Pub Date : 2021-09-01DOI: 10.26577/rcph.2021.v78.i3.09
A. Fedosimova, I. A. Lebedev, E. Dmitriyeva, S. Ibraimova, E. A. Bondar, P. Krassovitskiy
To search for signals of the phase transition of matter from the hadronic state to the quarkgluon plasma, interactions with extreme characteristics are studied. The study of the dependence of the average multiplicity on the projectile energy for sulfur and silicon nuclei with energies of 3.7 AGeV, 14 AGeV, and 200 AGeV has been carried out. Experimental data on inelastic interactions with the nuclei of the NIKFI BR2 emulsion obtained at the SPS at CERN and at the Synchrophasotron at JINR. To take into account fluctuations in the initial conditions of the nucleusnucleus interaction, the events were divided into central and peripheral ones. A comparative analysis of the average multiplicity with heavy and light nuclei of the photographic emulsion is presented. The multiplicity increase factor has an almost linear increase in energy (on the logarithmic axis) for all events, except for the central interactions of sulfur nuclei with heavy emulsion nuclei at 200 AGeV. These events are explosive events, which give a flux of secondary particles in a narrow range of average pseudorapidity and significantly shifted towards low values . The analysis of events of complete destruction of the projectile nucleus is presented. Such events are considered as events in which the most favorable conditions are created for the formation of a quarkgluon plasma.
{"title":"Features of the distribution of events by the multiple of secondary particles depending on the energy of collision and the assymetricity of collising relativistic nuclei","authors":"A. Fedosimova, I. A. Lebedev, E. Dmitriyeva, S. Ibraimova, E. A. Bondar, P. Krassovitskiy","doi":"10.26577/rcph.2021.v78.i3.09","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.09","url":null,"abstract":"To search for signals of the phase transition of matter from the hadronic state to the quarkgluon plasma, interactions with extreme characteristics are studied. The study of the dependence of the average multiplicity on the projectile energy for sulfur and silicon nuclei with energies of 3.7 AGeV, 14 AGeV, and 200 AGeV has been carried out. Experimental data on inelastic interactions with the nuclei of the NIKFI BR2 emulsion obtained at the SPS at CERN and at the Synchrophasotron at JINR. To take into account fluctuations in the initial conditions of the nucleusnucleus interaction, the events were divided into central and peripheral ones. A comparative analysis of the average multiplicity with heavy and light nuclei of the photographic emulsion is presented. The multiplicity increase factor has an almost linear increase in energy (on the logarithmic axis) for all events, except for the central interactions of sulfur nuclei with heavy emulsion nuclei at 200 AGeV. These events are explosive events, which give a flux of secondary particles in a narrow range of average pseudorapidity and significantly shifted towards low values . The analysis of events of complete destruction of the projectile nucleus is presented. Such events are considered as events in which the most favorable conditions are created for the formation of a quarkgluon plasma.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46622352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.26577/rcph.2021.v78.i3.08
K. Kombaev, D.S. Elamanov, A. Kassenova, D.S. Kamzin, G.M. Toktarbaeva
An alternative technology of strengthening by electrolyticplasma modification of lowcarbon alloy steel for the wedge columns binding for stop valves has been developed. The processing of steel 20X samples was carried out on an experimental installation, the optimal processing modes were determined experimentally. Simulation of the treated surface makes it possible to assume that during the electrolyticplasma heating of parts, along with quenching, chemical modification of the metal surface layers occurs. The volttemperature characteristic with the superposition of real time on the proposed processing clearly shows a significant reduction in the time for hardening, relative to traditional hardening methods of similar steel. Also, energy consumption and, accordingly, the cost of the part and the product as a whole are significantly reduced. Electrolyteplasma modification promotes the transformation of coarsegrained pearliteferrite microstructure into quenched martensite. An increase in hardness relative to the initial state indicates an increase in physical and mechanical properties after electrolyteplasma treatment. The advantage of the method of electrolyticplasma treatment consists in low energy consumption at high quenching rates, the possibility of local surface treatment; there are prerequisites for creating a semiindustrial installation for an alternative electrolyteplasma hardening.
