bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron Spin Resonance of Mn2+ in Eu2M”3(NO3)12 · 24H2O (M” = Zn, Co) Single Crystals
Authors: Jain V. K.
Published: February 2015

Electron spin resonance of Mn2+ doped in Eu2M”3 (NO3)12.24H2O (M” = Zn, Co) single crystals has been studied at 295 and 77 K using an X-band spectrometer. The observation of resolved Mn2+ spectra in Eu2Co3(NO3)12.24H2O at 295 K have been interpreted in terms of random modulation of interaction between Mn2+ and divalent cobalt ions by the rapid spin-lattice relaxation of cobalt ions. T1 of divalent cobalt has been estimated to be ∼ 5×10−12 s at 295 K. The superposition model is applied to the zero-field splitting parameter D.- PACS: 76.30 F
Intermolecular Interactions of Xe Atoms Confined in One-dimensional Nanochannels of Tris(o-phenylenedioxy)cyclotriphosphazene as Studied by High-pressure 129Xe NMR
Authors: Kobayashi Hirokazu , Ueda Takahiro , Miyakubo Keisuke , Eguchi Taro
Published: February 2015

The pressure dependence of the 129Xe chemical shift tensor confined in the Tris(o-phenylenedioxy) cyclotriphosphazene (TPP) nanochannel was investigated by high-pressure 129Xe NMR spectroscopy. The observed 129Xe spectrum in the one-dimensional TPP nanochannel (0.45 nm in diameter) exhibits a powder pattern broadened by an axially symmetric chemical shift tensor. As the pressure increases from 0.02 to 7.0 MPa, a deshielding of 90 ppm is observed for the perpendicular

component of the chemical shift tensor δ⊥, whereas a deshielding of about 30 ppm is observed for the parallel one, δ‖. This suggests that the components of the chemical shift tensor, δ‖ and δ⊥, are mainly dominated by the Xe-wall and Xe-Xe interaction, respectively. Furthermore, the effect of helium, which is present along with xenon gas, on the 129Xe chemical shift is examined in detail. The average distance between the Xe atoms in the nanochannel is estimated to be 0.54 nm. This was found by using δ⊥ at the saturated pressure of xenon, and comparing the increment of the chemical

shift value in δ⊥ to that of a β -phenol/Xe compound.
The Influence of the Position of Oxygen on the Phase Behaviour of Benzylidene Anilines
Authors: Ajeetha N. , Pisipati V. G. K. M.
Published: February 2015

Synthesis and Characterization of N (p-n-alkyl benzylidene)-p-n-alkoxy anilines (n.Om), N (p-nalkoxy benzylidene)-p-n-alkoxy anilines (nO.Om) and N (p-n-alkyl benzylidene)-p-n-alkyl anilines (n.m), where n = m = either 4 or 5, has been carried out using thermal microscopy (TM) and differential scanning calorimetry (DSC). The results are discussed in the light of other experimental observations on N (p-n-alkoxy benzylidene)-p-n alkyl anilines (nO.m). It has been observed that the position of oxygen on either side of the rigid core of the benzylidene moiety plays an important role in the manifestation of different phase variants.
On Rüdenberg’s Integral Approximations and Their Unrestricted and Combined Use in Crystal Orbital Theories of Hartree-Fock Type
Authors: Koch Wolfhard , Frey Bastian , Ruiza Juan Francisco Sánchez , Scior Thomas
Published: February 2015

The analysis based on Rüdenberg’s well-known letter of 1951, which has been outlined for molecules in a preceding contribution, now will be transfered to translational periodic systems in one, two, or three dimensions. Again, when applied unrestrictedly to “Linear Combination of Atomic Orbitals” representations (LCAO) of both “Unrestricted” and “Restricted Hartree-Fock” pictures (UHF and RHF), Rüdenberg’s integral approximations of Mulliken type lead to a thorough interpretation of “Extended Hückel” crystal orbital theories (EHT). Moreover, Rüdenberg’s ideas provide us with “Unrestricted and Combined” extensions (U&C) of the widely-used approximation schemes “Zero Differential Overlap” (ZDO) and “Neglect of Diatomic Differential Overlap” (NDDO). An improved variant of EHT is also presented. Corresponding “Restricted and Combined” concepts (R&C), which overcome some shortcomings inherent in Rüdenberg’s original recipes, will be sketched.
1H and 13C NMR Spectral Studies on N-(Aryl)-Substituted Acetamides, C6H5NHCOCH3-iXi and 2/4-XC6H4NHCOCH3-iXi (where X = Cl or CH3 and i = 0, 1, 2 or 3)
Authors: Gowda B. Thimme , Usha K. M. , Jayalakshmi K. L.
Published: February 2015

35 N-(Phenyl)-, N-(2/4-chlorophenyl)- and N-(2/4-methylphenyl)-substituted acetamides are prepared, characterised and their NMR spectra studied in solution state. The variation of the chemical shifts of the aromatic protons in these compounds follow more or less the same trend with changes in the side chain. The chemical shifts remain almost the same on introduction of Cl substituent to the benzene ring, while that of methyl group lowers the chemical shifts of the aromatic protons. But only 13C-1 and 13C-4 chemical shifts in these compounds are sensitive to variations of the side chain. The incremental shifts in the chemical shifts of the aromatic protons and carbons due to -COCH3−iXi or NHCOCH3−iXi groups in all the N-(phenyl)-substituted acetamides, C6H5NHCOCH3−iXi (where X = Cl or CH3 and i = 0, 1, 2 or 3) are calculated. These incremental chemical shifts are used to calculate the chemical shifts of the aromatic protons and carbons in all the N-(2/4-chlorophenyl)- and N-(2/4-methylphenyl)-substituted acetamides, in two ways. In the first way, the chemical shifts of aromatic protons or carbons are computed by adding the incremental shifts due to -COCH3−iXi groups and the substituents at the 2nd or 4th position in the benzene ring to the chemical shifts of the corresponding aromatic protons or carbons of the parent aniline. In the second way, the chemical shifts are calculated by adding the incremental shifts due to -NHCOCH3−iXi groups and the substituents at the 2nd or 4th position in the benzene ring to the chemical shift of a benzene proton or carbon, respectively. Comparison of the two sets of calculated chemical shifts of the aromatic protons or carbons of all the compounds revealed that the two procedures of calculation lead to almost the same values in most cases and agree well with the experimental chemical shifts.
Theoretical Investigations of the EPR Parameters for Three Tetragonal Centers in CsCl:Cr3+ Crystal
Authors: Chen Wei-Dong
Published: February 2015

