and V = 1027.13(8) Å3 (Z = 8); for churchite-(Y) (monoclinic): a = 5.578(8) Å, b = 15.013(6) Å, c = 6.277(8) Å, β = 117.94(4)°, and V = 464.38(5) Å3 (Z = 4). FTIR spectrum of churchite-(Y) exhibits all the bands assigned to the vibrations of PO4, OH, and water groups.

  11. Synthesis,Crystal Structure and Electrochemical Properties of a One-dimensional Chain Coordination Polymer[Cu(phen)(2,4,6-TMBA)2(H2O)]n

    Institute of Scientific and Technical Information of China (English)

    LI Wei; LI Chang-Hong; YANG Ying-Qun; KUANG Yun-Fei

    2008-01-01

    A one-dimensional chain coordination polymer[Cu(phen)(2,4,6-TMBA)2(H2O)]n has been synthesized by reacting 2,4,6-trimethyl-benzoic acid,1,10-phenanthroline and Cu(Ⅱ)per-chlorate and its structure Was characterized.Crystal data for this complex:tetragonal,space group I41,a=2.0293(3),b=2.0293(3),c=113758(2)nm,a=β=γ=90°,V=5.6657(13)nm3,Dc=1.379g/cm3,Z=8,μ(MoKa)=0.815mm-1,Mr=588.14,F(000)=2456,S=1.047,R=0.0459 and wR=O.1053.The crystal structure shows that two neighboring Cu(Ⅱ)ions are linked together by one bridging-chelating 2,4,6-trimethyl-benzoic group,forming a one-dimensional chain structure.Each Cu(Ⅱ)ion is coordinated with two nitrogen atoms from one 1,10-phenanthroline molecule,three oxygen atoms from three 2,4,6-trimethyl-benzoic acid molecules and one oxygen atom from one water molecule,giving a six-coordinate distorted octahedral coordination geometry.The cyclic voltamrnetry behavior of the complex was also investigated.

  12. X-ray structure of W(CO)3(PPri3)2(H2O)·THF. Isotopic exchange between H2O and η2-D2 ligands and their competitive binding to tungsten

    International Nuclear Information System (INIS)

    Reactions of water with M(CO)3(PR3)2 and M(CO)3(PR3)2(η2-H2) [M = Mo, W; R = Cy (cyclohexyl), i-Pr] have been studied in various organic solvents. Infrared studied of the products showed v(OH) modes at widely varying positions, but no clear evidence for oxidative addition of water was found. The aquo complex W(CO)3(P-i-Pr3)2(H2O)·THF was isolated from THF and structurally characterized. A long W-O distance of 2.32 angstrom was observed for the reversibly bound H2O ligand, which also undergoes hydrogen bonding interactions with both lattice THF and a CO on an adjacent molecule. Water was found to instantaneously displace the dihydrogen ligand in M(CO)3(PR3)2(η2-H2) in THF solution to give aquo complexes, but in hexane H2 remained bound under H2 atmosphere. NMR spectra of the aquo complexes showed rapid exchange between free and coordinated water at 298 K. Isotopic exchange of W(CO)3(P-i-Pr3)2(η2-D2) with H2O under D2 atmosphere took place in THF or toluene giving W(CO)3(P-i-Pr3)2(D2O)

  13. Low-Temperature Heat Capacities and Thermodynamic Properties of Hydrated Nickel L-Threonate Ni(C4H7O5)2·2H2O(s)

    Institute of Scientific and Technical Information of China (English)

    DI You-Ying; TAN Zhi-Cheng; GAO Sheng-Li; CHEN San-Ping; SUN Li-Xian

    2007-01-01

    Low-temperature heat capacities of the compound Ni(C4H7O5)2·2H2O(s) have been measured with an automated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350-369 K. The temperature,enthalpy and entropy of the dehydration were determined to be (368.141+-0.095)K,(18.809+-0.088)kJ·mol-1 and (51.093+-0.239)J·K-1·mol-1 respertively.The exterimental values of the molar heat capacities in the temperature regions of 78-350 and 368-390 K were fitted to two polynomial equations of heat capacities (Cp,m)with the reduced temperatures (X), [X=f(T)], by a least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated on the basis of the fitted polynomials. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated with an interval of 5 K.

  14. Chemistry of borate in salt lake brine (XXXIV)-- Phase diagram of thermodynamic nonequilibrium state of MgO-B2O3-18%MgCl2-H2O system at 20℃

    Institute of Scientific and Technical Information of China (English)

    GAO; Shiyang; (高世扬); ZHU; Lixia; (朱黎霞); HAO; Zhixian; (郝志显); XIA; Shuping; (夏树屏)

    2002-01-01

    The crystallization processes of hydrated Mg-borates, boric, magnesium hydroxide and Mg-oxychloride from MgO-B2O3-18%MgCl2-H2O supersaturated solution at 20℃ have been studied by kinetic method. The crystallization solid phases were characterized by X-ray powder diffraction, IR spectra, thermal analysis and chemical analysis. The liquid-solid phase diagram of thermodynamic nonequilibrium state has been given. In this phase diagram, there exist eight crystallization fields, boric acid(H3BO3), trigomagneborite(MgO*3B2O3*7.5H2O, MgO*3B2O3*7H2O), hungchaoite(MgO*2B2O3*9H2O), inderite(2MgO*3B2O3*15H2O), chloropinnoite(2MgO*2B2O3*MgCl2*14H2O), magnesium hydroxide(Mg(OH)2) and magnesium oxychloride (5Mg(OH)2*MgCl2*8H2O).

  15. Structure and Two-dimensional Correlation Infrared Spectroscopy Study of a New One-dimensional Chain Compound:(4,4'-Hbpy)3[NaMo8O26] (4,4'-bpy)2(H2O)4 (bpy = Bipydine)

    Institute of Scientific and Technical Information of China (English)

    CHEN Yi-Ping; ZHANG Han-Hui; KE Da-Mei; SHEN Xiao-Min; HUANG Chang-Cang; SUN Rui-Qing

    2005-01-01

    A novel compound, (4,4'-Hbpy)3[NaMo8O26](4,4'-bpy)2(H2O)4 1 (bpy = bipydine),was synthesized by the hydrothermal method. Single-crystal X-ray diffraction shows that compound 1 belongs to the monoclinic system, space group C2/m with a = 19.1921(5), b = 18.6931(6), c = 9.3821 (3) (A), β = 104.8020(11)°, V = 3254.22(17) (A)3, C50H51Mo8N10NaO30, Mr = 2062.52, Z = 2,F(000) = 2016,μ = 1.591 mm- 1 and Dc = 2.105 g/cm3. The final R = 0.0283 and wR = 0.0912 for 3118 observed reflections (I > 2σ(Ⅰ)). Compound 1 contains the β-[Mo8O26]4- anion, sodium ion, 4,4'-bpy and lattice crystalline water molecules. The β-[Mo8O26] units link the sodium ion to form a chain structure. The infinitechains of [Na(Mo8O26)]3- blocks are surrounded by protonized 4,4'-bpy cations,4,4'-bpy and lattice crystalline water molecules. The 2D-IR correlation spectroscopy study indicates that the stretching vibrations of Mo=O occur more preferentially due to the thermal effect. The TGA analysis shows that compound 1 has high thermal stability.

  16. Synthesis, Properties and Crystal Structure of a Novel Coordinated Polymer: {(H2en)(H3O)[(BiPb(C2O4)4(H2O)2)]·2(H2O)}n

    Institute of Scientific and Technical Information of China (English)

    GUO Wen-Jun; ZHANG Han-Hui; HUANG Chang-Cang; SUN Rui-Qing; CHEN Yi-Ping; CAO Yan-Ning

    2005-01-01

    A novel oxalate compound {(H2en)(H3O)[BiPb(C2O4)4(H2O)2]·2(H2O)}n 1 (en = ethylenediamine) containing lead and bismuth has been synthesized by hydrothermal methods, and structurally characterized by X-ray single-crystal diffraction. It crystallizes in monoclinic, space group P21/c with a = 11.6160(1), b = 12.7426(1), c = 15.5683(5) (A), β = 108.442(4)°, BiPbC10N2O21H21, Mr = 921.46, V = 2186.0(4) (A)3, Z = 4, Dc = 2.800 g/cm3, F(000) = 1712 and μ(MoKα) = 15.837 mm-1. The final R = 0.0502 and wR = 0.1261 for 3391 observed reflections with I > 2(σI). The title com- pound consists of 2-D polyanions and protonized organic amine cations, and they are combined to each other by static attractive force and H-bonds to form the so-called organic-inorganic hybrid material.

  17. Bulk modulus of basic sodalite, Na8[AlSiO4]6(OH)2·2H2O, a possible zeolitic precursor in coal-fly-ash-based geopolymers

    KAUST Repository

    Oh, Jae Eun

    2011-01-01

    Synthetic basic sodalite, Na8[AlSiO4] 6(OH)2•2H2O, cubic, P43n, (also known as hydroxysodalite hydrate) was prepared by the alkaline activation of amorphous aluminosilicate glass, obtained from the phase separation of Class F fly ash. The sample was subjected to a process similar to geopolymerization, using high concentrations of a NaOH solution at 90 °C for 24 hours. Basic sodalite was chosen as a representative analogue of the zeolite precursor existing in Na-based Class F fly ash geopolymers. To determine its bulk modulus, high-pressure synchrotron X-ray powder diffraction was applied using a diamond anvil cell (DAC) up to a pressure of 4.5 GPa. A curve-fit with a truncated third-order Birch-Murnaghan equation of state with a fixed K\\'o = 4 to pressure-normalized volume data yielded the isothermal bulk modulus, K o = 43 ± 4 GPa, indicating that basic sodalite is more compressible than sodalite, possibly due to a difference in interactions between the framework host and the guest molecules. © 2010 Elsevier Ltd.

  18. 草酸根桥联的双核铜(Ⅱ)配合物[Cu2(phen)2(H2O)2(μ2-C2O4)](NO3)2的合成及晶体结构%Synthesis and Crystal Structure of Oxalato-bridged Binuclear Copper(Ⅱ) Complex [Cu2(phen)2(H2O)2(μ2-C2O4)](NO3)2

    Institute of Scientific and Technical Information of China (English)

    卢文贯; 潘育方; 彭翠红

    2005-01-01

    A new binuclear copper(Ⅱ) complex, [Cu2(phen)2(H2O)2(μ2-C2O4)](NO3)2, has been synthesized and characterized by elemental analysis, IR and UV-Vis spectrum. Its crystal structure was determined by single crystal X-ray diffraction techniques. Crystal data: monoclinic, space group P21/c, α=0.71221(8)nm, b=1.17093(14)nm,c=1.7837(2)nm, β=111.828(2)°, and V=1.3808(3)nm3, Dc=1.769Mg·m-3, Z=2, F(000)=744, R1=0.0254, ωR2=0.0695, Gof=l.077, △ρ=328~-455e·nm-3. The complex is packed by one centrosymmetry binuclear copper(Ⅱ) unit, oxalate dianion and NO3- anion. In the molecule structure of the title complex, two Cu(Ⅱ) ions are bridged by oxalate dianion and each Cu(Ⅱ) ions coordinates with two nitrogen atoms from 1,10-phenanthroline ligand and one oxygen atom from water to form a five-coordinate distorted square-pyramidal configuration. The hydrogen bonds are observed between coordinated water molecules and NO3- anions. The analysis of the crystal structure indicates that the complex has a two-dimensional stacking network structure, which is formed by intramolecular hydrogen bonds, intermolecular hydrogen bonds and stacking effect of aromatic ring. CCDC: 255345.

  19. A novel amido-pyrophosphate Mn(II) chelate complex with the synthetic ligand O{P(O)[NHC(CH3)3]2}2 (L): [Mn(L)2{OC(H)N(CH3)2}2]Cl2·2H2O.

    Science.gov (United States)

    Tarahhomi, Atekeh; Pourayoubi, Mehrdad; Fejfarová, Karla; Dušek, Michal

    2013-03-01

    The title complex, trans-bis(dimethylformamide-κO)bis{N,N'-N'',N'''-tetra-tert-butyl[oxybis(phosphonic diamide-κO)]}manganese(II) dichloride dihydrate, [Mn(C16H40N4O3P2)2(C3H7NO)2]Cl2·2H2O, is the first example of a bis-chelate amido-pyrophosphate (pyrophosphoramide) complex containing an O[P(O)(NH)2]2 fragment. Its asymmetric unit contains half of the complex dication, one chloride anion and one water molecule. The Mn(II) atom, located on an inversion centre, is octahedrally coordinated, with a slight elongation towards the monodentate dimethylformamide ligand. Structural features of the title complex, such as the P=O bond lengths and the planarity of the chelate ring, are compared with those of previously reported complexes with six-membered chelates involving the fragments C(O)NHP(O), (X)NP(O) [X = C(O), C(S), S(O)2 and P(O)] and O[P(O)(N)2]2. This analysis shows that the six-membered chelate rings are less puckered in pyrophosphoramide complexes containing a P(O)OP(O) skeleton, such as the title compound. The extended structure of the title complex involves a linear aggregate mediated by N-H...O and N-H...Cl hydrogen bonds, in which the chloride anion is an acceptor in two additional O-H...Cl hydrogen bonds. PMID:23459342

  20. Preparation, crystal structure, and characterization of an inorganic-organic hybrid polyoxoniobate [Cu(en)2]3[Cu(en)2(H2O)]1.5[K0.5Nb24O72H14.5]2.25H2O

    Indian Academy of Sciences (India)

    Jing-Ping Wang; Hong-Yu Niu; Jing-Yang Niu

    2008-05-01

    An inorganic-organic hybrid polyoxoniobate compound [Cu(en)2]3[Cu(en)2(H2O)]1.5 [K0.5Nb24O72H14.5]2.25H2O (1) was synthesized by reaction of K7HNb6O19.13H2O, Cu(CH3COOH)2.H2O and en (ethylenediamine) in aqueous solution and characterized by IR, ESR spectroscopy and singlecrystal X-ray diffraction method. Structure analysis indicates that compound 1 consists of a new type polyoxoniobate anion [K0.5Nb24O72H14.5]9-, three [Cu(en)2]2+, one point five [Cu(en)2(H2O)]2+, and two point two five crystal water molecules. The structure contains N-H$\\cdots$O hydrogen bonds between the coordinated ethylenediamine and the polyniobate-anion. The whole molecule possesses the 3 symmetry.

  1. Heat capacities and entropies from 8 to 1000 K of langbeinite (K2Mg2(SO4)3), anhydrite (CaSO4) and of gypsum (CaSO4·2H2O)

    Science.gov (United States)

    Robie, Richard A.; Russell-Robinson, Susan; Hemingway, Bruce S.

    1989-01-01

    Heat capacities of K2Mg2(SO4)3 (langbeinite) and CaSO4 (anhydrite) were measured from approximately 8 to 1000 K by combined adiabatic shield calorimetry (8-365 K) and differential scanning calorimetry (350-1000 K). Heat capacities were also measured on natural crystals of gypsum (CaSO4 · 2H2O) between 8.1 and 323.5 K. The molar entropies at 298.15 K, Smo(298.15 K), are 378.8 ± 0.6, 107.4 ± 0.2 and 193.8 ± 0.3 J K−1 mol−1 for langbeinite, anhydrite and gypsum, respectively. The heat capacity in J K−1 mol−1 of langbeinite can be represented by the equation Cp,mo(K2Mg2(SO4)3T) = 535.9 + 0.11011T-1.0200 × 106/T2-4.909 × 10−5T2 -4040.2/T0.5 between 300 and 1000 K with an average deviation of ± 0.4%. For anhydrite the heat capacity between 300 and 1000 K is given by Cp,mo(CaSO4,T) = 372.8 - 0.1574 T +1.695 × 106/T2 + 7.993 × 10−5T2 - 4330.8/T0.5 with an average deviation of ±0.4%.

  2. Synthesis and Crystal Structure of Copper (Ⅱ) Compound with 3,3'-Azobispyridine Ligand[Cu(NO3)2(H2O)2(3,3'-azpy)2

    Institute of Scientific and Technical Information of China (English)

    李宝龙; 郎建平; 王寿武; 徐正; 陈久桐

    2003-01-01

    The title complex [Cu(NO3)2(H2O)2(3,3'-azpy)2] (3,3'-azpy = 3,3'-azobispyridine) has been synthesized and characterized, and its crystal belongs to the triclinic system, space group P ī with the following crystallographic parameters: a = 7.4161(2), b = 8.1754(3), c = 10.7545(4) A。,α= 92.958(2),β= 109.978(1),γ = 93.369(2)°, V = 609.96(4) A。3, C20H20N10CuO8, Mr = 592.00, Dc = 1.612 g/cm3, μ(MoKα)= 0.964 mm-1, F(000) = 303, Z = 1, the final R = 0.0494 and wR = 0.1269 for 1945 observed reflections (I > 2((I)). X-ray analysis reveals that the Cu atom adopts a distorted octahedral (4 + 2) coordination. The four closer donor atoms include two N atoms of 3,3'-azpy and two Oatoms of the coordination aqua with the Cu-N and Cu-O distances of 2.014(3) and 1.974(3)A。, respectively. Two longer out-of-plane Cu-O bonds (2.450(3) A。) from nitrate complete the strongly distorted octahedral coordination of the Cu atom. Hydrogen bonds are formed through H atoms of each coordination aqua with the remaining N atoms of 3,3'-azpy and O atoms of nitrate. A two-dimensional network is constructed by hydrogen bonds and π-π interactions.

  3. Synthesis and Crystal Structure of a Two-dimensional Silver(I)-Iron(III) Heteronuclear Coordination Polymer:{[Ag4Fe2(SCN)12(H2O)2] [(inaH)2(H2O)2]}n

    Institute of Scientific and Technical Information of China (English)

    LI,Xiu-Ling(李秀玲); TONG,Ming-Liang(童明良); NIU,De-Zhong(牛德仲); CHEN,Jiu-Tong(陈久桐)

    2004-01-01

    The 2-D heteronuclear coordination polymer {[Ag4Fe2(SCN)12(H2O)2] [(inaH)2(H2O)2]}n (1) (inaH is the abbreviation of protonated isonicotinic acid) with chemical formula C24H20Ag4Fe2N14O8S12 has been synthesized and characterized by single crystal X-ray diffraction, elemental analysis and IR spectroscopy. The Ag2S2 rings connect two kinds of octahedral geometries of Fe(III) ions, [Fe(NCS)6]3- and [Fe(H2O)2(NCS)4]- units with bridging thiocyanate ions leading to 2-D [Ag4Fe2(SCN)12(H2O)2]2- anion framework. Four kinds of rings including the unprecedented thirty-two membered Ag4Fe4(SCN)8 rings share corners or edges in the 2-D anion layer structure. All thiocyanates coordinate to the metal ions according to the HSAB principle with N atoms binding to the Fe(III) ions and with S atoms binding to Ag(I) ions. Pronoated ina cations stabilize the layer structure as counter ions and hydrogen bonds were formed within the pronoated ina cations dimer and between the dimers and the lattice waters. Crystal data: Mr=1560.44, triclinic, P(1-) a=0.76082(1) nm, b=0.9234 nm, c=1.85611(4) nm, α=103.0170(10)°, β=93.7780(10)°, γ=97.4080(10), V=1.25385(3) nm3, Z=1, μ(Mo Kα)=2.650 mm-1, Dc=2.067 g·cm-3, F(000)=758, R1=0.0412, wR2=0.1003.

  4. Observation of the novel "three-pointed star" cage-like (H2O)5 cluster in a polymeric solid {[Ag2(bpp)2(H2O)2](chd)·9H2O}n%固态配位聚合物{[Ag2(bpp)2(H2O)2](chd)·9H2O}n中之新颖“三叉星”笼状(H2O)5水簇的发现

    Institute of Scientific and Technical Information of China (English)

    骆耿耿; 熊红波; 傅志勇; 戴劲草

    2012-01-01

    固态配位聚合物{[Ag2(bpp)2(H2O)2](chd)·9H2O}n(1) (bpp=1,3-二(4-吡啶基)丙烷、H2chd=1,4-环己烷二羧酸)是通过溶液相超声波合成技术获得的,建立在X射线结构分析技术基础上的结构(单斜晶系C2/c空间群,Z=4;晶胞参数a=30.37(2)(A),b=9.271(5)(A),c=18.89(1)(A);β=128.47°;V=4164(4)(A)3)展现出该化合物捕捉了一条有趣的、由“三叉星”笼状五聚体及D2h构型四聚体水簇交替构成的一维水带,该化合物之所以新奇在于其代表了被认为是不太稳定的笼状水五聚体团簇的晶体学范例.第一性原理的密度涵理论(DFT)计算表明,笼状五聚体及D2h构型四聚体水簇的相互连接对于此类欠稳定水簇的稳定性是有益的.%Coordination polymeric solid, {[Ag2(bpp)2(H2O)2](chd)-9H2O}n (1) (bpp = 1,3-bis(4-pyridyl) propane, H2chd = 1,4-cyclo- hexanedicarboxylic acid), has been obtained by the solution phase ultrasonic synthesis techniques. The structure established through X-ray structural analysis shows that the compound traps an interesting ID water tape built by the alternating "three-pointed star" cage-like pentameric and D2h tetrameric clusters (C2/c, Z = 4; a = 30.37(2) A, b = 9.271(5) A, and c = 18.89(1) (A); β = 128.47°; V = 4164(4) (A)3). The novelty of the present complex is the rarely crystallographic example of the cage-shaped water pentamer, which is usually ascribed to a less-stable species. A first-principle density functional theory (DFT) calculation demonstrates that the interconnectivity between cage-like pentamers and D2h, tetramers is beneficial for contribution to the structural stabilization of these less-stable water cluster species.

  5. Hydrothermal Synthesis, Structure and Bioactivity of Lamellar Cu (DMBC) 2 (H2O) 2(DMBC :2-(3,5-Dimethylphenoxy) acetic Acid) Complex%Cu(DMBC)2(H2O)2(DMBC:3,5-二甲基苯氧基乙酸)配合物层状超分子的水热合成、结构及生物活性

    Institute of Scientific and Technical Information of China (English)

    张有明; 谢永强; 姚虹; 耿志远; 刘江龙; 贺晓旋; 魏太保

    2013-01-01

    用聚乙二醇400为相转移催化剂,由3,5-二甲基苯酚和氯乙酸合成了3,5-二甲基苯氧基乙酸(DMBC),用水热法将它与氯化铜合成了配合物Cu(DMBC)2(H2O)2,通过元素分析、红外光谱对其进行了表征;采用X射线单晶衍射法测定了其晶体和分子结构.其晶体属单斜晶系,P21/c空间群.晶胞参数:a=1.526(2) nm,b=0.7092(11) num,c=1.0942(17) nm,β=104.567(15)°,V=1.146(3) nm3,Z=2,F(000) =478.在分子中,Cu(Ⅱ)分别与2个配体的羧基氧原子和2个水分子配位,中心离子构成稍微变形的平面四边形配位构型.分之间通过氢键和π-π相互作用自组装成稳定的二维层状超分子.利用Gauss03程序,在B3LYP/6-31G水平上对标题化合物进行了量化计算,给出了配合物分子中各原子的净电荷布居,计算结果与测定结果吻合.测试了该配合物对油菜籽发芽生长促进活性和抑菌作用.CCDC:909139%One lamellar coordination compound,Cu(DMBC)2 (H2O)2 (DMBC =2-(3,5-dimethylphenoxy)acetic acid),was hydrothermally synthesized using CuCl2 and 2-(3,5-dimethylphenoxy) acetic acid (DMBC).The ligand,DMBC,was obtained by the reaction of 3,5-dimethylphenol with 2-chloroacetic acid using polyethylene glycol(PEG-400) as the phase transfer catalyst.The compound was characterized by elemental analysis,IR and single crystal X-ray diffraction.The title compound crystallizes in the monoclinic system with space group P21/c,a =1.526 (2) nm,b =0.7092 (11) nm,c =1.0942 (17) nm,β =104.567 (15) °,V =1.146(3) nm3,Z =2,F(000) =478.The centric Cu (Ⅱ) cation situates in the center of a slightly deformed quadrilateral plane and coordinated with two oxygen atoms from two ligands and two water molecules.It further self-assembles into a 2D lamellar supramolecular frameworks via π-π interactions and hydrogen bondings.A quantization calculation of the title compound was carried out at the B3LYP/6-31G level using Gussian 03 program,and the atomic charge distribution within

  6. Electronic structure of the water oxidation catalyst cis,cis-[(bpy)2(H2O)Ru(III)ORu(III)(OH2)(bpy)2]4+, the blue dimer.

    Science.gov (United States)

    Jurss, Jonah W; Concepcion, Javier J; Butler, Jennifer M; Omberg, Kristin M; Baraldo, Luis M; Thompson, Darla Graff; Lebeau, Estelle L; Hornstein, Brooks; Schoonover, Jon R; Jude, Hershel; Thompson, Joe D; Dattelbaum, Dana M; Rocha, Reginaldo C; Templeton, Joseph L; Meyer, Thomas J

    2012-02-01

    The first designed molecular catalyst for water oxidation is the "blue dimer", cis,cis-[(bpy)(2)(H(2)O)Ru(III)ORu(III)(OH(2))(bpy)(2)](4+). Although there is experimental evidence for extensive electronic coupling across the μ-oxo bridge, results of earlier DFT and CASSCF calculations provide a model with magnetic interactions of weak to moderately coupled Ru(III) ions across the μ-oxo bridge. We present the results of a comprehensive experimental investigation, combined with DFT calculations. The experiments demonstrate both that there is strong electronic coupling in the blue dimer and that its effects are profound. Experimental evidence has been obtained from molecular structures and key bond distances by XRD, electrochemically measured comproportionation constants for mixed-valence equilibria, temperature-dependent magnetism, chemical properties (solvent exchange, redox potentials, and pK(a) values), XPS binding energies, analysis of excitation-dependent resonance Raman profiles, and DFT analysis of electronic absorption spectra. The spectrum can be assigned based on a singlet ground state with specific hydrogen-bonding interactions with solvent molecules included. The results are in good agreement with available experimental data. The DFT analysis provides assignments for characteristic absorption bands in the near-IR and visible regions. Bridge-based dπ → dπ* and interconfiguration transitions at Ru(III) appear in the near-IR and MLCT and LMCT transitions in the visible. Reasonable values are also provided by DFT analysis for experimentally observed bond distances and redox potentials. The observed temperature-dependent magnetism of the blue dimer is consistent with a delocalized, diamagnetic singlet state (dπ(1)*)(2) with a low-lying, paramagnetic triplet state (dπ(1)*)(1)(dπ(2)*)(1). Systematic structural-magnetic-IR correlations are observed between ν(sym)(RuORu) and ν(asym)(RuORu) vibrational energies and magnetic properties in a series of

  7. Nevadaite, (Cu2+, Al, V3+)6 [Al8 (PO4)8 F8] (OH 2 (H2O)22, a new phosphate mineral species from the Gold Quarry mine, Carlin, Eureka County, Nevada: description and crystal structure

    Science.gov (United States)

    Cooper, M.A.; Hawthorne, F.C.; Roberts, Andrew C.; Foord, E.E.; Erd, Richard C.; Evans, H.T., Jr.; Jensen, M.C.

    2004-01-01

    Nevadaite, (Cu2+, ???, Al, V3+)6 (PO4)8 F8 (OH)2 (H2O)22, is a new supergene mineral species from the Gold Quarry mine, near Carlin, Eureka County, Nevada, U.S.A. Nevadaite forms radiating clusters to 1 mm of prismatic crystals, locally covering surfaces more that 2 cm across; individual crystals are elongate on [001] with a length:width ratio of > 10:1 and a maximum diameter of ???30 ??m. It also occurs as spherules and druses associated with colorless to purple-black fluellite, colorless wavellite, strengitevariscite, acicular maroon-to-red hewettite, and rare anatase, kazakhstanite, tinticite, leucophosphite, torbernite and tyuyamunite. Nevadaite is pale green to turquoise blue with a pale powder-blue streak and a vitreous luster; it does not fluoresce under ultra-violet light. It has no cleavage, a Mohs hardness of ???3, is brittle with a conchoidal fracture, and has measured and calculated densities of 2.54 and 2.55 g/cm3, respectively. Nevadaite is biaxial negative, with ?? 1.540, ?? 1.548, ?? 1.553, 2V(obs.) = 76??, 2V(calc.) = 76??, pleochroic with X pale greenish blue, Y very pale greenish blue, Z blue, and with absorption Z ??? X > Y and orientation X = c, Y = a, Z = b. Nevadaite is orthorhombic, space group P21mn, a 12.123(2), b 18.999(2), c 4.961(1) A?? , V 1142.8(2) A??3, Z = 1, a:b:c = 0.6391:1:0.2611. The strongest seven lines in the X-ray powder-diffraction pattern [d in A??(I)(hkl)] are: 6.077(10)(200), 5.618(9)(130), 9.535(8)(020), 2.983(6)(241), 3.430(4)(041), 2.661(4)(061 , and 1.844(4)(352). A chemical analysis with an electron microprobe gave P2O5 32.54, Al2O3 27.07, V2O3 4.24, Fe2O3 0.07, CuO 9.24, ZnO 0.11, F 9.22, H2O (calc.) 23.48, OH ??? F -3.88, sum 102.09 wt.%; the valence states of V and Fe, and the amount of H2O, were determined by crystal-structure analysis. The resulting empirical formula on the basis of 63.65 anions (including 21.65 H2O pfu) is (CU2+2.00 Zn0.02 V3+0.98 Fe3+0.01 Al1.15)??4.16 Al8 P7.90 O32 [F8.37 (OH 1.63]??10 (H2O

  8. Syntheses and Structural Researches of Yb3+ Complexes with Nitrilotriacetic Acids--Nine-coordinate K3[Yb(nta)2(H2O)]·5H2O and Eight-coordinate Na3[Yb(nta)2]·6H2O Complexes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Yb3+ complexes with two nitrilotriacetic acid molecules were prepared and their compositions were determined as K3[Yb(nta)2(H2O)]*5H2O and Na3[Yb(nta)2]*6H2O by elemental analyses. Their structures were characterized by single-crystal X-ray diffraction analyses. In complex K3[Yb(nta)2(H2O)]*5H2O, the YbN2O7 part forms a nine-coordinate monocapped square antiprismatic structure. In complex Na3[Yb(nta)2]*6H2O, the YbN2O6 part forms an eight-coordinate square antiprismatic structure. It can be seen that the outer cations (K+ and Na+) greatly affect the coordination number and coordinate structure from these results.

  9. Interaction of [Rh2(O2CCH3)4(H2O)2] and [Rh2(O2CCH(OH)Ph)2(phen)2(H2O)2](O2C-CH(OH)Ph)2 With Sulfhydryl Compounds and Ceruloplasmin

    OpenAIRE

    Jakimowicz, Piotr; Ostropolska, Lucja; Pruchnik, Florian P.

    2000-01-01

    The interaction of binuclear rhodium(II) complexes [Rh2(OOCCH3)4(H2O)2], [Rh2{OOCCH(OH)Ph}2(phen)2(H2O)2] {OOCCH(OH)Ph}2, [Rh2(OOCCH3)2(bpy)2(H2O)2](OOCCH3)2 and [Rh2Cl2(OOCMe)2(bpy)2](3H2O) with ceruloplasmin, cysteine, glutathione and coenzyme A have been investigated using. UV-Vis and CD spectroscopies. The complexes containing phen or bpy at pH = 7.4 and 4.0 are readily reduced with sulfhydryl compounds, while rhodium(II) acetate is relatively stable in these conditions. Complex [Rh2{OOCC...

  10. Batievaite-(Y), Y2Ca2Ti[Si2O7]2(OH)2(H2O)4, a new mineral from nepheline syenite pegmatite in the Sakharjok massif, Kola Peninsula, Russia

    Science.gov (United States)

    Lyalina, L. M.; Zolotarev, A. A.; Selivanova, E. A.; Savchenko, Ye. E.; Krivovichev, S. V.; Mikhailova, Yu. A.; Kadyrova, G. I.; Zozulya, D. R.

    2016-05-01

    Batievaite-(Y), Y2Ca2Ti[Si2O7]2(OH)2(H2O)4, is a new mineral found in nepheline syenite pegmatite in the Sakharjok alkaline massif, Western Keivy, Kola Peninsula, Russia. The pegmatite mainly consists of nepheline, albite, alkali pyroxenes, amphiboles, biotite and zeolites. Batievaite-(Y) is a late-pegmatitic or hydrothermal mineral associated with meliphanite, fluorite, calcite, zircon, britholite-group minerals, leucophanite, gadolinite-subgroup minerals, titanite, smectites, pyrochlore-group minerals, zirkelite, cerianite-(Ce), rutile, behoite, ilmenite, apatite-group minerals, mimetite, molybdenite, and nickeline. Batievaite-(Y) is pale-cream coloured with white streak and dull, greasy or pearly luster. Its Mohs hardness is 5-5.5. No cleavage or parting was observed. The measured density is 3.45(5) g/cm3. Batievaite-(Y) is optically biaxial positive, α 1.745(5), β 1.747(5), γ 1.752(5) (λ 589 nm), 2V meas. = 60(5)°, 2V calc. = 65°. Batievaite-(Y) is triclinic, space group P-1, a 9.4024(8), b 5.5623(5), c 7.3784(6) Å, α 89.919(2), β 101.408(2), γ 96.621(2)°, V 375.65(6) Å3 and Z = 1. The eight strongest lines of the X-ray powder diffraction pattern [d(Å)(I)(hkl)] are: 2.991(100)(11-2), 7.238(36)(00-1), 3.061(30)(300), 4.350(23)(0-1-1), 9.145(17)(100), 4.042(16)(11-1), 2.819(16)(3-10), 3.745(13)(2-10). The chemical composition determined by electron probe microanalysis (EPMA) is (wt.%): Nb2O5 2.25, TiO2 8.01, ZrO2 2.72, SiO2 29.96, Al2O3 0.56, Fe2O3 0.43, Y2O3 11.45, La2O3 0.22, Ce2O3 0.33, Nd2O3 0.02, Gd2O3 0.07, Dy2O3 0.47, Er2O3 1.07, Tm2O3 0.25, Yb2O3 2.81, Lu2O3 0.45, CaO 24.98, MnO 1.31, MgO 0.01, Na2O 1.13, K2O 0.02, F 2.88, Cl 0.19, H2O 6.75 (determined on the basis of crystal structure data), O = (F,Cl) -1.25, total 97.09 wt.%. The empirical formula based on the EPMA and single-crystal structure analyses is (Y0.81Ca0.65Mn0.15Zr0.12Yb0.11Er0.04Fe3+ 0.04Ce0.02Dy0.02Lu0.02La0.01Tm0.01)Σ2.00((H2O)0.75Ca0.70□0.55)Σ2.00Ca2.00(□0.61Na0.25( H2O

  11. Ferroelectric TGS ((NH sub 2 CH sub 2 COOH) sub 3 centre dot H sub 2 SO sub 4) under high pressure

    CERN Document Server

    Kobayashi, Y; Furuta, H; Endo, S; Deguchi, K

    2002-01-01

    The ferroelectric transition temperature T sub c of (NH sub 2 CH sub 2 COOH) sub 3 centre dot H sub 2 SO sub 4 (TGS), which is a typical order-disorder-type ferroelectric, was determined by dielectric constant and Raman scattering measurements under high pressure. T sub c increased, passed through a maximum and then decreased slightly with increasing pressure, and then abruptly dropped at about 2.5 GPa, where a transition to a new high-pressure phase was confirmed to exist. A tentative p-T phase diagram was proposed for TGS.

  12. Activation of silicon quantum dots and coupling between the active centre and the defect state of the photonic crystal in a nanolaser

    Institute of Scientific and Technical Information of China (English)

    Huang Wei-Qi; Chen Hang-Qiong; Shu Qin; Liu Shi-Rong; Qin Chao-Jian

    2012-01-01

    A new nanolaser concept using silicon quantum dots (QDs) is proposed.The conduction band opened by the quantum confinement effect gives the pumping levels.Localized states in the gap due to some surface bonds on Si QDs can be formed for the activation of emission.An inversion of population can be generated between the localized states and the valence band in a QD fabricated by using a nanosecond pulse laser.Coupling between the active centres formed by localized states and the defect states of the two-dimensional (2D) photonic crystal can be used to select the model in the nanolaser.

  13. Vibrational investigations of CO2-H2O, CO2-(H2O)2, and (CO2)2-H2O complexes isolated in solid neon.

    Science.gov (United States)

    Soulard, P; Tremblay, B

    2015-12-14

    The van der Waals complex of H2O with CO2 has attracted considerable theoretical interest as a typical example of a weak binding complex with a dissociation energy less than 3 kcal/mol. Up to now, experimental vibrational data are sparse. We have studied by FTIR the complexes involving CO2 and water molecules in solid neon. Many new absorption bands close to the well known monomers fundamentals give evidence for at least three (CO2)n-(H2O)m complexes, noted n:m. Concentration effects combined with a detailed vibrational analysis allow for the identification of sixteen, twelve, and five transitions for the 1:1, 1:2, and 2:1 complexes, respectively. Careful examination of the far infrared spectral region allows the assignment of several 1:1 and 1:2 intermolecular modes, confirmed by the observation of combinations of intra + intermolecular transitions, and anharmonic coupling constants have been derived. Our results demonstrate the high sensibility of the solid neon isolation to investigate the hydrogen-bonded complexes in contrast with the gas phase experiments for which two quanta transitions cannot be easily observed.

  14. Vibrational investigations of CO2-H2O, CO2-(H2O)2, and (CO2)2-H2O complexes isolated in solid neon

    Science.gov (United States)

    Soulard, P.; Tremblay, B.

    2015-12-01

    The van der Waals complex of H2O with CO2 has attracted considerable theoretical interest as a typical example of a weak binding complex with a dissociation energy less than 3 kcal/mol. Up to now, experimental vibrational data are sparse. We have studied by FTIR the complexes involving CO2 and water molecules in solid neon. Many new absorption bands close to the well known monomers fundamentals give evidence for at least three (CO2)n-(H2O)m complexes, noted n:m. Concentration effects combined with a detailed vibrational analysis allow for the identification of sixteen, twelve, and five transitions for the 1:1, 1:2, and 2:1 complexes, respectively. Careful examination of the far infrared spectral region allows the assignment of several 1:1 and 1:2 intermolecular modes, confirmed by the observation of combinations of intra + intermolecular transitions, and anharmonic coupling constants have been derived. Our results demonstrate the high sensibility of the solid neon isolation to investigate the hydrogen-bonded complexes in contrast with the gas phase experiments for which two quanta transitions cannot be easily observed.

  15. Synthesis,Crystal Structure,Thermal Decomposition and Sensitivity Properties of [Zn(AZT)4(H2O)2](PA)2·4H2O and [Zn(AZT)2(H2O)4](HTNR)2·4H2O

    Institute of Scientific and Technical Information of China (English)

    CUI Yan; ZHANG Tong-Lai; ZHANG Jian-Guo; YANG Li

    2008-01-01

    Two new coordination compounds [Zn(AZT)4(H2O)2](PA)2·4H2O and [Zn(AZT)2(H2O)4](HTNR)2·4H2O have been prepared by using AZT(3-azido-1,2,4-triazole)as ligands,PA-(picrate)or HTNR-(anion formed by the deprotonation of one of the two hydroxyl-groups of 2,4,6-trinitroresorcinol)as outer anions.The X-ray crystallographic data show that the central zinc(Ⅱ)ion is coordinated by four N atoms of four AZT molecules and two O atoms of two H2O molecules in [Zn(AZT)4(H2O)2](PA)2·4H2O.In [Zn(AZT)2(H2O)4](HTNR)2·4H2O,six coordination-atoms come from two N atoms of two AZT molecules and four O atoms of four H2O molecules.The coordina-tion sites of AZT ligands in both compounds are always 4-N atoms of the triazole rings.H2O molecules play vital roles in the formation of hydrogen bonds,which contribute to the construction of the crystal structures of both compounds.The offset face-to-face π-π stacking interactions existing in the crystal of [Zn(AZT)4(H2O)2](PA)2·4H2O also contribute to the formation and stability of its crystal structure.TG-DTG and DSC analysis results show that the thermal decomposition processes of [Zn(AZT)2(H2O)4](HTNR)2·4H2O are milder than those of [Zn-(AZT)4(H2O)2](PA)2·4H2O due to the more coordination H2O molecules and less AZT ligands in the molecular unit of the former compound.Sensitivity tests reveal that [Zn(AZT)4(H2O)2](PA)2·4H2O has sensitive nature towards heat,whereas [Zn(AZT)2(H2O)4](HTNR)2·4H2O is insensitive;both compounds are insensitive to friction and im-pact.

  16. Novel example of stabilization of the BF3·H2O aquo complex in the [(BF3·H2O)2·18-crown-6·2H2O] compound of the 'guest-host' type

    International Nuclear Information System (INIS)

    [(BF3·H2O)2·18-crown-6·2H2O] complex synthesized by interaction BF3·(C2H5)2O with 18-crown-6 in the presence of moisture. The complex was identified using methods of 1H NMR, vibrational spectroscopy, thermogravimetry, X-ray diffraction analysis. The complex is crystallized in triclinic syngony: a = 7.250(1), b = 8.256(2), c = 10.346(1) A, α = 93.88(1), β = 108.61(2), γ = 111.40(2) deg, Z = 1, sp. gr. P1.14 refs., 3 figs., 1 tab

  17. Competition of the Peierls relief and structural defects in damping the domain walls in [Mn left brace (R/S)-pn right brace]2[Mn left brace(R/S)-pn right brace2(H2O)][Cr(CN)6]2 ferrimagnet

    International Nuclear Information System (INIS)

    The [ [Mn left brace (R/S)-pn right brace]2[Mn left brace(R/S)-pn right brace2(H2O)][Cr(CN)6]2 molecular ferrimagnet exhibits an inverse sequence of changes in the domain wall motion regimes with increasing temperature in alternative magnetic field of 0.04-1400 Hz frequency. Initiation of the relaxation regime on the background of creep indicates that there are two different systems of the domain walls damping. The threshold amplitude of the alternative magnetic field corresponds to the Peierls relief contribution to the domain wall dynamics as well as the defect contribution usually considered.

