Vol 60, No 1 (2017)

High-resolution absorption spectrum of the rotational-vibrational 2ν₃ band of the S¹⁸O₂ molecule has been registered for the first time. An analysis of the band by the method of combination differences allows rotational-vibrational structure of the (v = 2, A₁) state to be determined. The inverse spectroscopic problem is solved based on the data obtained.

Results of spectral-luminescent and electroluminescent studies of organic semiconductor zinc complexes in light-emitting diode devices are presented. A displacement of the electroluminescence band maximum toward longer wavelengths with structure complication is shown. Devices based on zinc metal organic complexes have low threshold voltage (from 2.5 V) and brightness above 100 cd/m².

Bound states of relativistic systems of two particles are considered in the special case of an interaction operator which admits reduction of partial integral equations to differential equations directly in the momentum representation. Exact analytical solutions of these equations are obtained for some values of the energy (mass) of a system of two particles. Equations with other energies are solved numerically. Dependences of the mass spectra of two-particle systems and their wave functions on the parameters are found.

Within the framework of the modified potential cluster model with classification of the orbital states of nuclear particles according to Young tableaux and isospin, calculations of the astrophysical S-factor of the radiative p³H capture reaction at energies from 1 keV to 10 MeV are performed and the possibility of describing the available experimental data in the energy range from 50 keV to 5 MeV is demonstrated.

A method of numerical modeling is used to solve three most interesting problems of artificial Earth satellite (AES) dynamics. Orbital evolution of an ensemble of near-Earth objects at altitudes in the range from 1 500 to 60 000 km is considered, chaoticity of motion of objects in the geosynchronous zone is studied by the MEGNOanalysis, the parameters of AES motion are determined, and the models of forces are considered from measurements for GLONASS satellites. The recent versions of algorithms and programs used to perform investigations are briefly described.

The paper focuses on the study of structural features and electret properties of the fine-sized mineral kaolin. Special attention is paid to the mechanism of interphase interaction at the interface of electrically active heterogeneous media that leads to the emergence of internal self-electric field capable of ensuring the current circulation in such systems. The authors consider the possibility of regulating the processes of local change in the polar water structure under the impact of the self-electric field.

The paper focuses on the effect of a multilevel impurity in a graphene nanoribbon on the tunnel current flowing in the contact of the latter with metal. Calculations of the ballistic current in a graphene nanoribbon and the tunnel current of the ribbon contact with metal are performed. Analysis is provided for the dependence of current-voltage characteristic of the contact on the integral of transition between impurity levels of the nanoribbon.

The paper deals with ab initio investigations of elastic and photoelastic properties of oxides and nitrates of alkaline-earth metals. In gradient approximation of the density functional theory (DFT), these properties are studied with the use of the linear combination of the atomic orbital technique. DFT calculations are done with the CRYSTAL 14 software package. The paper introduces the elastic and photoelastic constants, anisotropy parameters for single-crystalline phases and the elastic modules, hardness, Poisson ratio for polycrystalline phases. Such parameters as sonic speed, Debye temperature, thermal conductivity, and Gruneisen parameter are estimated herein. For the fist time, mechanical stability, anisotropy of elastic and photoelastic properties and their dependences are investigated ab initio in this paper. Experimental results on elastic and photoelastic properties of oxides and nitrates are in good agreement with theoretical calculations.

The dependence of microstructure, microhardness, and strength properties in tensile strain tests of commercially pure aluminum on strain during accumulative roll-bonding was studied. The methods of transmission electron microscopy and electron back scattered diffraction patterns analysis were used to establish that a lamellar ultrafine structure is formed in aluminum after accumulative roll bonding. It is shown that aluminum microhardness, ultimate strength, and yield strength increase monotonically with the degree of true logarithmic strain increasing from 3.2 to 8.0. The reasons for the difference in the structure and mechanical properties of the aluminum studied from the ones relevant for the aluminum deformed by equal-channel angular pressing are discussed.

It is reported that irradiation of the film/substrate system (Zr–Ti–Cu)/(A7) with a high-intensity electron beam is followed by the formation of a multi-phase state, whose microhardness is approximately by a factor of 4.5 higher than that of the technical grade aluminum А7, which is due to the substrate structure grain refinement and precipitation of zirconium aluminides in the surface layer.

Based on the macroscopic theory of statistical systems with scalar interparticle interaction developed by one of the authors, numerical models of cosmological evolution of the multicomponent Boltzmann plasma with scalar charged particles without symmetry between particles and antiparticles are constructed and analyzed. The basic features of cosmological models in this class are elucidated, in particular, the possibility of sufficiently fast transitions to different modes of cosmological expansion is demonstrated.

An expression is obtained for the energy band bending eφ_sH on the surface of the SnO₂ film in the clean air + hydrogen mixture. It is assumed that the value of eφ_sH depends not only on the surface charge density of adsorbed oxygen ions O^¯, but also on the negative charged hydroxyl groups (OH^¯). The results of the analysis of the dependences of eφ_sH on the hydrogen concentration \( {\mathrm{n}}_{{\mathrm{H}}_2} \) and the absolute humidity of the gas mixture obtained during the operation of the sensor in the thermo-cyclic mode are presented. A method for the determining \( {\mathrm{n}}_{{\mathrm{H}}_2} \) in the examined gas mixture is proposed. The method based on the dependence of eφ_sH on the hydrogen concentration established during the calibration of the sensor is proposed. The dependences of the energy band bending on the SnO₂ surface at \( {\mathrm{n}}_{{\mathrm{H}}_2} \) = 0 and the conductivity of the sensor on its temperature during the heating period are discussed.

An approach to solving the problems on transmission of material particles (e.g., molecules) through composite complex-shape potential barriers is proposed. To this end, a novel computational technique for integrating the Schrödinger equation is developed, which is based on the use of a non-standard matrix-analysis procedure and shows a good promise of being generalized to include two- and three-dimensional wave-dynamics problems. A good agreement is demonstrated between the results obtained using this approach and exact solutions for the transmission coefficient of a rectangular barrier. In the cases of particles or energy waves penetrating composite potential barriers, a quantum character of the membrane penetrability increasing as a function of the particle or wave energy is revealed. It is found that for the particles or photons of certain energies their transmission ratio could be increased by a factor of 2 or 3 via the use of new energy barriers added to the membrane.

Quality of oral speech reproduction using stochastic digital systems of information transfer at its statistical compaction is analyzed (on the example of Russian and Kazakh speeches) with the ratio of the speech signal power to the digitization and restoration noise power taken as quantitative characteristic of speech description. From an analysis of the results obtained it unambiguously follows that for analytical determination of the quality of speech message restoration using stochastic digital transfer systems it is expedient not to resort to approximations, but to use for estimation the experimentally obtained distribution of the probability of the number of successively rejected counts. The preference of the approach with alternating priority is established for a Russian speech message. In consideration of the Kazakh speech, the preference of the approach with alternating priority of the message is revealed. The approach with priority alternation in a count is the best of the three approaches being considered (with fixed priority, priority alternation in the transfer cycle Е1 and priority alternation in a count) for messages of the oral Russian and Kazakh speeches. This significant preference is explained by the influence of successive losses of more than one count on the ratio of the signal to noise power.