A new large N phase transition in YM2

Inspired by the interpretation of two dimensional Yang-Mills theory on a cylinder as a random walk on the gauge group, we point out the existence of a large N transition which is the gauge theory analogue of the cutoff transition in random walks. The transition occurs in the strong coupling region, with the 't Hooft coupling scaling as alpha*log(N), at a critical value of alpha (alpha = 4 on the sphere). The two phases below and above the transition are studied in detail. The effective number of degrees of freedom and the free energy are found to be proportional to N^(2-alpha/2) below the transition and to vanish altogether above it. The expectation value of a Wilson loop is calculated to the leading order and found to coincide in both phases with the strong coupling value.Comment: 23 pages, 3 figure

The Kazakov-Migdal Model as a High Temperature Lattice Gauge Theory

We show that the Kazakov-Migdal (K-M) induced gauge model in $d$ dimensions describes the high temperature limit of ordinary lattice gauge theories in $d+1$ dimensions. The matter fields are related to the Polyakov loops, while the spatial gauge variables become the gauge fields of the K-M model. This interpretation of the K-M model is in agreement with some recent results in high temperature lattice QCD.Comment: 12 pages, plain latex, DFTT 71/9

Asymptotic Learning Curve and Renormalizable Condition in Statistical Learning Theory

Bayes statistics and statistical physics have the common mathematical structure, where the log likelihood function corresponds to the random Hamiltonian. Recently, it was discovered that the asymptotic learning curves in Bayes estimation are subject to a universal law, even if the log likelihood function can not be approximated by any quadratic form. However, it is left unknown what mathematical property ensures such a universal law. In this paper, we define a renormalizable condition of the statistical estimation problem, and show that, under such a condition, the asymptotic learning curves are ensured to be subject to the universal law, even if the true distribution is unrealizable and singular for a statistical model. Also we study a nonrenormalizable case, in which the learning curves have the different asymptotic behaviors from the universal law

Current control in the competence approach

This paper proposes a method of monitoring the knowledge-based test technologies and allows monitoring of formation of partial competencies. The proposed method is illustrated by the example of the course of computer scienceВ работе предлагается методика текущего контроля знаний, основанная на тестовых технологиях и позволяющая осуществлять частичный мониторинг сформированности компетенций. Предлагаемая методика иллюстрируется примером из курса информатик

Study of the results of use on the academic performance of the first-year students of applied mathematics and computer science

The paper discusses the influence of such factors as the results of the Unified State Examination on the academic performance of the first-year students throughout the school year. It uses the technique of grouping students according to their level of performanceВ работе рассматривается вопрос о влиянии такого фактора как результаты единого государственного экзамена на успеваемость студентов-первокурсников в течение всего учебного года. При этом используется методика группировки студентов по уровню их успеваемост

Thermodynamic basis of intragroup separation of Pr and Nd in the chloride melts employing liquid gallium-tin electrodes

Объектом исследования являются жидкометаллические двухфазные (Ж+ИМС) и гомогенные сплавы празеодима и неодима с эвтектическим расплавом Ga-Sn. Цель работы – определение термодинамических характеристик празеодима и неодима в эвтектических сплавах Ga-Sn в температурном диапазоне 573 1073 К. В отчете проведен анализ литературных данных об активности, коэффициентах активности и растворимости празеодима и неодима, в индивидуальных галлии и олове. Отдельная глава посвящена анализу литературных данных о термодинамических характеристиках празеодима и неодима в сплавах с индием и висмутом, так как в изучаемом температурном интервале эти сплавы могут быть использованы в качестве электродов сравнения.Objects of the study are two-phase and homogeneous liquid alloys of praseodymium and neodymium with Ga-Sn eutectic melt. The purpose of investigation is determination of thermodynamic properties of praseodymium and neodymium in the eutectic Ga-Sn alloys at the temperature range 573 1073 K. The report analyzed the published data on the activity, activity coefficient and solubility of praseodymium and neodymium, in gallium and tin. Separate chapter contains analysis of published data on the thermodynamic characteristics of alloys of praseodymium and neodymium with indium and bismuth because such alloys are suitable as reference electrodes at investigated temperatures.Программа развития УрФУ на 2013 год (п.1.2.2.3

Morphological record of pedogenesis and landscape evolution in the upper quaternary pedosediments within the upper Volga river basin

