2304-9782, 2618-8686, 2405-7223 19 2 2026 1-191

RAR RUS 9-15 0000-0003-1120-2102 Peter the Great St. Petersburg Polytechnic University Kniazeva Maria Peter the Great St. Petersburg Polytechnic University Zhukova Natalia zhukovaaa3781@gmail.com Peter the Great St. Petersburg Polytechnic University Vakulenko Aleksandr sasha705@mail.ru The effect of electric field switching modes on polarization properties of the lead zirconate titanate-based epitaxial heterostructures In order to extend the serviceability of ferroelectric devices, this paper proposes an experimental approach (for the first time) to clearing up the mechanism of polarization fatigue development in a lead zirconate titanate-based ferroelectric thin film. For this purpose, the influence of the recording pulse sequence configuration on the polarization of a selected object has been analyzed. The coercive field (CF) and remanent polarization of ferroelectric hysteresis loops were compared under two electric field application modes (they differed in the order of positive and negative pulses). The change in CF components was found to be insignificant during cyclic switching, whereas the difference between CF values reached 10% or more after pauses between the measurements. Experiments showed that the polarity of the final pulse of the switching signal set favorable conditions for stabilizing domains in the film whose dipole moment was aligned with the pulse polarity, and after resuming the measurements, a field of higher intensity was required to reverse the polarization. 10.18721/JPM.19201 538.956 ferroelectric epitaxial thin film polarization fatigue remanent polarization https://physmath.spbstu.ru/article/2026.88.1/ 01_9-15_19(2)2026.pdf

RAR RUS 16-26 Peter the Great St. Petersburg Polytechnic University Ermakova Karina karinak77777@mail.ru Peter the Great St. Petersburg Polytechnic University Zasimova Marina zasimova_ma@spbstu.ru Peter the Great St. Petersburg Polytechnic University Ivanov Nikolay ivanov_ng@spbstu.ru Study of vortex flows generated by a pulsed turbulent buoyant jet In the paper, the results of numerical modeling of the formation and propagation of vortex structures generated by a pulsed turbulent buoyant jet have been presented for the Reynolds number Re = 1.5×104, the parameter P = 3.65, and the Grashof number Gr = 3.9×105. A three-dimensional turbulent flow model based on the unsteady Reynolds equations was adopted. The angle between the jet and gravity directions was varied from 0° to 180°. The vortex cloud movement was tracked up to the moment when the maximum velocity value in the cloud became equal to 3.5% of the inlet velocity. For various α values, the power-law relationships describing the propagation of the vortex cloud and a decrease in the maximum velocity value and temperature within the cloud were obtained. 10.18721/JPM.19202 532.517 mixed convection turbulent puff pulsed jet numerical simulation https://physmath.spbstu.ru/article/2026.88.2/ 02_16-26_19(2)2026.pdf

RAR RUS 27-38 Peter the Great St. Petersburg Polytechnic University Adiatullin Vladislav vlad-adia@mail.ru Peter the Great St. Petersburg Polytechnic University Galaev Sergey galaev@spbstu.ru Peter the Great St. Petersburg Polytechnic University Ris Vladimir vvris@spbstu.ru Peter the Great St. Petersburg Polytechnic University Zasimova Marina zasimova_ma@spbstu.ru Peter the Great St. Petersburg Polytechnic University Ivanov Nikolay ivanov_ng@spbstu.ru On the instability of counterflowing wall jets in a ventilated cavity The paper presents the results of numerical simulation of fluid flow in a rectangular room when fluid is supplied from two opposing slotted holes. The Reynolds number (Re) based on the height of the supply opening was varied from 20 to 140. For the given ratio of the lengths of the sides of the room, intensive self-oscillations developed due to instability arising when the supply jets interacted at Re ≥ 50. Already at a value of Re = 100 the flow became chaotic with a continuous frequency spectrum. The Strouhal number values corresponding to the main frequency of the oscillations depended weakly on Re and were approximately 3·10−3. 10.18721/JPM.19203 532.517 numerical simulation plain jet ventilated cavity self-oscillations https://physmath.spbstu.ru/article/2026.88.3/ 03_27-38_19(2)2026.pdf

