Известия Академии наук Республики Таджикистан. Отделение физико-математических, химических, геологических и технических наук, №2(179), 2020 г.
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|Kh.Kh.Muminov , Sh.F.Muhamedova |
Dissipative solitons of the vector nonlinear Shredinger equation with a self-consistent potential in the presence of pumping
For the first time by means of numerical simulation dissipative solitons of the vector nonlinear Schrödinger equation (the system of two equations) with a self-consistent potential is obtained. An analysis of the dynamics of evolution of multisoliton solutions shows that under dissipation and pumping, the significant breather dynamics with a high degree of stability is exhibited. Phase trajectories densely fill a limited region of the phase space. The cross section of the Poincare map gives evidence on the formation of an attractor of the limit cycle.
Ключевые слова: n-soliton solution; pumping; dissipation; vector nonlinear Schrödinger equation; breezer; dissipative soliton.
|A.K.Kayumov , S.F.Abdullaev , D.A.Kayumova , N.Kh.Minikulov |
Comparative analysis of the content of heavy metals
in the soils of glacial lakes
The results of a study to determine the content of heavy metals (HM) in the form of free elements or oxides are presented. An analysis of the elemental composition of the samples by X-ray fluorescence analysis for Karakul samples indicates an excess from the MPC by 1.41 times, and relative to Clark soil by 1.88-5.88 times. In the soil of Karakul TiO2 doesnt find. The copper content exceeds Clark soil by 2.37-2.48 times. The lead content exceeds Clark soil by 1.68-2.27 times. The remaining HM do not exceed the values of MPC, Clark soil and Clark earth punishment. The soil of Karakul is significantly contaminated with lead than the soil of Iskanderkul. The content of cobalt 1.91 and lead 1.83 times more in Karakul than in Iskanderkul. Nickel is 2.27 times, iron is 1.76, zinc and vanadium are 1.26 times more in Iskanderkul than in Karakul.
Ключевые слова: glaciers; aerosols; lake; bottom sediment; soil; heavy metals; pollution.
|M.N.Rakhmatov , V.A.Maslov , S.F.Abdullaev , U.Madvaliev |
Comparison analysis of the content of heavy metals in the composition of soils and aerosol of north tajikistan
The article discusses the results of experimental studies between the elemental composition in samples of atmospheric aerosol and soils of northern Tajikistan for the period from 2013 to 2019. According to the results of a comparative analysis of measurements of the elemental composition of aerosol and soils, their interannual variability was revealed, indicating that the features of temporal variations are regional in nature and are determined by the dynamics of changes in the content of heavy metals when changing air masses. The elemental composition was determined by the method of X-ray fluorescence analysis. The soil content of elements of the first (arsenic, lead, zinc) and second hazard class (copper, nickel, cobalt, chromium) exceeds the MPC in many areas, while the sources of pollution are mainly anthropogenic in nature.
Ключевые слова: atmospheric aerosol; elemental composition of aerosols; soils; heavy metals; pollution.
|А.Tofik , S.М.Ahmad , Kh.S.Karimov , N.R.Yumaev , Kh.M.Akhmedov |
Research of solar thermoelectric generator
with two-stage concentrator
A solar thermoelectric generator with a two-stage concentrator (a conical parabolic concentrator and a Fresnel lens) is studied. A thermoelectric generator made of bismuth telluride (Bi2Te3) TEC-12706 (TEG) was used. Electrical efficiency was 0.421%, and thermal 54.34%. The total efficiency of the thermoelectric generator, which is the sum of the electrical and thermal efficiency, was 54.36% for a focal length of 13 cm. It was shown that the maximum power of a single-stage parabolic diffraction thermoelectric generator is 0.013 W, which is 5 times less than the maximum power of 0.069 W obtained using two-stage concentrators.
Ключевые слова: two-stage concentrator; efficiency; Fresnel lens; focal length; thermoelectric generator; Seebeck effect; electric and thermal power.
|V.A.Novozhenov , I.N.Ganiev , S.V.Makarov |
The structure and properties of the materials on the base niobium and germanium alloys and thin films
Using the methods of differential thermal (DTA), X-ray phase and energy dispersive analyzes, the structure and properties of materials based on alloys and thin films of niobium with germanium are studied. The synthesis conditions and temperature ranges of oxidation stability were determined from DTA data. The stability of the films in air was studied, keeping them at room temperature for 1-3 months and when heated at 100 and 250 ° C for 2 hours. The phase composition of the alloys was determined by the XRD method. X-ray phase analysis of thin films showed that the thermodynamically most stable compounds in the system are usually deposited on the surface of the substrate during deposition from the gas phase.
