https://elib.bsu.by:443/handle/123456789/332868 NPCS Vol.27, no.2 (2024), pp. 104-207 2026-04-21T03:38:11Z https://elib.bsu.by:443/handle/123456789/332892 Заглавие документа: Adiabatic Discrete Ratchet Effect of a Rotor in the N-well Potential of Hindered Rotation Авторы: Shapochkina, I. V.; Rozenbaum, V. M. Аннотация: We consider the azimuthal hopping motion of a polar rotor with a dipole moment µ in a periodic N-well potential of hindered rotation under the influence of adiabatic symmetric dichotomous fluctuations of an external electric field ±E with a period τ. A general expression is obtained for the average angular velocity Ω of unidirectional discrete rotation as a function of the direction ϕE of the applied field and the ratio ε = µE/kBT of the energy of the rotor-electric field interaction to thermal energy. The analysis of the symmetry of the obtained expression shows that the ratchet effect is absent for odd N, as well as for field orientations ϕE = 0, π/N, which coincide with the axes of potential wells and barriers with even N’s. With quadratic accuracy in ε ˝ 1, there is also no ratchet effect for N > 2. If N is even and ϕE = π/(2N), the absolute value of the average angular velocity is proportional to εN at ε ˝ 1 and tends to 2π/τ at ε/N2 ˛ 1. Graphical dependencies (τ/2π)Ω(ε, ϕE) are represented for N = 2, 4, 6, 8. 2024-01-01T00:00:00Z https://elib.bsu.by:443/handle/123456789/332891 Заглавие документа: Calculation of DPA for the VVER-1200 Reactor Vessel Авторы: Khrushchinsky, A. A.; Kuten, S. A.; Babichev, L. F. Аннотация: Neutron irradiation damage is of the most critical damage mechanisms in reactor vessel (RV) steel. Neutrons transfer their kinetic energy to target atoms of RV steel that start to jump creating vacancies and interstitials known as Frenkel Pairs (FP). The FPs are responsible for formation of defected clusters and microstructural modifications. These effects deteriorate physical and mechanical properties of the RV steels among which results in limiting the lifetime of reactor vessel. The most sensitive location in the RV related neutron irradiation damages is the area adjacent to the middle of the reactor core. In this paper, Monte Carlo simulation of the detailed reactor core have led to identifying the areas maximum neutron flux in the RV. Then the SRIM/TRIM Monte Carlo codes are used to evaluate the neutron spectral-averaged Displacements Per Atom (DPA) values for the RV region with the most intense neutron irradiation. 2024-01-01T00:00:00Z https://elib.bsu.by:443/handle/123456789/332890 Заглавие документа: Dynamical Mode of Laser Radiation in Quantum Dots Structures with the Optical Stark Effect Авторы: Timoshchenko, E. V. Аннотация: Within the framework of the proposed balance model, the dynamics of stimulated emission in active media, which are characterized by the optical Stark effect, has been studied. It has been shown that the nonlinear shift of resonant transition levels, caused by the optical Stark effect, is an instability factor in the kinetic scheme of the laser. The ranges of values of the excitation (pumping) level and linear resonance detuning were found for which spontaneous transition of stimulated emission to the regime of self-oscillations of intensity is possible. Simulations of the relaxation dynamics of radiation have been carried out for typical parameters of lasers based on semiconductor quantum-sized structures for near-IR range. 2024-01-01T00:00:00Z https://elib.bsu.by:443/handle/123456789/332889 Заглавие документа: Isomers of Fullerenes C58 to C60 Авторы: Melker, A. I.; Matvienko, A. N.; Krupina, M. A. Аннотация: We have designed possible structures of isomers of fullerenes from C58 to C60. The fullerenes studied refer to four-, five- and six-fold symmetry, they being divided into two classes, perfect (basic) having ordinary symmetry and intermediate having topological symmetry. We have used three the most natural mechanisms of their formation, namely, fusion of carbon cupolas having the same symmetry; fusion of fullerenes having compatible symmetry and embedding carbon dimers into the hexagons with a specific surrounding of initial fullerenes. The energies of the fullerenes calculated through the use of molecular mechanics are presented together with their graphs. We have separated fragments of curvature and put into accordance with their centers the centers of principal stresses. The arrangement of both centers for the five observed experimentally isomers of fullerene C60 corresponds to five geometric figures: icosahedron, pentagonal, hexagonal, deformed hexagonal bipyramids and cube. As a result the binding energy of isomers can be considered not only as a global quantity, but as a surface distribution. 2024-01-01T00:00:00Z