bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal Structure of 3Ni(N03)2
.16C6 H5NH2
Authors: Mahr Michael , Pabst Inge , Weil Konrad G. 
Published: February 2015

Abstract
The Compound 3Ni(NO3)2 -16C6H5NH2 was obtained by crystallization from solutions of Ni(NO3)2 • 6C6H5NH2 -2H2O in aniline. Its crystal structure was determined by single crystal X-ray diffraction. The crystals are triclinic, space group P1 with lattice constants a = 985.2 pm, ft = 1004.5 pm and c = 2514.3 pm, a = 96.34°, ß = 92.63° and y = 89.82°. The structure shows units of four aniline molecules and two slightly distorted nitrate ions in the coordination sphere of each nickel ion. These units are similar to contact ion pairs in concentrated ionic solutions.
The Transfer Matrix Grid Method for Quantum Partition Functions, Eigenvalues and Eigenfunctions
Authors: Prates Ramalho J. P. , Fernandes F. M. Silva 
Published: February 2015

Abstract
A method for the calculation of quantum partition functions, and bound eigenvalues and eigen-functions of the Hamiltonian operator is presented. The method is based on the discretization of the transfer matrix that relates the Feynman path integral to the conventional operator formulation of quantum mechanics. Its implementation is very simple, only requiring the diagonalization of the discretized transfer matrix. The method is applied to the harmonic oscillator and Morse potential. The results are in excellent agreement with the exact ones.
Ferroelektrische Cholesterin-Derivate
Authors: Vill V. , Thiem J. 
Published: February 2015

Abstract
The feature of liquid crystalline phases of p-alkoxybenzoyloxycholesterins was elucidated. In addition to blue, cholesteric and smectic A phases also monotropic, ferroelectric smectic C phases were detected. p-Alkoxybenzoic anhydrides obtained as side products in esterification reactions show highly ordered smectic phases which resemble those of the isosteric propanediones.
Molecular Motions and Phase Transitions in Solid CH3NH3PbX3 (X = C1, Br, I) as Studied by NMR and NQR
Authors: Xu Qiang , Eguchi Taro , Nakayama Hirokazu , Nakamura Nobuo , Kishita Michihiko 
Published: February 2015

Abstract
The temperature dependence of 35C1, 81Br, and 127I NQR frequencies and 1Hspin-lattice relaxation times (T1) for CH3NH3PbX3 (X = Cl, Br, I) was measured through the successive phase transitions in these solids. The isotropic reorientation of the CH3NH3 ions takes place in the higher-temperature phases (tetragonal [I4/mcm] and cubic) of the three salts (Ea= 11 kJ mol -1). T1's in the lowest-temperature phases (orthorhombic) indicate that the cations undergo correlated C3-reorientation in the chloride (Ea = 5.45 kJ mol -1)and in the iodide (Ea = 5.80 kJ mol -1, whereas correlated (Ea = 2.40 kJ mol-1) and uncorrected (Ea = 7.50 kJ mol-1) C3- reorientations are excited in the bromide. It is also revealed that the rotational tunneling of the cations governs T1 at lowtemperature region in the orthorhombic phases of these salts
Anisotropie Rotation of Yt-Base in n-Propanol at – 20°C Studied by Frequency-Domain Fluorometry and Global Analysis
Authors: Gryczynski Ignacy , Paszyc S. , Wiczk Wieslaw M. , Laczko Gabor , Joshi, Nanda , Szmacinski Henryk , Cherek Henryk 
Published: February 2015

Abstract
The frequency response of the polarized emission of Yt-base in n-propanol at -20°C was measured. Excitation wavelengths of 346, 312 and 285 nm were used for which the fundamental anisotropics were 0.32, 0.19 and 0.04, respectively. Additional data were obtained using CCl4 to decrease the mean decay time from 10 ns to 0.7 ns. These nine sets of data were analyzed globally to recover the anisotropy decay law. Two correlation times, of about 146 ps and 502 ps, were needed for a good fit
Notizen: The Preparation and Purification of Perhydrocoronene for Use as a Spectroscopic Matrix
Authors: Fetzer John C. , Biggs W. R. , Zander Maximilian 
Published: February 2015

