Conventional superconductivity at 203 K at high pressures

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

РЕШЕНИЕ 3D-ЗАДАЧИ КОМПЬЮТЕРНОЙ ТОМОГРАФИИ ПО ИЗВЕСТНЫМ ТОМОГРАММАМ НА СИСТЕМЕ ПРОИЗВОЛЬНЫХ ПЛОСКОСТЕЙ

The article is based on restoration method for the internal structure of a three-dimensional body using polynomial interflatation based on known tomograms (traces) lying on a system of arbitrary planes, which is a generalization of the method of body restoration with its known tomograms on a system of three groups of parallel planes. A definition of tomograms in the mathematical sense has been provided and the algorithm of transition of tomogram images into the functional dependence has been outlined.Theorems on interflatation properties and errors of the built operator have been formulated and proved. A test case for the construction of the interflatation operator for the quadratic function has been demonstrated, and the computational experiment involved the development of a number of programs in MathCad. The experiment has provided visualization results for an exact solution and a solution obtained experimentally for the case when the exact function is known. It has been shown that the constructed structure approximates this function exactly, which is not the case of classic interpolation operators.The suggested method makes it possible to solve the problem of three-dimensional computer tomography for a fundamentally new data collection scheme. For example, it permits the use of the fan scheme for data collection in each of the planes in which the tomograms lie. Построена и исследована математическая модель двухмерной компьютерной томографии с использованием интерфлетации функций трех переменных по известным томограммам исследуемого тела. Дается понятие томограммы в математическом смысле как след от функции трех переменных на заданной плоскости, построен алгоритм перевода изображения томограмм в функциональную зависимость, аргументами которой являются номер рисунка и координаты точек. Это дает возможность работать с томограммами как с функциями, то есть позволяет по номеру рисунка получать его изображения и выделять компонент цвета в указанной точке рисунка.Строится и исследуется оператор интерфлетации функции трех переменных по известным следам функции на системе произвольных плоскостей. Приводится теорема об общем виде погрешности приближения функции трех переменных, построенных оператором интерфлетации в интегральном виде. Также приведена оценка неустранимой погрешности экспериментальных данных. Продемонстрирован пример восстановления функции трех переменных с помощью оператора интерфлетации по ее известным следам на системе произвольно расположенных плоскостей. Проведен численный эксперимент для заранее заданного тела, для этого был разработан комплекс программ в системе компьютерной математики MathCad. Численный эксперимент дает результаты визуализации точного решения и решения, полученного экспериментально, для случая, когда известна точная функция.Предложенный метод восстановления существенно отличается от существующих тем, что в нем может проводиться обработка томограмм, которые не лежат в параллельных плоскостях (например, в простейшем случае томограммы могут располагаться в системе трех групп плоскостей, параллельных координатным плоскостям)

Experience in the implementation of palliative, combined and expanded operations in emergency surgery of gastric cancer

В статье рассмотрен опыт выполнения неотложных абдоминальных онкохирургических операций, выполненных на базе отделения абдоминальной онкологии за период 2012–2014 гг. Всего в исследование включен 51 больной, которым выполнены ургентные и срочные плановые операции по поводу осложнений рака желудка. Всего выполнено 27 паллиативных, 6 расширенных, 15 комбинированных операций. По-настоящему ургентных было только 2, во время которых были выполнены в обоих случаях гастрэктомии со спленэктомией без выполнения расширенных лимфодиссекций. Сделан вывод, что выполнение радикальных операций не увеличивает летальность при осложненном течении рака желудка. В мировой ургентной медицине используются различные классификации срочных, в т. ч. неотложных операций, наиболее унифицированной из которых является классификация WSES-2013. Традиционное, “отечественное” распределение неотложных онкологических операций на ургентные/срочные/плановые или даже чаще на ургентные/ плановые является устоявшимся и необходимым. Индивидуализация подхода к каждой ургентной операции, как и вообще тенденция к индивидуализации в онкологии, представляется неотъемлемым мотивом грядущих методологических перемен в неотложной онкохирургии.The article describes the experience of urgent oncosurgical abdominal operations carried out on the basis of Abdominal Oncology Department for the period 2012–2014 years. In total, the study included 51 patients, who underwent emergent and urgent elective surgery for complications of stomach cancer. Total holds 27 palliative, 6 advanced, 15 combined operations. The really emergent were only 2, during which were performed in both cases gastrectomy with splenectomy without performing extended lymph node dissection. It was concluded that the implementation of radical surgery does not increase mortality rate in complicated gastric cancer. In the world of emergent medicine there are used different classification approaches, including emergency operations, most of which is a unified classification WSES-2013. The traditional distribution of urgent cancer operations in urgent / emergency / routine or even more frequently in the urgent / routine is well established and necessary. Personalisation approach to each of urgent surgical case, as well as general trend towards individualization in oncology seems to be inherent motive of future methodological changes in emergency cancer surgery

