To the question of the interpolation of the phase equilibrium curves for the hydrates of methane and carbon dioxide

The experimental data base was developed. This database includes 200 points of the phase equilibrium curve of methane hydrate, as well as more than 300 experimental points for carbon dioxide hydrate. This database is based on the work of a large number of researchers. Taking into account the experimental data, empirical formulas are constructed for determining the equilibrium parameters of the methane and carbon dioxide hydrates, as well as the equilibrium curve of “liquid carbon dioxide – gaseous carbon dioxide”

Внешнеэкономический потенциал Украины в Черноморском регионе

The article deals with the historical background for the creation of the Silk Road. Based on the research conducted the article defines the routes of cargo transportation of the ancient and modern Silk Road and analyzes the background for creation of the "New Economic Belt - The Great Silk Road". This article briefly describes the perspectives of the Silk Road Development Initiative to facilitate the trade and investments to Central Asia and other countries of “The Great Silk Road”. The author states that the successful implementation of the project of building the "New Silk Road" will, in some way, even mark the beginning of the new era, the era of active expansion of Asia into young and exuberant Europe. One of the main goals of the "One Belt - One Road" initiative is the development of China's central and western regions. The Chinese initiative is more inwardly-directed than outwardly-directed towards the Chinese economy and Chinese society. The paper has analysed the background of development of the geo-economical code of Ukraine and has studied the modern trade relationship between Ukraine and China. The author has researched the possibilities of using the potential of Ukraine to implement the conceptual provisions of the project "One Belt, One Road" and has paid much attention to the main goals of this project. Author states that as the potential for economic cooperation between states is closely related to the infrastructure projects, Ukraine should take measures aimed at developing its own infrastructure capacity. The article notes that if China's plan concerning “The Great Silk Road” is successfully implemented (which anticipates China's direct access to Europe through Central Asia and the Caucasus), Ukraine will play a brand new geopolitical role of the "first European country of the Silk Road."В рамках статьи рассмотрены исторические предпосылки к созданию Великого шелкового пути. На основе проведённого исследования в статье проанализированы направления грузоперевозок исторического и современного Шелкового пути, а также предпосылки создания «Нового экономического пояса - Великий шелковый путь». В этой статье кратко описываются перспективы Инициативы по развитию Шелкового пути для содействия торговле и инвестициям в Центральной Азии и других странах «Великого шелкового пути». Автор утверждает, что успешная реализация проекта строительства «Нового шелкового пути» ознаменует в какой-то мере даже новую эпоху — эпоху активной экспансии Европы «молодой и полной сил» Азией. Одна из главных целей инициативы «Один пояс — одна дорога» — это развитие центральных и западных регионов Китая. Китайская инициатива направлена не столько вовне, сколько внутрь самой китайской экономики и китайского общества. В работе анализируются предпосылки развития геоэкономического кода Украины и исследуются современные торговые отношения между Украиной и Китаем. Автором были исследованы возможности использование потенциала Украины для реализации концептуальных положений проекта «Один пояс, один путь», а также уделено значительное внимание главным целям инициативы данного проекта. Автор утверждает, что поскольку потенциал экономического сотрудничества между государствами во многом касается инфраструктурных проектов, Украине следует принимать меры, направленные на развитие собственной инфраструктурной способности. В статье отмечается, что если план Китая касательно «Великого шелкового пути» будет успешно реализован (который предполагает прямой доступ Китая к Европе через Центральную Азию и Кавказ), Украина будет играть совершенно новую геополитическую роль «первой европейской страны Шелкового пути”

Spin-density-wave instability in graphene doped near the van Hove singularity

We study the instability of the metallic state towards the formation of a new ground state in graphene doped near the van Hove singularity. The system is described by the Hubbard model and a field theoretical approach is used to calculate the charge and spin susceptibility. We find that for repulsive interactions, within the random phase approximation, there is a competition between ferromagnetism and spin-density wave (SDW). It turns out that a SDW with a triangular geometry is more favorable when the Hubbard parameter is above the critical value U_c(T), which depends on the temperature T, even if there are small variations in the doping. Our results can be verified by ARPES or neutron scattering experiments in highly doped graphene.Comment: 5 pages, 5 figures, 1 tabl

Analysis of causality Bayesian network usage for data-mining purposes

Робота присвячена використанню мереж Байєса для побудови причинно-наслідкової мережі ідентифікації хворих.The paper is devoted to the use of Bayesian networks for constructing a cause-and-effect identification network for patients.Работа посвящена использованию сетей Байеса для построения причинно-следственной сети для идентификации больных раком