Abstract
Perhydrocoronene has recently been studied as a matrix in low and high temperature luminescence spectroscopy of aromatic compounds. Perhydrocoronene has been found to be a by-product formed during the catalytic hydrocracking of a petroleum feedstock. The isolation and purification of spectroscopy grade perhydrocoronene is described in detail
Unbounded Perturbations of Boson Equilibrium States in Fock Space
Authors: Honegger Reinhard 
Published: February 2015

Abstract
Based on the linear coupling term in the non-relativistic quantum theory of matter-photon interactions, the coupling of a finite dimensional quantum system (finitely many finite-level atoms) with the boson gas (radiation field) in thermal equilibrium by means of perturbation theoretical methods is calculated. For the perturbation term of the Dyson expansion the unbounded interaction operator is taken. By a detailed analysis of the perturbation integrals and series, it is possible to derive the trace-class property of e-ßH , where H is the corresponding hamiltonian of the interacting systems and ß the inverse temperature
Steady-State and Flash Photolysis Investigations of 1 H-Indene-l,3(2H)-Dione Derivatives
Authors: Quint R. , Grabner G. , Quint R. M. , Getoff N. , Minchev St. 
Published: February 2015

Abstract
Pyrophthalone (PP, 2-(2-pyridinyl)-l H-indene-l,3(2H)-dione) and quinophthalone (QP, 2-(2-quinolinyl)- l H-indene-1,3(2 H)-dione) were investigated in various solvents with respect to their photostability. It was found that PP and QP in ethanol as well as QP in cyclohexane are rather stable under steady-state conditions using UV light (λ = 253.7 nm). Conventional as well as laser flash photolysis of airfree aqueous alkaline solutions (pH 12) lead to the formation of different radicals and solvated electrons (eaq). Some reaction rates were determined and probable reaction mechanisms were postulated
A Simple Rule regarding the Chemical Reactivity of S. T Isomer Pairs of kata-annellated Bejizenoid Hydrocarbons
Authors: Zander M. 
Published: February 2015

Abstract
For S, T isomer pairs of kata-annellated benzenoid hydrocarbons the inequality NS
min > NT
min holds, where NS
min and NT
min denote the lowest PMO localization energy of the S and T isomer, respectively. This empirical rule indicates that for a given S, T pair normally the S isomer will be the less reactive one
On the Spectra of Turbulent Velocity Field in a Stably Stratified Flow
Authors: Chakraborty A. K. , Vembe B. E. , Mazumdar H. P. 
Published: February 2015

Abstract
This paper describes a method to solve the spectral equation for the balance of turbulent kinetic energy in a stably stratified turbulent shear flow. The cospectra of vertical momentum and heat flux arc modelled with the aid of a basic eddy-viscosity (or turbulent exchange coefficient) function. For the term representing the inertial transfer of turbulent kinetic energy, Pao's [Phys. Fluids 8 (1965)] form is assumed. Analytical expressions for the three-dimensional kinetic energy spectrum as well as the cospectra of momentum and heat flux are obtained over the range of wave numbers k≥kb, which includes the inertial subrange kb≪k≪ks and the viscous subrange k>ks (kb and ks are the buoyancy and Kolmogorov wavenumbers, respectively). The two one-dimensional spectra, e.g., the kinetic energy spectra of the horizontal and vertical components of turbulence are derived from the three-dimensional kinetic energy spectrum. These one-dimensional spectra are compared with the measured data of Gargett et al. [J. Fluid Mech. 144 (1984)] for the case I ( = ks/kb) = 630. Finally, we compute the basic eddy-viscosity function and discuss its behavio
Viscosity Coefficients of a Nematic Mixture: Statistical Theory Approach
Authors: Terentjev E. M. , Osipov M. A. 
Published: February 2015

