Symmetry of the order parameter in the UGe2 superconductor

For the UGe₂ ferromagnetic superconductor, the forms of the order parameter are determined with allowance for the crystal symmetry and with the assumption that a strong spin-orbit interaction is present in the system. The limiting case corresponding to the immediate vicinity of the simultaneous transition to the superconducting and ferromagnetic phases is considered. The opposite limit corresponding to a wide separation of the Fermi surfaces with opposite spin orientations is considered as well. Possible effects of the ferromagnetic domain structure on the properties of UGe₂ in the superconducting state are discussed.     

Calculation of the vibronic transition moment when the geometries of the combining states of the molecules are significantly different

The concept of the adiabatic approximation is introduced from a few new standpoints, and the conditions are refined under which we can assume that the total energy of an electronic-vibrational (vibronic) state is the sum of the energies of the “electronic” and the “nuclear” problems and the wave function is represented as the product of the corresponding functions. An expression exactly corresponding to such an approximation is considered for the optical transition matrix element, and its individual terms are analyzed for any change in the geometric structure of the molecule upon optical excitation. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 290–293, May–June, 2006.     

Symmetries of the Fokker-Type Relativistic Mechanics in Various Forms of Dynamics

Abstract

The single-time nonlocal Lagrangians corresponding to the Fokker-type action integrals are obtained in arbitrary form of relativistic dynamics. The symmetry conditions for such Lagrangians under an arbitrary Lie group acting on the Minkowski space are formulated in various forms of dynamics. An explicit expression for the integrals of motion corresponding to the Poincaré invariance is derived.     

Theoretical determination of oscillator strengths for the principal series of rubidium-like ions by the Dirac-Fock method

A simple formula that allows the determination of the oscillator strengths for all transitions of principal series of the Rb-like ions is obtained from the relationship between the oscillator strengths and the corresponding photoionization cross sections. The photoionization cross sections are calculated by the Dirac-Fock method with allowance for the retardation and approximated by an analytic formula. The data for ten ions of the rubidium isoelectronic sequence (from Sr⁺ to Ag¹⁰⁺) are presented. Two types of gauges corresponding to the transition operators in length and velocity forms are considered.     

Self-consistent solutions of the problem of the interaction of a two-frequency field with a system of three-level atoms in the form of a phase-modulated simulton and a Raman soliton

This paper discusses features of the interaction of a system of three-level atoms with a bichromatic electromagnetic field. Steady-state solutions are found in the form of unimodal and nonunimodal solitary waves corresponding to a pair of pulses in the form of a simulton or a Raman soliton. An analytic form of the solutions is found, corresponding to a phase-modulated simulton and a Raman soliton. The conditions are determined for exciting them. The resulting solutions are of interest from the standpoint of the mechanism for forming the two-frequency coupled excitations observed in various experiments. Zh. éksp. Teor. Fiz. 113, 747–762 (February 1998)     

Investigating the dielectric properties of potassium iodate polycrystals

Linear and nonlinear dielectric properties of KIO₃ polycrystalline samples are investigated. It is shown that linear dielectric permittivity ε' displays four anomalies corresponding to phase transitions in KIO₃. Anomalies of third-harmonic coefficient γ_3ω are observed at temperatures of 113, 263, and 345 K, corresponding to phase transitions between KIO₃ ferroelectric phases. It is established that the third-harmonic coefficient responsible for the nonlinearity of dielectric properties displays no anomalies during the transition to the paraelectric phase of KIO₃ at approximately 485 K. Possible reasons for there being no such anomaly are discussed.     

北极冰-水耦合系统中声波传播特性

利用固体和流体介质中波传播理论,导出了冰-水两层复合结构中导波频散方程.进一步,利用二分法对频散方程进行了数值求解,得到了 w-k频散曲线(w与k分别为圆频率和波数),以及相速度和群速度频散曲线.结果表明:冰-水两层复合结构中导波由具有相同厚度水层和冰层中导波耦合而成,但与水层和冰层中导波频散曲线相比,复合结构中导波频...     

Potentials reducing the one-dimensional Schrödinger equation to the Mathieu equation

Potentials and the corresponding transformations reducing the Schrödinger equation to the Mathieu equation are presented. Solutions for Schrödinger equation corresponding to the given potentials are considered as well as the allowed energy values.Tomsk State Pedagogical Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 72–75, June, 1994.     

