Volume 60, Issue 11-12

We find new analytic solitary-wave solutions of the higher order wave equations of Korteweg - De Vries (KdV) type (I), using the auxiliary function method. We study the dynamical properties of the solitary-waves by numerical simulations. It is shown that the solitary-waves are stable for wide ranges of the model coefficients. We study the dynamics of the two solitary-waves by using the analytic solution as initial profiles and find that they interact elastically in the sense that the mass and energy of the system are conserved. This leads to the possibility of multi-soliton solutions of the higher order KdV type (I), which can not be found by current analytical methods. - PACS numbers: 03.40.Kf, 02.30.Jr, 47.20.Ky, 52.35.Mw

By using the truncated Painlevé expansion analysis an auto-Bäcklund transformation is found for the nonlinear Schrödinger equation with varying dispersion, nonlinearity, and gain or absorption. Then, based on the obtained auto-Bäcklund transformation and symbolic computation, we explore some explicit exact solutions including soliton-like solutions, singular soliton-like solutions, which may be useful to explain the corresponding physical phenomena. Further, the formation and interaction of solitons are simulated by computer. - PACS Nos.: 05.45.Yv, 02.30.Jr, 42.65.Tg

In this paper, new analytical solutions of the nonlinear Schrödinger equation model are obtained. The properties of the new exact solutions are shown by some figures.

The coexistence of gaseous and liquid phases in an isobaric process are investigated by applying the thermodynamic functions of the Redlich-Kwong equation. The boiling temperatures and the enthalpy changes of vaporization of 45 substances are obtained by numerical calculations. The results agree with the experimental data within a few percent for the 45 considered substances. Some thermodynamic quantities for C 3 H 6 at 1 atm are calculated numerically as a function of T and drawn graphically. The Gibbs free energy indicates a polygonal line; entropy, volume and enthalpy jump from the liquid to the gaseous phase at the boiling point. The heat capacity does not diverge to infinity but shows a finite jump at the boiling point. This suggests that a first-order phase transition may occur at the boiling point.

Three kinds of acoustic waves are known: bulk waves, pseudo-surface waves and surface waves. A plane wave section of a constant-frequency surface of a film serves as a hint for the expected nature. Calculations based on slowness curves of films reveal frequency ranges where each type of acoustic waves is predominant. Dispersion curves and displacement acoustic waves are calculated and commented in each frequency interval for different coated materials. Both dispersion and sagittal elliptical displacement are sensitive and depend on diagrams mentioned above. Silver and aluminium thin films having different anisotropy ratios, namely 2.91 and 1.21, are retained for illustration.

A new method for theoretical examination of thermal inter-conversions via the space structure vibration excitation-relaxation stochastic optimization method has been proposed. The software to perform implementation of the methodology has been developed and tested on a silica 27SiO 2 cluster. A set of thermodynamically probable space structures of amorphous silica particles and temperatures of their inter-conversions has been simulated. The simulated space structures have been verified by comparison of calculated inelastic neutron scattering spectra of different highly dispersed silicas with experimental ones.

We report on modeling efforts and molecular dynamics computer simulations of the structure and self-diffusion of p-xylene in OH-free Si-MCM-41 as a function of loading. Both the guest molecules and Si-MCM-41 are modeled as flexible entities. With this newly developped intermolecular force field the average potential energy of p-xylene in the pore increases with increasing loading. The adsorption of p-xylene in MCM-41 is primarily associated with the van der Waals interactions of the model, whereas the contribution from electrostatic interactions is relatively small (about 2 kcal/mol), in accordance with other aromatic hydrocarbons adsorbed in zeolite catalysts. The calculated selfdiffusion coefficients of p-xylene in Si-MCM-41 are well comparable with diffusion coefficients of pyridine in MCM-41 and of the same order of magnitude as in liquid p-xylene. Increasing the loading results in non-negligible mutual p-xylene interaction, thus leading to a decrease of the self-diffusion coefficient.

The change in the number of reduction electrons of ubiquinone,0 (7.5・10 −6 mol/l) due to the presence of nucleosides or nucleic acid bases is measured coulometrically. The number of the reduction electrons varies from 2 - 1.72. The results are explained in terms of molecular interactions present between the two components of the mixture even at low concentrations.

The force constants of the internal coordinates of octahedral XY 6 molecules and complex ions were calculated by using the GF matrix method. The matrix solutions were found by means of a computer program using the Newton-Raphson method. From the calculations it has been observed that the bond stretch force constants of octahedral XF6 molecules and XY 6 complex ions having the same centre X atom decrease with the increasing molar mass of the centre X atom for the former and the ligand Y atom for the latter, respectively. This was attributed to the slowing down of the molecule with increasing molar mass of the molecule as the whole. In addition we have concluded that the difference of squares of the vibration frequencies ν 1 and ν 2 of octahedral XY 6 complex ions decreases with the increasing mass of the Y atom since the interaction force constant of these ions decreases with the increasing mass.