RAR RUS 39-56 0000-0003-4555-0009 Peter the Great St. Petersburg Polytechnic University Baranov Maksim baranovma1993@gmail.com 0000-0002-8308-059X Peter the Great St. Petersburg Polytechnic University Tsybin Oleg otsybin@rphf.spbstu.ru Supercomputer simulation of the dynamics of oligomers of a number of amino acids (Gly, Ala, Trp, Val) in the infrared electromagnetic field Supercomputer simulation of several amino acid oligomers using the molecular dynamics method has made it possible for the first time to identify a complex of characteristics of both intrinsic intramolecular local vibrations, or normal modes, and forced vibrations when specifying an alternating electric field in the IR frequency range. Amplitude-time dependences of energy and electric dipole moment were obtained for oligomers of Gly, Ala, Trp, Val amino acids, the Fourier transform of which revealed their frequency spectra. The type of solvent model was shown to significantly affect the position of spectral peaks because of variations in local interactions and system dynamics. The interpretation of the obtained patterns made it possible to propose a non-contradictory model that satisfied the fundamental physical concepts of the intramolecular and intermolecular dynamics of groups of biomolecules. The model allows for intramolecular interactions of normal local vibrations, including those of the Fermi resonance type. 10.18721/JPM.19204 53.093, 53.096, 57.031, 57.033, 57.038 molecular dynamics simulation amino acid biomolecular electronics https://physmath.spbstu.ru/article/2026.88.4/ 04_39-56_19(2)2026.pdf

RAR RUS 57-67 Peter the Great St. Petersburg Polytechnic University Dolzhenko Dmitry ddi.dev.94@gmail.com Peter the Great St. Petersburg Polytechnic University Letkiman Egor letkiman.egor@gmail.com The influence of a silica trench profile on the photosensitivity of a CMOS-compatible APD in the visible range This work has involved the simulation of technological operations of manufacturing a silicon (Si) avalanche photodiode and calculating its output characteristics. As a result, the values of its multiplication factor (from 49.5 to 63.3) and spectral sensitivity (from 15.8 to 19.6 A/W) depending on the shallow trench insulation defect type are presented for a Si avalanche photodiode. It has been shown that the technological defects causing narrowing of the width of the trench towards its bottom have the greatest impact on these parameters. As a result, the multiplication factor decreases to 18%. The dependence of the photodiode gain on the trench’s wall inclination angle was established to be described well by a linear function. It was also demonstrated that the trench narrowing led to an increase in the lateral component of the electric field strength near the groove, which reduced the breakdown voltage, but did not lead to an increase in multiplication. 10.18721/JPM.19205 621.383.523 avalanche photodiode multiplication factor spectral sensitivity technological defects STI TCAD https://physmath.spbstu.ru/article/2026.88.5/ 05_57-67_19(2)2026.pdf

RAR RUS 68-75 0000-0003-2327-068X Mechanical Engineering Research Institute of the RAS Alifov Alishir a.alifov@yandex.ru The mixed parametric and self-oscillations: The effect of nonlinear parametric excitation and delays on them causing self-oscillations In the paper, the mixed parametric and self-oscillations in the presence of a nonlinear parametric action and a delay in friction causing self-oscillations have been studied. For this purpose, a model of a frictional self-oscillating system interacting with an energy source of limited power was used. The solution of nonlinear differential equations of motion was constructed using the direct linearization method. The relations of nonstationary and stationary oscillation modes were obtained. By application of the Routh – Hurwitz criteria, the conditions for the stability of stationary oscillations were derived. The calculations were carried out in order to gain information about the dynamics of fluctuations. An analysis of the data showed that the amplitude-frequency dependence changed its behavior under the influence of the delay. The latter also led to the appearance of stability regions on the lower branches of the amplitude curves, and a dependence arose on the steepness of the energy source characteristic. 10.18721/JPM.19206 534.16 nonlinearity parametric excitation delay mixed oscillations parametric oscillations self-oscillations method linearization energy source https://physmath.spbstu.ru/article/2026.88.6/ 06_68-75_19(2)2026.pdf

