174 research outputs found

    Low temperature phase diagram of hydrogen at pressures up to 380 GPa. A possible metallic phase at 360 GPa and 200 K

    Full text link
    Two new phases of hydrogen have been discovered at room temperature in Ref.1: phase IV above 220 GPa and phase V above ~270 GPa. In the present work we have found a new phase VI at P~360 GPa and T<200 K. This phase is likely metallic as follows from the featureless Raman spectra, a strong drop in resistance, and absence of a photoconductive response. We studied hydrogen at low temperatures with the aid of Raman, infrared absorption, and electrical measurements at pressures up to 380 GPa, and have built a new phase diagram of hydrogen.Comment: 9 pages, 12 figure

    ANTI-CRISIS FACTORS OF COMPETITIVENESS OF SERVICE SECTOR ENTERPRISES

    Get PDF
    The transformation of the socio-economic conditions of the functioning of service enterprises caused by the spread of the COVID-19 pandemic and the resulting economic crisis, actualize the study of the possibilities of ensuring their competitiveness. The article gives the analysis of the genesis and development of the content of the category of enterprise competitiveness in the basic concepts of economic theory. The author proposes a definition of the competitiveness of a service enterprise. The paper analyses traditional basic factors of enterprise competitiveness as well as substantiates the anti-crisis factors of maintaining the competitive maintenance of a service sector enterprise in the context of the current economic crisis related to the COVID-19 pandemic, such as: digitalization of business and the process of providing services, customer focus, virtualization of the workforce, cybersecurity, and the use of opportunities of the state anti-crisis policy

    Conventional superconductivity at 203 K at high pressures

    Full text link
    A superconductor is a material that can conduct electricity with no resistance below its critical temperature (Tc). The highest Tc that has been achieved in cuprates1 is 133 K at ambient pressure2 and 164 K at high pressures3. As the nature of superconductivity in these materials has still not been explained, the prospects for a higher Tc are not clear. In contrast, the Bardeen-Cooper-Schrieffer (BCS) theory gives a guide for achieving high Tc and does not put bounds on Tc, all that is needed is a favorable combination of high frequency phonons, strong electron-phonon coupling, and a high density of states. These conditions can be fulfilled for metallic hydrogen and covalent compounds dominated by hydrogen4,5. Numerous calculations support this idea and predict Tc of 50-235 K for many hydrides6 but only moderate Tc=17 K has been observed experimentally7. Here we studied sulfur hydride8 where a Tc~80 K was predicted9. We found that it transforms to a metal at pressure ~90 GPa. With cooling superconductivity was found deduced from a sharp drop of the resistivity to zero and a decrease of Tc with magnetic field. The pronounce isotope shift of Tc in D2S is evidence of an electron-phonon mechanism of superconductivity that is consistent with the BCS scenario. The superconductivity has been confirmed by magnetic susceptibility measurements with Tc=203K. The high Tc superconductivity most likely is due to H3S which is formed from H2S under its decomposition under pressure. Even higher Tc, room temperature superconductivity, can be expected in other hydrogen-based materials since hydrogen atoms provide the high frequency phonon modes as well as the strong electron-phonon coupling

    Constitutional-Legal and Political Responsibility of Political Parties in the Russian Federation to Electors

    Get PDF
    Analysis of the legal and political responsibility of officials of a democratically elected state to their constituents. The subjects of the above responsibility may be elected officials of the legislative (representative) bodies of state power. The constitutional status of elected persons exercising public authority on behalf of individuals suggests the possibility of terminating their powers as sanctions only on the basis of the rules of law enshrined in the relevant acts and establishing clear reasons and procedures for liability. The current legislation of the Russian Federation provides for various types of constitutional and legal sanctions

    Mentorship in Higher Education: a Concept, a Model and Development Prospects

    Get PDF
    The article examines the mentorship development in higher education. The need for a scientific reconsideration of the conceptual framework of mentorship in modern conditions, as well as its important practical significance for adapting students, improving the quality of education and professional activity are forming the relevance of this topic. The purpose of the article is to develop the concept of mentorship, to design a model and to plan the mentoring in higher education. An interdisciplinary approach was used to determine the essence of mentorship (consideration of the category in Psychology and Sociology, Pedagogy, Management), a model of mentorship in higher education has been developed with a structural-system analysis, as well as with graphical and statistical methods. The scientific novelty of the article is the development of the conceptual framework of mentoring and applied aspects of its implementation in higher education in Russia. The essential elements of mentorship were identified and considered, namely: the concept and approaches, purpose and objectives, principles and functions. The types of mentorship in higher education were classified according to key criteria: the number of mentees, formalization, period of interaction, method of implementation, direction of interaction, purpose. The main principles of mentoring in higher education are specified. A model of mentoring in higher education was proposed. A systematic analysis of successful practices and mentoring programs in higher education in Russia was carried out. The problems and prospects for mentorship development in modern conditions were identified. The practical significance of the study lies in the possibility of using conceptual developments in the formation and development of the legal framework for the implementation of mentoring, as well as the development and implementation of a mentoring model in higher education institutions
    corecore