  18. Synthesis, Characterization and Crystal Structure of an Inorganic-organic Composite Metatungstate: [Co(4,4'-bipy)2(H2O)4](4,4'-H2bipy)2[H2W12O40]·5.5H2O

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel hybrid compound [Co(4,4'-bipy)2(H2O)4](4,4'- H2bipy)2[H2W12O40]·5.5H2Ohas been synthesized from an acidified aqueous solution and characterized by elemental and thermal analyses, IR and UV spectroscopy, and single-crystal X-ray structure determination. Structure analysis indicates that the title compound is of monoclinic, space group C2/c, with a = 21.315(9), b = 15.303 (7), c = 24.139(10) (A), β = 105.170(5)o, V = 7599(6) (A)3, Mr = 3706.99, Z = 4, F(000) = 6616, Dc = 3.231, μ = 18.395 mm-1, R = 0.0652 and wR = 0.1594. X-ray crystallographic study shows that the title compound consists of one [Co(4,4'-bipy)2(H2O)4]2+ cation, two diprotonated 4,4'-bipyridine molecules, 5.5 water molecules of crystallization, and one metatungstate polyoxoanion [H2W12O40]6-, which approaches an effective Td point symmetry. TG-DTA analysis indicates that the framework of the metatungstate polyoxoanion is collapsed at 587.0 ℃.

  19. Degradation of 5-FU by means of advanced (photo)oxidation processes: UV/H2O2, UV/Fe2+/H2O2 and UV/TiO2 — Comparison of transformation products, ready biodegradability and toxicity

    International Nuclear Information System (INIS)

    The present study investigates the degradation of the antimetabolite 5-fluorouracil (5-FU) by three different advanced photo oxidation processes: UV/H2O2, UV/Fe2+/H2O2 and UV/TiO2. Prescreening experiments varying the H2O2 and TiO2 concentrations were performed in order to set the best catalyst concentrations in the UV/H2O2 and UV/TiO2 experiments, whereas the UV/Fe2+/H2O2 process was optimized varying the pH, Fe2+ and H2O2 concentrations by means of the Box–Behnken design (BBD). 5-FU was quickly removed in all the irradiation experiments. The UV/Fe2+/H2O2 and UV/TiO2 processes achieved the highest degree of mineralization, whereas the lowest one resulted from the UV/H2O2 treatment. Six transformation products were formed during the advanced (photo)oxidation processes and identified using low and high resolution mass spectrometry. Most of them were formed and further eliminated during the reactions. The parent compound of 5-FU was not biodegraded, whereas the photolytic mixture formed in the UV/H2O2 treatment after 256 min showed a noticeable improvement of the biodegradability in the closed bottle test (CBT) and was nontoxic towards Vibrio fischeri. In silico predictions showed positive alerts for mutagenic and genotoxic effects of 5-FU. In contrast, several of the transformation products (TPs) generated along the processes did not provide indications for mutagenic or genotoxic activity. One exception was TP with m/z 146 with positive alerts in several models of bacterial mutagenicity which could demand further experimental testing. Results demonstrate that advanced treatment can eliminate parent compounds and its toxicity. However, transformation products formed can still be toxic. Therefore toxicity screening after advanced treatment is recommendable. - Highlights: • Full primary elimination of 5-FU was achieved in all the treatments. • None of the processes were able to fully mineralize 5-FU. • Six transformation products (TPs) were identified during

  20. Syntheses and Structural Researches of Nine-coordinate K3[TbIII(nta)2(H2O)]·5.5H2O and Eight-coordinate K3[YbIII(nta)2]·5H2O

    Institute of Scientific and Technical Information of China (English)

    王君; 张向东; 王钰; 张扬; 张朝红; 佟健

    2004-01-01

    The crystal and molecular structures of K3[TbIII(nta)2(H2O)](5.5H2O (nta = nitrilotriacetic acid) and K3[YbIII(nta)2](5H2O complexes have been determined by single-crystal Xray structural analyses. Because TbIII and YbIII have different ionic radii and electronic configura- tions, they take nine- and eight-coordinate structures with two nta ligands, respectively. The crystal of K3[TbIII(nta)2(H2O)](5.5H2O belongs to orthorhombic, space group Pccn with a = 1.6374(7), b = 1.9913(8), c = 1.5068(6) nm, V = 4.913(3) nm3, Z = 8, Mr = 769.54, Dc = 2.081 g/cm3, μ= 3.476 mm-1 and F(000) = 3048. The final R and wR are 0.0432 and 0.0916 for 4961 observed reflections (I > 2.0(σI)), and 0.0814 and 0.1042 for all 21921 reflections, respectively. The [TbIII(nta)2(H2O)]3- complex anion has a nine-coordinate pseudo-monocapped square anti-prismatic structure, in which two N and six O coordinated atoms are from two nta ligands and the left ninth O atom from one water molecule. The crystal of K3[YbIII(nta)2]·5H2O is of monoclinic, space group P21/c with a = 1.5579(5), b = 0.9981(3), c = 1.5956(5) nm, β = 109.776(5), V = 2.3348(13) nm3, Z = 4, Mr = 756.62, Dc = 2.153 g/cm3, μ= 4.624 mm-1 and F(000) = 1484. The final R and wR are 0.0253 and 0.0657 for 4123 observed reflections (I > 2.0(σI)), and 0.0320 and 0.0731 for all 9414 reflections, respectively. The [YbIII(nta)2]3- complex anion has an eight-coordination structure with a distorted square antiprismatic prism, in which each nta acts as a tetradentate ligand with one N atom from the amino group and three O atoms from the carboxylic groups.

  1. Effect of Soil Water Stress on CO2/H2O Exchange Parameters in Wheat Leaves%水分胁迫对冬小麦叶片CO2/H2O交换参数的影响

    Institute of Scientific and Technical Information of China (English)

    张永强; 刘昌明; 杨永辉; 沈彦俊

    2001-01-01

    Changes of CO2/H2O exchange parameters were continually measuredin winter wheat under different water stress stages.The results showed that photosynthesis rate and transpiration rate of winter wheat in water stress conditions were obviously lower than that in non-stress conditions.After water stress,both of them slowly increased and even overtook that on sufficient irrigation treatment. Responses of winter wheat to water stress in different growth stages were different.To some extent, water stress can improve crop water use efficiency,speed up the process of milking.Under water stress condition,stomatal conductance limited diurnal changes of photosynthesis and transpiration in the morning but not in the afternoon.Transpiration is more sensitive to water stress than photosynthesis.

  2. 十四烷基二甲基苄基氯化铵的合成及晶体结构%Crystal Structure and Characterization of Tetradecyl Dimethyl Benzyl Ammonium Chloride C23H42ClN·2H2O

    Institute of Scientific and Technical Information of China (English)

    王瑛; 纪明中; 严莲荷

    2005-01-01

    合成了标题化合物C23H42ClN·2H2O (CCDC No: 227826),得到无色柱状晶体.晶体属正交晶系,空间群为P21/c, 晶胞参数a=2.0510(4)nm,b=1.1720(2) nm,c=1.0800(2) nm, V=2.5959(9) nm3,Mr=404.06,Z=4,Dc=1.034 g/cm3,F(000)=896,R=0.0590,wR=0.1789.4个C-N键的键长范围在0.1498(4)~0.1535(4) nm,热分析表明标题化合物在370.6 ℃完全分解.

  3. Synthesis and Structural Characterization of 2-Pyrazinecarboxylate Copper Compound {[Cu2 (Pyz) 2 (H2O) 4]·SO4}n (Pyz=2-pyrazinic acid)%2-吡嗪羧酸铜配合物的合成及其结构表征

    Institute of Scientific and Technical Information of China (English)

    禹良才; 赖兰

    2009-01-01

    Solvothermal reaction of 2-pyrazinic acid with Cu(SO4) 2·5H2O yields the title complex {[Cu2 (Pyz) 2 (H2O) 4]·SO4}n (1), which was characterized by elemental analysis, IR and single crystal X-ray diffraction structural analysis. The complex 1 crystallizes in Monoclinic system, space group P21/c, with lattice parameters a=1.126 87(6)nm, b=0.073 511 (4) nm,c=1.185 06(7) nm,β=95.070(2)°,and V=0.977 83(9) nm3,Z=4,Dc=2.172 Mg·m-3. CCDC:692347.

  4. Theoretical investigation of structure and stability of complexes with molecular hydrogen of Cu+·(H2)n (n=1-4) and L·Cu+·H2 (L=CO,N2,H2O,NH3,CN- and BH4-) type

    International Nuclear Information System (INIS)

    Nonempirical MO LCAO SCF method was used to calculate structures and stability of Cu+ ion complexes with molecular hydrogen of Cu+·(H2)n and L·Cu+·H2 (L+CO,N2,H2O,NH3,CN- and BH4-) type. It was found that energies of successive addition of H2 molecules decreased monotonously from ∼54 to ∼13 kJ with n growth from 1 to 4. Energy of Cu+-H2 bond decreases if additional ligands L enter the coordination sphere of Cu+. This weakening is more pronounced for L=CO,N2 and BH4- (by ∼6-8 kJ), as compared with H2O,NH3 and CN-. Qualitative model for explaining slight effects of mutual effect of L and H2 is suggested. It is shown that π-acceptor properties of L ligands are the most important ones

  5. Assay of hydroxyl radical produced by CO2 +/H2O2 reaction using alizarin violet spectrophotometry%茜素紫光度法检测H2 O2/CO2+产生的羟自由基

    Institute of Scientific and Technical Information of China (English)

    任凤莲; 吴南; 吴心传

    2000-01-01

    A method of determining hydroxyl radical produced by Co2 + -H2 O2 system by chromogenic reaction of oxida-tion of alizarin violet has been introduced in this paper. The new analytical system of Co2 + -H2 O2-alizafin violet has beenfirst put forward and applied to determine Hydroxyl radicals. In this method, hydroxyl radicals are produced utilizing thereaction of Co2+ -H2 02 resembling the Fenton reaction, and at the same time, the chromogenic reagent of alizarin violet isadded to change the color of alizarin violet. The amount of hydroxyl radicals can be calculated indirectly by determiningthe variety of value of △A by UV absorption spectrum. The sensitivity of method is wholly higher than the classic ways ofFenton reaction. The optimum condition has been found by researching into the condition of determination. According tothe result, it is found that an apparent Iinear relation exists in the anti-oxidation radicals such as ascorbic acid, benzoicacid and hydroxyl radical. The results show that in the maximum wave of 560 nm, there is an excellent linear relationshipexisting between the absorption of alizarin violet and the production of · OH. This method has a merit of good stability,handy operation and quick determination so that it can be easily adopted by general laboratory and applied to filtrate anti-oxidation radicals as a handy elihmination reagent. It is also an effective method to filtrate medicament of anti-oxidation%研究了用茜素紫的氧化来显色测定Co2+-H2O2体系产生羟自由基(·OH)的方法,提出CO2+-H2O2-茜素紫分析新体系并用于羟自由基(·OH)的测定.本方法利用Co2+与H2O2反应,类似Fenton试剂产生羟自由基(·OH),并加入茜素紫显色剂,使茜素紫的颜色发生变化,采用紫外.可见分光光度计测定其△A值的变化,可间接测定羟自由基的含量,且灵敏度高.研究结果表明:在最大吸收波长560nm处,茜素紫的吸光度与·OH产生量成良好

  6. Polynuclear complexes with bridging pyrophosphate ligands: synthesis and characterisation of {[(bipy)Cu(H2O)(mu-P2O7)Na2(H2O)6] x 4H2O}, {[(bipy)Zn-(H2O)(mu-P2O7)Zn(bipy)]2 x 14H2O} and {[(bipy)(VO)2]2(mu-P2O7)] x 5H2O}.

    Science.gov (United States)

    Doyle, Robert P; Nieuwenhuyzen, Mark; Kruger, Paul E

    2005-12-01

    The reaction in water of M(II) ions (M = Cu, 1; Zn, 2; VO, 3) with 2,2'-bipyridine (bipy) followed by Na4P2O7 leads to the formation of three new complexes which feature the pyrophosphate anion, P2O7(4-), as a bridging ligand. Single crystal X-ray diffraction revealed 1 to be {[(bipy)Cu(H2O)(micro-P2O7)Na2(H2O)6] x 4H2O}, and 2 as a tetranuclear Zn(II) complex, {[(bipy)Zn(H2O)(micro-P2O7)Zn(bipy)]2 x 14H2O}. The structure of 1 consists of a mononuclear [(bipy)Cu(H2O)(P2O7)]2- unit that links via a pyrophosphate bridge to two Na atoms. The hydrated six-coordinate Na atoms themselves join together through bridging water molecules to generate a 2D Na-water sheet. The structure of 2 consists of a tetranuclear Zn(II) cluster (dimer-of-dimers) with two pyrophosphate ligands bridging between four metal centres. Adjacent clusters interact through face-to-face pi-pi interactions via the bipy ligands to yield a 2D sheet. Adjacent sheets pack in register to create channels, which are filled by the water molecules of crystallisation. An intricate 2D H-bonded water network separates adjacent sheets and encapsulates the tetranuclear clusters. Aspects of the pyrophosphate coordination modes in 1 and 2 are of structural relevance to those found within the inorganic pyrophosphatases. Compound 3, {[(bipy)(VO)2]2(micro-P2O7)] x 5H2O}, was isolated as an insoluble lime-green powder. Its dinuclear structure was elucidated from elemental and thermal analysis, magnetic susceptibility measurement and IR spectroscopy. The latter displayed characteristic bridging pyrophosphate and signature V=O stretches, which were corroborated by contrast to the IR spectra of 1 and 2 and through comparison with those found in the structurally characterised dinuclear complex, {[(bipy)Cu(H2O)]2(micro-P2O7) x 7H2O}, 4. PMID:16471055

  7. Synthesis of high quality CdSe quantum dots through a mild solution-phase synthetic route

    International Nuclear Information System (INIS)

    High quality CdSe quantum dots are synthesized through a solution-phase synthesis technique with Cd(CH3COO)2.2H2O and Na2SeSO3 as precursors. In this synthesis approach, the participation of a novel terpyridine derivative provides much better control over growth dynamics of CdSe quantum dots, resulting in the suppression of the Ostwald ripening process of the particle size distribution during growth. The CdSe quantum dots meet the all requirements of high quality quantum dots.

  8. NMR investigation on isotope effect of glycinium phosphite H sub 3 NCH sub 2 COOH centre dot H sub 2 PO sub 3

    CERN Document Server

    Ishibashi, T

    2003-01-01

    The motions of the phosphite anions and glycinium cations in H sub 3 NCH sub 2 COOH centre dot H sub 2 PO sub 3 (GPI) and its deuterated analogue (DGPI) were investigated by sup 1 H, sup 1 sup 3 C and sup 3 sup 1 P spin-lattice relaxation times T sub 1. For both GPI and DGPI, T sub 1 's of the sup 1 H, sup 1 sup 3 C and sup 3 sup 1 P nuclei reflect the amino rotation, methylene libration and motion of the phosphite anions, respectively. Activation energies obtained from T sub 1 's of sup 1 H, sup 1 sup 3 C and sup 3 sup 1 P nuclei are 28.6(2), 26.0(4) and 26.2(4) kJ/mol for GPI and are 34.9(6), 27(1), 47(2) kJ/mol for DGPI, respectively. The deuterium substitution increases E sub a for the motion influenced by the hydrogen bonding. In all the observed motions, correlation times of DGPI are larger than those of GPI. (author)

  9. Aspects of the historical development of targetry for heavy ions of 0.05-2000 A centre dot MeV at GSI

    CERN Document Server

    Folger, H

    1999-01-01

    The progressively improved GSI accelerators provide beams of heavy ions from energies of 0.05-2000 A centre dot MeV at high particle intensities now. Therefore, a wide variety of common and new heavy-ion target techniques had to be installed and developed during the past 25 years to prepare and characterize self-supported or backed heavy-ion-targets of chemical elements and compounds from hydrogen (as polyethylene) to uranium. The thickness ranged from 2x10 sup - sup 6 to 20 g/cm sup 2 for beam spots of about 5 mm in diameter. Homogeneity, surface structure or individual shape had to be adapted to the needs of each experiment. Special setups were required for targets of poisonous materials, of highly enriched stable isotopes or those of radioactive species in minute amounts. The capability of thin-layer technologies was as well applied to prepare and measure stripper foils or various high-vacuum deposits for experimental or accelerator purposes. The development of different rotating target wheels and control ...

  10. Two mixed-ligand lanthanide–hydrazone complexes: [Pr(NCS3(pbh2]·H2O and [Nd(NCS(NO3(pbh2(H2O]NO3·2.33H2O [pbh is N′-(pyridin-2-ylmethylidenebenzohydrazide, C13H11N3O

    Directory of Open Access Journals (Sweden)

    Damianos G. Paschalidis

    2016-02-01

    Full Text Available The gel-mediated syntheses and crystal structures of [N′-(pyridin-2-ylmethylidene-κNbenzohydrazide-κ2N′,O]tris(thiocyanato-κNpraseodymium(III monohydrate, [Pr(NCS3(C13H11N3O2]·H2O, (I, and aqua(nitrato-κ2O,O′[N′-(pyridin-2-ylmethylidene-κNbenzohydrazide-κ2N′,O](thiocyanato-κNneodymium(III nitrate 2.33-hydrate, [Nd(NCS(NO3(C13H11N3O2(H2O]NO3·2.33H2O, (II, are reported. The Pr3+ ion in (I is coordinated by two N,N,O-tridentate N′-(pyridin-2-ylmethylidenebenzohydrazide (pbh ligands and three N-bonded thiocyanate ions to generate an irregular PrN7O2 coordination polyhedron. The Nd3+ ion in (II is coordinated by two N,N,O-tridentate pbh ligands, an N-bonded thiocyanate ion, a bidentate nitrate ion and a water molecule to generate a distorted NdN5O5 bicapped square antiprism. The crystal structures of (I and (II feature numerous hydrogen bonds, which lead to the formation of three-dimensional networks in each case.

  11. Synthesis and Physico-chemical studies of a new non-centrosymmetric organic-inorganic hybrid material: [2,3-(CH3)2C6H3NH3]4 BiBr6NO3.2H2O

    Indian Academy of Sciences (India)

    Z Aloui; V Ferretti; S Abid; M Rzaigui; C Ben Nasr

    2015-03-01

    Organic-inorganic hybrid single crystals of [2,3-(CH3)2C6H3NH3]4BiBr6NO3.2H2O were obtained by slow evaporation at room temperature and characterized by X-ray diffraction, IR and solid state NMR. This compound crystallizes in orthorhombic non-centrosymmetric space group Pca21 with the following lattice parameters: a=25.8217(1), b=7.8909(2), c=21.4328(3) Å, V=4367.07(13) Å3 and Z=4. The structure was refined to R = 0.057 for 7069 independent reflections. The crystal is built up of 2,3-dimethylanilinium cations, [BiBr66]3−, disordered [NO3] anions and water molecules. The crystal packing is governed by a threedimensional network of O-H... O, N-H... O and N-H... Br hydrogen bonds and van derWaals interaction. The infrared spectrum has been interpreted on the basis of literature data. Solid state 13C CP-MAS-NMR spectrum is in agreement with the X-ray structure.

  12. Synthesis and structural characterisation of new ettringite and thaumasite type phases: Ca6[Ga(OH)6·12H2O]2(SO4)3·2H2O and Ca6[M(OH)6·12H2O]2(SO4)2(CO3)2, M = Mn, Sn

    Science.gov (United States)

    Norman, Rachel L.; Dann, Sandra E.; Hogg, Simon C.; Kirk, Caroline A.

    2013-11-01

    Investigations into the formation of new ettringite-type phases with a range of trivalent and tetravalent cations were carried out to further study the potential this structure type has to incorporate cations covering a range of ionic radii (0.53-0.69 Å). We report the synthesis and structural characterisation of a new ettringite-type phase, Ca6[Ga(OH)6·12H2O]2(SO4)3·2H2O, which was indexed in space group P31c with the unit cell parameters a = 11.202(2) Å, c = 21.797(3) Å and two new thaumasite-type phases Ca6[M(OH)6·12H2O]2(SO4)2(CO3)2, M = Mn, Sn which were indexed in space group P63 with the unit cell parameters a = 11.071(5) Å, c = 21.156(8) Å and a = 11.066(1) Å, c = 22.420(1) Å respectively. These new phases show the versatility of the ettringite family of structures to tolerate a large range of cation sizes on the octahedral M site and highlights the preference of tetravalent cations to crystallise with the thaumasite structure over the ettringite structure.

  13. Diffuse reflection infrared Fourier transform (DRIFT) spectra and high-temperature DRIFT spectra of beta-Ni(IO3)2.4H2O, Ni(IO3)2.2H2O, Mg(OH)2, and Zn(OH)F: novel embedding materials.

    Science.gov (United States)

    Pracht, G; Weckler, B; Lutz, H D

    2003-10-01

    Diffuse reflection infrared Fourier transform (DRIFT) spectra of the hydroxides Mg(OH)2 and Zn(OH)F and the iodate hydrates beta-Ni(IO3)2.4H2O and Ni(IO3)2.2H2O have been recorded at ambient and high temperature. Spectra without shifts of the band maxima compared to those of conventional infrared transmission spectra and without inversion of the bands were obtained by dilution of the compounds to about 2-10% with an appropriate embedding material. alpha-Al2O3, TiO2, ZrO2, PbF2, MgO, BaO, ZnO, Na2SiO3, SiO2 (aerosil), and powdered copper, aluminum, and magnesium were tested as diluents for hydrates and hydroxides, especially at elevated temperatures, as alternatives for the commonly used KBr. Thus, alpha-Al2O3, PbF2, and powdered copper were established as the most favorable diluents. Using these novel embedding materials, high-temperature DRIFT spectra are obtainable at temperatures not accessible with KBr discs. Dehydration and decomposition of the iodate hydrates under study were shown by change or disappearance of the respective water bands. PMID:14639754

  14. Two different zinc(II)-aqua complexes held up by a metal-oxide based support: Synthesis, crystal structure and catalytic activity of [HMTAH]2[{Zn(H2O)5}{Zn(H2O)4}{Mo7O24}].2H2O (HMTAH = protonated hexamethylenetetramine)

    Indian Academy of Sciences (India)

    T Arumuganathan; A Srinivasarao; T Vijay Kumar; Samar K Das

    2008-01-01

    An inorganic−organic hybrid material, [HMTAH]2[{Zn(H2O)5}{Zn(H2O)4}{Mo7O24}].2H2O (1) (where HMTAH = protonated hxamethylenetetramine) has been synthesized and structurally characterized. The compound 1 crystallizes in a monoclinic space group 2/. The crystal data of 1: = 43.12(3), = 12.399(10), = 16.285(13), = 111.131(11), = 8. Its crystal structure shows that two different Zn(II)-aqua complexes, [Zn(H2O)5]2+ and [Zn(H2O)4]2+ are covalently coordinated to a heptamolybdateanion [Mo7O24]6- resulting in an anionic species of polyoxometalate supported zinc-aqua complexes, [{Zn(H2O)}{Zn(H2O)4}{Mo7O24}]2-, that is stabilized with two protonated hexamethylenetetramine cations in the title compound 1. In the crystal structure, both lattice water molecules are found to interact with the heptamolybdate cluster anion and the protonated hexamethylenetetramine cation resulting in an intricate three-dimensional hydrogen bonding network. Interestingly, compound 1 exhibits catalytic activity towards oxidation of some primary alcohols.

  15. Synthesis, structural characterization, and solid-state NMR spectroscopy of [Ga(phen)(H1.5PO4)2].H2O and [Ga(phen)(HPO4)(H2PO4)].1.5H2O (phen=1, 10-phenanthroline), two organic-inorganic hybrid compounds with 1-D chain structures

    International Nuclear Information System (INIS)

    Two new organic-inorganic hybrid compounds, [Ga(phen)(H1.5PO4)2].H2O (1) and [Ga(phen)(HPO4)(H2PO4)].1.5H2O (2) (phen=1,10-phenanthroline), have been synthesized by hydrothermal methods and structurally characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, and solid-state NMR spectroscopy. Their structures consist of 1-D chains of strictly alternating GaO4N2 octahedra and phosphate tetrahedra. The phen ligands in both compounds bind in a bidentate fashion to the gallium atoms and the 1-D structures extend into 3-D supramolecular arrays via π-π stacking interactions of phen ligands and hydrogen bonds. 2H MAS NMR spectroscopy was applied to study the deuterated sample of 1 which contains very short hydrogen bonds with an O-O distance of 2.406(2) A. Crystal data for 1: monoclinic, space group C2/c (No. 15), a=11.077(1) A, b=21.496(2) A, c=7.9989(7) A, β=127.211(2)o, and Z=4. The crystal symmetry is the same for 2 as for 1 except a=27.555(2) A, b=6.3501(5) A, c=21.327(2) A, β=122.498(1)o, and Z=8

  16. 新型三维刚柔多羧酸稀土配位聚合物,[Sm(μ3-O)(nic)3(ad)0.5(H2O)]和[Pr(nic)(ad)·2H2O]的水热合成、结构和性质

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      利用水热合成方法,以刚性羧酸配体烟酸或均苯四甲酸为第一配体,以柔性羧酸配体己二酸为第二配体,我们成功设计合成了2个结构新颖的稀土配位聚合物,[Sm(μ3-O)(nic)3(ad)0.5(H2O)](1),[Pr(nic)(ad)·2H2O](2)(H4btec=1,2,4,5-均苯四甲酸;Hnic=烟酸;H2ad=己二酸)并通过元素分析、红外光谱、X 射线单晶结构分析对标题配合物进行了表征.此外,我们还对标题化合物的热稳定性做了详细的分析.

  17. Sulfitos duplos contendo cobre (I e um metal de transição M(II tipo Cu2SO3.M(IISO3.2H 2O [M(II = Cu(II, Fe(II, Mn(II e Cd(II]: preparação e seletividade na incorporação de M(II Double sulfite containing copper (I and a metal transition M(II like Cu2SO3.M(IISO3.2H 2O [M(II = Cu(II, Fe(II, Mn(II and Cd(II]: synthesis and selectivity in M(II incorporation

    Directory of Open Access Journals (Sweden)

    Luciana Almeida Silva

    1998-04-01

    Full Text Available The metal-catalyzed autooxidation of S(IV has been studied for more than a century without a consensus being obtained as to reaction rates, rate laws or mechanisms. The main objective in this work was to explore the reaction between Cu(II and SO2 in the presence of M(II, paying special attention to the formation of double sulfites like Cu2SO3.M(IISO3.2H 2O. The two principal aspects studied were: i a new way to prepare double sulfites with high purity degree and the selectivity in the M(II incorporation during the salt formation.

  18. A kinetic study of the reactions of Fe+ with N2O, N2, O2, CO2 and H2O, and the ligand-switching reactions Fe+.X + Y --> Fe+.Y + X (X = N2, O2, CO2; Y = O2, H2O).

    Science.gov (United States)

    Vondrak, T; Woodcock, K R I; Plane, J M C

    2006-01-28

    A series of reactions involving Fe(+) ions were studied by the pulsed laser ablation of an iron target, with detection of ions by quadrupole mass spectrometry at the downstream end of a fast flow tube. The reactions of Fe(+) with N(2)O, N(2) and O(2) were studied in order to benchmark this new technique. Extending measurements of the rate coefficient for Fe(+) + N(2)O from 773 K to 185 K shows that the reaction exhibits marked non-Arrhenius behaviour, which appears to be explained by excitation of the N(2)O bending vibrational modes. The recombination of Fe(+) with CO(2) and H(2)O in He was then studied over a range of pressure and temperature. The data were fitted by RRKM theory combined with ab initio quantum calculations on Fe(+).CO(2) and Fe(+).H(2)O, yielding the following results (120-400 K and 0-10(3) Torr). For Fe(+) + CO(2): k(rec,0) = 1.0 x 10(-29) (T/300 K)(-2.31) cm(6) molecule(-2) s(-1); k(rec,infinity) = 8.1 x 10(-10) cm(3) molecule(-1) s(-1). For Fe(+) + H(2)O: k(rec,0) = 5.3 x 10(-29) (T/300 K)(-2.02) cm(6) molecule(-2) s(-1); k(rec,infinity) = 2.1 x 10(-9) (T/300 K)(-0.41) cm(3) molecule(-1) s(-1). The uncertainty in these rate coefficients is determined using a Monte Carlo procedure. A series of exothermic ligand-switching reactions were also studied at 294 K: k(Fe(+).N(2) + O(2)) = (3.17 +/- 0.41) x 10(-10), k(Fe(+).CO(2) + O(2)) = (2.16 +/- 0.35) x 10(-10), k(Fe(+).N(2) + H(2)O) = (1.25 +/- 0.14) x 10(-9) and k(Fe(+).O(2) + H(2)O) = (8.79 +/- 1.30) x 10(-10) cm(3) molecule(-1) s(-1), which are all between 36 and 52% of their theoretical upper limits calculated from long-range capture theory. Finally, the role of these reactions in the chemistry of meteor-ablated iron in the upper atmosphere is discussed. The removal rates of Fe(+) by N(2), O(2), CO(2) and H(2)O at 90 km altitude are approximately 0.1, 0.07, 3 x 10(-4) and 1 x 10(-6) s(-1), respectively. The initially formed Fe(+).N(2) and Fe(+).O(2) are converted into the H(2)O complex at

  19. 配聚物[Cd2(2,5-pdc)2(H2O)4]n的光电性能%The photo-electric propery of the polymer[Cd2 (2,5-pdc)2 (H2 O)4 ]n

    Institute of Scientific and Technical Information of China (English)

    牛淑云; 计雅楠; 刘佳操; 丁榆

    2014-01-01

    The polymer [Cd2 (2 ,5-pdc)2 (H2 O)4 ]n has been synthesized by hydrothermal method with the 2 ,5-H2 pdc as ligand .The crystal structure of the polymer was determined by single crystal X ray diffraction .Structural analysis shows that the asymmetric unit is Cd2(2 ,5-pdc)2(H2O)4 ,in which the two independent Cd(Ⅱ )ions(Cd1 and Cd2)are all six-coordinated .In the crystal ,Cd(Ⅱ )ions are bridged by the O atoms of pdc2 - groups into 2D extended structure .Moreover ,the intermolecular H-bonds connect 2D layers into 3D structure .The photo-electric property of the polymer was investiga-ted by surface photovoltage spectroscopy (SPS) .The result indicates that the polymer exhibits posi-tive surface photovoltage responses in the range of 300~800 nm ,so it possesses certain photo-electric conversion property .The UV-Vis-NIR and IR spectra of the polymer were measured and analyzed . And the SPS spectrum has been related with its UV-Vis-NIR spectrum .%采用水热合成法,以2,5-吡啶-二羧酸为配体,得到了Cd(Ⅱ)配聚物:[Cd2(2,5-pdc)2(H2 O )4]n (2,5-H2 pdc=2,5-吡啶-二羧酸)。采用X射线单晶衍射确定了配聚物的晶体结构。配聚物的不对称单元为 Cd2(2,5-pdc)2(H2 O)4,其中两个不等效的金属Cd(Ⅱ)离子均为6配位。在配聚物晶体中,Cd(Ⅱ)离子之间通过pdc2-上的羧基O原子连接,形成了具有2D结构的配聚物,氢键进一步将其连接成3D超分子。采用表面光电压光谱(S PS )研究了配聚物的表面光电性能。结果表明,该配聚物在300~800 nm范围内呈现出较强的光伏响应,表明他具有一定的光-电转换能力。对配聚物的 U V-Vis-NIR吸收光谱、IR光谱进行了测定和指认,并将 SPS 谱与 UV-Vis-NIR 吸收光谱进行了关联。

  20. Linearly Tetrameric Water Cluster Stabilized by Cyano Groups of Multicomplex [Zn(2,2’-bipyridine)3][Zn(CN)4]·2H2O%[Zn(2,2’-bipyridine)3][Zn(CN)4]·2H2O复配物中线型四聚水簇

    Institute of Scientific and Technical Information of China (English)

    曹鹏; 何军

    2016-01-01

    A hydrothermal reaction of Zn(CN)2, 2,2’-bipyridine(bipy)afforded a novel multicomplex, [Zn(bipy)3][Zn(CN)4]·2H2O(1), which features a 2D supramolecular network assembled from unprecedented linear water tetramers and anionic [Zn(CN)4]2- moieties through intricate hydrogen bonding interactions. Single-crystal X-ray diffraction, FT-IR, thermogravimetric analysis and photoluminescence spectrum of 1 also have been discussed. 1 exhibits strong photoluminescence maximized at 437 nm upon 310 nm excitation at ambient temperature, of which is close to that of the greenish light.%通过水热合成法,利用Zn(CN)2,2,2’-联吡啶合成出一种新颖的复配物[Zn(bipy)3][Zn(CN)4]·2H2O(1),它的特点是通过复杂的氢键作用,将一种结构新颖的线性四聚体水簇和[Zn (CN)4]2-负电基团连接组装成一种二维超分子网络。并对1进行了包括单晶X-射线衍射、红外、热重以及荧光发射在内的表征与分析。研究发现在室温下310 nm的紫外光激发下,1表现出强烈的荧光发射性质,且发射光波长为437 nm,与绿光非常接近。

  1. Layered Lanthanum Complex with 3-Nitrophthalic Acid Assembled via Hydrogen Bonds-Synthesis, Structure and Characterization of [LaL(HL)(H2O)3]2·2H2O (H2L = 3-NO2C6H3(CO2H)2)

    Institute of Scientific and Technical Information of China (English)

    DENG Yu-Heng; LIU Juan; YANG Yong-Li; ZHU Hui-Ju; MA Hong-Wei

    2007-01-01

    A new dinuclear centrosymmetric complex [LaL(HL)(H2O)3]2(2H2O (H2L = 3-nitrophthalic acid, NPA) was synthesized in water/ethanol solution and characterized by X-ray diffraction, IR spectrum and TGA-DTA. The complex crystallizes in triclinic system, space group P-1 with a = 8.1549(16), b = 8.8856(18), c = 15.277(3)(A),α= 100.93(3),α= 90.81(3), γ= 104.56(3)°, V = 1049.8(4)(A)3, Z = 1,μ= 2.125 mm-1, Dc=1.994 g/cm3, R = 0.0259 and wR = 0.0679. Two 3-nitrophthalates(2-) coordinate with the La3+ ions in a bridging mode, and two monohydrogen- 3-nitrophthates(1-) and three waters in terminal ways, respectively. Each La3+ ion is nine-coordinated to exhibit a distorted tricapped trigonal prism coordination polyhedron. Both the coordinated and crystal waters are involved in the inter- and intramolecular hydrogen bonds. The dinuclear units are linked into a 2D network structure in the ab plane via intermolecular hydrogen bonds along the axes a and b. Two crystal waters fill each rhombic pore of the network. The networks are further packed along the c axis forming a layered supramolecular structure through the C-H…O weak forces between the adjacent sheets. TGA analysis shows the complex undergoes the loss of waters of crystallization and coordination and the decomposition of ligands sequentially.

  2. Crystal structures of two decavanadates(V with pentaaquamanganese(II pendant groups: (NMe42[V10O28{Mn(H2O5}2]·5H2O and [NH3C(CH2OH3]2[V10O28{Mn(H2O5}2]·2H2O

    Directory of Open Access Journals (Sweden)

    Maurício P. Franco

    2015-02-01

    Full Text Available Two heterometallic decavanadate(V compounds, bis(tetramethylammonium decaaquadi-μ4-oxido-tetra-μ3-oxido-hexadeca-μ2-oxido-hexaoxidodimanganese(IIdecavanadate(V pentahydrate, (Me4N2[V10O28{Mn(H2O5}2]·5H2O, A, and bis{[tris(hydroxymethylmethyl]ammonium} decaaquadi-μ4-oxido-tetra-μ3-oxido-hexadeca-μ2-oxido-hexaoxidodimanganese(IIdecavanadate(V dihydrate, [NH3C(CH2OH3]2[V10O28{Mn(H2O5}2]·2H2O, B, have been synthesized under mild reaction conditions in an aqueous medium. Both polyanions present two [Mn(OH25]2+ complex units bound to the decavanadate cluster through oxide bridges. In A, the decavanadate unit has 2/m symmetry, whereas in B it has twofold symmetry. Apart from this, the main differences between A and B rest on the organic cations, tetramethylammonium and [tris(hydroxymethylmethyl]ammonium, respectively, and on the number and arrangement of the water molecules of crystallization. In both compounds, the H atoms from the coordinating water molecules participate in extensive three-dimensional hydrogen-bonding networks, which link the cluster units both directly and through solvent molecules and, in B, through the `tris' cation hydroxyl groups. The cation in B also participates in N—H...O hydrogen bonds. A number of C—H...O interactions are also observed in both structures.

  3. Energies and wave functions of an off-centre donor in hemispherical quantum dot: Two-dimensional finite difference approach and ritz variational principle

    Science.gov (United States)

    Nakra Mohajer, Soukaina; El Harouny, El Hassan; Ibral, Asmaa; El Khamkhami, Jamal; Assaid, El Mahdi

    2016-09-01

    Eigenvalues equation solutions of a hydrogen-like donor impurity, confined in a hemispherical quantum dot deposited on a wetting layer and capped by an insulating matrix, are determined in the framework of the effective mass approximation. Conduction band alignments at interfaces between quantum dot and surrounding materials are described by infinite height barriers. Ground and excited states energies and wave functions are determined analytically and via one-dimensional finite difference approach in case of an on-center donor. Donor impurity is then moved from center to pole of hemispherical quantum dot and eigenvalues equation is solved via Ritz variational principle, using a trial wave function where Coulomb attraction between electron and ionized donor is taken into account, and by two-dimensional finite difference approach. Numerical codes developed enable access to variations of donor total energy, binding energy, Coulomb correlation parameter, spatial extension and radial probability density with respect to hemisphere radius and impurity position inside the quantum dot.

  4. Precipitation kinetics of calcite in the system CaCO 3H2OC02: The conversion to CO 2 by the slow process H ++HCO 3- → CO 2+H 2O as a rate limiting step

    Science.gov (United States)

    Dreybrodt, W.; Eisenlohr, L.; Madry, B.; Ringer, S.

    1997-09-01

    Precipitation rates of CaCO 3 from supersaturated solutions in the H 2OCO 2CaCO 3 system are controlled by three rate-determining processes: the kinetics of precipitation at the mineral surface, mass transport of the reaction species involved to and from the mineral surface, and the slow kinetics of the overall reaction HCO 3-+H + → CO 2+H 2O. A theoretical model by Buhmann and Dreybrodt (1985a,b) taking these processes into account predicts that, due to the slow kinetics of this reaction, precipitation rates to the surface of CaC0 3 minerals depend critically on the ratio V/A of the volume V of the solution to the surface area A of the mineral in contact with it, for both laminar and turbulent flow. We have performed measurements of precipitation rates in a porous medium of sized particles of marble, limestone, and synthetic calcite, with V/A ratios ranging from 3·10 -4 to 1.2·10 -2 cm at 10°C. Calcite was precipitated from supersaturated solutions with [Ca 2+] ≈ 4 mmol/L and an initial PCO2 of 5·10 -3 or 1·10 -3 atm, respectively, using experimental conditions which prevented exchange of CO 2 with the atmosphere, i.e., closed system. The results are in qualitative agreement with the theoretical predictions. Agreement with the observed data, however, is obtained by modifying the rate law of Plummer et al. (1978) to take into account surface-controlled inhibition effects. Experiments with supersaturated solutions containing carbonic anhydrase, an enzyme which enhances the conversion of HCO 3- into CO 2, yield rates increased by a factor of up to 15. This provides for the first time unambiguous experimental evidence that this reaction is rate limiting. We have also measured precipitation rates in batch experiments, stirring sized mineral particles in a solution with V/A ranging from 0.03 to 0.75 cm. These experiments also give clear evidence on the importance of the conversion of HCO 3- into CO 2 as rate limiting step. Taken together our experiments

  5. The Order-Disorder of the Structure of V OHPO4.0.5H2O Preparedby Reducing VOPO4.2H2O with Alcohol%醇还原VOPO4.2H2O制备VOHPO4.0.5H2O的有序-无序结构

    Institute of Scientific and Technical Information of China (English)

    王晓晗; 马荣萱; 卢冠忠; 黄仲涛

    2001-01-01

    在醇还原VOPO4*2H2O制备VOHPO4*0.5H2O的反应中,不同空间构型的醇对VOHPO4*0.5H2O晶体的有序-无序结构有较大的影响。醇既是还原剂又是模板剂,对晶体的生长起到模板作用。由伯醇制备的VOHPO4*0. 5H2O晶体在[220]晶面有较强衍射,晶体结构部分无序,晶型为扭曲片状聚集体;由仲醇制备的VOHPO4*0.5H2O晶体在[001]晶面有较强衍射,晶体结构完全有序,晶型为片状聚集体。%Alcohol may act as a template as well as a reducing agent during the conversion of VOPO4.2H2O to VOHPO4.0.5H2O.On re ducing V(Ⅴ) to V(Ⅳ) the alcohols of diff erent steric configurations play a templ ate role in the process of VOHPO4.0.5H 2O crystal growth,and influence the orde r-disorder of the structure of VOHPO4.0 .5H2O.VOHPO4*0.5H2O crystals prepared by 1-alcohols exhibit [220] reflection in the diffraction pattern,partial disor der of structure and rose-like morpholog y.VOHPO4.0.5H2O crystals prepared by 2 -alcohols exhibit the dominant feature o f [001] reflection,complete order of st ructure and platelet morphology.