Abstract
A statistical theory of the rotational diffusion of a molecule in a two-component anisotropic mixture is developed, based on the Fokker-Planck approximation for the one-particle orientational distribution function. The friction constant of the molecular rotation is determined from the threeparticle correlation function, which takes into account interactions A-A, A-B, B-A and B-B between two sorts of molecules. The Leslie coefficients obtained possess a complicated dependence on mixture concentration together with a dependence on temperature and the molecular parameters of the components. In particular, the rotational viscosity coefficient γj is proportional to a polynomial of third-order in concentrations cA and cB with coefficients proportional to exp{JAca + JBcB} √(JACA + JB bcB )
Neutron and X-ray Scattering on Liquid Eutectic Ge-Te, Sn-Te and Pb-Te Alloys
Authors: Neumann Hartmut , Hoyer Walter , Wobst Manfred 
Published: February 2015

Abstract
From neutron and X-ray diffraction investigations on liquid Ge15Te85, Sn16Te84 and Pb14.5Te85.5 alloys the coordination numbers and nearest neighbour distances of these systems are obtained. The partial structure factors and partial pair correlations reveal that the short-range order of the eutectic Ge -Te melt differs from that of the eutectic Sn-Te and Pb-Te melts
Rotational Spectrum of Aminoborane: Centrifugal Distortion Constants and Boron and Nitrogen Hyperfine Structure
Authors: Vormann Kirsten , Dreizler Helmut , Doose Jens , Guarnieri Antonio 
Published: February 2015

Abstract
The boron and nitrogen hyperfine structure in the rotational spectra of two aminoborane isotopomers, 11 BH2NH2 and 10BH2NH2, has been investigated and the quadrupole coupling constants of boron 10B, 11B and nitrogen 14N have been determined. We get the following results for the nuclear quadrupole coupling constants: χaa(11B) = -1.684 (14) MHz, χbb(11B) = -2.212 (11) MHz, χcc(11B) = 3.896(11) MHz, χaa(10B) = -3.481 (11) MHz, χbb(10B) = -4.623 (14) MHz, χCC(10B) = 8.104 (14) MHz and xaa(14N) = 0.095 (9) MHz, χbb(14N) = 2.091 (8) MHz, χcf4 (14N)=-2.186 (8) MHz. These nitrogen quadrupole coupling constants are those of the 11BH2 NH2 isotopomer. Additionally we were able to determine two out of the three spin rotation coupling constants caa, cbb, and ccc of boron, caa(11 B = 55.2 (26) kHz, cbb(11B) = 6.62 (36) kHz, caa (10B) = 15.26 (69) kHz and cbb(10B) = 4.94 (70) kHz. The spin rotation coupling constants ccc had to be fixed to zero in both cases. Furthermore we measured the rotational spectra in the mm-wave region to determine all quartic and several sextic centrifugal distortion constants according to Watson's A and S reduction
Tetraalkylammonium Tetrachlorothallates (III); X-Ray, 35Cl-NQR, and 1H-NMR Studies
Authors: Lenck Marco , Dou Shi-qi , Weiss Alarich 
Published: February 2015

Abstract
The crystal structure of (CH3)4NTlCl4 and (C2H5)4NTlCl4 was determined at room temperature by single crystal technique. (CH3)4NTlCl4: D2h
17-Cmmm; Z = 2; a = 913.2pm, b = 894.6 pm, c = 752.5 pm; (C2H5)4NTlCl4: C6v
4-P63mc; Z = 2; a = 827.9 pm, c = 1329.8 pm. (C2H5)4NTlCl4 is isomorphous with (C2H5)4NInCl4. The compounds undergoe a phase transition at 239 K and 222 K, respectively. For both compounds no35 Cl NQR signal was observable in the high temperature phase I due to the dynamics of the anion. The 35 Cl NQR was studied in the low temperature phase II of both compounds as a function of temperature. (CH3)4NTlCl4 shows a two line, (C2H5)4NTlCl4 a four line spectrum. The possible phase II structures and the dynamics of the cation, studied by 1H-NMR, are discussed
Absorptions- and Electronic Raman Spectra of Chloro- Bromo-Osmate (IV), [OsClnBr6-nJ 2-, n=0-6
Authors: Irmer K. , Preetz W. 
Published: February 2015