The electron paramagnetic resonance parameters zero-field splitting D and g factors g∥ and g⊥ of three tetragonal centers in CsCl: Cr3+ crystal at room temperature have been investigated by a two-spin-orbit (S. O.)-coupling parameter model. In this model, the contributions arising from the S. O. coupling of the central d3 ion and the ligands are included. For center III, the very small D of the [CrCl6]3− cluster may be due to the displacement (≈ 0.506 Å ) of the two substitutional Cl− ions along the tetragonal (C4) axis. For the centers I and II, the relatively larger D results from the contribution of two or one water molecules, i. e., corresponding to [CrCl6−n(H2O)n]n−3 with, n = 2 or 1 along the C4 axis, respectively. The reasonableness of the theoretical results is discussed.
Fluorescence Quenching and Solvation Processes of Fluorenone and 4-hydroxyfluorenone in Binary Solvents
Authors: Jozefowicza M. , Heldt J. R. , Karolczak J. , Heldt J.
Published: February 2015

Steady state and time-resolved spectroscopic measurements of fluorenone and 4-hydroxyfluorenone dissolved in binary nonpolar, polar and polar protic mixed solvents have been performed at room temperature. The absorption and emission spectra show that, apart from the free molecules, hydrogen bond complexes exist in the ground and excited states in the mixed solvents used. The data obtained were used to determine the stoichiometric equilibrium constants. The fluorescence decay data point that in the binary used solutions the radiation appears from an assembly of luminescence centers emitting fluorescence light of different wavelengths and decay times. Molecules forming simple hydrogen bond complexes (with fluorenone) show different photophysical properties from those where a proton-relay complex (with 4-hydroxyfluorenone) is established.
Effect of Modulation on Rayleigh-Benard Convection-II
Authors: Bhadauria B. S.
Published: February 2015

The linear stability of a horizontal fluid layer, confined between two rigid walls, heated from below and cooled from above is considered. The temperature gradient between the walls consists of a steady part and a periodic part that oscillates with time. Only infinitesimal disturbances are considered. Numerical results for the critical Rayleigh number are obtained for various Prandtl numbers and for various values of the frequency. Some comparisons with known results have also been made.
Density of Molten Terbium Chloride
Authors: Sato T. , Okamoto Y.
Published: February 2015

The density of molten terbium chloride at 993 to 1213 K, as measured by the γ -ray attenuation method, is found to be d = [3.937±0.028−(4.76±0.25) · 10−4T] g/cm3. The characteristic state parameters of molten TbCl3 are found to be 1129 K and 78.0 ml for T* and ν*, respectively.
Folded Solitary Waves and Foldons in the (2+1)-Dimensional Long Dispersive Wave Equation
Authors: Zhang J.-F. , Lu Z.-M. , Liu Y.-L.
Published: February 2015

By means of the Bäcklund transformation, a quite general variable separation solution of the (2+1)- dimensional long dispersive wave equation: λqt + qxx − 2q ∫ (qr)xdy = 0, λrt − rxx + 2r ∫ (qr)xdy= 0, is derived. In addition to some types of the usual localized structures such as dromion, lumps, ring soliton and oscillated dromion, breathers soliton, fractal-dromion, peakon, compacton, fractal and chaotic soliton structures can be constructed by selecting the arbitrary single valued functions appropriately, a new class of localized coherent structures, that is the folded solitary waves and foldons, in this system are found by selecting appropriate multi-valuded functions. These structures exhibit interesting novel features not found in one-dimensions. - PACS: 03.40.Kf., 02.30.Jr, 03.65.Ge.
Lithium Isotope Effect Accompanying Electrochemical Intercalation of Lithium into Graphite
Authors: Yanase Satoshi , Hayama Wakana , Oi Takao
Published: February 2015

Lithium has been electrochemically intercalated from a 1:2 (v/v) mixed solution of ethylene carbonate (EC) and methylethyl carbonate (MEC) containing 1 M LiClO4 into graphite, and the lithium isotope fractionation accompanying the intercalation was observed. The lighter isotope was preferentially fractionated into graphite. The single-stage lithium isotope separation factor ranged from 1.007 to 1.025 at 25 °C and depended little on the mole ratio of lithium to carbon of the lithium-graphite intercalation compounds (Li-GIC) formed. The separation factor inceased with the relative content of lithium. This dependence seems consistent with the existence of an equilibrium isotope effect between the solvated lithium ion in the EC/MEC electrolyte solution and the lithium in graphite, and with the formation of a solid electrolyte interfaces on graphite at the early stage of intercalation.
Molecular Orbital Estimation of Reduced Partition Function Ratios of Lithium Interacting with Aromatic Hydrocarbons with Condensed Benzene Rings
Authors: Oi Takao , Yanase Satoshi
Published: February 2015

Molecular orbital calculations at the B3LYP/6-311G(d) level were carried out to elucidate the lithium isotope effects accompanying chemical insertion of lithium from 1-methoxybutane solution containing lithium and naphthalene to graphite. The lithium atom between the graphene layers of graphite was modeled as lithium atoms in 1:1 complexes of lithium and simple aromatic hydrocarbons with condensed benzene rings. The 7Li-to-6Li isotopic reduced partition function ratio (RPFR) was found to be a decreasing function of the number of benzene rings adjacent to the benzene ring above which the lithium atom was located, and was “saturated” at 1.04570 at 25 °C. The most plausible lithium species in the 1-methoxybutane solution was a lithium atom interacting with a naphthalene molecule and solvated by a 1-methoxybutane molecule in the contact ion pair manner. Its RPFR value was 1.07126 at 25 °C. The two RPFR values gave a single-stage separation factor of 1.024 for the lithium isotopes, which agreed well with the experimental value of 1.023.
Phase Polymorphism of [Cd(DMSO)6](ClO4)2 Studied by Differential Scanning Calorimetry
Authors: Migdał-Mikuli A. , Mikuli E. , Szostak E. , Serwónska J.
Published: February 2015

