Faculty of Physics
M.V.Lomonosov Moscow State University

# Выпуски журнала

## Equations of state of a system of hard spheres in a reduced form

### P. N. Nikolaev

Memoirs of the Faculty of Physics 2021. N 4.

The equations of state are investigated for a system of hard spheres in the general quantum-mechanical case. The equations are presented in the reduced form. A comparison is made between the classical approximation, the semiclassical approximation with allowance for the first correction, and the cell-cluster expansion with allowance for three-particle clusters, inclusive. The cell-cluster expansion, as calculations show, is more efficient than the semiclassical approximation at high densities. It is shown that the density dependence in the caloric equation of state is significant, which is also preserved at high temperatures. In the general case, Joule's law does not hold for a system of hard spheres.

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## Study of atmospheric optical phenomena with Physics faculty students

### S. B. Ryzhikov$^1$, Yu. V. Ryzhikova$^2$

Memoirs of the Faculty of Physics 2021. N 4.

The authors draw attention to the fact that the description of the mechanism of the rainbow and halo formation is absent in both school and university textbooks and teaching aids. An explanation of these phenomena is given in the popular science literature, but there is no indication of the fact of the polarization of the rainbow and the reasons for this polarization. At the same time, these phenomena can be studied within the framework of a general course in physics, spending about half an hour in seminars. The article provides a methodology for studying rainbows and halos with students. In addition, the authors draw attention to a common mistake associated with the history of Descartes' study of the rainbow.

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## Problems of dynamical theory in statistical physics of liquid

### P. N. Nikolaev

Memoirs of the Faculty of Physics 2021. N 4.

In the paper it is investigated the process of formation of the modern dynamic theory liquid. The activity of N.N.Bogoliubov on the creation of a dynamic theory in statistical physics and the influence of his work on the formation of a dynamic theory of liquid are presented.

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## Experience in teaching courses «General issues of methods of teaching physical and mathematical disciplines» and «Fundamentals of teaching physics at a university» in a remote format

### T. A. Bushina, A. I. Slepkov

Memoirs of the Faculty of Physics 2021. N 4.

The experience of teaching the courses "General issues of methods of teaching physics and mathematics in higher education" for master's students and "Fundamentals of teaching physics in higher education" for postgraduate students in a distance format at the Faculty of Physics of Moscow State University in the autumn semester of the academic year 2020-2021 is discussed. In the context of the coronavirus pandemic, these courses, like other lecture courses taught at the Faculty of Physics, had to be transferred to a remote format. As a result, in order to maintain interest in the courses and not lose feedback from the listeners, the principles of working with students and postgraduates were reworked. This paper discusses new approaches to working with students and postgraduates, provides examples of tasks that were offered to be performed in a remote format.

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## Reports defending in General physics laboratory course using e-learning technologies: experience, drawbacks, perspectives

### V. E. Buravtsova, A. V. Seliverstov

Memoirs of the Faculty of Physics 2021. N 4.

The experience of e-learning methods usage for intgrated development of student competences had analyzed. As a teaching method students' specific activity within the General physics laboratory course had proposed: the laboratory activities considered as scientific research. The results of distance education methods usage had described, some significant advantages have found.

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## The framework for General physics webinars

### A. V. Seliverstov

Memoirs of the Faculty of Physics 2021. N 4.

The principles of construction of the framework for General physics webinars are described. The experience of its realization using Discord application and Google Workshop utiltites is discussed.

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## Isospin splitting of the giant dipole resonance of atomic nuclei

### I. M. Kapitonov

Memoirs of the Faculty of Physics 2021. N 3.

A simple estimate of the magnitude of the isospin splitting of the giant dipole resonance of atomic nuclei based on the concept of isospin symmetry of the nucleon-nucleon interaction is proposed. The obtained value of this splitting exceeds that traditionally used and better describes the experimental data for heavy nuclei.

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## Raman spectroscopy for monitoring the dissolution of silicon nanocrystals in model liquids and living cells

### D. E. Maksutova$^1$, U. A. Tsurikova$^1$, M. B. Gongalsky$^1$, Y. V. Evstratova$^{1,2}$, A. A. Kudryavtsev$^{1,2}$, L. A. Osminkina$^{1,3}$

Memoirs of the Faculty of Physics 2021. N 2.

Raman spectroscopy is an informative experimental technique for studying the properties of both solid-state and biological objects. In this work, the Raman scattering method was used to study the dissolution of silicon nanocrystals (nc-Si) during their incubation in phosphate buffered saline (PBS) at 37 ° C, and with BT474 human breast carcinoma cells. Aqueous suspensions of silicon nanoparticles (SiNPs) with a diameter <90 nm were obtained by grinding arrays of porous silicon nanowires. The microphotographs of scanning and transmission electron microscopy show that nanowires and SiNPs consist of small nc-Si and pores. It was shown that incubation of nanoparticles in PBS and in cells results in a low-frequency shift of the maximum and broadening of the Stokes component of the Raman spectrum of SiNPs, the appearance of a signal from the amorphous silicon phase, a decrease in the intensity, and then complete disappearance of the signal, which indicates a decrease in the size, and then a complete dissolution of nc-Si. The results presented in this work are promising for the development of biodegradable drug delivery systems based on SiNPs.

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## Characteristics of a quasi-stationary pulsating transverse-longitudinal discharge in high-speed propane-air flows

### I. K. Nesterenko, K. N. Kornev, A. A. Logunov, V. M. Shibkov

Memoirs of the Faculty of Physics 2021. N 2.

The paper considers the prospects of using a quasi-stationary pulsating discharge to control the process of supersonic combustion of hydrocarbon fuels. The discharge characteristics have been obtained experimentally under conditions of subsonic and supersonic air flow. Supersonic steady combustion of propane in expanding aerodynamic channels of various configurations has been implemented. The results obtained confirm the efficiency of using low-temperature plasma in supersonic plasma aerodynamics.

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## Filtration and rheological characteristics of low-permeability reservoir rocks when modeling directional unloading method

### V. I. Karev, Yu. F. Kovalenko, V. V. Khimulia

Memoirs of the Faculty of Physics 2021. N 2.

This work is devoted to the study of rheological, deformation and filtration properties of low-permeability rocks of Achimov deposits of the Urengoy gas condensate field using the directional unloading method. As part of the study, physical modeling of the real stresses in the vicinity of the well was carried out when implementing the directional unloading method. Experiments were conducted by using the unique facility, Triaxial Independent Load Test System of the Institute for Problems in Mechanics of the Russian Academy of Sciences. Modeling was carried out for two types of bottomhole design: an open hole and a perforation tip in a cased hole. The dependence of the filtration properties of rocks on the type of stress-strain state is shown; conclusions are drawn about the nature of creep. The values of pressure drawdown, which leads to an increase in the permeability, are determined. The results obtained indicate that the directional unloading method can be successfully applied to wells drilled in the Achimov deposits.

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