Abstract
The electronic absorption spectra of the solid tetrabutylammonium salts of [OsClnBr6-n ]2-, n = 0-6, including the stereoisomers for n = 2, 3, 4, are measured at 10 K. The weak intraconfigurational excitations within the t2g
4, manifold of Os(lV) are split by spin orbit coupling and lowered symmetry into multiplets, observed in the NIR regions 2600-3100, 4800-5400, 10 500-11 400 and 16 000 17 200 cm-1. The 0-0-transitions are deduced from vibrational fine structure and they are confirmed by electronic Raman bands with the same frequencies
Unusual Temperature Dependence of 35Cl NQR Spin-Lattice Relaxation Time in [(CH3)4N]2[MCl6] (M = Pb, Sn, Te)
Authors: Furukawa Yoshihiro , Baba Yoshihisa , Gima Shin-ei , Kaga Makoto , Asaji Tetsuo , Ikeda Ryuichi , Nakamura Daiyu 
Published: February 2015

Abstract
The temperature dependence of the spin-lattice relaxation time (T1H) of 1H NMR measured in tetramethylammonium hexachloroplumbate(IV), (Me4N)2[PbCl6], showed a deep and a shallow minimum near 190 and 115 K, respectively. Since the presence of two kinds of crystallographically nonequivalent cations in the room-temperature Fd 3c unit cell has been reported, the deep T1H minimum was assigned to the overall reorientation of three quarters of the Me4N+ ions and the shallow minimum to that of the remaining cations. Two different temperature dependences of the chlorine NQR spin-lattice relaxation time (T1Q), attributable to a modulated electric-field-gradient by the protonic motion, were observed in (Me4N)2[MCl6] (M = Pb, Sn, Te). One is found in the Pb complex whose T1Q stems from the cationic motion responsible for the deep T1H minimum, and the other one is determined by the cationic motion giving the shallow T1H minimum. Although all room-temperature phases of these complexes are well described by the Fd 3c unit cell, the presence of different temperature dependences of T1Q suggests that the CH3 groups in the respective complexes take different orientations in the crystals
Solutions of Sodium in Liquid Ammonia as Described by a Hard Sphere Charge-Dipole Model in the Neutralizing Background
Authors: Golovko M. F. , Protsykevych L A. 
Published: February 2015

Abstract
The analytic solution of the mean spherical approximation obtained by us previously for the ion-dipole system in a neutralizing background is applied to study the structural, thermodynamic and dielectric properties of sodium-ammonia solutions. It is shown that the structure of ammonia is closepacked and changes little with ion concentration. The shape of the ion-ion distribution function changes from solvation behaviour with Debye-like asymptotics at low ion concentration to density ordering in the metalic region.
A Configurational Contribution to the Heat Capacity of Gaseous(HDO)2
Authors: Slanina Zdenek , Kalinichev Andrey G. 
Published: February 2015

Abstract
(HDO)2 can form two isomeric species, HOD.OHD and DOH.OHD. The species are studied in terms of the Bopp-Jancsö-Heinzinger potential. The deuterium-bonded structure is stabilized in zero-point vibrational energy by about 0.77 kJ mol-1 over the hydrogen-bonded one. In gas-phase the exactly equal stability of both structures would however be reached at a temperature of 638 K. The thermodynamic functions of HOD.OHD and DOH.OHD are different and, moreover, they essentially differ from the (overall) functions belonging to the equilibrium mixture of both structures (which is understood as one pseudospecies). For the heat capacity at constant pressure it is shown that a maximum of the difference between the pseudospecies' overall value and the HOD.OHD value appears at a temperature of about 39 K, amounting to some 4.6 J K-1mol-1
Spectroscopic Investigations of Intermolecular Interactions between Different Parts of Molecules
Authors: Luck W. A. P. , Peil S. 
Published: February 2015