Ключевые слова: alloys; thin films; intermetallic compounds; phase; surface.
|P.R.Ibrohimov , I.N.Ganiev , F.A.Rahimov , Z.R.Obidov |
Kinetic oxidation of Zn0.5Al alloy, doped with molybdenum, in the firm condition
By the thermo gravimetrical method the interaction of Zn0.5Al alloy, doped with molybdenum, with air oxygen in an interval to temperature 523-623K in the firm condition was investigated. Kinetic parameters of process of high-temperature oxidation of alloys are defined. Showed, that additives of molybdenum within 0.01-0.1 wt.% slightly increase oxidability of an initial alloy, and products of oxidation of alloys are oxides ZnO, AlO, MoO, ZnO∙MoO.
Ключевые слова: Zn0.5Al alloy; molybdenum; thermo gravimetrical a method; high-temperature oxidation; speed of oxidation; energy of activation.
|Sh.Кh.Rajabov , R.E.Asalov , A.S.Fayzullaev , I.Emomov |
Innovative technologies for the production of flux from local raw materials and production waste
The paper presents the results of studies on the development of innovative technology for the production of flux from local raw materials and production waste for foundry production of aluminum. The optimal parameters for the implementation of technological processes are found, a physicochemical analysis of these wastes and their products is carried out. On the basis of studies carried out in the laboratory, a technological scheme was developed for the production of flux of GU «NIIM» from the waste from the sludge fields of OJSC «Tajikkhimprom» and the local mineralogical raw materials of the fluorite of the «Takob» field.
Ключевые слова: innovative technologies; flux; foundry; fluorine-containing raw materials; waste; environment; sludge fields; aluminum refining; slag; active additives; smelting; aluminum scrap.
|M.M.Sangov , S.M.Safarmamadov , К.S.Mabatradamzoda |
Complexation of copper (I) with thiocarbohydrazide
Using the potentiometric method, the complexation of Cu (I) with thiocarbohydrazide (TKZ) was studied at an ionic strength of 0.1 mol/l in the range of 288-328 K. It was shown that three complex particles are formed in the Cu (I)-TKZ-НО system. The general and stepwise stability constants of thiocarbohydrazide complexes of Cu (I) depending on temperature are determined. The thermodynamic functions of complex formation were calculated by the temperature coefficient method. It was shown that the stability of complexes of Cu (I) with thiocarbohydrazide is less than for silver (I).
Ключевые слова: thiocarbohydrazide; complexation thiosemicarbazide; copper (I); stability constant; thermodynamic functions.
|D.O.Davlatov , Sh.B.Nazarov , A.Giyosiddin , U.M.Mirsaidov |
Processiing of nefeline syenites by syntering with sodium sulfate
The results of study of processing of nefeline syenites of Turpi Deposit by sintering with sodium sulfate have been considered. The influence of various physicochemical factors on the process of opening of raw materials components at its sintering with sodium sulfate has been studied. The optimal parameters of sintering process have been determined. The flowsheet of ore processing has been proposed.
Ключевые слова: nefeline syennites; sodium sulfate; cake; processing.
|J.Kh.Juraev , A.S.Kurbonov , U.Kh.Usmonova , U.M.Mirsaidov |
Decomposition of the burnt borosilicate ore concentrate of Tajikistan Ak-Arkhar deposit with a mixture of ortophosphoric and nitric acids
The results of borosilicate ore concentrate decomposition studies of the Tajikistan Ak-Arkhar deposit by the acid method are presented. The optimal parameters for the decomposition process of the above mentioned raw materials with a mixture of phosphoric and nitric acids had been found.
Ключевые слова: borosilicate raw material concentrate; processing; phosphoric acid; nitric acid; decomposition; recovery.
|D.Kh.Mirzoev , Sh.O.Azamov , N.M.Jamolov , A.M.Kayumov , U.M.Mirsaidov |
Physical and chemical bases of sulfuric acid decomposition of green clays with preliminary sinteriing
with sodium hydroxide
The mechanism of the decomposition process of sinter by sulfuric acid was revealed during the sulfuric acid decomposition of green clays with preliminary sintering with sodium hydroxide and the following conditions for the decomposition of green clays of the Chashma-Sang deposit are recommended: sintering with NaOH at 800-850°С for 1 hour and subsequently aqueous-acid treatment at 98°С and 40% concentration of HSO. The recovery under these conditions was: AlO - 83%, FeO - 57%.