{"title":"Structural-phase state of the surface layer of low-carbon steel after electrolytic-plasma modification","authors":"K. Kombaev, D.S. Elamanov, A. Kassenova, D.S. Kamzin, G.M. Toktarbaeva","doi":"10.26577/rcph.2021.v78.i3.08","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.08","url":null,"abstract":"An alternative technology of strengthening by electrolyticplasma modification of lowcarbon alloy steel for the wedge columns binding for stop valves has been developed. The processing of steel 20X samples was carried out on an experimental installation, the optimal processing modes were determined experimentally. Simulation of the treated surface makes it possible to assume that during the electrolyticplasma heating of parts, along with quenching, chemical modification of the metal surface layers occurs. The volttemperature characteristic with the superposition of real time on the proposed processing clearly shows a significant reduction in the time for hardening, relative to traditional hardening methods of similar steel. Also, energy consumption and, accordingly, the cost of the part and the product as a whole are significantly reduced. Electrolyteplasma modification promotes the transformation of coarsegrained pearliteferrite microstructure into quenched martensite. An increase in hardness relative to the initial state indicates an increase in physical and mechanical properties after electrolyteplasma treatment. The advantage of the method of electrolyticplasma treatment consists in low energy consumption at high quenching rates, the possibility of local surface treatment; there are prerequisites for creating a semiindustrial installation for an alternative electrolyteplasma hardening.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48213658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.26577/rcph.2021.v78.i3.01
Z. Tyulemissov, A. Issadykov, A. Bekbaev, D. Aznabaev, K. Nurlan
We calculated a subclass of four nonleptonic two-body weak decays of the double charm baryon ground states Ξcc++. Nonleptonic decays can be dividedinto two group: factorizable and nonfactorizable decays. The first one can be easily calculated from first principles. Therefore, its good example understands all pros and cons of a model. We focused on a weak two-body nonleptonic decay consists only fromthe factorizing contribution precluding a contamination from W-exchange. We use the covariant confined quark model previously developed by us to calculate the various helicity amplitudes which describe the dynamics of the transition induced by the Cabibbo-favored effective currents. Achievement of CCQM is that only size parameter Λvarying can describe all tree diagrams of nonleptonic decay. We then proceed to calculate the rates of the decay. The rates, branching ratios and helicity amplitude were calculated using dimensionless invariant form factors. Also, we calculated leptonic constant for scalar and vector mesons which has good agreement with experimental data. There isn’t any experimental data about the decay so we waiting for new experimental observation in the heavy baryon sector.
{"title":"Calculation of doubly heavy baryons decay","authors":"Z. Tyulemissov, A. Issadykov, A. Bekbaev, D. Aznabaev, K. Nurlan","doi":"10.26577/rcph.2021.v78.i3.01","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.01","url":null,"abstract":"We calculated a subclass of four nonleptonic two-body weak decays of the double charm baryon ground states Ξcc++. Nonleptonic decays can be dividedinto two group: factorizable and nonfactorizable decays. The first one can be easily calculated from first principles. Therefore, its good example understands all pros and cons of a model. We focused on a weak two-body nonleptonic decay consists only fromthe factorizing contribution precluding a contamination from W-exchange. We use the covariant confined quark model previously developed by us to calculate the various helicity amplitudes which describe the dynamics of the transition induced by the Cabibbo-favored effective currents. Achievement of CCQM is that only size parameter Λvarying can describe all tree diagrams of nonleptonic decay. We then proceed to calculate the rates of the decay. The rates, branching ratios and helicity amplitude were calculated using dimensionless invariant form factors. Also, we calculated leptonic constant for scalar and vector mesons which has good agreement with experimental data. There isn’t any experimental data about the decay so we waiting for new experimental observation in the heavy baryon sector.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45410663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.26577/rcph.2021.v78.i3.10
N. Meirambekuly, B. Karibayev, A. Temirbayev, A. Imanbayeva
The CubeSat concept has become very popular with both university groups and researchers, space agencies, governments and companies. CubeSat offers a fast and affordable way for a wide range of stakeholders to be active in space. Due to the high degree of modularity and widespread use of offtheshelf commercial subsystems, CubeSat projects can be prepared for flight much faster than using traditional satellite schedules usually within one to two years. In this paper, we have considered a model of an S and X band patch antenna for CubeSat nanosatellites in the field of Earth remote sensing (ERS). The antenna dimensions were determined and designed according to the dimensions of the small spacecraft. The shape of the emitting part was formed using a geometric fractal with an anisotropic structure. Using the CST Microwave Studio software package, the electrodynamic, frequency characteristics and directional properties of the antenna were determined. The results of computer simulations demonstrate that the developed antenna concept has a multiband property and meets all the parameters that are necessary for receiving and transmitting data in the S and X bands. It was also found that the anisotropic fractal structure allows the antenna to have several operating frequencies.
