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SIBERIAN JOURNAL OF PHYSICS. Scientific Journal. 2018. V13, i 2 |
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Radiophysics and Electronics |
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Muminov Kh. Kh., Shokirov F. Sh. Dynamics of the Interaction of Two-Dimensional Domain Walls with a Topological Vortex A numerical investigation of the dynamics of three-soliton interactions of 180-degree domain walls with a topological vortex (soliton) of the Belavin-Polyakov type in the phase space of a (2+1)- dimensional anisotropic O(3) invariant nonlinear sigma model is carried out. Models of interaction of topological structures of the kink-vortex-antikink type are obtained, where the annihilation of domain walls and complete decay of topological vortices onto localized perturbations that have a unit value of the Kronecker index are observed. It is established that in the case of the opposite direction of the field, the annihilating domain walls absorb some of the energy of the topological vortex equivalent to the unit value of the Kronecker index. In the case of domain walls of the same polarity, depending on the Bloch or Neel structure of the interphase boundaries, the process of their annihilation occurs, respectively, without absorbing the energy of the topological vortex or with energy absorption equivalent to the value of two units of the Kronecker index. Based on the methods of the theory of finite difference schemes and the application of the properties of stereographic projection, a complex program module is proposed that implements an algorithm for the numerical calculation of the evolution of three-soliton interactions in a stratified space. |
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Physics of a fluid, neutral and ionized gases |
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Kudashkin D. V., Salomatov V. V., Salomatov A. V. Installed Thermal Range of the Round Channel in the Conditions of Dielectric Heating Using the method of elementary thermal balances, theoretical dependences were constructed on
the calculation of the steady-state thermal conditions of a circular channel with a moving incompressible |
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Êîçëîâ Kozlov V. V., Grek G. R., Litvinenko Yu. A., Shmakov A. G., Vikhorev V. V. Diffusion Combustion of Plane Hydrogen Microjet Efflux from Slotted Micronozzle at Sub- and Supersonic Velocity The purpose of this work is experimental study of the plane hydrogen microjet diffusion combustion efflux from slotted micronozzle at sub - and supersonic velocity. As a result of these studies the following results are received. For the first time, four scenarios of the plane hydrogen microjet diffusion combustion, including supersonic combustion in the presence of supersonic cells as by air, and on hydrogen are found. It is shown that stabilization of subsonic combustion of the hydrogen microjet is connected with existence of «bottleneck flame region». On the other hand, stabilization of supersonic combustion of the hydrogen microjet is connected with existence of the supersonic cells. The hysteresis of the plane hydrogen microjet diffusion combustion depending on microjet ignition (near or far from a nozzle exit) and direction of its velocity efflux change (growth or reduction) is found. |
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Kozlov V. V., Grek G. R., Litvinenko Yu. A., Shmakov A. G., Vikhorev V. V. Diffusion Combustion of Hydrogen Round Microjet at Sub- and Supersonic Velocity Efflux from Nozzle The purpose of this work is experimental study of the round hydrogen jets diffusion combustion efflux from nozzles with different diameters of nozzle exit at sub- and supersonic velocity. As a result of the experimental studies the following results are received. Four scenarios of diffusion combustion of the hydrogen round microjets, including «supersonic burning» in the presence of supersonic cells as by air, and on hydrogen are for the first time submitted. It is found that stabilization of the hydrogen round microjet subsonic burning is connected with existence of «bottleneck flame region», and «supersonic burning» of a microjet with existence of supersonic cells. Hysteresis of the hydrogen round microjets diffusion combustion is connected with the microjet ignition method of (near or far from a nozzle exit) and directions of the velocity change of its efflux (growth or reduction) is found. It is shown that «supersonic diffusion combustion» of the hydrogen round microjets as by air, and to hydrogen, is implemented only in a situation of the micronozzle diameter size outlet lying in the range of 1 mm. |
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Ttufanov D. Yu., Zavjalov A. P., Zobov K. V., Syzrantsev V. V., Bardakhanov S. P. Analysis of Changes in the Elemental Impurity Composition in the Silica Nanopowder Synthesis by Electron Beam Evaporation The paper analyzes the changes in elemental impurity composition in the nanopowder synthesis by electron beam evaporation. The conditions in the zone of the initial material evaporation were evaluated. The theoretical justification of the method described of the conditions evaluation at evaporation of high-purity quartz sand in the process of silica nanopowder synthesis by electron beam evaporation. Estimated evaporation temperature due to change of the aluminum and titanium concentrations was 2493 K. The experimental measurement and comparison of the elemental impurity compositions of the vaporized material and the resulting nanopowder for two silica samples had been conducted. |
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Klementyeva I. B., Teplyakov I. O., Vinogradov D. A., Ivochkin Yu. P. Modes of Electrovortex Flows Forming in Hemispherical Geometry Results of the study of the vortex flows forming under the action of electromotive body force in the hemispherical volume filled with liquid metal are presented in the paper. Experimental setup for the investigations of the processes is described here. Numerical simulation based on magnetohydrodynamical and electrodynamical models are discussed. Several modes of the electrovortex flows observed in the system are considered. Velocity dependences on the values of electric current and external magnetic field are also constructed. |
