2304-9782, 2618-8686, 2405-7223 14 4 2021 1-220

RAR RUS 9-20 Peter the Great St. Petersburg Polytechnic University Rul' Nikolai rul.nickolai@mail.ru Peter the Great St. Petersburg Polytechnic University Golovin Pavel yellowcat0101@gmail.com Ioffe Institute of the Russian Academy of Sciences Bagraev Nikolai bagraev@mail.ioffe.ru Ioffe Institute of the Russian Academy of Sciences Klyachkin L.E. klyachkin@mail.ioffe.ru Ioffe Institute of the Russian Academy of Sciences Malyarenko Anna annamalyarenko@mail.ru Optical-electric phase characteristics of silicon negative-U nanosandwiches In order to determine the possibility of the phase control of terahertz (THz) radiation from silicon negative-U nanosandwich structures (NSS), as well as to describe the relationship of optical and electrical characteristics of these NSS, the room-temperature measurement of modulated electroluminescence spectra have been carried out. In so doing, the opportunity to adjust a frequency, an amplitude and a phase of THz radiation was found; the longitudinal conductance phase characteristics of the edge channels of the NSS were recorded at high temperature (up to room one). The physical processes underlying the observed phenomena were analyzed. The edge channels’ cooling effect as a contributory factor for observation of the high-temperature macroscopic quantum phenomena arised due to the strong exchange interaction between the charge carriers in the edge channels and the dipole boron centers with negative correlation energy (negative-U reaction). The explanation of the observed phenomena using the quantum Faraday effect made it possible to apply the NSS as a component base for the silicon radiophotonics. 10.18721/JPM.14401 538.95 silicon nanosandwich negative correlation energy dipole boron centers terahertz radiation https://physmath.spbstu.ru/article/2021.54.1/ 01_9-20_14(4)2021.pdf

RAR RUS 21-39 Peter the Great St. Petersburg Polytechnic University Gasumyants Vitaly vgas@rphf.spbstu.ru Comparative study and analysis of the thermopower and the Nernst coefficient in the Y0,85Ca0,15Ba2-xLaxCu3Oy and Y0,85–xCa0,15PrxBa2Cu3Oy systems In this paper, we present the experimental results on the modification of the temperature dependences of the thermopower and the Nernst coefficient in a high-temperature superconductor of the Y0.85Ca0.15Ba2Cu3Oy composition under lanthanum and praseodymium doping. We have revealed specific features of the studied impurities influence in comparison with cases of single doping which are resulted from the presence of calcium ions in the lattice. The joint quantitative analysis of the experimental temperature dependences of the transport coefficients was performed, and this allowed us to determine the values of the main energy spectrum and charge-carrier system parameters in the studied samples. We analyzed the reasons for changes in the nature of the lanthanum and praseodymium influence induced by the calcium ions’ presence in the lattice and showed that they were different. The results obtained for the modification of the energy spectrum structure under doping allowed us to explain the peculiarities of the concentration dependences of the critical temperature in the systems under study. 10.18721/JPM.14402 538.935 high-temperature superconductor doping effect critical temperature thermopower Nernst coefficient energy spectrum https://physmath.spbstu.ru/article/2021.54.2/ 02_21-39_14(4)2021.pdf

RAR RUS 40-49 Military Space Academy named after A.F. Mozhaysky Sadin Dmitriy sadin@yandex.ru Numerical and analytical study of gas suspension expansion in a closed shock tube The expansion problem of ideal gas and incompressible spherical monodisperse particles mixture in a closed shock tube has been posed and solved. An asymptotically accurate solution of the initial (self-similar) stage of expansion of the gas suspension with a fine powder fraction was obtained. For the nonequilibrium case of larger particles, the problem was solved numerically by the hybrid large-particle method of the second-order approximation in space and time. The double-speed splitting effects of the flow stratification and the interface both into the gas-phase contact and the porosity jump as well as the interaction of the reflected shock wave with them were revealed. For the late stage of expansion, the dynamics of the gas suspension layer was established to be similar to a nonlinear oscillatory dissipative system with attenuation and a drift of the split contact interfaces depending on the size of dispersed inclusions. 10.18721/JPM.14403 532.529 gas suspension expansion closed shock tube self-similar solution oscillatory dissipative system hybrid large-particle method https://physmath.spbstu.ru/article/2021.54.3/ 03_40-49_14(4)2021.pdf