Ключевые слова: green clay; sulfuric acid decomposition; sintering; sodium hydroxide.
|J.N.Nizomov , R.R.Saidov , B.J.Fattoev |
Calculation of hardness diagrams on an elastic basis
by the method of focused deformations
The article presents the results of numerical simulation of the stiffness diaphragm problem on an elastic base with three bed coefficients using the method of concentrated deformations (MCD). The obtained results of calculating the stiffness diaphragm with holes according to the MCD are compared with data obtained by the finite element method (FEM).
Ключевые слова: a rigidity diaphragm; numerical modelling; a method of the concentrated deformations; the elastic basis; normal pressure; concentration of pressure.
|M.M.Mamadvafoev , D.A.Davlatshoev |
Special aspects of the apatite distribution and other accessoral and petrogenic minerals in the intrusive rocks of Kafandar ore field complexes (Eastern Hissar)
The article discusses the common factors of the quantitative distribution of apatite - the main mineral concentrator of phosphorus, as well as rock-forming quartz, orthoclase, albite, anorthite, biotite, hornblende and accessory corundum, wollastonite, calcite, magnetite and ilmenite in 11 types of inversion granitoid rocks (C2 - C3) and post-inversion-orogenic (P1) intrusive complexes of the Kafandar ore field. It is concluded that the distribution of apatite in granitoid rocks of intrusive complexes is controlled by the universal mechanism of the acid-base interaction of components in magmatic melts.
Ключевые слова: East Gissar; Kafandara ore field; granitoid and lamprophyric rocks of intrusive complexes; apatite distribution in rocks; connection of apatite with petrogenic and accessory minerals.
Petrochemical characterization volcano-plutonic
association of the Southern Hissar zone
The main goal of the work is a comprehensive regional geological, petrochemical, and mineralogical research necessary to determine the genesis of acidic volcanics and their relationships with related plutonites of the Lucchob complex, to identify the geodynamic conditions of formation and to elucidate the evolution of South Gissar volcanics.
Ключевые слова: daсites; trahidacites; dasitorhyolites; rhyolites; andesites; Southern Hissar zone.
|J.Niyazov , S.Mirzokhonova |
The impact of climate change on the runoff of the Varzob river basin for the period 1990-2016
According to long-term observations for the general period 1990-2016 the authors have been analyzed the causes of changes in the runoff of the Varzob River, the ongoing changes in climatic and hydrological parameters according to the weather station Anzob, Maykhura, Dushanbe and the Dagan gauging station of the Tajikhydromet network. Reducing the run-off of the Varzob River from 2007 to 2016 is associated with a decrease in snow cover reserves in the mountains and a decrease in the area of glaciation due to global warming and a decrease of the precipitations in winter period. There are presented the main characteristics of meteorological and hydrological parameters for the period 1990-2016.
Ключевые слова: river runoff; intra-annual change in river runoff; forecast of river water content for the flood period; Varzob river basin; the changing in meteorological parameters.
|Sh.I.Khojaev , M.В.Mahmadaliev |
Effects of the rice cultivation on the reclamation status of the residual salted gypsyferous soils
of the Karalang plato
The article presents the results of long-term studies on the effect of irrigation rice on the improvement of the land reclamation state of gypsyferous soils and the decrease the concentration of chloride in a meter of soil profile. It has been established that in the conditions of the Karalang plato, the desalination action of rice is preventive in nature and saline soils are regenerated for the next season.
Ключевые слова: rice; reclamation state; saline soils; gypsum-bearing soils; chlorine concentration; sulfates.
|I.I.Ikromov , M.I.Ikramova , Ilkhom I.Ikromov |
On the methodology for evaluating the effectiveness
of irrigation water use
An improved method is proposed for determining the efficiency of the irrigation system, the essence of which is to evaluate it by weighted average values that take into account the use of return water. It is defined as the ratio of product of scientifically grounded water supply volume per 1 ha of irrigated area (or net irrigation norm of crops) and net area irrigated field of the corresponding culture used plus the volume of return water to the actually received volume of water in the head water intake structure. The practical application of the proposed improved methodology allows us to assess the actual state of irrigation water use, according to which it is possible to provide the necessary measures to improve the efficiency of water and thus land resources use.
Ключевые слова: effective use of irrigation water; efficiency of the irrigation system; weighted average; return water; water availability of the field.
Ключевые слова: .