2304-9782, 2618-8686, 2405-7223 11 4 2018 1-124

RAR RUS 7-14 Peter the Great St. Petersburg Polytechnic University Faradzheva Mislimat mpfaradzheva@physics.spbstu.ru

195251, St. Petersburg, Polytechnicheskaya St, 29

Peter the Great St. Petersburg Polytechnic University Prikhod’ko Aleksander aleks@physics.spbstu.ru

195251, St. Petersburg, Polytechnicheskaya St, 29

Ioffe Physical Technical Institute of the Russian Academy of Sciences Kon’kov Oleg oleg-l705@yandex.ru

194021, Politekchnicheskay st., Saint-Petersburg, 26

Conductivity features of the nanomodified HTSC structures The transport characteristics of nanostructures consisting of microcrystalline YBa2Cu3O7-δ powder and nanopowder of the same composition have been studied in the nanosecond duration interval of the pulse voltages applied to the nanostructure. An increase in the critical temperature Tc of the transition to the superconducting state was established to occur at the 20% nanopowder content. The obtained experimental data was interpreted in terms of the percolation theory. This theory holds that the optimal nanopowder content in the nanomodified material causes a rise of the maximum number of micropowder-nanopowder Josephson’s contacts. An increase in the structure porosity when the content falls off from the optimum, leads to a break-down of a percolation cluster and to a decrease in the Tc value; moreover, the temperature range where the transition to the superconducting state takes place, spreads. 10.18721/JPM.11401 538.945 nanostructure high-temperature superconductivity percolation cluster critical temperature https://physmath.spbstu.ru/article/2018.42.1/ 01_7-14_11(4)2018.pdf

RAR RUS 15-23 Institute of Geology of Karelian Research Centre, Russian Academy of Sciences Koval’chuk Anna eniaam@list.ru

Petrozavodsk, Russian Federation

Peter the Great St. Petersburg Polytechnic University Prikhod’ko Aleksander aleks@physics.spbstu.ru

195251, St. Petersburg, Polytechnicheskaya St, 29

The conductivity of the graphene-like carbon films: Anomaly in the 80–120 K temperature range The paper presents the results of conductivity studies in natural carbon films in the temperature range from 78 to 220 K. The data of structural studies using scanning electron microscopy and Raman spectroscopy are given. It has been found that the deposition of natural carbon on substrates with a conductive coating of indium oxide allows to obtain a new type of structure, that is, thin films, represented by homogeneous carbon nets, in the nodes of which there are globular nano-sized particles in the form of distorted graphene planes. The behavior of the current-voltage characteristics of carbon films containing graphene-like fragments was studied by nanosecond voltammetry. It was established that the sample resistance sharply increased and the sample diamagnetism exhibited (persisting for 50 thermal cycles) at the critical temperature. 10.18721/JPM.11402 538. 945+539. 216.2 graphene-like carbon thin film conductivity nanosecond voltammetry diamagnetism https://physmath.spbstu.ru/article/2018.42.2/ 02_15-23_11(4)2018.pdf

RAR RUS 24-34 Romanov Nikolay nikromanov.90@gmail.com Peter the Great St. Petersburg Polytechnic University Zakharova Irina zakharova@rhpf.spbstu.ru Peter the Great St. Petersburg Polytechnic University Malova Maria malovamm94@gmail.com