Five phase transitions of [Cd(DMSO)6](ClO4)2 have been detected by differential scanning calorimetry, namely the three reversible transitions: stable KIa ↔ stable KIb at TC4 = 242 K, due to a change of the crystal structure, metastable KII ↔ metastable KIII at TC3 = 318 K, and metastable KII ↔ overcooled K0 at TC2 = 347 K, one irreversible transition: KIa ↔ K0 at TC1 = 376 K, and melting at Tt = 465 K. From the enthalpy changes of these transitions it can be concluded that K0 is a solid rotational phase and KII and KIII are most probably solid phases with a high degree of orientational disorder. The phases K0, KII, and KIII form an enantiotropic system, but they are metastable in relation to the phases KIa and KIb in the whole temperature range, so they form the monotropic system with them.
6-Methoxy-3,3’,3’-Trimethylspiro[2H-1-Benzopyran-2,1’[2]Oxaindan]: Separation Of Enantiomers, Circular Dichroism Measurements And Determination Of The Absolute Configuration
Authors: Voloshina Elena N. , Wang Yuekui , Voloshina Nikolai A. , Raabe Gerhard , Gais Hans-Joachim , Fleischhauer Jörg
Published: February 2015

The enantiomers of 6-methoxy-3,3’,3’-trimethylspiro[2H-1-benzopyran-2,1’[2]oxaindan] were separated with the high-pressure liquid chromatography method. Their optical properties were studied experimentally and by quantum-chemical calculations. The absolute configurations of the compounds were determined by comparison of the measured and calculated CD spectra.
On the Structure of the Electron
Authors: Lortz D.
Published: February 2015

Usually the electron is described as a mathematical point with charge, mass, spin angular momentum, and electromagnetic field. Because of the unbounded energies this causes mathematical difficulties [1]. These can be avoided by considering a finite radius. For a “free electron at rest” a classical relativistic model is presented where an axisymmetric torus models the electron. This configuration “differentially rotates” around its axis of symmetry with superluminal speed.
Theoretical Studies of the EPR g Factors and the Hyperfine Structure Constants of Cr3+ in MgS and SrS
Authors: Wu Shao-Yi , Gao Xiu-Ying , Yan Wei-Zi
Published: February 2015

The EPR g factors and the hyperfine structure constant A factors for Cr3+ in MgS and SrS are theoretically studied by using the two-spin-orbit (S.O.)-coupling-coefficient formulas for a 3d3 ion in octahedra based on the cluster approach. In these formulas, both the contributions due to the S.O. coupling coefficient of the central 3d3 ion and that of ligands are taken into account. Based on these studies, the g and A factors of Cr3+ in both MgS and SrS are satisfactorily explained. The results are discussed.
Dynamics of Combined Solitary-waves in the General Shallow Water Wave Models
Authors: Hong Woo-Pyo
Published: February 2015

We find new analytic solitary-wave solutions, having a nonzero background at infinity, of the general fifth-order shallow water wave models using the hyperbolic function ansatz method. We study the dynamical properties of the solutions in the combined form of a bright and a dark solitary-wave by using numerical simulations. It is shown that the solitary-waves can be stable or marginally stable, depending on the coefficients of the model.We study the interaction dynamics by using the combined solitary-waves as the initial profiles to show the formation of sech2-type solitary-waves in the presence of a strong nonlinear dispersion term. - PACS: 03.40.Kf, 02.30.Jr, 47.20.Ky, 52.35.Mw
NMR Relaxation Time Simulation for Different Models of Motion in (CH3)3NBH3
Authors: Goc Roman
Published: February 2015

Monte Carlo simulations of complex rotation of single −CH3 groups, −(CH3)3 groups and −BH3 groups were performed for trimethylamine borane (CH3)3NBH3. In the course of these simulations the correlation functions for different models of rotation were determined. Knowledge of these functions and of some data extracted from NMR experiments allowed for the calculation of the longitudinal magnetic relaxation time T1 as a function of temperature. The values of relaxation times obtained from Monte Carlo simulations are compared to experimental results published by other authors. There is a clear relation between the assumed model of rotation and the shape of the T1 curve versus temperature.
Photophysical Properties of new Polymerizable 1,8-Naphthalimides and their Copolymers with Methylmethacrylate
Authors: Grabchev Ivo , Staneva Desislava
Published: February 2015

In this paper we discuss the photophysical properties of some 4-nitro- and 4-allylamino-N-phenyl- 1,8-naphthalimides having different substituents in the phenyl ring, and their copolymers with methylmethacrylate in solid films. The influence of the substituents at the phenyl ring and the environment (methanol or polymer matrix) on the absorption and fluorescence properties is also discussed.
Higher Homologues of Mesomorphic Benzylidene Anilines. Manifestation of Smectic Polymorphism
Authors: Padmaja S. , Srinivasulu M. , Pisipati Venkata G. K. M.
Published: February 2015

The synthesis and characterisation of higher homologues of the well-known benzylidene anilines, viz. N-(p-n-tridecyloxy, tetradecyloxy, and hexadecyloxy benzylidene)-p-n-alkylanilines, 13O.m, 14O.m and 16O.m liquid crystalline compounds have exhibited mono, bi and tri phase variant smectic polymorphism. The different liquid crystalline phases are characterized by an optical polarising microscope equipped with a PC based temperature controller. The phase transitions are studied by using differential scanning calorimetry. The results are discussed in the light of the data available on other nO.m compounds.
Concentration and Temperature Dependence of Laurdan Fluorescence in Glycerol
Authors: Kozyra K. A. , Heldt J. R. , Heldt J. , Engelkec M. , Diehl H. A.
Published: February 2015