{"title":"S and X band patch antenna for CubeSat nanosatellites","authors":"N. Meirambekuly, B. Karibayev, A. Temirbayev, A. Imanbayeva","doi":"10.26577/rcph.2021.v78.i3.10","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.10","url":null,"abstract":"The CubeSat concept has become very popular with both university groups and researchers, space agencies, governments and companies. CubeSat offers a fast and affordable way for a wide range of stakeholders to be active in space. Due to the high degree of modularity and widespread use of offtheshelf commercial subsystems, CubeSat projects can be prepared for flight much faster than using traditional satellite schedules usually within one to two years. In this paper, we have considered a model of an S and X band patch antenna for CubeSat nanosatellites in the field of Earth remote sensing (ERS). The antenna dimensions were determined and designed according to the dimensions of the small spacecraft. The shape of the emitting part was formed using a geometric fractal with an anisotropic structure. Using the CST Microwave Studio software package, the electrodynamic, frequency characteristics and directional properties of the antenna were determined. The results of computer simulations demonstrate that the developed antenna concept has a multiband property and meets all the parameters that are necessary for receiving and transmitting data in the S and X bands. It was also found that the anisotropic fractal structure allows the antenna to have several operating frequencies.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47359244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.26577/rcph.2021.v78.i3.04
A. Kovanov, D. Zhignovskaya, V. Tsvetkov, V. Pronin
The paper deals with some aspects of mathematical modeling of a scroll compressor. Various approaches to modeling the working processes of machines of the volumetric compression principle, their applied value and priority of use are presented. An analytical review of the methods for calculating the leakage of a compressed medium, applied to a scroll compressor, taking into account the classification of slots, is carried out. Conclusions are made about the need to clarify the assumptions and improve this technique by taking into account the fact of the mobility of the walls of the gap, depending on the share of the influence of various factors on the leakage of the compressed medium. And also about the influence of this fact on the accuracy of calculations and the optimal choice of the operating mode of the compressor. Examples are given in which taking this condition into account in the transformed systems of equations will improve the accuracy in applied calculations of the working processes of spiral machines, when designing new samples.
{"title":"Scroll compressor. Analysis of calculation methods","authors":"A. Kovanov, D. Zhignovskaya, V. Tsvetkov, V. Pronin","doi":"10.26577/rcph.2021.v78.i3.04","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.04","url":null,"abstract":"The paper deals with some aspects of mathematical modeling of a scroll compressor. Various approaches to modeling the working processes of machines of the volumetric compression principle, their applied value and priority of use are presented. An analytical review of the methods for calculating the leakage of a compressed medium, applied to a scroll compressor, taking into account the classification of slots, is carried out. Conclusions are made about the need to clarify the assumptions and improve this technique by taking into account the fact of the mobility of the walls of the gap, depending on the share of the influence of various factors on the leakage of the compressed medium. And also about the influence of this fact on the accuracy of calculations and the optimal choice of the operating mode of the compressor. Examples are given in which taking this condition into account in the transformed systems of equations will improve the accuracy in applied calculations of the working processes of spiral machines, when designing new samples.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47374333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.26577/rcph.2021.v78.i3.03
A. Aldiyarov, D. Sokolov, A. Tychengulova, D. Yerezhep
It is known that by changing the concentration in an inert medium, it is possible to form clusters of various sizes of any substance by condensing them on a cold substrate from the gas phase. Traditionally, such systems are presented by molecular cryocrystals. This paper demonstrates the results of IR spectrometric studies of cryovacuum condensates of ethanol mixture with nitrogen. The main task of this study is to explain the complex, most often, ambiguous behavior of thin films of ethanol cryovacuum condensates in the process of its cocondensation with nitrogen. For this purpose, vibrational spectroscopy of cryodeposited thin films of “ethanol in nitrogen” mixtures in various concentration ratios was performed. The objects of research are thin films of cryocondensates of ethanol mixture with inert gas (N2). The samples were condensed at the temperature T = 16 K. The pressure of the gas phase of the mixture during cryocondensation was kept at P = 105 Torr. The range of ethanol concentrations in the mixtures varied from 3% to 90%. The spectral range of measurements was considered in 400-4200 1/cm. It is assumed that the change in the concentration of ethanol in the mixture leads to the formation of various cluster compositions of ethanol molecules dissolved in an inert medium.