Solution of the level of approximation analytic formula of hydrogen-like atom for the Debye shielding potential by means of the power series

The first-order revision and the approximation analytical formula of the energy levels for hydrogen-like atoms in condition of the Debye shielding potential are achieved by means of the Rayleigh Schrdinger perturbation theory and the power series;meanwhile,the corresponding recurrence relations are got with the use of the solution of power series.Basic on mentioned above and with the use of energy consistent method,the equivalent value of second-order revision in condition of the Debye shielding potential as well be got and the result is compared with the data obtained by the numerical method.Beside,the critical bond-state and corresponding cut off of conditions are discussed.     

Diagonal structure of the S-matrix in the lee model

The diagonal structure of the S-matrix in the Lee model is studied. The N2θ- and N3θ-type eigenvalues are shown to factor exactly into the products of the corresponding Nθ eigenvalues, and it follows that these eigenvalues are free of production thresholds. The (implicit) eigenvalue equation for the V2θ-type eigenvalue is given, and this eigenvalue is shown to factor asymptotically into the product of the corresponding Vθ eigenvalues. These properties are conjectured to hold for Njθ- and Vjθ-type eigenvalues. It is conjectured that the two-body type eigenphase operator gives the dominant contribution to the S-matrix at high energy.     

Solution of the level of approximation analytic formula of hydrogen-like atom for the Debye shielding potential by means of the power series

The first-order revision and the approximation analytical formula of the energy levels for hydrogen-like atoms in condition of the Debye shielding potential are achieved by means of the Rayleigh Schrodinger perturbation theory and the power series;meanwhile,the corresponding recurrence relations are got with the use of the solution of power series. Basic on mentioned above and with the use of energy consistent method, the equivalent value of second-order revision in condition of the Debye shielding potential as well be got and the result is compared with the data obtained by the numerical method. Beside, the critical bond-state and corresponding cut off of conditions are discussed.     

Quark sea structure functions of the nucleon in a statistical model

Within a statistical model of linear confined quarks we obtain the flavor asymmetry and corresponding structure function of the nucleon. The model parameters are fixed by the experimental available data. The temperature parameter is adjusted by the Gottfried sum rule violation and the chemical potentials by the corresponding up (u) and down (d) quark normalizations in the nucleon. The light antiquark and quark distributions in the proton, given by d̄/ū, d/u and d̄-ū, as well as the neutron to proton ratio of the structure functions, extracted from the experimental data, are well fitted by the model. As the quark-confining strengths should be flavor dependent, a mechanism is introduced in the model to adjust the corresponding distribution, in order to improve the comparison obtained for the sea-quark asymmetries in the nucleon with the available experimental analysis. PACS  11.30.Hv; 14.20.Dh; 12.39.Ki; 12.40.Ee; 11.55.Hx     

Anomalous conversion in the decay of197mHg

The total andK-shell conversion coefficients of the 165 keV transition in the decay of^197mHg are determined from intensity balance considerations and a coincidence technique using a Ge(Li)—NaI (Tl) system respectively. The resultant values area _T =274.8±19.2 anda _K =47±12, whil the corresponding theoretical values are 344 and 77 respectively, indicating anomalous conversion. The gamma ray transition probability however, shows a hindrance of only about 6 and cannot be correlated with the present anomalous conversion data. TheK/L ratio of the 130 keV transition, determined using a summing method with a Ge(Li) detector, yielded 0.090±0.012, while the corresponding theoretical value is 0.048, indicating anomalous conversion. The corresponding gamma transition probability shows a hindrance of about 3000, in correlation with anomalous conversion.     

Dynamical entanglement as a signature of chaos in the semiclassical limit

The relationship between classically chaotic dynamics and the entanglement properties of the corresponding quantum system is examined in the semiclassical limit. Numerical results are computed for a modified kicked top, keeping the classical dynamics constant while investigating the entanglement for several versions of the corresponding quantum system characterized by a different value of the effective Planck constant ℏ _eff. Our findings indicate that as ℏ _eff → 0, the apparent signatures of classical chaos in the entanglement properties, such as characteristic oscillations in the time-dependence of the linear entropy, can also be obtained in the regular regime. These results suggest that entanglement is not a universal marker of chaotic dynamics of the corresponding classical system.     