Abstract
With the low temperature matrix techique we have observed different isolated IR OH vibration bands caused by van der Waals forces of single atom groups of the matrix molecules. With a series of different perhalogenated matrix molecules these different OH band frequency shifts ΔvOH can be correlated to OH interactions with C-F, C-Cl, C-Br resp. C-I groups. At higher temperatures T (solution spectra) the band positions of the different interactions become more similar because dv/d T increases with increasing interaction. This result clarifies why at room temperature band shoulders are observed and correlates these clearly to the different matrix bands and therefore to different interactions. These experiments demonstrate that intermolecular van der Waals potentials of asymmetric molecules cannot be approximated by one spheric potential but are angle dependent. This indicates the complexity of describe condensed media.
Interpretation of Vapor-Liquid Frequency Shift of CH stretching vibration of chloroform and Fluoroform
Authors: Tóth Katalin , Jancsó Gabor 
Published: February 2015

Abstract
The change in the frequency of the CH stretching vibration and in its anharmonicity constant, quadratic, cubic and quartic force constants and the equilibrium CH bond distance, on condensation, were investigated by performing model calculations for liquid chloroform and fluoroform. The interactions between the hydrogen atom and the CH oscillator, represented by a Morse potential, and the halogen atoms of its neighbor molecules were described by the sum of Lennard- Jones and Coulomb potential functions employed in molecular dynamics simulation. The calculations were carried out for different molecular arrangements in the liquid and have shown that mainly the size of the halogen atom, consequently the intermolecular distances, govern the direction of the CH vibrational frequency shift and of the change in the anharmonicity constant on the vapor-liquid transition. The pressure and temperature dependence of the CH stretching vibration was also studied for liquid chloroform. While the calculated pressure dependence is in good agreement with that observed, only the direction of the temperature dependence is in accordance with experimental observation.
Temperature Dependence of the Liquid-Vapor Isotopic Fractionation Factors in CD3H-CH4 and CD3F-CH3F Mixtures
Authors: Popowicz Anthony M. , Lub Ting-Hai , Bigeleisenc Jacob 
Published: February 2015

Abstract
The liquid-vapor isotope fractionation factors, LVIFF, α = CD3X/CH3X)1/(CD3X/CH3X)v, of CD3H-CH4 and CD3F CH3F mixtures have been measured from 102 160 K and 182 254 K, respectively. The results are in good agreement with previous vapor pressure ratios, VPIE, which cover the ranges 90 112 K and 132 211 K, respectively. Over the temperature ranges of the LVIFF measurements, ln α is negative for the CD3H-CH4 mixture and positive for the CD3F-CH3F mixture. There is significant curvature in a plot of T2 In α vs. T for the CD3H-CH4 mixture. The curvature is related to the densities of the liquid and vapor phases. It is shown that an expansion of the pair correlation function up to powers of the square of the densities of the liquid and vapor phases accounts for the T2 In α vs. T curvature and leads to In a equal to zero at the critical temperature. Correction of the LVIFF values of T2 In a for the density effect gives values for the contributions of translation, rotation and internal vibration in good agreement with previous cell model calculations. Similar treatment of the LVIFF data on the CD3F-CH3F mixture leads to the conclusion that the internal zero point energy effect on the differences in the heats of vaporization of CH3F and CD3F makes a small contribution to the overall difference in free energies of vaporization.
Monte Carlo Simulation of Magnesium Ion in 18.45 mol%Aqueous Ammonia Solution
Authors: Kheawsrikul Suchada , Hannongbua Supot V. , Rode Bernd M. 
Published: February 2015