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Solid-State and Semiconductor Physics, Physics of Nanostructures |
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Borisov G. M., Gol’dort V. G., Zhuravlev K. S., Kovalyov A. A., Kochubei S. A., Ledovskikh D. V., Malin T. V., Rubtsova N. N. Second Harmonic Generation in Al0.1Ga0.9N Thin Film Second harmonic of femtosecond laser Yb3+:KY(WO4)2 generated in transmission of thin film Al0.1Ga0.9N grown on sapphire monocrystal of (0001) orientation does not reveal any saturation up to infrared pumping intensity 200 MW/cm2. The p-polarized second harmonic radiation was detected both for p-polarized and s-polarized pumping radiation; the second harmonic signal is essentially lower in the second case. In both cases, the second harmonic signal is absent at normal incidence, and it reaches maximum value at incidence angle of about 50 degree with further decrease. Lateral non-homogeneity was detected at 5 % level; absence of azimuth dependence corresponding to sixth order symmetry axis is considered. |
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Sidorov N. V., Teplyakova N. A., Titov R. A., Palatnikov M. N. Structure Disorder and Optical Characteristics of Congruent Lithium Niobate Crystals Grown from Boron Doped Melts We have detected changes in the order of main cations and vacancies along the crystal polar axis and distortions of oxygen octahedra in lithium niobate crystals grown from congruent melt doped by non-metal boron. This was found due to concentration dependence of widths and intensities of Raman bands of the researched crystals. Boron was found to be absent from the crystal structure. The distortions of oxygen octahedra were demonstrated to be anisotropic. The distortion is connected with octahedra expansion along the polar axis. Nominally pure lithium niobate crystals grown from boron doped congruent melt are structurally uniform. The structure uniformity of such crystals is higher than the one of nominally pure congruent crystals. NbLi defects amount in such crystals is close to the amount in stoichiometric crystal. At the same time lithium niobate crystals grown from boron doped congruent melt possesses weaker photorefractive effect than the stoichiometric crystal. |
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Alikulov M. N. Influence of Impurity Centers and Recombination Processes on Photoelectricity of Photoelements The article deals with photoelectric phenomena in solar batteries, as well as the influence of impurity
atoms and recombination processes on the photosensitivity of photocells. Explained the relationship |
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Chemical, Biological and Medical Physics |
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Kruchinin N. Yu., Kucherenko M. G. Molecular Dynamics Simulation of Conformational Structures Polyampholytes on the Surface of Gold Nanoparticle Using molecular dynamics we studied the nature of the location polyampholytes on the surface of spherical gold nanoparticles, including adsorbed on the macrochain molecules of eosin. As a result of the molecular dynamics simulation, equilibrium conformational structures of polyampholyte polypeptides adsorbed on the surface of a spherical gold nanoparticle were obtained. A description is given of the radial distribution of the density of the links of a macromolecule adsorbed on the surface of a spherical nanoparticle on the basis of a special mathematical model of the conformational structure of a polymer created using the statistical theory of macromolecules. The dependences of the average radial concentration of atoms of polyampholyte polypeptides with differentiation by the types of links, as well as the eosin molecules adsorbed on the macrochain on a gold nanoparticle, are constructed. Approximating curves calculated on the basis of the statistical theory of macromolecules are given. The obtained results can be used to create nanosystems with a specified character of the arrangement of dye molecules, which can be used to create a luminescence-optical sensor of the concentration of molecular (including singlet) oxygen. |
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Kruchinina M. V., Kruchinin V. N., Volodin V. A., Prudnikova Ya. I., Gromov A. A. Spectroscopy of Combination Scattering of the Light for Blood Serum in Patients with Colorectal Cancer with Various Localization of Metastases (Pilot Study) The spectra of combination scattering of the light (Raman) for samples of liquid serum in 68 people were studied: 19 conditionally healthy persons without oncological pathology and 49 people with colorectal cancer (divided into 3 groups depending on the localization of metastases) with the goal of determining the possibility of using Raman-spectroscopy for liquid serum in differentiating patients with colorectal cancer (CRC) with a various localization of metastases. The intensity of the peaks at 1005, 1157 and 1520 cm–1 in Raman spectra in patients with CRC compared with healthy individuals turned out to be significantly lower, correlating with the stage of the disease and the presence of metastases, which makes it possible to treat serum by Raman-spectroscopy as a promising diagnostic approach in colorectal cancer, in including at the early stages of the development of the disease. The diagnostic accuracy of this method in performing ROC analysis in differentiating local-regional CRC from metastatic was AUC 0.91 (0.82; 0.95) (95 % confidence interval), in distinguishing patients with liver metastases from those extrahepatic – AUC 0.73. |
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