Mathematical analysis.The
boundedness theorems in the spaces of continuous and summable functions
were proved for potential type operators and singular integrals
depending on the generalized shift generated by Bessel differential
operators and embedding theorems were established in Sobolev spaces
and Sobolev weight spaces generated by Bessel operator.
Necessary basicity condition of power system of the functions of
the form in the spaces was first found. Some analogy of the “
- Kadets” theorem in spaces at was found for perturbed system
of exponents.
A problem on finding analogies of the “ - Kadets” theorem
on the basicity of a system of exponents for sines, cosines systems
posed by Sedletskii in 1988 was completely solved.
N.K.Bari’s classical theorem on Riesz basicity of close systems
in Hilbert spaces that is transferred to Banach case, is revised.
In 1977 Yu. J. Kazmin pointed to impossibility of classical Stone-
Weierstrass approximation theorem to some systems, where linear
shell is not algebra. Generalization of the mentioned theorem was
found for the complex case that is applied to Yu.J.Kazmin case.
Sufficient conditions and compactness and nucleus property creation
of weight composition operators, and also for weight composition
type integral operators, induced by holomorphic vector poles in
uniform close subspaces of continuous functions on compacts are
also given.
Differential equations.The direct and inverse
scattering problems for a system of hyperbolic and ordinary differential
equations were studied. A unique renewal of coefficients with respect
to scattering operator for the considered system was proved. In
some cases the scattering data were introduced.
A unique solvability of mixed problems and quality properties of
their solutions in unbounded multivariate cylindric domains was
researched for Sobolev type equations.
Algebra. The existence of invariant subspaces
of semi – groups and Lie algebra of quasinilpotent compact
operators was proved. The joint spectral radius formulae were obtained,
new topological radicals were defined.
Approximation theory. A formula for calculation
of the best approximation was found and extremal function was constructed.
The jump problem was solved in a class of generalized analytic functions.
Fluid and gas mechanics. The possibility of estimation
of parameters of unbalanced structures arising at fluid displacement
in porous medium by means of physical parameters of such media is
shown. The problem is theoretically solved on the basis of dependence
of resistance factor on the frequency of applied pressure.
The possibility of regulation of development of unbalanced fractal
structures by means of local pressure at the interface is proved,
and oilgasfield technological method was worked out for the realization
of the obtained effect.
Stability and oscillations analysis method of non-homogeneous elastico
- plastic structural elements with regard for environment is worked
out.
Mechanics of deformable solid. Analytic solution
of nonlinear inverse boundary problem of axially symmetric large
elastic deformations of circular orthographic membranes accepting
preassigned form of a segment of rotation of a body under the action
of fluid and normal loading is obtained.
The problem on eigen oscillation of a circular cylindric shell strengthened
by a longitudinal rigidity ribs situation at the same distance from
one another and filled by linear elastic medium, is solved.
Under homogeneous boundary conditions on the ends the problem on
stress -strain state of variable thickness transversally isotropic
plate restricted by two conic and two spherical surfaces at its
axially symmetric stretch - compression, is solved.
Equations of net motion in natural coordinates were derived.
Strong break front at self - model motion was found.
The problem on unstationary waves propagation in right prism was
first considered and exact analytic solutions were found for concrete
cases. Some facts discovered previously only experimentally for
example, fact on propagation of main energy along the axis with
rod velocity involving free lateral surfaces and etc. were affirmed
theoretically.
Motion of circular inclusion containing elastically fixed mass with
acoustic and elastic medium was studied.
Velocity potential, forces of medium reaction, elastic potentials
and inclusions displacements were also determined.
Effective mathematical theory of cracking of corroding materials
under mechanical stress was worked out.
The theorems admitting to represent the solutions of the problems
of linear and a class of nonlinear elasticity theory by the solutions
of the corresponding problem of elasticity theory were proved.
Mathematical theory of simulation of destruction of constructions
made of visco - elasticoplastic material was suggested.
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