Suchergebnisse

We present a generalization of a model that takes into account the magnetic disorder of paramagnetic host with interstitial point defects towards the case of alloy hosts. In the framework of disordered local moment approach combined with magnetic sampling method, we calculate solution enthalpy of carbon impurity in the paramagnetic fcc Fe-Mn steels. First, we use the magnetic special quasirandom structure (M-SQS) method for simulation of the paramagnetic state in Fe-Mn alloys without impurity. Here, Fe and Mn atoms are randomly distributed at the sites of a supercell following the chemical SQS method. Next, to calculate the energies for various magnetic realizations around the interstitial carbon impurity, we vary the position of the impurity within the SQS. Our calculations show that in alloys containing similar to 20 at. % Mn, the solution enthalpy of carbon reduces compared to the pure fcc-Fe. By analyzing the local and global effects of impurity on the properties of the matrix, we discuss various factors that could increase the carbon solubility in high-manganese austenitic steels. ; Funding Agencies|Russian Science FoundationRussian Science Foundation (RSF) [18-12-00492]; Swedish Research Council (VR)Swedish Research Council [2015-04391]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]

We present a detailed theoretical study of the electronic, magnetic, and structural properties of magnesiowustite Fe-1 Mg-x(x) O with x in the range between 0 and 0.875 using a fully charge self-consistent implementation of the density functional theory plus dynamical mean-field theory method. In particular, we compute the electronic structure and phase stability of the rocksalt B1-structured (Fe,Mg) O at high pressures relevant for the Earths lower mantle. We find that upon compression paramagnetic (Fe,Mg) O exhibits a spin-state transition of Fe2+ ions from a high-spin to low-spin (HS-LS) state which is accompanied by a collapse of local magnetic moments. The HS-LS transition results in a substantial drop in the lattice volume by about 4%-8%, implying a complex interplay between electronic and lattice degrees of freedom. Our results reveal a strong sensitivity of the calculated transition pressure P-tr. upon addition of Mg. While, for Fe-rich magnesiowustite with Mg x amp;lt; 0.5, Ptr. is about 80 GPa, for Mg x = 0.75 it drops to 52 GPa, i. e., by 35%. This behavior is accompanied by a substantial change in the spin transition range from 50 to 140 GPa in FeO to 30 to 90 GPa for x = 0.75. In addition, the calculated bulk modulus (in the HS state) is found to increase by similar to 12% from 142 GPa in FeO to 159 GPa in (Fe,Mg) O with Mg x = 0.875. We find that the pressure-induced HS-LS transition has different consequences for the electronic properties of the Fe-rich and -poor (Fe,Mg) O. For the Fe-rich (Fe,Mg) O, the transition is found to be accompanied by a Mott insulator to a (semi) metal phase transition. In contrast to that, for x amp;gt; 0.25, (Fe,Mg) O remains insulating up to the highest studied pressures, implying a Mott-insulator to band-insulator phase transition at the HS-LS transformation. ; Funding Agencies|Deutsche Forschungsgemeinschaft [Transregio TRR 80]; Ministry of Education and Science of the Russian Federation [K3-2016-027]; Russian Foundation for Basic Researches [16-02-00797]; Swedish Research Council (VR) [2015-04391]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]

The key direction of the state national policy of the Russian Federation is the successful social and cultural adaptation of foreign citizens in the Russian Federation, and their integration into Russian society. The article presents the results of a study of the value sphere of personality of young migrants from Central Asian countries. Both personal values and cultural values have been studied. The methodological framework of the study was the theoretical approach to the study of values by S. Schwartz and the cross-cultural approach to the study of the characteristics of different cultures by G. Hofstede. A comparative analysis of the value profiles of Russian youth and migrants from Kazakhstan, Uzbekistan, Tajikistan, Turkmenistan, and Kyrgyzstan was carried out. The empirical study found that the dominant values of young migrants are: kindness, safety, uncertainty avoidance, long-term orientation. When comparing the values of individual values, it was found that among young migrants all values are more pronounced than among young people from Russia. Comparing cultural values, it was found that uncertainty avoidance and masculinity among young migrants are lower than among young people from Russia. Taking into account these features of the value sphere of Central Asian migrants, as well as their connection with psychological acculturation strategies, the authors come to the conclusion that it is necessary to take into account the specifics of the value profile of migrants as a factor of psychological adaptation when providing socio-psychological assistance.

