Water vole (Arvicola amphibius) as an object of long-term biomonitoring in a floodplain area (Western Siberia, Russia)

The paper is devoted to the dynamics of the water vole population in the conditions of total deforestation of valley forests and their subsequent restoration. We analyzed the relative population of small mammals in the typical biotopes in the Tom River basin (Western Siberia) on the border of the forest-steppe and taiga zones. From 1978 to 2019, 1,139 water voles Arvicola amphibius (Linnaeus, 1758) (synonym of A. terrestris) were caught with 50-meter trapping grooves; for 788 individuals we assessed the condition of non-metric features (phenes) of the skull. It was found that changes in the population level are non-cyclical, while against the background of a generally low occurrence of the species in the region, the population level increased tenfold in some years. It was shown that such episodic population surges can significantly impact the structure of the community of small mammals. In the valley of the Tom River, the water vole prefers inhabit wet meadows and ecotone areas between the meadow and the dark coniferous taiga forest. During the years of population surges, the water vole intensely occupies new nesting sites due to the dispersal activity of young animals but at the same time retains the original biotopic preferences. Dispersal of the species takes place in waterlogged wetlands. Most of the animals caught during the peak of their numbers were young animals of late broods born from overwintered individuals. The conducted phenetic analysis revealed the heterogeneity of young animals during the population surge, which allowed us to assume the participation of several populations in the formation of the peak. In the final surge year, the surge was characterized by an extremely low percentage of participation in the breeding of young females and the appearance of a large number of weakened animals, which led to crisis in the species population and the disappearance of the water vole from the captures. The research shows that one cannot predict the success of this process at the current stage; therefore, after flooding, it is necessary to continue monitoring

Dimension on Discrete Spaces

In this paper we develop some combinatorial models for continuous spaces. In this spirit we study the approximations of continuous spaces by graphs, molecular spaces and coordinate matrices. We define the dimension on a discrete space by means of axioms, and the axioms are based on an obvious geometrical background. This work presents some discrete models of n-dimensional Euclidean spaces, n-dimensional spheres, a torus and a projective plane. It explains how to construct new discrete spaces and describes in this connection several three-dimensional closed surfaces with some topological singularities It also analyzes the topology of (3+1)-spacetime. We are also discussing the question by R. Sorkin [19] about how to derive the system of simplicial complexes from a system of open covering of a topological space S.Comment: 16 pages, 8 figures, Latex. Figures are not included, available from the author upon request. Preprint SU-GP-93/1-1. To appear in "International Journal of Theoretical Physics

Kinematic Control of the Inertiality of the System of Tycho-2 and UCAC2 Stellar Proper Motions

Based on the Ogorodnikov-Milne model, we analyze the proper motions of Tycho-2 and UCAC2 stars. We have established that the model component that describes the rotation of all stars under consideration around the Galactic y axis differs significantly from zero at various magnitudes. We interpret this rotation found using the most distant stars as a residual rotation of the ICRS/Tycho-2 system relative to the inertial reference frame. For the most distant ($d\approx900$ pc) Tycho-2 and UCAC2 stars, the mean rotation around the Galactic y axis has been found to be $M_{13}=-0.37\pm0.04$ mas yr$^{-1}$. The proper motions of UCAC2 stars with magnitudes in the range $12-15^m$ are shown to be distorted appreciably by the magnitude equation in $\mu_\alpha\cos\delta$, which has the strongest effect for northern-sky stars with a coefficient of $-0.60\pm0.05$ mas yr$^{-1}$ mag$^{-1}$. We have detected no significant effect of the magnitude equation in the proper motions of UCAC2 stars brighter than $\approx11^m$.Comment: 15 pages, 6 figure

The influence of Galactic aberration on precession parameters determined from VLBI observations

The influence of proper motions of sources due to Galactic aberration on precession models based on VLBI data is determined. Comparisons of the linear trends in the coordinates of the celestial pole obtained with and without taking into account Galactic aberration indicate that this effect can reach 20 $\mu$as per century, which is important for modern precession models. It is also shown that correcting for Galactic aberration influences the derived parameters of low-frequency nutation terms. It is therefore necessary to correct for Galactic aberration in the reduction of modern astrometric observations

МЕХАНИЗМЫ ОБРАЗОВАНИЯ СЛОИСТЫХ МНОГОФУНКЦИОНАЛЬНЫХ ПОКРЫТИЙ НА ОСНОВЕ КАРБИДА КРЕМНИЯ

The paper investigates regularities pertaining to structure formation in a thin-film coating applied on diamond crystals by magnetron dispersion of a combined cathode (Si + C). It has been  established that an amorphous layer of  Si and C atom mixture is formed in the condensation process of a thin-film coating (up to 20 µm) and its glow-discharge plasma processing  is accompanied by action of plasma particles along with formation of surface  waves that contributes to transfer of  active carbon atoms and formation of stronger Si – C connection. Structure formation in coatings (Si + C) with thickness over 100 µm proceeds according to diffusion mechanism at low temperatures (650–850ºС) with  formation of α-SiC with  an  amorphous layer. Solid-phase reactive sintering of simple elements (silicon and carbon) in nano-coatings obtained with the help of diamond powders allows to make composites of such powders with the given complex of properties due to control of  structure of particle-connection zone on atom-cluster levels.Изучены закономерности структурообразования в тонкопленочном покрытии, наносимом на кристаллы алмаза магнетронным распылением комбинированного катода (Si + C). Установлено, что в процессе конденсации тонкопленочного покрытия (до 20 нм) формируется аморфный слой из смеси атомов Si и C, обработка которого плазмой тлеющего разряда сопровождается воздействием частиц плазмы с формированием поверхностных волн, что способствует перемещению активных атомов углерода  и  образованию  более  сильной  связи  Si–C.  В покрытиях (Si + C) толщиной свыше 100 нм структурообразование протекает по диффузионному механизму при низких температурах (650–850 ºС) с образованием α-SiC с аморфным слоем. Твердофазное реакционное спекание простых элементов (кремния и углерода) в нанопокрытиях, полученных на алмазных порошках, позволяет изготовить композиты из таких порошков с заданным комплексом свойств за счет управления строением зоны соединения частиц на атомном и кластерном уровнях