  6. 膜蒸馏-结晶耦合从高浓度KCl-MgCl2-H2O溶液中回收KCl%Recovery of KCl crystalline product from highly concentrated KCl-MgCl2-H2O solution with membrane distillation crystallization

    Institute of Scientific and Technical Information of China (English)

    关云山; 武警; 程文婷; 李剑锋; 程芳琴; 王旭明

    2015-01-01

    Highly concentrated KCl and MgCl2solutions were treated with direct contact membrane distillation (DCMD). The effects of salt concentration (1.0—4.0 mol·L−1) and circulation velocity (0.1—0.5 m·s−1) on permeate flux were investigated. Permeate flux decreased with increasing concentration, which was attributed to vapor pressure reduction caused by decrease of water activity in the solution. Reversed flux occurred in the DCMD process of highly concentrated MgCl2solution (>3.0 mol·L−1) under the test conditions, which was due to the combined effect of lower water activity and higher viscosity of the fluid. Permeate fluxes increased with increasing circulation velocity, which was more effective to reduce the negative effect of temperature and concentration polarization for MgCl2solution with higher viscosity. Membrane distillation-crystallization (MDC) of a highly concentrated solution of KCl-MgCl2-H2O was investigated for recovery of KCl crystalline product and pure water with batch operation mode. The effect of way of cooling on supersaturation of solution, morphology, and crystal size distribution was studied. KCl crystalline product with regular shape, tidy surface and concentrated particle size distribution was obtained by natural cooling and maximum degree of supercooling generated under natural cooling was lower than under quick cooling, which was beneficial to control nucleation amount and growth rate of KCl.%用直接接触膜蒸馏处理高浓度的KCl和MgCl2溶液,考察了盐水浓度(1.0~4.0 mol·L−1)、循环流速(0.1~0.5 m·s−1)对膜蒸馏性能的影响;结果表明:随着盐水浓度的升高,膜通量下降,这是由于盐溶液的蒸汽压(即溶液中水的活度)下降的缘故;当浓度超过3.0 mol·L−1时,MgCl2溶液的膜通量出现负值,这主要归结为MgCl2溶液低的水的活度和高黏度的协同影响;提高循环流速,膜通量增大,尤其对高黏度的盐水(即 Mg

  7. Ultra-large scale synthesis of high electrochemical performance SnO2 quantum dots within 5 min at room temperature following a growth self-termination mechanism

    International Nuclear Information System (INIS)

    Highlights: • SnO2 quantum dots were prepared at an ultra-large scale at room temperature within 5 min. • The grinding of SnCl2⋅2H2O and ammonium persulphate with morpholine produces quantum dots. • The reactions were self-terminated through the rapid consumption of water. • The obtained SnO2 quantum dots own high electrochemical performance. - Abstract: SnO2 quantum dots are prepared at an ultra-large scale by a productive synthetic procedure without using any organic ligand. The grinding of solid mixture of SnCl2⋅2H2O and ammonium persulphate with morpholine in a mortar at room temperature produces 1.2 nm SnO2 quantum dots within 5 min. The formation of SnO2 is initiated by the reaction between tin ions and hydroxyl groups generated from hydrolysis of morpholine in the released hydrate water from SnCl2⋅2H2O. It is considered that as water is rapidly consumed by the hydrolysis reaction of morpholine, the growth process of particles is self-terminated immediately after their transitory period of nucleation and growth. As a result of simple procedure and high toleration to scaling up of preparation, at least 50 g of SnO2 quantum dots can be produced in one batch in our laboratory. The as prepared quantum dots present high electrochemical performance due to the effective faradaic reaction and the alternative trapping of electrons and holes

  8. Inversion of spin levels in Ni sup 2 sup + : Zn(BF sub 4) sub 2 centre dot 6H sub 2 O at all -round compression and effect of transition coincidence

    CERN Document Server

    Krygin, I M; Nejlo, G N; Prokhorov, A D

    2001-01-01

    The study of the EPR spectrum of the Ni sup 2 sup + ion, replacing Zn sup 2 sup + in the Zn(BF sub 4) centre dot 6H sub 2 O crystals in the wide temperature range by the all-round compression in the X- and Q-ranges is carried out. The basic changes by varying temperature and pressure occur with the D parameter, characterizing the initial splitting by practically unchanged g-factor. The increase in the temperature is accompanied by the D nonlinear growth. The all-round compression linearly changes the initial splitting and leads to the change in the D-sign, signifying the spin levels inversion by 3.5 kbar. Coincidence of EPR lines, relative to different transitions, leads to the crevasse appearance in the outline of this one, that is connected with cross-relaxation inside the spin system

  9. Infrared Spectra of the CO_2-H_2O, CO_2-(H_2O)2, and (CO_2)2-H_2O Complexes Isolated in Solid Neon Between 90 and 5300 wn

    Science.gov (United States)

    Tremblay, Benoît; Soulard, Pascale

    2015-06-01

    The van der Waals complex of H_2O with CO_2 has attracted considerable theoretical interest since it is a typical example of a weak binding complex (less than 3 kcal/mol), but a very few IR data are available in gas. For these reasons, we have studied in solid neon hydrogen bonded complexes involving carbon dioxide and water molecules. Evidence for the existence of at least three (CO_2)m(H_2O)n, or m:n, complexes has been obtained from the appearance of many new absorptions near the well-know monomers fundamental transitions. Concentration effects and detailed vibrational analysis allowed identification of fifteen, eleven and four transitions for the 1:1, 1:2, and 2:1 complexes, respectively. Careful examination of the far infrared allows the assignment of several 1:1 and 1:2 intermolecular modes, confirmed by the observation of combinations of intra+intermolecular transitions. All of these results significantly increase the number of one and, especially, two quanta vibrational transitions observed for these complexes, and anharmonic coupling constants have been derived. This study shows the high sensibility of the solid neon isolation for the spectroscopy of the hydrogen-bonded complexes since two quanta transitions can't be easily observed in gas phase.

  10. Magnetic susceptibility of Co sup 2 sup + pairs in [Co sub 2 (ox)tpmc](ClO sub 4) sub 2 centre dot 3H sub 2 O cluster complex

    CERN Document Server

    Spasojevic, V; Sovilj, S P; Mrozinski, J

    2000-01-01

    Calculation of the magnetic susceptibility of Co sup 2 sup + pairs in the recently synthesized cobaltous cluster complex [Co sub 2 (ox)tpmc](ClO sub 4) sub 2 centre dot 3H sub 2 O has been conducted by the use of two different theoretical models. The calculated results were compared to the experimental data collected in a wide temperature region. Conclusions on both the magnetic properties of Co sup 2 sup + dimers and the validity of the proposed models have been drawn. In the temperature region above chi(T) maximum, the best results are obtained with the Heisenberg model that includes spin-orbit coupling and excited single-ion levels. In the low-temperature region anisotropy of the magnetic properties dominates and Ising dimer ground-state model gives a more appropriate description. Obtained g-values (g sub p sub a sub r sub a sub l sub l sub e sub l a=5.67, g sub p sub a sub r sub a sub l sub l sub e sub l b=5.73, and g sub p sub e sub r sub p sub e sub n sub d sub i sub c sub u sub l sub a sub r =1.54) con...

  11. Crystal and molecular structure of four copper(II) ethylenediaminedisuccinates, [Cu2(RR,SS-Edds)] . 6H2O, Ba2[Cu(RR,SS-Edds)](ClO4)2 . 8H2O, Ba[Cu(SS-HEdds)]ClO4 . 2H2O, and Ba3[Cu2(RR,SS-Edds)2](ClO4)2 . 6H2O

    International Nuclear Information System (INIS)

    Four Cu(II) complexes with the RR,SS-Edds4- and SS-HEdds3- anions are synthesized, and their crystal structures are studied. In the compounds [Cu2(RR,SS-Edds)] . 6H2O (I) and Ba2[Cu(RR,SS-Edds)](ClO4)2 . 8H2O (II), the ligand forms hexacoordinate chelate [Cu(Edds)]2- complexes with the N atoms and O atoms of the propionate groups in the equatorial positions and the O atoms of the acetate groups in the axial vertices. In the compounds Ba[Cu(SS-HEdds)]ClO4 . 2H2O (III) and Ba3[Cu2(RR,SS-Edds)2](ClO4)2 . 6H2O (IV), one of the propionate arms, the protonated arm in III and the deprotonated arm in IV, does not enter into the coordination sphere of the Cu atom. An acetate arm moves to its position in the equatorial plane, and the free axial vertex is occupied by an O atom of the perchlorate ion. In I-IV, the lengths of the equatorial Cu-N and Cu-O bonds fall in the ranges 1.970-2.014 and 1.921-1.970 A, respectively. The axial Cu-O bonds with the acetate groups and ClO4- anions are elongated to 2.293-2.500 and 2.727-2.992 A, respectively. In structure I, the second Cu atom acts as a counterion forming bonds with the O atoms of two water molecules and three O atoms of the Edds ligands. In II-IV, the Ba2+ cations are hydrated and bound to the O atoms of the anionic complexes and (except for one of the cations in IV) ClO4- anions. The coordination number of the Ba cations is nine. The structural units in I-IV are connected into layers. In I, an extended system of hydrogen bonds links the layers into a framework. In II and III, the layers are linked only by weak hydrogen bonds, one bond per structural unit. In IV, ClO4- anions are bound to the Ba and Cu atoms of neighboring layers, thus serving as bridges between the layers.

  12. Quadra-Quantum Dots and Related Patterns of Quantum Dot Molecules: Basic Nanostructures for Quantum Dot Cellular Automata Application

    Directory of Open Access Journals (Sweden)

    Somsak Panyakeow

    2010-10-01

    Full Text Available Laterally close-packed quantum dots (QDs called quantum dot molecules (QDMs are grown by modified molecular beam epitaxy (MBE. Quantum dots could be aligned and cross hatched. Quantum rings (QRs created from quantum dot transformation during thin or partial capping are used as templates for the formations of bi-quantum dot molecules (Bi-QDMs and quantum dot rings (QDRs. Preferable quantum dot nanostructure for quantum computation based on quantum dot cellular automata (QCA is laterally close-packed quantum dot molecules having four quantum dots at the corners of square configuration. These four quantum dot sets are called quadra-quantum dots (QQDs. Aligned quadra-quantum dots with two electron confinements work like a wire for digital information transmission by Coulomb repulsion force, which is fast and consumes little power. Combination of quadra-quantum dots in line and their cross-over works as logic gates and memory bits. Molecular Beam Epitaxial growth technique called 'Droplet Epitaxy' has been developed for several quantum nanostructures such as quantum rings and quantum dot rings. Quantum rings are prepared by using 20 ML In-Ga (15:85 droplets deposited on a GaAs substrate at 390'C with a droplet growth rate of 1ML/s. Arsenic flux (7'8'10-6Torr is then exposed for InGaAs crystallization at 200'C for 5 min. During droplet epitaxy at a high droplet thickness and high temperature, out-diffusion from the centre of droplets occurs under anisotropic strain. This leads to quantum ring structures having non-uniform ring stripes and deep square-shaped nanoholes. Using these peculiar quantum rings as templates, four quantum dots situated at the corners of a square shape are regrown. Two of these four quantum dots are aligned either or, which are preferable crystallographic directions of quantum dot alignment in general.

  13. Crystal structure of NH4[La(SO4)2(H2O)

    OpenAIRE

    Meriem Benslimane; Yasmine Kheira Redjel; Hocine Merazig; Jean-Claude Daran

    2015-01-01

    The principal building units in the crystal structure of ammonium aquabis(sulfato)lanthanate(III) are slightly distorted SO4 tetrahedra, LaO9 polyhedra in the form of distorted tricapped trigonal prisms, and NH4+ ions. The La3+ cation is coordinated by eight O atoms from six different sulfate tetrahedra, two of which are bidentate coordinating and four monodentate, as well as one O atom from a water molecule; each sulfate anion bridges three La3+ cations. These bridging modes result in the fo...

  14. Crystal structure of NH4[La(SO4)2(H2O)

    OpenAIRE

    Benslimane, Meriem; Redjel, Yasmine Kheira; Merazig, Hocine; Daran, Jean-Claude

    2015-01-01

    The principal building units in the crystal structure of ammonium aqua­bis(sulfato)­lanthanate(III) are slightly distorted SO4 tetra­hedra, LaO9 polyhedra in the form of distorted tricapped trigonal prisms, and NH4 + ions. The La3+ cation is coordinated by eight O atoms from six different sulfate tetra­hedra, two of which are bidentate coordinating and four monodentate, as well as one O atom from a water mol­ecule; each sulfate anion bridges three La3+ cations. These bridging modes result in ...

  15. Ice Grain Collisions in Comparison: CO$_2$, H$_2$O and their Mixtures

    CERN Document Server

    Musiolik, Grzegorz; Jankowski, Tim; Wurm, Gerhard

    2016-01-01

    Collisions of ice particles play an important role in the formation of planetesimals and comets. In recent work we showed, that CO$_2$ ice behaves like silicates in collisions. The resulting assumption was that it should therefore stick less efficiently than H$_2$O ice. Within this paper a quantification of the latter is presented. We used the same experimental setup to study collisions of pure CO$_2$ ice, pure water ice and 50\\% mixtures by mass between CO$_2$ and water at 80K, 1 mbar and an average particle size of $\\sim 90 \\mu$m. The results show a strong increase of the threshold velocity between sticking and bouncing with increasing water content. This supports the idea that water ice is favorable for early growth phases of planets in a zone within the H$_2$O and the CO$_2$ iceline.

  16. The HO2 + (H2O)n + O3 reaction: an overview and recent developments*

    Science.gov (United States)

    Viegas, Luís P.; Varandas, António J. C.

    2016-03-01

    The present work is concerned with the reaction of the hydroperoxyl radical with ozone, which is key in the atmosphere. We first give a brief overview which emphasizes theoretical work developed at the authors' Group, considering not only the naked reaction (n = 0) but also the reaction with one water molecule added to the reactants (n = 1). Aiming at a broad and contextual understanding of the role of water, we have also very recently published the results of the investigation considering the addition of water dimers (n = 2) and trimers (n = 3) to the reactants. Such results are also succinctly addressed before we present our latest and unpublished research endeavors. These consist of two items: the first one addresses a new mechanistic pathway for hydrogen-abstraction in n = 2-4 cases, in which we observe a Grotthuss-like hydrogen shuttling mechanism that interconverts covalent and hydrogen bonds (water molecules are no longer spectators); the second addresses our exploratory calculations of the HO2 + O3 reaction inside a (H2O)20 water cage, where we strive to give a detailed insight of the molecular processes behind the uptake of gas-phase molecules by a water droplet. Supplementary material in the form of one zip file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2016-60733-5Contribution to the Topical Issue "Atomic Cluster Collisions (7th International Symposium)", edited by Gerardo Delgado Barrio, Andrey Solov'Yov, Pablo Villarreal, Rita Prosmiti.

  17. Separation of deuterium by H2/H2O reaction with hydrophobic platinum catalyst

    International Nuclear Information System (INIS)

    The separation performance of a trickle bed exchange column packed with a hydrophobic or waterproof catalyst is related to operating conditions such as hydrogen surface velocity, water flow rate, and temperature. The optimum carrier type and catalyst platinum content were determined. The continuous injection of roughly 103 ppm O2 regenerates the catalyst effectively. The ratio of hydrophobic catalyst to hydrophilic packing is an important factor in increasing the exchange rate in deuterium extraction

  18. Surface and Electrochemical Behavior of HSLA in Supercritical CO2-H2O Environment

    Energy Technology Data Exchange (ETDEWEB)

    M. Ziomek-Moroz; G. R. Holcomb; J. Tylczak; J. Beck; M. Fedkin; S. Lvov

    2012-01-11

    General corrosion was observed on high strength low alloy carbon steel after electrochemical impedance spectroscopy experiments (EIS) performed in H{sub 2}O saturated with CO{sub 2} at 50 C and 15.2 MPa. However, general and localized were observed on the same material surfaces after the EIS experiments performed in supercritical CO{sub 2} containing approximately 6100 ppmv H{sub 2}O at 50 C and 15.2 MPa. The general corrosion areas were uniformly covered by the FeCO{sub 3}-like phase identified by X-ray diffraction (XRD). In the area of localized corrosion, XRD also revealed FeCO{sub 3}-rich islands embedded in {alpha}-iron. The energy dispersive X-ray (EDX) analysis revealed high concentrations of iron, carbon, and oxygen in the area affected by general corrosion and in the islands formed in the area of localized corrosion. The real and imaginary impedances were lower in H{sub 2}O saturated with CO{sub 2} than those in the supercritical CO{sub 2} containing the aqueous phase indicating faster corrosion kinetics in the former.

  19. Surface Studies of HSLA Steel after Electrochemical Corrosion in Supercritical CO2-H2O Environment

    Energy Technology Data Exchange (ETDEWEB)

    Ziomek-Moroz, M. Holcomb, G. Tylczak, J Beck, J Fedkin, M. Lvov, S.

    2011-10-01

    In aqueous phase saturated with CO2, X-65 sample underwent general corrosion with formation of FeCO3. In supercritical CO2 containing water phase, two major regions are present on the sample surface after the EIS experiment. One region covered with corrosion products identified as FeCO3 and the other containing Fe, oxygen, and carbon-rich islands embedded in metal matrix identified as {alpha}-Fe. Precipitation of FeCO3 from Fe2+ and CO3 2- is responsible for formation of passive layer in oxygen-deficient, CO2 rich aqueous environment. Mechanisms of corrosion degradation occurring in supercritical CO2 as a function. Transport of supercritical CO{sub 2} is a critical element for carbon capture from fossil fuel power plants and underground sequestration. Although acceptable levels of water in supercritical CO{sub 2} (up to {approx} 5 x 10{sup -4}g/dm{sup 3}) have been established, their effects on the corrosion resistance of pipeline steels are not fully known. Moreover, the presence of SO{sub 2}, O{sub 2} impurities in addition to the water can make the fluid more corrosive and, therefore, more detrimental to service materials. Also, in this case, limited data are available on materials performance of carbon steels. to advance this knowledge, other service alloys are being investigated in the high pressure high temperature cell containing impure CO{sub 2} fluids using reliable non-destructive in-situ electrochemical methods. The electrochemical results are being augmented by a number of surface analyses of the corroded surfaces.

  20. Effect of the greenhouse gases (CO2, H2O, SO2) on Martian paleoclimate

    Science.gov (United States)

    Postawko, S. E.; Kuhn, W. R.

    1986-01-01

    There is general agreement that certain surface features on Mars are indicative of the presence of liquid water at various times in the geologic past. In particular, the valley networks are difficult to explain by a mechanism other than the flow of liquid water. It has been suggested in several studies that a thick CO2 atmosphere on Mars early in its history could have provided a greenhouse warming that would have allowed the flow of water either on the surface or just below the surface. However, this effect was examined with a detailed radiation model, and it was found that if reduced solar luminosity early in the history of the solar system is taken into account, even three bars of CO2 will not provide sufficient greeenhouse warming. The addition of water vapor and sulflur dioxide (both plausible gases that may have been emitted by Martian volcanoes) to the atmosphere also fail to warm the surface above 273 K for reduced solar luminosity conditions. The increase in temperature may be large enough, however, for the formation of these features by brines.

  1. Radiation-heterogeneous processes in the system RaSiO2+H2O

    International Nuclear Information System (INIS)

    Full text : It is known, that change of the maintenance of radium in radium silicate renders the big influence on their physical and chemical, including adsorption and catalytic properties. However, laws of influence of the maintenance of radium on radiation - heterogeneous processes of decomposition of substances in contact of radium silicates are unknown and represent great value at the decision of problems of radiation catalysis, radiating materiality and at the decision of radio environmental problems. Therefore in given article with this purpose it is investigated the kinetics of radiolytic decomposition of water in contact with radium silicate, depending on the radium maintenance at various temperatures. The received samples have been dried up in dry case under vacuum. Thus, the received results on studying of radiation-catalytic activity of various forms of radium-silicate during radiolysis o f waters (?=300) show, that high catalytic activity has radium silicate with ?=6100 b?/q?. It is established, that radium silicate depending on the maintenance of radium at ?=573 has thermo catalytic activity during decomposition of water. On the basis of these results it is possible to make the assumption, that on a surface of radium - silicate are available various thermo catalytic active centers which become more active at various temperatures. With rise in temperature during thermo catalytic decomposition participate less active centers. Thus at rise in temperature ? 573? at heterogeneous radiolysis of waters at presence of radium silicate occurs thermo catalytic and radiation-thermo catalytic decomposition of water decomposition of water

  2. Redetermination of [Pr(NO33(H2O4]·2H2O

    Directory of Open Access Journals (Sweden)

    Roel Decadt

    2012-07-01

    Full Text Available The structure of the title compound, tetraaquatris(nitrato-κ2O,O′praseodymium(III dihydrate, was redetermined. The structure models derived from the previous determinations [Rumanova et al. (1964. Kristallografiya, 9, 642–654; Fuller & Jacobson (1976. Cryst. Struct. Commun. 5, 349–352] were confirmed, but now with all H atoms unambiguously located, revealing a complex O—H...O hydrogen-bonding network, extending throughout the whole structure. In the title compound, the coordination environment of the PrIII atom can best be described as a distorted bicapped square antiprism defined by three bidentate nitrate anions and four water molecules. Additionally, two lattice water molecules are observed in the crystal packing. The title compound is isotypic with several other lanthanide-containing nitrate analogues.

  3. TES/Aura L2 H2O Nadir Special Observation V005

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  4. TES/Aura L2 H2O Nadir Special Observation V006

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  5. TES/Aura L2 H2O Nadir Special Observation V003

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  6. TES/Aura L2 H2O Nadir V003

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  7. TES/Aura L2 H2O Nadir Special Observation V004

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  8. TES/Aura L2 H2O Nadir V006

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  9. TES/Aura L2 H2O Limb V004

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  10. TES/Aura L2 H2O Nadir V005

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  11. The FORMAMIDE_2-H_2O Complex: Structure and Hydrogen Bond Cooperative Effects

    Science.gov (United States)

    Blanco, Susana; Pinacho, Pablo; Lopez, Juan Carlos

    2016-06-01

    The adduct formamide_2-H_20 has been detected in a supersonic expansion and its rotational spectra in the 5-13 GHz frequency region characterized by narrow-band molecular beam Fourier transform microwave spectroscopy (MB-FTMW). The spectrum shows the hyperfine structure due to the presence of two 14N-nuclei. This hyperfine structure has been analyzed and the determined quadrupole coupling constants together with the rotational constants have been a key for the identification of the adduct structure on the light of ab initio computations. The rotational parameters are consistent with the formation of a three body cycle thanks to the double proton acceptor/proton donor character of both formamide and water. The low value of the planar moment of inertia Pcc indicates that the heavy atom skeleton of the cluster is essentially planar. A detailed analysis of the results reveals the subtle effects of hydrogen bond cooperative effects in this system.

  12. TES/Aura L2 H2O Limb V006

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric vertical profile estimates and associated errors (diagonals and covariance matrices), along with retrieved surface temperature, cloud effective optical...

  13. Quadra-quantum Dots and Related Patterns of Quantum Dot Molecules:

    Directory of Open Access Journals (Sweden)

    Somsak Panyakeow

    2010-10-01

    Full Text Available Abstract Laterally close-packed quantum dots (QDs called quantum dot molecules (QDMs are grown by modified molecular beam epitaxy (MBE. Quantum dots could be aligned and cross hatched. Quantum rings (QRs created from quantum dot transformation during thin or partial capping are used as templates for the formations of bi-quantum dot molecules (Bi-QDMs and quantum dot rings (QDRs. Preferable quantum dot nanostructure for quantum computation based on quantum dot cellular automata (QCA is laterally close-packed quantum dot molecules having four quantum dots at the corners of square configuration. These four quantum dot sets are called quadra-quantum dots (QQDs. Aligned quadra-quantum dots with two electron confinements work like a wire for digital information transmission by Coulomb repulsion force, which is fast and consumes little power. Combination of quadra-quantum dots in line and their cross-over works as logic gates and memory bits. Molecular Beam Epitaxial growth technique called ‘‘Droplet Epitaxy” has been developed for several quantum nanostructures such as quantum rings and quantum dot rings. Quantum rings are prepared by using 20 ML In-Ga (15:85 droplets deposited on a GaAs substrate at 390°C with a droplet growth rate of 1ML/s. Arsenic flux (7–8×10-6Torr is then exposed for InGaAs crystallization at 200°C for 5 min. During droplet epitaxy at a high droplet thickness and high temperature, out-diffusion from the centre of droplets occurs under anisotropic strain. This leads to quantum ring structures having non-uniform ring stripes and deep square-shaped nanoholes. Using these peculiar quantum rings as templates, four quantum dots situated at the corners of a square shape are regrown. Two of these four quantum dots are aligned either or , which are preferable crystallographic directions of quantum dot alignment in general.

  14. Synthesis and characterization of ZnxHg1-xSeyS1-y quantum dots

    International Nuclear Information System (INIS)

    This article describes the synthesis of highly water-soluble ZnxHg1-xSeyS1-y quantum dots (QDs) in aqueous solution through a simple photo-assisted reaction between ZnSe QDs and mercury(I) nitrate dihydrate [Hg2(NO3)2.2H2O]. In order to deduce the optimal synthesis conditions, we varied several parameters, including the concentrations of mercaptosuccinic acid (MSA) and Hg2(NO3)2.2H2O, the illumination time, and the reaction temperature. When irradiated at temperatures below 80 oC, the ZnSe QDs reacted with the S2- ions formed rapidly from MSA and the Hg2+ ions formed from Hg22+ ions to form ZnxHg1-xSeyS1-y QDs through a process of photo-etching and surface combination. Under different conditions, we prepared a series of ZnxHg1-xSeyS1-y QDs that emit fluorescence at the maximum wavelengths ranging from 405 to 760 nm. Inductively coupled plasma-mass spectrometry and transmission electron microscopy/energy dispersive spectrometry revealed that the content of Hg in the ZnxHg1-xSeyS1-y QDs was greater when the synthesis was conducted at higher temperature. The Zn0.88Hg0.12Se0.44S0.56 QDs exhibit improved photostability than crude ZnSe QDs and possess long lifetimes (τ1 ∼ 38 ns and τ2 ∼ 158 ns).

  15. Об использовании оксалата железа FeC2O4·2H2O для синтеза электродного материала LiFePO4

    OpenAIRE

    Чуриков, А.; Леенсон, И.

    2012-01-01

    В обзоре обобщены литературные сведения о термическом разложении оксалата железа (II) с образованием Fe, FeO, Fe2O3, Fe3O4, Fe3Cи других продуктов. Прослежена историческая эволюция взглядов на пути и механизм термолиза оксалатов. Анализируется современное состояние проблемы с позиции использования соединения FeC2O4·2H2O для синтеза феррофосфата лития LiFePO4 многообещающего катодного материала для литий-ионных аккумуляторов....

  16. Comparative sterilization effectiveness of plasma in O2-H2O2 mixtures and ethylene oxide treatment.

    Science.gov (United States)

    Silva, J M F; Moreira, A J; Oliveira, D C; Bonato, C B; Mansano, R D; Pinto, T J A

    2007-01-01

    We investigated the influence of variable parameters of plasma sterilization and compared its effectiveness with that of ethylene oxide using a reactive ion etching plasma reactor at 13.56 MHz. Gases tested were pure oxygen and oxygen-hydrogen peroxide mixtures in 190/10, 180/20, and 160/40 sccm ratios with constant gas flow at 200 sccm, pressure at 0.100 torr, radio-frequency power at 25 W, 50 W, 100 W, and 150 W, and temperature below 60 degrees C. Ethylene oxide sterilization was performed using 450 mg/L at 55 degrees C, 60% humidity, and -0.65 and 0.60 kgf/cm2 pressure. The biological indicator was Bacillus atrophaeus ATCC 9372, with exposure times of 3 to 120 min. Observed D values were 215.91, 55.55, 9.19, and 2.98 min for pure oxygen plasma at 25 W, 50 W, 100 W, and 150 W, respectively. Oxygen-hydrogen peroxide plasma produced D values of 6.41 min (190/10), 6.47 min (180/20), and 4.02 min (160/40) at 100 W and 1.47 min (190/10), 3.11 min (180/20), and 1.94 min (160/40) at 150 W. Ethylene oxide processes resulted in a D value of 2.86 min. Scanning electron microscopy analyses showed damage to the spore cortex.

  17. CFD Convective Flow Simulation of the Varying Properties of CO2-H2O Mixtures in Geothermal Systems

    OpenAIRE

    Yousefi, S; Atrens, A. D.; Sauret, E.; M. Dahari; Hooman, K.

    2015-01-01

    Numerical simulation of a geothermal reservoir, modelled as a bottom-heated square box, filled with water-CO2 mixture is presented in this work. Furthermore, results for two limiting cases of a reservoir filled with either pure water or CO2 are presented. Effects of different parameters including CO2 concentration as well as reservoir pressure and temperature on the overall performance of the system are investigated. It has been noted that, with a fixed reservoir pressure and temperature, any...

  18. TG-FTIR measurement of CO2-H2O co-adsorption for CO2 air capture sorbent screening

    OpenAIRE

    Smal, I.M.; Yu, Q; Veneman, R.; Fränzel-Luiten, B.; Brilman, D.W.F.

    2014-01-01

    Capturing atmospheric CO2 using solid sorbents is gaining interest. As ambient air normally contains much more (up to 100 times) water than CO2, a selective sorbent is desirable as co-adsorption will most likely occur. In this study, a convenient method based on an TG-FTIR analysis system is developed and used to characterize sorbents for their water and CO2 adsorption capacity when exposed to ambient air. The method allows to determine quantitatively the co-adsorbed amounts of CO2 and water ...

  19. Iron Thin Films from Fe„CO…5 and FeCp2/H2O under Atmospheric Pressure

    OpenAIRE

    Senocq, François; Duminica, Florin-Daniel; Maury, Francis; Delsol, Thomas; Vahlas, Constantin

    2006-01-01

    Iron layers were first obtained from iron pentacarbonyl in metallorganic chemical vapor deposition MOCVD process under atmospheric pressure, in the temperature range 473–773 K, in a vertical cold wall reactor. Films of good purity were obtained with or without hydrogen as co-reactant, no chemical additives being used. The experiments showed that the velocity of the gas stream and, to a lower extent, the precursor molar fraction are the key parameters to be controlled, in order to monitor f...

  20. Ni/YSZ pattern anodes fabrication and their microstructure and electrochemical behavior changes in H2-H2O environments

    Science.gov (United States)

    Yao, W.; Croiset, E.

    2013-03-01

    An effective photolithographic process was investigated to fabricate Ni/YSZ pattern anodes using a bi-layer lift-off resist method. Suitable undercut size was found critical for successful pattern fabrication. Effects of Ni thickness, temperature and H2O content on Ni pattern microstructure were evaluated. Ni/YSZ pattern anodes with 0.5 μm thick Ni was tested in dry H2 at 550 °C without significantly changing the TPB line. Ni/YSZ pattern anodes with Ni thickness of 0.8 μm were tested at 550 °C under dry and humidified H2 (3-50% H2O) conditions without TPB line change. At 700 °C, and for 0.8 μm thick patterns, the TPB length showed pronounced change in H2 with 10-50% H2O. Significant increase in TPB length due to holes formation was observed at 800 °C with 3% and 10% H2O. Ni/YSZ pattern anodes with 1.0 μm thick Ni was stable in H2 with 3% H2O in the range 550-800 °C, with TPB line only slightly modified. However, distinct change of TPB line and Ni microstructure was observed with 10-70% H2O above 700 °C. Stabilization of the polarization resistance depends on temperature. To accelerate stabilization of the cell, pre-treatment of the cell in H2 with 3% H2O at 750 °C or 800 °C could be performed.

  1. Preparation of Pt-SDB hydrophobic catalyst used in H2-H2O isotope exchange reaction

    International Nuclear Information System (INIS)

    The preparation of Pt-SDB hydrophobic catalyst is studied, in which platinum as active metal and polystyrene divinylbenzene (SDB) as the carrier. Hydrogen isotope exchange reaction is carried out with Pt-SDB catalyst in counter-current in the trickle bed. The effect of preparing condition on the activity of catalyst is discussed. The results show that the excellent catalyst is obtained by reduced at the temperature of 200 degree C over 8 hours. Hydrophobic catalyst is high activity and stability as the amount of platinum content is 3%, the platinum can reach the economic use with the content of (1-2)%

  2. Alkaline hydrolysis of dimethyl terephthalate in the presence of [LiAl2(OH)6]Cl.2H2O

    International Nuclear Information System (INIS)

    The alkaline hydrolysis of dimethyl terephthalate (DMT) in the presence of [LiAl2(OH)6]Cl has been investigated to demonstrate a possible application of anion exchange facility of layered double hydroxides (LDHs) to control chemical reactions. The results show that (i) in the alkaline hydrolysis of DMT in the presence of [LiAl2(OH)6]Cl, most of the interlayer Cl- of [LiAl2(OH)6]Cl is quickly replaced by OH- in the alkaline solution because the LDH host favors OH- more; (ii) the alkaline hydrolysis of DMT in the presence of [LiAl2(OH)6]Cl is faster than the reaction of DMT and [LiAl2(OH)6]OH; (iii) The hydrolysis of DMT in a buffer solution of pH∼8 takes longer time to reach equilibrium than the alkaline hydrolysis of DMT in the presence of [LiAl2(OH)6]Cl. It is believed that the selective anion exchange chemistry of the LDH plays a key role in storage and controlled release of active reactant, that is, OH-, thus make the hydrolysis proceeds in a controlled way. - Graphical abstract: XRD patterns of the solid products of the alkaline hydrolysis of dimethyl terephthalate (DMT) in the presence of [LiAl2(OH)6]Cl at 70 deg. C halted at different time, which shows that [LiAl2(OH)6]Cl turns out to be [LiAl2(OH)6]OH, and [LiAl2(OH)6]2TP forms gradually. In this reaction, the alkaline hydrolysis of DMT is controlled by replacement of Cl- in [LiAl2(OH)6]Cl by OH-, and subsequent replacement of OH- in [LiAl2(OH)6]OH by terephthalate anion

  3. Highly selective catalytic reduction of NO via SO2/H2O-tolerant spinel catalysts at low temperature.

    Science.gov (United States)

    Cai, Xuanxuan; Sun, Wei; Xu, Chaochao; Cao, Limei; Yang, Ji

    2016-09-01

    Selective catalytic reduction of NO X by hydrogen (H2-SCR) in the presence of oxygen has been investigated over the NiCo2O4 and Pd-doped NiCo2O4 catalysts under varying conditions. The catalysts were prepared by a sol-gel method in the presence of oxygen within 50-350 °C and were characterized using XRD, BET, EDS, XPS, Raman, H2-TPR, and NH3-TPD analysis. The results demonstrated that the doped Pd could improve the catalyst reducibility and change the surface acidity and redox properties, resulting in a higher catalytic performance. The performance of NiCo1.95Pd0.05O4 was consistently better than that of NiCo2O4 within the 150-350 °C range at a gas hourly space velocity (GHSV) of 4800 mL g(-1) h(-1), with a feed stream containing 1070 ppm NO, 10,700 ppm H2, 2 % O2, and N2 as balance gas. The effects of GHSV, NO/H2 ratios, and O2 feed concentration on the NO conversion over the NiCo2O4 and NiCo1.95Pd0.05O4 catalysts were also investigated. The two samples similarly showed that an increase in GHSV from 4800 to 9600 mL h(-1) g(-1), the NO/H2 ratio from 1:10 to 1:1, and the O2 content from 0 to 6 % would result in a decrease in NO conversion. In addition, 2 %, 5 %, and 8 % H2O into the feed gas had a slightly negative influence on SCR activity over the two catalysts. The effect of SO2 on the SCR activity indicated that the NiCo1.95Pd0.05O4 possesses better SO2 tolerance than NiCo2O4 catalyst does. Graphical abstract The NiCo1.95Pd0.05O4 catalyst achieved over 90 % NO conversion with N2 selectivity of 100 % in the 200∼250 °C range than the maximum 40.5 % NO conversion over NiCo2O4 with N2 selectivity of approximately 80 % in 350 °C. PMID:27301438

  4. Comparative sterilization effectiveness of plasma in O2-H2O2 mixtures and ethylene oxide treatment.

    Science.gov (United States)

    Silva, J M F; Moreira, A J; Oliveira, D C; Bonato, C B; Mansano, R D; Pinto, T J A

    2007-01-01

    We investigated the influence of variable parameters of plasma sterilization and compared its effectiveness with that of ethylene oxide using a reactive ion etching plasma reactor at 13.56 MHz. Gases tested were pure oxygen and oxygen-hydrogen peroxide mixtures in 190/10, 180/20, and 160/40 sccm ratios with constant gas flow at 200 sccm, pressure at 0.100 torr, radio-frequency power at 25 W, 50 W, 100 W, and 150 W, and temperature below 60 degrees C. Ethylene oxide sterilization was performed using 450 mg/L at 55 degrees C, 60% humidity, and -0.65 and 0.60 kgf/cm2 pressure. The biological indicator was Bacillus atrophaeus ATCC 9372, with exposure times of 3 to 120 min. Observed D values were 215.91, 55.55, 9.19, and 2.98 min for pure oxygen plasma at 25 W, 50 W, 100 W, and 150 W, respectively. Oxygen-hydrogen peroxide plasma produced D values of 6.41 min (190/10), 6.47 min (180/20), and 4.02 min (160/40) at 100 W and 1.47 min (190/10), 3.11 min (180/20), and 1.94 min (160/40) at 150 W. Ethylene oxide processes resulted in a D value of 2.86 min. Scanning electron microscopy analyses showed damage to the spore cortex. PMID:17722487

  5. CFD Convective Flow Simulation of the Varying Properties of CO2-H2O Mixtures in Geothermal Systems

    Directory of Open Access Journals (Sweden)

    S. Yousefi

    2015-01-01

    Full Text Available Numerical simulation of a geothermal reservoir, modelled as a bottom-heated square box, filled with water-CO2 mixture is presented in this work. Furthermore, results for two limiting cases of a reservoir filled with either pure water or CO2 are presented. Effects of different parameters including CO2 concentration as well as reservoir pressure and temperature on the overall performance of the system are investigated. It has been noted that, with a fixed reservoir pressure and temperature, any increase in CO2 concentration leads to better performance, that is, stronger convection and higher heat transfer rates. With a fixed CO2 concentration, however, the reservoir pressure and temperature can significantly affect the overall heat transfer and flow rate from the reservoir. Details of such variations are documented and discussed in the present paper.

  6. CFD convective flow simulation of the varying properties of CO2-H2O mixtures in geothermal systems.

    Science.gov (United States)

    Yousefi, S; Atrens, A D; Sauret, E; Dahari, M; Hooman, K

    2015-01-01

    Numerical simulation of a geothermal reservoir, modelled as a bottom-heated square box, filled with water-CO2 mixture is presented in this work. Furthermore, results for two limiting cases of a reservoir filled with either pure water or CO2 are presented. Effects of different parameters including CO2 concentration as well as reservoir pressure and temperature on the overall performance of the system are investigated. It has been noted that, with a fixed reservoir pressure and temperature, any increase in CO2 concentration leads to better performance, that is, stronger convection and higher heat transfer rates. With a fixed CO2 concentration, however, the reservoir pressure and temperature can significantly affect the overall heat transfer and flow rate from the reservoir. Details of such variations are documented and discussed in the present paper. PMID:25879074

  7. The reaction of uranium in the U-O2-H2O and U-H2O systems

    International Nuclear Information System (INIS)

    The reaction of uranium in dry air, moist air and oxygen free moisture has been studied thermogravimetrically over the temperature range 105-3250C and at water vapour pressures up to 100 kPa. It has been shown that in dry air the kinetics are complex and appear to result from parallel reactions involving both parabolic and linear rate laws. In oxygen free moisture, linear kinetics were obeyed and a near stoichiometric UO2 reaction product was formed. Oxygen markedly inhibited the moisture reaction at the lower temperatures in the range examined but the degree of inhibition, as shown by weight gain measurements, decreased with increasing temperature such that, at the higher temperatures, there was little difference in reaction rates. At all temperatures, the production of hydrogen was markedly inhibited by the presence of air suggesting that the principal reaction was with free oxygen. However in moist conditions the reaction rate exhibited a dependency on the water vapour pressure according to k α psup(n) where n ∼ 0.3 in air and ∼ 0.5 in oxygen free conditions. The mechanism of the oxidation reaction is discussed. (author)

  8. Atmospheric isoprene ozonolysis: impacts of stabilized Criegee intermediate reactions with SO2, H2O and dimethyl sulfide

    Directory of Open Access Journals (Sweden)

    M. J. Newland

    2015-03-01

    Full Text Available Isoprene is the dominant global biogenic volatile organic compound (VOC emission. Reactions of isoprene with ozone are known to form stabilised Criegee intermediates (SCIs, which have recently been shown to be potentially important oxidants for SO2 and NO2 in the atmosphere; however the significance of this chemistry for SO2 processing (affecting sulfate aerosol and NO2 processing (affecting NOx levels depends critically upon the fate of the SCI with respect to reaction with water and decomposition. Here, we have investigated the removal of SO2 in the presence of isoprene and ozone, as a function of humidity, under atmospheric boundary layer conditions. The SO2 removal displays a clear dependence on relative humidity, confirming a significant reaction for isoprene derived SCI with H2O. Under excess SO2 conditions, the total isoprene ozonolysis SCI yield was calculated to be 0.56 (±0.03. The observed SO2 removal kinetics are consistent with a relative rate constant, k(SCI + H2O/k(SCI + SO2, of 5.4 (±0.8 × 10−5 for isoprene derived SCI. The relative rate constant for k(SCI decomposition/k(SCI + SO2 is 8.4 (±5.0 × 1010 cm−3. Uncertainties are ±2σ and represent combined systematic and precision components. These kinetic parameters are based on the simplification that a single SCI species is formed in isoprene ozonolysis, an approximation which describes the results well across the full range of experimental conditions. Our data indicate that isoprene-derived SCIs are unlikely to make a substantial contribution to gas-phase SO2 oxidation in the troposphere. We also present results from an analogous set of experiments, which show a clear dependence of SO2 removal in the isoprene-ozone system as a function of dimethyl sulfide concentration. We propose that this behaviour arises from a rapid reaction between isoprene-derived SCI and DMS; the observed SO2 removal kinetics are consistent with a relative rate constant, k(SCI + DMS/k(SCI + SO2, of 4.1 (±2.2. This result suggests that SCIs may contribute to the oxidation of DMS in the atmosphere and that this process could therefore influence new particle formation in regions impacted by emissions of unsaturated hydrocarbons and DMS.