195251, St. Petersburg, Polytechnicheskaya St, 29

Elistratova Marina marina.elistratova@mail.ioffe.ru Peter the Great St. Petersburg Polytechnic University Musikhin Sergey musihin.sf@spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Effect of gamma radiation on the thin nanocomposite MEH-PPV/C60 films In this work, the effect of gamma radiation on the photoluminescent properties of thin films of binary nanocomposites MEH-PPV/C60 (polymer – fullerene C60) has been studied. Samples of pure MEH-PPV and MEH-PPV/C60 nanocomposites were synthesized in ratios of 9:1 and 3:1 on the mica and silicon substrates. Effect of type substrate on photoluminescence of pure thin films and nanocomposites were studied. Experimental data on dose dependences of the shape and intensity of the photoluminescence spectra after exposure of samples with doses up to 67 kGy were obtained and analyzed. The nonmonotonic nature of the change in the intensity of various spectral bands of the photoluminescence of nanocomposites with increasing dose and the absence of a shift of these bands was established. The obtained experimental results were interpreted from the standpoint of competition between the processes of crosslinking and breaking of polymer chains under the action of gamma irradiation. A practically important result of the study is the conclusion that MEH-PPV/C60 nanocomposites are highly resistant to gamma rays. 10.18721/JPM.11403 535.37, 538.958, 54-78 nanocomposite MEH-PPV C60 fullerene gamma radiation photoluminescence https://physmath.spbstu.ru/article/2018.42.3/ 03_24-34_11(4)2018.pdf

RAR RUS 35-46 Romanov Nikolay nikromanov.90@gmail.com Peter the Great St. Petersburg Polytechnic University Malova Maria malovamm94@gmail.com

195251, St. Petersburg, Polytechnicheskaya St, 29

Lähderanta Erkki Erkki.Lahderanta@lut.fi Peter the Great St. Petersburg Polytechnic University Musikhin Sergey musihin.sf@spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Effect of gamma radiation on luminescence and photoconductivity of MEH-PPV – lead sulfide nanocomposite The thin-film properties of polymeric nanocomposite MEH-PPV/PbS (with PbS quantum dots (QD)) and PbS-QD gamma-irradiated by 0.5–24.4 kGy doses have been studied. The film samples for photoluminescence (PL) investigation were prepared from solution using spin-coating technique, and for photoconductivity measuring were made using slot technique. The threshold doses for irreversible sharp PL-degradation of nanocomposite determined by the degradation of PbS-QD were found. The behavior dynamics of MEH-PPV/PbS photoconductivity after irradiation was analyzed. The conduction relaxation observed in the MEH-PPV/PbS was shown to be due to restoration of damages in the conjugate chains of the MEH-PPV polymer. Moreover, the absence of conductivity and photoconductivity relaxations in the colloidal PbS was revealed. 10.18721/JPM.11404 535.37 54-78 539.2 541.65/.654 gamma radiation photoluminescence photoconductivity quantum dot lead sulfide conducting polymer https://physmath.spbstu.ru/article/2018.42.4/ 04_35-46_11(4)2018.pdf

RAR RUS 47-60 Peter the Great St. Petersburg Polytechnic University Khrapunov Evgenii hrapunov.evgenii@yandex.ru

195251, St. Petersburg, Polytechnicheskaya St, 29

Peter the Great St. Petersburg Polytechnic University Chumakov Yuri chymakov@yahoo.com The structure of a natural convective flow over a horizontal heated disc at small Grashof numbers In the paper, the results of physical and numerical simulation of a natural convective flow formed over a heated horizontal disk with small Grashof numbers have been presented. The characteristics of the near-wall flow region and of the ascending flow one were considered in detail. On the basis of experimental and calculated data, the geometric flow characteristics, namely temperature and dynamic thicknesses, were determined. A good agreement between the experimental results and numerical simulation data was achieved. The results obtained were also compared with published data. The distribution of the vertical velocity component in the near-wall layer was determined. The analysis of the basic characteristics of heat exchange, namely the local and integral Nusselt numbers, was carried out. 10.18721/JPM.11405 532.5.013.13 natural convection natural convective plume flow structure physical experiment numerical simulation https://physmath.spbstu.ru/article/2018.42.5/ 05_47-60_11(4)2018.pdf

RAR RUS 61-76 Kazan (Volga region) Federal University, Kazan Karelin Dmitriy karelindl@mail.ru

Russian Federation

Kazan Federal University – Naberezhnye Chelny Institute Boldyrev Alexey alexeyboldyrev@mail.ru

