The paper provides a comparative analysis of three options for constructing the Schrödinger equation in phase space: the Torres-Vega method, from the Vlasov equation and the Moel equation. Each approach gives its own version of the Schrödinger equation in phase space. Exact solutions corresponding to a quantum harmonic oscillator are considered for each equation.
Show AbstractIn the paper there are investigated the basic reference systems in the statistical thermodynamics of liquids from the point of view of the expediency of their use in thermodynamic perturbation theory. A quantum hard-sphere system widely used in this field is considered. As is known, the Wigner-Uhlenbeck-Gropper expansion is not suitable for nonanalytic potentials. Therefore, a special expansion into a series method is used in this work, the efficiency of which has been verified by the example of argon and helium 4.
Show AbstractA new method for modeling the self-organization of two-dimensional dendrites with stochastically generated growth centers is proposed. Algorithms for the formation of fractal dendritic clusters are considered. Estimates of the fractal dimension of dendritic structures are given.
Show AbstractWe present a realization of the maximum-likelihood technique, which is one of the latest modifications of the Baade--Becker--Wesselink method. It allows one to estimate the key Cepheid parameters, the distance modulus, and the interstellar reddening, combining photometric and spectroscopic data (including the effective temperature data). This method is applied to the sample of 44 Galactic Cepheids, for which multiphase temperature measurements are available. The additional data correction is performed to subtract the impact of the component in binary/multiple systems. We also study the effect of shock waves, whose presence in the stellar atmosphere distorts the observational data and leads to systematic errors in the obtained parameters. As a result, we obtain the following period-luminosity relation: $M_v = - (2.67 \pm 0.16) \cdot (log\,P - 1) - (4.14 \pm 0.05)$. Despite the fact that the final calibration is in reasonable agreement with the relations calculated using trigonometric parallaxes, a slight zero-point offset is found, indicating the brighter Cepheids and therefore the longer distance scale. Thus, the Hubble constant estimate based on our period-luminosity relation has to be lower.
Show AbstractThe results have been presented of a comprehensive study of the structural state, chemical and phase composition, micromechanical and tribological properties of the vacuum-deposited coatings obtained via reactive magnetron sputtering of silicon targets.
Show AbstractMagnetic properties in two multilayer nanostructures [(CoFeB)$_{60}$C$_{40}$/SiO$_2$]$_{200}$ and [(CoFeB)$_{34}$(SiO$_2$)$_{66}$/C]$_{46}$ with different contents of the CoFeB magnetic alloy in metal-composite layers and an inverted arrangement of nonmetallic phases C and SiO$_2$, in composite layers or in interlayers were investigated by magneto-optical methods. Using the spectral and field dependences of the transverse Kerr effect (TKE), it was found that in both MNSs the magneto-optical response and magnetic order are determined by the composition of the composite layers. In the MNS [(CoFeB)$_{60}$C$_{40}$/SiO$_2$]$_{200}$ with a post-percolation content of metal clusters, the maximum absolute values of the TKE decrease by about 2.5 times in comparison with the pure amorphous CoFeB alloy, while the form of the field dependences of the TKE in this MNS has features characteristic of soft ferromagnets. In another MNS [(CoFeB)$_{34}$(SiO$_2$)$_{66}$/C]$_{46}$ with a pre-percolation content of metal clusters in the SiO$_2$ oxide matrix, the TKE spectral dependences fundamentally differ from the TKE of the initial amorphous CoFeB alloy both in shape and sign. The field dependences of the TKE of this MNS are linear in nature, characteristic of superparamagnets.
Show AbstractThe results of the investigation of the magneto-optical properties of thin-film Co/Gd/Co systems obtained by ion-plasma magnetron sputtering are presented. The thickness of the Co layers was 5.0 nm, and the Gd one varied from 0.1 to 9.0 nm. It was found that the shape of the spectral dependences of the equatorial Kerr effect of the studied samples is almost identical and similar to the magneto-optical spectra observed for cobalt films. With that, the magnitude of the magneto-optical effect depends on the thickness of the Gd layer. In particular, it decreases with increasing thickness of the Gd layer. This fact is explained by a decrease in the contribution of the cobalt layer to the magneto-optical signal with rising thickness of the Gd layer.
Show AbstractThe results of the investigation of the dependence of the magnetic properties and magnetic- field behavior of thin-film three-layer Co/Gd/Co systems on temperature in the range from 100 to 300 K are presented. The samples were obtained by ion-plasma magnetron sputtering. The thickness of the Co layers is 5.0 nm, and Gd layers, tGd, varied from 3.0 to 9.0 nm. The volume magnetic characteristics were studied using a vibrating sample magnetometer with the field oriented parallel to the plane of the samples. It is found the temperature influence on the magnetic characteristics and magnetic field behavior of the samples. In particular, the shape of the hysteresis loops depends on the thickness of the Gd layer and the temperature. The dependences of the magnetic moment and coercive force on temperature are found. As the temperature changes from 100 to 300 K, an increase in the values of the magnetic moment of the samples is observed, as well as a decrease with an increase in tGd. It is discovered that the values of the coercive force decrease with an increase in temperature from 100 to 300 K. It is found that the magnetic compensation point for a sample with tGd = 9 nm is T = 150 K.
Show AbstractThe process of formation of modern teaching methods and scientific research in the field of theoretical physics in the thirties of the twentieth century at Moscow University is investigated. During this period, a whole galaxy of outstanding theoretical physicists was formed here. The activities in this period of I.E. Tamm, the first head of the department of theoretical physics at the Faculty of Physics, and A.A. Vlasov, his postgraduate student, who built the theory of plasma in this period based on the use of an equation called the Vlasov equation, are presented.
Show AbstractThe problem of studying science and technology history and prospect development with schoolchildren is considered. It is proposed to compare the science branch historical development and the schoolchildren research abilities development in order not only to increase the interest of students in the subject under consideration, but also to understand what personal abilities they need to develop in themselves.
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