The EPR g factors g || , g ⊥ and zero-field splitting D of trigonal Cr 3 +-M + (M + = Li + , Cu + , Na+) and Cr 3 +-VB-M 3 + (M 3+ = Cr 3+ , In 3+ , Sc 3+ , Y 3+ , Lu 3+ ; VB denotes the B 2+ vacancy) centers in some CsBX 3 (B = Mg, Cd; X = Cl, Br) crystals are calculated from high-order perturbation formulas based on the two-spin-orbit coupling parameter model of the 3d 3 ion in trigonal symmetry. From the calculations, these EPR parameters are reasonably explained and the local lattice distortions caused by the charge compensators M+ or VB are estimated. The results are discussed.

The optical spectra and EPR parameters of trigonal Yb3 + centers in KMgF 3 and KZnF 3 crystals are calculated in a unified way, based on the crystal-field theory. The results agree reasonably with the observed values. The results are discussed.

The free radical copolymerisation of five fluorescent 4-allylamino-N-phenyl-substituted 1,8-naphthalimide dyes (MDs) with methylmethacrylate (MMA) has been investigated. The utility of the copolymers prepared as fluorescent component in polymer/liquid crystal systems has been investigated. The basic photophysical properties of monomeric dyes, poly(MMA-co-MD) and poly(MMAco- MD)/liquid crystal mixtures are discussed. The influence of poly(MMA-co-MD) on the phase transition temperature from the nematic to the isotropic state of poly(MMA-co-MD)/liquid crystal mixtures have also been investigated.

The structural, dielectric and conductive properties of [(CH 2 ) 3 (NH 3 ) 2 ]Cu(II)Cl 4 have been studied. The material shows an order-disorder transition at T 1 = (333±2) K and a ferroelectric phase transitions at T 2 = (434±3) K. Results of differential thermal analysis, infrared spectroscopy, X-ray diffraction, AC conductivity and permittivity measurements are reported and discussed. The conductivity results are interpreted in terms of barrier hopping at low and intermediate temperatures, and band-type conduction at high temperatures. - PACS: 81.05.-t, 77.22.-d

The electrical conductivity of molten CO(NH 2 ) 2 -MNO 3 (M = Li, Na, NH 4 ) with various nitrate contents has been measured at 358 - 393 K. For Li and Na the conductivity increased with increasing concentration of urea [CO(NH 2 ) 2 ], whereas for NH 4 the conductivity decreased with increasing concentration of urea. The relationship between the conductivity and the temperature can be expressed by κ = κ o exp(−E κ /RT). For the mole fractions 0.7, 0.8, and 0.9 of urea, the activation energies E κ are 31.28, 25.91, and 22.96 kJ/mol for the CO(NH 2 ) 2 -LiNO 3 system, and 32.64, 30.51, and 25.40 kJ/mol for the CO(NH 2 ) 2 -NaNO 3 system, whereas for the mole fractions 0.5, 0.7, and 0.8 of urea the activation energies are 20.39, 19.73, and 18.95 kJ/mol for the CO(NH 2 ) 2 -NH 4 NO 3 system. The more stable the forming complex is, the lower is the conductivity. The conductivities are in the order CO(NH 2 ) 2 -NH 4 NO 3 > CO(NH 2 ) 2 -NaNO 3 > CO(NH 2 ) 2 -LiNO 3 .

The electrodeposition of magnetic films of Co-Zn in zinc chloride-dimethylsulfone (ZnCl 2 - DMSO 2 ) molten salt electrolytes with added CoCl2 has been studied. The phase diagram of ZnCl 2 - DMSO 2 molten salts was determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Various compositions of alloys with different deposition potentials on the electrode surface have been studied by cyclic voltammetry. Either the constant potential method or the pulse potential method of plating can be used for electrodepositing Co-Zn thin films. The surface morphologies and magnetic properties have been studied. It has been shown that compact needle-type Co-Zn thin films are obtained at a constant potential of −0.1 V. Compact and uniform Co-Zn thin films are obtained by pulse electrodeposition. The magnetic properties of these films show higher coercive forces (H c ) and smoother domains than those obtained by the constant potential method.

Unrestricted Density Functional (B3LYP) calculations with the 6-311G(d) basis were done for benzene (C 6 H 6 ) with successive elongation of one C-H bond. Gradual increase in the total energy resulted til C-H bond length of about 3.7 Å , followed by a sudden decrease in energy on further elongation of the bond. The estimated activation energy for the reaction was 152.346 kcal/mol, much higher than the value calculated with the semiempirical PM3 method.

The mean amplitudes of vibration of [NH 3 F] + and [NH 3 Cl] + were calculated from known spectroscopic and structural data in the temperature range between 0 and 1000 K. The results are compared with those of related species and the bond peculiarities are also briefly discussed. Mean amplitude values for the NH4 + cation, at some selected temperatures, are also reported.

We apply genetic algorithms to find the value where the CHSH inequality is violated.