Известия Академии наук Республики Таджикистан. Отделение физико-математических, химических, геологических и технических наук, №1(178), 2020 г. |
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Скачать | S.A.Iskhokov , O.A.Nematulloev | 7-15 | On eigenvalues of a class of non-selfadjoint degenerate elliptic operators in a bounded domain |
We study a class of higher-order elliptic differential operators with summable coefficients in a bounded domain with power-law degeneracy along the entire boundary of the domain. It is proved that these operators have a discrete spectrum and asymptotic of their eigenvalues is studied. |
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Ключевые слова: elliptic operator; power degeneration; eigenvalue; bounded domain. | |
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Скачать | O.A.Jurakhonov | 16-28 | On exact inequalities type of Jackson-Stechkin
in hilbert weight space L(Q) |
We evaluate the exact inequalities Jackson-Stechkin type obtained between the best "angle" square approximation, composed of real orthogonal algebraic polynomials, and integrals containing a generalized modulus of continuity of functions generated by a particular shift generalized operator in the metric of the space with weight on the function classes of two variables , integrable with a square on the rectangle with finite norm |
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Ключевые слова: orthogonal polynomials; generalized modulus of continuity; generalized shift operator; quasi-polynomials; best aproximation. | |
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Скачать | F.Raimzoda | 29-36 | About simultaneous approximation of functions and its derivatives by trigonometric polynomies in L |
The problem of simultaneous approximation of functions and its successive derivatives by trigonometric polynomials in on some classes of functions defined by averaged values of the norm of the first-order difference is solved. |
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Ключевые слова: best approximation; trigonometric polynomial; simultaneous approximation of functions and its derivatives. | |
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Скачать | N.Rajabov , S.B.Zaripov | 37-43 | To theory one class of simmetrical two dimensional volterra type integral equation with one boundary and one interior supersingular lines |
In this work, we investigate one new class of the two dimensional symmetric Volterra type integral equations with one boundary and one interior super singular lines. |
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Ключевые слова: two dimensional integral equation; supersingular lines; symmetrical equation; asymptotic conditions. | |
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Скачать | M.Sh.Imom , Kh.Kh.Muminov , V.L.Romodanov , F.Rahimi , S.F.Odinaev | 44-49 | Research of the efficiency of the digital analysis
of loading a neutron channel for various scintillation counters |
A digital analysis of the neutron channel loading for liquid and crystalline scintillators is investigated. We used 2 sources of gamma quanta and made changes in the distance of sources of gamma quanta and determined changes in the number of neutron pulses. Scintillator BC - 501, compared with the EJ - 309 scintillator and the Stilben crystal scintillator, showed that before loading 3×10pulses/s the number of neutrons does not change and the responses of gamma quanta do not fall into the neutron responses. |
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Ключевые слова: non-destructive analysis; analog-digital converter; nuclear fissionable materials; photomultiplier tubes - photomultiplier tubes; nanosecond. | |
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Скачать | A.A.Adhamov , F.Kholmurodov | 50-56 | Bulk refraktion of two intersecting lazer beams
in cadmium sulfide at low temperatures |
The physical effect is studied in the implementation of which it becomes possible to control a strong light beam using anintersecting weak laser beam propagating in a semiconductor crystal with a narrow gap, possessing piezoelectric properties in a strong magnetic field and at of both liquid nitrogen and liquid helium low temperatures. In this regard, it seems appropriate to talk about «optical analogous of the transistor».
All calculations were performed for a semiconductor cadmium sulfide crystal transparent to the incident radiation. |
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Ключевые слова: laser beams; electrons flow; scattering; electromagnetic wave; piezoelectric semiconductor; wave intensity. | |
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Скачать | Kh.Gafurov , H.A.Toshhodzhaev | 57-64 | Mechanism high stability of time structure
in mode-locked laser |
Presented results are explained the mechanism formation a complex structure of laser radiation in the mode locked laser. The estimation results of time and frequency characteristics showed that high stability, time structure, is provided by saturation processes. The shape of an individual light pulse at the boundary region existence of the mode-locking regime indicates the fine structure spectrum of the laser transition. |
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Ключевые слова: laser; mode locking; period; frequency; light pulse; beat signal; relaxation time. | |
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Скачать | Sh.Кh.Rajabov , D.A.Saidaliev , H.Alisher , E.Abuali , A.S.Faizulloev | 65-72 | The тechnology of reception cryolite, fluoride and fluid acid of aluminum from alumina-, fluorine containing aluminum production wastes |
In the present article technology of reception cryolite and fluoride of aluminum from alumina and fluorine containing wastes of aluminum production is described. The physical and chemical analysis is carried out on optimum condition of process passing and defined compositions of raw materials and products. |
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Ключевые слова: aluminum production; alumina and fluorine containing wastes; aluminum manufacture; acidic decomposition; fluoric acid; criolite and aluminum fluoride production. | |
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Скачать | P.R.Ibrohimov , I.N.Ganiev , F.A.Rahimov , Z.R.Obidov | 73-77 | Influence of additives of chrome on anode behaviour Zn0.5Al alloy, in alkaline environment |