RAR RUS 50-68 Peter the Great St. Petersburg Polytechnic University Kalyuzhnyuk Alexander kalyuzhnyuk_av@spbstu.ru 57034855700 0000-0002-4088-4707 Peter the Great St. Petersburg Polytechnic University Antonov Valerii hmath@spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Modeling of nonstationary filtration in reservoirs with natural fractal fractures The article discusses a problem of naturally fractured reservoir modeling because some reservoirs exhibit the flow processes characterized by anomalous kinetics that do not obey Gaussian statistics. For this reason, the classical approach to the well test interpretation, its generalizations, and their transformation to a more complex model taking into account the fractal structure of fracture networks have been considered. The obtained results indicated the validity of the application of the fractal model to the interpretation of the well-test data where a power-law time dependence of the producing bottom-hole pressure was observed. Moreover, some symptoms were formulated whereby someone could identify the fractal well-stream behavior using the well-test data. Finally, the main issues for further studies the authors refer to the determination of the fractal parameters and the fractal model validation in laboratory experiments. 10.18721/JPM.14404 51-74, 553.98, 532.5 permeability power law fractured reservoir anomalous diffusion fractal dimension https://physmath.spbstu.ru/article/2021.54.4/ 04_50-68_14(4)2021.pdf

RAR RUS 69-83 Ioffe Physical-Technical Institute of the Russian Academy of Sciences Kovalenko Anatoliy ras-kan@mail.ru NRC «Kurchatov Institute» – PNPI Koptyuhov Artem t44h@yandex.ru

Gatchina of Leningrad region, Russian Federation

Peter the Great St. Petersburg Polytechnic University Meshcheryakov Dmitry fess_i@bk.ru JSC “Atomproekt”; Schuklinov Alexey mupol@mail.ru Thermokinetic processes in the corium traps of high-temperature melt during the reactor accidents at an A-plant: advanced three-stage 3D simulation This study continues a series of the works on the development of the model (proposed by us) which describes the changes in the thermal and phase states of a high-temperature core melt in the cooled under-reactor crucible-type trap when the melt interacting with sacrificial material in severe reactor accidents at nuclear power plants. On the basis of the generalized formulation of the Stefan problem with free interfaces, an extended three-stage 3D model of the proceeding processes has been proposed, that takes into account the influence of various factors. The model includes a stage of inversion of oxide and metal components changing in the corium basin during thermochemical reactions. Approbation of the model was carried out by comparison between the obtained results and the data of the full-scale COPRA experiment on the heat transfer by natural convection in a corium basin with an internal heat source. Our calculation results using the COMSOL Multiphysics software package confirmed the efficiency of the proposed scheme for arrangement of the sacrificial material in the trap, as well the scheme for the trap’s cooling to provide the required target functions. 10.18721/JPM.14405 53.072; 53:004 melt active zone subreactor crucible trap sacrificial material thermal state https://physmath.spbstu.ru/article/2021.54.5/ 05_69-83_14(4)2021.pdf

RAR RUS 84-94 Peter the Great St. Petersburg Polytechnic University Feklistov Efrem efrem.feklistov@mail.ru Development of the portable cold plasma source for biomedical applications A cold plasma source (CPS) developed by us has been put forward. The operating principle of the device is based on the use of a pulsed positive corona discharge at atmospheric pressure. The CPS exhibits compactness and autonomy. Particularly, the weight of the handheld plasma source is 80 g with the mass of the portable battery pack not exceeding 100 g. The electrical characteristics of electrode systems designed for direct and indirect treatment of biomedical objects with cold plasma were investigated. It was shown that in the studied electrode gaps the discharge exists in a streamer mode characterized by repetitive nanosecond current pulses in the range of 10 – 80 mA at operating voltages up to 10 kV. It was found that for the electrode system developed for indirect generation of cold plasma, the voltage range corresponding to stable discharge is wider than that for the system designed for the direct one. 10.18721/JPM.14406 537.523.3 cold plasma source corona discharge streamer discharge electrode systems biomedicine https://physmath.spbstu.ru/article/2021.54.6/ 06_84-94_14(4)2021.pdf