Abstract
A Monte Carlo simulation has been performed for a magnesium ion in 18.45 mol% aqueous ammonia solution at 20 °C, using additive pairwise potential functions obtained from ab-initio calculations. The structural arrangement of the solvent molecules in the vicinity of the ion is discussed in terms of radial distribution functions and average molecular orientations. It was found that the first solvation shell of the ion consists of four water and three ammonia molecules, and the second shell of nine water and five ammonia molecules.
Solvent Isotope Effect on the Viscosity Coefficient B for Monovalent Ions in Water at 25 and 40°C
Authors: Ibuki K. , Nakahara M. 
Published: February 2015

Abstract
For heavy water solutions of LiCl, NaCl, KCl and CsCl at 25 and 40 C and KI at 25 °C the values of B(M + ) and B(X-) in the equation ]η/η0= 1 + A √c + [B(M + ) + B(X- )] c were determined under the conventional assumption B(K + ) = ß(Cl-). Here η0 is the viscosity of the solvent and c the molarity. The solvent isotope effect on the B values was found to be small. The B values for the medium-sized ions K + , Cs + , Br-, and I- were systematically more negative in heavy water than in light water. This is consistent with the idea that negative B values indicate the ability of the ion to break the structure of the water, the structure of heavy water being more developed than that of light water. For the tetraalkylammonium ions, Me4N + , Pr4N+ , and Bu4N + , on the other hand, the solvent isotope effect was small and random irrespective of the ion size. The temperature coefficients of B for the monatomic ions in heavy water were the same as for those in light water.
Conductance Studies on Aqueous Citric Acid
Authors: Apelblat Alexander , Barthel Josef 
Published: February 2015

Abstract
Conductance measurements of citric acid and neutral citrates (tri-lithium citrate, tri-sodium citrate and tri-potassium citrate) were performed in water at 278.15 to 308.15 K. The equilibrium constants for the primary and secondary steps of dissociation, Kx and K2, and the limiting conductances, λ0(H2Cit-), λ°(1/2 HCit2-), and λ0(1/3 Cit3-) are reported as a function of temperature. They are obtained by application of the Quint and Viallard conductance equation. The enthalpies of dissociation are estimated.
A Physico-Chemical Study of Concentrated Aqueous Solutions of Lithium Chloride
Authors: Tanaka Kazuko , Tamamushi Reita 
Published: February 2015

Abstract
The experimental values of density, viscosity, electric conductivity and diffusion coefficients of trace ions in aqueous solutions of lithium chloride in wide ranges of concentration and temperature are collected and discussed. The thermal expansivity and the activation energies of viscous flow, electric conductance and diffusion of trace ions show significant changes at a molality around 12 mol/kg, beyond which the hydration requirement is not satisfied
Effect of Pressure on the Self-Exchange Velocities in MD Simulations of Molten LiCl and LiBr Reflecting the Anomaly in the Conductivities
Authors: Okada Isao , Endoh Akira , Baluja Shipra 
Published: February 2015

Abstract
In molecular dynamics simulations of molten LiCl and LiBr at about 1000 K and various pressures the self-exchange velocity of unlike ion pairs divided by the molar volume increases with increasing pressure up to ca. 1000 MPa, reflecting the trend experimentally found for the electric conductivity up to 100 MPa. While the coordination of unlike ions is tetrahedral at low pressures, it is nearly octahedral at 2000 MPa.
Inelastic High-Energy Electron Spectrafrom Plane-Parallel Layer-Nonhomogeneous Surfaces
Authors: Afanas’ev V. P. , Naujoks D. 
Published: February 2015

Abstract
We consider inelastic backscattering of electrons with initial energy of tens and hundreds of keV by plane-parallel homogeneous and sandwiched targets. Basing on the invariance principle, we find expressions that describe the dynamics of the changes in the energy spectra of electrons reflected into a given solid angle that occur with increase of the thickness of films of different materials on substrates of finite and infinite thickness. We substantiate a procedure of linearizing the equations for the reflection function obtained by the method of invariant imbedding. We obtain an analytical solution of linearized equations in the form of a series in Legendre polynomials. A comparison with experimental data shows that the theory developed gives an adequate description of the process of electron backscattering.