RAR RUS 76-83 0009-0006-9088-3581 Peter the Great St. Petersburg Polytechnic University Kozlovsky Stanislav skozlovski@phmf.spbstu.ru 0000-0003-0309-5917 Peter the Great St. Petersburg Polytechnic University Gunkov Pavel gunkov-pavel@yandex.ru 0000-0003-0309-5917 Peter the Great St. Petersburg Polytechnic University Berdnikov Yaroslav berdnikov@spbstu.ru The Federal Budgetary Institution “State Regional Center for Standardization, Metrology and Testing in St. Petersburg and Leningrad Region” (“Test-St. Petersburg”) Donskikh-Tyrsa Victor vdt.test.spb@gmail.com The thickness determination of coatings by X-ray fluorescent analysis using a calibration curve obtained by calculations When measuring a coating thickness by X-ray fluorescent analysis, the preliminary calibration of the detection system is required using reference samples with a known coating thickness. This operation is quite time-consuming and gives results only for a certain detection system and a pair of elements (the base material and coating). In our study, the calibration curve has been obtained by the Monte Carlo calculation method using the MCC 3D software. In so doing, we calculated the dependences of the ratios of peak intensities of fluorescence lines from Fe Kα (substrate) and Zn Kα (coating), as well as Cu Kα (substrate) and Au Lα (coating) on the values of coating thickness. Moreover, the coating thickness determination errors were obtained. A conclusion was made about the possibility of using the Monte Carlo method to determine the coating thickness without preliminary calibration. 10.18721/JPM.19207 539.1.075 X-ray fluorescence analysis thickness substrate thin film simulation Monte Carlo method https://physmath.spbstu.ru/article/2026.88.7/ 07_76-83_19(2)2026.pdf

RAR RUS 84-97 0000-0001-6067-8196 Tashkent State Technical University Named after Islam Karimov Khujaniyozov Jumanazar KhujaniyozovJB@mail.ru 0000-0002-9815-2111 Tashkent State Technical University Named after Islam Karimov Umirzakov Baltokhodja be.umirzakov@gmail.com

2, Universitetskaya St., Tashkent,100095, Uzbekistan

0000-0001-5813-7518 Tashkent State Technical University Named after Islam Karimov Tashmukhamedova Dilnoza ftmet@mail.ru 0000-0003-3103-7060 Peter the Great St. Petersburg Polytechnic University Loboda Vera vera_loboda@mail.ru 0000-0002-5732-6103 Tashkent State Technical University Named after Islam Karimov Abduvayitov Akbarjon akbarjon.abduvayitov@gmail.com The influence of Ar+and Cd+ ion implantation on the composition and electronic structure of monocrystalline zinc telluride The effect of Ar+ and Cd+ ion implantation and subsequent thermal annealing has been studied on a single-crystal ZnTe (111) using a whole range of spectroscopy methods: ultraviolet photoelectron one (UPS), light absorption one, and Auger electron one (AES). The results showed that bombardment of the surface with Ar+ and Cd+ ions with an energy of E0 = 1 keV until a saturation dose of of Dsat = (6–8)·1016cm−2 was reached resulted in the destruction of the crystal structure of the ion-implanted layers and, as a consequence, in surface metallization. In particular, after implantation with Cd+ ions and subsequent annealing at T = 850 K, the formation of a homogeneous continuous Zn0.5Cd0.5Te film 30–35 Å thick was observed, which indicated the redistribution of components and the formation of a new phase state on the ZnTe surface. The results of the study of Zn0.5Cd0.5Te thin films demonstrate the presence of two clearly defined maxima in the valence electron spectra corresponding to binding energies of −1.4 eV and −5.2 eV. 10.18721/JPM.19208 538.971 : 621.315.592 heterostructure photoelectron spectroscopy implantation molecular beam epitaxy saturation dose thin film zinc telluride https://physmath.spbstu.ru/article/2026.88.8/ 08_84-97_19(2)2026.pdf