RAR RUS 95-113 Alferov University Scherbak Sergey sergeygtn@yandex.ru Alferov University Reshetov Ilya reshetov_iv@spbstu.ru Peter the Great St. Petersburg Polytechnic University Zhurikhina Valentina zhurikhina@mail.edu.ioffe.ru Alferov University Lipovskii Andrey lipovskii@mail.ru Second harmonic generation by surface of poled glasses: modeling and measurement of Maker fringes This paper presents a detailed theoretical analysis of the phenomenon of the second optical harmonic generation by two surfaces of a transparent isotropic glass plate. The dependence of intensity of the second harmonic wave generated by thermally-poled soda-lime glass plate on the incidence angle of fundamental wave (Maker fringes) has been measured. The obtained results of the modeling and the experiment were compared qualitatively and quantitatively. The comparison showed that thermal poling significantly increased quadratic nonlinear susceptibility χ of the subsurface region of the poled glass. We estimated this relative increase and obtained the following: χzzz, χzxx, χxzx increased about 6, 9 and 19 times respectively. 10.18721/JPM.14407 53.097 nonlinear optics second harmonic generation poled glass Maker fringe https://physmath.spbstu.ru/article/2021.54.7/ 07_95-113_14(4)2021.pdf

RAR RUS 114-125 Peter the Great St. Petersburg Polytechnic University Udovenko Stanislav udovenko_sa@spbstu.ru Ioffe Physical Technical Institute of the Russian Academy of Sciences Naberezhnov Alexander alex.nabereznov@mail.ioffe.ru Ioffe Physical Technical Institute of the Russian Academy of Sciences Borisov Sergey sergey.borisov@mail.ioffe.ru

Russia, 194021, St.Petersburg, Polytechnicheskaya, 26

Ioffe Institute of RAS Sysoeva Anna annasysoeva07@mail.ru Ioffe Institute of RAS Tomkovich Maria marya.tom83@gmail.com Joint Institute for Nuclear Research Islamov Akhmed islamov@nf.jinr.ru

Dubna, Moscow Region, Russia

Joint Institute for Nuclear Research Kuklin Alexander alexander.iv.kuklin@gmail.com

Dubna, Moscow Region, Russia

Structure characteristics of nanoporous glass with the carbon-modified interface Samples of porous matrices with the surface of channels (pores) modified with carbon were prepared on the basis of nanoporous sodium borosilicate glasses (SBS) with average pore diameter of 6 ± 0.5 (PG6) nm. A procedure has been developed for introduction of carbon into the PG6 channels from an aqueous solution of sucrose with its subsequent thermal decomposition. X-ray diffraction studies of the state of carbon in the pores of the obtained modified matrix have been carried out. The small-angle neutron scattering method is used for study of internal spatial arrangement of these matrices and to obtain information concerning to the state of channel surfaces in these samples. A combined analysis of the data obtained by X-ray diffraction and from the results of small-angle neutron scattering have shown that the process of thermal decomposition of sucrose in the channels led to the formation of amorphous carbo layers on the internal surface of the channels (pores) in these glasses, i.e. the "matrix-porous space" interface was being modified. 10.18721/JPM.14408 538.971, 539.26 nanoporous borosilicate glasses modification of interface small angle neutron scattering X-ray diffraction https://physmath.spbstu.ru/article/2021.54.8/ 08_114-125_14(4)2021.pdf

