Convergence to equilibrium for many particle systems

The goal of this paper is to give a short review of recent results of the authors concerning classical Hamiltonian many particle systems. We hope that these results support the new possible formulation of Boltzmann's ergodicity hypothesis which sounds as follows. For almost all potentials, the minimal contact with external world, through only one particle of $N$, is sufficient for ergodicity. But only if this contact has no memory. Also new results for quantum case are presented

The problem with peaking in the atmospheric magnetohydrodynamics. limiting cases

For the mathematical modelling of highly nonequilibrium and nonlinear processes in the atmosphere based on the equations of momentum and charge transfer, a thermodynamic approach is used with the model function of sources and sinks, which is characteristic for problems with peaking, where the maximum of the velocity distribution and charge distribution in space can increase without bound for a limited time. It allows to consider the general case, taking into account the interaction between the components of the velocity vector and the electromagnetic field in the presence of sources and sinks of momentum in a flat layer. As a limiting case, we consider the transfer of momentum when its source in a nonlinear medium leads to the regime with peaking, and the development of the regime generated by a nonlinear medium itself leads to self-organization. The competition between the process increment and the propagation of momentum and charge can result in appearance of new medium characteristics, such as the spatial diameter of tornado (lightning core), in which these processes balance each other. Another limiting case is the process of charge transfer in an atmosphere considered. As a result, a more general problem may be formulated, and a joint system of equations, which not only describes the behaviour of the velocity vector for an incompressible medium in the form of parabolic equation of momentum, but also takes into account the influence of electromagnetic field, may be derived

Estimations of electron-positron pair production at high-intensity laser interaction with high-Z targets

Electron-positron pairs' generation occuring in the interaction of $10^{18}$-$10^{20}$~W/cm$^2$ laser radiation with high-Z targets are examined. Computational results are presented for the pair production and the positron yield from the target with allowance for the contribution of pair production processes due to electrons and bremsstrahlung photons. Monte-Carlo simulations using the PRIZMA code confirm the estimates obtained. The possible positron yield from high-Z targets irradiated by picosecond lasers of power $10^2$-$10^3$~TW is estimated to be $10^9$-$10^{11}$

Automating of the analysis of regional sustainability to the socio-economic crises

Sustainable development of regions is a priority of the state socio-economic policy. It actualizes the need to create tools for assessing the sustainability of regional socio-economic systems. The aim of this research is to determine the degree of sustainability of a regional economic system (“slave” system) relative to the country’s economic system (“master” system). The study involves the use of different macro-economic indicators that describe the regions’ sustainability, the sustainability of businesses and sustainability of households. A methodological approach to sustainability assessment of the constituent regions of the Russian Federation was proposed using the time series analysis of macroeconomic indicators. A classification of the sustainability of region economic system according to changes, which take place in the economy of the country was the result of the study. Based on this method, a software product was developed in order to automate the process of evaluation and classification of the sustainability of the Russian Federation. The article describes the functionality and possibility of practical use of the software product. The program has flexible settings and allows the user to quickly identify the main trends in performance and, when used appropriately, it generates conditions for their forecast. The proposed approach has been tested on the industrial production index. The software product makes it possible to create maps of Russian Federation which illustrate the classes of the regions’ sustainability in terms of the industrial production index, which allows for assessing the reaction of the industry to the crises of 1998 and 2009. The main conclusion is based on the definition of the key trends in the development of regions that can be used by the authorities for administrative decisions in modeling strategies for the development of the Russian regions.Обеспечение устойчивого развития регионов, которое является приоритетом государственной социально-экономической политики, актуализирует необходимость создания инструментов оценки устойчивости региональных социально-экономических систем. Целью исследования является определение степени устойчивости региональной экономической системы («подчиненной» системы) относительно экономической системы страны («главной» системы). Исследование предполагает использование различных макроэкономических индикаторов, описывающих устойчивость региона, устойчивость предприятий и устойчивость домашних хозяйств. Результатом исследования стали разработка методического подхода к оценке устойчивости субъектов РФ относительно состояния экономической системы страны с использованием метода анализа рядов динамики макроэкономических индикаторов и классификация классов устойчивости региональной экономической системы на происходящие в экономике страны изменения. На основе этого метода разработан программный продукт, предназначенный для автоматизации процесса оценки и классификации устойчивости субъектов РФ. В статье описаны функциональные характеристики и возможности практического применения программного продукта. Программа обладает гибкостью настроек и позволяет оперативно выявлять основные тенденции в изменении показателей и при должном подходе создает условия для их прогнозирования. Предложенный подход апробирован на индексе промышленного производства. Программный продукт позволяет сформировать карты России, которые иллюстрируют классы устойчивости субъектов РФ по индексу промышленного производства и позволяют оценить реакцию промышленности регионов на кризисы 1998 и 2009 гг. Основный вывод строится на определении ключевых тенденций в развитии регионов, что может быть использовано органами власти для принятия управленческих решений при моделировании стратегий развития регионов РФ

