Volume 59, Issue 11

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

Starting from a quite universal formula, which is valid for some quite universal (2+1)-dimensional physical models, the interactions among different types of solitary waves like peakons, dromions, and compactons are investigated both analytically and graphically. Some novel and interesting features are revealed. The results show that the interactions for peakon-dromion, compacton-dromion, and peakon-compacton may be completely inelastic, not-completely elastic or completely elastic. - PACS numbers: 05.45.Yv, 02.30.Jr.

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 a kk' us and Mulliken integrals A n and B n . 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

To explain the difference between leptons and quarks, it is assumed that electroweak gauge bosons, leptons and quarks are composites of elementary fermionic constituents denoted by partons (not to be identified with quarks) or subfermions, respectively. The dynamical law of these constituents is assumed to be given by a relativistically invariant nonlinear spinor field theory with local interaction, canonical quantization, selfregularization and probability interpretation. According to the general requirements of field operator algebraic theory, this model is formulated in algebraic Schroedinger representation referred to generating functionals in functional state spaces. The derivation of the corresponding effective dynamics for the composite particles is studied by the construction of a map between the spinor field state functionals and the state functionals of the effective theory for gauge bosons, leptons and quarks. A closer examination of this map shows that it is then and then only selfconsistent if certain boundary conditions are satisfied. The latter enforce in the case of electroweak symmetry breaking the difference between lepton and quark states. This difference can be analytically expressed as conditions to be imposed on the wave functions of these composite particles and leads ultimately to the introduction and interpretation of color for quarks, i.e., the characteristic of their strong interaction

Based on the superposition model, in this paper the EPR parameters g II and g ⊥ of Dy 3+ , and the hyperfine structure constants A II and A ⊥ of 161 Dy 3+ and 163 Dy 3+ in LuPO 4 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

The zero-field splitting D, g factors g II and g ⊥ and the local structure near Fe + on the Zn 2+ site of ZnSiP 2 are calculated from high-order perturbation formulas of the EPR parameters for a 3d 7 ion in tetragonally distorted tetrahedra based on the cluster approach. According to these studies, we find that the impurity-ligand bonding angle α loc related to the fourfold axis is about 58.05 ◦ in the studied Fe + impurity center, which is larger than the metal-ligand bonding angle α h (≈ 56.65 ◦ ) in pure ZnSiP 2 . The EPR parameters based on the above angle αloc agree well with the observed values. The errors of the results are analyzed

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 Mn 2+ 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 CO 3− 3 , orthorhombic CO − 2 , freely rotating CO − 2 , freely rotating SO − 2 , axial SO − 3 , isotropic PO 2− 4 and organic free radicals. γ -irradiation induced defects in powders of Pecten jacobaeus shells were attributed to orthorhombic CO − 3 , axial CO 3− 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

In this paper, the EPR g factors g II and g ⊥ of Yb 3+ and hyperfine structure constants A II and A ⊥ of 171 Yb 3+ and 173 Yb 3+ in KMgF 3 crystal are calculated from the two-order perturbation formulae. In these formulae, the contribution of the covalence effects, the admixture between J = 7/2 and J = 5/2 states as well as the second-order perturbation are included. The needed crystal parameters are obtained from optical spectra. The calculated results agree reasonably with the observed values

The EPR parameters (zero-field splitting D and g factors g II , g ⊥ ) of Co 2+ ions in CdS and CdSe semiconductors are calculated from the high-order perturbation formulas based on the cluster approach for a 3d 7 ion in trigonal symmetry. These formulas include the contribution to the EPR parameters from both the spin-orbit coupling parameter of the 3d 7 ion and that of the ligand. From the calculations, the local atom-position parameters u (which are different from the corresponding values in the host crystals) for the Co 2+ impurity centers in both semiconductors are estimated. The results are discussed

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(NH 2 ) 3 ] + . The motional parameters of the two types of guanidinium cations have been determined. -PACS: 64.70K; 76.60.E

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 3p 3 D-3d 3 F o 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 · 10 23 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

We investigated Schottky barrier diodes of 9 metals (Mn, Cd, Al, Bi, Pb, Sn, Sb, Fe, and Ni) having different metal work functions to p-type Si using current-voltage characteristics. Most Schottky contacts show good characteristics with an ideality factor range from 1.057 to 1.831. Based on our measurements for p-type Si, the barrier heights and metal work functions show a linear relationship of current-voltage characteristics at room temperature with a slope (S=ϕ b /ϕ m ) of 0.162, even though the Fermi level is partially pinned. From this linear dependency, the density of interface states was determined to be about 4.5 · 10 13 1/eV per cm 2 , and the average pinning position of the Fermi level as 0.661 eV below the conduction band

Crystal field analysis of the energy level structure of the Cr 3+ ion in the Sc 2 O 3 crystal is performed, using the exchange charge model of the crystal field theory. The crystal field parameters acting on the optical electrons of the Cr 3+ ion at the sites with C 2 and C 3i symmetry are calculated from the crystal structure data. On the basis of the comparison between experimental absorption and emission spectra and theoretically calculated energy levels of Sc 2 O 3 :Cr 3+ , the conclusion is made that the spectroscopic properties of the title host are determined by the Cr 3+ ion at the positions of C 2 local symmetry. The Stokes shift S = 4.32 and the energy of the phonons effectively interacting with an impurity center h̅ω = 499 cm −1 are derived from the experimental spectra of absorption and emission