RAR RUS 98-106 0009-0004-6988-9685 Peter the Great St. Petersburg Polytechnic University, Klevtsov Anton klevtsov_ai@spbstu.ru P-6861-2015 10041592700 https://orcid.org/0000-0003-2511-0188 Karaseov Platon platon.karaseov@spbstu.ru 0000-0003-4933-9534 Peter the Great St. Petersburg Polytechnic University Titov Andrey ATitov@spbstu.ru Radiation defect formation during sequential ion bombardment of alpha-gallium oxide This paper presents the results of a study of radiation damage accumulation in α-Ga2O3 under sequential bombardment with fluorine and phosphorus ions with varying energies of the keV range. A significant effect of the ion irradiation sequence on both the number and depth distribution profile of stable defects was established. The physical nature of this noncommutativity is discussed. 10.18721/JPM.19209 539.1.043 gallium oxide ion implantation sequential irradiation radiation defects Rutherford backscattering https://physmath.spbstu.ru/article/2026.88.9/ 09_98-106_19(2)2026.pdf

REV RUS 107-135 Peter the Great St. Petersburg Polytechnic University Zhurikhina Valentina zhurikhina@mail.edu.ioffe.ru Peter the Great St. Petersburg Polytechnic University Babich Ekaterina babich.katherina@gmail.com 0000-0002-1744-5976 Alferov University, RAS Terpitskiy Aleksey terpiczkij@mail.ru 0000-0002-9749-8751 Institute of Nuclear Physics, Academy of Sciences of the Republic of Uzbekistan Nuritdinov Izzatillo izzatilloh@yahoo.com Sharof Rashidov Samarkand State University Rakhmatov Mashrab mashrab-r@gmail.com 0000-0001-8283-791X Sharof Rashidov Samarkand State University Eshbekov A'zamkul eshbekov-a@mail.ru Plasmonic nanomaterials formed by ion exchange in glass: properties and applications Plasmonic materials based on noble metal nanostructures exhibit unique optical properties in the visible range. Currently, plasmons supported by metal nanoparticles or propagating along metal interfaces are attracting increasing attention in sensorics, medicine, imaging, nanophotonics, and optoelectronic technologies. This article has provided a brief overview of two main plasmonic modes: surface plasmon polaritons at metal interfaces and localized plasmons in nanostructures. It also discussed the physical principles of plasmon-enhanced sensors, such as colorimetric, plasmon-enhanced fluorescence, and surface enhanced Raman scattering ones. These sensors are widely used in healthcare, security, food processing, and environmental monitoring. The fabrication of plasmonic nanostructures in glasses using ion exchange and their application for detecting chemical compounds and biological objects was discussed. 10.18721/JPM.19210 538.9 + 538.975 localization of light nanostructure ion exchange plasmon electromagnetic field amplification sensor https://physmath.spbstu.ru/article/2026.88.10/ 10_107-135_19(2)2026.pdf

RAR RUS 136-146 Homs University Yousef Rasha ryousef@homs-univ.edu.sy Al-Hawash Private University Yousef Areej areejyousef@hpu.edu.sy Al-Wataniya Private University Nassif Alaa alaa.nassif@wpu.edu.sy

Al-Wataniya Private University, International Hama‒Homs‎ Highway, Hama, XQ92+PMC, Syria