  9. Effect of Kovar alloy oxidized in simulated N2/H2O atmosphere on its sealing with glass

    Institute of Scientific and Technical Information of China (English)

    Dawei Luo; Wenbo Leng; Zhuoshen Shen

    2008-01-01

    The effect of Kovar alloy oxidized in simulated field atmosphere on its sealing with glass was studied in this article. After Kovar plates and pins were preoxidized in N2 with 0℃, 10℃ and 20℃ dew points at 1000℃ for different times, Fe3O4 and Fe2O3 existed in the oxidation products on Kovar surface, and the quantity of Fe2O3 increased with increasing dew point and oxidation time.Then they were sealed with borosilicate glass insulator at 1030℃ for 20 min. The results indicated that the type and quantity of oxidation products would directly influence the quality of glass-to-metal seals. With the increase of oxidation products, gas bubbles in the glass insulator were more serious, the climbing height of glass along the pins was higher, and corrosion of Kovar pins caused from the molten glass was transformed from uniform to the localized.

  10. Formation and ordering of epitaxial quantum dots

    Science.gov (United States)

    Atkinson, Paola; Schmidt, Oliver G.; Bremner, Stephen P.; Ritchie, David A.

    2008-10-01

    Single quantum dots (QDs) have great potential as building blocks for quantum information processing devices. However, one of the major difficulties in the fabrication of such devices is the placement of a single dot at a pre-determined position in the device structure, for example, in the centre of a photonic cavity. In this article we review some recent investigations in the site-controlled growth of InAs QDs on GaAs by molecular beam epitaxy. The method we use is ex-situ patterning of the GaAs substrate by electron beam lithography and conventional wet or dry etching techniques to form shallow pits in the surface which then determine the nucleation site of an InAs dot. This method is easily scalable and can be incorporated with marker structures to enable simple post-growth lithographic alignment of devices to each site-controlled dot. We demonstrate good site-control for arrays with up to 10 micron spacing between patterned sites, with no dots nucleating between the sites. We discuss the mechanism and the effect of pattern size, InAs deposition amount and growth conditions on this site-control method. Finally we discuss the photoluminescence from these dots and highlight the remaining challenges for this technique. To cite this article: P. Atkinson et al., C. R. Physique 9 (2008).

  11. CMS Centre at CERN

    CERN Multimedia

    2007-01-01

    A new "CMS Centre" is being established on the CERN Meyrin site by the CMS collaboration. It will be a focal point for communications, where physicists will work together on data quality monitoring, detector calibration, offline analysis of physics events, and CMS computing operations. Construction of the CMS Centre begins in the historic Proton Synchrotron (PS) control room. The historic Proton Synchrotron (PS) control room, Opened by Niels Bohr in 1960, will be reused by CMS to built its control centre. TThe LHC@FNAL Centre, in operation at Fermilab in the US, will work very closely with the CMS Centre, as well as the CERN Control Centre. (Photo Fermilab)The historic Proton Synchrotron (PS) control room is about to start a new life. Opened by Niels Bohr in 1960, the room will be reused by CMS to built its control centre. When finished, it will resemble the CERN Contro...

  12. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    1999-01-01

    Semiconductor quantum dots ("solid state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...

  13. Client Centred Desing

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Nielsen, Janni; Levinsen, Karin

    2008-01-01

    In this paper we argue for the use of Client Centred preparation phases when designing complex systems. Through Client Centred Design human computer interaction can extend the focus on end-users to alse encompass the client's needs, context and resources.......In this paper we argue for the use of Client Centred preparation phases when designing complex systems. Through Client Centred Design human computer interaction can extend the focus on end-users to alse encompass the client's needs, context and resources....

  14. Canadian Irradiation Centre

    International Nuclear Information System (INIS)

    The Canadian Irradiation Centre is a non-profit cooperative project between Atomic Energy of Canada Limited, Radiochemical Company and Universite du Quebec, Institut Armand-Frappier, Centre for Applied Research in Food Science. The Centre's objectives are to develop, demonstrate and promote Canada's radiation processing technology and its applications by conducting applied research; training technical, professional and scientific personnel; educating industry and government; demonstrating operational and scientific procedures; developing processing procedures and standards, and performing product and market acceptance trials. This pamphlet outlines the history of radoation technology and the services offered by the Canadian Irradiation Centre

  15. Improved operability of the CANDU 9 control centre

    Energy Technology Data Exchange (ETDEWEB)

    Macbeth, M. J.; Webster, A. [Atomic Energy of Canada Limited, Saskatoon (Canada)

    1996-04-15

    The next generation CANDU nuclear power plant being designed by AECL is the 900 MWe class CANDU 9 station. It is based upon the Darlington CANDU station design which is among the world leaders in capacity factor with low Operation, Maintenance and Administration (OM and A) costs. This Control Centre design includes the proven functionality of existing CANDU control centres (including the Wolsong 2,3, and 4 control centre improvements, such as the Emergency Core Cooling panels), the characteristics identified by systematic design with human factors analysis of operations requirements and the advanced features needed to improve station operability which is made possible by the application of new technology. The CANDU 9 Control Centre provides plant staff with an improved operability capability due to the combination of proveness, systematic design with human factors engineering and enhanced operating features. Significant features which contribute to this improved operability include: {center_dot} Standard NSP, BOP and F/H panels with controls and indicators integrated by a standard display/presentation philosophy. {center_dot} Common plant parameter signal database for extensive monitoring, checking, display and annunciation. {center_dot} Powerful annunciation system allowing alarm filtering, prioritizing and interrogation to enhance staff recognition of events, plant state and required corrective procedural actions. {center_dot} The use of an overview display to present immediate and uncomplicated plant status information to facilitate operator awareness of unit status in a highly readable and recognizable format. {center_dot} Extensive cross checking of similar process parameters amongst themselves, with the counterpart safety system parameters and as well as with 'signature' values obtained from known steady state conditions. {center_dot} Powerful calculation capabilities, using the plant wide database, providing immediate recognizable and readable and

  16. The IGU Knowledge Centre

    NARCIS (Netherlands)

    Huizing, Bernardus

    2005-01-01

    This article describes an innovative service for members of the International Gas Union - IGU. The IGU Knowledge Centre provides members with relevant information and data. In this article is described why, how and where.

  17. CENTRE FOR GEOMETRICAL METROLOGY

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

    The objective of this Annual Report is to give a general introduction to CGM as well as to give an account of the tasks carried out using the facilities of CGM's Instrument Centre during 1998 and 1999....

  18. Virtual particle therapy centre

    CERN Multimedia

    2015-01-01

    Particle therapy is an advanced technique of cancer radiation therapy, using protons or other ions to target the cancerous mass. This advanced technique requires a multi-disciplinary team working in a specialised centre. 3D animation: Nymus3D

  19. The Bruce Energy Centre

    International Nuclear Information System (INIS)

    The Bruce Energy Centre Development Corporation is a joint venture of the Ontario Energy Corporation and 6 private companies formed to market surplus steam from the Bruce Nuclear Power Development. The corporation will also sell or lease land near Bruce NPD. The Bruce Energy Centre has an energy output of 900 BTU per day per dollar invested. Potential customers include greenhouse operators, aquaculturalists, food and beverage manufacturers, and traditional manufacturers

  20. The ideal Atomic Centre

    International Nuclear Information System (INIS)

    The author presents considerations which should prove to be of interest to all those who have to design, to construct and to operate a nuclear research centre. A large number of the ideas presented can also be applied to non-nuclear scientific research centres. In his report the author reviews: various problems with which the constructor is faced: ground-plan, infrastructure, buildings and the large units of scientific equipment in the centre, and those problems facing the director: maintenance, production, supplies, security. The author stresses the relationship which ought to exist between the research workers and the management. With this aim in view he proposes the creation of National School for Administration in Research which would train administrative executives for public or private organisations; they would be specialised in the fields of fundamental or applied research. (author)

  1. Self-assembly of extended structures through non-coordination intermolecular forces: Synthesis, crystal structures, and properties of metal complexes with 5-methyl-2-pyrazinecarboxylate

    NARCIS (Netherlands)

    Tanase, S.; Son, M. van; Albada, G.A. van; Gelder, R. de; Bouwman, E.; Reedijk, J.

    2006-01-01

    Three new complexes of 5-methyl-2-pyrazinecarboxylate (Hmpca) with cobalt(II), [Co(mpca)(2)(H2O)(2)], nickel(II), [Ni(mpca)(2)(H2O)(2)] and iron(III) [Fe(mpca)(2)(OH)](2) center dot 2H(2)O, have been synthesized and characterized by spectroscopic techniques, X-ray crystallography and low-temperature

  2. Lidar Calibration Centre

    Science.gov (United States)

    Pappalardo, Gelsomina; Freudenthaler, Volker; Nicolae, Doina; Mona, Lucia; Belegante, Livio; D'Amico, Giuseppe

    2016-06-01

    This paper presents the newly established Lidar Calibration Centre, a distributed infrastructure in Europe, whose goal is to offer services for complete characterization and calibration of lidars and ceilometers. Mobile reference lidars, laboratories for testing and characterization of optics and electronics, facilities for inspection and debugging of instruments, as well as for training in good practices are open to users from the scientific community, operational services and private sector. The Lidar Calibration Centre offers support for trans-national access through the EC HORIZON2020 project ACTRIS-2.

  3. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    Semiconductor quantum dots ("solid-state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...

  4. Quantum Dots: Theory

    Energy Technology Data Exchange (ETDEWEB)

    Vukmirovic, Nenad; Wang, Lin-Wang

    2009-11-10

    This review covers the description of the methodologies typically used for the calculation of the electronic structure of self-assembled and colloidal quantum dots. These are illustrated by the results of their application to a selected set of physical effects in quantum dots.

  5. Ultrasmall silicon quantum dots

    NARCIS (Netherlands)

    Zwanenburg, F.A.; Van Loon, A.A.; Steele, G.A.; Rijmenam, C.E.W.M.; Balder, T.; Fang, Y.; Lieber, C.M.; Kouwenhoven, L.P.

    2009-01-01

    We report the realization of extremely small single quantum dots in p-type silicon nanowires, defined by Schottky tunnel barriers with Ni and NiSi contacts. Despite their ultrasmall size the NiSi–Si–NiSi nanowire quantum dots readily allow spectroscopy of at least ten consecutive holes, and addition

  6. International research centre launched

    International Nuclear Information System (INIS)

    Full text: The first scientific research and educational institution to be set up on a completely international basis was officially inaugurated in Trieste on 5 October 1964 by the Director General of IAEA, Dr. Sigvard Eklund, when he opened the first seminar of the International Centre for Theoretical Physics. As evidence of the international nature of the institution he noted that the scientists who would work and teach there during the first year represented sixteen different countries. By the end of 1964, the Centre building was nearing completion and three of the five floors were occupied. A successful symposium had been held on the subject of plasma physics, and a score of professors and fellows were at work, from Bulgaria, Czechoslovakia, Greece, India, Japan, Jordan, the Netherlands, Norway, Pakistan, Poland, the United Kingdom, and the United States. A dozen scientific papers had been issued as preprints. The main purpose of the Centre is to foster the advancement of theoretical physics through training and research; at first the chief subject will be high-energy and elementary particle physics. Plasma physics, low energy physics and solid-state physics will also be dealt with. Special attention is paid to the needs of the developing countries. Of the 25 fellows selected for the academic year 1964-65, more than half are from South America, Africa and Asia. In conjunction with the Research Centre, there is an Advanced School for theoretical Physics to provide graduate training for fellows who need such preparation before they embark upon research. The Centre works under the guidance of a Scientific Council comprising the president, Prof. M. Sandoval-Vallarta (Nuclear Energy Commission of Mexico); Prof. A. Abragam (Saclay, France); Prof. R. Oppenheimer (Institute for Advanced Study, Princeton, USA); Dr. V. Soloviev (Dubna, USSR); Prof V.F. Weiskopf (Director General, CERN) ; Prof Abdus Salam (Imperial College, London) ; Prof. P. Budini (University of Trieste

  7. Quantum dot density studies for quantum dot intermediate band solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Thomassen, Sedsel Fretheim; Zhou, Dayong; Vitelli, Stefano; Mayani, Maryam Gholami; Fimland, Bjoern-Ove; Reenaas, Turid Worren

    2010-07-01

    Quantum dots (QDs) have been an active area of research for many years and have been implemented in several applications, such as lasers and detectors. During the last years, some attempts have been made to increase the absorption and efficiency of solar cells by inserting QDs into the intrinsic region of pin solar cells. So far, these attempts have been successful in increasing the absorption, but not the cell efficiency. There are probably several reasons for this lack of efficiency increase, but we believe that one important reason is the low density of the implemented QDs. In this work, samples of single layer InAs QDs on n-GaAs(001) substrates have been grown by molecular beam epitaxy (MBE) and we have performed a systematic study of how deposition parameters affect the QD density. The aim is to achieve densities > 1011 cm-2. The nominal substrate temperature (360 - 500 deg. C), the InAs growth rate (0.085 - 1 ML/s) and thickness (2.0 - 2.8 ML) have been varied in a systematic way for two different deposition methods of InAs, i.e. continuous deposition or deposition with interruptions. In addition, we have for the continuous growth samples also varied the As-flux (0.5 - 6 centre dot10-6 torr). Scanning electron microscopy (SEM) has been the main characterization method to determine quantum dot sizes and densities, and atomic force microscopy (AFM) has been used for evaluation of the quantum dot heights. We find that the QD density increases with reduced growth temperature and that it is higher for samples grown continuously than for samples grown with growth interruptions. The homogeneity is also strongly affected by temperature, InAs deposition method and the As-flux. We have observed QD densities as high as 2.5 centre dot1011 cm-2 for the samples grown at the lowest growth temperatures. (Author)

  8. Academic Drug Discovery Centres

    DEFF Research Database (Denmark)

    Kirkegaard, Henriette Schultz; Valentin, Finn

    2014-01-01

    Academic drug discovery centres (ADDCs) are seen as one of the solutions to fill the innovation gap in early drug discovery, which has proven challenging for previous organisational models. Prior studies of ADDCs have identified the need to analyse them from the angle of their economic...

  9. Implementing Responsibility Centre Budgeting

    Science.gov (United States)

    Vonasek, Joseph

    2011-01-01

    Recently, institutes of higher education (universities) have shown a renewed interest in organisational structures and operating methodologies that generate productivity and innovation; responsibility centre budgeting (RCB) is one such process. This paper describes the underlying principles constituting RCB, its origin and structural elements, and…

  10. ATLAS Visitors Centre

    CERN Multimedia

    claudia Marcelloni

    2009-01-01

    ATLAS Visitors Centre has opened its shiny new doors to the public. Officially launched on Monday February 23rd, 2009, the permanent exhibition at Point 1 was conceived as a tour resource for ATLAS guides, and as a way to preserve the public’s opportunity to get a close-up look at the experiment in action when the cavern is sealed.

  11. Elderly Care Centre

    Science.gov (United States)

    Wagiman, Aliani; Haja Bava Mohidin, Hazrina; Ismail, Alice Sabrina

    2016-02-01

    The demand for elderly centre has increased tremendously abreast with the world demographic change as the number of senior citizens rose in the 21st century. This has become one of the most crucial problems of today's era. As the world progress into modernity, more and more people are occupied with daily work causing the senior citizens to lose the care that they actually need. This paper seeks to elucidate the best possible design of an elderly care centre with new approach in order to provide the best service for them by analysing their needs and suitable activities that could elevate their quality of life. All these findings will then be incorporated into design solutions so as to enhance the living environment for the elderly especially in Malaysian context.

  12. Graphene quantum dots

    CERN Document Server

    Güçlü, Alev Devrim; Korkusinski, Marek; Hawrylak, Pawel

    2014-01-01

    This book reflects the current status of theoretical and experimental research of graphene based nanostructures, in particular quantum dots, at a level accessible to young researchers, graduate students, experimentalists and theorists. It presents the current state of research of graphene quantum dots, a single or few monolayer thick islands of graphene. It introduces the reader to the electronic and optical properties of graphite, intercalated graphite and graphene, including Dirac fermions, Berry's phase associated with sublattices and valley degeneracy, covers single particle properties of

  13. Tele-centres in Ghana

    DEFF Research Database (Denmark)

    Falch, Morten

    2004-01-01

    Tele-centres offer a low cost opportunity for the many who cannot afford their own phone or Internet connection. This paper presents a field study of tele-centres in Ghana and analyses how they contribute to universal access.......Tele-centres offer a low cost opportunity for the many who cannot afford their own phone or Internet connection. This paper presents a field study of tele-centres in Ghana and analyses how they contribute to universal access....

  14. Treatment Outcomes of Patients Placed on Treatment Under Directly Observed Therapy Short-Course (Dots)

    OpenAIRE

    Kaur Gurpreet; Goel N; Kumar Dinesh; Janmeja A; Swami H; Kalia Meenu

    2008-01-01

    Background : Tuberculosis continues to be a pressing health problem in India. The Revised National Tuberculosis Programme (RNTCP), an application of Directly Observed Treatment Short-course (DOTS) in India, launched in 1997 needs contin-uous evaluation. Objective : To study the outcomes of treatment among the patients put on DOTS under RNTCP in Chandigarh, UT. Material & Methods : A Longitudi-nal study was conducted during 2004-2005 in 13 Microscopic centres (MC′s) spread over...

  15. Binding Energies of Negatively Charged Donors in a Gaussian Potential Quantum Dot

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2005-01-01

    @@ We investigate a negatively charged donor centre (D-) trapped by a quantum dot, which is subjected to a Gaussian potential confinement. Calculations are carried out by using the method of numerical diagonalization of Hamiltonian within the effective-mass approximation. The dependence of the ground state of the negatively charged donor on the dot size and the potential depth is studied. The same calculations performed with the parabolic approximation of the Gaussian potential lead to the results that are qualitatively and quantitatively different.

  16. Transition energies and magnetic properties of a neutral donor complex in a Gaussian GaAs quantum dot

    Science.gov (United States)

    Boda, Aalu; Chatterjee, Ashok

    2016-09-01

    The problem of a neutral hydrogenic donor (D0) centre located at the centre of a GaAs quantum dot with Gaussian confinement is studied in the presence of an external magnetic field. The ground and the first excited state energies and the corresponding binding energies are obtained as functions of the potential strength, quantum dot radius and the magnetic field using a variational method. It is suggested that the first excited state of the D0 centre is bound for sufficiently strong confinement potential. The 1 s - 2p- transition energy and the magnetic susceptibilities for the ground and the first excited states are also determined.

  17. DGNB certified Healthcare Centres

    DEFF Research Database (Denmark)

    Brunsgaard, Camilla; Larsen, Tine Steen

    2015-01-01

    for sustainability and wants a certification. This research investigates the decision‐making and design process (DMaDP) behind four DGNB certified Healthcare Centres (HCC) in Northern Jutland in Denmark. In general, knowledge about the DMaDP is important. However it is important to know what part DGNB plays...... a dialog about DGNB and energy concept is important even before anyone start sketching. Experiences with the different approaches will be further outlined in the paper.Future research has the intention to collect further knowledge about DGNB and DMaDP in practise. This project was limited to Healthcare...

  18. Centre liikekeskuksen digital signage

    OpenAIRE

    Bincl, Suzana

    2015-01-01

    Opinnäytetyöni tarkastelee digital signagen suunnittelussa huomioitavia tekijöitä ja sen arvoa markkinointikanavana. Työ on toteutettu tilaustyönä Lappeenrantalaiselle mainostoimisto Mediakolmiolle. Työ sisältää teoriaosuuden lisäksi sisältösuunnitelman rakenteilla olevalle Centre liikekeskukselle. Tavoitteena oli luoda liikekeskukselle sen brändiä tukeva digital signage konsepti. Työ ei sisällä valmista tuotetta, vaan se toimii ehdotelmana myöhemmin alkavalle tuotanno...

  19. Town Centre Redevelopment Strategies

    DEFF Research Database (Denmark)

    Vagnby, Bo Hellisen

    urban planning and design strategieswhich have been practised in most of the larger Danish towns: pedestrian streets, shopping centres, preservation of historic features, waterfronts, concentration of offices, conference and sports facilities, improvement og traffic and transport conditions as well...... as slum clearence and urban renewal. To a certain extent parallels are drawn to international experiences, especially where these are of such a nature that they can be assumed transferred to Danish connctions. Conclusively, the strategies are discussed in the light of the turn of Danish urban planning...

  20. A novel POSS-coated quantum dot for biological application

    OpenAIRE

    Rizvi SB; Yildirimer L; Ghaderi S; Ramesh B; Seifalian AM; Keshtgar M

    2012-01-01

    Sarwat B Rizvi,1 Lara Yildirimer,1 Shirin Ghaderi,1 Bala Ramesh,1 Alexander M Seifalian,1,2 Mo Keshtgar1,21UCL Centre for Nanotechnology and Regenerative Medicine, Division of Surgery and Interventional Science, University College London, United Kingdom; 2Royal Free Hampstead NHS Trust Hospital, London, United KingdomAbstract: Quantum dots (QDs) are fluorescent semiconductor nanocrystals that have the potential for major advancements in the field of nanomedicine through their unique photophys...

  1. Formulating CdSe quantum dots for white light-emitting diodes with high color rendering index

    International Nuclear Information System (INIS)

    Generation of white light using CdSe quantum dots (QDs) alone presents exciting possibilities for solid state lighting technology. In this work, Cd(Ac)2·2H2O and Na2SeSO3 are used as precursors to synthesize CdSe-QDs with an average diameter ranging from 2.77 to 4.65 nm at the low temperature from 60 to 180 °C. Smaller CdSe-QDs with an average diameter of 2.29 nm are got by an oxidation etching process using H2O2 as oxidant. The structural and optical properties of these QDs are investigated and proper formulation of CdSe QDs with various sizes is carefully designed to achieve white light with a high color rendering index (CRI). It is observed for the first time that the as-prepared white light-emitting diodes from single CdSe-QDs show the Commission Inernationale del’Eclairage coordinate (CIE) of (0.30,0.34) very close to that (0.33,0.33) of pure white light and a high CRI of 84. Owing to these advantages, the as-prepared white light-emitting diodes from a single compound are promising for lighting applications. - Highlights: • CdSe-quantum dots (QDs) with a continuously changing size from 2.31 to 4.74 nm are prepared. • The obtained CdSe-QDs emit lights with tunable colors in the whole visible range. • The obtained mixture sample generates white light with a high color rendering index of 84. • The sample yields white light with the CIE coordinate (0.30, 0.34) very close to that of pure white light

  2. Computational, electrochemical, and spectroscopic studies of two mononuclear cobaloximes: the influence of an axial pyridine and solvent on the redox behaviour and evidence for pyridine coordination to cobalt(i) and cobalt(ii) metal centres.

    Science.gov (United States)

    Lawrence, Mark A W; Celestine, Michael J; Artis, Edward T; Joseph, Lorne S; Esquivel, Deisy L; Ledbetter, Abram J; Cropek, Donald M; Jarrett, William L; Bayse, Craig A; Brewer, Matthew I; Holder, Alvin A

    2016-06-21

    [Co(dmgBF2)2(H2O)2] (where dmgBF2 = difluoroboryldimethylglyoximato) was used to synthesize [Co(dmgBF2)2(H2O)(py)]·0.5(CH3)2CO (where py = pyridine) in acetone. The formulation of complex was confirmed by elemental analysis, high resolution MS, and various spectroscopic techniques. The complex [Co(dmgBF2)2(solv)(py)] (where solv = solvent) was readily formed in situ upon the addition of pyridine to complex . A spectrophotometric titration involving complex and pyridine proved the formation of such a species, with formation constants, log K = 5.5, 5.1, 5.0, 4.4, and 3.1 in 2-butanone, dichloromethane, acetone, 1,2-difluorobenzene/acetone (4 : 1, v/v), and acetonitrile, respectively, at 20 °C. In strongly coordinating solvents, such as acetonitrile, the lower magnitude of K along with cyclic voltammetry, NMR, and UV-visible spectroscopic measurements indicated extensive dissociation of the axial pyridine. In strongly coordinating solvents, [Co(dmgBF2)2(solv)(py)] can only be distinguished from [Co(dmgBF2)2(solv)2] upon addition of an excess of pyridine, however, in weakly coordinating solvents the distinctions were apparent without the need for excess pyridine. The coordination of pyridine to the cobalt(ii) centre diminished the peak current at the Epc value of the Co(I/0) redox couple, which was indicative of the relative position of the reaction equilibrium. Herein we report the first experimental and theoretical (59)Co NMR spectroscopic data for the formation of Co(i) species of reduced cobaloximes in the presence and absence of py (and its derivatives) in CD3CN. From spectroelectrochemical studies, it was found that pyridine coordination to a cobalt(i) metal centre is more favourable than coordination to a cobalt(ii) metal centre as evident by the larger formation constant, log K = 4.6 versus 3.1, respectively, in acetonitrile at 20 °C. The electrosynthesis of hydrogen by complexes and in various solvents demonstrated the dramatic effects of the axial

  3. [The primary healthcare centres].

    Science.gov (United States)

    Brambilla, Antonio; Maciocco, Gavino

    2014-04-01

    The central attributes of primary care are: first contact (accessibility), longitudinality (person- focused preventive and curative care overtime), patient-oriented comprehensiveness and coordination (including navigation towards secondary and tertiary care). Besides taking care of the needs of the individuals, primary health care teams are also looking at the community, especially when addressing social determinants of health. The rationale for the benefits for primary care for health has been found in: 1) greater access to needed services; 2) better quality of care; 3) a greater focus on prevention; 4) early management of health problems; 5) organizing and delivering high quality care for chronic non-communicable diseases. This paper describes the role of primary healthcare centres in strengthening community primary services and in reducing health inequalities. Furthemore, the experiences of Regional Health Services from Tuscany and Emilia-Romagna are discussed, with a brief overview of the literature. PMID:24770539

  4. Quantum dot solar cells

    CERN Document Server

    Wu, Jiang

    2013-01-01

    The third generation of solar cells includes those based on semiconductor quantum dots. This sophisticated technology applies nanotechnology and quantum mechanics theory to enhance the performance of ordinary solar cells. Although a practical application of quantum dot solar cells has yet to be achieved, a large number of theoretical calculations and experimental studies have confirmed the potential for meeting the requirement for ultra-high conversion efficiency. In this book, high-profile scientists have contributed tutorial chapters that outline the methods used in and the results of variou

  5. Experiences of Telebased Information Centres

    DEFF Research Database (Denmark)

    Falch, Morten

    1999-01-01

    Tele-based information community centres or just tele-centres have been seen as the killer application to empower local communities in developed and developing countries to meet the challenges of the information society. This paper will present a number of models for introducing such centres and ...... and discuss the different models and national strategies used for setting up tele-based information in relation to the Ghana experience.......Tele-based information community centres or just tele-centres have been seen as the killer application to empower local communities in developed and developing countries to meet the challenges of the information society. This paper will present a number of models for introducing such centres...

  6. Update on System Coordination Centre

    Energy Technology Data Exchange (ETDEWEB)

    Stangl, W. [Power Pool of Alberta, Calgary, AB (Canada)

    1998-07-01

    The new System Coordination Centre at the Power Pool of Alberta was designed to meet the unique requirements of Alberta`s electric industry under the new regulatory regime. Development of the Centre, key provisions of the energy management system (EMS) are highlighted. The centre will provide an energy management system for the Pool`s system controller function and interface with the Power Pool Administrator`s market functions and the operations of the Transmission Administrator. System controllers are expected to be operating from the new location by the end of 1998. Unique EMS features of the centre include: (1) real-time management of energy market and network operations using diverse SCADA/EMS, (2) inter-control centre protocol used to accommodate the unique participant information requirements, and (3) special custom applications. The Centre is expected to be fully functioning by July 1999. 1 fig.

  7. Carbon nanotube quantum dots

    NARCIS (Netherlands)

    Sapmaz, S.

    2006-01-01

    Low temperature electron transport measurements on individual single wall carbon nanotubes are described in this thesis. Carbon nanotubes are small hollow cylinders made entirely out of carbon atoms. At low temperatures (below ~10 K) finite length nanotubes form quantum dots. Because of its small si

  8. Colloidal Double Quantum Dots.

    Science.gov (United States)

    Teitelboim, Ayelet; Meir, Noga; Kazes, Miri; Oron, Dan

    2016-05-17

    Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole-dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single photon

  9. Electron correlations in quantum dots

    CERN Document Server

    Tipton, D L J

    2001-01-01

    Quantum dot structures confine electrons in a small region of space. Some properties of semiconductor quantum dots, such as the discrete energy levels and shell filling effects visible in addition spectra, have analogies to those of atoms and indeed dots are sometimes referred to as 'artificial atoms'. However, atoms and dots show some fundamental differences due to electron correlations. For real atoms, the kinetic energy of electrons dominates over their mutual Coulomb repulsion energy and for this reason the independent electron approximation works well. For quantum dots the confining potential may be shallower than that of real atoms leading to lower electron densities and a dominance of mutual Coulomb repulsion over kinetic energy. In this strongly correlated regime the independent electron picture leads to qualitatively incorrect results. This thesis concentrates on few-electron quantum dots in the strongly correlated regime both for quasi-one-dimensional and two-dimensional dots in a square confining p...

  10. Fuzzy Dot Structure of BG-algebras

    OpenAIRE

    Tapan Senapati; Monoranjan Bhowmik; Madhumangal Pal

    2014-01-01

    In this paper, the notions of fuzzy dot subalgebras is introduced together with fuzzy normal dot subalgebras and fuzzy dot ideals of BG-algebras. The homomorphic image and inverse image are investigated in fuzzy dot subalgebras and fuzzy dot ideals of BG-algebras. Also, the notion of fuzzy relations on the family of fuzzy dot subalgebras and fuzzy dot ideals of BG-algebras are introduced with some related properties.

  11. Council celebrates CERN Control Centre

    CERN Multimedia

    2006-01-01

    With the unveiling of its new sign, the CERN Control Centre was officially inaugurated on Thursday 16 March. To celebrate its startup, CERN Council members visited the sleek centre, a futuristic-looking room filled with a multitude of monitoring screens.

  12. Fundamental study of CO2-H2O-mineral interactions for carbon sequestration, with emphasis on the nature of the supercritical fluid-mineral interface.

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R.; Dewers, Thomas A.; Heath, Jason E.; Wang, Yifeng; Matteo, Edward N.; Meserole, Stephen P.; Tallant, David Robert

    2013-09-01

    In the supercritical CO2-water-mineral systems relevant to subsurface CO2 sequestration, interfacial processes at the supercritical fluid-mineral interface will strongly affect core- and reservoir-scale hydrologic properties. Experimental and theoretical studies have shown that water films will form on mineral surfaces in supercritical CO2, but will be thinner than those that form in vadose zone environments at any given matric potential. The theoretical model presented here allows assessment of water saturation as a function of matric potential, a critical step for evaluating relative permeabilities the CO2 sequestration environment. The experimental water adsorption studies, using Quartz Crystal Microbalance and Fourier Transform Infrared Spectroscopy methods, confirm the major conclusions of the adsorption/condensation model. Additional data provided by the FTIR study is that CO2 intercalation into clays, if it occurs, does not involve carbonate or bicarbonate formation, or significant restriction of CO2 mobility. We have shown that the water film that forms in supercritical CO2 is reactive with common rock-forming minerals, including albite, orthoclase, labradorite, and muscovite. The experimental data indicate that reactivity is a function of water film thickness; at an activity of water of 0.9, the greatest extent of reaction in scCO2 occurred in areas (step edges, surface pits) where capillary condensation thickened the water films. This suggests that dissolution/precipitation reactions may occur preferentially in small pores and pore throats, where it may have a disproportionately large effect on rock hydrologic properties. Finally, a theoretical model is presented here that describes the formation and movement of CO2 ganglia in porous media, allowing assessment of the effect of pore size and structural heterogeneity on capillary trapping efficiency. The model results also suggest possible engineering approaches for optimizing trapping capacity and for monitoring ganglion formation in the subsurface.

  13. Synthesis and Structural Characterization of Adduct Cu2(phen)2·3(FCA)·(ClO4)·2H2O

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new dinuclear copper (II) complex containing 3-ferrocenyl-2-crotomic acid salt (FCA) and phen has been synthesized. Its structure was characterized by X-ray crystal analysis. The molecular is a pentametallic compound.

  14. Oxygen-18 incorporation in NICI mass spectrometry: the role of O2, H2O and rhenium oxides in surface-assisted oxidation reactions

    Science.gov (United States)

    Stemmler, Elizabeth A.

    1995-04-01

    Surface-assisted oxidation reactions in the chemical ionization (CI) source have been studied using oxidation yield determinations and oxygen-18 incorporation measurements with 18O2 or H218O added to the negative ion chemical ionization buffer gas (N2 or Ar). Oxidation yield measurements show that O2, but not H2O, affects the oxidation yield. Using 18O2, 18O incorporation was found to be consistently lower in the ionized products of surface-assisted reactions compared with the products of gas-phase ion/molecule reactions. In addition, the degree of 18O incorporation was influenced by ion source temperature, with an increase in ion source temperature reducing the degree of incorporation. Although H2O has a negligible effect upon the efficiency of surface-assisted oxidation reactions, water-derived oxygen is efficiently incorporated by the products of surface-assisted oxidation reactions. In experiments with H218O + O2 mixtures a correlation between the 18O content of the oxidized products and the 18O content of filament-derived ReO4- was observed. This correlation, and the detection of rhenium oxides on ion source surfaces, suggest that filament-derived rhenium oxides may play a role in the activation of ion source surfaces towards the selective surface-catalyzed oxidation of aromatic hydrocarbons.

  15. Magnetic Behavior of Volborthite Cu3 V2 O7 (OH )2.2 H2O Determined by Coupled Trimers Rather than Frustrated Chains

    Science.gov (United States)

    Janson, O.; Furukawa, S.; Momoi, T.; Sindzingre, P.; Richter, J.; Held, K.

    2016-07-01

    Motivated by recent experiments on volborthite single crystals showing a wide 1/3 -magnetization plateau, we perform microscopic modeling by means of density functional theory (DFT) with the single-crystal structural data as a starting point. Using DFT +U , we find four leading magnetic exchanges: antiferromagnetic J and J2, as well as ferromagnetic J' and J1. Simulations of the derived spin Hamiltonian show good agreement with the experimental low-field magnetic susceptibility and high-field magnetization data. The 1/3 -plateau phase pertains to polarized magnetic trimers formed by strong J bonds. An effective J →∞ model shows a tendency towards condensation of magnon bound states preceding the plateau phase.

  16. Structure and properties of binder gels formed in the system Mg(OH)2-SiO2-H2O for immobilisation of Magnox sludge.

    Science.gov (United States)

    Walling, Sam A; Kinoshita, Hajime; Bernal, Susan A; Collier, Nick C; Provis, John L

    2015-05-01

    A cementitious system for the immobilisation of magnesium rich Magnox sludge was produced by blending an Mg(OH)2 slurry with silica fume and an inorganic phosphate dispersant. The Mg(OH)2 was fully consumed after 28 days of curing, producing a disordered magnesium silicate hydrate (M-S-H) with cementitious properties. The structural characterisation of this M-S-H phase by (29)Si and (25)Mg MAS NMR showed clearly that it has strong nanostructural similarities to a disordered form of lizardite, and does not take on the talc-like structure as has been proposed in the past for M-S-H gels. The addition of sodium hexametaphosphate (NaPO3)6 as a dispersant enabled the material to be produced at a much lower water/solids ratio, while still maintaining the fluidity which is essential in practical applications, and producing a solid monolith. Significant retardation of M-S-H formation was observed with larger additions of phosphate, however the use of 1 wt% (NaPO3)6 was beneficial in increasing fluidity without a deleterious effect on M-S-H formation. This work has demonstrated the feasibility of using M-S-H as binder to structurally immobilise Magnox sludge, enabling the conversion of a waste into a cementitious binder with potentially very high waste loadings, and providing the first detailed nanostructural description of the material thus formed. PMID:25833071

  17. Nano structured porous anodized aluminium oxide by using C2H2O4 for electronic applications: Study of the cell potential effects on formation of porous alumina

    International Nuclear Information System (INIS)

    In this research, a nano porous anodized aluminium oxide AAO thin film was successfully grown onto oxide layer on silicon substrate. The anodization of Si/ SiO2/ Al substrate was conducted in a vigorous stirring oxalic acid bath solution. The rate of growth, morphology and also the kinetic study of the AAO thin film were investigated. The resulting array, pores structure and pores density of AAO strongly depends on an applied voltage of the anodizing process. (author)

  18. H2O2, H2O and HDO thermal mapping on Mars using TEXES/IRTF and EXES/SOFIA

    Science.gov (United States)

    Encrenaz, T.; Greathouse, T.; Richter, M.; Lacy, J.; Fouchet, T.; Bézard, B.; Lefèvre, F.; Montmessin, F.; Atreya, S.

    2014-04-01

    Ever since the Viking era, hydrogen peroxide has been suggested as a possible oxidizer of the Mars surface [1]. H2O2 was first detected in the submillimeter range [2], then regularly monitored, simultaneously with HDO, using high-resolution imaging spectroscopy at 8 μm with TEXES at IRTF [3]. Comparison with the Global Climate Models (GCM) shows that the observations favor the simulations taking into account heterogeneous chemistry [4]. New observations have been performed on H2O2 and HDO with TEXES at IRTF in February 2014, and on H2O and HDO with EXES on SOFIA in April 2014. The latter dataset, obtained near summer solstice, will be used to build a map of D/H on Mars.

  19. Dissolution of aragonite-strontianite solid solutions in nonstoichiometric Sr (HCO3)2-Ca (HCO3)2-CO2-H2O solutions

    Science.gov (United States)

    Plummer, L.N.; Busenberg, E.; Glynn, P.D.; Blum, A.E.

    1992-01-01

    Synthetic strontianite-aragonite solid-solution minerals were dissolved in CO2-saturated non-stoichiometric solutions of Sr(HCO3)2 and Ca(HCO3)2 at 25??C. The results show that none of the dissolution reactions reach thermodynamic equilibrium. Congruent dissolution in Ca(HCO3)2 solutions either attains or closely approaches stoichiometric saturation with respect to the dissolving solid. In Sr(HCO3)2 solutions the reactions usually become incongruent, precipitating a Sr-rich phase before reaching stoichiometric saturation. Dissolution of mechanical mixtures of solids approaches stoichiometric saturation with respect to the least stable solid in the mixture. Surface uptake from subsaturated bulk solutions was observed in the initial minutes of dissolution. This surficial phase is 0-10 atomic layers thick in Sr(HCO3)2 solutions and 0-4 layers thick in Ca(HCO3)2 solutions, and subsequently dissolves and/or recrystallizes, usually within 6 min of reaction. The initial transient surface precipitation (recrystallization) process is followed by congruent dissolution of the original solid which proceeds to stoichiometric saturation, or until the precipitation of a more stable Sr-rich solid. The compositions of secondary precipitates do not correspond to thermodynamic equilibrium or stoichiometric saturation states. X-ray photoelectron spectroscopy (XPS) measurements indicate the formation of solid solutions on surfaces of aragonite and strontianite single crystals immersed in Sr(HCO3)2 and Ca(HCO3)2 solutions, respectively. In Sr(HCO3)2 solutions, the XPS signal from the outer ~ 60 A?? on aragonite indicates a composition of 16 mol% SrCO3 after only 2 min of contact, and 14-18 mol% SrCO3 after 3 weeks of contact. The strontianite surface averages approximately 22 mol% CaCO3 after 2 min of contact with Ca(HCO3)2 solution, and is 34-39 mol% CaCO3 after 3 weeks of contact. XPS analysis suggests the surface composition is zoned with somewhat greater enrichment in the outer ~25 A?? (as much as 26 mol% SrCO3 on aragonite and 44 mol% CaCO3 on strontianite). The results indicate rapid formation of a solid-solution surface phase from subsaturated aqueous solutions. The surface phase continually adjusts in composition in response to changes in composition of the bulk fluid as net dissolution proceeds. Dissolution rates of the endmembers are greatly reduced in nonstoichiometric solutions relative to dissolution rates observed in stoichiometric solutions. All solids dissolve more slowly in solutions spiked with the least soluble component ((Sr(HCO3)2)) than in solutions spiked with the more soluble component (Ca(HCO3)2), an effect that becomes increasingly significant as stoichiometric saturation is approached. It is proposed that the formation of a non-stoichiometric surface reactive zone significantly decreases dissolution rates. ?? 1992.

  20. Oxidation of SO2 and formation of water droplets under irradiation of 20MeV protons in N2/H2O/SO2

    DEFF Research Database (Denmark)

    Tomita, Shigeo; Nakai, Yoichi; Funada, Shuhei;

    2015-01-01

    We have performed an experiment on charged droplet formation in a humidified N2 gas with trace SO2 concentration and induced by 20MeV proton irradiation. It is thought that SO2 reacts with the chemical species, such as OH radicals, generated through the reactions triggered by N2+ production. Both...

