Vol 20, No 3 (2014)
- Year: 2014
- Articles: 24
- URL: https://journals.ssau.ru/est/issue/view/220
Articles
TASK ON LONGITUDINAL VIBRATIONS OF A ROD WITH DYNAMIC BOUNDARY CONDITIONS
Abstract
In this paper, one-dimensional longitudinal vibration of a solid rod fixed at the ends by means of local masses and springs is studied. As a mathematical model we use Rayleigh rod. The existence and uniqueness of a generalized solution are proved.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):9-19
9-19
REDUCTION OF MATHEMATICAL MODEL OF ROBOT WITH ELASTIC JOINTS
Abstract
A model of n - joint manipulator with elastic joints with small dissipation is studied. Class of singularly perturbed differential systems that describe the dynamics of robot is singled out. For a given class of systems the existence and uniqueness of integral manifoldness of slow movement is established, its features are studied. It is proved that integral manifold may be constructed with any degree of accuracy as asymptotic decomposition inpowers of small parameter. System that is used to describe movement in manifolds may be used as a reduced model of initial system.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):20-33
20-33
FIELD OF INVARIANTS OF BORELEAN GROUP OF ADJOINT REPRESENTATION OF GL(n,K)
Abstract
The paper is devoted to invariant theory problems, in particular to the problem of finding generators of invariant fields in an explicit form. The set of generators is given for invariant field of unitriangular group concerning the ad-joint representation of GL(n, K) group. Moreover, the set of generators of Borel group for the field of invariants is constructed and their algebraic independence is proved.
Lie group; |
adjoint representation; |
field of invariant; |
generators of the field of invariants; |
Borel group; |
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):34-40
34-40
EIGENVALUE PROBLEM FOR THE LAPLACE OPERATOR WITH DISPLACEMENT IN DERIVATIVES
Abstract
The statement of the problem on the determination of eigen-and adjointfunctions for Laplace operator in s-dimensional unit ball with displacement in derivatives is given. For s =2 the conditions are obtained for the existence of adjoint functions of the not higher than three order and their computation is made. The case of arbitrary s is the subject of future work.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):41-45
41-45
PROBLEM WITH NONLOCAL INTEGRAL CONDITION FOR PSEUDOHYPERBOLIC EQUATION OF THE FOURTH-ORDER
Abstract
In this article, we study a problem for a multimensional pseudohyperbolic equation of the fourth-order with an integral condition. Existence and uniqueness of a generalized solution is proved.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):46-55
46-55
56-66
THE EXACTNESS OF THE GERSTEN COMPLEX FOR ADZUMAYA ALGEBRAS IN EQUICHARACTERISTIC CASE
Abstract
One of the well-known problems of algebraic K-theory is the Gersten conjecture. In this work we prove a variant of Gersten conjecture for Adzumaya algebras in equicharacteristic case. Geometrical case of this proposition was proved in the article by I. Panin and A. Suslin.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):67-75
67-75
BASIS OF MULTILINEAR PART OF LEIBNIZ ALGEBRAS MANIFOLDS \overbrace{V_1}
Abstract
In the case of trivial characteristic of base field, Leibniz algebras manifolds defined by the identity x_1(x_2x_3)(x_4x_5)\equiv 0. has almost polynomial growth. In the work we continue research of this manifold, in particular, we construct bases of multilinear parts.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):76-82
76-82
INVERSE PROBLEM WITH INTEGRAL OVERDETERMINATION CONDITION FOR A HYPERBOLIC EQUATION
Abstract
In the paper, we study an inverse problem for a hyperbolic equation with integral overdetermination condition. The existence of a generalized solution is proved.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):83-92
83-92
STABILIZATION OF GENERALIZED SOLUTION OF THE THIRD BOUNDARY PROBLEM FOR A PARABOLIC EQUATION
Abstract
With increasing time generalized solution of the problem with time-periodic parameters tends to time periodic function if some parameters satisfy the positivity or non-negativity. If parameters are not periodic in time, then the solution converges to the solution of the same problem with zero initial function.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):93-96
93-96
DESCRIPTION OF DETERIORATION PROCESSES: DAMAGE PARAMETER OF Y.N. RABOTNOV: HISTORICAL REMARKS, FUNDAMENTAL RESULTS AND CONTEMPORARY STATE
Abstract
In the paper the detailed review of the present-day results related to problems of continuum damage mechanics is given. The survey shows the development of ideas of Y.N. Rabotnov who together with L.M. Kachanov introduced damage and continuity variables which characterize the damage state. In the paper the recent studies in the elasticity, plasticity and creep theories accounting for damage accumulation processes are discussed.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):97-114
97-114
EMPIRICAL ANALYSIS OF APPROXIMATE ALGORITHMS FOR INTEGER PROGRAMMING, BASED UPON THE IDEA OF GREEDY CHOICE
Abstract
The article contains the results of empirical studies of heuristic algorithms for integer programming based upon the idea of greedy choice. On the base of numerous computer experiments estimate of average level of inaccuracy of approximate solution are presented.
