DSpace Собрание:
http://hdl.handle.net/11701/6582
Fri, 23 Aug 2019 12:01:58 GMT2019-08-23T12:01:58ZSergey Vasiljevich Vallander. By the 100th anniversary of his birth
http://hdl.handle.net/11701/6957
Название: Sergey Vasiljevich Vallander. By the 100th anniversary of his birth
Краткий осмотр (реферат): Sergey Vasiljevich Vallander. By the 100th anniversary of his birthThu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69572017-06-01T00:00:00ZSurfaces of minimal energy and their singular points in the problem of stellar approaches toward the solar system
http://hdl.handle.net/11701/6956
Название: Surfaces of minimal energy and their singular points in the problem of stellar approaches toward the solar system
Авторы: Mammadli, Azad Hidayat oglu
Краткий осмотр (реферат): Planetary motion during stellar approaches toward the Solar System is examined in the framework of
the three-dimensional restricted three-body problem. The exact expression of the force function without
a series expansion is used. Regions of possible motion of a planet are determined. Surfaces of minimal
energy, which are generalizations of surfaces of zero velocity, are plotted. Singular (exceptional) points of
these surfaces are determined, and their type and Lyapunov stability are ascertained. The results thus
obtained are shown in the form of figures and tables. Refs 5. Figs 2. Table 1.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69562017-06-01T00:00:00ZLong-wave vibrations and waves in anisotropic beam
http://hdl.handle.net/11701/6955
Название: Long-wave vibrations and waves in anisotropic beam
Авторы: Tovstik, Petr E.; Tovstik, Tatiana P.; Naumova, Natalia V.
Краткий осмотр (реферат): Long-wave vibrations and waves in infinite non-homogeneous in thickness of anisotropic beam-belt are
investigated by using asymptotic methods. Dispersion equation of second order accuracy on the relative
beam thickness are obtained. Additional quality effect related to anisotropy are noticed. Refs 25. Tables 2.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69552017-06-01T00:00:00ZSpatially homogeneous relaxation of CO molecules with resonant V E transitions
http://hdl.handle.net/11701/6954
Название: Spatially homogeneous relaxation of CO molecules with resonant V E transitions
Авторы: Mishina, Alena I.; Kustova, Elena V.
Краткий осмотр (реферат): In this paper we study vibrational relaxation of CO molecules with excited electronic states. We consider
three electronic terms and account for V V exchanges of vibrational energy within each electronic term,
V T transitions of vibrational energy into translational and V E exchange of vibrational energy between
electronic terms. The initial vibrational state of the gas is strongly non-equilibrium. The effect of V E
exchange on the vibrational relaxation of CO molecules is evaluated for different kinds of initial vibrational
distributions, in particular, the Treanor and Gordiets ones generalized for gases with electronically excited
states. The set of equations of state-to-state vibrational kinetics coupled to the gas-dynamic equations
is solved numerically in the zero-order approximation of the Chapman-Enskog method for the case of
spatially homogeneous relaxation. The following results were obtained: neglecting V E exchanges leads to
an incorrect assessment of the numerical density for each electronic level, however, the error is small for
the ground electronic state. It is shown that V E exchanges qualitatively affect the time dependence of the
vibrational temperature. Refs 17. Figs 5.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69542017-06-01T00:00:00ZWorkspaces of a Steward’s platform in the 6D space of generalised coordinates
http://hdl.handle.net/11701/6953
Название: Workspaces of a Steward’s platform in the 6D space of generalised coordinates
Авторы: Leonov, Gennady A.; Tovstik, Petr E.; Tovstik, Tatiana M.
Краткий осмотр (реферат): Kinematics and dynamics of a classic Steward’s platform is studied. The platform is a rigid body supported
on 6 rods of variable length. The well known differential equations, describing the platform motion, are
presented. The main attention is paid to the analysis of workspaces in the 6D space of generalized coordinates.
The projections of these workspaces on the spaces of the smaller dimensions are found. The 1D
and 2D projections are built as in a linear so in a nonlinear approach. The 3D parallelepipeds of maximum
volume, lying in the workspace, are found. Refs 15. Figs 4. Tables 3.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69532017-06-01T00:00:00ZNonexistence of liouvillian solutions in the problem of motion of a rotationally symmetric ellipsoid on a perfectly rough plane
http://hdl.handle.net/11701/6952
Название: Nonexistence of liouvillian solutions in the problem of motion of a rotationally symmetric ellipsoid on a perfectly rough plane
Авторы: Kuleshov, Alexander S.; Itskovich, Mikhail O.
Краткий осмотр (реферат): We consider the classical problem of nonholonomic system dynamics the problem of motion of a
rotationally symmetric ellipsoid on a fixed perfectly rough horizontal plane. It is well known that the
solution of this problem is reduced to the integration of the second order linear differential equation with
respect to r the projection of the angular velocity of the ellipsoid onto its axis of symmetry. Using the
Kovacic algorithm we prove the nonexistence of liouvillian solutions for the corresponding second order
linear differential equation for almost all values of parameters of the problem. The paper is organized as
follows. After the introductory paragraph, in the second paragraph we briefly discuss the Kovacic algorithm
for solving the second order linear differential equation. In the third paragraph we apply this algorithm
to the problem of motion of a rotationally symmetric ellipsoid on a perfectly rough horizontal plane and
prove the nonexistence of liouvillian solutions in the considered problem. Refs 4.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69522017-06-01T00:00:00ZCorrelation between properties of eigenfrequencies and eigenmodes in a chain of rigid bodies with inertialess moment connections
http://hdl.handle.net/11701/6951
Название: Correlation between properties of eigenfrequencies and eigenmodes in a chain of rigid bodies with inertialess moment connections
Авторы: Indeitsev, Dmitry A.; Sergeev, Aleksander D.