RAR RUS 126-134 Herzen State Pedagogical University of Russia Castro Arata Rene recastro@mail.ru Herzen State Pedagogical University of Russia Lapatin Nikolay NICOLJAPAT@mail.ru 0000-0001-9604-4769 Herzen State Pedagogical University of Russia Karulina Elena karulina@mail.ru Herzen State Pedagogical University of Russia Reztsov Tikhon sunnyundeadjuvati@icloud.com Polarizing properties of perfluorosulfonic membranes modified with terbium In order to determine the features of polarization and structural properties of perfluorosulfone membranes after their modification with Tb, MF-4SK membranes have been prepared and studied. The sorption properties of membranes were investigated by recording their optical absorption and transmission spectra in the visible and UV ranges in dynamics, as well as infrared reflection spectra. The temperature-frequency dependences of the main dielectric parameters of the objects under study, their spectra of complex conductivity were recorded and analyzed. As a result, it was found that the specific conductivity of terbium-modified perfluorosulfone membranes obeyed a power law. The presence of critical temperature of the system’s transition from semiconductor conductivity to metallic one was revealed. A scheme for the ion-exchange mechanism of the sorption fixation of terbium ions in the membrane was put forward. 10.18721/JPM.14409 53.08,538.9,539.23 сomposite material perfluorosulfonic membrane modification sorption polarization and structural properties https://physmath.spbstu.ru/article/2021.54.9/ 09_126-134_14(4)2021.pdf

RAR RUS 135-146 Peter the Great St. Petersburg Polytechnic University Baranov Maksim baranovma1993@gmail.com Peter the Great St. Petersburg Polytechnic University Tsybin Oleg otsybin@rphf.spbstu.ru Peter the Great St. Petersburg Polytechnic University Velichko Elena velichko-spbstu@ya.ru Free energy relaxation of glycine, tryptophan and albumin molecules in the ionized aqueous solution: Computer analysis A comparative analysis of the free energy of alanine, tryptophan and albumin protein amino acids in the aqueous solutions of sodium chloride with different concentrations (ionization degree) has been carried out using the molecular computer modeling method. Some dependences of dynamic scenarios of the behavior of the mentioned energy on the concentration of ionizing reagent (the dissociating salt) in the solutions were obtained. Such information can be applied when designing the hybrid micro and nanoelectronic devices with built-in biomolecular objects, e. g. biochemical sensors, devices with microflow of liquids, for the molecular film preparation technology, etc. 10.18721/JPM.14410 53.093, 53.096, 57.031, 57.033, 57.038 proteins peptides hybrid biomolecular electronics computer modeling https://physmath.spbstu.ru/article/2021.54.10/ 10_135-146_14(4)2021.pdf

RAR RUS 147-157 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

Antenna arrays based on Golomb rulers made of copper and superconducting elements The features of the amplitude behavior of the electromagnetic waves (the profile of a standing wave) reflected by antenna arrays have been studied. These arrays are Golomb rulers of different orders made of copper and HTSC structures. The dependences of the amplitude on the array’s arrangement with respect to the excitation source and the receiving device, as well as on the temperature. An analysis of obtained results revealed no dips in the standing wave amplitude profile for the 3rd and 4th order Golomb rulers. It was shown that for the Golomb rulers based on HTSC structures, an observed increase in the amplitude of the received signal on their cooling was associated with the transition to the superconducting state. 10.18721/JPM.14411 621.396.67 Golomb ruler antenna array nanostructure high temperature superconductor https://physmath.spbstu.ru/article/2021.54.11/ 11_147-157_14(4)2021.pdf

RAR RUS 158-171 Peter the Great St. Petersburg Polytechnic University Ushakov Nikolai n.ushakoff@spbstu.ru Peter the Great St. Petersburg Polytechnic Universit Semina Ekaterina feanaara@gmail.com Peter the Great St. Petersburg Polytechnic University Markvart Aleksandr markvart_aa@spbstu.ru 0000-0001-5988-1429 Peter the Great St. Petersburg Polytechnic University Liokumovich Leonid leonid@spbstu.ru The influence of human arterial network's frequency characteristics on a pulse wave delay estimation The article has examined the influence of frequency-dependent properties of a human arterial network on the distortion of a pulse wave (PW) signal and a resulting temporary displacement of the slope and systolic peak of the PW signal. When analyzing the operation of a cardiovascular system, a section of the arterial network was simulated by an equivalent RC circuit being a low-pass filter. As a result of the simulation, analytical expressions were obtained that allowed to determine the time of the PW signal propagation from a heart to a measuring point. The correctness of the expressions obtained was confirmed by numerical simulation and experimental measurements. 10.18721/JPM.14412 612.15 pulse wave transfer function cardiovascular system pulse wave delay https://physmath.spbstu.ru/article/2021.54.12/ 12_158-171_14(4)2021.pdf