{"title":"Vibrational spectroscopy of thin film condensates of ethanol mixture with inert gase","authors":"A. Aldiyarov, D. Sokolov, A. Tychengulova, D. Yerezhep","doi":"10.26577/rcph.2021.v78.i3.03","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.03","url":null,"abstract":"It is known that by changing the concentration in an inert medium, it is possible to form clusters of various sizes of any substance by condensing them on a cold substrate from the gas phase. Traditionally, such systems are presented by molecular cryocrystals. This paper demonstrates the results of IR spectrometric studies of cryovacuum condensates of ethanol mixture with nitrogen. The main task of this study is to explain the complex, most often, ambiguous behavior of thin films of ethanol cryovacuum condensates in the process of its cocondensation with nitrogen. For this purpose, vibrational spectroscopy of cryodeposited thin films of “ethanol in nitrogen” mixtures in various concentration ratios was performed. The objects of research are thin films of cryocondensates of ethanol mixture with inert gas (N2). The samples were condensed at the temperature T = 16 K. The pressure of the gas phase of the mixture during cryocondensation was kept at P = 105 Torr. The range of ethanol concentrations in the mixtures varied from 3% to 90%. The spectral range of measurements was considered in 400-4200 1/cm. It is assumed that the change in the concentration of ethanol in the mixture leads to the formation of various cluster compositions of ethanol molecules dissolved in an inert medium.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47575682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.26577/rcph.2021.v78.i3.05
K. Egizbek, K. Kadyrzhanov
The aim of this work is systematic study of the thermal annealing effect on the preparation of nanostructured composites NdFeO3/Fe2O3 with a spinel type structure. The interest in these nanocomposites is due to the enormous potential of their application as a basis for magnetic devices, catalysts, and magnetic carriers for targeted drug delivery. As a synthesis method, twostage synthesis was used, which includes mechanochemical grinding of nanopowders Fe2O3 and Nd2O3 in a planetary mill, followed by thermal annealing of the resulting mixture in a wide temperature range: 6001000°C. During the studies carried out, it was found that in the initial state the obtained nanocomposites are a mixture of a solid solution of interstitial and substitutional Fe2O3 and Nd2O3. At an annealing temperature of 600°C, the onset of the formation of the NdFeO3 phase is observed, which at a temperature of 1000°C is fully formed and dominates in the composite structure (content more than 85%). It was also found that during thermal sintering, the processes of phase transformations of the Fe2O3Nd2O3→NdFeO3/Fe2O3 type are accompanied by an increase in the particle size by a factor of 1.52
{"title":"STUDY OF PHASE FORMATION IN FE2O3-ND2O3→NDFEO3/FE2O3 NANOCOMPOSITES AS A RESULT OF THERMAL ANNEALING","authors":"K. Egizbek, K. Kadyrzhanov","doi":"10.26577/rcph.2021.v78.i3.05","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.05","url":null,"abstract":"The aim of this work is systematic study of the thermal annealing effect on the preparation of nanostructured composites NdFeO3/Fe2O3 with a spinel type structure. The interest in these nanocomposites is due to the enormous potential of their application as a basis for magnetic devices, catalysts, and magnetic carriers for targeted drug delivery. As a synthesis method, twostage synthesis was used, which includes mechanochemical grinding of nanopowders Fe2O3 and Nd2O3 in a planetary mill, followed by thermal annealing of the resulting mixture in a wide temperature range: 6001000°C. During the studies carried out, it was found that in the initial state the obtained nanocomposites are a mixture of a solid solution of interstitial and substitutional Fe2O3 and Nd2O3. At an annealing temperature of 600°C, the onset of the formation of the NdFeO3 phase is observed, which at a temperature of 1000°C is fully formed and dominates in the composite structure (content more than 85%). It was also found that during thermal sintering, the processes of phase transformations of the Fe2O3Nd2O3→NdFeO3/Fe2O3 type are accompanied by an increase in the particle size by a factor of 1.52","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44192971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.26577/rcph.2021.v78.i3.02
