Vol 18, No 9 (2012)
- Year: 2012
- Articles: 22
- URL: https://journals.ssau.ru/est/issue/view/231
Articles
ON ONE PROBLEM IN INFINITY STRIP FOR BIAXISYMMETRIC HELMHOLZ EQUATION
Abstract
Boundary value problem with special conditions on line y = 0 in infinity strip 0<x<a for generalized biaxisymmetric Helmholz equation is set. Conditions of this problem set difference of some one-sided limits of known functions. Unknown function is zero in the right boundary and in infinity. Unknown functions with weight for one parameter ц value and without weight for other. Existence of solution is proved for some conditions. Uniqueness of solutions is proved for other some conditions.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):5-13
5-13
COMPARATIVE CHARACTERISTICS OF VARIOUS SYSTEMS OF BASIS FUNCTIONS OF THE FULL FIELD, WITH REGARD TO THE SOLUTION OF INTEGRAL FREDHOLM EQUATIONS OF THE SECOND KIND
Abstract
The article examines some aspects of numerical solution of some problems of antenna electrodynamics, reducible to the integral equations of the second kind with the use of various bases of decomposition of the sought function.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):14-21
14-21
ON CERTAIN INITIAL-BOUNDARY VALUE PROBLEMS WITH NONLINEAL BOUNDARY CONDITIONS FOR HYPERBOLIC EQUATION
Abstract
In this paper, we study the solvability of a problem for a nonlinear hyperbolic equation with a nonlinear boundary conditions. The unique solvability is proved.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):22-30
22-30
NERON MODEL OF TWO-DIMENSIONAL ANISOTROPIC ALGEBRAIC TORI OVER LOCAL FIELDS
Abstract
The construction of integral models is necessary for the research on arithmetical properties of algebraic tori. Neron model, having some unique properties, is of special interest among different possible integral models of algebraic tori over local fields. Its definition is not constructive, though. That's why its construction is an important problem. In this paper the problem of explicit construction of Neron model is solved for all two-dimensional anisotropic algebraic tori over local fields.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):31-40
31-40
ON NORMS AND CERTAIN CHARACTERISTICS OF TRIGONOMETRIC APPROXIMATION BY BASKAKOV OPERATORS
Abstract
The article covers actual question in the theory of approximations. It researches approximative opportunities of concrete approximating structures. In the article one of the actively studied in recent times types of approximating operators — Baskakov's trigonometric operators. Some characteristics of these operators are being investigated: norms and approximation constants, assessment and improved. In particular, the assessment of their difference is obtained.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):41-51
41-51
ON A PROBLEM WITH GENERALIZED OPERATORS OF FRACTIONAL DIFFERENTIATION FOR A DEGENERATED INSIDE A DOMAIN HYPERBOLIC EQUATION
Abstract
In this paper, we consider a problem with Saigo operators of fractional differentiation in a boundary condition on a characteristic part of a boundary. The unique solvability of this problem is proved.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):52-60
52-60
UNIFORM EXHAUSTIVITY OF A FAMILY OF REGULAR SET FUNCTIONS ON TOPOLOGICAL SPACES
Abstract
Conditions for the uniform exhaustivity of a family of regular set functions defined on an algebra £ of subsets of a cr-topological space and taking values in arbitrary topological space are found.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):61-69
61-69
ON DEVELOPMENT OF MULTISCALE FRACTURE MODELS
Abstract
An approximate solution of nonlinear eigenvalue problem arising from the Mode I crack problem in a nonlinear power-law medium is obtained. The perturbation technique is used. The method allows to find the analytical formula expressing the eigenvalue as the function of parameters of constitutive law and eigenvalue corresponding to the linear undisturbed problem.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):70-83
70-83
STABILITY OF ROTATING CIRCULAR CYLINDRICAL SHELL SUBJECT TO AN AXIAL AND ROTATIONAL FLUID FLOW
Abstract
This paper is concerned with the stability analysis of rotating cylindrical shells conveying a co-rotating fluid. The problem is solved by the finite element method for shells subjected to different boundary conditions. It has been found that the loss of stability for a rotating shell under the action of the fluid having both axial and circumferential velocity components depends on the type of boundary conditions imposed on the shell ends. The results of numerical calculations have shown that for different variants of boundary conditions a simultaneous rotation of shell and the fluid causes an increase or decrease in the critical velocity of axial fluid flow.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):84-97
84-97
TO THE THEORY OF PRESSURE DECREASE OF STEAM ADJOINING TO A LIQUID IN THE CLOSED VOLUME
Abstract
In work the problem of pressure decrease of steam in the closed volume owing to condensation on border of contact to a cold liquid is considered. The nonlinear integrodifferential equations which numerical decision is executed by a method of final differences are received. Influence of an initial condition and the expense of a liquid, the geometrical size of the closed volume on rate of pressure decrease is analysed.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):98-105
98-105
THEORETICAL METHODS OF NANOSTRUCTURES INVESTIGATION
Abstract
In this work, a review is presented concerning the most modern theoretical methods aimed at investigation of various nanostructures properties. The basic concepts of ab initio methods, density functional, semi-empirical and empirical methods are considered. The applicability boundaries of calculation schemes utilized in the aforementioned methods are denoted.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):106-117