Steady-state and time-resolved fluorescence measurements have been performed on Laurdan, dissolved in viscous glycerol, as functions of temperature and concentration. The results indicate spectral heterogeneity of the Laurdan solution. The fluorescence decay time distribution is attributed to radiative deexcitation of spatial conformational forms of locally excited (LE) and charge transfer (CT) states, the S1(CT)EQ state being in thermodynamic and vibrational equilibrium. The lifetimes and contributions of the different fluorescence modes depend on concentration and temperature. The excitation and emission spectra show discontinuous changes with increase of the Laurdan concentration.We suppose that the observed changes are caused by the formation of Laurdan micelle aggregates.
Evidences of Conformational Fluctuations of 2-methylaminofluorenone and 2-dimethylaminofluorenone in Polar Solvents
Authors: Józefowicza M. , Heldta J. R. , Heldta J. , Heldta J.
Published: February 2015

The absorption and fluorescence spectra of 2-methylaminofluorenone (2MAFl) and 2-dimethylaminofluorenone (2DMAFl) were determined at 293 K in a variety of solvents with different polarities. The spectral data were used, in combination with the 2MAFl and 2DMAFl ground state dipole moment (μg), to evaluate μe of the S1 state, to determine the outer-sphere solvent reorganization energy λouter, and the intramolecular reorganization energies: λ1 (associated with vibrations for which hv < kT) and λi(hv > kT). At 77 K the fluorescence spectra in a non-polar solvent are shifted to longer wavelengths. In polar solvents, for both molecules the behavior is opposite. The fluorescence decay data for 2MAFl and 2DMAFl in non-polar solvents are very well fitted by oneexponential functions, while in polar solvents by two-exponential functions. The spectroscopic data distinctly show that both studied molecules in polar solvents form an inhomogeneous emitting system.
The Viscous Properties of Diols. IV. 1,2- and 1,4-Butanediol in Butanols Solutions
Authors: Czechowski Grzegorz , Jarosiewicz Paweł , Rabiega Arkadiusz , Jadżyn Jan
Published: February 2015

The paper presents the results of viscosity measurements performed on 1,2- and 1,4-butanediol in n-, s- and t-butanol solutions in the whole range of concentration, at different temperatures. The activation energy for viscous flow of the solutions and the viscosity excess were determined. The excess shows a peculiar behavior for 1,4-butanediol in t-butanol solutions.
Vibrational Properties of Hydrogen Astatide, HAt
Authors: Baran Enrique J.
Published: February 2015

A number of theoretical studies on the bond characteristics of HAt, the heaviest hydrogen halide, have recently been reported. On the basis of these data the force constant, mean amplitudes of vibration and thermodynamic functions of this molecule have been calculated. Some comparisons with the related lighter hydracids are made.
General Similarity Solution of the Fragmentation Kinetics Equation
Authors: Elhanbaly A. , Elgarayhi A.
Published: February 2015

In this article we have discussed a new application of Lie’s similarity method on the integrodifferential fragmentation equation. A wide variety of the similarity solutions of the fragmentation equation has been obtained. Some of them are compared with those obtained by other authors.
Investigations of the EPR g Factors for Er3+ in CaMoO4
Authors: Wu Shao-Yi , Dong Hui-Ning
Published: February 2015

The electron paramagnetic resonance (EPR) g factors g‖ and g⊥ for Er3+ in CaMoO4 are theoretically investigated by using the perturbation formulas of the g factors for a 4f11 ion in tetragonal symmetry. In these formulas, the contributions to the g factors arising from the second-order perturbation terms and the admixture of various states are considered. The crystal-field parameters for the tetragonally distorted tetrahedra are determined by using the superposition model and the structural data of the impurity Er3+ on the host Ca2+ site in CaMoO4. The calculated g factors agree with the observed values. The validity of the results is discussed.
Theoretical Investigation of the EPR g-factors for Yb3+ in YBa2Cu3O7-δ
Authors: Dong Hui-Ning , Wu Shao-Yi , Luo Xiao-Bing
Published: February 2015

The EPR g factors g‖, g⊥ for Yb3+ in YBa2Cu3O7−δ are studied with perturbation formulas based on the cluster approach of the spin-Hamiltonian parameters for a 4f13 ion in tetragonal symmetry. In these formulas, the contributions to the EPR parameters of the covalency effects, the admixture between the J = 7/2 and J = 5/2 states and the second-order perturbation terms are all included. The used crystal-field parameters are calculated with the superposition model and the local structural data of Yb3+ in YBa2Cu3O7−δ . The resulting EPR g factors for Yb3+ ions in the superconductor YBa2Cu3O7−δ agree reasonably with the experimental values. The results are discussed.
Lie Series Technique, Ordinary Differential Equations and Dynamical Integration
Authors: Steeb Willi-Hans
Published: February 2015

The Lie series technique is applied to solve a class of nonlinear differential equations.We show that it includes also the dynamical integration technique. Differential equations with chaotic behaviour are also considered with this technique. Finally first integrals and the Lie series technique is discussed.
Speed and Shape of Solitary Waves in Two-electron Plasmas with Relativistic Warm Ions
Authors: Chatterjee Prasanta
Published: February 2015

Large amplitude solitary waves are investigated in a relativistic plasma with finite ion-temperature and two temperature isothermal electrons. Sagdeev’s pseudopotential is determined in terms of the ion speed u. It is found that there exists a critical value of u0, the value of u at which (u’)2 = 0, beyond which the solitary waves cease to exists. The critical value also depends on parameters like the soliton velocity v, the fraction of the cold electron concentration μ, or the ratio of the cold and hot electron temperatures β .
Molecular Orientation of Some Fluorescent Dichroic Dyes in Nematic Liquid Crystal
Authors: Grabchev I. , Mykowska E. , Moneva I. , Bauman D.
Published: February 2015