Fabrication of Nanosize Films on the Base of Scutterudite CoSb₃ for Thermoelectric Devices

The work is concerned with ascertainment of the regularities for thermostimulated formation of the phase composition and structure of CoSb₃-scutterudite-based films deposited by the vacuum condensation method as well as the effect of the nanoscale factor on their thermoelectric properties.Работа посвящена установлению закономерностей термостимулирован-ного формирования фазового состава и структуры плёнок на основе скуттерудита CoSb₃, осаждённых методом вакуумной конденсации, а также влияния фактора наноразмерности на их термоэлектрические свойства.Роботу присвячено встановленню закономірностей термостимульованого формування фазового складу та структури плівок на основі скутерудиту CoSb₃, осаджених методом вакуумної конденсації, а також впливу чинника нанорозмірности на їхні термоелектричні властивості

Development of the algorithm for aircraft control at inaccurate measurement of the state vector and variable accuracy parameter

A parametric method of the synthesis of control in the closed circuit, taking into account explicitly generalized error of the inertial module, is presented. The law of control in the form of analytical formulas is typically assigned to the control program and does not change during flight of an unmanned aerial vehicle. This decreases the capabilities of the autonomous flight control system to overcome control errors, which occur for various reasons. To verify assumptions about a possibility of improving the accuracy of an aerial vehicle control by the data of the strapdown inertial navigation system on a certain time interval of autonomous operation, the calculation experiment was conducted with the use of the developed software complex, simulating operation of the automatic flight control system. Parametrization of the law of control is considered as the main contribution (the outcome). Introduction of the parameter made it possible to decrease a negative impact of measurement errors and other disturbing factors on accuracy of reaching by the point of flight destination. Through computer modeling, it was shown that it is possible to decrease the impact of a generalized measurement error on generation of values of control functions by changing the value of the parameter. Analytical expressions for the estimation of accuracy of automatic control at the known generalized error of the inertial module and limited disturbing influences were obtained. After analyzing the influence of these factors on accuracy of the object control, a set of recommendations on selection of a variable parameter of synthesis of control depending on precision level of the sensors, used in the inertial module of measuring sensors, was generated.Розглянуто розв’язання термінальної задачі управління та синтезований параметризований закон управління в аналітичному вигляді, який залежить від змінного параметра глибини прогнозу. Досліджено особливості впливу величини параметра управління на точність досягнення кінцевої точки, дані рекомендації з вибору параметра для нівелювання помилки інерційних вимірювань. Синтез управління здійснюється методом переслідування ведучої точки за інформацією, отриманою інтегруванням вимірювань фактичного прискорення і містить помилку, характерну для акселерометрів

Transport properties of a quantum wire: the role of extended time-dependent impurities

We study the transport properties of a quantum wire, described by the Tomonaga-Luttinger model, in the presence of a backscattering potential provided by several extended time-dependent impurities (barriers). Employing the B\" uttiker-Landauer approach, we first consider the scattering of noninteracting electrons ($g=1$) by a rectangular-like barrier and find an exact solution for the backscattering current, as well as a perturbative solution for a weak static potential with an arbitrary shape. We then include electron-electron interactions and use the Keldysh formalism combined with the bosonization technique to study oscillating extended barriers. We show that the backscattering current off time-dependent impurities can be expressed in terms of the current for the corresponding static barrier. Then we determine the backscattering current for a static extended potential, which, in the limit of noninteracting electrons ($g=1$), coincides with the result obtained using the B\" uttiker-Landauer formalism. In particular, we find that the conductance can be increased beyond its quantized value in the whole range of repulsive interactions $0<g<1$ already in the case of a single oscillating extended impurity, in contrast %contrary to the case of a point-like impurity, where this phenomenon occurs only for $0<g<1/2$.Comment: 9 pages, 5 figure

Coupled quantum wires

We study a set of crossed 1D systems, which are coupled with each other via tunnelling at the crossings. We begin with the simplest case with no electron-electron interactions and find that besides the expected level splitting, bound states can emerge. Next, we include an external potential and electron-electron interactions, which are treated within the Hartree approximation. Then, we write down a formal general solution to the problem, giving additional details for the case of a symmetric external potential. Concentrating on the case of a single crossing, we were able to explain recent experinents on crossed metallic and semiconducting nanotubes [J. W. Janssen, S. G. Lemay, L. P. Kouwenhoven, and C. Dekker, Phys. Rev. B 65, 115423 (2002)], which showed the presence of localized states in the region of crossing.Comment: 11 pages, 10 figure