RAR RUS 172-189 Peter the Great St. Petersburg Polytechnic University Markvart Aleksandr markvart_aa@spbstu.ru 0000-0001-5988-1429 Peter the Great St. Petersburg Polytechnic University Liokumovich Leonid leonid@spbstu.ru Peter the Great St. Petersburg Polytechnic University Ushakov Nikolai n.ushakoff@spbstu.ru Estimating the measurement resolution of an arbitrary finesse fiber-optic Fabry – Perot interferometer via Cramer – Rao bound The work is devoted to obtaining an analytical ratio for estimating the resolution of measurements using a fiber-optic Fabry – Perot interferometer with an arbitrary mirrors’ reflectivity and its spectral interrogation. For this purpose, we used the Rao – Cramer formalism. The corresponding analytical expression was first obtained under the assumption that there was no light divergence in the interferometer gap, and then the divergence was taken into account by introducing the effective reflection coefficient of the second mirror. Сharacteristics of the latter we found numerically for a wide range of interferometer parameters. The found relation connects the root-mean-square deviation of the measured values of the interferometer gap with the level of additive noise of the spectral signal of the interferometer and makes it possible to find the optimal parameters of the interferometer that provide the best resolution. Also, expressions for the mean level and standard deviation of the fiber-optic Fabry – Perot interferometer reflectivity characteristic were obtained. 10.18721/JPM.14413 535.3, 535-15, 535.417 Fabry – Perot interferometer fiber-optic resolution Cramer – Rao bound divergence https://physmath.spbstu.ru/article/2021.54.13/ 13_172-189_14(4)2021.pdf

RAR RUS 190-201 Peter the Great St. Petersburg Polytechnic University Pavlov Alexander a.pavlov@physics.spbstu.ru MBN Research Center at Frankfurt Innovation Center of Biotechnology Korol Andrei korol@mbnexplorer.com

Frankfurt am Main, Germany

M-5766-2013 57192222016 0000-0002-3584-4583 Peter the Great St. Petersburg Polytechnic University Ivanov Vadim ivanov_vk@spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

7003387326 0000-0003-1602-6144 MBN Research Center at Frankfurt Innovation Center of Biotechnology Solov'yov Andrei solovyov@mbnresearch.com

3 Altenhöferallee, Frankfurt am Main, 60438, Germany

Channeling and radiation of electrons and positrons in the diamond heterocrystals We analyze numerically the radiative and channeling properties of ultra-relativistic electrons and positrons propagating through a periodically bent diamond crystal grown on a straight single-crystal diamond substrate. Such systems are called heterocrystals being one of the experimentally realized specimens for the implementation of crystalline undulators. We state that in such systems the channeling and radiative properties of projectiles are sensitive to the projectiles' energy and to the beam propagation direction, e. g., to the beam-to-crystal site of entry: from the side of substrate or from that of periodically bent crystal. The results obtained are important for designing and practicing the new crystalline undulators. 10.18721/JPM.14414 538.911; 539.1.03 periodically bent diamond crystal channeling ultra-relativistic particle channeling radiation https://physmath.spbstu.ru/article/2021.54.14/ 14_190-201_14(4)2021.pdf

RAR RUS 202-217 St. Petersburg Federal Research Center of the Russian Academy of Sciences Stoliarova Valeriia vfs@dscs.pro St. Petersburg State University Tulupyev Alexander alt@dscs.pro Cox regression in the problem of risky behavior parameter estimation based on the last episodes’ data The article suggests an extension and refinement of the existing model for incomplete estimation of the person’s behavior characteristics using several last episodes of his risky behavior and including individual characteristics and other factors, in particular, the sex, age, etc. This extension has been made with a novel approach to formalization of the gamma Poisson model of behavior based on the random point process theory. The general form of the likelihood function for the estimates was derived. This formalization allowed to use the Cox regression model for the estimation of the process intensity parameters on the condition of only three last episodes taking into account different characteristics of the domain. The possibilities of the chosen approach were shown using the data on publication of posts in the online social media. 10.18721/JPM.14415 51-77:004.89+311.2 gamma Poisson model of behavior mixed Poisson process Cox regression online media user profiling https://physmath.spbstu.ru/article/2021.54.15/ 15_202-217_14(4)2021.pdf