Highly fluorescent dyes, derivatives of 1,8-naphthalimide and 3-benzanthrone, have been studied for use in liquid crystal displays of the “guest-host” type. Special attention has been given to the evaluation of the orientation of the dyes with planar molecular structure in the nematic liquid crystalline phase. By means of polarized absorption and emission spectroscopy, the order parameters SA, SF and D of the dyes in the liquid crystal mixture ZLI 1695 have been determined. Moreover, the absorption transition moment directions with respect to the long molecular axis of the dyes have been assigned.
Least-action Principle Applied to the Kepler Problem
Authors: Olszewski S.
Published: February 2015

The least-action principle is examined for the two-body Kepler problem. This examination allows one to couple the eccentricity parameter of the Kepler orbit with the size of the major semiaxis of that orbit. The obtained formula is applied to an estimate of eccentricities characteristic for a set of the planetary and satellitary tracks.
Theoretical Study of the Effect of Different α-Substituents on the Acetaldimine-Vinylamine Tautomeric System
Authors: Al-Omari Hamzeh S. M.
Published: February 2015

The Acetaldimine-Vinylamine tautomeric system has been studied by employing the MNDO semiempirical method. The imine structure was found to be energetically favorable, as indicated by the calculated heats of formation, Gibbs free energy, LUMO and HOMO, and charges. The substitution of F, Cl, CN, CH3, CF3, NO2 and BH2 at the α-position was found to affect the geometrical parameters. F and Cl substituents are found to favor the imine formation, while CF3, NO2, CN2 and BH2 favor the amine formation. The proton transfer in this tautomeric system is found to be easier (ΔH = 5.224 kcal/mol) than that in the keto-enol tautomeric system (ΔH = 11.1 kcal/mol).
Theoretical Investigations of the Spin Hamiltonian Parameters and the Local Structure of a Trigonal Co2+ Center in Bi4Ge3O12
Authors: Wu Shao-Yi , Dongb Hui-Ning
Published: February 2015

The spin Hamiltonian parameters anisotropic g factors g||, g⊥ and hyperfine structure constants A||

and A⊥, as well as the local structure of the trigonal Co2+ center in Bi4Ge3O12 (BGO) are theoretically

investigated by the perturbation formulas of the spin Hamiltonian parameters for a 3d7 ion in

trigonal symmetry, based on the cluster approach. It is found that the impurity Co2+ substituting the

host Bi3+ undergoes an off-center displacement ΔZ(≈ −0.132 Å ) away from the center of the oxygen

octahedron along the C3 axis. The spin Hamiltonian parameters based on the above displacement

show reasonable agreement with the observed values. The results are discussed.
On the Restricted and Combined Use of Rūdenberg’s Approximations in Crystal Orbital Theories of Hartree-Fock Type
Authors: Koch Wolfhard , Freyb Bastian , Ruiza Juan Francisco Sánchez , Sciorc Thomas
Published: February 2015

The analysis based on Rüdenberg’s well-known letter of 1951, which has been outlined for molecules in a preceding contribution, has now been transfered to translational periodic systems in one, two, or three dimensions. Entitled “On the Three- and Four-Center Integrals in Molecular Quantum Mechanics”, this letter explicitly presents two approximations only for four-center repulsion integrals. When applied to some types of three-center repulsion integrals, however, these two recipes still imply considerable oversimplifications. Using both one-electron and two-electron routes of Rüdenberg’s expansion, such shortcomings can be avoided strictly. Starting from a simple “Unrestricted and Combined” (U&C) approximation scheme introduced elsewhere, an improved “Restricted and Combined” (R&C) approximation picture for Fock-matrix elements now will be outlined, which does not tolerate any unnecessary oversimplifications. Although the simplicity of the U&C scheme is lost in this case, R&C-approximated Fock-matrix elements still can be constructed from one- and twocenter integrals alone in an effective way. Moreover, due to their dependence on a single geometric parameter, all types of two-center integrals can be calculated in advance for about one hundred fixed interatomic distances at the desired level of sophistication, and stored once and for all. A cubic spline algorithm may be taken to interpolate the actual integral value from each precomputed list.
Harmonic Interpolation, Bézier Curves and Trigonometric Interpolation
Authors: Hardy A. , Steeb W.-H.
Published: February 2015

A harmonic interpolation of a polygon (for odd and even numbers of points forming the polygon) used in computer graphics is derived from the primary permutation matrix using the spectral decomposition of the matrix. This is a technique to draw closed curves. We compare these curves with Bézier curves. We also show situations where the harmonic interpolation of a polygon is a more suitable alternative to B´ezier curves. Trigonometric Interpolation is another technique to draw curves. The relationship between trigonometric interpolation and harmonic interpolation is discussed.
Elliptic Function Solutions of (2+1)-dimensional Longwave – Shortwave Resonance Interaction Equation via a sinh-Gordon Expansion Method
Authors: Yan Zhenya
Published: February 2015

With the aid of symbolic computation, the sinh-Gordon equation expansion method is extended to seek Jacobi elliptic function solutions of (2+1)-dimensional long wave-short wave resonance interaction equation, which describe the long and short waves propagation at an angle to each other in a two-layer fluid. As a result, new Jacobi elliptic function solutions are obtained. When the modulus m of Jacobi elliptic functions approaches 1, we also deduce the singular oliton solutions; while when the modulus m→0, we get the trigonometric function solutions. - PACS: 02.30.Jr, 03.40.Kf
Defect Structure of the Tetragonal Cu2+ Center in PbTio3: Cu2+ Crystal
Authors: Wu Xiao-Xuan , Zheng Wen-Chen , Tang Sheng
Published: February 2015