The article contains the results of empirical studies of heuristic algorithms for integer programming based upon the idea of greedy choice. On the base of numerous computer experiments estimate of average level of inaccuracy of approximate solution are presented. |
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):115-120
115-120
ADVANCED SEMICONDUCTOR MATERIALS FOR THE DEVELOPMENT OF SUPER-HIGH FREQUENCIES AND NANOELECTRONICS
Abstract
The results of application of semi-conductor converters on the basis of silicon carbide as a sensitive super-high frequency signals recorder. It was also noted that this material is prospective in the development of such areas as medicine, aerospace equipment, high-speed communication lines. The necessity of silicon carbide is increasing for its application in nanoelectronics.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):121-127
121-127
INFLUENCE OF THE SADDLE-SPLAY CONSTANT ON THE DIRECTOR FIELD DISTRIBUTION IN STRONG MAGNETIC FIELDS
Abstract
The role of anchoring effects in thin nematic films confined between two parallel plates was theoretically examined. The bulk and surface free energy densities weree xpanded up to O(e2) and the perturbated contributions were calculated. It is shown that the minimum of the free energy corresponds to the solution of the Euler-Lagrange equations and satisfies the Ericksen inequalities. The identified bifurcation points can estimate the influence of the saddle-splay constant k24 towards periodic perturbations of a director in the presence of strong magnetic field.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):128-135
128-135
DETERMINATION OF MOLECULAR WEIGHT AND BOILING TEMPERATURE OF UNKNOWN COMPONENTS OF A MIXTURE BY MEANS OF CHROMATE-DISTRIBUTIVE METHOD
Abstract
New technique, allowing to increase the accuracy of determination of molecularweight andboiling temperature of unknown components of analyzing mixture, in comparison with our work described in the journal ”Sorption and Chromatographic Processes” 2011, № 4. and based on information on sizes of indexes of retention of Van den Dool and Krats and indexes of the logarithm of constant of distribution in the system ”hexane - acetonitrile”is suggested.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):136-147
136-147
THEORETICAL STUDY OF NUCLEOSIDE5´-PHOSPHORAZOLIDE-2´,3´-CYCLO(THIO)CARBONATE FORMATION POSSIBILITY IN REACTION OF NUCLEOTIDES AND N,N´-ACYLBISAZOLES BY QUANTUM-CHEMICAL METHODS
Abstract
Nucleoside-5´-phosphates and N,N´-(thio)carbonylbisazoles interaction was studied for the evaluation of nucleoside-5´-phosphorazolide-2´,3´cyclo(thio)carbonate formation possibility by the semi-empirical method PM6 of SCIGRESS Modeling 3.0.0 software. Azole moiety involves imidazole fragment. It was shown that formation of nucleoside-5´-phosphorazolide2´,3´-cyclo(thio)carbonates is energetically less efficient than formation of nucleotide-5´-phosphorazolides.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):148-153
148-153
STUDY OF CHEMISTRY OF FORMATION OF BARIUM AZIDE
Abstract
This article proposes a chemism of the barium azide formation through monoazidometilat barium. The results obtained allowed to eliminate possible stops of the process due to formation of gelatinous mass by varying duration of the process.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):154-157
154-157
INFLUENCE OF TOBACCO SMOKING ON THE FUNCTIONAL STATE OF A BODY OF YOUNG MALE RESIDENTS OF MAGADAN REGION
Abstract
In the investigation carried out with the participation of 87 smokers and 60 nonsmokers of young male residents of Russia’s northeast, the changes in morphofunctional parameters in dependence on their relevance to smoking were investigated. It was found out that no significant difference between the groups was observed in basic somatometric values as well as in the body cardiorespiratory or gasotransporting system. At the same time the revealed changes testify to the tendency towards higher tension in the work of body functional systems shown by the people who abuse smoking.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):158-169
158-169
EFFECT OF MEMBRANE DEPOLARISATION OF SUPRACHIASMATIC NUCLEUS NEURONS ON SPIKE ACTIVITY IN VITRO
