2304-9782, 2618-8686, 2405-7223 14 2 2021 1-148

RAR RUS 7-14 Blagoveschensk State Pedagogical University Baryshnikov Sergey svbar2003@list.ru Blagoveshchensk State Pedagogical University Milinskiy Alexey a.milinskiy@mail.ru Amur State University Stukova Elena lenast@bk.ru ANTONOV Anton antonov.lit@bgpu.ru Dielectric properties of (R)-3-quinuclidinol in the porous matrix of aluminum oxide The paper presents findings of an investigation into the linear and nonlinear dielectric properties of (R)-3-quinuclidinol embedded in porous aluminum oxide (pores of size 300 nm), in comparison with the properties of bulk (R)-3-quinuclidinol. A decrease in the Curie temperature in the nanocomposite, both upon heating and cooling, in comparison with a bulk sample is revealed. A decrease in the phase transition temperature allows for interpretation on the basis of the known theoretical models for ferroelectric small particles. 10.18721/JPM.14201 537.956 (R)-3-quinuclidinol aluminum oxide ferroelectric dielectric constant nanocomposite phase transition https://physmath.spbstu.ru/article/2021.52.1/ 01_7-15__14(2)2021.pdf

RAR RUS 16-27 Tomsk State University of Control Systems and Radioelectronics Mikhailov Mikhail membrana2010@mail.ru Alekseeva Olga blackhole2010@yandex.ru Tomsk State University of Control Systems and Radioelectronics Yuryev Semen semyon.yuryev@tusur.ru Phase transitions and diffuse reflectance spectra of barium titanate-zirconate solid solutions The composition, structure, particle size distribution, diffuse reflectance spectra, integral absorption coefficients of solar radiation and dielectric properties of BaTi(1–x)Zr(x)O3 powders synthesized from micro powders BaCO3, ZrO2 and TiO2 at x = 0 – 0.3 have been studied. Changes in the integral absorption coefficient of the powders at different concentrations of zirconium cations were found to be within 34 %. Dielectric studies conducted over the wide ranges of temperature and frequency showed the presence of two phase transitions, one of them undergoing near the room temperatures. This fact makes it possible to consider these powders as pigments for thermal control coatings at operating temperatures of space crafts. 10.18721/JPM.14202 546.03.535.015 barium titanate-zirconate thermal control coating phase transition diffuse reflectance spectrum https://physmath.spbstu.ru/article/2021.52.2/ 02_16-27__14(2)2021.pdf

RAR RUS 28-37 Peter the Great St. Petersburg Polytechnic University Dolzhenko Dmitry ddi.dev.94@gmail.com Peter the Great St. Petersburg Polytechnic University Zakharova Irina zakharova@rhpf.spbstu.ru Peter the Great St. Petersburg Polytechnic University Sudar Nikolai sudar53@mail.ru The anomalous rise of capacitance of C60 fullerite films at low frequencies: a cause analysis A known physical fact of the anomalous rise of dielectric permittivity ε of C60 fullerite films at ac low frequencies (below 1 kHz) has not had a convincing explanation up to now. Our study was aimed at elucidating the causes of that anomaly. The p-Si/C60/InGa-eutectic structure was made and a frequency dependence of its capacitance was measured. Relying on the experimental result, a versatile analysis of the phenomenon was carried out. It was shown that the anomalous rise of ε value in the low-frequency region resulted from oxygen intercalation of fullerite with formation of C60/O2 molecular groups exhibited significant dipole momenta. The presence of such groups produced a dramatic difference between dielectric permittivity of the crystallites’ surface areas and that of their volumes. As a result, the difference led to an apparent increase in the dielectric permittivity ε of the structure under study. 10.18721/JPM.14203 537.226.1 C60 fullerite polycrystalline film permittivity Frohlich’s equation oxygen intercalation https://physmath.spbstu.ru/article/2021.52.3/ 03_28-37_14(2)2021.pdf

RAR RUS 38-52 Admiral Makarov State University of Maritime and Inland Shipping Sukhoterin Mikhail mvs1948@list.ru Admiral Makarov State University of Maritime and Inland Shipping Knysh Tatiana knyshtp@gumrf.ru Admiral Makarov State University of Maritime and Inland Shipping Pastushok Elena pastushokem@gumrf.ru Tashkent Financial Institute Abdikarimov Rustamkhan rabdikarimov@mail.ru Stability of an elastic orthotropic cantilever plate The paper studies the stability of an elastic orthotropic rectangular cantilever plate under compressive forces applied to the face opposite to the seal. The aim of the study was to obtain the range of critical forces and the relevant shapes of the supercritical equilibrium. The deflection function was chosen as a sum of two hyperbolic-trigonometric series with the addition of special compensating terms for the free terms of the Fourier cosine series to the symmetric solution. For the square ribbed plate, the first three critical loads of the symmetric solution and the first critical load of the antisymmetric solution were obtained. The authors present 3D images of the respective equilibrium forms. The results of the study can be used to study the stability of cantilever elements of various structures. 10.18721/JPM.14204 531.2: 519.63 orthotropic cantilever plate stability Fourier series critical load equilibrium form https://physmath.spbstu.ru/article/2021.52.4/ 04_38-52_14(2)2021.pdf