0000-0002-3991-5318 University of Kufa Kadhim Shaymaa shaymaa.alshebly@uokufa.edu.iq Structural properties of some nanocrystalline spinel chromites prepared by solid-state reaction method Chromium nanocomposites MCr2O4 have been synthesized by a solid-state reaction. The synthesized samples were characterized using X-ray powder diffraction technology (XRD). The temperature of synthesis was 1000°C for NiCr2O4 and 900°C for Zn Cr2O4. Miller indices (hkl) were calculated for the production, and the compounds were shown to have cubic structure FCC. The lattice parameters were as follows: a = 8.26 Å, Z = 8, V = 564.26Å3 and a = 8.2650 Å, Z = 8, V = 564.58 Å3 for NiCr2O4 and ZnCr2O4 respectively. The space group of symmetry is Fd3m for the both. The grain sizes were calculated by the Debye – Scherrer formula for the two compounds and were 31.92 nm and 32.78 nm, respectively. The ZnCr2O4 and NiCr2O4 nanoparticles' morphology was examined using scanning electron microscopy (SEM). The SEM images showed the agglomeration of the nanoparticles, which were formed of square-shaped nanocrystallites. 10.18721/JPM.19211 54.057 MCr2O4 spinel solid-state reaction method grain size https://physmath.spbstu.ru/article/2026.88.11/ 11_136-146_19(2)2026.pdf

RAR RUS 147-159 Peter the Great St. Petersburg Polytechnic University Goncharov Ivan bing_fox.2001@inbox.ru Peter the Great St. Petersburg Polytechnic University Sadova Aleksandra aleksa.sadova@yandex.ru Peter the Great St. Petersburg Polytechnic University Nuzhin Ilia ilia.nuzhin@yandex.ru Peter the Great St. Petersburg Polytechnic University Tenitskaya Polina 89818372011@mail.ru Peter the Great St. Petersburg Polytechnic University Kurdyumova Inna Peter the Great St. Petersburg Polytechnic University Gorkovskaia Aleksandra alexgorkovskaya@gmail.com 0000-0003-0562-0156 Peter the Great St. Petersburg Polytechnic University Khodorkovskii Mikhail khodorkovskii@gmail.com 0000-0003-4371-265X Peter the Great St. Petersburg Polytechnic University Alekseev Aleksandr alex35093@gmail.com Differences in the interaction of RAD51 and UvsX recombinases with DNA revealed by single-molecule experiments Nucleoprotein filaments formed by recombinase proteins on DNA are key structures of the homologous recombination process, which ensures the maintenance of the genome stability. Filament formation on DNA leads to a significant change in the mechanical properties of the complex, in particular to DNA lengthening, while the kinetics of filament assembly depends on mechanical tension. Using optical tweezers, this study has obtained data on the assembly dynamics of human RAD51 recombinase and bacteriophage T6 UvsX recombinase filaments on double-stranded DNA under varying mechanical tension. In the range between 3 and 12 pN, RAD51 efficiently bound to DNA, forming filaments with a high coverage. In contrast to RAD51, an efficient UvsX filament formation occurred only under high tension (12 pN), whereas UvsX binding to DNA was severely restricted at 3–6 pN. The different tendency of the two recombinases to interact with DNA reflected their adaptation to cellular environments and regulatory mechanisms governing homologous recombination.  10.18721/JPM.19212 577.24 homologous recombination RAD51 UvsX RecA cancer treatment recombinase polymerase amplification optical tweezers nucleoprotein filament https://physmath.spbstu.ru/article/2026.88.12/ 12_147-159_19(2)2026.pdf

RAR RUS 160-170 Peter the Great St. Petersburg Polytechnic University Bannikov Egor bannikov.ev.21@gmail.com 0000-0003-0309-5917 Peter the Great St. Petersburg Polytechnic University Berdnikov Yaroslav berdnikov@spbstu.ru Peter the Great St. Petersburg Polytechnic University Larionova Dariya dlar@bk.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