M. K. Issanova, S. Kodanova, N. Bastykova, A. Kenzhebekova
In this paper, the processes of electron-ion scattering in the plasma of inertial confinement fusion in a magnetic field were studied. The proposed model for studying the processes of scattering between charged particles is based on solving the equation of motion in a central field taking into account the external magnetic field, as well as the Coulomb logarithm, which is determined using the scattering angle in a pair collision. Collisions between an electron and an ion that interact via the Yukawa potential were investigated. Also, the Coulomb logarithm in a dense plasma in a magnetic field was calculated. The effect of taking into account the magnetic field on the scattering angles, the scattering cross-section and the Coulomb logarithm are studied. From the results obtained, it is established that taking into account the magnetic field led to a non-monotonic change in the scattering angle and a decrease in the scattering cross-section for weak particle interactions. It is also revealed that for large values of the interaction parameterβ, the magnetic field does not affect the value of the Coulomb logarithm. Thus, the obtained results allow us to study the effect of taking into account the magnetic field on the processes of electron scattering on an ion in the approximation of pair collisions in an external constant magnetic field in a dense plasma.
{"title":"Investigation of the scattering of electrons by ions in the plasma of inertial confinement fusion in a magnetic field","authors":"M. K. Issanova, S. Kodanova, N. Bastykova, A. Kenzhebekova","doi":"10.26577/rcph.2021.v78.i3.02","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.02","url":null,"abstract":"In this paper, the processes of electron-ion scattering in the plasma of inertial confinement fusion in a magnetic field were studied. The proposed model for studying the processes of scattering between charged particles is based on solving the equation of motion in a central field taking into account the external magnetic field, as well as the Coulomb logarithm, which is determined using the scattering angle in a pair collision. Collisions between an electron and an ion that interact via the Yukawa potential were investigated. Also, the Coulomb logarithm in a dense plasma in a magnetic field was calculated. The effect of taking into account the magnetic field on the scattering angles, the scattering cross-section and the Coulomb logarithm are studied. From the results obtained, it is established that taking into account the magnetic field led to a non-monotonic change in the scattering angle and a decrease in the scattering cross-section for weak particle interactions. It is also revealed that for large values of the interaction parameterβ, the magnetic field does not affect the value of the Coulomb logarithm. Thus, the obtained results allow us to study the effect of taking into account the magnetic field on the processes of electron scattering on an ion in the approximation of pair collisions in an external constant magnetic field in a dense plasma.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47400525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-26DOI: 10.26577/rcph.2021.v78.i3.06
A.M. Assilbekova, A.A. Aldongarov, I.S. Irgibaeva
Quantum dots, such as cadmium sulfide (CdS), are semiconductor nanocrystals that possess unique optical properties, including widerange excitation, sizetunable narrow emission spectra and high photostability. The size and composition of quantum dots can be varied to obtain the desired emission properties and make them suitable for various optical and biomedical applications. In this article, the effect of selfaggregation on the electronic absorption spectra and on the dipole moment in CdS nanoparticles is considered using computer modeling methods based on the density functional tightbinding (DFTB). The object of the study is four CdS structures and two models of an aggregated dimer for each cluster. The construction of dimers of cadmium sulfide clusters showed that a higher level of passivation can be achieved in comparison with the initial monomers. In this case, the construction of dimers should occur along the direction of the dipole moment of the monomer in order to minimize it. Therefore, it can be assumed that the dipole moment plays a key role in the formation of trap states in nanosized clusters of cadmium sulfide, and the problem of passivation is reduced to minimizing the dipole moment.