RAR RUS 53-64 Military Space Academy named after A.F. Mozhaysky Sadin Dmitriy sadin@yandex.ru Numerical dynamics scenarios of a variable in width gas suspension layer accelerated by a passing shock wave The behavior of the interaction between a shock wave and a gas suspension layer with curved boundaries has been studied using the hybrid large-particle method, the wave running over the layer. The conducted research made it possible to reveal two-dimensional effects of double refraction (von Neumann effects), focusing or divergence of the refracted shock wave, and baroclinic instability at the gas-suspension interface with the formation of mushroom-shaped or ring-shaped vortex structures. The features of the flow nonequilibrium were brought out. These features were associated with a decrease in the intensity of the passing shock wave and the splitting of the initial separation of the media into two contact discontinuities: a jump in porosity and a contact discontinuity in the gas phase. 10.18721/JPM.14205 532.529 hybrid large-particle method gas suspension layer shock wave baroclinic instability https://physmath.spbstu.ru/article/2021.52.5/ 05_53-64_14(2)2021.pdf

RAR RUS 65-80 Peter the Great St. Petersburg Polytechnic University Shevchenko Sergei shevchenko.sergei.a@yandex.ru JSC “Command devices research institute” Konotopov Oleg konotopov96@gmail.com The dynamic characteristics of a resonator of the gyroscope based on elastic waves in solids: finite-element modeling In the paper, the eigenfrequencies of a hemispherical resonator of the Coriolis vibratory gyroscope have been studied by the finite element method (FEM) using ANSYS Mechanical. Consideration was given to the feasibility of various FE used in the ANSYS to solve the problem of determining the eigenfrequencies. The specifics of working with shell and solid-state elements were established. The results of analytical and numerical solutions of the mentioned problem were compared. The presence of «mathematical» frequency split caused by the used FEM and the unsymmetrical mesh of the FEM was noted, and the need to take this split into account when introducing the defect distribution function into the model was pointed out. The technique for finding the frequency split value resulted by added defect in the presence of «mathematical» frequency split component was demonstrated. 10.18721/JPM.14206 531.383 Coriolis vibratory gyroscopes hemispherical resonator eigenfrequency split finite element method https://physmath.spbstu.ru/article/2021.52.6/ 06_65-80_14(2)2021.pdf

RAR RUS 81-89 Peter the Great St. Petersburg Polytechnic University Tiba Ali alitiba1991@gmail.com 0000-0003-0309-5917 Peter the Great St. Petersburg Polytechnic University Berdnikov Yaroslav berdnikov@spbstu.ru Optimization of the copper-64 production from natural nickel target at a cyclotron The paper is devoted to the problem of the copper-64 isotope production engineering that is important for application in the nuclear medicine. The production is carried out by proton irradiation of a nickel target (a natural mixture of isotopes). For this purpose, the energy dependence of the protons-nickel target interaction cross-sections, protons with initial kinetic energies of 10–15 MeV in this case, has been analyzed. Besides, the half-lives of the resulting isotopes were considered. Based on the analysis, the optimal conditions (the proton beam energy and the waiting time after irradiation) for obtaining the 64Cu isotope from natural nickel were found. It was established that under conditions close to ideal, it could be expected that 64Cu radionuclide purity would be very high and reach at least 99 %. Ideal conditions mean complete separation of nickel and cobalt isotopes from the required copper one. 10.18721/JPM.14207 539.1.03 copper-64 isotope cyclotron irradiation nickel target radionuclide purity yield calculation https://physmath.spbstu.ru/article/2021.52.7/ 07_81-89_14(2)2021.pdf

