Доклады Академии наук Республики Таджикистан, том 62, №01-02, 2019 г.
|Article title and abstract||Pages|
|Rakhmonov Z.Kh., Rakhimov A.O., Rakhmonov F.Z.|
Short cubic double exponential sums with close in «order»
In minors arcs a nontrivial estimate of double trigonometric sums of the form is found
in which the amounts constitute a double amount, «close» in order.
Key words: short exponential sum with primes; minor arcs; short double sum; Waring-Goldbach problem.
|Shabozov M.Sh., Farozova A.D.|
On best approximations of some classes of periodic functions in L
In the metric L, exact inequalities are obtained that relate the best approximations of 2π-periodic functions and their a sequence of derivatives of trigonometric polynomials with integrals containing the moduli of continuity of higher orders derivatives of these functions. The values of n-diameters classes of functions defined by moduli of continuity of derivatives functions' are calculated.
Key words: best approximation; module continuity; n-widths of sets.
|Safarov D.S., Abdulvokhidi О.|
Generalized quasi-double-periodic solutions of one elliptic systems of second-order equations on a plane
In the work for one class of second-order elliptic systems on the plane, we found generalized quasi-double-periodic solutions with given poles using the Weierstrass elliptic functions. In this case, the methods of double-periodic generalized analytic functions are used.
Key words: doubl-periodic function; quasi-double-periodic solution; Weierstrass dzeta-function; cyclic constants; the system of the Cauchy-Riemann equation; regular solutions.
|Kabilov M.M., Kholov O.A.|
Analytical solution of the model problem of filtration combustion of gases
In this paper a method for obtaining an analytical solution of a model problem of filtration combustion of gases are presents. This solution is a function of temperature and the fraction of the concentration to the longitudinal coordinate and under the condition of similarity of the profiles of the temperature of the system and the fraction of the concentration of the component of the mixture it is obtained. The similarity condition consists of the product of the Lewis number of the gas component and some parameter depending on the wave velocity and other constants. In addition, formulas for temperature and density are obtained for a maximum temperature gradient. To determine the speed of the combustion wave, it is proposed to use the previously obtained equation. The equation of state of a gas mixture is determinated in the form of a dependence of the mixture density on its temperature.
Key words: temperature; concentration; diffusion; wave speed; chemical reaction; filtration combustion; combustion wave; Lewis number; porous medium; the equation.
|Usmanov Z.D., Dovudov G.M.|
Studying the efficiency of the use of consonantal letter
in tajik written language
It is established that а fully consonantal letter is not understandable to a qualified Tajik reader. But if it is supplemented by the three highest frequency tajik vowels, the new object becomes understandable at the level of more than 92%.
Key words: Tajik language; consonantal letter; decoding.
|Kokhirova G.I., Babadzhanov P.B., Khamroev U.Kh., Latipov M., Faizov Sh.B.|
Perseid meteoroids by Tajikistan fireball network observations: I. Dynamical features
Photographic observations of the Perseid meteor shower activity were carried out by the Tajikistan fireball network at the maximum of the shower during 2007-2011. 29 Perseid fireballs were registered over this period. The fireballs were produced by meteoroids with sizes larger than small dust particles which form meteor phenomenon. As a result of astrometric and photometric reduction of the obtained observational data the atmospheric trajectories, velocities, orbits, light curves of fireballs as well as the photometric masses and densities of meteoroids were determined. Detected fireballs present sufficient data set for analysis of physical and dynamical properties of the large-sized Perseid meteoroids. The results of investigation of their dynamical features are presented in this paper.
Key words: meteor shower; fireball; atmospheric trajectory; height; radiant; orbit.
|Ibadinov Kh.I., Konovalova N.A., Davruqqov N.Kh.|
Groups of meteorite-producing bolides and ordinary chondrites in cometary-like orbits
In the paper the results of existence of groups of meteorite-producing bolides and meteorites type of L3.5 - H5 in the earth-crossing JFC orbits are presented. The similarity of orbits of meteorite-producing bolides and meteorites in the groups based on two orbital similarity criterions Dand D was established.
Key words: group; bolide; meteorite; ordinary chondrite; orbit; comet; Jupiter family.
|Salikhov T.Kh., Melikkhudzha N., Mahmalatif A.|
Contribution of substrate absorption to the characteristics of the fundamental harmonic of nonlinear photoacoustic response
A theory of the generation of the fundamental harmonic of a nonlinear photoacoustic response has been proposed for the cases when the substrate, along with the sample, is absorbing. The general expression for the complex amplitude of temperature perturbations in the buffer gas is obtained. The case when the sample is thermally thin and transparent is investigated in detail. For this case, expressions are obtained that describe the features of the generated nonlinear PA-signal at the modulation frequency.
Key words: photoacoustic; thermal nonlinearity; optoacoustic.
|Muminov Kh.Kh., Muhamedova Sh.F.|
Dissipative brethers of scalar nonlinear schrödinger equation with repulsion potential
The results of a series of numerical experiments on the evolution of a two-soliton solution of a nonlinear Schrödinger equation with a repulsion potential, in the presence of dissipation and pumping, have been carried out. It is shown that in the presence of dissipation and pumping, even a fixed, static two-soliton solution exhibits a breather dynamics. Analysis of the phase portrait of the system shows the formation of a classical attractor, leading to the formation of a stable conservative structure - a long-lived dissipative breather.