The defect structure of the tetragonal Cu2+ center in PbTiO3: Cu2+ crystal is studied by analyzing the EPR g factors and hyperfine structure constants. From the study, we suggest that an oxygen vacancy occurs in the nearest-neighbors site of Cu2+ due to charge compensation, and that the offcenter displacement of Cu2+ is smaller than that of the replaced host ion Ti4+. The reasonableness of the defect structure is discussed.
Synthetic, Infrared, 1H And 13C NMR Spectral Studies on Potassium Salts of N-Chloroarylsulphonamides
Authors: Jyothi K. , Gowda B. Thimme
Published: February 2015

Several N-chloroarylsulphonamides of the configuration, 4-X-C6H4SO2(K)NCl・xH2O (where X = H, CH3, C2H5, F, Cl or Br) and i-X, j-YC6H3SO2(K)NCl・xH2O (where i-X, j-Y = 2,3-(CH3)2; 2,4- (CH3)2; 2,5-(CH3)2; 2-CH3,4-Cl; 2-CH3,5-Cl; 3-CH3,4-Cl; 2,4-Cl2 or 3,4-Cl2) are prepared, characterised, and their infrared spectra in the solid state and NMR spectra in solution are measured and correlated. Comparison of the infrared spectra of the potassium salts of N-chloro-arylsulphonamides with the corresponding arylsulphonamides shows that the strong absorptions in the range 947 - 933 cm−1 are due to N-Cl stretching vibrations. The effect of ring substitution on the N-Cl frequencies is non-uniform. The frequencies in the ranges 1404 - 1370 cm−1 and 1149 - 1125 cm−1 are respectively assigned to S=O asymmetric and symmetric vibrations. The effect of substitution in the phenyl ring in terms of electron withdrawing and electron donating groups is non-systematic. Empirical correlations relating the chemical shifts to the structures are considered. The chemical shifts of aromatic protons and carbons in all the N-chloroarylsulphonamides have been calculated by adding substituent contributions to the shift of benzene, as per the principle of substituent addition. Considering the approximation made, the agreement between the calculated and experimental chemical shifts is reasonably good.
Studies on Room Temperature Ferroelectric Liquid Crystal, 12CN5(R*)
Authors: George A. K. , Pisipati Venkata G. K. M. , Carboni C. , Harthi S.H. Al , Naciri J.
Published: February 2015

Characterization studies are performed on a ferroelectric liquid crystal, 12CN5(R*). Phase sequence and transition temperatures are obtained by polarized thermal microscopy. Temperature variation of spontaneous polarization and tilt angle in the smectic C* phase are found to agree with the mean-field predictions. Results obtained for the variation of the switching time and torsional viscosity with temperature are also presented.
The Electron Paramagnetic Resonance Spectrum of γ-Irradiated Dimethyl Malonic Acid
Authors: Aşik Biray , Birey Mehmet
Published: February 2015

The electron paramagnetic resonance of γ -Irradiated single crystals of dimethyl malonic acid [(CH3)2C(COOH)2] has been studied for different orientations of the crystal in a magnetic field. The radicals produced by gamma irradiation have been investigated between 123 and 300 K. The spectra were found to be temperature independent, and radiation damage centres were attributed to [(CH3)2C(COOH)2]+ radicals. The g factor and hyperfine coupling constants were found to be almost isotropic with average values g = 2.0036, a(COOH)2 = 0.5 mT, a(CH3)2 = 2.1 mT, respectively, and spin density ρ = 91% of the [(CH3)2C(COOH)2]+ radical.
Variable Separation Approach for a Differential-difference Asymmetric Nizhnik-Novikov-Veselov Equation
Authors: Qian Xian-min , Lou Sen-yue , Hu Xing-biao
Published: February 2015

The multi-linear variable separation approach is applied to a differential-difference asymmetric Nizhnik-Novikov-Veselov equation. It is found that the solution formula ANNV equation is rightly the semi-discrete form of the continuous one which describes some types of special solutions for many (2+1)-dimensional continuous systems. Moreover, it is different but similar to that of a special differential-difference Toda system. Thus abundant semi-discrete localized coherent structures of the ANNV equation are easily constructed by appropriately selecting the arbitrary functions appearing in the final solution formula. A concrete method to construct multiple localized discrete excitations with and without completely elastic interaction properties are discussed. It is found that for some types of bounded solitoff modes, they can exchange solitoffs, move in new different directions, extend the lengths of solitoffs, etc. after finishing their interactions. - PACS numbers: 0230, 0220, 0540
Mesomorphism in a Binary Mixture of Non-mesogens: A Dielectric Spectroscopy Investigation
Authors: George A. K. , Potukuchi D. M. , Al-Harthi S.H. , Carboni C.
Published: February 2015

We report on thermal microscopy and low frequency dielectric relaxation of a liquid crystal formed by mixing cholesterol with 1-hexadecanol. Though both components are non-mesogenic, the mixture is found to exhibit a smectic A phase. A 1 Vp-p a. c signal of 100 kHz was used to study the dielectric response, while the frequency was varied from 5 Hz to 10 MHz for relaxation studies. The dielectric loss in the smectic A phase exhibits a single Debye-type off-centered relaxation in the MHz region. The temperature variation of the relaxation frequency is presented by Arrhenius plots, and the corresponding activation energy is estimated. The temperature variation of the dielectric strength (Δε =ε0 −ε∞) and the distribution parameter α in the smectic phase are estimated. The mesomorphic behavior of binary systems, where both components are non-mesomorphic, is discussed.
Comparison of Dielectric Properties of Three Alkyl and Alkoxy Azoxybenzenes (nAOBs and nOAOBs, n = 5, 6, 7) in the Isotropic and Liquid Crystalline Phases
Authors: Urban Stanisław , Czub Joanna , Gestblom Bo
Published: February 2015

