Доклады Академии наук Республики Таджикистан, том 63, №05-06, 2020 г. |
File | Article title and abstract | Pages |
|---|
| |
Download | Rakhmonov Z.Kh., Sobirov A.A., Fozilova P.M. | 279-288 | Behavior of short cubic exponential sums with primes
in a small neighborhood of the center of major arcs |
For , , in a neighborhood of the center of major arcs, an asymptotic formula of the form
is proved. |
|
Key words: short exponential sum with primes; major arcs; density theorem; Dirichlet L-function. | |
|
Download | Talbakov F.M. | 289-293 | About absolute convergence offourier series of almost periodic functions in the uniform metric |
In this paper the question of sufficient conditions for absolute convergence of Fourier series of uniform almost periodic functions, in the case where the Fourier exponents have a single limit point at zero are investigates. The continuity module as a structural characteristic of the Laplas transform is used. |
|
Key words: almost periodic functions; Fourier series; spectrum functions; Fourier coefficients; Fourier exponents; limit point at zero; Laplas transform. | |
|
Download | Yusupov G.A., Zargarov J.J. | 294-299 | On the best joint approximation of analytical functions in Hardy space |
In this paper, a new exact inequalities between the values of the best joint root-mean-square approximation of functions analytic in the unit disk and integrals containing the averaged values of the r-th order moduli of continuity of the boundary values in the Hardy space are found. |
|
Key words: analytic function; modulus of continuity of the r-th order; best approximation; Hardy space; sharp inequalities. | |
|
Download | Saynakov V.D. | 300-308 | On the best mean approximation with averaged polynomials of two variable functions |
In this paper the sharp constant of Jackson-Stechkins inequality between the best approximation of two variable periodic functions with averaged trigonometric polynomials and modulus of continuity of partial derivatives of higher order functions was found. The sharp values of Kolmogorovs and linear quasiwidths of some classes of periodic functions of two variables given by modulus of continuity of partial derivatives in space were calculated. |
|
Key words: sharp constant; Jackson-Stechkin inequality; the best approximation; module of continuity; quasiwidth. | |
|
Download | Iskhokov S.A., Haknazarov K.E. | 309-315 | On solvability of variational dirichlet problem for
non-divergent form degenerate elliptic operators
in a bounded domain |
We prove an analogue of the Garding inequality for a class of non-divergent form elliptic operators in a bounded domain of the -dimension Euclidian space with degeneracy along the entire boundary of the domain. Using this inequality we study solvability of the variational Dirichlet problem for such operators in a weighted space, the set of compactly supported infinitely differentiable functions is dense in which. |
|
Key words: Garding inequality; variational Dirichlet problem; non-divergent form elliptic operator; power degeneration; bounded domain. | |
|
Download | Usmanov Z.D., Kosimov A.A. | 316-321 | Automatic search for anagrams of n-gram word-forms |
For the model collection of works, the effectiveness of using a computational algorithm both for finding an anagram to a given n-gram word-form and for an exhaustive description of the entire variety of anagrams containing in an arbitrary text is confirmed. |
|
Key words: text; word- form; n-gram; anagram. | |
|
Download | Kabilov M.M., Kholov O.A. | 322-327 | Numerical study of filtration combustion of gas with the generalized Lewis number |
In this work a numerical study of the model problem of filtration combustion of gases with a generalized Lewis number is devoted. The considered problem in a particular case becomes the problem of the structure of the flame front for an arbitrary Lewis number. For the numerical solution of the problem, the fourth-order Runge-Kutta method and the Delphi-7 programming language are used.
The calculations show the unstable behavior of the function of the fraction of the reacting component depending on the generalized Lewis number, except when this number is equal to unity. |
|
Key words: temperature; concentration; diffusion; wave speed; chemical reaction; filtration combustion; combustion wave; Lewis number; porous medium; the equation. | |
|
Download | Kokhirova G.I., Ivanova О.V., Rakhmatullaeva F.Dzh., Baransky A., Buriev A.M. | 328-342 | Results of observations of the dual object 2008GO98 (362Р) in 2017 |
In this paper the results of optical observations of the dual object 2008 GO98 (362P), carried out at the Sanglokh Observatory and Astronomical Observatory named after T. Shevchenko Kiev National University are presents. At the time of monitoring, the asteroid showed a sign of comet activity in the form of a dust coma and tail, the presence of which were confirmed by the results of the study of image morphology. The apparent and absolute magnitudes of the asteroid in the filter R determined, their gradual decrease during the observation period is shown - from 13.97 to 14.53 absolute magnitudes, which indicates a decrease in activity by the end of monitoring. The estimate of the effective diameter of the asteroid from our observations of ~7 km is consistent with the available data. The new data obtained suggest the cometary nature of the object. The new data obtained have suggested the cometary nature of the object. Asteroid activity did not affect the stability of the orbit. |
|
Key words: asteroid; comet; activity; observations; photometry; light curve; diameter; morphology; astrometry; coordinates; orbit. | |
|
Download | Ibragimov A.A. | 343-349 | Determination of solar wind velocity from observations of plasma tails of comets |
The solar wind velocity from observations of the plasma tail of comet C/2014 Q2 (Lovejoy) was determined. An algorithm for calculating cometocentric coordinates by the Stumpf method is presented. The conditions for increasing the accuracy of determining the cometocentric coordinates are shown. It is suggested that the broadening of the plasma tail by the Sun's gravity can affect the aberration of the tail axis relative to the extended radius-vector. |
|
Key words: comet; plasma tail; solar wind; cometocentric coordinates. | |
|