The use of endovascular thrombectomy among the patients with acute ischemic stroke caused by the occlusion of large cerebral vessels

The effectiveness and complications of endovascular thrombectomy were analyzed. The obtained results show the reduction in mortality and disability among the patients after endovascular treatmen

Heat Capacity of PbS: Isotope Effects

In recent years, the availability of highly pure stable isotopes has made possible the investigation of the dependence of the physical properties of crystals, in particular semiconductors, on their isotopic composition. Following the investigation of the specific heat ($C_p$, $C_v$) of monatomic crystals such as diamond, silicon, and germanium, similar investigations have been undertaken for the tetrahedral diatomic systems ZnO and GaN (wurtzite structure), for which the effect of the mass of the cation differs from that of the anion. In this article we present measurements for a semiconductor with rock salt structure, namely lead sulfide. Because of the large difference in the atomic mass of both constituents ($M_{\rm Pb}$= 207.21 and ($M_{\rm S}$=32.06 a.m.u., for the natural isotopic abundance) the effects of varying the cation and that of the anion mass are very different for this canonical semiconductor. We compare the measured temperature dependence of $C_p \approx C_v$, and the corresponding derivatives with respect to ($M_{\rm Pb}$ and $M_{\rm S}$), with \textit{\textit{ab initio}} calculations based on the lattice dynamics obtained from the local density approximation (LDA) electronic band structure. Quantitative deviations between theory and experiment are attributed to the absence of spin-orbit interaction in the ABINIT program used for the electronic band structure calculations.Comment: 17 pages including 10 Fig

Dynamical Phases of Driven Vortices Interacting with Periodic Pinning

The finite temperature dynamical phases of vortices in films driven by a uniform force and interacting with the periodic pinning potential of a square lattice of columnar defects are investigated by Langevin dynamics simulations of a London model. Vortices driven along the [0,1] direction and at densities for which there are more vortices than columnar defects ($B>B_{\phi}$) are considered. At low temperatures, two new dynamical phases, elastic flow and plastic flow, and a sharp transition between them are identified and characterized according to the behavior of the vortex spatial order, velocity distribution and frequency-dependent velocity correlationComment: 4 pages with 4 figures. To be published in Phys. Rev. B Rapid Communication

On unconditionality of fractional Rademacher chaos in symmetric spaces

We study density estimates of an index set $\mathcal{A}$, under which unconditionality (or even a weaker property of the random unconditional divergence) of the corresponding Rademacher fractional chaos $\{r_{j_1}(t)\cdot r_{j_2}(t)\cdot\dots\cdot r_{j_d}(t)\}_{(j_1,j_2,\dots,j_d)\in \mathcal{A}}$ in a symmetric space $X$ implies its equivalence in $X$ to the canonical basis in $\ell_2$. In the special case of Orlicz spaces $L_M$, unconditionality of this system is also equivalent to the fact that a certain exponential Orlicz space embeds into $L_M$.Comment: to appear in Izv. RA

Modern view on the etiology, diagnosis and treatment of odontogenic maxillary sinusitis

The article illustrates modern aspects of the etiology, microbiology, clinical features, diagnostic modalities and treatment approaches for the management of odontogenic maxillary sinusitisВ статье рассмотрены современные аспекты этиологии, микробиологии, особенности клинических проявлений, методы диагностики и подходы к лечению одонтогенного верхнечелюстного синусит