The morphological record of pedogenesis (mostly at a micromorphological scale) and the features of paleosols developed at the northern geographical extremity of the MIS3 paleopedoshpere (including the Bryansk fossil soils) are described. The profiles of the MIS3 paleosols (dark humic gley and peaty gley with the14С-age around 29-50 cal kyr BP) are located within the periglacial zone in the centre of the Russian Plain (56.7°-58.5° N) within the Upper Volga drainage basin. An assemblage of stable micromorphological features of paleosols studied includes the following: 1) ferruginous nodules and other pedofeatures, occasionally fragmented; 2) concentration (separation) of sand grains within certain microzones; 3) inclusions of raw organic matter, often deformed and oriented to different degrees within the matrix. Despite being buried for a long time period and superimposed by the Holocene pedogenetic processes (clay illuviation), the paleosols preserve some features of short-term (101-102 yr) and medium-term (102-103-4 yr) elementary pedogenetic processes (EPP). The short-term EPP include gleying, structure forming and cryogenic processes. The medium-term EPP include humus formation, peat formation and organic matter accumulation. A hypothesis of cryogenic formation of the paleosols studied is substantiated. Only an almost impermeable layer of permafrost could cause water-logging and gleying in these geological and geomorphological conditions

Печатная сверхширокополосная антенна с узкими полосами запирания

The ultra-wideband (UWB) monopole antennas are designed to provide the impedance band-width of the wideband response from 2.5 to 12 GHz. To achieve single-, dual-, or triple-band notched characteristics at desirable frequencies, the electric ring resonator incorporated into the CPW feed line is used in the planar configuration of the UWB antenna. The notched frequency bands are con-trolled by dimensions of the ERR structure. The results of simulations and measurements are in good agreement.Разработаны сверхширокополосные (СШП) антенны, предназначенные для работы в диапазоне частот 2.5...12 ГГц, имеющие полосно-заграждающую характеристику: СШП-антенна с одной, двумя и тремя узкими полосами запирания. Продемонстрировано, что использование электрического кольцевого резонатора в составе СШП-антенны позволяет легко реализовать указанные полосы на требуемых частотах. Результаты измерений прототипов СШП-антенн с одной и двумя полосами запирания, изготовленных по технологии производства печатных плат, хорошо согласуются с расчетными данными

Solid state amorphization in a thin Fe-Si-Mg-O surface film triggered by the reduction of elements from oxides in the temperature range of the α-γ transformation

The study of the processes occurring in the surface layer of the MgO coated commercial alloy Fe-3%Si-0.5%Cu (grain oriented electrical steel) demonstrated that the amorphous phase in the form of a Fe-based solid solution is formed during continuous heating in the 95%N2 + 5%H2 atmosphere. For the purposes of this study, the following methods were used: non-ambient XRD at 20 –1060°C with heating and cooling at a rate of 0.5 dps, layer-by-layer chemical analysis performed by a glow discharge analyzer, scanning electron microscopy and energy dispersive X-ray spectroscopy. ThermoCalc software was used to calculate the potential phase equilibrium states. The amorphous phase was formed in the α → γ transformation temperature range, when the heating rates were altered in the surface layer of 1 µm initially consisted of a solid α-Fe-based solution with ~1– 2 wt.% Si with (MgFe)2 SiO4, (MgFe)O, SiO2 oxide inclusions. We suppose that (MgFe)2 SiO4 oxides are partly reduced by H2 to Mg2 Si molecular complexes, which become solid solutions in the temperature range of the metastability of the α-Fe crystal lattice with subsequent amorphization as an alternative to the α → γ transition. The amorphous state is obtained at 920 – 960°C and is retained both at subsequent heating (to 1060°C) and cooling (to 20°С), which is super-stable compared to the established metallic glasses. The composition of the amorphous phase can be described by the formula Fe89.5 Si6 Mg4 Cu0.5. © 2020, Institute for Metals Superplasticity Problems of Russian Academy of Sciences. All rights reserved.Russian Foundation for Basic Research, RFBR: 20‑08‑00332Ministry of Education and Science of the Russian Federation, Minobrnauka: 11.1465.2014/K.Acknowledgements. This study was conducted using equipment provided by the Laboratory of Structural Analysis Techniques and Materials and Nanomaterials Properties of CKP Ural Federal University. The study was financially supported by Government Decree No. 211 of the Russian Federation, Contract No. 02. A03.21.0006 and within the framework of the state task issued by the Ministry of Education and Science of the Russian Federation, project No. 11.1465.2014/K. The reported study was funded by RFBR, project number 20‑08‑00332