  1. High-temperature atomic layer epitaxy of TiO2 from TICl4 and H2O2-H2O

    International Nuclear Information System (INIS)

    Epitaxial TiO2 films were grown on off-cut α-Al2O3 (0112) (R-plane sapphire) substrates by gas-phase atomic layer deposition at 550-750 degrees C. X-ray diffraction and reflection high-energy electron diffraction measurements showed that the films had a two-domain (101) textured rutile structure. The domains made a straight angle about the normal to the substrate (0112) plane; those quantitatively superior were 3 degrees inclined with respect to the plane, resulting in the overall orientation relationship (0112) [2110]sapphire//(101)[010],[010](3 degrees)rutile. An account of the two-domain growth was given. The epitaxial quality worsened with the increase in the deposition temperature. (author)

  2. Experimental and kinetic study of the iodine reactivity in low pressure H2/O2/H2O/HI/Ar premixed flames

    International Nuclear Information System (INIS)

    To assess kinetics aspects of iodine chemistry in an environment of a severe accident in a Pressurized Water Reactor (PWR), at the laboratory scale, an experimental reactor named 'flat flame burner' has been implemented. Low pressure flames of H2/O2/Ar premixed gas seeded with known amounts of iodhydric acid and steam were studied. The quantification of chemical species (HI, H2O, OH) in such environment was obtained by specific analytical techniques (Fourier Transform Infrared absorption spectrometry, FTIR and Laser Induced Fluorescence, LIF), the evolution of the temperature was determined by LIF and by thermocouple measurements. Further assays were performed in a flow reactor in which gaseous molecular iodine was injected and transported in a stream or hydrogen flow and a strong temperature gradient, representative of the primary circuit in the case of a severe accident. The resulting gaseous species (I2 and HI) were quantified by ICP-MS and UV-Visible spectrometry. This experimental database has been used as a support to develop a detailed kinetic mechanism for the {I, O, H} system. It is composed of 37 reversible reactions involving 5 iodinated species. The thermo-kinetic parameter database has been actualized by using theoretical chemistry tools and also completed with data found in the literature. Modelling was performed by using the PREMIX code for flame assays, and with the in IRSN's severe accident simulation code ASTEC/SOPHAREOS code for flow reactor assays. The comparison between experiment and modelling shows that this detailed mechanism is able to reproduce the iodine chemistry in conditions representative of a PWR severe accident. (author)

  3. Hydrogen peroxide generated by an atmospheric He-O2-H2O flowing post-discharge: production mechanisms and absolute quantification

    CERN Document Server

    Dufour, Thierry; De Vos, Caroline; Reniers, F

    2016-01-01

    An atmospheric plasma torch has been supplied with a gaseous mixture of helium, water vapour and/or oxygen to study the production of reactive species within its flowing post-discharge, in particular hydrogen peroxide. The mechanisms responsible for the production of H2O2 have been investigated by correlating measurements of mass spectrometry and absorption photospectrometry. An absolute quantification of H2O2 has also been achieved and indicated that for 5 mmol of water vapour injected in the He-H2O discharge, approximately 9.5 mol of H2O2 were produced in post-discharge.

  4. Rhombohedral calcite precipitation from CO2-H2O-Ca(OH)2 slurry under supercritical and gas CO2 media

    CERN Document Server

    Montes-Hernandez, German; Geoffroy, Nicolas; Charlet, Laurent; Pironon, Jacques

    2008-01-01

    The formation of solid calcium carbonate (CaCO3) from aqueous solutions or slurries containing calcium and carbon dioxide (CO2) is a complex process of considerable importance in the ecological, geochemical and biological areas. Moreover, the demand for powdered CaCO3 has increased considerably recently in various fields of industry. The aim of this study was therefore to synthesize fine particles of calcite with controlled morphology by hydrothermal carbonation of calcium hydroxide at high CO2 pressure (initial PCO2=55 bar) and at moderate and high temperature (30 and 90 degrees C). The morphology of precipitated particles was identified by transmission electron microscopy (TEM/EDS) and scanning electron microscopy (SEM/EDS). In addition, an X-ray diffraction analysis was performed to investigate the carbonation efficiency and purity of the solid product. Carbonation of dispersed calcium hydroxide in the presence of supercritical (PT=90 bar, T=90 degrees C) or gaseous (PT=55 bar, T=30 degrees C) CO2 led to t...

  5. Detritiation From Heavy Water by H2-H2O Liquid Phase Catalytic Exchange%氢-水液相催化交换法脱氚

    Institute of Scientific and Technical Information of China (English)

    李俊华

    2001-01-01

    对疏水催化剂的设计与制备方法及氢-水液相交换反应过程进行了讨论,并概要评述了以常温氢-水催化交换法进行重水脱氚的液相催化交换(LPCE)及其联合电解的催化交换(CECE)工艺流程。%The design and preparation of the hydrophobic catalyst used forthe hydrogen-water phase catalytic exchange reaction is discussed in the paper.Two kinds of the processes for the detritiation from the heavy water,liquid phase catalytic exchange(LPCE) and combined electrolysis catalytic exchange(CECE)are reviewed briefly.

  6. Structural determination; vibration study and thermal decomposition of [C5H6N5]2SeO4ṡ2H2O

    Science.gov (United States)

    Ben Hassen, C.; Boujelbene, M.; Mhiri, T.

    2015-01-01

    The present paper reports the chemical synthesis, structure study, thermal analysis, and vibrational properties of new hybrid compound called: bis (adeninium) selenate bihydrates. It is crystallized in the triclinic system with P-1 space group and the following parameters a = 7.804(5) Å; b = 9.686 (5) Å; c = 11.771 (5) Å; α = 84.421(5)°; ß = 77.556(5)°; γ = 81.186 (5)°; Z = 2 and V = 856.7(8) Å3. The structure is built up from tunnels containing all the components of the structure and following to the c axis, linked via three types of hydrogen bonds (Nsbnd H…O, Nsbnd H…N and Osbnd H…O). The thermal decomposition of precursors studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), indicate the existence of two mass loss region correspond to dehydration and degradation of the title compound, respectively. The existence of vibrational modes correspond to the organic and inorganic groups and water molecular are identified by the IR and Raman spectroscopy in the frequency ranges 400-4000 and 300-1600 cm-1, respectively.

  7. Secondary ion emission from CO2-H2O ice irradiated by energetic heavy ions: Part II: Analysis-search for organic ions

    Science.gov (United States)

    Ponciano, C. R.; Farenzena, L. S.; Collado, V. M.; da Silveira, E. F.; Wien, K.

    2005-06-01

    Secondary ion mass spectrometry is used to investigate ion emission from a frozen-gas mixture of CO2 and H2O (T = 80-90 K) bombarded by MeV nitrogen ions and by 252Cf fission fragments. The aim of the experiment is to detect organic molecules, produced in the highly excited material around the nuclear track, which appear as ions in the flux of sputtered particles. Part I of the present work [L.S. Farenzena, V.M. Collado, C.R Ponciano, E.F. da Silveira, K. Wien. Int. J. Mass Spectrom. 243 (2005) 85-93] described the method and presented the time-of-flight mass spectra; a list of the CO2 specific and H2O specific reaction products was provided. In Part II, the peaks of the TOF mass spectra are analyzed. Projectile-ice direct coulomb interaction leads to the production in the track of the H+, C+, O+, O2+, CO+ and CO2+ primarily ions, which react in the highly energized nuclear track plasma mainly with CO2 and H2O or H2CO3. The positive molecular hybrid ions formed are identified as organic species like COH+, COOH+, CHn = 1-3+, Hn = 1,2COOH+ and cluster ions. Similarly, the negative primarily ions O- and OH- formed by electron capture produce negative hybrid ions such as (CO2)nOH-, the four ions (CO4Hm = 0-3)- and the corresponding cluster ions. By far, most of the molecular ions have been formed by one-step reactions; exceptions are eventually the CO4Hm- ions created by a reaction between CO3- and water molecules. An intense mass line corresponding to HCO3+ has been observed, but not the one due to formaldehyde ion. Weak signals of ionic ketene, hydrogen peroxide and carbonic acid were seen.

  8. Ab initio studies of O2-(H2O)n and O3-(H2O)n anionic molecular clusters, n≤12

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Kurtén, T.; Enghoff, Martin Andreas Bødker;

    2011-01-01

    that anionic O2−(H2O)n and O3−(H2O)n clusters are thermally stabilized at typical atmospheric conditions for at least n = 5. The first 4 water molecules are strongly bound to the anion due to delocalization of the excess charge while stabilization of more than 4 H2O is due to normal hydrogen bonding. Although...... clustering up to 12 H2O, we find that the O2 and O3 anions retain at least ca. 80 % of the charge and are located at the surface of the cluster. The O2− and O3− speicies are thus accessible for further reactions. Finally, the thermodynamics of a few relevant cluster reactions are considered....

  9. Molecular Structure and Properties of a Novel Acylhydrazone (C14H14O6N4)·HCON(CH3)2.2H2O

    Institute of Scientific and Technical Information of China (English)

    CHEN Feng-ying; WU Wang-ting; LI Heng-xin; HE Shui-yang; WEN Zhen-yi; LI Jia-xing

    2012-01-01

    Abstract [N-(Propionic acid)] terephthalal acyl dihydrazone(H4L) was synthesized and characterized by element analysis,IR,1H NMR and MS.The theoretical studies on H4L were carried out at HF/6-31+G(d) and B3LYP/6-3 1+G(d) levels.The main decomposition stage of it was studied with IR track.The kinetic parameters[the apparent activation energy(Ea) and pre-exponential constant(A) of the first and second stages of decomposition reaction] were obtained by Kissinger and Ozawa's methods.Furthermore,the antimicrobial activity of H4L against wheat rust was investigated by sporc sprout method.

  10. Spatiotemporal variations in growing season exchanges of CO2, H2O,and sensible heat in agricultural fields of the Southern GreatPlains

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Marc L.; Billesbach, David P.; Berry, Joseph A.; Riley,William J.; Torn, Margaret S.

    2007-06-13

    Climate, vegetation cover, and management create fine-scaleheterogeneity in unirrigated agricultural regions, with important but notwell-quantified consequences for spatial and temporal variations insurface CO2, water, and heat fluxes. We measured eddy covariance fluxesin seven agricultural fields--comprising winter wheat, pasture, andsorghum--in the U.S. Southern Great Plains (SGP) during the 2001-2003growing seasons. Land-cover was the dominant source of variation insurface fluxes, with 50-100 percent differences between fields planted inwinter-spring versus fields planted in summer. Interannual variation wasdriven mainly by precipitation, which varied more than two-fold betweenyears. Peak aboveground biomass and growing-season net ecosystem exchange(NEE) of CO2 increased in rough proportion to precipitation. Based on apartitioning of gross fluxes with a regression model, ecosystemrespiration increased linearly with gross primary production, but with anoffset that increased near the time of seed production. Because theregression model was designed for well-watered periods, it successfullyretrieved NEE and ecosystem parameters during the peak growing season,and identified periods of moisture limitation during the summer. Insummary, the effects of crop type, land management, and water limitationon carbon, water, and energy fluxes were large. Capturing the controllingfactors in landscape scale models will be necessary to estimate theecological feedbacks to climate and other environmental impactsassociated with changing human needs for agricultural production of food,fiber, and energy.

  11. Major, Trace, and Volatile (CO2, H2O, S, F, and Cl) Elements from 1000+ Hawaiian Olivine-hosted Melt Inclusions Reveal the Dynamics of Crustal Recycling

    Science.gov (United States)

    Marske, J. P.; Hauri, E. H.; Trusdell, F.; Garcia, M. O.; Pietruszka, A. J.

    2015-12-01

    Global cycling of volatile elements (H2O, CO2, F, S, Cl) via subduction to deep mantle followed by entrainment and melting within ascending mantle plumes is an enigmatic process that controls key aspects of hot spot volcanism (i.e. melting rate, magma supply, degassing, eruptive style). Variations in radiogenic isotope ratios (e.g.187Os/188Os) at hot spots such as Hawaii reveal magmatic processes within deep-seated mantle plumes (e.g. mantle heterogeneity, lithology, and melt transport). Shield-stage lavas from Hawaii likely originate from a mixed plume source containing peridotite and recycled oceanic crust (pyroxenite) based on variations of radiogenic isotopes. Hawaiian lavas display correlations among isotopes, major and trace elements [1] that might be expected to have an expression in the volatile elements. To investigate this link, we present Os isotopic ratios (n=51), and major, trace, and volatile elements from 1003 olivine-hosted melt inclusions (MI) and their host minerals from tephra from Koolau, Mauna Loa, Hualalai, Kilauea, and Loihi volcanoes. The data show a strong correlation between MI volatile contents and incompatible trace element ratios (La/Yb) with Os isotopes of the same host olivines and reveal large-scale volatile heterogeneity and zonation exists within the Hawaiian plume. 'Loa' chain lavas, which are thought to originate from greater proportions of recycled oceanic crust/pyroxenite, have MIs with lower H2O, S, F, and Cl contents compared to 'Kea' chain lavas that were derived from more peridotite-rich sources. The depletion of volatile elements in the 'Loa' volcano MIs can be explained if they tapped an ancient dehydrated oceanic crust component within the Hawaiian plume. Higher extents of melting beneath 'Loa' volcanoes can also explain these depletions. The presence of dehydrated recycled mafic material in the plume source suggests that subduction effectively devolatilizes part of the oceanic crust. These results are similar to the observed shifts in H2O/Ce ratios near the Easter and Samoan hotspots [2,3]. Thus, it appears that multiple hotspots may record relative H2O depletions and possibly other volatiles. [1] Hauri et al. 1996, Nature 382, 415-419. [2] Dixon et al. 2002, Nature 420:385-89 [3] Workman et al. 2006, EPSL 241:932-51.

  12. Studies in the system MgO-SiO2-CO2-H2O(I): The activity-product constant of chrysotile

    Science.gov (United States)

    Hostetler, P.B.; Christ, C.L.

    1968-01-01

    Chrysotile dissolves congruently in water according to the reaction: Mg3Si2O6(OH)4c + 5H2Ol = 3Mgaq2+ + 6OHaq- + 2H4SiO4aq. Experimental determination of the activity-product constant of chrysotile, Kchr = [Mg2+]3[OH-]6[H4SiO4aq]2, at 90??C, yields the value of Kchr = 10-49.2 ?? 100.5. A synthetic sample and a natural sample from New Idria, California, were used in the determination. Values of Kchr were calculated for temperatures ranging from 0??C to 200??C, using the thermochemical data of King et al. (1967) for chrysotile and antigorite, various solubility data for silica, and ionic partial molal heat capacities estimated by the method of criss and Cobble (1964a). Kchr is 10-54.1 at 0??C, rises to a maximum value of 10-48.5 at approximately 135??C, and is 10-49.1 at 200??C (all values for the three-phase system, chrysotile plus solution plus vapor). The calculated 90??C value is 10-49.1, in excellent agreement with the experimental value; for 25??C, the calculated value is 10-50.8. ?? 1968.

  13. Simulation of Canopy CO2/H2O Fluxes for a Rubber (Hevea Brasiliensis) Plantation in Central Cambodia: The Effect of the Regular Spacing of Planted Trees

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, Tomo' omi; Mudd, Ryan; Miyazawa, Yoshiyuki; Liu, Wen; Giambelluca, Thomas; Kobayashi, N.; Lim, Tiva Khan; Jomura, Mayuko; Matsumoto, Kazuho; Huang, Maoyi; Chen, Qi; Ziegler, Alan; Yin, Song

    2013-09-10

    We developed a soil-vegetation-atmosphere transfer (SVAT) model applicable to simulating CO2 and H2O fluxes from the canopies of rubber plantations, which are characterized by distinct canopy clumping produced by regular spacing of plantation trees. Rubber (Hevea brasiliensis Müll. Arg.) plantations, which are rapidly expanding into both climatically optimal and sub-optimal environments throughout mainland Southeast Asia, potentially change the partitioning of water, energy, and carbon at multiple scales, compared with traditional land covers it is replacing. Describing the biosphere-atmosphere exchange in rubber plantations via SVAT modeling is therefore essential to understanding the impacts on environmental processes. The regular spacing of plantation trees creates a peculiar canopy structure that is not well represented in most SVAT models, which generally assumes a non-uniform spacing of vegetation. Herein we develop a SVAT model applicable to rubber plantation and an evaluation method for its canopy structure, and examine how the peculiar canopy structure of rubber plantations affects canopy CO2 and H2O exchanges. Model results are compared with measurements collected at a field site in central Cambodia. Our findings suggest that it is crucial to account for intensive canopy clumping in order to reproduce observed rubber plantation fluxes. These results suggest a potentially optimal spacing of rubber trees to produce high productivity and water use efficiency.

  14. An Efficient and Chemoselective Deprotection of tert-Butyldimethylsilyl Protected Alcohols Using SnCl2·2H2O as Catalyst

    Institute of Scientific and Technical Information of China (English)

    Jun HUA; Zhi Yong JIANG; Yan Guang WANG

    2004-01-01

    An efficient and selective method for the deprotection of primary alcoholic tert-butylallow primary alcoholic TBS ethers to be desilylated chemoselectively in the presence of phenolic TBS ethers, secondary and tertiary alcolholic TBS ethers, and the extensively used TBDPS-,acetyl-, benzyloxycarbonyl-, p-toluenesulfonyl- and benzyl protective groups.

  15. Shock initiation and detonation study on high concentration H2O2/H2O solutions using in-situ magnetic gauges

    Energy Technology Data Exchange (ETDEWEB)

    Sheffield, Stephen A [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Stahl, David B [Los Alamos National Laboratory; Gibson, L Lee [Los Alamos National Laboratory; Bartram, Brian D [Los Alamos National Laboratory; Engelke, Ray [Los Alamos National Laboratory

    2010-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; homogeneous shock initiation behavior has been observed in the experiments where reaction is observed. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these experiments, we have determined unreacted Hugoniot points, times-to-detonation points that indicate low sensitivity (an input of 13.5 GPa produces detonation in 1 {micro}s compared to 9.5 GPa for neat nitromethane), and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions of over 6.6 km/s.

  16. 2-μm Coherent DIAL for CO2, H2O and Wind Field Profiling in the Lower Atmosphere: Instrumentation and Results

    Directory of Open Access Journals (Sweden)

    Gibert Fabien

    2016-01-01

    Full Text Available We report on 2-μm coherent differential absorption lidar (CDIAL measurements of carbon dioxide (CO2, water vapour (H2O absorption and wind field profiling in the atmospheric boundary layer. The CDIAL uses a Tm:fiber pumped, single longitudinal mode Q-switched seeded Ho:YLF laser and a fibercoupled coherent detection. The laser operates at a pulse repetition frequency of 2 kHz and emits an output energy of 10 mJ with a pulse width of 40 ns (FWHM. Experimental horizontal and vertical range-resolved measurements were made in the atmospheric boundary layer and compared to colocated in-situ sensor data.

  17. Isotopic evidence for the infiltration of mantle and metamorphic CO2-H2O fluids from below in faulted rocks from the San Andreas Fault System

    Energy Technology Data Exchange (ETDEWEB)

    Pili, E.; Kennedy, B.M.; Conrad, M.E.; Gratier, J.-P.

    2010-12-15

    To characterize the origin of the fluids involved in the San Andreas Fault (SAF) system, we carried out an isotope study of exhumed faulted rocks from deformation zones, vein fillings and their hosts and the fluid inclusions associated with these materials. Samples were collected from segments along the SAF system selected to provide a depth profile from upper to lower crust. In all, 75 samples from various structures and lithologies from 13 localities were analyzed for noble gas, carbon, and oxygen isotope compositions. Fluid inclusions exhibit helium isotope ratios ({sup 3}He/{sup 4}He) of 0.1-2.5 times the ratio in air, indicating that past fluids percolating through the SAF system contained mantle helium contributions of at least 35%, similar to what has been measured in present-day ground waters associated with the fault (Kennedy et al., 1997). Calcite is the predominant vein mineral and is a common accessory mineral in deformation zones. A systematic variation of C- and O-isotope compositions of carbonates from veins, deformation zones and their hosts suggests percolation by external fluids of similar compositions and origin with the amount of fluid infiltration increasing from host rocks to vein to deformation zones. The isotopic trend observed for carbonates in veins and deformation zones follows that shown by carbonates in host limestones, marbles, and other host rocks, increasing with increasing contribution of deep metamorphic crustal volatiles. At each crustal level, the composition of the infiltrating fluids is thus buffered by deeper metamorphic sources. A negative correlation between calcite {delta}{sup 13}C and fluid inclusion {sup 3}He/{sup 4}He is consistent with a mantle origin for a fraction of the infiltrating CO{sub 2}. Noble gas and stable isotope systematics show consistent evidence for the involvement of mantle-derived fluids combined with infiltration of deep metamorphic H{sub 2}O and CO{sub 2} in faulting, supporting the involvement of deep fluids percolating through and perhaps weakening the fault zone. There is no clear evidence for a significant contribution from meteoric water, except for overprinting related to late weathering.

  18. Monte Carlo analysis of Pu-H2O and UO2-PuO2-H2O critical assemblies with ENDF/B-IV data

    International Nuclear Information System (INIS)

    A set of critical experiments, comprising thirteen homogeneous Pu-H2O assemblies and twelve UO2-PuO2 lattices, was analyzed with ENDF/B-IV data and the RCPO1 Monte Carlo program, which modeled the experiments explicitly. Some major data sensitivities were also evaluated. For the Pu-H2O assemblies, calculated K/sub eff/ averaged 1.011. The large (2.7%) scatter of K/sub eff/ values for these assemblies was attributed mostly to uncertainties in physical specifications since no clear trends of K/sub eff/ were evident and data sensitivities were insignificant. The UO2-PuO2 lattices showed just one trend of K/sub eff/, which indicated an overprediction of U238 capture consistent with that observed for uranium-H2O experiments. There was however a approx. 1% discrepancy in calculated K/sub eff/ between the two sets of UO2-PuO2 lattices studied

  19. Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process.

    Energy Technology Data Exchange (ETDEWEB)

    1Harry Reid Center for Environmental Studies, Nuclear Science and Technology Division, University of Nevada, Las Vegas, Las Vegas, NV, 89154-4006; Gong, Cynthia-May S; Poineau, Frederic; Lukens, Wayne W; Czerwinski, Kenneth R.

    2008-02-26

    Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the x-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry with the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a the d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but may be augmented by products of reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex (1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent; titration studies indicate a single species from pH 4.5 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The formation of 1 may strongly impact the fate of technetium in the nuclear fuel cycle.

  20. Quantum Dot Sensitized Photoelectrodes

    OpenAIRE

    Thomas Nann; Thomas J. Macdonald

    2011-01-01

    Quantum Dots (QDs) are promising alternatives to organic dyes as sensitisers for photocatalytic electrodes. This review article provides an overview of the current state of the art in this area. More specifically, different types of QDs with a special focus on heavy-metal free QDs and the methods for preparation and adsorption onto metal oxide electrodes (especially titania and zinc oxide) are discussed. Eventually, the key areas of necessary improvements are identified and assessed.

  1. Quantum Dot Sensitized Photoelectrodes

    Directory of Open Access Journals (Sweden)

    Thomas Nann

    2011-11-01

    Full Text Available Quantum Dots (QDs are promising alternatives to organic dyes as sensitisers for photocatalytic electrodes. This review article provides an overview of the current state of the art in this area. More specifically, different types of QDs with a special focus on heavy-metal free QDs and the methods for preparation and adsorption onto metal oxide electrodes (especially titania and zinc oxide are discussed. Eventually, the key areas of necessary improvements are identified and assessed.

  2. Plasmonic fluorescent quantum dots

    OpenAIRE

    Jin, Yongdong; Gao, Xiaohu

    2009-01-01

    Combining multiple discrete components into a single multifunctional nanoparticle could be useful in a variety of applications. Retaining the unique optical and electrical properties of each component after nanoscale integration is, however, a long-standing problem1,2. It is particularly difficult when trying to combine fluorophores such as semiconductor quantum dots with plasmonic materials such as gold, because gold and other metals can quench the fluorescence3,4. So far, the combination of...

  3. Nanocrystal quantum dots

    CERN Document Server

    Klimov, Victor I

    2010-01-01

    ""Soft"" Chemical Synthesis and Manipulation of Semiconductor Nanocrystals, J.A. Hollingsworth and V.I. Klimov Electronic Structure in Semiconductor Nanocrystals: Optical Experiment, D.J. NorrisFine Structure and Polarization Properties of Band-Edge Excitons in Semiconductor Nanocrystals, A.L. EfrosIntraband Spectroscopy and Dynamics of Colloidal Semiconductor Quantum Dots, P. Guyot-Sionnest, M. Shim, and C. WangMultiexciton Phenomena in Semiconductor Nanocrystals, V.I. KlimovOptical Dynamics in Single Semiconductor Quantum Do

  4. Quantum dot nanostructures

    Directory of Open Access Journals (Sweden)

    Mohamed Henini

    2002-06-01

    These sophisticated technologies for the growth of high quality epitaxial layers of compound semiconductor materials on single crystal semiconductor substrates are becoming increasingly important for the development of the semiconductor electronics industry. This article is intended to convey the flavor of the subject by focusing on the technology and applications of self-assembled quantum dots (QDs and to give an introduction to some of the essential characteristics.

  5. The Aube centre; Le Centre de l`Aube

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This educational booklet is devoted to a general presentation of the Aube radioactive wastes storage centre. After a short presentation of the Andra, the French national agency for the management of radioactive wastes, it gives some general information about radioactive wastes (origin, classification), containers (quality assurance and different types), wastes transportation (planning, safety), and about the Aube centre itself: description, treatment and conditioning of drums (compacting and injection), storage facilities, geological situation of the site, and environmental controls. (J.S.)

  6. Contemporary design for 'landmark' centre.

    Science.gov (United States)

    2009-08-01

    As one of the UK's largest builders of healthcare facilities, construction company Morgan Ashurst is accustomed to delivering complex, challenging hospital projects. The construction of a new oncology centre at Musgrove Park Hospital, Taunton for Taunton and Somerset NHS Foundation Trust-- said to be the first new stand-alone radiotherapy centre to be built in the UK for almost 20 years--was no exception. Health Estate Journal reports. PMID:19711668

  7. The centre of the action

    CERN Document Server

    2008-01-01

    The CERN Control Centre (CCC) has all the ingredients of an action movie control room: hundreds of screens, technicians buzzing in and out, huge floor-to-ceiling windows revealing the looming vista of a mountain range, flashing lights, microphones… This is the place where not just the LHC, but the whole of CERN’s accelerator complex and technical support is based - truly the centre of the action at CERN.

  8. Inter-dot coupling effects on transport through correlated parallel coupled quantum dots

    Indian Academy of Sciences (India)

    Shyam Chand; G Rajput; K C Sharma; P K Ahluwalia

    2009-05-01

    Transport through symmetric parallel coupled quantum dot system has been studied, using non-equilibrium Green function formalism. The inter-dot tunnelling with on-dot and inter-dot Coulomb repulsion is included. The transmission coefficient and Landaur–Buttiker like current formula are shown in terms of internal states of quantum dots. The effect of inter-dot tunnelling on transport properties has been explored. Results, in intermediate inter-dot coupling regime show signatures of merger of two dots to form a single composite dot and in strong coupling regime the behaviour of the system resembles the two decoupled dots.

  9. Training centres - organization and management

    International Nuclear Information System (INIS)

    In the lecture 'Training centres - organization and management' some principles and requirements which influence the organization, management and activity pattern of nuclear training centres, are briefly introduced. It is demonstrated, step by step, how these general principles are implemented in the development of the Czechoslovak nuclear power programme, it means, how the training of the NPP personnel proceeds in Czechoslovak nuclear training centres. General principles which are selected: a connection between the capacity of the training centre and the scope and needs of the nuclear power programme, a position of the training center within the institutional set-up, a structure and organization of the training system which complies with the system of NPP construction, reflect the pattern and the activity of the nuclear training centre and nuclear power technical level, a research group of workers in the nuclear training centre, main tasks and technical facilities, management of the training process and a transfer of knowledge and research results into the training process. The lecture is supplemented by pictures and slides. (orig.)

  10. A dimer of bis(N-heterocyclic carbenerhodium(I centres spanned by a dibenzo-18-crown-6 bridge from synchrotron radiation

    Directory of Open Access Journals (Sweden)

    Stephen B. Colbran

    2013-01-01

    Full Text Available The compound (μ-3,3′,3′′,3′′′-{[2,5,8,15,18,21-hexaoxatricyclo[20.4.0.09,14]hexacosa-1(22,9,11,13,23,25-hexaene-11,12,24,25-tetrayl]tetrakis(methylene}tetrakis(1-methyl-1H-imidazol-2-ylbis[(η4-cycloocta-1,4-dienerhodium(I] bis(hexafluoridophosphate acetonitrile sesquisolvate dihydrate, [Rh2(C8H122(C40H42N8O6](PF62·1.5CH3CN·2H2O, crystallized from acetonitrile under an atmosphere of diethyl ether. In the crystal structure, the complex cation exhibits two square-planar RhI centres, each bound by a cyclooctadiene (COD ligand and by two adjacent imidazolylidene N-heterocyclic carbene (NHC donors from the same phenoxy ring of the {[dibenzo-18-crown-6-11,12,24,25-tetrayl]tetrakis(methylene}tetrakis(1-methyl-1H-imidazol-2-yl (L ligand. The dibenzo-crown ether bridge of L spans the Rh centres and forms hydrogen bonds with water molecules. One water molecule with half occupancy bridges adjacent macrocycles in the lattice. Another water with full occupancy forms weak hydrogen bonds to the crown ether O atoms and is, in turn, part hydrogen bonded by a lattice water with half occupancy. The latter water is within hydrogen-bonding distance of a fourth water also with partial occupancy. The result of these interactions is the formation of a layer in the ab plane. Two PF6− ions, one of which is twofold disordered, and one ordered and one twofold disordered (with 0.5 occupancy lattice acetonitrile molecules complete the crystal structure.

  11. Perceptual strategies of pigeons to detect a rotational centre--a hint for star compass learning?

    Science.gov (United States)

    Alert, Bianca; Michalik, Andreas; Helduser, Sascha; Mouritsen, Henrik; Güntürkün, Onur

    2015-01-01

    Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy.

  12. Perceptual strategies of pigeons to detect a rotational centre--a hint for star compass learning?

    Directory of Open Access Journals (Sweden)

    Bianca Alert

    Full Text Available Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy.

  13. The ideal Atomic Centre; Le Centre Atomique ideal

    Energy Technology Data Exchange (ETDEWEB)

    Mas, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The author presents considerations which should prove to be of interest to all those who have to design, to construct and to operate a nuclear research centre. A large number of the ideas presented can also be applied to non-nuclear scientific research centres. In his report the author reviews: various problems with which the constructor is faced: ground-plan, infrastructure, buildings and the large units of scientific equipment in the centre, and those problems facing the director: maintenance, production, supplies, security. The author stresses the relationship which ought to exist between the research workers and the management. With this aim in view he proposes the creation of National School for Administration in Research which would train administrative executives for public or private organisations; they would be specialised in the fields of fundamental or applied research. (author) [French] L'auteur propose une base de reflexions a tous ceux qui doivent concevoir, realiser et faire vivre un Centre d'Etudes Nucleaires. Un grand nombre des idees exprimees peut d'ailleurs s'appliquer a un Centre d'Etudes Scientifiques non nucleaires. Dans son ouvrage, l'auteur passe en revue les differents problemes qui se posent au constructeur: plan, masse, infrastructure, batiments et grands appareils du Centre, et ceux qu'a a resoudre le directeur: entretien, fabrication, approvisionnements, securite. L'auteur insiste sur l'aspect des rapports qui doivent exister entre les chercheurs et ceux qui les administrent. Il propose a cette fin la creation d'une Ecole Nationale d'Administration de la Recherche qui formerait des cadres administratifs pour les organismes publics ou prives, specialises dans la Recherche fondamentale ou appliquee. (auteur)

  14. The Galactic centre pulsar population

    CERN Document Server

    Chennamangalam, Jayanth

    2013-01-01

    The recent discovery of a magnetar in the Galactic centre region has allowed Spitler et al. to characterize the interstellar scattering in that direction. They find that the temporal broadening of the pulse profile of the magnetar is substantially less than that predicted by models of the electron density of that region. This raises the question of what the plausible limits for the number of potentially observable pulsars - i.e., the number of pulsars beaming towards the Earth - in the Galactic centre region are. In this paper, using realistic assumptions, we show that the potentially observable population of pulsars in the inner parsec has a conservative upper limit of $\\sim$950, and that it is premature to conclude that the number of pulsars in this region is small. We also show that the observational results so far are consistent with this number and make predictions for future radio pulsar surveys of the Galactic centre.

  15. Construction of the Wigner Data Centre

    CERN Multimedia

    2013-01-01

    A remote extension of the CERN data centre has recently been inaugurated. Hosted at the Wigner Research Centre for Physics in Hungary, it provides extra computing power required to cover CERN’s needs. This video presents the construction of the Wigner Data Centre from initial demolishing work through to its completion and details the major technical characteristics of the Data Centre.

  16. Complex dynamics in planar two-electron quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Schroeter, Sebastian Josef Arthur

    2013-06-25

    Quantum dots play an important role in a wide range of recent experimental and technological developments. In particular they are promising candidates for realisations of quantum bits and further applications in quantum information theory. The harmonically confined Hooke's atom model is experimentally verified and separates in centre-of-mass and relative coordinates. Findings that are contradictory to this separability call for an extension of the model, in particular changing the confinement potential. In order to study effects of an anharmonic confinement potential on spectral properties of planar two-electron quantum dots a sophisticated numerical approach is developed. Comparison between the Helium atom, Hooke's atom and an anharmonic potential model are undertaken in order to improve the description of quantum dots. Classical and quantum features of complexity and chaos are investigated and used to characterise the dynamics of the system to be mixed regular-chaotic. Influence of decoherence can be described by quantum fidelity, which measures the effect of a perturbation on the time evolution. The quantum fidelity of eigenstates of the system depends strongly on the properties of the perturbation. Several methods for solving the time-dependent Schrödinger equation are implemented and a high level of accuracy for long time evolutions is achieved. The concept of offset entanglement, the entanglement of harmonic models in the noninteracting limit, is introduced. This concept explains different questions raised in the literature for harmonic quantum dot models, recently. It shows that only in the groundstate the electrons are not entangled in the fermionic sense. The applicability, validity, and origin of Hund's first rule in general quantum dot models is further addressed. In fact Hund's first rule is only applicable, and in this case also valid, for one pair of singlet and triplet states in Hooke's atom. For more realistic models of two

  17. Complex dynamics in planar two-electron quantum dots

    International Nuclear Information System (INIS)

    Quantum dots play an important role in a wide range of recent experimental and technological developments. In particular they are promising candidates for realisations of quantum bits and further applications in quantum information theory. The harmonically confined Hooke's atom model is experimentally verified and separates in centre-of-mass and relative coordinates. Findings that are contradictory to this separability call for an extension of the model, in particular changing the confinement potential. In order to study effects of an anharmonic confinement potential on spectral properties of planar two-electron quantum dots a sophisticated numerical approach is developed. Comparison between the Helium atom, Hooke's atom and an anharmonic potential model are undertaken in order to improve the description of quantum dots. Classical and quantum features of complexity and chaos are investigated and used to characterise the dynamics of the system to be mixed regular-chaotic. Influence of decoherence can be described by quantum fidelity, which measures the effect of a perturbation on the time evolution. The quantum fidelity of eigenstates of the system depends strongly on the properties of the perturbation. Several methods for solving the time-dependent Schrödinger equation are implemented and a high level of accuracy for long time evolutions is achieved. The concept of offset entanglement, the entanglement of harmonic models in the noninteracting limit, is introduced. This concept explains different questions raised in the literature for harmonic quantum dot models, recently. It shows that only in the groundstate the electrons are not entangled in the fermionic sense. The applicability, validity, and origin of Hund's first rule in general quantum dot models is further addressed. In fact Hund's first rule is only applicable, and in this case also valid, for one pair of singlet and triplet states in Hooke's atom. For more realistic models of two-electron quantum dots an

  18. LDE centres: sprint or marathon?

    NARCIS (Netherlands)

    Bonger, S.; Van Rein, E.

    2015-01-01

    The aim of the Strategic Leiden-Delft-Erasmus Alliance, established by the three universities in 2012, was to improve research and education and competitiveness. Projects are intended to develop from the ground up, which led to the establishment of eight joint centres in 2013. A quick look around re

  19. Fossil Dot Com

    DEFF Research Database (Denmark)

    2011-01-01

    Since the start of the industrial revolution in 1800, with breakthrough innovations in iron production, textile industry and the steam engine, society has sustained incredible growth and transformation. During the 200 years, worldwide individual productivity has grown more than 32 times...... technological examples from his background as director of the innovation centre at DONG Energy, Charles Nielsen will discuss the impact of upcoming changes to the backbone of industry: the energy supply. DONG Energy has an ambitious strategy of changing the energy supply from 15% to 85% renewable energy before...

  20. Quantum dots: Rethinking the electronics

    Science.gov (United States)

    Bishnoi, Dimple

    2016-05-01

    In this paper, we demonstrate theoretically that the Quantum dots are quite interesting for the electronics industry. Semiconductor quantum dots (QDs) are nanometer-scale crystals, which have unique photo physical, quantum electrical properties, size-dependent optical properties, There small size means that electrons do not have to travel as far as with larger particles, thus electronic devices can operate faster. Cheaper than modern commercial solar cells while making use of a wider variety of photon energies, including "waste heat" from the sun's energy. Quantum dots can be used in tandem cells, which are multi junction photovoltaic cells or in the intermediate band setup. PbSe (lead selenide) is commonly used in quantum dot solar cells.

  1. Electroluminescent hybrid organic/inorganic quantum dot devices

    International Nuclear Information System (INIS)

    The synthesis of PbS crystallites in aqueous solution in the presence of ethylenediaminetetraacetic acid (EDTA) has been investigated. Nanocrystalline material exhibiting charge confinement effects have been observed. The factors affecting crystallite growth, and hence the optical properties of the ultimately synthesised sample have been studied. A simple analytical model of the linear optical properties of quantum dots of finite size distribution has been developed. The model has been used in conjunction with the effective mass approximation (EMA) in order to model the optical properties of the synthesised PbS with a great deal of success. The EMA is found to limit the applicability of the optical model to samples of quantum dots consisting of larger crystallites as one would expect. Size-quantised CdSe particles have also been synthesised in aqueous solution. The same optical model successfully models the absorption spectra of these quantum dots, subject to the constraints of the EMA. Excessive scattering of light in solutions containing flocculated and/or bulk material is also found to limit the applicability of the model. The incorporation of colloidally suspended quantum dots into optoelectronic device structures has been considered. Energy level offsets between the quantum dots and host matrices have been studied and have been found to be unfavourable to the injection of electronic charge from the matrix into the dots. Alternative electroluminescent device structures in which the quantum dots are incorporated into electroluminescent host matrices which optically pump the quantum dots have therefore been proposed. Such devices have proved difficult to fabricate, eventual luminescence from quantum dot surface states having been obtained, but luminescence from the quantum dot effective bandgap not having been obtained. The scope of the project has extended to the investigation of charge injection into the quantum dot matrix materials themselves from the device

  2. Photonics of shungite quantum dots

    OpenAIRE

    Razbirin, Boris S.; Rozhkova, Natalia N.; Sheka, Elena F.

    2014-01-01

    Shungite quantum dots are associated with nanosize fragments of reduced graphene oxide similarly to synthetic graphene quantum dots thus forming a common class of GQDs. Colloidal dispersions of powdered shungite in water, carbon tetrachloride, and toluene form the ground for the GQD photonic peculiarities manifestation. Morphological study shows a steady trend of GQDs to form fractals and a drastic change in the colloids fractal structure caused by solvent was reliably established. Spectral s...

  3. Spin pumping through quantum dots

    OpenAIRE

    Rojek, Stephan; Governale, Michele; König, Jürgen

    2013-01-01

    We propose schemes for generating spin currents into a semiconductor by adiabatic or non-adiabatic pumping of electrons through interacting quantum dots. The appeal of such schemes lies in the possibility to tune the pumping characteristics via gate voltages that control the properties of the quantum dot. The calculations are based on a systematic perturbation expansion in the tunnel-coupling strength and the pumping frequency, expressed within a diagrammatic real-time technique. Special focu...

  4. [CUⅡ(BTAH)2(NCS)2]·2H2O(BTAH=苯并三唑)的合成、晶体结构及其光学性能%Synthesis, Crystal Structure and Optical Properties of Copper Coordination Polymer of Benzotriazole and Thiocyanate, [CuⅡ(BTAH)2(NCS)2]·2H2O (BTAH = Benzotriazole)

    Institute of Scientific and Technical Information of China (English)

    李秀艳; 郭洪猷; 傅吉全

    2006-01-01

    通过水热法,合成了[CuⅡ(BTAH)2(NCS)2]·2H2O晶体.对其进行了元素分析、红外光谱以及热重分析,并通过单晶X射线衍射确定了其晶体结构.该晶体属于三斜晶系,空间群为Pi,晶胞参数为a=0.64174(6)nm,b=0.83749(8)nm,c=0.92831(5)nm,a=71.982(5)°,β=72.522(6)°,γ=77.068(4)°.通过UV-VIS-NIR反射光谱研究了其光学性质,能隙值为2.5eV,吸光系数(ε)为0.0294μm-1.

  5. Synthesis and Crystal Structure of [Cu2(bpa)2(phen)2(H2O)]2·H2O%[Cu2(bpa)2(phen)2(H2O)]2·H2O的合成和晶体结构

    Institute of Scientific and Technical Information of China (English)

    刘琼馨; 孟凡瑾; 孙选举; 朱海亮

    2003-01-01

    利用线形的芳香二羧酸与邻菲啉铜盐在水热的条件下合成一种新型的分子块化合物,这种分子块通过位于钝角位置的邻菲啉配体的芳香π-π识别作用自组装成第一例由菱形分子块的自组装形成二维多聚轮烷,这种二维的层状结构通过邻菲啉配体的芳香π-π堆积作用形成具有独特拓扑结构的三维网络结构.

  6. Thermodynamics Analysis of Cesium Adsorption on Na2Ti2O3SiO4 · 2H2O%钛硅酸钠( Na2Ti2O3SiO4·2H2O)对Cs的吸附热力学分析

    Institute of Scientific and Technical Information of China (English)

    王保柱; 张东; 石正坤; 吴涛

    2012-01-01

    钛硅酸钠(Crystalline Sillicotitanate,CST)对铯(Cs)的吸附热力学分析是研究钛硅酸钠吸附铯机理的重要途径之一.本工作通过研究不同温度下CST与不同浓度CsNO3溶液反应,测定反应前后Cs+的浓度变化,得到了一系列参数.结果显示,不同的反应温度对应不同的饱和吸附量,当温度为298.15、313.15和328.15 K时,饱和吸附量分别为212.8、217.4和232.6 mg/g.分别用Langmuir方程和Freundlich方程对实验数据进行拟合,结果表明,此吸附过程更符合Langmuir等温吸附.在不考虑温度对吸附焓和吸附熵影响的前提下,计算得到吸附焓△H=21.28 kJ/mol,△S=89.18 J/K/mol以及△G<0.以上结果表明,CST对Cs的吸附过程是一个自发进行、既有物理吸附又有化学吸附的吸热反应.%Thermodynamical analysis of cesium adsorption on CST is considered to be one of the important approaches in studying the adsorption mechanism of cesium on CST. A series of parameters were obtained by measuring the change of the Cs+ ion concentration before and after the sorption. The CST sorption experiments were conducted with the CsNO3 solution at different concentrations and temperatures. The saturation adsorption was found to be 212.8, 217.4 and 232.6 mg/g at 298. 15, 313. 15 and 328. 15 K, respectively. The experimental data were fitted with the Langmuir model or the Freundlich model. The results showed that the Langmuir isotherm better fits this adsorption process. With the assumption that the adsorption enthalpy and adsorption entropy are independent of the temperature, theadsorption enthalpy and entropy were calculated to be 21. 28 kJ/mol and 89. 18 J ? K-1 ? Mol-1 , respectively, with a negative adsorption free energy. The results indicated that the adsorption of cesium on CST is a spontaneous and endothermic process, with both physical and chemical adsorptions involved.