Abstract
The properties of spike activity of neurons of the suprachiasmatic nucleus during their membrane depolarisation in vitro are investigated on rat hypothalamic slices. Depolarisation of membrane caused an increase in activity of cells and a decrease in entropy log interspike interval distribution were used as a measure of spikes irregularity generation. Possible mechanisms of the effects are discussed.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):170-177
170-177
GENETIC POLYMORPHISM OF GENES ASSOCIATED WITH VIRULENCE IN MYCOBACTERIUM TUBERCULOSIS STRAINS FROM SAMARA REGION
Abstract
The prevalence of polymorphisms in Mycobacterium tuberculosis genes associated with virulence as well as its associations with genetic groups, clusters of strains and drug susceptibility was investigated in the article. The associations between polymorphisms in plcA gene and some LAM family clusters, dosT and pks15/1 genes and Beijing family and lipR gene and the majority of Ghana, Cameroon, Uganda and S clusters were found. Detected interrelation between studiedpolymorphisms and drug susceptibility is of mediated character.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):178-186
178-186
BREATHING PARAMETERS IN STUDENTS WITH DIFFERENT TYPES OF BIORHYTHMS
Abstract
With the use of technique of spirography it was shown that background values of breathing pattern parameters in students depend on their biorhythmological features and time of day. Most prominent changes in breathing during the day were found in students with ”intermediate” type of circadian activity, and less prominent - in students with late” type of activity. Significant differences in values of respiratory frequency and in duration of respiratory phases between students with ”early” and ”intermediate” circadian activity were found, and also the differences in frequency and volume parameters of breathingbetween persons with ”intermediate” and ”late” activity in the morning and in the evening were registered. The differences in dynamics of respiratory parameters between persons with ”early” and ”late” types of activity were not significant.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):187-196
187-196
CORRELATION OF METABOLIC ACTIVITY OF MICROORGANISMS AND MICROARTHROPODS IN THE PROCESS OF DESTRUCTION OF PLANT RESIDUES
Abstract
On the basis of instrumental studies the contribution of microorganisms and small arthropods to the metabolism of soil biota in the decomposition of plant residues was estimated numerically. The dependence of metabolism of biological degradation agents on their biomass was shown.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):197-201
197-201
SPATIAL PICTURE OF DISTRIBUTION OF ELECTROENCEPHALOGRAM RHYTHMS IN THE RIGHT-HANDED STUDENTS DURING AN EXAM
Abstract
Registration of electroencephalogram (EEG) in the right-handed students during an exam revealed weakening of alpha rhythm in all areas of right and left cerebral hemispheres as well as increased beta rhythm in parietal and end-lobes of the right hemisphere. Simultaneously regular delta waves in the frontal leads ofboth hemispheres and theta waves in right frontal, occipitalis and temporal leads were marked. Offset of EEG slow wave activity in the right hemisphere in partial right-handers was marked in more noticeable way than in that of the true right-handers. The obtained data suggest that the distribution of EEG rhythms in condition of mental and emotional stress in right-handers depends on the type and severity of functional hemispheric asymmetry.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):202-212
202-212
AREAS OF THE SAMARA REGION WITH A HIGH DEGREE OF PRESERVATION OF NATURAL LANDSCAPES, PROSPECTIVE FOR ORGANIZING OF SPECIALLY PROTECTED NATURAL AREAS ON THE BASIS OF THEIR FLORISTIC DESCRIPTIONS, AND REVEALING OF RARE INSECT SPECIES
Abstract
There have been allocated 6 territories in 4 districts of Samara Region on the basis of their floristic descriptions, and revealing of rare insect species, which are prospective for organizing of specially protected natural areas within proposed boundaries.
Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series. 2014;20(3):213-230
213-230