Краткий осмотр (реферат): A regular chain of N rigid bodies is under consideration. Each body has one degree of freedom: rotation
along the axis, orthogonal to the chain axis. Bodies of the chain are connected by means of elastic
inertialles Bernoulli-Euler beams. We build the analytical solution of eigenvalue problem for the chain
if N is arbitrary. The properties of eigenfrequencies and eigenmodes of the chain are compared with
analogical properties of the canonical Newton chain. It is shown that the correlation between properties
of eigenfrequencies and eigenmodes in a rigid body chain with inertialess torque connections and the
same correlation in the canonical Newton chain is principally different. The eigenmodes, corresponding
to the lowest eigenfrequencies of the rigid body chain, have maximal number of nodes. The eigenmodes,
corresponding to the highest eigenfrequencies of this chain are most smooth. The nontypical correlation,
obtained as a result of the precise solution, goes in contradiction to the states, putted by physics into
the foundation of theoretical investigations devoted to various dynamical phenomena in crystal lattices.
Refs 8. Figs 7.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69512017-06-01T00:00:00ZEquilibrium composition and physical and chemical characteristics of high-temperature air mixtures with diverse densities
http://hdl.handle.net/11701/6950
Название: Equilibrium composition and physical and chemical characteristics of high-temperature air mixtures with diverse densities
Авторы: Bogdanova, Natalia V.; Rydalevskaya, Maria A.
Краткий осмотр (реферат): The equilibrium composition and physical and chemical characteristics changes of the air are investigated
when his temperature increase. The distribution functions which correspond to entropy maximum are
used for a description of equilibrium states of the air mixtures. It allows us to avoid the solution of a mass
action law equations. Therefore, the determination of the equilibrium mixture composition is simplified.
The influence of initial air density on the dependencies of the mixture components concentrations, the
mole mass and the pressure on the temperature is analyzed. Refs 12. Figs 5.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69502017-06-01T00:00:00ZStability loss of an infinite plate with a circular inclusion under uniaxial tension
http://hdl.handle.net/11701/6949
Название: Stability loss of an infinite plate with a circular inclusion under uniaxial tension
Авторы: Bauer, Svetlana M.; Kashtanova, Stanislava V.; Morozov, Nikita F.; Semenov, Boris N.
Краткий осмотр (реферат): The problem of the stability loss of an infinite plate with a circular insert with another material exposed to
uniaxial tension is considered. The influence of elastic modulus of the insert to the value of the critical load
is defined. For finding the minimum eigenvalue corresponds to the first critical load is applied variational
principle.
The calculations are performed in the programm “Maple” and compared with the results obtained
by the method of finite elements in ANSYS.
The calculations show that the loss of stability in the case when the inclusion softer than the plate,
and when the inclusion more firm than plate occurs in different forms, and at the approach of the Young’s
modulus of the inclusion to the Young’s modulus of the plate critical load essentially increases. In the case
of the coincidence of elastic modulus of the plate and inclusion stability loss is impossible. Refs 10. Figs 5.
Table 1.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69492017-06-01T00:00:00ZAging and fracture of compressible elasticviscous media
http://hdl.handle.net/11701/6948
Название: Aging and fracture of compressible elasticviscous media
Авторы: Arutyunyan, Alexander R.; Arutyunyan, Robert A.
Краткий осмотр (реферат): During the prolonged action of mechanical stresses and moderate temperatures the interrelated processes
of deformation and damage in polymer materials are occured. These processes lead to destructive effects
and are accompanied by chemical reactions, which increase the structure changes and properties of the
considered materials. Accordingly, it is possible to distinguish two types of fracture of polymeric materials
during long-term mechanical and thermal effects. The first type (mechanical) is implemented in the
condition of active loading, and in experiments on creep at moderate temperatures. The second type of
fracture (chemical) is associated with the accumulation of structural damage in the long process of aging in
the absence of external stress (static fatigue). The modified version of Maxwell’s equation and the equation
for the damage parameter are formulated. The analytical solutions for the creep and stress relaxation are
derived. Unlike Maxwell formula, the stress relaxation ratio has not zero asymptote. To describe the creep
deformation and fracture of a compressible elastic-viscous medium the Boltzmann Volterra equation is
used. An analytical solution for the continuity parameter and the long-term strength criterion is received.
The theoretical curves for the continuity parameter and the long-term strength criterion are plotted.
Quantitative and for creep curves qualitative agreement with the corresponding experimental curves are
observed. Refs 12. Figs 6.Thu, 01 Jun 2017 00:00:00 GMThttp://hdl.handle.net/11701/69482017-06-01T00:00:00Z