  7. The INTEGRAL Science Data Centre

    OpenAIRE

    Beckmann, V.

    2002-01-01

    The INTEGRAL Science Data Centre (ISDC) processes, archives and distributes data from the INTEGRAL mission. At the ISDC incoming data from the satellite are processed and searched for transient sources and Gamma-Ray bursts. The data are archived and distributed to the guest observers. As soon as the data are public, any astronomer can access the data via the internet. ISDC also provides the tools which are necessary for the data analysis and offers user support concerning questions related to...

  8. Radwaste Treatment Centre Jaslovske Bohunice

    International Nuclear Information System (INIS)

    In this leaflet the Bohunice Radwaste Treatment Centre (BSC RAO) is presented. BSC RAO is designed to process and treat liquid and solid radwaste, arising from the NPP A-1 decommissioning, from NPPs V-1, V-2, and Mochovce operations, as well as institutional radwaste of diverse institutional (hospitals, research institutes) in the Slovak Republic. Transport, sorting, incineration, compacting, concentration and cementation of radwaste as well as monitoring of emission are described

  9. Fuzzy dot ideals and fuzzy dot H-ideals of BCH-algebras

    Institute of Scientific and Technical Information of China (English)

    PENG Jia-yin

    2008-01-01

    The notions of fuzzy dot ideals and fuzzy dot H-ideals in BCH-algebras are intro duced,several appropriate examples are provided,and their some properties are investigated.The relations among fuzzy ideal,fuzzy H-ideal,fuzzy dot ideal and fuzzy dot H-ideals in BCH algebras are discussed,several equivalent depictions of fuzzy dot ideal are obtained. How to deal with the homomorphic image and inverse image of fuzzy dot ideals (fuzzy dot H-ideals) are studied. The relations between a fuzzy dot ideal (fuzzy dot H-ideal) in BCH-algebras and a fuzzy dot ideal (fuzzy dot H-ideal) in the product algebra of BCH-algebras are given.

  10. The Notting Dale Urban Studies Centre

    Science.gov (United States)

    Webb, Chris; Lynas, Sue

    1976-01-01

    Founded in 1974, the Centre is one of the most intensively used resource centres in the United Kingdom. Adults and students from elementary to college level use its facilities to learn about the urban environment. (BD)

  11. Single to quadruple quantum dots with tunable tunnel couplings

    Energy Technology Data Exchange (ETDEWEB)

    Takakura, T.; Noiri, A.; Obata, T.; Yoneda, J.; Yoshida, K. [Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Otsuka, T.; Tarucha, S. [Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); RIKEN, Center for Emergent Matter Science, 3-1 Wako-shi, Saitama 351-0198 (Japan)

    2014-03-17

    We prepare a gate-defined quadruple quantum dot to study the gate-tunability of single to quadruple quantum dots with finite inter-dot tunnel couplings. The measured charging energies of various double dots suggest that the dot size is governed by the gate geometry. For the triple and quadruple dots, we study the gate-tunable inter-dot tunnel couplings. For the triple dot, we find that the effective tunnel coupling between side dots significantly depends on the alignment of the center dot potential. These results imply that the present quadruple dot has a gate performance relevant for implementing spin-based four-qubits with controllable exchange couplings.

  12. Near-infrared quantum dots for HER2 localization and imaging of cancer cells

    OpenAIRE

    Rizvi SB; Rouhi S; Taniguchi S; Yang SY; Green M; Keshtgar M; Seifalian AM

    2014-01-01

    Sarwat B Rizvi,1 Sepideh Rouhi,1 Shohei Taniguchi,2 Shi Yu Yang,1 Mark Green,2 Mo Keshtgar,1,3 Alexander M Seifalian1,3 1UCL Centre for Nanotechnology and Regenerative Medicine, University College London, 2Department of Physics, King's College London, 3Royal Free London NHS Foundation Trust Hospital, London, UK Background: Quantum dots are fluorescent nanoparticles with unique photophysical properties that allow them to be used as diagnostic, therapeutic, and theranostic agents, part...

  13. InAs/GaAs submonolayer quantum dot superluminescent diode emitting around 970 nm

    Institute of Scientific and Technical Information of China (English)

    Li Xin-Kun; Liang De-Chun; Jin Peng; An Qi; Wei Heng; Wu Jian; Wang Zhan-Guo

    2012-01-01

    According to the InAs/GaAs submonolayer quantum dot active region,we demonstrate a bent-waveguide superlnminescent diode emitting at a wavelength of around 970 nm.At a pulsed injection current of 0.5 A,the device exhibits an output power of 24 mW and an emission spectrum centred at 971 nm with a full width at half maximum of 16 nm.

  14. Engineering colloidal quantum dot solids within and beyond the mobility-invariant regime

    KAUST Repository

    Zhitomirsky, David

    2014-05-06

    © 2014 Macmillan Publishers Limited. Colloidal quantum dots are attractive materials for efficient, low-cost and facile implementation of solution-processed optoelectronic devices. Despite impressive mobilities (1-30 cm2V-1 s-1) reported for new classes of quantum dot solids, it is-surprisingly-the much lower-mobility (10-3-10-2 cm2V-1 s-1) solids that have produced the best photovoltaic performance. Here we show that it is not mobility, but instead the average spacing among recombination centres that governs the diffusion length of charges in today\\'s quantum dot solids. In this regime, colloidal quantum dot films do not benefit from further improvements in charge carrier mobility. We develop a device model that accurately predicts the thickness dependence and diffusion length dependence of devices. Direct diffusion length measurements suggest the solid-state ligand exchange procedure as a potential origin of the detrimental recombination centres. We then present a novel avenue for in-solution passivation with tightly bound chlorothiols that retain passivation from solution to film, achieving an 8.5% power conversion efficiency.

  15. Scheduling participants of Assessment Centres

    DEFF Research Database (Denmark)

    Lysgaard, Jens; Løber, Janni

      Assessment Centres are used as a tool for psychologists and coaches to observe a number of dimensions in a person's behaviour and test his/her potential within a number of chosen focus areas. This is done in an intense course, with a number of different exercises which expose each participant......'s ability level in the chosen focus areas. The participants are observed by assessors with the purpose of gathering material for reaching a conclusion on each participant's personal profile. We consider the particular case that arises at the company Human Equity (www.humanequity.dk), where Assessment...

  16. Optical Fiber Sensing Using Quantum Dots

    OpenAIRE

    Faramarz Farahi; José Luís Santos; Tito Trindade; Manuel António Martins; Pedro Jorge

    2007-01-01

    Recent advances in the application of semiconductor nanocrystals, or quantum dots, as biochemical sensors are reviewed. Quantum dots have unique optical properties that make them promising alternatives to traditional dyes in many luminescence based bioanalytical techniques. An overview of the more relevant progresses in the application of quantum dots as biochemical probes is addressed. Special focus will be given to configurations where the sensing dots are incorporated in sol...

  17. A colloidal quantum dot spectrometer

    Science.gov (United States)

    Bao, Jie; Bawendi, Moungi G.

    2015-07-01

    Spectroscopy is carried out in almost every field of science, whenever light interacts with matter. Although sophisticated instruments with impressive performance characteristics are available, much effort continues to be invested in the development of miniaturized, cheap and easy-to-use systems. Current microspectrometer designs mostly use interference filters and interferometric optics that limit their photon efficiency, resolution and spectral range. Here we show that many of these limitations can be overcome by replacing interferometric optics with a two-dimensional absorptive filter array composed of colloidal quantum dots. Instead of measuring different bands of a spectrum individually after introducing temporal or spatial separations with gratings or interference-based narrowband filters, a colloidal quantum dot spectrometer measures a light spectrum based on the wavelength multiplexing principle: multiple spectral bands are encoded and detected simultaneously with one filter and one detector, respectively, with the array format allowing the process to be efficiently repeated many times using different filters with different encoding so that sufficient information is obtained to enable computational reconstruction of the target spectrum. We illustrate the performance of such a quantum dot microspectrometer, made from 195 different types of quantum dots with absorption features that cover a spectral range of 300 nanometres, by measuring shifts in spectral peak positions as small as one nanometre. Given this performance, demonstrable avenues for further improvement, the ease with which quantum dots can be processed and integrated, and their numerous finely tuneable bandgaps that cover a broad spectral range, we expect that quantum dot microspectrometers will be useful in applications where minimizing size, weight, cost and complexity of the spectrometer are critical.

  18. Core Competencies Of A Call Centre AgentCore Competencies Of A Call Centre Agent

    OpenAIRE

    Christine White; Vera Roos

    2005-01-01

    Call centre agents are becoming increasingly important in the call centre context. They act as a contact point between the customer and the company. Call centre agents should have certain competencies to perform their duties sufficiently. Identifying competencies, required to be effective agents, will ease the task of training and recruitment. Due to the interrelatedness of the call centre agent, the management of a call centre and customers, all relevant role players’ perceptions were taken ...

  19. Quantum-dot emitters in photonic nanostructures

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Stobbe, Søren; Lodahl, Peter

    2010-01-01

    The spontaneous emission from self-assembled semiconductor quantum dots is strongly influenced by the environment in which they are placed. This can be used to determine fundamental optical properties of the quantum dots as well as to manipulate and control the quantum-dot emission itself....

  20. Beer's law in semiconductor quantum dots

    CERN Document Server

    Adamashvili, G T

    2010-01-01

    The propagation of a coherent optical linear wave in an ensemble of semiconductor quantum dots is considered. It is shown that a distribution of transition dipole moments of the quantum dots changes significantly the polarization and Beer's absorption length of the ensemble of quantum dots. Explicit analytical expressions for these quantities are presented.

  1. Perceptual centres in speech - an acoustic analysis

    Science.gov (United States)

    Scott, Sophie Kerttu

    Perceptual centres, or P-centres, represent the perceptual moments of occurrence of acoustic signals - the 'beat' of a sound. P-centres underlie the perception and production of rhythm in perceptually regular speech sequences. P-centres have been modelled both in speech and non speech (music) domains. The three aims of this thesis were toatest out current P-centre models to determine which best accounted for the experimental data bto identify a candidate parameter to map P-centres onto (a local approach) as opposed to the previous global models which rely upon the whole signal to determine the P-centre the final aim was to develop a model of P-centre location which could be applied to speech and non speech signals. The first aim was investigated by a series of experiments in which a) speech from different speakers was investigated to determine whether different models could account for variation between speakers b) whether rendering the amplitude time plot of a speech signal affects the P-centre of the signal c) whether increasing the amplitude at the offset of a speech signal alters P-centres in the production and perception of speech. The second aim was carried out by a) manipulating the rise time of different speech signals to determine whether the P-centre was affected, and whether the type of speech sound ramped affected the P-centre shift b) manipulating the rise time and decay time of a synthetic vowel to determine whether the onset alteration was had more affect on P-centre than the offset manipulation c) and whether the duration of a vowel affected the P-centre, if other attributes (amplitude, spectral contents) were held constant. The third aim - modelling P-centres - was based on these results. The Frequency dependent Amplitude Increase Model of P-centre location (FAIM) was developed using a modelling protocol, the APU GammaTone Filterbank and the speech from different speakers. The P-centres of the stimuli corpus were highly predicted by attributes of

  2. The new AMS control centre

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    Construction work for the future AMS control room began in November 2010 and should be finished this June. The new building, which will have been completed in record time thanks to the professionalism of the project team, will soon be ready to receive the initial data from the AMS experiment.     Luigi Scibile and Michael Poehler, from the GS department, at the AMS control centre construction site.   The Alpha Magnetic Spectrometer (AMS) is due to wing its way towards the International Space Station (ISS) on board the shuttle Discovery in April. Mainly intended for research on antimatter and dark matter, the data collected by AMS will be sent to Houston in the United States and then directly to CERN’s new Building 946. Construction work for the AMS control centre building on the Route Gentner at CERN’s Prévessin site started in November 2010 and must be completed in time to receive the first data from the spectrometer in June. “It normall...

  3. Spin storage in quantum dot ensembles and single quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, Dominik

    2009-10-15

    This thesis deals with the investigation of spin relaxation of electrons and holes in small ensembles of self-assembled quantum dots using optical techniques. Furthermore, a method to detect the spin orientation in a single quantum dot was developed in the framework of this thesis. A spin storage device was used to optically generate oriented electron spins in small frequency selected quantum dot ensembles using circularly polarized optical excitation. The spin orientation can be determined by the polarization of the time delayed electroluminescence signal generated by the device after a continuously variable storage time. The degree of spin polarized initialization was found to be limited to 0.6 at high magnetic fields, where anisotropic effects are compensated. The spin relaxation was directly measured as a function of magnetic field, lattice temperature and s-shell transition energy of the quantum dot by varying the spin storage time up to 30 ms. Very long spin lifetimes are obtained with a lower limit of T{sub 1}=20 ms at B=4 T and T=1 K. A strong magnetic field dependence T{sub 1}{proportional_to}B{sup -5} has been observed for low temperatures of T=1 K which weakens as the temperature is increased. In addition, the temperature dependence has been determined with T{sub 1}{proportional_to}T{sup -1}. The characteristic dependencies on magnetic field and temperature lead to the identification of the spin relaxation mechanism, which is governed by spin-orbit coupling and mediated by single phonon scattering. This finding is qualitatively supported by the energy dependent measurements. The investigations were extended to a modified device design that enabled studying the spin relaxation dynamics of heavy holes in self-assembled quantum dots. The measurements show a polarization memory effect for holes with up to 0.1 degree of polarization. Furthermore, investigations of the time dynamics of the hole spin relaxation reveal surprisingly long lifetimes T{sub 1}{sup h

  4. Spin storage in quantum dot ensembles and single quantum dots

    International Nuclear Information System (INIS)

    This thesis deals with the investigation of spin relaxation of electrons and holes in small ensembles of self-assembled quantum dots using optical techniques. Furthermore, a method to detect the spin orientation in a single quantum dot was developed in the framework of this thesis. A spin storage device was used to optically generate oriented electron spins in small frequency selected quantum dot ensembles using circularly polarized optical excitation. The spin orientation can be determined by the polarization of the time delayed electroluminescence signal generated by the device after a continuously variable storage time. The degree of spin polarized initialization was found to be limited to 0.6 at high magnetic fields, where anisotropic effects are compensated. The spin relaxation was directly measured as a function of magnetic field, lattice temperature and s-shell transition energy of the quantum dot by varying the spin storage time up to 30 ms. Very long spin lifetimes are obtained with a lower limit of T1=20 ms at B=4 T and T=1 K. A strong magnetic field dependence T1∝B-5 has been observed for low temperatures of T=1 K which weakens as the temperature is increased. In addition, the temperature dependence has been determined with T1∝T-1. The characteristic dependencies on magnetic field and temperature lead to the identification of the spin relaxation mechanism, which is governed by spin-orbit coupling and mediated by single phonon scattering. This finding is qualitatively supported by the energy dependent measurements. The investigations were extended to a modified device design that enabled studying the spin relaxation dynamics of heavy holes in self-assembled quantum dots. The measurements show a polarization memory effect for holes with up to 0.1 degree of polarization. Furthermore, investigations of the time dynamics of the hole spin relaxation reveal surprisingly long lifetimes T1h in the microsecond range, therefore, comparable with electron spin

  5. Centre for nuclear engineering University of Toronto annual report 1984

    International Nuclear Information System (INIS)

    The annual report of the Centre for Nuclear Engineering, University of Toronto covers the following subjects: message from the Dean; Chairman's message; origins of the centre; formation of the centre; new nuclear appointments; and activities of the centre, 1984

  6. Luminescent Surface Quaternized Carbon Dots

    KAUST Repository

    Bourlinos, Athanasios B.

    2012-01-10

    Thermal oxidation of a salt precursor made from the acid base combination of tris(hydroxymethyl)aminomethane and betaine hydrochloride results in light-emitting surface quaternized carbon dots that are water-dispersible, display anion exchange properties, and exhibit uniform size/surface charge. © 2011 American Chemical Society.

  7. On triaxial ellipsoidal quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Voon, L C Lew Yan; Willatzen, M [Mads Clausen Institute, University of Southern Denmark, Grundtvigs Alle 150, DK-6400 Soenderborg (Denmark)

    2004-02-25

    The bound-state problem for triaxial ellipsoidal infinite-barrier quantum dots has been solved. It is exactly solvable in terms of ellipsoidal coordinates and the eigenmodes are written in terms of Lame wavefunctions. The need for all eight types of functions is shown. This presents a generalization over previous work on spheres and spheroids. Splitting of degeneracy and level crossing are obtained.

  8. DOT strategies versus orbiter strategies

    NARCIS (Netherlands)

    Rutten, R.J.

    2001-01-01

    The Dutch Open Telescope is a high-resolution solar imager coming on-line at La Palma. The definition of the DOT science niche, strategies, and requirements resemble Solar Orbiter considerations and deliberations. I discuss the latter in the light of the former, and claim that multi-line observation

  9. Vertical asymmetric double quantum dots

    Science.gov (United States)

    Roßbach, R.; Reischle, M.; Beirne, G. J.; Schweizer, H.; Jetter, M.; Michler, P.

    2007-01-01

    Two layers of differently sized self-assembled InP-quantum dots (QDs) separated by a GaInP spacer layer with varying thickness were grown by metal organic vapor phase epitaxy (MOVPE). Photoluminescence measurements of the QD ensembles and of individual asymmetric double QDS show coupling due to the tunnelling of carriers.

  10. Powering the Future Data Centre

    DEFF Research Database (Denmark)

    Zhang, Zhe

    2010-01-01

    The extended run Uninterruptible Power Supply system (UPSs) which powered by fuel cells and supercapcitors, is a promising solution for future data centre to obtain environmentfriendly energy efficient and cost effective. There are many challenges in power electronic interface circuits, because......: • Optimized design method for dual active bridge (DAB) converter and its derived circuits; • A novel hybrid dc-dc converter and its corresponding optimal design method are proposed; • An improved dual input current-fed DC-DC converter with bidirectional power conversion ability is investigated; • Extend...... the circuit level decoupling modulation scheme into 3LNPC inverter. As to the DAB converter, through the power factor and harmonics analysis, the dominated loss factor is found in variable input voltage range. Optimized parameter choosing method is used to decide the ac inductance and switching frequency...

  11. Hyperdense dots mimicking microcalcifications : Mammographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nam Hyeon; Park, Jeong Mi; Goo, Hyun Woo; Bang, Sun Woo [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    1996-12-01

    To differentiate fine hyperdense dots mimicking microcalcifications from true microcalcifications on mammography. Mammograms showing hyperdense dots in ten patients (mean age, 59 years) were evaluated. Two radiologists were asked to differentiate with the naked eye the hyperdense dots seen on ten mammograms and proven microcalcifications seen on ten mammograms. Densitometry was also performed for all lesions and the contrast index was calculated. The shape and distribution of the hyperdense dots were evaluated and enquires were made regarding any history of breast disease and corresponding treatment. Biopsies were performed for two patients with hyperdense dots. Two radiologists made correct diagnoses in 19/20 cases(95%). The contrast index was 0.10-0.88 (mean 0.58) for hyperdense dots and 0.02-0.45 (mean 0.17) for true microcalcifications. The hyperdense dots were finer and homogeneously rounder than the microcalcifications. Distribution of the hyperdense dots was more superficial in subcutaneous fat (seven cases) and subareolar area (six cases). All ten patients with hyperdense dots had history of mastitis and abscesses and had been treated by open drainage (six cases) and/or folk remedy (four cases). In eight patients, herb patches had been attached. Biopsies of hyperdense dots did not show any microcalcification or evidence of malignancy. These hyperdense dots were seen mainly in older patients. Their characteristic density, shape, distribution and clinical history makes differential diagnosis from true microcalcifications easy and could reduce unnecessary diagnostic procedures such as surgical biopsy.

  12. Hyperdense dots mimicking microcalcifications : Mammographic findings

    International Nuclear Information System (INIS)

    To differentiate fine hyperdense dots mimicking microcalcifications from true microcalcifications on mammography. Mammograms showing hyperdense dots in ten patients (mean age, 59 years) were evaluated. Two radiologists were asked to differentiate with the naked eye the hyperdense dots seen on ten mammograms and proven microcalcifications seen on ten mammograms. Densitometry was also performed for all lesions and the contrast index was calculated. The shape and distribution of the hyperdense dots were evaluated and enquires were made regarding any history of breast disease and corresponding treatment. Biopsies were performed for two patients with hyperdense dots. Two radiologists made correct diagnoses in 19/20 cases(95%). The contrast index was 0.10-0.88 (mean 0.58) for hyperdense dots and 0.02-0.45 (mean 0.17) for true microcalcifications. The hyperdense dots were finer and homogeneously rounder than the microcalcifications. Distribution of the hyperdense dots was more superficial in subcutaneous fat (seven cases) and subareolar area (six cases). All ten patients with hyperdense dots had history of mastitis and abscesses and had been treated by open drainage (six cases) and/or folk remedy (four cases). In eight patients, herb patches had been attached. Biopsies of hyperdense dots did not show any microcalcification or evidence of malignancy. These hyperdense dots were seen mainly in older patients. Their characteristic density, shape, distribution and clinical history makes differential diagnosis from true microcalcifications easy and could reduce unnecessary diagnostic procedures such as surgical biopsy

  13. Systematic safety evaluation on photoluminescent carbon dots

    Science.gov (United States)

    Wang, Kan; Gao, Zhongcai; Gao, Guo; Wo, Yan; Wang, Yuxia; Shen, Guangxia; Cui, Daxiang

    2013-03-01

    Photoluminescent carbon dots (C-dots) were prepared using the improved nitric acid oxidation method. The C-dots were characterized by tapping-mode atomic force microscopy, and UV-vis absorption spectroscopy. The C-dots were subjected to systematic safety evaluation via acute toxicity, subacute toxicity, and genotoxicity experiments (including mouse bone marrow micronuclear test and Salmonella typhimurium mutagenicity test). The results showed that the C-dots were successfully prepared with good stability, high dispersibility, and water solubility. At all studied C-dot dosages, no significant toxic effect, i.e., no abnormality or lesion, was observed in the organs of the animals. Therefore, the C-dots are non-toxic to mice under any dose and have potential use in fluorescence imaging in vivo, tumor cell tracking, and others.

  14. Spin transport through quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Lima, A.T. da Cunha; Anda, Enrique V. [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2003-07-01

    Full text: We investigate the spin polarized transport properties of a nanoscopic device constituted by a quantum dot connected to two leads. The electrical current circulates with a spin polarization that is modulated via a gate potential that controls the intensity of the spin-orbit coupling, the Rashba effect. We study a polarized field-effect transistor when one of its parts is constituted by a small quantum dot, which energies are controlled by another gate potential operating inside the confined region. The high confinement and correlation suffered by the charges inside the dot gives rise to novel phenomena. We show that through the manipulation of the gate potential applied to the dot it is possible to control, in a very efficient way, the intensity and polarization of the current that goes along the system. Other crucial parameters to be varied in order to understand the behavior of this system are the intensity of the external applied electric and magnetic field. The system is represented by the Anderson Impurity Hamiltonian summed to a spin-orbit interaction, which describes the Rashba effect. To obtain the current of this out-of-equilibrium system we use the Keldysh formalism.The solution of the Green function are compatible with the Coulomb blockade regime. We show that under the effect of a external magnetic field, if the dot is small enough the device operates as a complete spin filter that can be controlled by the gate potential. The behavior of this device when it is injected into it a polarized current and modulated by the Rashba effect is as well studied. (author)

  15. Smart work centres in rural areas

    DEFF Research Database (Denmark)

    Lorentzen, Anne Birte

    This paper discusses the establishment of telework centres as an element in local development strategies in rural areas, with a particular view to two new telework centres in region North Denmark. The paper argues that telework centres do not represent an easy solution to problems of local...... development and environmental sustainability, and further, that technology may not even be the most important feature needed to make them function as such....

  16. Activities of Radiation Protection Centre in 2000

    CERN Document Server

    Radiat. Prot. Cent. Vilnius

    2001-01-01

    Description of the activities of Radiation Protection Centre in 2000 is presented. Radiation Protection Centre is responsible for radiation protection issues. Currently there are six departments at Radiation Protection Centre: two in Vilnius - Department of Radiation Protection Supervision and Control and Department of Programs and Expertise, and four in the districts. Brief information on subject controlled by each departments is provided focusing on main achievements and events.

  17. Elm Farm Organic Research Centre December 2006

    OpenAIRE

    Sanders, Richard; Whiltley, Andrew; Haigh, Zoe; Clarke, Sarah; Hitchings, Roger; O'Brien, Josie

    2006-01-01

    The Organic Research Centre. Elm Farm Research Centre Bulletin with Technical Updates from The Organic Advisory Service is a regular publication from The Organic Research Centre. The current issue covers: Report from 2006 Cirencester Conference; Quest for more home produced organic food; in a world where bread matters; Improving wheat with plenty of parents; Unlocking the secrets of the ancient (cereal varieties); Brain food- a good read; Not to late to protect the future: The organic...

  18. Business plan – Tennis centre modernization

    OpenAIRE

    Moravec, Martin

    2012-01-01

    The goal of this master's thesis "Business plan -- Tennis centre modernization" - is creating and writing the business plan for the reconstruction of the existing tennis centre. The theoretical part describes characteristics of small and medium sized enterprises, their meaning. Describes the necessary parts of the business plan, its possible structure. The paper involves the knowledge gained into the concrete case of the tennis centre. Describes its nowadays conditions and possible solutions....

  19. The European NEO Coordination Centre

    Science.gov (United States)

    Perozzi, E.; Borgia, B.; Micheli, M.

    An operational approach to NEO (Near-Earth Object) hazard monitoring has been developed at European level within the framework of the Space Situational Awareness Program (SSA) of the European Space Agency (ESA). Through federating European assets and profiting of the expertise developed in European Universities and Research Centers, it has been possible to start the deployment of the so-called SSA NEO Segment. This initiative aims to provide a significant contribution to the worldwide effort to the discovery, follow-up and characterization of the near-Earth object population. A major achievement has been the inauguration in May 2013 of the ESA NEO Coordination Centre located at ESRIN (Frascati, Italy). The goal of the NEOCC Precursor Service operations is twofold: to make available updated information on the NEO population and the associated hazard and to contribute to optimize the NEO observational efforts. This is done by maintaining and improving a Web Portal publicly available at http://neo.ssa.esa.int and by performing follow-up observations through a network of collaborating telescopes and facilities. An overview of the SSA-NEO System and a summary of the first two years of NEOCC operations is presented.

  20. Laparoscopic adrenalectomy: Single centre experience.

    LENUS (Irish Health Repository)

    O'Farrell, N J

    2012-02-01

    BACKGROUND: Laparoscopic adrenalectomy is an attractive alternative to the traditional open approach in the surgical excision of an adrenal gland. It has replaced open adrenalectomy in our institution and we review our experience to date. METHODS: All cases of laparoscopic adrenalectomies in our hospital over eight years (from 2001 to May 2009) were retrospectively reviewed. Patient demographics, diagnosis, length of hospital stay, histology and all operative and post-operative details were evaluated. RESULTS: Fifty-five laparoscopic adrenalectomies (LA) were performed on 51 patients over eight years. The mean age was 48 years (Range 16-86 years) with the male: female ratio 1:2. Twenty-three cases had a right adrenalectomy, 24 had a left adrenalectomy and the remaining four patients had bilateral adrenalectomies. 91% were successfully completed laparoscopically with five converted to an open approach. Adenomas (functional and non functional) were the leading indication for LA, followed by phaeochromocytomas. Other indications for LA included Cushing\\'s disease, adrenal malignancies and rarer pathologies. There was one mortality from necrotising pancreatitis following a left adrenalectomy for severe Cushing\\'s disease, with subsequent death 10 days later. CONCLUSION: Laparoscopic adrenalectomy is effective for the treatment of adrenal tumours, fulfilling the criteria for the ideal minimally invasive procedure. It has replaced the traditional open approach in our centre and is a safe and effective alternative. However, in the case of severe Cushing\\'s disease, laparoscopic adrenalectomy has the potential for significant adverse outcomes and mortality.

  1. Oil Trading Centre to Reopen in Shanghai

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Chinese oil companies will likely resume activities at the oil trading centre in Shanghai this year, a move to further liberalize the once tightly controlled oil market. The centre will trade forward contracts for refined oil products,including gasoline, diesel oil, kerosene and fuel oil, industrial sources said.

  2. Danish Anaesthesia Allergy Centre - preliminary results

    DEFF Research Database (Denmark)

    Garvey, L H; Roed-Petersen, J; Menné, T;

    2001-01-01

    BACKGROUND: Anaphylactoid reactions in anaesthesia are rare and should ideally be investigated in specialist centres. At Gentofte University Hospital, we established such a centre in 1998 as a joint venture between the Departments of Anaesthesiology and Dermatology. We present the methodology...

  3. Neighbourhood Centres – Organisation, Management and Finance

    DEFF Research Database (Denmark)

    Larsen, Jacob Norvig

    From the late 1990s neighbourhood centres were brought to the fore of public urban regen-eration policy, because they were seen as a means to accelerate the formation of social capital in deprived urban neighbourhoods. A number of such local community centres were established with substantial pub...

  4. Constructions from Dots and Lines

    CERN Document Server

    Rodriguez, Marko A

    2010-01-01

    A graph is a data structure composed of dots (i.e. vertices) and lines (i.e. edges). The dots and lines of a graph can be organized into intricate arrangements. The ability for a graph to denote objects and their relationships to one another allow for a surprisingly large number of things to be modeled as a graph. From the dependencies that link software packages to the wood beams that provide the framing to a house, most anything has a corresponding graph representation. However, just because it is possible to represent something as a graph does not necessarily mean that its graph representation will be useful. If a modeler can leverage the plethora of tools and algorithms that store and process graphs, then such a mapping is worthwhile. This article explores the world of graphs in computing and exposes situations in which graphical models are beneficial.

  5. The role of the sexual assault centre.

    LENUS (Irish Health Repository)

    Eogan, Maeve

    2013-02-01

    Sexual Assault Centres provide multidisciplinary care for men and women who have experienced sexual crime. These centres enable provision of medical, forensic, psychological support and follow-up care, even if patients chose not to report the incident to the police service. Sexual Support Centres need to provide a ring-fenced, forensically clean environment. They need to be appropriately staffed and available 24 hours a day, 7 days a week to allow prompt provision of medical and supportive care and collection of forensic evidence. Sexual Assault Centres work best within the context of a core agreed model of care, which includes defined multi-agency guidelines and care pathways, close links with forensic science and police services, and designated and sustainable funding arrangements. Additionally, Sexual Assault Centres also participate in patient, staff and community education and risk reduction. Furthermore, they contribute to the development, evaluation and implementation of national strategies on domestic, sexual and gender-based violence.

  6. Photoactivation of silicon quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Lockwood, R., E-mail: rossl@ualberta.c [Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2G7 (Canada); McFarlane, S. [Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2G7 (Canada); Rodriguez Nunez, J.R. [Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada); Wang, X.Y. [Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2G7 (Canada); Veinot, J.G.C. [Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada); Meldrum, A. [Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2G7 (Canada)

    2011-07-15

    We show that free-standing silicon quantum dots (QDs) can be photoactivated by blue or UV optical irradiation. The luminescence intensity increases by an order of magnitude for irradiation times of several minutes under moderate optical power. The cut-off energy for photoactivation is between 2.1 and 2.4 eV, not very different from the activation energy for hydrogen dissociation from bulk silicon surfaces. We propose the mechanism for this effect is associated with silicon-hydride bond breaking and the subsequent oxidation of dangling bonds. This phenomenon could be used to 'write' luminescent quantum dots into pre-determined arrays. - Research highlights: {yields}Laser light causes increased photoluminescence intensity in silicon quantum dots. {yields} The photoactivation process is effective for wavelengths of 514 nm and shorter. {yields} Hydrogen bound to the Si-QDs is replaced by oxygen in a two-step process. {yields} Patterning is possible but limited by physical dispersion of Si-QDs.

  7. Few-electron quantum dots

    International Nuclear Information System (INIS)

    We review some electron transport experiments on few-electron, vertical quantum dot devices. The measurement of current versus source-drain voltage and gate voltage is used as a spectroscopic tool to investigate the energy characteristics of interacting electrons confined to a small region in a semiconducting material. Three energy scales are distinguished: the single-particle states, which are discrete due to the confinement involved; the direct Coulomb interaction between electron charges on the dot; and the exchange interaction between electrons with parallel spins. To disentangle these energies, a magnetic field is used to reorganize the occupation of electrons over the single-particle states and to induce changes in the spin states. We discuss the interactions between small numbers of electrons (between 1 and 20) using the simplest possible models. Nevertheless, these models consistently describe a large set of experiments. Some of the observations resemble similar phenomena in atomic physics, such as shell structure and periodic table characteristics, Hund's rule, and spin singlet and triplet states. The experimental control, however, is much larger than for atoms: with one device all the artificial elements can be studied by adding electrons to the quantum dot when changing the gate voltage. (author)

  8. Near-infrared quantum dots for HER2 localization and imaging of cancer cells

    Directory of Open Access Journals (Sweden)

    Rizvi SB

    2014-03-01

    Full Text Available Sarwat B Rizvi,1 Sepideh Rouhi,1 Shohei Taniguchi,2 Shi Yu Yang,1 Mark Green,2 Mo Keshtgar,1,3 Alexander M Seifalian1,3 1UCL Centre for Nanotechnology and Regenerative Medicine, University College London, 2Department of Physics, King's College London, 3Royal Free London NHS Foundation Trust Hospital, London, UK Background: Quantum dots are fluorescent nanoparticles with unique photophysical properties that allow them to be used as diagnostic, therapeutic, and theranostic agents, particularly in medical and surgical oncology. Near-infrared-emitting quantum dots can be visualized in deep tissues because the biological window is transparent to these wavelengths. Their small sizes and free surface reactive groups that can be conjugated to biomolecules make them ideal probes for in vivo cancer localization, targeted chemotherapy, and image-guided cancer surgery. The human epidermal growth factor receptor 2 gene (HER2/neu is overexpressed in 25%–30% of breast cancers. The current methods of detection for HER2 status, including immunohistochemistry and fluorescence in situ hybridization, are used ex vivo and cannot be used in vivo. In this paper, we demonstrate the application of near-infrared-emitting quantum dots for HER2 localization in fixed and live cancer cells as a first step prior to their in vivo application. Methods: Near-infrared-emitting quantum dots were characterized and their in vitro toxicity was established using three cancer cell lines, ie, HepG2, SK-BR-3 (HER2-overexpressing, and MCF7 (HER2-underexpressing. Mouse antihuman anti-HER2 monoclonal antibody was conjugated to the near-infrared-emitting quantum dots. Results: In vitro toxicity studies showed biocompatibility of SK-BR-3 and MCF7 cell lines with near-infrared-emitting quantum dots at a concentration of 60 µg/mL after one hour and 24 hours of exposure. Near-infrared-emitting quantum dot antiHER2-antibody bioconjugates successfully localized HER2 receptors on SK-BR-3 cells

  9. Charge State Hysteresis in Semiconductor Quantum Dots

    OpenAIRE

    Yang, C. H.; Rossi, A; Lai, N. S.; Leon, R.; Lim, W. H.; Dzurak, A.S.

    2014-01-01

    Semiconductor quantum dots provide a two-dimensional analogy for real atoms and show promise for the implementation of scalable quantum computers. Here, we investigate the charge configurations in a silicon metal-oxide-semiconductor double quantum dot tunnel coupled to a single reservoir of electrons. By operating the system in the few-electron regime, the stability diagram shows hysteretic tunnelling events that depend on the history of the dots charge occupancy. We present a model which acc...

  10. Resonant electron transfer between quantum dots

    OpenAIRE

    Openov, Leonid A.

    1999-01-01

    An interaction of electromagnetic field with a nanostructure composed of two quantum dots is studied theoretically. An effect of a resonant electron transfer between the localized low-lying states of quantum dots is predicted. A necessary condition for such an effect is the existence of an excited bound state whose energy lies close to the top of the barrier separating the quantum dots. This effect may be used to realize the reversible quantum logic gate NOT if the superposition of electron s...

  11. Optical Fiber Sensing Using Quantum Dots

    Directory of Open Access Journals (Sweden)

    Faramarz Farahi

    2007-12-01

    Full Text Available Recent advances in the application of semiconductor nanocrystals, or quantumdots, as biochemical sensors are reviewed. Quantum dots have unique optical properties thatmake them promising alternatives to traditional dyes in many luminescence basedbioanalytical techniques. An overview of the more relevant progresses in the application ofquantum dots as biochemical probes is addressed. Special focus will be given toconfigurations where the sensing dots are incorporated in solid membranes and immobilizedin optical fibers or planar waveguide platforms.

  12. Big Surveys, Big Data Centres

    Science.gov (United States)

    Schade, D.

    2016-06-01

    Well-designed astronomical surveys are powerful and have consistently been keystones of scientific progress. The Byurakan Surveys using a Schmidt telescope with an objective prism produced a list of about 3000 UV-excess Markarian galaxies but these objects have stimulated an enormous amount of further study and appear in over 16,000 publications. The CFHT Legacy Surveys used a wide-field imager to cover thousands of square degrees and those surveys are mentioned in over 1100 publications since 2002. Both ground and space-based astronomy have been increasing their investments in survey work. Survey instrumentation strives toward fair samples and large sky coverage and therefore strives to produce massive datasets. Thus we are faced with the "big data" problem in astronomy. Survey datasets require specialized approaches to data management. Big data places additional challenging requirements for data management. If the term "big data" is defined as data collections that are too large to move then there are profound implications for the infrastructure that supports big data science. The current model of data centres is obsolete. In the era of big data the central problem is how to create architectures that effectively manage the relationship between data collections, networks, processing capabilities, and software, given the science requirements of the projects that need to be executed. A stand alone data silo cannot support big data science. I'll describe the current efforts of the Canadian community to deal with this situation and our successes and failures. I'll talk about how we are planning in the next decade to try to create a workable and adaptable solution to support big data science.

  13. The Canadian Astronomy Data Centre

    Science.gov (United States)

    Ball, Nicholas M.; Schade, D.; Astronomy Data Centre, Canadian

    2011-01-01

    The Canadian Astronomy Data Centre (CADC) is the world's largest astronomical data center, holding over 0.5 Petabytes of information, and serving nearly 3000 astronomers worldwide. Its current data collections include BLAST, CFHT, CGPS, FUSE, Gemini, HST, JCMT, MACHO, MOST, and numerous other archives and services. It provides extensive data archiving, curation, and processing expertise, via projects such as MegaPipe, and enables substantial day-to-day collaboration between resident astronomers and computer specialists. It is a stable, powerful, persistent, and properly supported environment for the storage and processing of large volumes of data, a condition that is now absolutely vital for their science potential to be exploited by the community. Through initiatives such as the Common Archive Observation Model (CAOM), the Canadian Virtual Observatory (CVO), and the Canadian Advanced Network for Astronomical Research (CANFAR), the CADC is at the global forefront of advancing astronomical research through improved data services. The CAOM aims to provide homogeneous data access, and hence viable interoperability between a potentially unlimited number of different data collections, at many wavelengths. It is active in the definition of numerous emerging standards within the International Virtual Observatory, and several datasets are already available. The CANFAR project is an initiative to make cloud computing for storage and data-intensive processing available to the community. It does this via a Virtual Machine environment that is equivalent to managing a local desktop. Several groups are already processing science data. CADC is also at the forefront of advanced astronomical data analysis, driven by the science requirements of astronomers both locally and further afield. The emergence of 'Astroinformatics' promises to provide not only utility items like object classifications, but to directly enable new science by accessing previously undiscovered or intractable

  14. Activation of silicon quantum dots for emission

    Institute of Scientific and Technical Information of China (English)

    Huang Wei-Qi; Miao Xin-Jian; Huang Zhong-Mei; Liu Shi-Rong; Qin Chao-Jian

    2012-01-01

    The emission of silicon quantum dots is weak when their surface is passivated well. Oxygen or nitrogen on the surface of silicon quantum dots can break the passivation to form localized electronic states in the band gap to generate active centers where stronger emission occurs.From this point of view,we can build up radiative matter for emission.Emissions of various wavelengths can be obtained by controlling the surface bonds of silicon quantum dots.Our experimental results demonstrate that annealing is important in the treatment of the activation,and stimulated emissions at about 600 and 700 nm take place on active silicon quantum dots.

  15. Thermoelectric energy harvesting with quantum dots.

    Science.gov (United States)

    Sothmann, Björn; Sánchez, Rafael; Jordan, Andrew N

    2015-01-21

    We review recent theoretical work on thermoelectric energy harvesting in multi-terminal quantum-dot setups. We first discuss several examples of nanoscale heat engines based on Coulomb-coupled conductors. In particular, we focus on quantum dots in the Coulomb-blockade regime, chaotic cavities and resonant tunneling through quantum dots and wells. We then turn toward quantum-dot heat engines that are driven by bosonic degrees of freedom such as phonons, magnons and microwave photons. These systems provide interesting connections to spin caloritronics and circuit quantum electrodynamics.

  16. POLARON IN CYLINDRICAL AND SPHERICAL QUANTUM DOTS

    Directory of Open Access Journals (Sweden)

    L.C.Fai

    2004-01-01

    Full Text Available Polaron states in cylindrical and spherical quantum dots with parabolic confinement potentials are investigated applying the Feynman variational principle. It is observed that for both kinds of quantum dots the polaron energy and mass increase with the increase of Frohlich electron-phonon coupling constant and confinement frequency. In the case of a spherical quantum dot, the polaron energy for the strong coupling is found to be greater than that of a cylindrical quantum dot. The energy and mass are found to be monotonically increasing functions of the coupling constant and the confinement frequency.