Економіка зарубіжних країн

-Навчальний посібник доповнено новими фактичними й статистичними даними, а також розширено за змістом. Розглядаються найважливіші аспекти економіки зарубіжних країн в їх цілісній взаємодії, що формує світову економіку. Основна увага приділяється характеристиці типологічної та регіонально-інтеграційної структури країн світу. Розглядаються також стратегії економічного розвитку країн світу та макрорегіональних інтеграційних об’єднань. Для студентів економічних вузів та факультетів, а також для фахівців з міжнародної економіки.As the formative course of the study program it focuses on the particular economic problems of foreign countries not only the recent priorities but also the ideological background of current thinking. Students will become familiar with the position of some single economies and international organizations in world economy. The course consists of four parts. The first part covers problems of global economic classifications of countries. It also discusses the effects of economic integration and globalization on the global economy. The second part entitled covers the positions of the developed countries, developing countries and the least developed countries in a world economy . The third deals with economic growth strategies of some countries and regional integration strategies. The fourth part covers political and economic features of Ukraine, its position in the world economy. Moreover attention is paid to the integration process of Ukraine into the EU.

An Exactly Conservative Integrator for the n-Body Problem

The two-dimensional n-body problem of classical mechanics is a non-integrable Hamiltonian system for n > 2. Traditional numerical integration algorithms, which are polynomials in the time step, typically lead to systematic drifts in the computed value of the total energy and angular momentum. Even symplectic integration schemes exactly conserve only an approximate Hamiltonian. We present an algorithm that conserves the true Hamiltonian and the total angular momentum to machine precision. It is derived by applying conventional discretizations in a new space obtained by transformation of the dependent variables. We develop the method first for the restricted circular three-body problem, then for the general two-dimensional three-body problem, and finally for the planar n-body problem. Jacobi coordinates are used to reduce the two-dimensional n-body problem to an (n-1)-body problem that incorporates the constant linear momentum and center of mass constraints. For a four-body choreography, we find that a larger time step can be used with our conservative algorithm than with symplectic and conventional integrators.Comment: 17 pages, 3 figures; to appear in J. Phys. A.: Math. Ge

Міжнародні фінанси

У книзі йдеться про сутність міжнародних фінансів, закономірностях розвитку світової валютно-фінансової системи. Особливий наголос, у третьому виданні посібника, робиться на висвітленні питань щодо функціонування міжнародних фінансових ринків в умовах глобалізації, оподаткування в системі міжнародних відносин, особливостей міжнародного фінансового менеджменту. Призначена для викладачів і студентів економічних вузів, фахівців-практиків у галузі міжнародних фінансових відносин. In the textbook the international finances essence, the regularity of the world monetary and financial system development are distinguished. In the third edition the special focus is on the functioning of international financial markets in the context of globalization, taxation in the international relationship system and international financial management peculiar properties. For the lectures and students of economic universities, practice specialists of the international finance relationships

Международные экономические отношения : теория и политика

В книге международные экономические отношения рассматриваются в системе современной экономической теории. Особое внимание уделяется микроэкономическому и макроэкономическому механизмам их осуществления в условиях мировой интеграции и глобализации. Для преподавателей, студентов экономических вузов и факультетов, а также для специалистов-практиков в области международных экономических отношений. The textbook discusses the international economic relations in the modern economic theory. Particular attention is paid to microeconomic and macroeconomic mechanisms of their implementation in terms of global integration and globalization. For teachers, students of economic universities and faculties, as well as for practitioners in the field of international economic relations

Экспериментальное определение и численный расчет критерия вязкости разрушения

The paper shows that it is necessary to accept energy J-integral criterion as a criterion of fracture viscosity under conditions when the zone of plasticity is rather large at crack top. Numerical modeling of fracture process has shown good convergence with experimental investigations of J-integral parameter. Values of J-integral for 38ХНЗМФА steel, ЭП-131 cobalt alloy, MT molybdenum alloy have been experimentally determined. It is revealed that high-velocity deformation at explosive steel processing forms structure with high parameters of fracture viscosity and significant increase in material yield strength.Показано, что критерием вязкости разрушения в условиях, когда зона пластичности при вершине трещины значительная, следует принимать энергетический критерий J-интеграл. Численное моделирование процесса разрушения показало хорошую сходимость с экспериментальными исследованиями параметра J-интеграл. Экспериментально установлены значения J-интеграла для стали 38ХНЗМФА, кобальтового сплава ЭП-131, молибденового сплава МТ. Установлено, что высокоскоростная деформация при взрывной обработке стали формирует структуру с высокими показателями вязкости разрушения и значительным повышением предела текучести материала