Eight 3-arylallyl alcohols were prepared, and their OH stretching frequencies were measured in twenty non-HBD solvents at room temperature. The observed stretching bands were highly sensitive to the nature of the solvents. Multiple parameter equations were applied to investigate the solvent effect on the O-H stretching frequency. The most significant solvent parameters were the nucleophilicity parameter and the Gutmann donor number, while the electrophilicity parameter was not significant

Fluorescence spectral features of PRODAN and LAURDAN in phospholipid vesicles of different phase states were investigated. The results indicate that in the liquid crystalline phase the dominant emission results from the charge transfer (CT) excited state, whereas in the gel state of the membrane the emission from the locally excited (LE) state dominates. The fluorescence time studies point out that there are two radiation modes, one starting from only vibrationally relaxed excited states S 1 (LE) ν ((S1(CT) ν ) and the other from a totally thermally equilibrated state S 1 (LE) EQ (S 1 (CT) EQ ). In accordance with the obtained decay time dependencies, the fluorescence emission from total nonequilibrated excited states consists of a dominant or minor radiation process in the LE or CT band emission

The local structure of molten CdCl 2 was investigated by X-ray absorption fine structure (XAFS) and X-ray diffraction(XRD) analyses. The nearest Cd 2+ -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 (CdCl 4 ) 2− is predominant in molten CdCl 2 . The XAFS result of a molten 50%CdCl 2 -KCl mixture shows that the 4-fold (CdCl 4 ) 2− structure holds also in the mixture

The heat capacity of solid and liquid LaBr 3 was measured by Differential Scanning Calorimetry (DSC) in the temperature range 300 - 1100 K. The obtained results were fitted by a polynomial temperature dependence. The enthalpy of fusion of LaBr 3 was also measured. By combination of these results with the literature data on the entropy, S 0 m (LaBr 3 , s, 298.15 K) and the standard molar enthalpy of formation, Δ form H 0 m (LaBr 3 , s, 298.15 K), the thermodynamic functions of lanthanum tribromide were calculated up to 1300 K

We investigate the effect of a transverse magnetic field on the unsteady flow of a generalized second grade fluid through a porous medium past an infinite flat plate. Using fractional partial differential equations, we are able to describe the velocity and stress fields of the flow. We also obtain exact analytic solutions of these differential equations in terms of the Fox’s H-function

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 NO 2 , CF 3 , CN, OH, NH 2 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 (NH 2 , OH, F) stabilize cyclobutanone, while electron withdrawing substituents (CF 3 , NO 2 ) 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

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-Cl 3 C 6 H 2 .NHCO.CH 2 Cl (N245TCPCA), N-chloro-N-(2,4,5-trichlorophenyl)-2-chloroacetamide, 2,4,5-Cl 3 C 6 H 2 .NClCO. CH 2 Cl (NC245TCPCA) and N-(2,4,5-trichlorophenyl)-2,2,2-trichloroacetamide, 2,4,5-Cl 3 C 6 H 2 . NHCO.CCl 3 (N245TCPTCA). The crystal type, space group, formula units and lattice constants in Å are: N245TCPCA: monoclinic, P2 1 /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, Pmc2 1 , 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

Semi-empirical AM1 SCF-MO calculations have been used to find the structure optimization and conformational interconversion pathways of a system containing a six-membered ring. The system has the two symmetrical energy-minimum conformations, chair and twist. The chair conformation has the most stable geometry. Some quantum parameters such as HOMO and LUMO energy, the chemical hardness and chemical potential are discussed

Policrystalline (bis)thiourea pyridinium bromide has been studied with dielectric spectroscopy and DSC method. New information about phase transitions in (bis)thiourea pyridinium bromide has been obtained and discussed. Two solid-solid phase transitions (at T 2 = 150 K - first order transition of order-disorder type, and T 1 = 180 K - second order) have been revealed. A change of the ion dynamics is observed at T 2

The eleven energetically lowest pure rotational transitions, J ←J−1 (J =1,2, . . . ,11), of H 13 CN, H 13 C 15 N, and HC 15 N in the ground and first excited bending state were measured. By operating the Cologne Tetrahertz Wave Spectrometer up to 1 THz in the sub-Doppler mode, a transition frequency accuracy of a few kHz is achieved. These measurements were carried out at frequencies between 80 - 950 GHz. In addition, some transitions of the three isotopomers with rotational quantum numbers J = 20,21,22,23 have been measured in Doppler-limited resolution near 2 THz, using the frequency stabilized Cologne Sideband Spectrometer for Terahertz Applications (COSSTA). Furthermore, direct l-type transitions of H 13 CN in the first excited bending state with J up to 35 have been measured. These new data are of particular importance, since we discovered highly excited circumstellar H 12 CN recently. A global fit of the newly enlarged data set together with existing carefully screened ro-vibrational data yields molecular constants which are highly reliable and of great importance both for astrophysical observations and laboratory applications

The second-order N-dimensional Schrödinger differential equation with the Coulomb potential is reduced to a firstorder differential equation by means of the Laplace transform and the exact bound state solutions are obtained. It is shown that this method solving the Schrödinger equation may serve as a substitute for the factorization approach also in lower dimensions. - PACS numbers: 03.65.Ge.

The mean amplitudes of vibration of the trans-IO 2 F 4 − anion have been calculated from known spectroscopic data between 0 and 1000 K. Bond peculiarities are discussed in comparison with those of trans-IO 2 F 5 2− and of some other structurally related species