RAR RUS 90-103 Peter the Great St. Petersburg Polytechnic University Rodriguez-Aguilar Benjamin rodrigesagilar.l@edu.spbstu.ru 0000-0003-0309-5917 Peter the Great St. Petersburg Polytechnic University Berdnikov Yaroslav berdnikov@spbstu.ru Diquark parton distribution functions based on the light-front AdS/QCD quark-diquark nucleon model In the paper, we present a phenomenological unpolarized parton distribution functions (PDFs) for diquarks based on the light front soft-wall AdS/QCD quark-diquark nucleon model. From a probed model consistent with the Drewll–Yan–West relation and quark counting rule, we have performed a fit of some free parameters using known phenomenological data of quark PDFs. The model considers the entire set of possible valence diquarks within the nucleon. In our investigation, we focused on the spin-0 (ud)0, spin-1 (ud)1 and spin-1 (uu)1 valence diquarks in the proton. The diquark PDFs obtained can be used in proton-proton collision simulations. 10.18721/JPM.14208 539.125.4 diquark parton distribution function AdS/QCD holography https://physmath.spbstu.ru/article/2021.52.8/ 08_90-103_14(2)2021.pdf

RAR RUS 104-117 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 An analysis of corrections to the propagation constants of a multimode parabolic optical fiber under bending The goal of our work was to study a circularly bent, weakly guiding, multimode optical fiber with a parabolic refractive index profile. With this in mind, the second-order corrections to propagation constants of longitudinally perturbed arbitrary dielectric waveguide’s modes were found using the perturbation theory. Based on that general result, a simple analytic equation describing the corrections to the propagation constants of the modes in the bent parabolic optical fiber was derived. It was shown that the increments of squares of mode propagation constants were the same for all modes. Moreover, the increments of mode propagation constants’ differences in the bent fiber were proportional to those in the straight fiber. The proportionality coefficient was independent of the mode number. The obtained results are of high importance for development of optical fiber sensors, in which fiber bending is possible. 10.18721/JPM.14209 535.3, 535-15, 535.417 fiber curvature graded index bent waveguide perturbation analysis propagation constant https://physmath.spbstu.ru/article/2021.52.9/ 09_104-117_14(2)2021.pdf

RAR RUS 118-129 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 The Ioffe Institute of the Russian Academy of Sciences Goltsev Alexander goltsev@ua.pt About the proper time and the mass of the universe For a closed universe, a modification of the quantum gravity where the dynamics is reduced to the motion in the orbit of a general covariance groups has been proposed. To connect these motion parameters, namely, proper time and spatial shifts, to observations, classical equations of motion were introduced into the quantum theory as additional conditions. The equations account for differential conservation laws for additional dynamical variables, which form the spatial density of distribution and motion of the universe's proper mass in the representation of Arnovitt, Deser and Misner (ADM). This made it possible to determine the average values of the parameters of proper time and spatial shifts in the evolutionary history of the universe. In order to preserve the homogeneity and isotropy of space, the proper mass of the universe should next be set equal to zero. Nonzero values of its proper mass (mass spectrum) were allowed in the operator canonical representation of the quantum gravity, which was also introduced instead of the ADM representation. 10.18721/JPM.14210 530.12:517.988.38(075.8) universe proper time proper mass quantization Hermitian operator Dirac spinor https://physmath.spbstu.ru/article/2021.52.10/ 10_118-129_14(2)2021.pdf

RAR RUS 130-140 Peter the Great St. Petersburg Polytechnic University Tikhomirov Victor victikh@mail.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Deflection of an interface crack from the straight-line growth due to the unstraightness of the material interface An antiplane semi-infinite interface crack propagation problem has been considered, the crack tip coinciding with the angular point of the materials interface. The exact solution of the problem was obtained using the Mellin integral transformation. Asymptotic formulas for stresses near the crack tip were constructed, and they could contain one or two singular terms. To analyze the crack growth, the Novozhilov force criterion of fracture was used. Based on the obtained exact solution, the calculation accuracy of the crack angle and the destructive load, determined using asymptotics, was estimated. The dependences of these fracture characteristics on the composition parameters were investigated. 10.18721/JPM.14211 539.3 antiplane interface crack corner point crack deflection angle breaking load https://physmath.spbstu.ru/article/2021.52.11/ 11_130-140_14(2)2021.pdf

CHR RUS 141-142 Without author Vadim Konstantinovich Ivanov (on the occasion of his 75th birthday) Vadim Konstantinovich Ivanov (on the occasion of his 75th birthday) Polytech https://physmath.spbstu.ru/article/2021.52.12/ 12_141-142_14(2)2021.pdf

CHR RUS 143-145 Peter the Great St. Petersburg Polytechnic University Klavdiev Vladimir Peter the Great St. Petersburg Polytechnic University Lupulyak Sergey Peter the Great St. Petersburg Polytechnic University Shinder Julia Fifty years of success (to the anniversary of Yuriy Yakovlevich Boldyrev) Fifty years of success (to the anniversary of Yuriy Yakovlevich Boldyrev). Polytech https://physmath.spbstu.ru/article/2021.52.13/ 13_143-145_14(2)2021.pdf