Naberezhnye Chelny, Russian Federation

Kazan National Research Technical University named after A.N. Tupolev – KAI Gureev Viktor viktor.gureev@kai.ru

Kazan, Russian Federation

Kazan Federal University – Naberezhnye Chelny Institute Boldyrev Sergey underminder@mail.ru

Naberezhnye Chelny, Russian Federation

Modeling of dynamic processes in the vapor compression cooling system In the paper, a dynamic model of a vapor compression cooling system is presented. In addition to the usual one, it takes into account the working agent’s masses in the heat exchangers, this agent’s vapor content behavior in time at the outlet of the expansion valve, and the whole spectrum of two-phase flow modes during the working agent’s evaporation. It was established that it took more time for temperature’s and mass flow’s (in a vapor compression cooling system) transitions to steady states than for the rotational speed of the compressor shaft. The connection between the negative dynamics of the evaporation temperature and the initial ambient temperature was shown. Moreover, it was the connection between the delay in stabilization of the mass flow of the working medium and the initial ambient temperature as well as the degree of a pressure increase in the thermodynamic cycle of the vapor compression cooling system. 10.18721/JPM.11406 51-73: 621.574 dynamic model vapor-compression cooling system heat transfer temperature difference compressor https://physmath.spbstu.ru/article/2018.42.6/ 06_61-76_11(4)2018.pdf

RAR RUS 77-84 0000-0001-5219-6744 Peter the Great St. Petersburg Polytechnic University Taradaev Evgeniy Sominski Gennadiy sominski@rphf.spbstu.ru Simulation of the electron-optical system with a field emitter for a short-wave diagnostic gyrotron The operational capability of multi-tip silicon emitters with protective metal fullerene coatings in a three-electrode electron-optical system (EOS) with magnetic confinement has been studied. This EOS is intended for electron-stream generation in the diagnostic shortwave gyrotron. Three-dimensional calculations were performed using the Comsol software package. The feasibility of attainment of currents beyond 20 – 30 mA required for the diagnostic gyratron operation was shown. In the course of the calculations, the ratio of the currents falling on the control electrode and on the collector was determined. In the absence of a magnetic field, the control electrode’s current was 0.5% of the cathode’s one. No control electrode’s current existed when the values of the magnetic field induction in the region between the cathode and the control electrode were beyond 0.07 T. 10.18721/JPM.11407 537.533.2 multi-tip field emitter electron gun magnetic tracking electron beam https://physmath.spbstu.ru/article/2018.42.7/ 07_77-84_11(4)2018.pdf

RAR RUS 85-94 Peter the Great St. Petersburg Polytechnic University Stepanov Vyacheslav vstepanov@phmf.spbstu.ru

195251, St. Petersburg, Polytechnicheskaya St, 29

PJSC “Power Machines” Petrenya Yuriy Petrenya_YK@power-m.ru

St. Petersburg, Russian Federation

PJSC “Power Machines” Andreev Alexander Andreev_am@power-m.ru

St. Petersburg, Russian Federation

PJSC “Power Machines” Kostelov Andrey Kostelov_AM@power-m.ru

St. Petersburg, Russian Federation

PJSC “Power Machines” Mannanov Emil Mannanov_ER@power-m.ru

St. Petersburg, Russian Federation

Talalov Victor vtalalov@phmf.spbstu.ru Effective heat conductivity of polymeric composite materials: The influence of component properties The goal of this study is to increase the effective heat conductivity (EHC) of the polymer composite materials. We have carried out numerical simulation of the polymer composite EHC when making microsized high-thermal conductivity fillers of various shape a component of the composite, and its volume fraction being varied форas well. The influence of particles’ thermal conductivity on the polymer composite materials’ EHC was analyzed. Recommended practice for the polymer composite EHC increasing was suggested. Shape changing, volume fraction optimization, the filler particles’, and the matrix’ thermal conductivity increasing was proposed. The calculation results were in good agreement with our experimental data and published in scientific literature. This study gave an insight into the function of high-thermal conductivity fillers on the EHC of the polymer composite materials. 10.18721/JPM.11408 536.21 numerical simulation composite material effective thermal conductivity high-thermal conductivity filler https://physmath.spbstu.ru/article/2018.42.8/ 08_85-94_11(4)2018.pdf