  17. Semiconductor quantum-dot lasers and amplifiers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Borri, Paola; Ledentsov, N. N.;

    2002-01-01

    -power surface emitting VCSELs. We investigated the ultrafast dynamics of quantum-dot semiconductor optical amplifiers. The dephasing time at room temperature of the ground-state transition in semiconductor quantum dots is around 250 fs in an unbiased amplifier, decreasing to below 50 fs when the amplifier...... is biased to positive net gain. We have further measured gain recovery times in quantum dot amplifiers that are significantly lower than in bulk and quantum-well semiconductor optical amplifiers. This is promising for future demonstration of quantum dot devices with high modulation bandwidth...

  18. Sensitisation of visible and NIR lanthanide emission by InPZnS quantum dots in bi-luminescent hybrids.

    Science.gov (United States)

    Molloy, Jennifer K; Lincheneau, Christophe; Karimdjy, Maria Moula; Agnese, Fabio; Mattera, Lucia; Gateau, Christelle; Reiss, Peter; Imbert, Daniel; Mazzanti, Marinella

    2016-03-25

    The synthesis of stable hybrid nanoparticles combining InPZnS@ZnSe/ZnS quantum dots (QDs) and grafted lanthanide complexes has been performed using two different approaches in organic and aqueous media. The final bi-luminescent hybrids exhibit Ln(III) (Ln = Eu and Yb) centred luminescence upon QD excitation, suggesting that an energy transfer occurs from the QD to the lanthanide. PMID:26941180

  19. Synthesis and application of luminescent single CdS quantum dot encapsulated silica nanoparticles directed for precision optical bioimaging

    OpenAIRE

    Veeranarayanan S; Poulose AC; Mohamed MS; Nagaoka Y; Iwai S.; Nakagame Y; Kashiwada S; Yoshida Y; Maekawa T; Kumar DS

    2012-01-01

    Srivani Veeranarayanan, Aby Cheruvathoor Poulose, M Sheikh Mohamed, Yutaka Nagaoka, Seiki Iwai, Yuya Nakagame, Shosaku Kashiwada, Yasuhiko Yoshida, Toru Maekawa, D Sakthi KumarBio Nano Electronics Research Centre, Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, JapanAbstract: This paper presents the synthesis of aqueous cadmium sulfide (CdS) quantum dots (QDs) and silica-encapsulated CdS QDs by reverse microemulsion method and utilized as targeted bio-optical probe...

  20. From micro- to nanomagnetic dots: evolution of the eigenmode spectrum on reducing the lateral size

    Science.gov (United States)

    Carlotti, G.; Gubbiotti, G.; Madami, M.; Tacchi, S.; Hartmann, F.; Emmerling, M.; Kamp, M.; Worschech, L.

    2014-07-01

    Brillouin light scattering experiments and micromagnetic simulations have been exploited to investigate the spectrum of thermally excited magnetic eigenmodes in 10 nm-thick elliptical Permalloy dots, when the longer axis D is scaled down from about 1000 to 100 nm. It is shown that for D larger than about 200 nm the characteristics of the spin-wave eigenmodes are dominated by dipolar energy, while for D in the range of about 100 to 200 nm exchange energy effects cause qualitative and quantitative differences in the spin-wave spectrum. In this ‘mesoscopic’ regime, the usual classification scheme, involving one fundamental mode with large average magnetization and many other modes collected in families with specific symmetries, no longer holds. Rather, one finds the simultaneous presence of two modes with ‘fundamental’ character, i.e. with a significant and comparable value of the average dynamical magnetization: the former is at larger frequency and has its maximum amplitude at the dot's centre, while the latter occurs at lower frequency and is localized at the dot's edges. Interestingly, the maximum intensity swaps from the higher frequency mode to the lower frequency one, just when the dot size is reduced from about 200 to 100 nm. This is relevant in view of the exploitation of nanodots for the design of nanomagnetic devices with lateral dimensions in the above interval, such as memory cells, logic gates, reading heads and spin-torque oscillators.

  1. Review of CERN Data Centre Infrastructure

    CERN Document Server

    Andrade, P; van Eldik, J; McCance, G; Panzer-Steindel, B; Coelho dos Santos, M; Traylen, S; Schwickerath, U

    2012-01-01

    The CERN Data Centre is reviewing strategies for optimizing the use of the existing infrastructure and expanding to a new data centre by studying how other large sites are being operated. Over the past six months, CERN has been investigating modern and widely-used tools and procedures used for virtualisation, clouds and fabric management in order to reduce operational effort, increase agility and support unattended remote data centres. This paper gives the details on the project’s motivations, current status and areas for future investigation.

  2. Review of CERN Data Centre Infrastructure

    Science.gov (United States)

    Andrade, P.; Bell, T.; van Eldik, J.; McCance, G.; Panzer-Steindel, B.; Coelho dos Santos, M.; Traylen and, S.; Schwickerath, U.

    2012-12-01

    The CERN Data Centre is reviewing strategies for optimizing the use of the existing infrastructure and expanding to a new data centre by studying how other large sites are being operated. Over the past six months, CERN has been investigating modern and widely-used tools and procedures used for virtualisation, clouds and fabric management in order to reduce operational effort, increase agility and support unattended remote data centres. This paper gives the details on the project's motivations, current status and areas for future investigation.

  3. Quantum Dot Spectrum Converters for Enhanced High Efficiency Photovoltaics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This research proposes to enhance solar cell efficiency, radiation resistance and affordability. The Quantum Dot Spectrum Converter (QDSC) disperses quantum dots...

  4. Towards Human-Centred Design

    Science.gov (United States)

    Bannon, Liam J.

    The field of HCI has evolved and expanded dramatically since its origin in the early 1980’s. The HCI community embraces a large community of researchers and practitioners around the world, from a variety of disciplinary backgrounds in the human and social sciences, engineering and informatics, and more recently, the arts and design disciplines. This kaleidoscope of cultures and disciplines as seen at INTERACT Conferences provides a rich pool of resources for examining our field. Applications are increasingly exploring our full range of sensory modalities, and merging the digital and physical worlds. WiFi has opened up a huge design space for mobile applications. A focus on usability of products and services has been complemented by an emphasis on engagement, enjoyment and experience. With the advent of ubiquitous computing, and the emergence of “The Internet of Things”, new kinds of more open infrastructures make possible radically new kinds of applications. The sources of innovation have also broadened, to include human and social actors outside of the computing and design organizations. The question is to what extent is our mainstream thinking in the HCI field ready for the challenges of this Brave New World? Do the technological and social innovations that we see emerging require us to re-shape, or even, re-create, our field, or is it a case of a more gradual evolution and development of that which we already know? In this closing Keynote, I will provide a perspective on the evolution and development of the HCI field, looking backwards as well as forwards, in order to determine what are some of the changes of significance in the field. This “broad-brush” approach to what I term “ human-centred design” will be complemented by the examination of specific projects and applications, to help anchor some of the discussion. Areas such as user-centred design, participatory design, computer-supported cooperative work and learning, and interaction design, in

  5. Quantum Gates Between Two Spins in a Triple Dot System with an Empty Dot

    CERN Document Server

    Coello, Jose Garcia

    2011-01-01

    We propose a scheme for implementing quantum gates and entanglement between spin qubits in the outer dots of a triple-dot system with an empty central dot. The voltage applied to the central dot can be tuned to realize the gate. Our scheme exemplifies the possibility of quantum gates outside the regime where each dot has an electron, so that spin-spin exchange interaction is not the only relevant mechanism. Analytic treatment is possible by mapping the problem to a t-J model. The fidelity of the entangling quantum gate between the spins is analyzed in the presence of decoherence stemming from a bath of nuclear spins, as well as from charge fluctuations. Our scheme provides an avenue for extending the scope of two qubit gate experiments to triple-dots, while requiring minimal control, namely that of the potential of a single dot, and may enhance the qubit separation to ease differential addressability.

  6. Nitrogen-Doped Carbon Dots for "green" Quantum Dot Solar Cells.

    Science.gov (United States)

    Wang, Hao; Sun, Pengfei; Cong, Shan; Wu, Jiang; Gao, Lijun; Wang, Yun; Dai, Xiao; Yi, Qinghua; Zou, Guifu

    2016-12-01

    Considering the environment protection, "green" materials are increasingly explored for photovoltaics. Here, we developed a kind of quantum dots solar cell based on nitrogen-doped carbon dots. The nitrogen-doped carbon dots were prepared by direct pyrolysis of citric acid and ammonia. The nitrogen-doped carbon dots' excitonic absorption depends on the N-doping content in the carbon dots. The N-doping can be readily modified by the mass ratio of reactants. The constructed "green" nitrogen-doped carbon dots solar cell achieves the best power conversion efficiency of 0.79 % under AM 1.5 G one full sun illumination, which is the highest efficiency for carbon dot-based solar cells. PMID:26781285

  7. Symmetric centres of braided monoidal categories

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper introduces the concept of‘symmetric centres' of braided monoidal categories. Let H be a Hopf algebra with bijective antipode over a field k. We address the symmetric centre of the Yetter-Drinfel'd module category HH(yD) and show that a left Yetter-Drinfel'd module M belongs to the symmetric centre of HH(yD) if and only if M is trivial. We also study the symmetric centres of categories of representations of quasitriangular Hopf algebras and give a sufficient and necessary condition for the braid of H(M) to induce the braid of (H(H)(A),(○)A,A,φ,l,r), or equivalently, the braid of (A#H(H),(○)A,A,φ,l,r), where A is a quantum commutative H-module algebra.

  8. Photoinduced electron transfers with carbon dots

    OpenAIRE

    Wang, Xin; Cao, Li; Lu, Fushen; Meziani, Mohammed J.; Li, Heting; Qi, Gang; Zhou, Bing; Harruff, Barbara A.; Kermarrec, Fabien; Sun, Ya-Ping

    2009-01-01

    The photoluminescence in carbon dots (surface-passivated small carbon nanoparticles) could be quenched efficiently by electron acceptor or donor molecules in solution, namely that photo-excited carbon dots are both excellent electron donors and excellent electron acceptors, thus offering new opportunities for their potential uses in light energy conversion and related applications.

  9. Thick-shell nanocrystal quantum dots

    Science.gov (United States)

    Hollingsworth, Jennifer A.; Chen, Yongfen; Klimov, Victor I.; Htoon, Han; Vela, Javier

    2011-05-03

    Colloidal nanocrystal quantum dots comprising an inner core having an average diameter of at least 1.5 nm and an outer shell, where said outer shell comprises multiple monolayers, wherein at least 30% of the quantum dots have an on-time fraction of 0.80 or greater under continuous excitation conditions for a period of time of at least 10 minutes.

  10. Optical Properties of Semiconductor Quantum Dots

    NARCIS (Netherlands)

    Perinetti, U.

    2011-01-01

    This thesis presents different optical experiments performed on semiconductor quantum dots. These structures allow to confine a small number of electrons and holes to a tiny region of space, some nm across. The aim of this work was to study the basic properties of different types of quantum dots mad

  11. Detecting the chirality for coupled quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Cao Huijuan [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510631 (China); Hu Lian [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510631 (China)], E-mail: huliancaohj@yahoo.com

    2008-04-21

    We propose a scheme to detect the chirality for a system consisting of three coupled quantum dots. The chirality is found to be determined by the frequency of the transition between chiral states under the chiral symmetry broken perturbation. The results are important to construct quantum gates and to demonstrate chiral entangle states in the triangle spin dots.

  12. Double Acceptor Interaction in Semimagnetic Quantum Dot

    Directory of Open Access Journals (Sweden)

    A. Merwyn Jasper D. Reuben

    2011-01-01

    Full Text Available The effect of geometry of the semimagnetic Quantum Dot on the Interaction energy of a double acceptor is computed in the effective mass approximation using the variational principle. A peak is observed at the lower dot sizes as a magnetic field is increased which is attributed to the reduction in confinement.

  13. The relativistic two-centre continuum

    International Nuclear Information System (INIS)

    A method is presented to define unique continuum states for the two-centre Dirac Hamiltonian. In the spherical limit these states become the familiar angular momentum eigenstates of the radial Coulomb potential. The different states for a fixed total energy vertical strokeEvertical stroke > m may be distinguished by considering the asymptotic spin-angular distribution of states with unique scattering-phases. First numerical solutions of the two-centre Dirac equation for continuum states are presented. (orig.)

  14. INFOTERM – Information Disseminating Centre for Terminology

    OpenAIRE

    Albina Auksoriūtė

    2014-01-01

    International Information Centre for Terminology (INFOTERM) was founded in 1971 by contract with the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the Austrian Standards Institute (ASI). In 1996, INFOTERM was reorganized and established as an independent non-profit organization. INFOTERM promotes and supports the cooperation of existing and the establishment of new terminology centres and networks with the general aim to improve domain communication, knowledge ...

  15. Two centre problems in relativistic atomic physics

    OpenAIRE

    McConnell, Sean R.

    2012-01-01

    The work contained within this thesis is concerned with the explanation and usage of a set of theoretical procedures for the study of static and dynamic two–centre problems in the relativistic framework of Dirac’s equation. Two distinctly different theories for handling time–dependent atomic interactions are reviewed, namely semi–classical perturbation theory and a non–perturbative numerical technique based on the coupled channel equation to directly solve the time–dependent, two–centre Dirac...

  16. Joint Research Centre. Ispra establishment-Italy

    International Nuclear Information System (INIS)

    A comprehensive review of the work carried out during 1974 and 1975 in the Ispra establishment of the Joint Research Centre is presented. A description of the activity carried out within the context of the running programmes is given. Some of the most relevant scientific and technical achievement are described from the viewpoints of the Scientific Departments of the Centre. The technical and administrative support activities are also presented. A list of publications issued by the Ispra Scientific staff is given

  17. Social innovation for People-Centred Development

    DEFF Research Database (Denmark)

    Hulgård, Lars; P.K., Shajahan

    2013-01-01

    Social innovation is closely related to the people-centred development (PCD) framework of knowledge production. The discussion of PCD in this chapter particularly expands on the feature of empowerment and socio-political mobilization of people in social innovation......Social innovation is closely related to the people-centred development (PCD) framework of knowledge production. The discussion of PCD in this chapter particularly expands on the feature of empowerment and socio-political mobilization of people in social innovation...

  18. Perspectives on recycling centres and future developments.

    Science.gov (United States)

    Engkvist, I-L; Eklund, J; Krook, J; Björkman, M; Sundin, E

    2016-11-01

    The overall aim of this paper is to draw combined, all-embracing conclusions based on a long-term multidisciplinary research programme on recycling centres in Sweden, focussing on working conditions, environment and system performance. A second aim is to give recommendations for their development of new and existing recycling centres and to discuss implications for the future design and organisation. Several opportunities for improvement of recycling centres were identified, such as design, layout, ease with which users could sort their waste, the work environment, conflicting needs and goals within the industry, and industrialisation. Combining all results from the research, which consisted of different disciplinary aspects, made it possible to analyse and elucidate their interrelations. Waste sorting quality was recognized as the most prominent improvement field in the recycling centre system. The research identified the importance of involving stakeholders with different perspectives when planning a recycling centre in order to get functionality and high performance. Practical proposals of how to plan and build recycling centres are given in a detailed checklist. PMID:26826952

  19. Medication errors: pharmacovigilance centres in detection and prevention

    OpenAIRE

    Bencheikh, Rachida Soulaymani; Benabdallah, Ghita

    2009-01-01

    Detecting medication errors needs collaboration between various organizations, such as patient safety institutions, pharmacovigilance centres, and poison control centres. In order to evaluate the input of pharmacovigilance centres and poison control centres in detecting and evaluating medication errors a pilot project was initiated by the World Alliance for Patient Safety in collaboration with the Uppsala Monitoring Centre; the Moroccan pharmacovigilance centre acted as project coordinator. A...

  20. Model-based clustered-dot screening

    Science.gov (United States)

    Kim, Sang Ho

    2006-01-01

    I propose a halftone screen design method based on a human visual system model and the characteristics of the electro-photographic (EP) printer engine. Generally, screen design methods based on human visual models produce dispersed-dot type screens while design methods considering EP printer characteristics generate clustered-dot type screens. In this paper, I propose a cost function balancing the conflicting characteristics of the human visual system and the printer. By minimizing the obtained cost function, I design a model-based clustered-dot screen using a modified direct binary search algorithm. Experimental results demonstrate the superior quality of the model-based clustered-dot screen compared to a conventional clustered-dot screen.

  1. Substitutional impurity in the graphene quantum dots

    Science.gov (United States)

    Sierański, K.; Szatkowski, J.

    2015-09-01

    The process of formation of the localized defect states due to substitutional impurity in sp2-bonded graphene quantum dot is considered using a simple tight-binding-type calculation. We took into account the interaction of the quantum dot atoms surrounding the substitutional impurity from the second row of elements. To saturate the external dangling sp2 orbitals of the carbon additionally 18 hydrogen atoms were introduced. The chemical formula of the quantum dot is H18C51X, where X is the symbol of substitutional atom. The position of the localized levels is determined relative to the host-atoms (C) εp energies. We focused on the effect of substitutional doping by the B, N and O on the eigenstate energies and on the total energy change of the graphene dots including for O the effect of lattice distorsion. We conclude that B, N, and O can form stable substitutional defects in graphene quantum dot.

  2. Electron transport in quantum dots

    CERN Document Server

    2003-01-01

    When I was contacted by Kluwer Academic Publishers in the Fall of 200 I, inviting me to edit a volume of papers on the issue of electron transport in quantum dots, I was excited by what I saw as an ideal opportunity to provide an overview of a field of research that has made significant contributions in recent years, both to our understanding of fundamental physics, and to the development of novel nanoelectronic technologies. The need for such a volume seemed to be made more pressing by the fact that few comprehensive reviews of this topic have appeared in the literature, in spite of the vast activity in this area over the course of the last decade or so. With this motivation, I set out to try to compile a volume that would fairly reflect the wide range of opinions that has emerged in the study of electron transport in quantum dots. Indeed, there has been no effort on my part to ensure any consistency between the different chapters, since I would prefer that this volume instead serve as a useful forum for the...

  3. Transmission of HIV in dialysis centre.

    Science.gov (United States)

    Velandia, M; Fridkin, S K; Cárdenas, V; Boshell, J; Ramirez, G; Bland, L; Iglesias, A; Jarvis, W

    1995-06-01

    In August, 1993, 13 dialysis patients at one dialysis centre in Colombia, South America, were found to be HIV positive, and this prompted an epidemiological investigation. We carried out a cohort study of all dialysis centre patients during January, 1992 to December, 1993 (epidemic period) to determine risk factors for HIV seroconversion. Haemodialysis and medical records were reviewed, dialysis centre staff and surviving patients were interviewed, and dialysis practices were observed. Stored sera from all dialysis centre patients were tested for HIV antibody. 12 (52%) of 23 patients tested positive for HIV antibody by enzyme immunoassay and western blot during the epidemic period. Of the 23 tested, 9 (39%) converted from HIV antibody negative to positive (seroconverters) and 10 (44%) remained HIV negative (seronegatives). The HIV seroconversion rate was higher among patients dialysed at the centre while a new patient, who was HIV seropositive, was dialysed there (90% vs 0%; p dialysis centre reprocessed access needles, dialysers, and bloodlines (60% vs 0%). While 2 of 9 HIV seroconverters had had sex with prostitutes, none had received unscreened blood products or had other HIV risk factors. No surgical or dental procedures were associated with HIV seroconversion. Dialysers were reprocessed separately with 5% formaldehyde and were labelled for use on the same patient. Access needles were reprocessed by soaking them in a common container with a low-level disinfectant, benzalkonium chloride; 4 pairs of needles were placed in one pan creating the potential for cross-contamination or use of one patient's needles on another patient. HIV transmission at the dialysis centre was confirmed. Improperly reprocessed patient-care equipment, most probably access needles, is the likely mechanism of transmission. This outbreak was discovered by accident and similar transmission may be occurring in many other countries where low-level disinfectants are used to sterilise critical

  4. Scavenger hunt in the CERN Computing Centre

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Hidden among the racks of servers and disks in the CERN Computing Centre, you’ll find Hawaiian dancers, space aliens, gorillas… all LEGO® figurines! These characters were placed about the Centre for the arrival of Google’s Street View team for the world to discover.   PLEASE NOTE THAT THE COMPETITION IS OVER. ONLY FOR REFERENCE, HERE IS THE ORIGINAL ARTICLE. We’re pleased to announce our first global scavenger hunt! Spot three LEGO® figurines using Google’s Street View and you’ll be entered to win a gift of your choice from our CERN Gift Guide. A LEGO® figurine in the CERN Computing Centre, as seen on Google Street View. Here are the details: Find at least three LEGO® figurines hidden around the CERN Computing Centre using Google Street View.   Take screencaps of the figurines and e-mail the pictures to TreasureHunt-ComputingCentre@cern.ch. This email is no longer active.   The...

  5. Visits to Tier-1 Computing Centres

    CERN Multimedia

    Dario Barberis

    At the beginning of 2007 it became clear that an enhanced level of communication is needed between the ATLAS computing organisation and the Tier-1 centres. Most usual meetings are ATLAS-centric and cannot address the issues of each Tier-1; therefore we decided to organise a series of visits to the Tier-1 centres and focus on site issues. For us, ATLAS computing management, it is most useful to realize how each Tier-1 centre is organised, and its relation to the associated Tier-2s; indeed their presence at these visits is also very useful. We hope it is also useful for sites... at least, we are told so! The usual participation includes, from the ATLAS side: computing management, operations, data placement, resources, accounting and database deployment coordinators; and from the Tier-1 side: computer centre management, system managers, Grid infrastructure people, network, storage and database experts, local ATLAS liaison people and representatives of the associated Tier-2s. Visiting Tier-1 centres (1-4). ...

  6. The Aube centre. 1997 statement; Le centre de l`Aube. Bilan 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    Since January 1992 the Aube centre ensures the storage of 90% of the short life radioactive wastes produced in France. This educational booklet describes the organization of the activities in the centre from the storage of wastes to the radioactivity surveillance of the environment (air, surface and ground waters, river sediments, plants and milk). (J.S.)

  7. Quantum Dots Investigated for Solar Cells

    Science.gov (United States)

    Bailey, Sheila G.; Castro, Stephanie L.; Raffaelle, Ryne P.; Hepp, Aloysius F.

    2001-01-01

    The NASA Glenn Research Center has been investigating the synthesis of quantum dots of CdSe and CuInS2 for use in intermediate-bandgap solar cells. Using quantum dots in a solar cell to create an intermediate band will allow the harvesting of a much larger portion of the available solar spectrum. Theoretical studies predict a potential efficiency of 63.2 percent, which is approximately a factor of 2 better than any state-of-the-art devices available today. This technology is also applicable to thin-film devices--where it offers a potential four-fold increase in power-to-weight ratio over the state of the art. Intermediate-bandgap solar cells require that quantum dots be sandwiched in an intrinsic region between the photovoltaic solar cell's ordinary p- and n-type regions (see the preceding figure). The quantum dots form the intermediate band of discrete states that allow sub-bandgap energies to be absorbed. However, when the current is extracted, it is limited by the bandgap, not the individual photon energies. The energy states of the quantum dot can be controlled by controlling the size of the dot. Ironically, the ground-state energy levels are inversely proportional to the size of the quantum dots. We have prepared a variety of quantum dots using the typical organometallic synthesis routes pioneered by Ba Wendi et al., in the early 1990's. The most studied quantum dots prepared by this method have been of CdSe. To produce these dots, researchers inject a syringe of the desired organometallic precursors into heated triocytlphosphine oxide (TOPO) that has been vigorously stirred under an inert atmosphere (see the following figure). The solution immediately begins to change from colorless to yellow, then orange and red/brown, as the quantum dots increase in size. When the desired size is reached, the heat is removed from the flask. Quantum dots of different sizes can be identified by placing them under a "black light" and observing the various color differences in

  8. Fluorescent Quantum Dots for Biological Labeling

    Science.gov (United States)

    McDonald, Gene; Nadeau, Jay; Nealson, Kenneth; Storrie-Lomardi, Michael; Bhartia, Rohit

    2003-01-01

    Fluorescent semiconductor quantum dots that can serve as "on/off" labels for bacteria and other living cells are undergoing development. The "on/off" characterization of these quantum dots refers to the fact that, when properly designed and manufactured, they do not fluoresce until and unless they come into contact with viable cells of biological species that one seeks to detect. In comparison with prior fluorescence-based means of detecting biological species, fluorescent quantum dots show promise for greater speed, less complexity, greater sensitivity, and greater selectivity for species of interest. There are numerous potential applications in medicine, environmental monitoring, and detection of bioterrorism.

  9. Time-bin Entanglement from Quantum Dots

    CERN Document Server

    Weihs, Gregor; Predojević, Ana

    2016-01-01

    The desire to have a source of single entangled photon pairs can be satisfied using single quantum dots as emitters. However, we are not bound to pursue only polarization entanglement, but can also exploit other degrees of freedom. In this chapter we focus on the time degree of freedom, to achieve so-called time-bin entanglement. This requires that we prepare the quantum dot coherently into the biexciton state and also build special interferometers for analysis. Finally this technique can be extended to achieve time-bin and polarization hyper-entanglement from a suitable quantum dot.

  10. Learning Styles of Independent Learning Centre Users

    Directory of Open Access Journals (Sweden)

    Tarik Uzun

    2014-09-01

    Full Text Available Learning style research has been a significant field within language teaching and learning. There have been very few attempts, however, to seek possible links between independent learning and learning style preferences. This paper aims to identify the learning styles of students who use the Independent Learning Centre (ILC on a regular basis at a state university in Turkey (n=102. The findings of the learning style analysis revealed that, contrary to expectations, most of the regular users of the centre were synoptic learners, which implies that these learners might not necessarily have conscious control over their own learning processes. An in-depth analysis of learning styles and recommendations to improve the services offered in the centre are also included in the paper.

  11. Occupational deprivation in an asylum centre:

    DEFF Research Database (Denmark)

    Morville, Anne-Le; Erlandsson, Lena-Karin

    2013-01-01

    This article presents a study of three asylum-seeking men from Iran and Afghanistan. It aimed to explore how and if they experienced occupations as occupations in a Danish asylum centre and how their life experience shaped their choice and value of current occupations. In-depth narrative interviews...... explored the participants’ occupational history and its influence on their occupations in the asylum centre. A thematic analysis showed that the participants had been subjected to occupational disruption and deprivation by politically oppressive systems even before their flight. Their occupations...... in Denmark were to a certain extent influenced by their earlier occupations and the current occupational deprivation they all experienced was due to limited possibilities in the centre. Although they tried their best to fill their days and create structure, there was a loss of valued occupations...

  12. A day in the CERN Control Centre

    CERN Multimedia

    Rosaria Marraffino

    2015-01-01

    The CERN Control Centre (CCC) is the nerve centre of the CERN beam systems. From this room, the experts prepare, monitor, adjust, and control the particle beams that circulate throughout the accelerator complex while ensuring that the services and the technical infrastructure work flawlessly. Buttons, screens, telephones, lights (but no sound): in the CCC, everything is ready to make it possible for the LHC to reach the unprecedented energies expected at Run 2.   Seen from above, the CERN Control Centre resembles the shape of a quadrupole magnet. The consoles are distributed in four circles, called “islands”, dedicated to the LHC, the SPS, the PS Complex and the Technical Infrastructure (TI) respectively. Spread between TI and LHC are the Cryogenics consoles. Being in the same room allows the 24h-manned islands to be constantly in touch with one another, thus ensuring the best performance of the machines. At the LHC island, operators are currently busy training the magnet...

  13. Enhancing person-centred communication in NICU

    DEFF Research Database (Denmark)

    Weis, Janne; Zoffmann, Vibeke; Egerod, Ingrid

    2015-01-01

    Aims of this article were (a) to explore how parents of premature infants experience guided family-centred care (GFCC), and (b) to compare how parents receiving GFCC versus standard care (SC) describe nurse-parent communication in the neonatal intensive care unit.......Aims of this article were (a) to explore how parents of premature infants experience guided family-centred care (GFCC), and (b) to compare how parents receiving GFCC versus standard care (SC) describe nurse-parent communication in the neonatal intensive care unit....

  14. Imperial College Reactor Centre annual report. 1984

    International Nuclear Information System (INIS)

    The following new equipment is noted; for atomic absorption spectrometry to supplement the neutron activation analysis, and an additional nuclear data analysis system to improve the quality and speed of the service to users of the Centre's facilities. Users include undergraduates from the University of London, outside bodies such as the British Musueum, as well as departments of Colleges of the University of London. The reactor lost only three days through failures or faults. Two replacement fuel elements were put into the reactor during the year. The report contains brief accounts of 34 research programmes at the Centre. (U.K.)

  15. A study on socio-demographic profile and feasibility of DOTS provider registered under RNTCP in Varanasi district Uttar Pradesh

    Directory of Open Access Journals (Sweden)

    Mohd. Afzalul Haque

    2014-03-01

    Full Text Available Introduction: Tuberculosis is a major chronic disorder affecting the larger population more than any other disease in the country. DOTS was introduced in India in 1993 as part of the Revised National Tuberculosis Programme (RNTCP following a review of India’s National Tuberculosis Programme (NTP a year earlier (1 .Patient satisfaction is an important parameter for assessing the quality of patient care services. There is need to assess the health care provider regarding the consumer satisfaction as often as possible, this paper summarizes our experience about role of DOTS provider in the management of TB patient in rural population of Varanasi districts Utter Pradesh. Objective: (1 To assess the perception of registered tuberculosis patients regarding DOTS provider for the treatment of tuberculosis. (2 To assess the accessibility, acceptability & availability of community DOTS provider. Design: A longitudinal study. Setting: Three microscopic centre of Cholapur Tuberculosis unit of Varanasi districts. Methods: Registered patients were interviewed twice: once in the beginning and another at the completion of the treatment or after the permanent discontinuation of the treatment. Patients were interviewed for their socio-demographic profiles, opinion about DOTS and its providers. Side effects experienced and action taken etc. Data was collected on a semi-structured, pre-tested questionnaire. DOTS providers were interviewed and treatment cards analyzed for any interruption of treatment and action taken. Data was collected from 1st June 2004 to 31th June 2005 till the completion of the regimen. Results: Majority of DOTS providers were young males (82.7% of 26 years to 40 years, while the representation of females was only 5 (17.3%. Almost more than 80% of the patients started their treatment within 1-10 days. For majority of cases (83% the distance of DOTS provider from patient’s house was within 1 km. Mean time spent to go to DOTS provider was 27

  16. An evaluation of the dot-ELISA procedure as a diagnostic test in an area with a high prevalence of human Toxocara canis infection

    Directory of Open Access Journals (Sweden)

    María V Bojanich

    2012-03-01

    Full Text Available The aim of this work was to evaluate a dot-enzyme-linked immunosorbent assay (dot-ELISA using excretory-secretory antigens from the larval stages of Toxocara canis for the diagnosis of toxocariasis. A secondary aim was to establish the optimal conditions for its use in an area with a high prevalence of human T. canis infection. The dot-ELISA test was standardised using different concentrations of the antigen fixed on nitrocellulose paper strips and increasing dilutions of the serum and conjugate. Both the dot-ELISA and standard ELISA methods were tested in parallel with the same batch of sera from controls and from individuals living in the problem area. The best results were obtained with 1.33 µg/mL of antigen, dilutions of 1/80 for the samples and controls and a dilution of 1/5,000 for the anti-human IgG-peroxidase conjugate. All steps of the procedure were performed at room temperature. The coincidence between ELISA and dot-ELISA was 85% and the kappa index was 0.72. The dot-ELISA test described here is rapid, easy to perform and does not require expensive equipment. Thus, this test is suitable for the serological diagnosis of human T. canis infection in field surveys and in the primary health care centres of endemic regions.

  17. Large quantum dots with small oscillator strength

    DEFF Research Database (Denmark)

    Stobbe, Søren; Schlereth, T.W.; Höfling, S.;

    2010-01-01

    We have measured the oscillator strength and quantum efficiency of excitons confined in large InGaAs quantum dots by recording the spontaneous emission decay rate while systematically varying the distance between the quantum dots and a semiconductor-air interface. The size of the quantum dots...... is measured by in-plane transmission electron microscopy and we find average in-plane diameters of 40 nm. We have calculated the oscillator strength of excitons of that size assuming a quantum-dot confinement given by a parabolic in-plane potential and a hard-wall vertical potential and predict a very large...... oscillator strength due to Coulomb effects. This is in stark contrast to the measured oscillator strength, which turns out to be so small that it can be described by excitons in the strong confinement regime. We attribute these findings to exciton localization in local potential minima arising from alloy...

  18. Ge Quantum Dot Infrared Imaging Camera Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna Innovations Incorporated proposes to develop a high performance Ge quantum dots-based infrared (IR) imaging camera on Si substrate. The high sensitivity, large...

  19. Spin current in double quantum dot

    Institute of Scientific and Technical Information of China (English)

    Zhao Hua; Zhang Guo-Feng; Yin Wen; Liang Jiu-Qing

    2004-01-01

    We have studied the dynamical behaviours of two electrons confined in a double quantum dot driven by rotating magnetic fields in terms of the theory of Lewis-Riesenfeld Hermitian invariants for the explicitly time-dependent Hamiltonian. The coherent spin oscillations in the dot provide a generation source for spin current. Exact solutions obtained allow us to investigate the dynamical properties of the spin localization for various initial localized states.

  20. Magnetic quantum dots and magnetic edge states

    International Nuclear Information System (INIS)

    Starting with defining the magnetic edge state in a magnetic quantum dot, which becomes quite popular nowadays conjunction with a possible candidate for a high density memory device or spintronic materials, various magnetic nano-quantum structures are reviewed in detail. We study the magnetic edge states of the two dimensional electron gas in strong perpendicular magnetic fields. We find that magnetic edge states are formed along the boundary of the magnetic dot, which is formed by a nonuniform distribution of magnetic fields. These magnetic edge states circulate either clockwise or counterclockwise, depending on the number of missing flux quanta, and exhibit quite different properties, as compared to the conventional ones which are induced by electrostatic confinements in the quantum Hall system. We also find that a close relation between the quantum mechanical eigenstates and the classical trajectories in the magnetic dot. When a magnetic dot is located inside a quantum wire, the edge-channel scattering mechanism by the magnetic quantum dot is very different from that by electrostatic dots. Here, the magnetic dot is formed by two different magnetic fields inside and outside the dot. We study the ballistic edge-channel transport and magnetic edge states in this situation. When the inner field is parallel to the outer one, the two-terminal conductance is quantized and shows the features of a transmission barrier and a resonator. On the other hand, when the inner field is reversed, the conductance is not quantized and all channels can be completely reflected in some energy ranges. The difference between the above two cases results from the distinct magnetic confinements. We also describe successfully the edge states of magnetic quantum rings and others in detail

  1. Coherent scattering in a small quantum dot

    International Nuclear Information System (INIS)

    Ballistic transport in an open small (100 nm) three-terminal quantum dot based on the high-mobility two-dimensional electron gas of the AlGaAs/GaAs heterojunction has been analyzed. It has been shown that the gate oscillations of resistance of such a dot arise due to the coherent scattering of electrons on its quasidiscrete levels being suppressed by a weak magnetic field

  2. Exploring Extragalactic Emission: The Hα Dot Survey

    Science.gov (United States)

    Rampalli, Rayna; Salzer, John Joseph

    2016-01-01

    The Hα Dot Survey was established as a result of finding point sources of strong line emission in the data obtained for the ALFALFA Hα Survey (Van Sistine et al. 2015). In the latter survey, broad-band R and narrow-band Hα filters were used to examine target galaxies from the ALFALFA blind HI survey (Giovanelli et al. 2005, Haynes et al. 2011). In the process of reducing the ALFALFA Hα Survey data the "Hα Dots" were discovered (Kellar et al. 2008, 2012). Using specialized image analysis tools, a large population of dots has already been detected in the more than 1500 ALFALFA Hα narrow-band images taken with the 0.9m WIYN and 2.1m KPNO telescopes. Follow-up spectra of over 200 Hα Dots discovered from the 0.9m images reveal that these objects are a mix of nearby low-luminosity star-forming galaxies, compact starbursts and Seyfert 2 galaxies at intermediate redshifts, and high-redshift QSOs. Here we present the first list of Hα Dots detected using 2.1m telescope data. The 2.1m images yield a sample of Dots that average almost two magnitudes fainter than those detected with the 0.9m. The current REU project is designed to characterize the set of Hα Dots detected in the deeper 2.1m telescope images, while the broad goals of the Hα Dot Survey include the desire to understand better the chemical evolution of galaxies over cosmic time. This project was supported in part by the NSF REU grant 1358980, by the Maria Mitchell Association (Nantucket, MA), and by the Massachusetts Space Grant Consortium.

  3. [The coordination of care in health centres].

    Science.gov (United States)

    Ribardière, Olivia

    2016-06-01

    Health centres are structurally designed to facilitate the coordination of care. However, evolutions in society have resulted in forms of consumption of health care which are not necessarily compatible with efficient care coordination. On a local level, teams are nevertheless organising and structuring themselves to offer the right form of care, to the right patient and at the right time. PMID:27338687

  4. Renovation of the CERN Computer Centre

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The Computer Centre at CERN is seen after half of the equipment is the large ground floor room has been removed. A large-scale spring-cleaning operation took place before renovation work for the new CERN Grid system began. Fifteen kilometres of cables that were no longer needed were removed from the cavity floor for recycling.

  5. The Australian Centre for Minesite Rehabilitation Research

    International Nuclear Information System (INIS)

    The Australian Centre for Minesite Rehabilitation Research (ACMRR) is a joint venture between the Australian mining industry through the Australian Mineral Industries Research Association Ltd. (AMIRA) and three of the organizations working most actively in this area in Australia: CSIRO Minesite Rehabilitation Research Program; University of Queensland Centre for Mined Land Rehabilitation; and Curtin University Mulga Research Centre. The ACMRR was established in July 1993 to provide a national framework to conduct Strategic Research into minesite rehabilitation. It is an industry led and funded initiative. The Goals of the Centre include: to conduct strategic research into minesite rehabilitation to provide sustainable environmental solutions which are acceptable to industry, government and the community; to be recognized as a center of excellence undertaking commissioned research on minesite rehabilitation in an independent and thorough manner; to provide scientific and technological foundations to facilitate industry and government in setting acceptable standards; to act as networking and communications focus; and to enhance education and training in minesite rehabilitation. Strategic Research Programs in: Water Systems--downstream surface and groundwater quality; Land--the long-term behavior and stability of constructed landforms; Ecosystems--the long-term sustainability of constructed landforms; Waste--the long-term treatment and disposal of waste products; will allow the ACMRR to achieve these goals through specific research projects in these areas, developed with industry sponsors. This paper will discuss their progress to date, research projects underway, and plans for the future

  6. Interorganisatorisk styring i Shared Service Centre

    DEFF Research Database (Denmark)

    Harritz, Daniel

    2011-01-01

    I den offentlige sektor er der en stigende udbredelse af Shared Service Centre (SSC). Men der er endnu meget lidt viden om de interorganisatoriske styringsproblemstillinger, der opstår når et SSC oprettes. I denne artikel præsenteres, ud fra et interorganisatorisk perspektiv, en styringsramme der...

  7. [The coordination of care in health centres].

    Science.gov (United States)

    Ribardière, Olivia

    2016-06-01

    Health centres are structurally designed to facilitate the coordination of care. However, evolutions in society have resulted in forms of consumption of health care which are not necessarily compatible with efficient care coordination. On a local level, teams are nevertheless organising and structuring themselves to offer the right form of care, to the right patient and at the right time.

  8. In the Field: The Canadian Ecology Centre.

    Science.gov (United States)

    Magee, Clare

    2000-01-01

    The Canadian Ecology Centre (Ontario) offers year-round residential and day programs in outdoor and environmental education for secondary students, field placement and internship opportunities for college students, and ecotourism programs, while providing employment and tax revenues to the local community. Dubbed consensus environmentalism, the…

  9. Centring the Subject in Order to Educate

    Science.gov (United States)

    Webster, R. Scott

    2007-01-01

    It is important for educators to recognise that the various calls to decentre the subject--or self--should not be interpreted as necessarily requiring the removal of the subject altogether. Through the individualism of the Enlightenment the self was centred. This highly individualistic notion of the sovereign self has now been decentred especially…

  10. The fragility of human-centred design

    NARCIS (Netherlands)

    Steen, M.G.D.

    2008-01-01

    In human-centred design (HCD), researchers and designers develop products in cooperation with the potential users of these products. They attempt to give users a voice or a role in their projects, with the intention of developing products that match users' needs and preferences. This approach is esp

  11. Student-Centred Learning: A Humanist Perspective

    Science.gov (United States)

    Tangney, Sue

    2014-01-01

    The notion of student-centred learning is often not defined; within the pedagogic literature it is generally associated with constructivism or principles associated with a constructivist environment such as building on prior knowledge, purposeful active learning and sense-making. An informal enquiry into conceptions of university staff prior to…

  12. The young centre of the Earth

    DEFF Research Database (Denmark)

    Uggerhøj, Ulrik Ingerslev; Mikkelsen, Rune E.; Faye, Jan

    2016-01-01

    We treat, as an illustrative example of gravitational time dilation in relativity, the observation that the centre of the Earth is younger than the surface by an appreciable amount. Richard Feynman first made this insightful point and presented an estimate of the size of the effect in a talk...