106-117
OPTIMAL CONTROL OF THREEFOLD INTEGRATOR ACCORDING TO MINIMUM CONSUMPTION
Abstract
The solution of optimal control problem of the threefold integrator with any boundary conditions by method of moments is considered. It is shown that in case of minimization of total impulse of control influence or control consumption, the solution of L
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):118-129
118-129
MODELING OF POTENTIAL FIELDS BY METHOD OF BOUNDARY TRANSFORMATION OPERATORS
Abstract
In the article the method of boundary transformation operators is offered. It supplements classical methods and allows to find the solution of regional tasks in the closed look that opens new opportunities in the simulation of potential fields. Application of the developed method allowed to solve a number of problems of potential theory and apply to the research a package of applied MatLab programs.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):130-135
130-135
NEW CASE OF INTEGRABILITY IN DYNAMICS OF MULTI-DIMENSIONAL BODY
Abstract
In this chapter the new results are systematized on study of the equations of motion of dynamically symmetrical four-dimensional (4D—) rigid body which residing in a certain nonconservative field of forces in case of special dynamical symmetry. Its type is unoriginal from dynamics of the real smaller-dimensional rigid bodies of interacting with a resisting medium on the laws of a jet flow, under which the nonconservative tracing force acts onto the body and forces both the value of velocity of a certain typical point of the rigid body and the certain phase variable to remain as constant in all time, that means the presence in system nonintegrable servo-constraints.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):136-150
136-150
ENTANGLEMENT OF TWO DIPOLE-COUPLED ATOMS INTERACTING WITH TWO-MODE THERMAL FIELD IN THE CAVITY WITH HIGH TEMPERATURE
Abstract
The entanglement of two dipole-coupled atoms with nondegenerate two-photon transitions interacting with two-mode field in lossless cavity has been investigated. The possibility of considerable growth of atomic entanglement is shown in the case of great mean values of thermal photons.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):151-158
151-158
MONTE-CARLO SIMULATIONS OF PHASE TRANSITIONS IN THE TWO-DIMENSIONAL ISING MODEL WITH LONG-RANGE CORRELATIONS
Abstract
In this article phase transitions in the modified two-dimensional Ising model with long-range correlations investigated. This model was studied with Monte-Carlo method and Metropolis algorithm. Critical temperature increase is shown in such model.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):159-163
159-163
DISTRIBUTION OF POINT DEFECTS IN THE SI-FAZE INCLUDING SIC-FAZE, FORMED BY ENDOTAXE METHOD OF SEMICONDUCTOR HETEROSTRUCTURES
Abstract
Heteroepitaxy layers of silicon carbide on silicon substrates is one of the best candidates for high-power, high-temperature and high-frequency applications in electronics. Solid-phase process of endotaxe of silicon carbide is accompanied by evolution of Si-phase into Sic-one in hydrogen hydrocarbon atmosphere at temperature range 1360-1380 °C and normal pressure. The distribution of thermal intrinsic point defects of different nature in silicon substrates in dependence of the type of its conductivity and in conditions of isovalent doping of carbon is investigated in this paper.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):164-179
164-179
CONCERNING THE FEATURES OF INTERSPECIES DIVERSITY IN THE POPULATION GROUPS OF MILK THISTLE
Abstract
The data on some phenotypic features of 40 population groups of Silybum marianum Gaertn, created on the base of seeds with different geographic origin during the field investigations in 1989-2006 in Samara region are given in the article. The problem of possible connection between morphological and quantitative, especially productivity-connected, parameters is discussed.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):180-190
180-190
FLORISTIC STRUCTURE OF WESTERN PARTS OF THE SOKOLI HILLS
Abstract
Features of floristic structure of the Sokoli Hills are considered. In the western parts of the Sokoli Hills 208 species of vascular plants, including 155 genera, 54 families, 6 classes and 4 sections were exposed.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):191-199
191-199
EFFECTS OF POLLUTANTS ON ENZYME ACTIVITIES IN WATER SUBMERGED PLANT CERATOPHYLLUM DEMERSUM
Abstract
In this paper the effects of heavy metal ions (Pb2+) and cationic surfactants combination on enzyme activities in water submerged plant Ceratophyllum demersum are considered.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):200-210
200-210
MODIFICATION OF THE METHOD FOR DETERMINATION OF OXYPROLINE IN BLOOD SERUM
Abstract
A comparative study of serum fractions associated oxyproline underwent various periods of hydrolysis. Its duration depends on the completeness of splitting associated and consequently the accuracy of its content in the blood serum. The studies were conducted on children diagnosed with juvenile idiopathic arthritis. Depending on the performance OP also noted the state of bone tissue in children when they are sick.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):211-216
211-216
THE INFLUENCE OF ALLOGENIC HYDROXYAPATITE ON KATALASE ACTIVITY, DIEN CONJUGATS AND MALONE DIALDEHYDE IN RATS
Abstract
The antioxidant system activity in liver and muscle of rat after bilateral ovaryectomy and allogenic hydroxyapatite injections was investigated. The decrease of antioxidant system activity in rats with removed ovaries was found. Injections of allogenic hydroxyapatite leads to normalization of antioxidant system activity.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2012;18(9):217-226
217-226