57 research outputs found

    Mechanisms of Postsynthesis Doping of Boron Nitride Nanostructures with Carbon from First-Principles Simulations

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    Electron-beam-mediated postsynthesis doping of boron-nitride nanostructures with carbon atoms [Nature (London) 464, 571 (2010); J. Am. Chem. Soc. 132, 13 692 (2010)] was recently demonstrated, thus opening a new way to control the electronic properties of these systems. Using density-functional theory static and dynamic calculations, we show that the substitution process is governed not only by the response of such systems to irradiation, but also by the energetics of the atomic configurations, especially when the system is electrically charged. We suggest using spatially localized electron irradiation for making carbon islands and ribbons embedded into BN sheets. We further study the magnetic and electronic properties of such hybrid nanostructures and show that triangular carbon islands embedded into BN sheets possess magnetic moments, which can be switched on and off by electrically charging the structure.Peer reviewe

    Charged Point Defects in the Flatland: Accurate Formation Energy Calculations in Two-Dimensional Materials

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    Impurities and defects frequently govern materials properties, with the most prominent example being the doping of bulk semiconductors where a minute amount of foreign atoms can be responsible for the operation of the electronic devices. Several computational schemes based on a supercell approach have been developed to get insights into types and equilibrium concentrations of point defects, which successfully work in bulk materials. Here, we show that many of these schemes cannot directly be applied to two-dimensional (2D) systems, as formation energies of charged point defects are dominated by large spurious electrostatic interactions between defects in inhomogeneous environments. We suggest two approaches that solve this problem and give accurate formation energies of charged defects in 2D systems in the dilute limit. Our methods, which are applicable to all kinds of charged defects in any 2D system, are benchmarked for impurities in technologically important h-BN and MoS2 2D materials, and they are found to perform equally well for substitutional and adatom impurities.Peer reviewe

    On the Factors Influencing Resilience Personalities of Practical Psychologists

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    Рассматривается жизнестойкость практических психологов в контексте толерантности к неопределенности и в зависимости от особенностей профессионального самоотношения.The author considers the resilience of practical psychologists in the context of tolerance to uncertainty and depending on the character­istics of professional self-attitude

    SEPARATION OF RADIUM – 228 FROM THORIUM-232 USING MnO2 - MN202 SORBENT

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    The work is devoted to the study of the sorption of radium-228 on the microporous ad-sorbent MN202, on the surface of which a layer of manganese dioxide is deposited. As a result of the study, a solution of radium-228 was obtained, purified from radium-224 and its decay products

    4D FLOW МРТ в оценке диастолического кровотока в левом желудочке у пациентов с гипертрофической кардиомиопатией

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    Objective. To assess phase-contrast MRI in the evaluation of left ventricular hemodynamics changes in various forms of hypertrophic cardiomyopathy.Materials and methods. 11 patients were examined: without pathology of the cardiovascular system (n = 3), with apical (n = 3), diffuse-septal (n = 2) and focal-basal (n = 3) types of hypertrophic cardiomyopathy. All patients underwent MRI of the heart with an additional phase-contrast sequence of the left ventricular area. Postprocessing carried out in the 4D FLOW application (Siemens).Results. Data were obtained on the geometry and dynamics of vortex diastolic flows in the left ventricular of all patients. In patients with hypertrophic cardiomyopathy, an increase in the distance to the center of the vortex and a decrease in the normalized area and peak velocity of the vortex is determined. The diffuse-septal type is characterized by a minimal vortex peak velocity; apical type - by the maximum vortex sphericity index. For patients with a focalbasal type of hypertrophic cardiomyopathy the maximum changes in blood flow are determined in late diastole (absence of vortexes).Conclusion. 4D FLOW Phase-contrast MRI allows identifying and assessing LV vortical flow. Quantitative analysis can be used to characterize the remodeling of LV blood flow of various types of hypertrophic cardiomyopathy.Цель исследования: оценить изменения гемодинамики левого желудочка с помощью фазово-контрастной МРТ у пациентов с различными формами гипертрофической кардиомиопатии.Материал и методы. Обследовано 11 пациентов: без патологии сердечно-сосудистой системы (n = 3), с апикальной (n = 3), диффузно-септальной (n = 2) и фокально-базальной (n = 3) формами гипертрофической кардиомиопатии. Всем пациентам выполнено МРТ-исследование сердца с дополнительной фазовоконтрастной последовательностью области левого желудочка. Постпроцессорная обработка проведена в приложении 4D FLOW (Siemens).Результаты. Получены данные о геометрии и динамике вихревых диастолических потоков в левом желудочке у всех пациентов. У пациентов определяется апикальное смещение вортекса, уменьшение нормализованной площади и пиковой скорости вортекса. Диффузно-септальная форма характеризуется минимальной скоростью вихревого потока, апикальная форма – максимальным индексом сферичности вортекса. Для пациентов с фокально-базальной формой максимальные изменения кровотока определяются в позднюю диастолу (отсутствие вортексов)Заключение. Метод 4D FLOW фазово-контрастной МРТ позволяет выявить и оценивать изменения диастолических вихревых потоков в левом желудочке. Количественный анализ данных можно использовать для характеристики ремоделирования кровотока в левом желудочке при различных типах гипертрофической кардиомиопатии

    2020 Clinical practice guidelines for Hypertrophic cardiomyopathy

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    Russian Society of Cardiology (RSC)With the participation: Russian Association of Cardiovascular SurgeonsEndorsed by: Research and Practical Council of the Ministry of Health of the Russian Federation Task Force: Gabrusenko S.A. (Chairman), Gudkova A.Ya.* (Chairman), Koziolova N.A. (Chairman), Alexandrova S.A., Berseneva M.I., Gordeev M.L., Dzemeshkevich S.L., Zaklyazminskaya E.V., Irtyuga O.B., Kaplunova V.Yu., Kostareva A.A., Krutikov A.N., Malenkov D.A., Novikova T.N., Saidova M.A., Sanakoev M.K., Stukalova O.V

    Psychological support of fly-in/fly-out labour for construction companies working in Far North

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    The paper focuses on the methods of selecting personnel for work shifts at the construction enterprise in the extreme conditions of the Far North. The paper attempts to suggest ways of staff psychological support during the selection of candidates. Methods and means of psychological support of the adaptation period of shift workersare proposed, based on the analysis of changes in the level of efficiency and the psycho-functional state of the staff when working shifts in the severe northern region. Further recommendations are given on the application of methods to improve the process of adaptation to extraordinary living conditions at various stages of a shift work period. The paper investigates and determines the dependence of the efficiency of personnel on such indicators as the time of adaptation to shift work conditions with intense physical exertion, temperament, physical qualities, psycho-emotional state and age of candidates. The methods of teaching personnel self-control skills are proposed, the main components of psychological support for staff adaptation are highlighted. In conclusions, the main risk groups when selecting candidates for senior positions of personnel working shifts in the conditions of the Far North are identified

    APPLICATION PRACTICE OF THE ORDER OF THE RUSSIAN MINISTRY OF HEALTH IN THE ORDER OF THE ORGANIZATION OF SANATORIUM TREATMENT (on the example of sanatorium for children)

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    The analysis of recommendations of the Russian Ministry of Health about regular provid-ing the sanatorium organizations is provided to publications, reducing standard number of average and associate health workers is shown
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