  13. Quantum-dot-in-perovskite solids

    KAUST Repository

    Ning, Zhijun

    2015-07-15

    © 2015 Macmillan Publishers Limited. All rights reserved. Heteroepitaxy - atomically aligned growth of a crystalline film atop a different crystalline substrate - is the basis of electrically driven lasers, multijunction solar cells, and blue-light-emitting diodes. Crystalline coherence is preserved even when atomic identity is modulated, a fact that is the critical enabler of quantum wells, wires, and dots. The interfacial quality achieved as a result of heteroepitaxial growth allows new combinations of materials with complementary properties, which enables the design and realization of functionalities that are not available in the single-phase constituents. Here we show that organohalide perovskites and preformed colloidal quantum dots, combined in the solution phase, produce epitaxially aligned \\'dots-in-a-matrix\\' crystals. Using transmission electron microscopy and electron diffraction, we reveal heterocrystals as large as about 60 nanometres and containing at least 20 mutually aligned dots that inherit the crystalline orientation of the perovskite matrix. The heterocrystals exhibit remarkable optoelectronic properties that are traceable to their atom-scale crystalline coherence: photoelectrons and holes generated in the larger-bandgap perovskites are transferred with 80% efficiency to become excitons in the quantum dot nanocrystals, which exploit the excellent photocarrier diffusion of perovskites to produce bright-light emission from infrared-bandgap quantum-tuned materials. By combining the electrical transport properties of the perovskite matrix with the high radiative efficiency of the quantum dots, we engineer a new platform to advance solution-processed infrared optoelectronics.

  14. Coherent transport through interacting quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Hiltscher, Bastian

    2012-10-05

    The present thesis is composed of four different works. All deal with coherent transport through interacting quantum dots, which are tunnel-coupled to external leads. There a two main motivations for the use of quantum dots. First, they are an ideal device to study the influence of strong Coulomb repulsion, and second, their discrete energy levels can easily be tuned by external gate electrodes to create different transport regimes. The expression of coherence includes a very wide range of physical correlations and, therefore, the four works are basically independent of each other. Before motivating and introducing the different works in more detail, we remark that in all works a diagrammatic real-time perturbation theory is used. The fermionic degrees of freedom of the leads are traced out and the elements of the resulting reduced density matrix can be treated explicitly by means of a generalized master equation. How this equation is solved, depends on the details of the problem under consideration. In the first of the four works adiabatic pumping through an Aharonov-Bohm interferometer with a quantum dot embedded in each of the two arms is studied. In adiabatic pumping transport is generated by varying two system parameters periodically in time. We consider the two dot levels to be these two pumping parameters. Since they are located in different arms of the interferometer, pumping is a quantum mechanical effect purely relying on coherent superpositions of the dot states. It is very challenging to identify a quantum pumping mechanism in experiments, because a capacitive coupling of the gate electrodes to the leads may yield an undesired AC bias voltage, which is rectified by a time dependent conductance. Therefore, distinguishing features of these two transport mechanisms are required. We find that the dependence on the magnetic field is the key feature. While the pumped charge is an odd function of the magnetic flux, the rectified current is even, at least in

  15. 2H2O incorporation into hepatic acetyl-CoA and de novo lipogenesis as measured by Krebs cycle-mediated 2H-enrichment of glutamate and glutamine.

    Science.gov (United States)

    Silva, Ana Maria; Martins, Fatima; Jones, John G; Carvalho, Rui

    2011-12-01

    Deuterated water is widely used for measuring de novo lipogenesis on the basis of quantifying lipid (2)H-enrichment relative to that of body water. However, incorporation of (2)H-enrichment from body water into newly synthesized lipid molecules is incomplete therefore the true lipid precursor enrichment differs from that of body water. We describe a novel measurement of de novo lipogenesis that is based on a true precursor-product analysis of hepatic acetyl-CoA and triglyceride methyl enrichments from deuterated water. After deuterated water administration to seven in situ and seven perfused livers, acetyl-CoA methyl enrichment was inferred from (2)H nuclear magnetic resonance analysis of hepatic glutamate/glutamine (Glx) enrichment and triglyceride methyl enrichment was directly determined by (2)H nuclear magnetic resonance of triglycerides. Acetyl-CoA (2) H-enrichment was 71% ± 1% that of body water for in situ livers and 53% ± 2% of perfusate water for perfused livers. From the ratio of triglyceride-methyl/acetyl-CoA enrichments, fractional de novo lipogenesis rates of 0.97% ± 0.09%/2 hr and 7.92% ± 1.47%/48 hr were obtained for perfused and in situ liver triglycerides, respectively. Our method reveals that acetyl-CoA enrichment is significantly less than body water both for in situ and perfused livers. Furthermore, the difference between acetyl-CoA and body water enrichments is sensitive to the experimental setting.

  16. Syntheses and Crystal Structures of Two New Compounds Containing Triarylamineand Benzoic Hydrazide Units [Zn(μ-O2CCH=CHCO2)(C3H4N2)(H2O)]n

    Institute of Scientific and Technical Information of China (English)

    邹武新; 于海涛; 郭辉; 孟继本

    2004-01-01

    Two new compounds containing triarylamine and benzoic hydrazide units, 4-[N,N-di(4-toyl)amino]benzaldehyde-N-(4-ethoxylphenyl)-formyl hydrazone 3a and 4-[N,N-di(4-toyl) amino]benzaldehyde-N-(2-ethoxylphenyl)-formyl hydrazone 3b, have been synthesized and their crystal structures (C30H29N3O2, Mr = 463.56) were interpreted by a combination technique of 1HNMR, IR, elemental analysis, mass spectra, UV-Vis spectra and X-ray crystallography, respec- tively. The crystal of 3a belongs to monoclinic, space group P21/n with a = 9.321(3) A, b = 11.046(4) A, c = 24.335(9) A, β=92.649(7)°, V = 2502.7(16) A3, Z = 4,μ =0.078 mm-1, Dc =1.230 g/cm3, F(000) = 984, the final R = 0.0590 and wR = 0.1316 for 4367observed reflections with I > 2σ(I). The crystal of 3b belongs to monoclinic, space group P21/c with a = 10.637(4) A, b = 24.138(10) A, c = 10.398(4) A, β= 104.913(8)°, V= 2579.8(17) A3, Z = 4,μ = 0.075 mm-1, Dc = 1.194 g/cm3, F(000) = 984, the final R =0.0631 and wR =0.1006 for 4463 observed reflections with I > 2σ(I). X-ray crystallography revealed that the nitrogen atom in the triarylamine moiety is of sp2 hybridization with the three phenyl rings twisted to each other.

  17. The Effect of O2, H2O, and N2 on the Fatigue Crack Growth Behavior of an Alpha + Beta Titanium Alloy at 24 C and 177 C

    Science.gov (United States)

    Smith, Stephen W.; Piascik, Robert S.

    2001-01-01

    To study the effects of atmospheric species on the fatigue crack growth behavior of an a+B titanium alloy (Ti 6-2-2-2-2) at room temperature and 177 C, fatigue tests were performed in laboratory air, ultrahigh vacuum, and high purity water vapor, oxygen, nitrogen and helium at various partial pressures. Accelerated fatigue crack growth rates in laboratory air compared to ultrahigh vacuum are linked to the damaging effects of both water vapor and oxygen. Observations of the fatigue crack growth behavior in ultrahigh purity environments, along with surface film analysis using X-ray photoelectron spectroscopy (XPS), suggest that multiple crack-tip processes govern the damaging effects of air. Three possible mechanisms are proposed: 1) at low pressure (less than 10(exp -1) Pa), accelerated da/dN is likely due to monolayer adsorption on crack-tip surfaces presumably resulting in decreased bond strengths at the fatigue crack tip, 2) for pressures greater than 10(exp -1) Pa, accelerated da/dN in oxygen may result from oxidation at the crack tip limiting reversible slip, and 3) in water vapor, absorption of atomic hydrogen at the reactive crack tip resulting in process zone embrittlement.

  18. Fasudil inhibits apoptosis of skeletal muscle satellite cells induced by H2O2%H2O2诱导骨骼肌卫星细胞凋亡及法舒地尔的保护作用

    Institute of Scientific and Technical Information of China (English)

    李江华; 董少红; 熊玮; 刘启云; 梁新剑; 庞新利

    2015-01-01

    BACKGROUND:Skeletal muscle satelite cels are muscle-derived stem cels with proliferation and differentiation potential distributing between the muscle cel membrane and the base film. Studies have shown that skeletal muscle satelite cels are of efficacy and safety, but the survival rate of the transplanted stem cels is very low, which greatly limits the application of skeletal muscle satelite cels. OBJECTIVE: To observe the effects of Fasudil on apoptosis of skeletal muscle satelite cels induced by H2O2. METHODS: Skeletal muscle satelite cels cultured in vitro were randomly divided into three groups including H2O2group, H2O2+Fasudil group (Fasudil group) and control group. Apoptosis rates were observed by flow cytometry. The concentrations of interleukin-4 and tumor necrosis factor-a in each group were detected by ELISA. Western blot was employed to measure the protein level of Bax in each group. RESULTS AND CONCLUSION: Compared with the H2O2group, a significant decrease was found in the apoptosis rate of cels, protein level of Bax, and concentrations of interleukin-4 and tumor necrosis factor-a in the Fasudil group (alP < 0.05). These findings indicate that Fasudil can play anti-apoptosis protection by inhibiting Rho-kinase signaling pathway, which may be related to the reduced expression of Bax.%背景:骨骼肌卫星细胞是成体骨骼肌中位于肌细胞膜和基膜之间具有增殖分化潜能的肌源性干细胞,研究表明骨骼肌卫星细胞的有效性及安全性,但是移植后的干细胞成活率极低,极大的限制了骨骼肌卫星细胞的应用.目的:观察过氧化氢(H2O2)对大鼠骨骼肌卫星细胞凋亡的影响以及法舒地尔的保护作用.方法:取体外培养的骨骼肌卫星细胞,随机分为正常对照组,H2O2组,H2O2+法舒地尔组(法舒地尔组),采用流式细胞仪检测细胞凋亡率,ELISA法检测白细胞介素4、肿瘤坏死因子a的浓度,Western blot检测Bax蛋白的表达.结果与结论:同H2O2组相比,法舒地尔组凋亡发生率明显下降(P< 0.05),Bax蛋白水平表达明显降低(P< 0.05),白细胞介素4、肿瘤坏死因子a的分泌显著减少(P< 0.05).结果提示,法舒地尔抑制Rho激酶信号途径发挥抗凋亡保护作用,其机制可能与减少Bax蛋白的表达有关.

  19. Rapid Thermolysis Studies of [Pb2(TNR)2(CHZ)2(H2O)2]·4H2O and Cd(CHZ)2(TNR)(H2O)

    Institute of Scientific and Technical Information of China (English)

    ZUO, Xiao-Li; QIAO, Xiao-Jing; SUN,Yuan-Hua; ZHANG, Tong-Lai; ZHANG, Jian-Guo; YANG, Li; WANG, Shao-Zong

    2007-01-01

    T-jump/FT-IR spectroscopy was used to study the rapid thermal decomposition activity of the major gaseous products of flash pyrolysis of Cd(CHZ)2(TNR)(H2O). Thus Cd(CHZ)2(TNR)(H2O) is not an eco-friendly and chemically compatible primary explosive. Both compounds liberate volatile metal carbonate, oxide and isocyanate compounds. The combustion temperature and products of the two compounds were calculated by Real code. The results of theoretical calculation show that the combustion temperature of tion products and the amount of NO is less than the experiment result from T-jump/FTIR.

  20. Kinetic double-layer model of aerosol surface chemistry and gas-particle interactions (K2-SURF: degradation of polycyclic aromatic hydrocarbons exposed to O3, NO2, H2O, OH and NO3

    Directory of Open Access Journals (Sweden)

    U. Pöschl

    2009-09-01

    Full Text Available We present a kinetic double-layer surface model (K2-SURF that describes the degradation of polycyclic aromatic hydrocarbons (PAHs on aerosol particles exposed to ozone, nitrogen dioxide, water vapor, hydroxyl and nitrate radicals. The model is based on multiple experimental studies of PAH degradation and on the PRA framework (Pöschl et al., 2007 for aerosol and cloud surface chemistry and gas-particle interactions. For a wide range of substrates, including solid and liquid organic and inorganic substances (soot, silica, sodium chloride, octanol/decanol, organic acids, etc., the concentration- and time-dependence of the heterogeneous reaction between PAHs and O3 can be efficiently described with a Langmuir-Hinshelwood-type mechanism. Depending on the substrate material, the Langmuir adsorption constants for O3 vary over three orders of magnitude (Kads,O3≈10−15–10−13 cm3, and the second-order rate coefficients for the surface layer reaction of O3 with different PAH vary over two orders of magnitude (kSLR,PAH,O3≈10−18–10−17 cm2 s−1. The available data indicate that the Langmuir adsorption constants for NO2 are similar to those of O3, while those of H2O are several orders of magnitude smaller (Kads,H2O≈10−18–10−17 cm3. The desorption lifetimes and adsorption enthalpies inferred from the Langmuir adsorption constants suggest chemisorption of NO2 and O3 – possibly in the form of O atoms – and physisorption of H2O. The K2-SURF model enables the calculation of ozone uptake coefficients, γO3, and of PAH concentrations in the quasi-static particle surface layer. Competitive adsorption and chemical transformation of the surface (aging lead to a strong non-linear dependence of γO3 on time and gas phase composition, with different characteristics under dilute atmospheric and concentrated laboratory conditions. Under typical ambient conditions, γO3 of PAH-coated aerosol particles are expected to be in the range of 10−6–10−5. At ambient temperatures, NO2 alone does not efficiently degrade PAHs, but it was found to accelerate the degradation of PAHs exposed to O3. The accelerating effect can be attributed to highly reactive NO3 radicals formed in the gas phase or on the surface. Estimated second-order rate coefficients for O3-NO2 and PAH-NO3 surface layer reactions are in the range of 10−17–10−16 cm2 s−1 and 10−15–10−12 cm2 s−1, respectively. The chemical half-life of PAH is expected to range from a few minutes on the surface of soot to multiple hours on organic and inorganic solid particles and days on liquid particles. On soot, the degradation of particle-bound PAHs in the atmosphere appears to be dominated by a surface layer reaction with adsorbed ozone. On other substrates, it is likely dominated by gas-surface reactions with OH or NO3 radicals (Eley-Rideal-type mechanism. To our knowledge, K2-SURF is the first atmospheric process model describing multiple types of parallel and sequential surface reactions between multiple gaseous and particle-bound chemical species. It illustrates how the general equations of the PRA framework can be simplified and adapted for specific reaction systems, and we suggest that it may serve as a basis for the development of a general master mechanism of aerosol and cloud surface chemistry.

  1. Synthesis and Crystal Structure of an Infinite 1D Zigzag Chain Compound (dimbH+)(ClO4-) and Its Comparison with (dimb)·2H2O (dimb =1,3-Di(imidazol-1-ylmethyl)-5-methylbenzene)

    Institute of Scientific and Technical Information of China (English)

    姚景才; 马勇林; 黄伟; 苟少华

    2003-01-01

    A new imidazolium compound, C15H17N4(ClO4, was prepared from a flexible bidentate ligand of 1,3-di(imidazol-1-ylmethyl)-5-methylbenzene, and characterized by X-ray analysis. It is of orthorhombic, space group Pnma with a = 8.182(2), b = 12.874(3), c = 15.611(4) (A。), V = 1644.4(7) (A。)3, Dc = 1.425 g/cm3, Z = 4, Mr = 352.78, μ(MoKα) = 0.944 mm-1, F(000) = 736, S = 1.036, the final R = 0.0521 and wR = 0.1187 for 1128 observed reflections (I > 2σ(I)). An infinite one-dimensional zigzag chain is formed by N-H…N hydrogen bonding interactions between the imidazolium salt cations.

  2. In Situ Raman Spectroscopic Study of Gypsum (CaSO4·2H2O) and Epsomite (MgSO4·7H2O) Dehydration Utilizing an Ultrasonic Levitator.

    Science.gov (United States)

    Brotton, Stephen J; Kaiser, Ralf I

    2013-02-21

    We present an original apparatus combining an acoustic levitator and a pressure-compatible process chamber. To characterize in situ the chemical and physical modifications of a levitated, single particle while heated to well-defined temperatures using a carbon dioxide laser, the chamber is interfaced to a Raman spectroscopic probe. As a proof-of-concept study, by gradually increasing the heating temperature, we observed the variations in the Raman spectra as 150 μg of crystals of gypsum and epsomite were dehydrated in anhydrous nitrogen gas. We display spectra showing the decreasing intensities of the ν1 symmetric and ν3 asymmetric stretching modes of water with time and the simultaneous shift of the ν1(SO4(2-)) symmetric stretch mode to higher wavenumbers. Our results demonstrate that the new apparatus is well suited to study the dehydration of levitated species such as minerals and offers potential advantages compared with previous experiments on bulk samples. PMID:26281883

  3. Synthesis and characterization of a chiral dimeric copper(II) complex: Crystal structure of [Cu2(-Cl)2(HL)2].H2O(H2L = -(-)-2-[(2-hydroxy-1-phenyl-ethylimino)-methyl]-phenol)

    Indian Academy of Sciences (India)

    Chullikkattil P Pradeep; Panthapally S Zacharias; Samar K Das

    2005-03-01

    Synthesis and characterization of an optically active binuclear dichloro-bridged copper(II) complex [Cu2(-Cl)2(HL)2]$\\cdot$H2O 1 (H2L = -(-)-2-[(2-hydroxy-1-phenyl-ethylimino)-methyl]-phenol) of a Schiff-base derived from salicylaldehyde and ()-(+)-2-phenylglycinol are described. Compound 1 crystallizes in the orthorhombic chiral P212121 space group with = 4, = 10.21(2), = 11.574(3), = 25.364(9). Each copper shows square pyramidal geometry with O2NCl2 coordination and the Cu2Cl2 core geometry adopts a butterfly shape. Crystals of 1 were further characterized by elemental analysis, IR, UV-visible and EPR spectroscopy and circular dichroism (CD) studies.

  4. OVERALL EQUILIBRIUM POTENTIAL-pH DIAGRAM FOR FeS2-H2O SYSTEM AND ITS APPLICTION%FeS2-H2O系综合平衡电势-pH图及其应用

    Institute of Scientific and Technical Information of China (English)

    易平贵; 刘俊峰; 金一粟

    1999-01-01

    根据综合平衡原理,建立和讨论了一种新型的FeS2-H2O系电势-pH图及该体系中溶液态物质的浓度分布函数.单质硫只有较小的稳定区且依赖于溶液中含硫物种总浓度Ct(S)和H2S气体的分压大小,当Ct(S)固定时,分压小于某临界值后单质硫的稳定区将消失.Fe2O3(S)和FeS2(S)的稳定区均很大,Fe2O3的稳定性与溶液中含铁总浓度Ct(Fe)有关,而FeS2的稳定性与Ct(S)、Ct(Fe)及H2S气体的分压均有关.图3,表3,参4.

  5. Aircraft measurements of BrO, IO, glyoxal, NO2, H2O, O2-O2 and aerosol extinction profiles in the tropics: comparison with aircraft-/ship-based in situ and lidar measurements

    Science.gov (United States)

    Volkamer, R.; Baidar, S.; Campos, T. L.; Coburn, S.; DiGangi, J. P.; Dix, B.; Eloranta, E. W.; Koenig, T. K.; Morley, B.; Ortega, I.; Pierce, B. R.; Reeves, M.; Sinreich, R.; Wang, S.; Zondlo, M. A.; Romashkin, P. A.

    2015-05-01

    Tropospheric chemistry of halogens and organic carbon over tropical oceans modifies ozone and atmospheric aerosols, yet atmospheric models remain largely untested for lack of vertically resolved measurements of bromine monoxide (BrO), iodine monoxide (IO) and small oxygenated hydrocarbons like glyoxal (CHOCHO) in the tropical troposphere. BrO, IO, glyoxal, nitrogen dioxide (NO2), water vapor (H2O) and O2-O2 collision complexes (O4) were measured by the University of Colorado Airborne Multi-AXis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument, aerosol extinction by high spectral resolution lidar (HSRL), in situ aerosol size distributions by an ultra high sensitivity aerosol spectrometer (UHSAS) and in situ H2O by vertical-cavity surface-emitting laser (VCSEL) hygrometer. Data are presented from two research flights (RF12, RF17) aboard the National Science Foundation/National Center for Atmospheric Research Gulfstream V aircraft over the tropical Eastern Pacific Ocean (tEPO) as part of the "Tropical Ocean tRoposphere Exchange of Reactive halogens and Oxygenated hydrocarbons" (TORERO) project (January/February 2012). We assess the accuracy of O4 slant column density (SCD) measurements in the presence and absence of aerosols. Our O4-inferred aerosol extinction profiles at 477 nm agree within 6% with HSRL in the boundary layer and closely resemble the renormalized profile shape of Mie calculations constrained by UHSAS at low (sub-Rayleigh) aerosol extinction in the free troposphere. CU AMAX-DOAS provides a flexible choice of geometry, which we exploit to minimize the SCD in the reference spectrum (SCDREF, maximize signal-to-noise ratio) and to test the robustness of BrO, IO and glyoxal differential SCDs. The RF12 case study was conducted in pristine marine and free tropospheric air. The RF17 case study was conducted above the NOAA RV Ka'imimoana (TORERO cruise, KA-12-01) and provides independent validation data from ship-based in situ cavity-enhanced DOAS and MAX-DOAS. Inside the marine boundary layer (MBL) no BrO was detected (smaller than 0.5 pptv), and 0.2-0.55 pptv IO and 32-36 pptv glyoxal were observed. The near-surface concentrations agree within 30% (IO) and 10% (glyoxal) between ship and aircraft. The BrO concentration strongly increased with altitude to 3.0 pptv at 14.5 km (RF12, 9.1 to 8.6° N; 101.2 to 97.4° W). At 14.5 km, 5-10 pptv NO2 agree with model predictions and demonstrate good control over separating tropospheric from stratospheric absorbers (NO2 and BrO). Our profile retrievals have 12-20 degrees of freedom (DoF) and up to 500 m vertical resolution. The tropospheric BrO vertical column density (VCD) was 1.5 x 1013 molec cm-2 (RF12) and at least 0.5 x 1013 molec cm-2 (RF17, 0-10 km, lower limit). Tropospheric IO VCDs correspond to 2.1 x 1012 molec cm-2 (RF12) and 2.5 x 1012 molec cm-2 (RF17) and glyoxal VCDs of 2.6 x 1014 molec cm-2 (RF12) and 2.7 x 1014 molec cm-2 (RF17). Surprisingly, essentially all BrO as well as the dominant IO and glyoxal VCD fraction was located above 2 km (IO: 58 ± 5%, 0.1-0.2 pptv; glyoxal: 52 ± 5%, 3-20 pptv). To our knowledge there are no previous vertically resolved measurements of BrO and glyoxal from aircraft in the tropical free troposphere. The atmospheric implications are briefly discussed. Future studies are necessary to better understand the sources and impacts of free tropospheric halogens and oxygenated hydrocarbons on tropospheric ozone, aerosols, mercury oxidation and the oxidation capacity of the atmosphere.

  6. Synthesis and Crystal Structure of a 3-D Hydrogen-bonded Supramolecular Decavanadate Compound [Habo]6[V10O28]·2C3H7OH·2H2O

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new inorganic-organic hybrid supramolecular compound [Habo]6[V10O28]·solvents and its crystal structure was reported as follows: monoclinic, space group P21/n, a =11.419(9), b = 16.811(16), c = 15.521(12) (A), β= 102.98(2)°, V= 2903(4) (A)3, Z = 4, C15H46N3O19V5,Mr = 827.25, Dc = 1.893 g/cm3, λ(MoKα) = 0.71073 A,μ = 1.636 mm-1, F(000) = 1696, the final R =0.0696 and wR = 0.1361 for 4641 observed reflections with I > 2σ(I). The compound is based on decavanadate clusters [V 1oO28]6-. The hydrogen bonding interactions among Habo+ cations, solvents and decavanadate clusters extend 1 into a three-dimensional supramolecular architecture.

  7. Untersuchungen zu den Phasengleichgewichten der Systeme (CO2 + MDEA + PIPH2 + H2O), (CH4 + organische Lösungsmittel) und das LW-H-V-Gleichgewicht des Systems (CH4 + H2O)

    OpenAIRE

    Böttger, Arne

    2009-01-01

    In der vorliegenden Arbeit werden experimentelle und theoretische Untersuchungen für die Löslichkeiten von Methan in den organischen Lösungsmitteln Petroleumbenzin, 1-Oktanol, n-Hexan und n-Dodekan sowie Untersuchungen des LW-H-V-Gleichgewichts des Systems (CH4 + H2O) vorgestellt. Im Vergleich zu den Vorhersageergebnissen von Sloan sowie Parrish und Praus-nitz wurde mit dem in der vorliegenden Arbeit weiterentwickelten, thermodynamischen Modell für das Hydratgleichgewicht des Systems (CH4 + H...

  8. Aircraft Measurements of BrO, IO, Glyoxal, NO2, H2O, O2-O2 and Aerosol Extinction Profiles in the Tropics: Comparison with Aircraft-/Ship-Based in Situ and Lidar Measurements

    Science.gov (United States)

    Volkamer, R.; Baidar, S.; Campos, T. L.; Coburn, S.; DiGangi, J. P.; Dix, B.; Eloranta, E. W.; Koenig, T. K.; Morley, B.; Ortega, I.; Pierce, B. R.; Reeves, M.; Sinreich, R.; Wang, S.; Zondlo, M. A.; Romashkin, P. A.

    2015-01-01

    Tropospheric chemistry of halogens and organic carbon over tropical oceans modifies ozone and atmospheric aerosols, yet atmospheric models remain largely untested for lack of vertically resolved measurements of bromine monoxide (BrO), iodine monoxide (IO) and small oxygenated hydrocarbons like glyoxal (CHOCHO) in the tropical troposphere. BrO, IO, glyoxal, nitrogen dioxide (NO2), water vapor (H2O) and O2-O2 collision complexes (O4/ were measured by the University of Colorado Airborne Multi-AXis Differential Optical Absorption Spectroscopy (CU AMAXDOAS) instrument, aerosol extinction by high spectral resolution lidar (HSRL), in situ aerosol size distributions by an ultra high sensitivity aerosol spectrometer (UHSAS) and in situ H2O by vertical-cavity surface-emitting laser (VCSEL) hygrometer. Data are presented from two research flights (RF12, RF17) aboard the National Science Foundation/ National Center for Atmospheric Research Gulfstream V aircraft over the tropical Eastern Pacific Ocean (tEPO) as part of the "Tropical Ocean tRoposphere Exchange of Reactive halogens and Oxygenated hydrocarbons" (TORERO) project (January/February 2012). We assess the accuracy of O4 slant column density (SCD) measurements in the presence and absence of aerosols. Our O4-inferred aerosol extinction profiles at 477 nm agree within 6% with HSRL in the boundary layer and closely resemble the renormalized profile shape of Mie calculations constrained by UHSAS at low (sub-Rayleigh) aerosol extinction in the free troposphere. CU AMAX-DOAS provides a flexible choice of geometry, which we exploit to minimize the SCD in the reference spectrum (SCDREF, maximize signal-to-noise ratio) and to test the robustness of BrO, IO and glyoxal differential SCDs. The RF12 case study was conducted in pristine marine and free tropospheric air. The RF17 case study was conducted above the NOAA RV Ka'imimoana (TORERO cruise, KA-12-01) and provides independent validation data from ship-based in situ cavity-enhanced DOAS and MAX-DOAS. Inside the marine boundary layer (MBL) no BrO was detected (smaller than 0.5 pptv), and 0.2-0.55 pptv IO and 32-36 pptv glyoxal were observed. The near-surface concentrations agree within 30% (IO) and 10% (glyoxal) between ship and air-craft. The BrO concentration strongly increased with altitude to 3.0 pptv at 14.5 km (RF12, 9.1 to 8.6 deg N; 101.2 to 97.4 deg W). At 14.5 km, 5-10 pptv NO2 agree with model predictions and demonstrate good control over separating tropospheric from stratospheric absorbers (NO2 and BrO). Our profile retrievals have 12-20 degrees of freedom (DoF) and up to 500m vertical resolution. The tropospheric BrO vertical column density (VCD) was 1.5 x 10(exp 13) molec cm(exp -2) (RF12) and at least 0.5 x 10(exp 13) molec cm(exp -2) (RF17, 0- 10 km, lower limit). Tropospheric IO VCDs correspond to 2.1 x 10(exp 12) molec cm(exp -2) (RF12) and 2.5 x 10(exp 12) molec cm(exp -2) (RF17) and glyoxal VCDs of 2.6 x 10(exp 14) molec cm(exp -2) (RF12) and 2.7 x 10(exp 14) molec cm(exp -2) (RF17). Surprisingly, essentially all BrO as well as the dominant IO and glyoxal VCD fraction was located above 2 km (IO: 58 plus or minus 5 %, 0.1-0.2 pptv; glyoxal: 52 plus or minus 5 %, 3-20 pptv). To our knowledge there are no previous vertically resolved measurements of BrO and glyoxal from aircraft in the tropical free troposphere. The atmospheric implications are briefly discussed. Future studies are necessary to better understand the sources and impacts of free tropospheric halogens and oxygenated hydrocarbons on tropospheric ozone, aerosols, mercury oxidation and the oxidation capacity of the atmosphere.

  9. Infrared matrix isolation studies of hydrogen bonds involving C-H bonds: CF 3H, (CF 2H) 2O and CF 3OCF 2H with selected bases

    Science.gov (United States)

    Jeng, Mei-Lee H.; Ault, Bruce S.

    1991-06-01

    Hydrogen bonded complexes of fluoroform and fluoromethylethers with halide anions and amines have been isolated at 15 K in argon matrices and characterized by IR spectroscopy. The observed red shifts of the CH stretching mode were significantly less than for analogous alkyne complexes. For a given alkane, the magnitude of shifts for complexes with the halide anions were greater than complexes with neutral amines, consistent with the greater basicity of the halide anions. The perturbed and shifted CH bending mode and its overtone were also observed, as well as perturbations to the CF stretching and bending modes. The spectral evidence tentatively suggests a monodentate hydrogen bond for the (CF 2H) 2O•F - complex, rather than the bidentate structure inferred from ion cyclotron resonance data.

  10. In-situ purification of aligned carbon nanotube arrays by H2O2%H2O2原位净化定向碳纳米管阵列的研究

    Institute of Scientific and Technical Information of China (English)

    王野; 拜晓东; 梁吉

    2005-01-01

    采用无模板的化学气相沉积法(CVD),在石英衬底上制备了大面积、高定向性、自支撑的定向碳纳米管阵列.对此阵列采用原位H2O2氧化,可以有效地达到净化定向碳纳米管阵列的目的.扫描电镜(SEM)检测表明净化碳纳米管的过程并不会破坏其定向性.此种方法可以获得不同厚度的、多数碳管端帽打开、非晶碳、缺陷碳管和杂质较少的定向碳纳米管阵列,此种阵列在场发射等方面具有应用价值.Raman光谱和热失重分析(TGA)表明经过净化的碳纳米管的晶化程度和热稳定性都有所提高.

  11. Treatment Outcomes of Patients Placed on Treatment Under Directly Observed Therapy Short-Course (Dots)

    Science.gov (United States)

    Kaur, Gurpreet; Goel, N.K.; Kumar, Dinesh; Janmeja, A.K.; Swami, H.M.; Kalia, Meenu

    2008-01-01

    Background: Tuberculosis continues to be a pressing health problem in India. The Revised National Tuberculosis Programme (RNTCP), an application of Directly Observed Treatment Short-course (DOTS) in India, launched in 1997 needs continuous evaluation. Objective: To study the outcomes of treatment among the patients put on DOTS under RNTCP in Chandigarh, UT. Material & Methods: A Longitudinal study was conducted during 2004-2005 in 13 Microscopic centres (MC's) spread over 2 Tuberculosis Units (TU's) under District Tuberculosis Centre (DTC) in Union Territory (UT), Chandigarh. A sample of 265 respondents, selected by two-stage stratified random sampling technique, was recruited in the study cohort. Data analysis was done using SPSS-10 statistical software package. Results: For Category I and Category II patients, the Success rate was 98.6% and 90.4% respectively. The overall default rate was 1.1% and failure rate was 2.6%. For re-treatment cases, failure rate was higher i.e. 5.8%. The sputum conversion rate among the new smear positive cases was 93.8% at 3 months of treatment. For the re-treatment cases, spu-tum conversion rate at 3 months was 94.1%. Conclusion: The study concludes that RNTCP is running successfully in UT Chandigarh, having high success rate and low default rate. The reasons for high failure rate should be explored in depth. PMID:20165654

  12. Treatment outcomes of patients placed on treatment under directly observed therapy short-course (DOTS

    Directory of Open Access Journals (Sweden)

    Kaur Gurpreet

    2008-01-01

    Full Text Available Background : Tuberculosis continues to be a pressing health problem in India. The Revised National Tuberculosis Programme (RNTCP, an application of Directly Observed Treatment Short-course (DOTS in India, launched in 1997 needs contin-uous evaluation. Objective : To study the outcomes of treatment among the patients put on DOTS under RNTCP in Chandigarh, UT. Material & Methods : A Longitudi-nal study was conducted during 2004-2005 in 13 Microscopic centres (MC′s spread over 2 Tuberculosis Units (TU′s under District Tuberculosis Centre (DTC in Union Territory (UT, Chandigarh. A sample of 265 respondents, selected by two-stage stratified random sampling technique, was recruited in the study cohort. Data analysis was done using SPSS-10 statistical software package. Results : For Category I and Category II patients, the Success rate was 98.6% and 90.4% respectively. The overall default rate was 1.1% and failure rate was 2.6%. For re-treatment cases, failure rate was higher i.e. 5.8%. The sputum conversion rate among the new smear positive cases was 93.8% at 3 months of treatment. For the re-treatment cases, spu-tum conversion rate at 3 months was 94.1%. Conclusion : The study concludes that RNTCP is running successfully in UT Chandigarh, having high success rate and low default rate. The reasons for high failure rate should be explored in depth.

  13. Dot-dye-immunoassay for the diagnosis of schistosomiasis mansoni

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Teles Rabello

    1992-06-01

    Full Text Available A new serological assay dot-dye-immunoassay (dot-DIA was evaluated for the diagnosis of schistosomiasis mansoni. This method consist of four steps: (a biding of antigens to a nitrocellulose membrane (NC; (b blocking of free sites of the NC; (c incubation in specific primary antibody; (d detection of primary antibody reactivity by color development using second antibody coupled to textile dyes. Sera from 82 individuals, 61 with Schistosoma mansoni eggs in the stool and 21 stool negative were tested by ELISA, dot-ELISA, and dotDIA. A high level of agreement between the methods tested was observed for all sera tested: ELISA x dot-ELISA: 95.1%, ELISA x dot-DIA: 92.7% and dot-ELISA x dot-DIA: 97.6%. In this study, dot-DIA proved to be a feasible, sensitive, rapid and practical test for the diagnosis of shcistosomiasis.

  14. Person-centred care in nursing documentation.

    LENUS (Irish Health Repository)

    Broderick, Margaret C

    2012-12-07

    BACKGROUND: Documentation is an essential part of nursing. It provides evidence that care has been carried out and contains important information to enhance the quality and continuity of care. Person-centred care (PCC) is an approach to care that is underpinned by mutual respect and the development of a therapeutic relationship between the patient and nurse. It is a core principle in standards for residential care settings for older people and is beneficial for both patients and staff (International Practice Development in Nursing and Healthcare, Chichester, Blackwell, 2008 and The Implementation of a Model of Person-Centred Practice in Older Person Settings, Dublin, Health Service Executive, 2010a). However, the literature suggests a lack of person-centredness within nursing documentation (International Journal of Older People Nursing 2, 2007, 263 and The Implementation of a Model of Person-Centred Practice in Older Person Settings, Dublin, Health Service Executive, 2010a). AIMS AND OBJECTIVES: To explore nursing documentation in long-term care, to determine whether it reflected a person-centred approach to care and to describe aspects of PCC as they appeared in nursing records. METHOD: A qualitative descriptive study using the PCN framework (Person-centred Nursing; Theory and Practice, Oxford, Wiley-Blackwell, 2010) as the context through which nursing assessments and care plans were explored. RESULTS: Findings indicated that many nursing records were incomplete, and information regarding psychosocial aspects of care was infrequent. There was evidence that nurses engaged with residents and worked with their beliefs and values. However, nursing documentation was not completed in consultation with the patient, and there was little to suggest that patients were involved in decisions relating to their care. IMPLICATIONS FOR PRACTICE: The structure of nursing documentation can be a major obstacle to the recording of PCC and appropriate care planning. Documentation

  15. Nuclear Electric Visitor Centres - Innovation and inspiration

    International Nuclear Information System (INIS)

    Full text: This eight minute video demonstrates the approach taken by Nuclear Electric to exhibitions that are open to the public. The information is given both visually - with excerpts from some of the attractions on display at the centres - and in comments from interviews with visitors, the centre guides and the man responsible for many of the exhibits featured in the video. on one side are the schoolchildren who are visiting the exhibition and are seen both playing and learning as they press buttons, watch videos, 'meet' Michael Faraday, and learn about radiation - its disposal and its safe transportation. The headmaster of the school is interviewed and explains that the exhibition is helping his children understand the importance of electricity to their world. on the other side is Jackie Lucas, the visitor centre manager, explaining what the public make of the exhibition. We see her staff greeting the children and helping them to understand the show. The designer of the exhibition, Len Upton explains how you go about making an exhibition such as this both informative and fun. Also interviewed is the man behind many of the exhibitions featured at Nuclear Electric's visitor centres up and down the country, Nicholas Mullane. He explains the purpose of the exhibition and what messages it imparts. The video is presented in split-screen or composite format, whereby the interviewee and children are often presented together. Excerpts from the various videos on display are presented as both how they are seen from the floor, as well as the full screen effect of the various programmes. The video gives much of the feeling of fun to be gained at the exhibition, as well as showing the educational benefits to be gained from a couple of hours at one of Nuclear Electric's visitor centres. Copies of the video can be obtained from Bob Fenton at Nuclear Electric. (Fax: ++44 1 452 652 443). (author)

  16. A new structure to increase the photostability of CdTe quantum dot sensitized solar cells

    International Nuclear Information System (INIS)

    In this paper a new cell structure is introduced to reduce the rate of CdTe corrosion in quantum dot sensitized solar cells (QDSSCs) using I-/I3- electrolyte. In this cell, one electrode is a titania nanorod that was sensitized with CdTe quantum dots as the working electrode. A thin gold layer is sputtered on the electrode to act as a protective layer against the I-/I3- corrosive electrolyte and to passivate the CdTe surface traps which are the main recombination centres in a QDSSC. In addition, a Schottky barrier formed at the interface of Au and CdTe prevents direct electron recombination from the CdTe conduction band with I3- ions. The mechanism of charge transfer and quantum dot regeneration in the presence of gold layer is discussed and our results show that the solar cells made of TiO2/CdTe/Au photoanode have more photostability and a higher fill factor relative to the TiO2/CdTe photoanodes.

  17. Realistic model of a vertical pillar quantum dot: Analysis of individual dot data

    NARCIS (Netherlands)

    Maksym, P.A.; Nishi, Y.; Austing, D.G.; Hatano, T.; Kouwenhoven, L.P.; Aoki, H.; Tarucha, S.

    2009-01-01

    An accurate model of a vertical pillar quantum dot is described. The full three-dimensional structure of the device containing the dot is taken into account and this leads to an effective two-dimensional model in which electrons move in the two lateral dimensions, the confinement is parabolic, and t

  18. Submonolayer Quantum Dot Infrared Photodetector

    Science.gov (United States)

    Ting, David Z.; Bandara, Sumith V.; Gunapala, Sarath D.; Chang, Yia-Chang

    2010-01-01

    A method has been developed for inserting submonolayer (SML) quantum dots (QDs) or SML QD stacks, instead of conventional Stranski-Krastanov (S-K) QDs, into the active region of intersubband photodetectors. A typical configuration would be InAs SML QDs embedded in thin layers of GaAs, surrounded by AlGaAs barriers. Here, the GaAs and the AlGaAs have nearly the same lattice constant, while InAs has a larger lattice constant. In QD infrared photodetector, the important quantization directions are in the plane perpendicular to the normal incidence radiation. In-plane quantization is what enables the absorption of normal incidence radiation. The height of the S-K QD controls the positions of the quantized energy levels, but is not critically important to the desired normal incidence absorption properties. The SML QD or SML QD stack configurations give more control of the structure grown, retains normal incidence absorption properties, and decreases the strain build-up to allow thicker active layers for higher quantum efficiency.

  19. Measurement of Eccentricity of the Centre of Mass from the Geometric Centre of a Sphere

    Institute of Scientific and Technical Information of China (English)

    郭俊起; 胡忠坤; 顾邦明; 罗俊

    2004-01-01

    The eccentricity of the centre of mass from the geometric centre of a spherical attracting mass in determining the Newtonian gravitational constant G is tested by means of an electronic balance. The experimental result shows that the eccentricity of the sample is about 0.31 μm with uncertainty of 0.05 μm. Two density distribution models are discussed to estimate the uncertainty to G by the eccentricities of the attracting masses.

  20. Understanding electronic systems in semiconductor quantum dots

    Science.gov (United States)

    Ciftja, Orion

    2013-11-01

    Systems of confined electrons are found everywhere in nature in the form of atoms where the orbiting electrons are confined by the Coulomb attraction of the nucleus. Advancement of nanotechnology has, however, provided us with an alternative way to confine electrons by using artificial confining potentials. A typical structure of this nature is the quantum dot, a nanoscale system which consists of few confined electrons. There are many types of quantum dots ranging from self-assembled to miniaturized semiconductor quantum dots. In this work we are interested in electrostatically confined semiconductor quantum dot systems where the electrostatic confining potential that traps the electrons is generated by external electrodes, doping, strain or other factors. A large number of semiconductor quantum dots of this type are fabricated by applying lithographically patterned gate electrodes or by etching on two-dimensional electron gases in semiconductor heterostructures. Because of this, the whole structure can be treated as a confined two-dimensional electron system. Quantum confinement profoundly affects the way in which electrons interact with each other, and external parameters such as a magnetic field. Since a magnetic field affects both the orbital and the spin motion of the electrons, the interplay between quantum confinement, electron-electron correlation effects and the magnetic field gives rise to very interesting physical phenomena. Thus, confined systems of electrons in a semiconductor quantum dot represent a unique opportunity to study fundamental quantum theories in a controllable atomic-like setup. In this work, we describe some common theoretical models which are used to study confined systems of electrons in a two-dimensional semiconductor quantum dot. The main emphasis of the work is to draw attention to important physical phenomena that arise in confined two-dimensional electron systems under various quantum regimes.