колективна монографія

Кримінальний процесуальний кодекс 2012 року: ідеологія та практика правозастосування: колективна монографія / за заг. ред. Ю. П. Аленіна ; відпов. за вип. І. В. Гловюк. - Одеса : Видавничий дім «Гельветика», 2018. - 1148 с

Pyridinium bis(pyridine-jN)tetrakis(thiocyanato-cyanato-jN)ferrate(III)

In the title compound, (C5H6N)[Fe(NCS)4(C5H5N)2], the FeIII ion is coordinated by four thiocyanate N atoms and two pyridine N atoms in a trans arrangement, forming an FeN6 polyhedron with a slightly distorted octahedral geometry. Charge balance is achieved by one pyridinium cation bound to the complex anion via N—HS hydrogen bonding. The asymmetric unit consists of one FeIII cation, four thiocyanate anions, two coordinated pyridine molecules and one pyridinium cation. The structure exhibits – interactions between pyridine rings [centroid–centroid distances = 3.7267 (2), 3.7811 (2) and 3.8924 (2) A˚ ]. The N atom and a neighboring C atom of the pyridinium cation are statistically disordered with an occupancy ratio of 0.58 (2):0.42 (2).peerReviewe

Photoinduced hole transfer from tris(bipyridine)ruthenium dye to a high-valent iron-based water oxidation catalyst

An efficient water oxidation system is a prerequisite for developing solar energy conversion devices. Using advanced time-resolved spectroscopy, we study the initial catalytic relevant electron transfer events in the light-driven water oxidation system utilizing [Ru(bpy)(3)](2+) (bpy = 2,2 '-bipyridine) as a light harvester, persulfate as a sacrificial electron acceptor, and a high-valent iron clathrochelate complex as a catalyst. Upon irradiation by visible light, the excited state of the ruthenium dye is quenched by persulfate to afford a [Ru(bpy)(3)](3+)/SO4- pair, showing a cage escape yield up to 75%. This is followed by the subsequent fast hole transfer from [Ru(bpy)(3)](3+) to the Fe-IV catalyst to give the long-lived Fe-V intermediate in aqueous solution. In the presence of excess photosensitizer, this process exhibits pseudo-first order kinetics with respect to the catalyst with a rate constant of 3.2(1) x 10(10) s(-1). Consequently, efficient hole scavenging activity of the high-valent iron complex is proposed to explain its high catalytic performance for water oxidation

Copper-containing hybrid compounds based on extremely rare [V2Mo6O26]6- POM as water oxidation catalysts

Herein, we report two approaches to the synthesis of heterometallic complexes (NH4)(2n)(H(2)en)(n){[Cu(en)(2)][alpha-V2Mo6O26]}center dot 4nH(2)O (1), (NH4)(2){[Cu(dien)(H2O)](2)[alpha-V2Mo6O26]}center dot 5H(2)O (2) and (NH4)(2){[Cu(dien)(H2O)](2)[alpha-V2Mo6O26]}center dot 8H(2)O (3) that have been employed in homogeneous photochemical oxidation of water to dioxygen. In these hybrid metalorganic-inorganic compounds, copper-containing complex fragments are covalently bound to the rare vanadium-disubstituted alpha-octamolybdate cluster. They exhibit variable catalytic activity controlled by the local coordination environment of copper reaching a notably high turnover frequency of 0.24 s(-1) for 3 in combination with a relatively low water oxidation overpotential. The complexes have been also used as precursors for the preparation of mixed oxide phases that have proven to be active heterogeneous water oxidation catalysts

The Condorcet paradox revisited

We analyze the Condorcet paradox within a strategic bargaining model with majority voting, exogenous recognition probabilities, and no discounting. Stationary subgame perfect equilibria (SSPE) exist whenever the geometric mean of the players' risk coefficients, ratios of utility differences between alternatives, is at most one. SSPEs ensure agreement within finite expected time. For generic parameter values, SSPEs are unique and exclude Condorcet cycles. In an SSPE, at least two players propose their best alternative and at most one player proposes his middle alternative with positive probability. Players never reject best alternatives, may reject middle alternatives with positive probability, and reject worst alternatives. Recognition probabilities represent bargaining power and drive expected delay. Irrespective of utilities, no delay occurs for suitable distributions of bargaining power, whereas expected delay goes to infinity in the limit where one player holds all bargaining power. Contrary to the case with unanimous approval, a player benefits from an increase in his risk aversion