Electronic structure of a wide quantum wire in a magnetic field at ν=1\nu = 1

The density functional theory is used to study the electronic structure of a quantum wire in a magnetic field. In a GaAs quantum wire, a critical density has been found, below which the electron density has a strong spatial inhomogeneity. The effect of the disorder potential on the electron density profile in a two-dimensional electron gas is estimated

The Stability of the Quantum Hall State at ν=1\nu = 1 in Bilayer Electron Systems

The ground states of electrons in two vertically coupled quantum dots in the presence of an external magnetic field have been studied within the density functional theory. A phase diagram of the transition to the quantum Hall state in double quantum dots has been plotted for the Landau level filling factor $\nu = 1$. It has been shown that the quantum Hall state can be stable for a zero tunnel splitting. The influence of the impurity potential on the stability condition for the quantum Hall state has been analyzed

High-temperature electron hole liquid in diamond wires

The density functional theory is used to study the properties of the electron hole liquid (EHL) in diamond quantum wires. Take a quantum wire with a circular cross section with radius R. Electrons and holes move freely along the z-axis. To calculate the energy and equilibrium density of the EHL, the Schrödinger equations for electrons and holes are solved numerically. Calculations have shown that the EHL is stable in diamond wires with a radius of several exciton radii. As the radius of the quantum wire decreases, the equilibrium density increases and the EHL energy decreases. So, with the radius of the quantum wire equal to the exciton radius (1.38 nm), the equilibrium linear density and energy of the EHL can reach values of 2.2 ∙ 107 cm–1 and – 317 meV, respectively. Estimates show that for these values of density and energy, the critical temperature of the EHL is Tc ≈ 370 K

Decision Support System for Urbanization of the Northern Part of the Volga-Akhtuba Floodplain (Russia) on the Basis of Interdisciplinary Computer Modeling

There is a computer decision support system (CDSS) for urbanization of the northern part of the Volga-Akhtuba floodplain. This system includes subsystems of cognitive and game-theoretic analysis, geoinformation and hydrodynamic simulations. The paper presents the cognitive graph, two-level and three-level models of hierarchical games for the cases of uncontrolled and controlled development of the problem situation. We described the quantitative analysis of the effects of different strategies for the spatial distribution of the urbanized territories. For this reason we conducted the territory zoning according to the level of negative consequences of urbanization for various agents. In addition, we found an analytical solution for games with the linear dependence of the average flooded area on the urbanized area. We numerically computed a game equilibrium for dependences derived from the imitational geoinformation and hydrodynamic modeling of flooding. As the result, we showed that the transition to the three-level management system and the implementation of an optimal urbanization strategy minimize its negative consequences.Comment: 14 pages, 5 figures; Conference: Creativity in Intelligent Technologies and Data Science. CIT&DS 201

Approximate calculation of the basic parameters of energodinamic processes starting and stopping planetary drive

The paper presents a simplified engineering method, which at the stage of conceptual design allows you to define the parameters of the preliminary processes starting and stopping of the planetary drive. Introduction of the proposed simplifications, gives an opportunity to solve a differential equation of motion of the inertial elements of the dynamic model of the drive.В статье представлена упрощенная инженерная методика, которая на стадии эскизного проектирования позволяет определять предварительные параметры процессов включения и остановки планетарного привода. Введение предложенных упрощений дает возможность решить дифференциальное уравнение движения инерционных элементов динамической модели привода

Tumor bed brachytherapy for locally advanced laryngeal cancer: a feasibility assessment of combination with ferromagnetic hyperthermia

Purpose. To assess the feasibility of adding hyperthermia to an original method of organ-preserving brachytherapy treatment for locally advanced head and neck tumors. Methods and materials. The method involves organ-preserving tumor resection and adjunctive high-dose-rate (HDR) brachytherapy delivered via afterloading catheters. These catheters are embedded in a polymeric implant prepared intraoperatively to fill the resection cavity, allowing precise computer planning of dose distribution in the surrounding at-risk tumor bed tissue. Theoretical and experimental analyzes address the feasibility of heating the tumor bed implant by coupling energy from a 100 kHz magnetic field applied externally into ferromagnetic particles, which are uniformly distributed within the implant. The goal is to combine adjuvant hyperthermia (40 °C–45 °C) to at-risk tissue within 5 mm of the resection cavity for thermal enhancement of radiation and chemotherapy response. Results. A five-year relapse free survival rate of 95.8% was obtained for a select group of 48 male patients with T3N0M0 larynx tumors, when combining organ-preserving surgery with HDR brachytherapy from a tumor bed implant. Anticipating the need for additional treatment in patients with more advanced disease, a theoretical analysis demonstrates the ability to heat at-risk tissue up to 10 mm from the surface of an implant filled with magnetically coupled ferromagnetic balls. Using a laboratory induction heating system, it takes just over 2 min to increase the target tissue temperature by 10 °C using a 19% volume fraction of ferromagnetic spheres in a 2 cm diameter silicone implant. Conclusion. The promising clinical results of a 48 patient pilot study demonstrate the feasibility of a new organ sparing treatment for laryngeal cancer. Anticipating the need for additional therapy, theoretical estimations of potential implant heating are confirmed with laboratory experiments, preparing the way for future implementation of a thermobrachytherapy implant approach for organ-sparing treatment of locally advanced laryngeal cancer

Bohdan Pavlu and His Activities in Russia (1915—1919)

The article is devoted to the study of the political activity of one of the prominent figures of the Czech and Slovak national movement Bohdan Pavlu, who played a significant role in the Civil War in Russia. The material was documents of personal origin and official documents containing information on the activities of sCzech-Slovak organizations in Russia. The author pays attention to the evolution of political views of B. Pavlu, his attitude to the tsarist government. It is shown how external circumstances influenced the support of the course of T. G. Masaryk. Particular attention is paid to the activities of B. Pavlu during the Civil War in Russia. The novelty of the research is due to the fact that for the first time the socio-political views of one of the leaders of the Czech national movement in Russia are comprehensively studied. The relevance of the study is due to the lack of consensus in Russian society on the role of foreign intervention in the events of 1917—1922. It is proved that B. Pavlu’s activities contributed to the consolidation of the Czech and Slovak national movement in Russia. It is emphasized that it was he who formulated the concept of “Czechoslovakia”, which formed the basis for the idea of creating a single state for the two peoples

Structural defect creation by swift heavy ions in CaF2 single crystals

Calcium fluoride single crystals belong to the most popular optical materials due to their transparency in a wide spectral region..

АНАЛИЗ ОПАСНОСТИ ПРИ ВЗРЫВЕ МЕТАНОВОГО БАЛЛОНА

Consideration is given to specifics of the explosion of 50 and 80-liter methane cylinders at various operating temperatures. The authors calculated the following parameters of methane-air mixture: radius of the fireball, speed of its spread and amount of the released heat energy. The paper analyzes the fire hazard in the event of damage to methane cylinders of vehicles.Розглянуто особливості вибуху 50-ти і 80-літрових метанових балонів при різних експлуатаційних температурах. Розраховано параметри вибухів метаноповітряної суміші: радіус вогненої кулі, швидкість її поширення, кількість теплової енергії, що виділилася. Проаналізовано пожежну небезпеку при пошкодженні метанових балонів автотранспортних засобів