In paper results potentiostatical researches influence of additives of chrome on anode behaviour of Zn0.5Al of alloy, in the alkaline environment are presented. It is shown, that speed of corrosion alloy zinc-aluminium decreases at 2.0-2.5 times at the additives in it 0.01-0.1 wt.% Cr. |
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Ключевые слова: Zn0.5Al alloy; chrome; potentiostatically method; HCl electrolyte; corrosion potential; corrosion rate. | |
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Скачать | R.S.Mirzoeva , D.S.Mukhiddinov , Kh.H.Avloev , D.Kh.Khalikov | 78-83 | Sorption of metal ions by pectin hydrogels |
Using the methods potentiometric and conductometric titration, the potential centers of adsorption of pectin polysaccharides obtained from extracts of apples, citrus, peach, pectin baskets sunflower and Sodium pectate with respect to metal cations are studied. According to the sorption of ions of Mead pectic substances, hydro gels on their aqueous environment and in the acetate buffer are determined by the value of the maximum capacity qm of hydro gels, the adsorption equilibrium constant (К) and the change in free energy (dG=-RTlnK). The data obtained indicates a significant role of the hypothetical ion exchange process in the studied systems and an increase in the sorption activity of the studied natural polymers in the pH region near the pK of the corresponding carboxyl groups. |
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Ключевые слова: adsorption centers; pectins; sodium pectate; galacturonic acid; potentiometry; conductometry; sorption; adsorption; equilibria; free energy. | |
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Скачать | M.D.Boboyorov , B.B.Barotov , F.A.Khamidov , Sh.R.Murodov , U.M.Mirsaidov | 84-88 | Thermodynamic analysis of flowing processes during sulfuric acid leaching of the ores from Western Tajikistan and Central Tajikistan deposits |
The article provides an analysis of the thermodynamic characteristics of the processes occurring during the leaching of uranium-containing minerals in the Western Tajikistan and Central Tajikistan deposits with sulfuric acid. It is shown that the Gibbs energy values in the considered processes involving minerals of the above deposits confirm the occurrence of all possible reactions. |
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Ключевые слова: thermodynamic characteristics; sulfuric acid; Gibbs energy; leaching; minerals; uranium-containing ores. | |
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Скачать | Y.K.Kudratulloev , K.S.Mabatkadamzoda | 89-95 | Complex formation of silver (I) with thiopirine in water-alcohol solutions |
Using the method of potentiometry, we studied the complexation of silver (I) with thiopyrine (TP) in aqueous-alcoholic solutions containing 25, 50 and 75 vol. % methanol and ethanol at 298.15 K and an ionic strength of 0.1 mol/l reated by NaClО. It was found that Ag (I) with thiopyrin in solutions containing different amounts of non-aqueous solution forms a complex particle of the composition [Ag(TP)]. The complex formation and stability of the Ag (I) complex depending on the content of non-aqueous solvent were studied. The total formation contant and the Gibbs energy of the formation of the [Ag(TP)] complex were calculated. It was shown that with an increase in the alcohol content in the solution, the stability of the formation constant decreases. The obtained data on the calculation of the Gibbs energy value showed that the formation of a three-mixed complex of silver (I) with TP is accompanied by a negative value of DG. With an increase in the volume percent of alcohol of the values, the Gibbs formation energy of the complex [Ag(TP)] increases. It has been shown that the total constant for the formation of complex [Ag(TP)] in water is greater than in water-alcohol solutions at 298.5 K |
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Ключевые слова: silver (I); thiopyrine; organic solvent; ionic strength; methanol; ethanol; potentiometric titration; complexation; general formation constant; Gibbs energy. | |
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Скачать | Sh.A.Faizulloev | 96-103 | Accuracy assesment of classification of remotly sensed data in GIS technology, a case study of the HPP cascade area on the Vakhsh river |
The article deals with the classification of images in order to obtain land cover data of the study area using supervised image classification and estimation of the accuracy of the output material using GIS technologies. |
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Ключевые слова: remote sensing; land cover; land use; GIS technology; estimation of classification accuracy; error matrix and Kappa coefficient. | |
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Скачать | A.K.Oshurmamadov | 04-112 | Geochemical features and geodynamic formation
conditions volcano-plutonic association of the Southern Hissar zone |
The article presents data from geochemical studies of the material composition of volcanics and plutonites of Southern Gissar and shows that they are mainly represented by acidic rocks with superclark contents Cr, Сo, Cu, Zn, Rb, Y, Sn, Cs, and REE in comparison with leucocratic granites of the granitoid series, Sn, Y, Zn, Cu, Nb, Ta, U, Th are enriched. |
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Ключевые слова: volcanic; plutonites; subduction; collision; association; luchob series; hochiler complexs. | |
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Скачать | Sh.A.Mirzoev | 113-121 | Modification of the system of Boussinesq equations for solving some problems in pressure pipes and open channels |
A closed system of equations of the average Reynolds-Boussinesq motion with an additional differential term, vortex viscosity, is proposed. New solutions to one-dimensional problems of turbulent flow in pressure pipes of circular cross section and in channels with a free surface are obtained. |
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Ключевые слова: system of equations of turbulence; incompressible fluid; Newton's molecular viscosity; Boussinesq vortex viscosity. | |
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Скачать | | 122-127 | |
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Ключевые слова: . | |
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Скачать | | 128-131 | |
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Ключевые слова: . | |
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