0000-0002-3395-0454 Peter the Great St. Petersburg Polytechnic University Kotov Dmitry dmitriy.kotov@gmail.com Peter the Great St. Petersburg Polytechnic University Basirov Kirill kirill.basirov@mail.ru Peter the Great St. Petersburg Polytechnic University Borisov Ivan borisov.ii@edu.spbstu.ru Azimuthal dependences of the nuclear modification factors of π0 mesons in Cu+Au collisions at an energy of 200 GeV and U+U collisions at 193 GeV The paper presents the results of calculating the nuclear modification factors of π0 mesons as a function of their transverse momentum and azimuthal angle at different collision centralities of Cu+Au at an energy of 200 GeV and U+U at 193 GeV. As a result of the analysis of the obtained data, it was established that the azimuthal dependence of the nuclear modification factors of π0 mesons in both collision systems demonstrated universality in the considered range of transverse momentum and could be explained by the dependence of parton energy losses on the length of their path in the quark-gluon plasma (QGP). It is advisable to use these azimuthal dependences of nuclear modification factors for clarification of the parameters in theoretical models describing the energy losses of partons in the QGP formed in collisions of deformed nuclei or in asymmetric collision systems. 10.18721/JPM.19213 539.12 quark-gluon plasma azimuthal anisotropy nuclear modification factors π0 meson https://physmath.spbstu.ru/article/2026.88.13/ 13_160-170_19(2)2026.pdf

RAR RUS 171-177 Peter the Great St. Petersburg Polytechnic University Kruashvili Dmitry kruashvili.dv@edu.spbstu.ru 0000-0003-0309-5917 Peter the Great St. Petersburg Polytechnic University Berdnikov Yaroslav berdnikov@spbstu.ru Double longitudinal spin asymmetry of J/ψ mesons produced in proton-proton collisions with longitudinal polarization The paper puts forward an extension of the Pythia8 software package, which makes it possible to calculate collisions of longitudinally polarized protons with the production of J/ψ mesons. The transverse momentum spectra of J/ψ mesons and the double longitudinal spin asymmetry of them at an energy of 510 GeV have been obtained. The calculated results were compared with experimental data, and a satisfactory agreement between them was established. This success served as the basis for predicting the results of the SPD experiment at the NICA collider. The corresponding calculations of the transverse momentum spectrum and the double longitudinal spin asymmetry of the J/ψ meson at an energy of 27 GeV were presented. All conclusions were based on the collinear parton model. 10.18721/JPM.19214 532.517 Pythia8 double longitudinal spin asymmetry parton distribution function parton cross section https://physmath.spbstu.ru/article/2026.88.14/ 14_171-177_19(2)2026.pdf

RAR RUS 178-188 0000-0001-8831-743X Peter the Great St. Petersburg Polytechnic University Smirnova Nina smirnova_na@spbstu.ru The damping of pendulum oscillations using a parametric controller In the paper, the efficiency of a parametric damping system for the oscillations of a linear, initially, lightly damped pendulum has been studied. A closed-loop stabilization system included the feedback based on the deviation of the simple pendulum's position from the prearranged one. Our system was equipped with a controller whose structure followed from the Mathieu equation, and the variable coefficients were selected taking into account the proposed methodology. The parametric controller (PC) was shown to be able to shorten the settling time via increasing the damping. Because of this, it makes sense to add the PC to a system with a traditional offset-based P-controller to improve dynamic performance and to increase accuracy in the steady state. Moreover, the PC successfully suppressed harmonic external disturbances. The PC based on the offset of one link was constructed for a planar two-link pendulum. The controller damped lower frequency oscillations, but this turned out to be enough to significantly improve the stabilization response. 10.18721/JPM.19215 531.53 linear lightly damped pendulum first parametric resonance feedback system parametric controller https://physmath.spbstu.ru/article/2026.88.15/ 15_178-188_19(2)2026.pdf