Rotation Part of the Dielectric Permittivity of Water Vapor for Different Spectral Line Profiles

We estimate the possible influence of spectral line profile (Lorentz profile, Van Vleck–Weisskopf profile, and profile obtained by solving kinetic equation) on the rotation part of the dielectric permittivity of water-vapor monomers. Spectral regions corresponding to long-wavelength (static) and high-frequency (optical) limiting cases as well as regions in close proximity to resonances of various intensities are considered. The studied effects are compared with the corresponding effects on water-vapor absorption coefficient, which are related to factors determining the line-shape structure.     

The time evolution of the sol-gel process:29Si NMR study of the hydrolysis and condensation reactions of tetraethoxysilane

The structure and properties of the glass products prepared by the sol-gel process are strongly dependent on the experimental conditions of their preparation. The time dependence of the structural intermediate formation obtained during hydrolysis and condensation reactions in tetraethoxysilane, ethanol, H₂O, HCl (molar ratio 1:3:1.5:0.01) sol-gel reaction mixture was investigated with²⁹Si nuclear magnetic resonance spectroscopy at −75°C. It is clear that the substitution of the Si ethoxy group (OCH₂CH₃) by a hydroxyl (OH) shifts the resonance lines downfield. The dimer peaks are located about 9–10 ppm upfield from the corresponding monomers, and Si located in the middle of the trimers appeared at the chemical shift of 18–19 ppm from the corresponding monomers. The peaks of cyclic trimers, cyclic tetramers and the other higher oligomers are relatively broad and weak and exhibit a multiplet structure. The time dependence of the concentrations of the individual types of silicon in the reaction mixture was evaluated from the integral intensity of the corresponding Si atoms from the²⁹Si NMR spectra. The results obtained represent an input data to the various kinetic models of the complicated hydrolysis and condensation reactions.     

Solution of the Energy Level of Hydrogen-Like Atom for the Debye Shielding Potential

The first-order revision and the approximation analytical formula of the energy levels for hydrogen-likeatoms under the condition of Debye shielding potential are achieved by means of the Rayleigh-Schrodinger perturbationtheory; meanwhile, the corresponding recurrence relations are obtained from the use of the solution of power series. Basedon the above solutions and with the use of energy consistent method the equivalent value of second-order reversion underthe condition of Debye shielding potential is produced as well and the result is compared with the data obtained by thenumerical method. Besides, the critical bond-state and corresponding cut-off conditions are discussed.     

The normalization of the muon-decay current

A normalization condition for the muon decay current in V-A theory with radiative corrections included is obtained by the requirement that the generalized charges corresponding to the constituents of the current should fulfil an appropriate charge algebra. It is shown that the radiative corrections in second order are uniquely fixed by this requirement. The calculation is performed without the use of a cut-off. If the corresponding current algebra is postulated, the currents which, according to Adler, describe scattering of neutrinos on charged leptons, are completely determined. It is pointed out that Adler's Lagrangian for this process must be reduced with a factor $\text{1}\text{2}$ in order to make leptonic spin symmetric the whole interaction Lagrangian for leptonic processes.     

On the presence of oscillation in the V-I curve of type II superconductors relationship to the flux-flow noise voltage

The recently observed oscillations on the V-I curves in the vicinity of fields corresponding to the peak in I_c are suggested to be flux-flow noise voltages usually observed in type II superconductors and should be analyzed accordingly.     

Relativistic versus nonrelativistic solution of the N-fermion problem in a hyperradius-confining potential

We investigate the quantum system of N identical fermions in the relativistic limit. In this article the considered potential is a combination of Coulombic, linear confining and harmonic oscillator terms. By using Jacobi coordinates and introducing the hyperradius quantity we obtain the wave functions of the system as well as the corresponding energy eigenvalues. Assuming that all particles are confined within a hypersphere we calculate the corresponding x _bag . In particular we consider the case N = 3 which corresponds to baryonic systems. By using the experimental values of the charge radius of each baryon we calculate the potential coefficients. Within our treatment the results of the MIT bag model are recovered for N = 1. Finally we compare the results obtained by the Dirac equation with the corresponding results of the Schrödinger equation and we find that the energy spectra obtained by the former are much closer to experimental values.