RAR RUS 95-103 Peter the Great St. Petersburg Polytechnic University Gorobei Natalia n.gorobey@mail.ru Peter the Great St. Petersburg Polytechnic University Luk'yanenko Alexander alex.lukyan@rambler.ru Internal time in relativistic quantum mechanics A formulation for spinless particles, that holds true the formal equivalency of spatial and time particle’s coordinates achieved through the introduction of an auxiliary parameter of evolution, has been put forward in terms of relativistic quantum mechanics. The proposed modification of theory gave a space-time picture of elementary processes involved in a finite region of the Minkowsky space in the form of scattering amplitudes. In order to define the evolution parameter, an additional condition was introduced. That was the presence of an extreme of the scattering amplitude phase. The probabilistic interpretation of the scattering amplitude includes a contraction of integration measure in the Minkowsky space on a 3D-surface given by experimental conditions. The nonrelativistic limit of the modified theory was shown to coincide with the Schröedinger theory, including the dynamical model of the stationary scattering problem in terms of wave packets movement. 10.18721/JPM.11409 530.12:517.988.38(075.8) Minkowsky space spinless particle wave packet internal time scattering amplitude https://physmath.spbstu.ru/article/2018.42.9/ 09_95-103_11(4)2018.pdf

UNK RUS 104-111 Peter the Great St. Petersburg Polytechnic University Larionov Nikolay larionov.nickolay@gmail.com Peter the Great St. Petersburg Polytechnic University Barantsev Konstantin kostmann@yandex.ru

195251, St. Petersburg, Polytechnicheskaya St, 29

Peter the Great St. Petersburg Polytechnic University Popov Evgeniy enp-tion@yandex.ru

195251, St. Petersburg, Polytechnicheskaya St, 29

Single-atom laser with a low-finesse cavity operating in the strong-coupling regime In this work, transition processes and a stationary regime of a single-atom laser with incoherent pumping under conditions of the strong-coupling and bad-cavity limit have been studied. In the thresholdless regime, our numerical results were compared with corresponding experimental data. The amplitude and the frequency of the relaxation oscillations as the functions of the incoherent pumping value were also analyzed. The pumping strength was established to have a very significant effect on the amplitude of these oscillations and no appreciable effect on their frequency. The possibility of the noise reduction by means of increasing of the number of atoms in the cavity was discussed. 10.18721/JPM.11410 535.3 single-atom laser strong-coupling regime thresholdless lasing relaxation oscillations https://physmath.spbstu.ru/article/2018.42.10/ 10_104-111_11(4)2018.pdf

RAR RUS 112-120 Voronezh State Technical University Golovinski Pavel golovinski@bk.ru

Voronezh, Russian Federation

Voronezh State Technical University Proskurin Dmitry pdk@vgasu.vrn.ru

Voronezh, Russian Federation

Wave scattering by an anisotropic two-scale rough surface The scalar-wave scattering by a rough anisotropic surface has been considered in the paper. In order to solve the problem, a two-scale model taking into account the wave scattering by coarse irregularities under the Kirchhoff’s approximation and determining that one by fine roughnesses through the Rayleigh method was used. The scattering cross section was averaged over the anisotropic distribution of the surface slopes. The results of numerical calculations of the total scattering cross section were presented. They demonstrate the anisotropy impact of the roughness distribution on the wave scattering indicatrix. 10.18721/JPM.11411 534.23; 535.36 scattering rough surface anisotropy Kirchhoff’s approximation two-scale model https://physmath.spbstu.ru/article/2018.42.11/ 11_112-120_11(4)2018.pdf