Key words: dissipative solitons; repulsive potential; scalar nonlinear Schrödinger equation; dissipation; pumping; breather; strange attractor.
|Saliev M.A., Yumaev N.R., Juraev E., Akhmedov Kh.M.|
Evaluation of the influence of climate conditions on the efficiency of work of the solar photoelectric installation
The influence of the climatic conditions of the terrain on the efficiency of SFEU operation of the installed capacity of 400 W in the real conditions of Khujand of the Republic of Tajikistan (RT) is investigated. The evaluation of the reduction in the SFEU electric power production due to the cloudiness and high FEM temperature is given based on the FEM temperature monitoring data and the terrain air. It is shown that the minimum efficiency values correspond to the maximum FEM temperature at noon. The average daily FEM efficiency is 0.15 (15%) in the summer months and 0.2 (20%) in the winter months.
Key words: climatic conditions; installed capacity; solar radiation; cloud cover; solar photovoltaic system; power generation; photoelectric module.
|Barotov A.M., Nazarov F.A., Kurbonovа A.S., Nazarov Sh.B., Мирсаидов У.М.|
Estimation of the process of sintering of borosilicate ore with various reagents
The estimation of sintering process of borosilicate ore of Ak-Arkhar field of Tajikistan with various reagents is presented. The advantage of calcium chloride as the most accessible and cheap reagent in the process of sintering is shown.
Key words: sintering; borosilicate ore; calcium chloride; sodium hydroxide; estimation.
|Kholov Kh.I., Samikhov Sh.R., Zarifova M.S., Bobomurodov O.M.|
Studying the extraction gold from flotation tailings
of djijicrut deposit narrow level by thiourea
The results of researches of gold leaching from mineral processing tailings of gold containing antimony-mercury ore by thiourea are presented. It was shown that after pretreatment of tailings gold is leaching by thiourea satisfactory from them.
Key words: leaching technology; flotation; leaching; antimony mercuric goldcon taining ore; gold containing solution.
|Zokirov F.Sh., Ganiev I.N., Berdiev A.E., Sangov M.M.|
Influence of strontium on the anodic behavior of the alloy AK12M2
An experimental study of the effect of strontium alloy anode behavior AK12M2 among the electrolyte sodium chloride. It is shown that the addition of strontium to reduce the speed of 1.5 times the original alloy corrosion AK12M2. As the concentration of chloride ions in the electrolyte NaCl pitting corrosion potentials and shifted in the negative region, the corrosion rate increases.
Key words: AK12M2 alloy; strontium; anode behavior; free corrosion potential; pitting potential; corrosion rate; NaCl electrolyte.
|Sirodjidinov E.N., Ganiev I.N., Obidov Z.R.|
High-temperature oxidation of Zn55Al alloy, doped with thallium, in the firm condition
In this paper the results of research kinetic the high-temperature oxidation of Zn55Al alloy, doped with thallium, in a firm condition are resulted. It is shown that additives of an alloying component slightly increase oxidability of alloy Zn55Al.
Key words: Zn55Al alloy; thallium; thermo gravimetrical method; high-temperature oxidation; speed of oxidation; energy of activation.
|Naimov N.A., Aminjoni G., Ruziev J.R., Boboev H.E., Salimova P.T., Safiev H.|
The kinetics of the sulfatization process stavrolit-muscovitic shale Tajikistan
In this article the results of research of kinetic parameters of the process of sulfatization stavrolit-muscovitic shale Kugovad deposits is presents. During the sulfatization process and kinetic calculations, the apparent activation energy, the velocity constant and the pre-exponential factor of the Arrhenius equation were determined, which indicate the process in the mixed (mainly diffusion) region.
Key words: stavrolit-muscovitic shale; alumina; sulfatization; aluminium hydroxide; coagulant; activation energy; Arrhenius equation.
New data on the avifauna of the Zorkul Nature Reserve
The article contains generalized materials on the avifauna Zorkul reserve. Brought new data to qualitative feature avifauna. It is established 126 bird species are found in the reserve, 26 of which are marked for the first time in the reserve.
Key words: Zorkul reserve; Upland Buzzard; Black Stork; Tibetan Snowcock; Snow Pigeon; White-capped Redstart.
|Abdullaev Kh.A., Solieva B.A., Khakimova R.Sh., Saidnabiev M.M.|
Number of leaves as a traits of vegetation period and fruiting times in cotton
In this paper the results of study of vegetative periods and number of leaves per plants in inbred lines of upland cotton are presents. It is shown that in inbred lines who have a short vegetative periods as a rule number of leaves per plants is small. Number of leaves per plants is recommend as a diagnostic traits for selection of early fruiting forms.
Key words: cotton Gossypium hirsutum L.; inbred lines; leaf; number of leaves; vegetation period; fruiting.
|Pirmatova D.A., Dodkhoeva M.F.|
Features of the pregnancy course and childbirth in pregnant women with GDM in combination with ahemia
Researches, conducted in the city of Dushanbe revealed a high incidence of pregnancy complications and the course of childbirth in pregnant women with GDM combined with anemia. In addition, analysis of results of the study showed a high concentration of AlAT and AsAT in the blood of pregnant women with GDM in combination with anemia, a high incidence of preterm labor, cesarean section, induction of labor due to the severity of complications compared with the control group, as evidenced by the adverse outcomes resulting in the combination of GDM with anemia in respondent women.
Key words: gestational diabetes mellitus (GDM); anemia; extragenital pathology; pregnancy; outcomes.