{"title":"АССМОТРЕНИЕ ВЛИЯНИЯ САМОАГРЕГИРОВАНИЯ В НАНОРАЗМЕРНЫХ КЛАСТЕРАХ CDS","authors":"A.M. Assilbekova, A.A. Aldongarov, I.S. Irgibaeva","doi":"10.26577/rcph.2021.v78.i3.06","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.06","url":null,"abstract":"Quantum dots, such as cadmium sulfide (CdS), are semiconductor nanocrystals that possess unique optical properties, including widerange excitation, sizetunable narrow emission spectra and high photostability. The size and composition of quantum dots can be varied to obtain the desired emission properties and make them suitable for various optical and biomedical applications. In this article, the effect of selfaggregation on the electronic absorption spectra and on the dipole moment in CdS nanoparticles is considered using computer modeling methods based on the density functional tightbinding (DFTB). The object of the study is four CdS structures and two models of an aggregated dimer for each cluster. The construction of dimers of cadmium sulfide clusters showed that a higher level of passivation can be achieved in comparison with the initial monomers. In this case, the construction of dimers should occur along the direction of the dipole moment of the monomer in order to minimize it. Therefore, it can be assumed that the dipole moment plays a key role in the formation of trap states in nanosized clusters of cadmium sulfide, and the problem of passivation is reduced to minimizing the dipole moment.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41689115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-15DOI: 10.26577/rcph.2021.v78.i3.07
B. Useinov, A. Solodovnik, S. Zhumabayeva
Based on the physical analysis of the processes occurring in pulsed plasma accelerators, the possibility of their use for the creation and study of a plasma focus is justified. In particular, the influence of inductance on the parameters of the plasma focus in kilojoulerange «Plasma focus» (PF) installations created on the basis of a pulsed coaxial accelerator is studied. An equivalent installation scheme is proposed and justified, based on the analysis of which the influence of the inductance of the circuit and the capacitance of the capacitor bank on the value of the maximum current and neutron output is analyzed, without taking into account the parameters of the spark gap and the conducting wires. Based on the theoretical estimate of the inductance of the installation, its most probable value is calculated. . It turned out that in the installations of the considered energy range, the inductance is approximately 7.5•107 Gn and depends on the capacitance of the capacitor bank. On the contrary, in installations with megajoule energy, the inductance does not depend on the number and capacity of capacitors, so that an increase in the latter does not affect the increase in current strength. Experimental and theoretical dependences of the discharge current on the applied voltage at different capacitances of the capacitor bank are obtained. A comparative analysis of theoretical and experimental current waveforms is presented. The greatest coincidence of theoretical and experimental results was found for the duration of the discharge pulse T = 30 microseconds.
{"title":"Effect of inductance on the parameters of the plasma focus in a pulsed coaxial accelerator","authors":"B. Useinov, A. Solodovnik, S. Zhumabayeva","doi":"10.26577/rcph.2021.v78.i3.07","DOIUrl":"https://doi.org/10.26577/rcph.2021.v78.i3.07","url":null,"abstract":"Based on the physical analysis of the processes occurring in pulsed plasma accelerators, the possibility of their use for the creation and study of a plasma focus is justified. In particular, the influence of inductance on the parameters of the plasma focus in kilojoulerange «Plasma focus» (PF) installations created on the basis of a pulsed coaxial accelerator is studied. An equivalent installation scheme is proposed and justified, based on the analysis of which the influence of the inductance of the circuit and the capacitance of the capacitor bank on the value of the maximum current and neutron output is analyzed, without taking into account the parameters of the spark gap and the conducting wires. Based on the theoretical estimate of the inductance of the installation, its most probable value is calculated. . It turned out that in the installations of the considered energy range, the inductance is approximately 7.5•107 Gn and depends on the capacitance of the capacitor bank. On the contrary, in installations with megajoule energy, the inductance does not depend on the number and capacity of capacitors, so that an increase in the latter does not affect the increase in current strength. Experimental and theoretical dependences of the discharge current on the applied voltage at different capacitances of the capacitor bank are obtained. A comparative analysis of theoretical and experimental current waveforms is presented. The greatest coincidence of theoretical and experimental results was found for the duration of the discharge pulse T = 30 microseconds.","PeriodicalId":29678,"journal":{"name":"Recent Contributions to Physics","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42107383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：