Results of dielectric studies of three 4,4’-di-n-alkyl-azoxybenzenes (nAOB) and 4,4’-di-n-alkoxyazoxybenzenes (nOAOB), n = 5, 6 and 7, are presented. The nAOB compounds exhibit positive, and the nOAOBs negative dielectric anisotropy in the nematic phase. In the smectic A phase of 7AOB the anisotropy changes its sign, whereas in the smectic C phase of 7OAOB it persists negative; moreover, in the latter case the perpendicular component of the permittivity increases with respect to the value of the nematic phase. This may be due to parallel dipole-dipole correlation of the perpendicular components involved by the layer arrangements in both smectic phases. For all substances a systematic decrease of the permittivity components with chain length was observed. Different types of smectic order in the 7th members of both series are discussed in relation to the mean-field theory developed recently by Govind and Madhusudana. The dielectric relaxation times and activation enthalpies characterizing the molecular rotation around the principal inertia axes are given.
Determination of Diffusion Coefficients of Fluorescently Labelled Molecules in Lipid Membranes Using Confocal Scanning Laser Microscopy
Authors: Öncan N. , Player M.A. , Macdonald A.G.
Published: February 2015

A series of liposomes has been studied by the Fluorescence Recovery after Photobleaching technique using confocal scanning laser microscopy. Both mobile and immobile specimens of lipid membranes have been examined. The specimens consisted of liposomal suspensions incorporating mixtures of the phospholipids dioleoyl phosphatidylcholine (DOPC) and distearoyl phosphatidylcholine (DSPC) with the aminolipid dihexadecanol glycerophospho-ethanolamine (DHPE). The measurements reported provide information about the effective diffusion coefficients, which vary from 0.2 · 10−10 cm2s−1 to 3.2 · 10−10 cm2s−1. They were highly dependent on the ratio DSPC:DOPC. A simple theoretical model of 1-D diffusion was applied for the calculation of the effective diffusion coefficients. The measurements show that it is possible to use straightforward procedures with an unmodified commercial confocal microscope to determine diffusion coefficients of biological specimens.
Relation between Pauling and Coulson Bond Orders in Benzenoid Hydrocarbons
Authors: Gutman Ivan , Furtula Boris , Radenković Slavko
Published: February 2015

The relation between Pauling and Coulson bond orders in benzenoid hydrocarbons is examined. The carbon-carbon bonds of benzenoid hydrocarbons have to be classified into three classes, depending on the number of attached hydrogen atoms. Within each class the correlation between the bond orders is linear. The results can be used to rationalize the recently discovered correlation between the energy and electron contents of rings. An approximate expression for the total π-electron energy is also deduced.
Spectrophotometric Study of Nd2+ Ions in LiCl-KCl Eutectic Melt
Authors: Hayashi Hirokazu , Akabori Mitsuo , Ogawa Toru , Minato Kazuo
Published: February 2015

A UV and visible spectrophotometric study was made in order to prove the existence of Nd2+ and clarify the equilibrium among Nd metal, Nd2+, and Nd3+ in LiCl-KCl eutectic melt. Spectra assigned to Nd2+ were observed for NdCl2 in (LiCl-KCl)eut. and Nd- NdCl3 in (LiCl-KCl)eut. melts. Black corrosion products were observed on the surface of the glass cells used for the measurements, where the spectra assigned to Nd2+ were observed. X-ray diffraction measurements and electron-probe micro-analyses of the corroded glass cells revealed that the corrosion products contained NdOCl.
New Solitary-Wave Solutions for the Generalized Reaction Duffing Model and their Dynamics
Authors: Kim Jong-Jae , Hong Woo-Pyo
Published: February 2015

We find new analytic solitary-wave solutions, having a nonzero background at infinity, of the generalized reaction Duffing model using the auxiliary function method. We study the dynamical properties of the solitary-waves by numerical simulations. It is shown that the solitary-waves can be stable or unstable depending on the coefficients of the model. We study the interaction dynamics by using the solitary-waves as initial profiles to show that the nonlinear terms may act as an effective driving force. - PACS numbers: 03.40.Kf, 02.30.Jr, 47.20.Ky, 52.35.Mw
Unified Treatment for Two-Center One-Electron Molecular Integrals Over Slater Type Orbitals with Integer and Noninteger Principal Quantum Numbers
Authors: Özdoğan Telhat
Published: February 2015

A unified expression has been obtained for two-center one-electron molecular integrals over Slater type orbitals with integer and noninteger principal quantum numbers by the use of the expansion formula for the product of two normalized associated Legendre functions. The presented expression for two-center one-electron molecular integrals contains the expansion coefficients akk'
us and Mulliken integrals An and Bn. The efficiency of the presented calculation has been compared with that of other methods, indicating good convergence and great numerical stability for a wide range of quantum numbers, orbital exponents and internuclear distances
Theoretical Interpretation of the EPR Parameters for Dy3+ Ion in LuPO4 Crystal
Authors: Dong Hui-Ning , Du Hui-Ping , Wu Shao-Yi , Li Peng
Published: February 2015

Based on the superposition model, in this paper the EPR parameters gII and g⊥ of Dy3+, and the hyperfine structure constants AII and A⊥ of 161Dy3+ and 163Dy3+ in LuPO4 crystal are calculated by perturbation formulas from the crystal-field theory. In the calculations, the contributions of various admixtures and interactions such as J-mixing, mixtures among states with the same J-value, twoorder perturbation, covalency as well as local lattice relaxation are considered. The calculated results agree reasonably with the observed values
Electron Paramagnetic Resonance Study of Defects in γ-irradiated Marine Mussel (Mytilus galloprovincialis) and Scallop (Pecten jacobaeus) Shells
Authors: Köseoğlu R. , Köksal F. , Birey M.
Published: February 2015