Considering Ti-V alloys with the body-centered cubic crystal lattice, a system with mechanical instability for Tirich alloys, we calculate their elastic properties using Projector Augmented Wave method and the exact muffin tin orbital method in a complete interval of V concentrations. The substitutional disorder is modeled using the special quasi-random structures technique and the coherent potential approximation. The efficiency and accuracy of the simulation techniques is analyzed, and a strategy for efficient high-throughput calculations of elastic properties of disordered alloys is proposed. Dependences of the single crystal elastic moduli on V concentration and a set ofmechanical characteristics of polycrystalline alloys are presented and discussed. The effect of V content on themechanical stabilization of the bcc Ti-V alloys is investigated. In agreement with experiment, we find that titanium-rich alloys are mechanically unstable, however the alloys becomemechanically stablewith increasing content of V in the system. We observe a nonlinear dependence of the alloys Youngs moduli in a vicinity of the mechanical stabilization and suggest that this effect can be used to design alloys with low values of the elastic moduli. (C) 2017 Elsevier Ltd. All rights reserved. ; Funding Agencies|Ministry of Education and Science of the Russian Federation [K2-2016-013, 211]; Swedish Research Council [2015-04391]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]

This paper examines the problems of changing the systems of the structures of governance in the first years of the existence of Soviet rule using the example of the armed forces, the redistribution of powers between them, the strengthening of the administrative influence of individual departments on the most important decisions in this area

The double magnetic proximity effect (MPE) in an Fe/Fe0.30V0.70 superlattice is studied by a direct measurement of the magnetization profile using polarized neutron reflectivity. The experimental magnetization profile is shown to qualitatively agree with a profile calculated using density functional theory. The profile is divided into a short range interfacial part and a long range tail. The interfacial part is explained by charge transfer and induced magnetization, while the tail is attributed to the inhomogeneous nature of the FeV alloy. The long range tail in the magnetization persists up to 170% above the intrinsic ordering temperature of the FeV alloy. The observed effects can be used to design systems with a direct exchange coupling between layers over long distances through a network of connected atoms. When combined with the recent advances in tuning and switching, the MPE with electric fields and currents, the results can be applied in spintronic devices. Published under license by AIP Publishing. ; Funding Agencies|Swedish Research Council; Ministry of Science and High Education of the Russian Federation in the framework of Increase Competitiveness Program of NUST (MISIS) [K2-2019-001, 211]; Swedish Government Strategic Research Areas in Materials Science on Functional Materials at Linkoping University [2009-00971]; Swedish e-Science Centre

The high-pressure synthesis of rhenium nitride pernitride with a crystal structure that is unusual for transition metal dinitrides and high values of hardness and bulk modulus attracted significant attention to this system. We investigate the thermodynamic and electronic properties of the P2(1)/c phase of ReN2 and compare them with two other polytypes, the C2/m and P4/mbm phases, suggested in the literature. Our calculations of the formation enthalpy at zero temperature show that the former phase is the most stable of the three up to a pressure p = 170 GPa, followed by the stabilization of the P4/mbm phase at higher pressure. The theoretical prediction is confirmed by diamond anvil cell synthesis of the P4/mbm ReN2 at approximate to 175 GPa. Considering the effects of finite temperature in the quasiharmonic approximation at p = 100 GPa we demonstrate that the P2(1)/c phase has the lowest free energy of formation at least up to 1000 K. Our analysis of the pressure dependence of the electronic structure of rhenium nitride pernitride shows the presence of two electronic topological transitions around 18 GPa, when the Fermi surface changes its topology due to the appearance of an electron pocket at the high-symmetry Y-2 point of the Brillouin zone while the disruption of the neck takes place slightly off from the Gamma-A line. ; Funding Agencies|Knut and Alice Wallenberg Foundation (Wallenberg Scholar Grant) [KAW-2018.0194]; Swedish Government Strategic Research Areas in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; SeRC, the Swedish Research Council (VR) [2019-05600]; VINN Excellence Center Functional Nanoscale Materials (FunMat-2) [201605156]; Russian Science FoundationRussian Science Foundation (RSF) [18-12-00492]; Swedish Research CouncilSwedish Research CouncilEuropean Commission [2016-07213]

PurposeThe purpose of the research is to develop scientific and methodological recommendations for indicative evaluation and systemic management of the professional and qualification potential of the digital society and to approbate them by the example of modern Russia.Design/methodology/approachThe authors use the proprietary algorithm of the creation and implementation of the professional and qualification potential of the digital society. Based on the new algorithm, a proprietary methodology of indicative evaluation of the professional and qualification potential of the digital society is developed.FindingsThe authors offer a complex of recommendations for systemic management of the professional and qualification potential of the digital society and their approbation by the example of Russia in 2020, which allow achieving high effectiveness of this management. The results of approbation of the proprietary methodology and recommendations by the example of Russia in 2020 showed that the professional and qualification potential of the digital society is rather high and well-balanced; it is normal but has perspectives for an increase. There is an imbalance, which is caused by the domination of the development of the education market over the market of labor and entrepreneurship. Based on this, managerial measures are recommended for the development of the professional and qualification potential of the digital society in Russia.Originality/valueThe offered algorithm sets the foundation of an expanded view of the studied process, according to which the professional and qualification potential of the digital society is not only limited by the educational market but also covers the labor market and entrepreneurship. This view is revolutionary for modern Russia. The advantages of the authors' methodology of indicative evaluation of the professional and qualification potential of the digital society include the usage of the complete set of qualitative and quantitative indicators, delimitation of indicators as to the stages of the algorithm, and the improved matrix for treatment of the results.