Download | Rahimi F., Abdulloev Kh.O., Devonakulov Sh.A., Niyozov B.O. | 350-356 | Dissipative solitons of the Ginzburg-Landau equation with cubic nonlinearity |
In this paper dissipative solitons of the cubic Ginzburg-Landau equation arising from the interaction of linear and nonlinear complex dispersions are investigated. Its localized solution of general form for given sets of parameters has a fixed amplitude. Received his solutions in the form of solitons with limited amplitude. |
|
Key words: dissipative solitons; nonlinearity; localization; uniqueness; amplitude; width; frequency; set of solutions; stationary solutions; reality. | |
|
Download | Rashidov D., Tabarov S.Kh., Voznyakovskii A.P., Sodikov F.Kh., Aknazarova Sh.I. | 357-362 | The effect of graphenoxides on the structure, thermal and mechanical properties of polyethylene |
Nanografenoxides obtained by the method of self-propagating high temperature synthesis (SHS) were used as modifying additives of low density polyethylene. It is shown that the introduction of graphenoxides obtained by SHS into polyethylene is accompanied by uniform changes in the structure, mechanical and thermophysical properties of the samples. Studies have found that with an increase in the concentration of nanoparticles in polyethylene, a sufficiently large conservation of the resource of mechanical properties is observed, which is important for practical technology. Such behavior of the mechanical properties of nanocomposites indicates a change in the physical state of amorphous regions of the polymer, i.e., their transition from a highly elastic state to a glassy one. |
|
Key words: polymer; graphenoxid; composite; structure; properties. | |
|
Download | Khamidov I., Valiev J., Karimov Kh.S., Akhmedov Kh.M. | 363-367 | Development and investigation of a multicomponent structure based on organic and inorganic semiconductors InGa/OAK/GaAs/C |
A multicomponent structure based on the organic and inorganic semiconductor InGa / OAK (NaCl) / GaAs / C is developed and its current-voltage characteristic is studied. The rectification effect is revealed and the dependence of the rectification coefficient of the investigated heterostructure on the magnitude of the voltage is established. It is shown that based on this multicomponent structure it is possible to manufacture diodes for use in electronics. |
|
Key words: organic semiconductor; inorganic semiconductor; rectification coefficient; heterostructure; current-voltage characteristic. | |
|
Download | Gaibullaeva Z.H., Nasimov G.T., Asrorov B.I., Bahriddinzoda Sh.B., Sharifov A. | 369-372 | Heterogeneous processes of lead reduction from galenite-containing concentrate by gases |
In this article the processing of lead-zinc concentrate with atmospheric oxygen and the reduction of the resulting products of processing with reducing water gas are presents. This process is heterogeneous, where one of the mandatory stages is the transfer of gases to the surface of solid particles. Concentrate particles make up a granular layer with intergranular porosity, they are washed by gas flows during lead reduction processes. |
|
Key words: recovery; heterogeneous process; diffusion; externally kinetic region. | |
|
Download | Aminjoni G., Naimov N.A., Ruziev J.R., Boboev Kh.E., Nazarov Sh.B., Safiev H. | 373-379 | |
In this work the physicochemical aspects of processing flotation muscovite concentrate using the sulfatization method is present. The optimal technological parameters of sulfatization processes (temperature, process duration, concentration and dosage of sulfuric acid) and water treatment of sulfated sample (temperature, duration and ratio of solid to liquid phases) were determined in order to obtain aluminum sulfate, aluminum hydroxide and alumina. Sulfated sinter can be used as a crude coagulant during its subsequent processing, you can get sodium aluminate and aluminum hydroxide - the feedstock for the production of fluoride salts, as well as alumina - the main feedstock for the production of aluminum. |
|
Key words: flotation muscovite concentrate; sulfatization; aluminum sulfate; aluminum hydroxide; alumina; fluoride salts. | |
|
Download | Sabirov А.А. | 380-387 | New primitive foraminifera from carboniferous deposits of Yura mountain (Central Tajikistan) |
The five a new species of primitive Foraminifera belonging to the families Parathuramminidae, Archaesphaeridae and Tuberitinidae in the Carboniferous deposits of Yura mountain have been identified and described. |
|
Key words: Foraminifera; Carboniferous system; Tournaisian stage; Visean stage; Central Tajikistan. | |
|
Download | Oyzoda N.Kh., Solieva B.A., Khakimova R.Sh., Maniyazova N.A., Abdullaev Kh.A. | 388-392 | Depedense of number and weight of the cotton bolls from colour and type of the leaf |
In this article the results of study depedense number and weight of the cotton bolls from colour (color) and type (shape) of the leaf are presents. It is shown that the cotton line L-3 with antocyan coloration leaves had a little number of burst bolls and common yield. Genotypes with green and dark green leaves had a two-time greater harvest than lines with antocyan leaves. It is concluded that the value of economic yield of cotton is depedense from colour leaf. |
|
Key words: middle stable cotton Gossypium hirsutum L .; line; shape and colour of leaf; number and weight of the bolls; economic yield. | |
|
Download | Rustamova M.S., Odinaev Sh.F. | 393-399 | Clinical assessment of ultrasound under different chronic kidney disease stages developed in the basis of diffuse glomerulonephritis |
In this paper the results of integrated Doppler ultrasound of kidneys with parenchyma thickness measurements, the cortical layer, determination of the cortical echogenicity degree and vascularization in 150 patients with different stages of chronic kidney disease, which developed as a basis of diffuse glomerulonephritis are presented. The authors conciderthat, the result of study allows estimating the mechanisms of progression of CKD stages. The obtained results should be taken into account while assessing the gravity of process, forecasting and during treatment strategies of different CKD stages. |
|
Key words: chronic kidney disease; chronic glomerulonephritis; parenchyma; cortical layer; cortical echogenicity; vascularization; glomerular filtrate rate; Doppler research. | |
|