EPR studies have been performed on some gamma-irradiated marine mussels (Mytilus galloprovincialis) and scallops (Pecten jacobaeus) from the families of Mytilidae and Pectinidae, respectively. Before γ-irradiation, the EPR lines of Mytilus galloprovincialis indicated the existence of Mn2+ ions, which were not observed in the powders of scallop shells. γ -irradiation induced defects in powders of Mytilus galloprovincialis shells, were attributed to orthorhombic CO−
3 , axial CO3−
3 , orthorhombic CO−
2 , freely rotating CO−
2 , freely rotating SO−
2 , axial SO−
3 , isotropic PO2−
4 and organic free radicals. γ -irradiation induced defects in powders of Pecten jacobaeus shells were attributed to orthorhombic CO−
3 , axial CO3−
3 , orthorhombic CO−
2 , freely rotating CO−
2 , freely rotating SO−
2 , and axial SO−
3 free radicals. The EPR parameters of the free radicals were compared with literature data on similar defects
An NMR solid-echo Study of Guanidinium Cation Reorientation in [C(NH2)3]3Sb2Cl9
Authors: Bilski P. , Olszewskia M. , Sergeev N. A. , Wa̻sicki J.
Published: February 2015

The NMR solid-echo polycrystalline tris-guanidinium nonachlorodiantimonate (III) has been studied in a wide temperature range. The temperature dependences of a time position and an amplitude of solid-echo are characterized by minima at ca. 143 K and 273 K, which are assigned to the reorientation of two dynamically inequivalent guanidinium cations [C(NH2)3]+. The motional parameters of the two types of guanidinium cations have been determined. -PACS: 64.70K; 76.60.E
Experimental Stark Widths and Shifts in the 3p3D – 3d 3Fo O III Transition
Authors: Bukivić S. , Srećković A. , Djeniže S.
Published: February 2015

Stark widths (W) and shifts (d) of 3 doubly ionized oxygen (O III) spectral lines (326.085 nm, 326.532 nm and 326.720 nm) in the 3p3D-3d 3Fo transition have been measured in the optically thin helium-oxygen plasma created in a linear, low-pressure, pulsed arc discharge at a 26 000 K electron temperature and 1.1 · 1023 m−3 electron density. Our Stark shifts are the first measured data at an electron temperature smaller than 30 000 K. No theoreticalW and d data exist in this O III transition. Our W and d values are compared with the existing experimental data. On the basis of the found agreement among the experimental W and d values at a 26 000 K electron temperature we have evaluated their dependence on the electron temperature ranged between 10 000 K and 50 000 K
Local Structure of Molten CdCl2 Systems
Authors: Okamoto Y. , Shiwaku H. , Yaita T. , Suzuki S. , Minato K. , Tanida H.
Published: February 2015

The local structure of molten CdCl2 was investigated by X-ray absorption fine structure (XAFS) and X-ray diffraction(XRD) analyses. The nearest Cd2+-Cl− distance decreases from 2.61 Å in the room temperature solid state to 2.47 - 2.50 Å in the molten state. The coordination number decreases from 6 in the solid to 4 in the melt. The obtained structural parameters from the XAFS and the XRD analyses suggest that a tetrahedral coordination (CdCl4)2− is predominant in molten CdCl2. The XAFS result of a molten 50%CdCl2-KCl mixture shows that the 4-fold (CdCl4)2− structure holds also in the mixture
A Theoretical Study of Substituted Cyclobutanones and Their Enols
Authors: Sway Mohammad I. , Al-Shawabkeh Iyad D. , Khalil Salim M.
Published: February 2015

MINDO-Forces calculations have been performed with complete optimization of the geometry on cyclobutanone and its enol counterpart, perfluorination of cyclobutanones and enol counterparts, and X-cycolobutanones and their X-enols, where X is NO2, CF3, CN, OH, NH2 and F. It was found that ketone is more stable than its enol counterpart. Perfluorination destabilizes ketone on the expense of enol. These results agree with experimental and theoretical calculations. Electron releasing substituents (NH2, OH, F) stabilize cyclobutanone, while electron withdrawing substituents (CF3, NO2) destabilize it. CN substituents have almost no effect on the stabilization of this keto-enol system. Geometrical parameters, heats of formation, electron densities and Gibbs free energy are reported
Structural Studies on N-(2,4,5-trichlorophenyl)-2-Chloro- and 2,2,2-trichloroacetamides and N-Chloro-N-(2,4,5-trichlorophenyl)-2-Chloroacetamide
Authors: Gowda B. Thimme , Svoboda I. , Fuessa Hartmut
Published: February 2015

The effect of N-chloro, side chain and sites of ring substitutions on the crystal structure of N-(trichlorophenyl)-2-chloro and 2,2,2-trichloroacetamides has been studied by determining the crystal structure of N-(2,4,5-trichlorophenyl)-2-chloroacetamide, 2,4,5-Cl3C6H2.NHCO.CH2Cl (N245TCPCA), N-chloro-N-(2,4,5-trichlorophenyl)-2-chloroacetamide, 2,4,5-Cl3C6H2.NClCO. CH2Cl (NC245TCPCA) and N-(2,4,5-trichlorophenyl)-2,2,2-trichloroacetamide, 2,4,5-Cl3C6H2. NHCO.CCl3 (N245TCPTCA). The crystal type, space group, formula units and lattice constants in Å are: N245TCPCA: monoclinic, P21/n, Z = 4, a = 4.732(1), b = 29.522(3), c = 7.734(1), β = 108.33(1)◦; NC245TCPCA: monoclinic, P21/c, Z = 4, a = 15.965(3), b = 9.398(1), c = 7.352(2), β = 91.51(2)◦; N245TCPTCA: orthorhombic, Pmc21, Z = 4, a = 6.945(1), b = 11.370(3), c = 15.555(3). The results are compared with the structure of N-(phenyl)- acetamide, N-(phenyl)-2,2,2-trichloroacetamide, N-(2-chlorophenyl)-2,2,2-trichloroacetamide, N-(4-chlorophenyl)-2,2,2-trichloroacetamide, N-(2,6-dichlorophenyl)-2,2,2-trichloroacetamide, N-(2,4,6-trichlorophenyl)-acetamide, N-(2,4,6-trichlorophenyl)-2-chloroacetamide and N-(2,4,6- trichlorophenyl)-2,2,2-trichloroacetamide. The comparison of the bond parameters reveal that there are significant changes by substitution in both the ring and side chain of the amides and by N-chlorination. But to draw general conclusions further, substantial work is needed with varying substitutions