Katanov Khakass State University

Imeni Vladimira Il’icha Lenina, Russia

Katanov Khakass State University

Imeni Vladimira Il’icha Lenina, Russia
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Libelloides macaronius (Scopoli, 1763) is recorded trom steppes ot the Republic of Khakassia for the first time. © 1994, Far Eastern entomologist (Far East. entomol.).


Redel L.V.,Katanov Khakass State University | Gafner Y.Y.,Katanov Khakass State University | Gafner S.L.,Katanov Khakass State University | Zamulin I.S.,Katanov Khakass State University | Goloven'ko Z.V.,Katanov Khakass State University
Physics of Metals and Metallography | Year: 2017

Based on the computer simulation, the applicability of using individual nanoclusters of Pt, Pd, and particles of the Pd–Pt nanoalloy as unites of storage of data bits in nonvolatile memory devices, store capability of which is based on the principle of the phase change of the state of the carrier of information, has been estimated. To this end, the temperature and size limits of stability of different internal structures of nanoparticles in the course of the heating (to melting) and subsequent solidification (crystallization) with different rates of heat removal have been established. The results of the computer simulation of the nanoparticles of chemically pure platinum, palladium, and their alloy with different content of Pt atoms have been compared. It has been concluded that the best material for the memory cells the store capability of which is based on the occurrence of phase transitions is the nanoclusters of the Pd–Pt alloy with 10% platinum with a diameter D ≥ 3.5 nm. © 2017, Pleiades Publishing, Ltd.


Chepkasov I.V.,Katanov Khakass State University | Gafner Y.Y.,Katanov Khakass State University | Gafner S.L.,Katanov Khakass State University | Bardakhanov S.P.,RAS Institute of Theoretical and Applied Mechanics
Bulletin of Materials Science | Year: 2015

Technological applications of metallic clusters impose very strict requirements for particle size, shape, structure and defect density. Such geometrical characteristics of nanoparticles are mainly determined by the process of their growth. This work represents the basic mechanisms of cluster formation from the gas phase that has been studied on the example of copper. The process of Cu nanoclusters synthesis has been studied by the molecular- dynamics method based on tight-binding potentials. It has been shown that depending on the size and temperature of the initial nanoclusters the process of nanoparticle formation can pass through different basic scenarios. The general conditions of different types of particles formation have been defined and clear dependence of the cluster shape from collision temperature of initial conglomerates has been shown. The simulation results demonstrate a very good agreement with the available experimental data. Thus, it has been shown that depending on the specific application of the synthesized particles or in electronics, where particles of a small size with a spherical shape are required, or in catalytic reactions, where the main factor of effectiveness is the maximum surface area with the help of temperature of the system it is possible to get the realization of a certain frequency of this or that scenario of the shape formation of nanocrystalline particles. © Indian Academy of Sciences.


Gafner S.L.,Katanov Khakass State University | Gafner J.J.,Katanov Khakass State University | Bardakhanov S.P.,RAS Institute of Theoretical and Applied Mechanics | Lysenko V.I.,RAS Institute of Theoretical and Applied Mechanics
Journal of Computational and Theoretical Nanoscience | Year: 2012

The process of Ni nanoclusters synthesis from the gas phase had been studied by the molecular-dynamics method based on tight-binding potentials. The gas phase was produced after evaporation of melted nickel using high energy electron beam. Experimental procedure originated the nanoparticles of two fractions with average size 100 and 200 nanometers. Computer analysis of system evolution shows the splitting can occur due to consolidation of large enough primary clusters. The simulation shows two stages of system evolution. At the first stage the consolidation occurs for clusters belonging to the range of the largest values of size distribution in accordance with theory predictions. At the second stage the largest probability corresponds to consolidation of biggest particles. Finally it leads to bimodal size distribution which is not observed at usual theoretical analysis of condensation process. © 2012 American Scientific Publishers. All rights reserved.


Chepkasov I.V.,Katanov Khakass State University | Gafner Y.Y.,Katanov Khakass State University | Gafner S.L.,Katanov Khakass State University | Bardahanov S.P.,RAS Institute of Theoretical and Applied Mechanics
Physics of Metals and Metallography | Year: 2016

In order to determine the most efficient modes of copper-nanoparticle synthesis, a number of experiments on evaporation with the subsequent condensation of the initial material in the argon atmosphere have been carried out. In the course of the experiments, it has been discovered that intensified evaporation significantly increases the average size of the synthesized particles. However, the investigation of the change in the dimensional characteristics of the produced clusters depending on the intensity of the buffer-gas flow faced serious difficulties. The obtained results differ significantly from the earlier experiments on the synthesis of the transition-metal oxides. In order to solve this contradiction, the computer simulation of the condensation of copper atoms from the gas phase with three different cooling rates and two final temperatures T = 373 K and Т = 77 K has been performed. It has been discovered that the cooling rate of the gas mixture and the final temperature directly influence the quantity and size of the produced particles. Thus, at a tenfold lower cooling rate, the average number of particles increases 2.7 times at a final temperature of 77 K and by 3.1 times at T = 373 K. © 2016, Pleiades Publishing, Ltd.


Samsonov V.M.,Tver State University | Gafner Y.Y.,Katanov Khakass State University | Gafner S.L.,Katanov Khakass State University | Zamulin I.S.,Katanov Khakass State University
Eurasian Chemico-Technological Journal | Year: 2012

The heat capacity of nanoclusters was investigated using thermodynamics of surfaces, taking into account the surface enthalpy introduced by E. Guggenhein. It is shown that the cluster heat capacity Cp should be greater than the heat capacity Cp (b) of the corresponding bulk phase. However, the (Cp - Cp (b))/Cp (b) ratio should not exceed 50% up to very small clusters containing 100 atoms. Theoretical estimations agree with molecular dynamics results. So, experimental data on metallic nanoclusters and nanostructures demonstrating that Cp exceeds Cp (b)) in 2-5 times should be incorrect. © 2012 al-Farabi Kazakh National University.


Chepkasov I.V.,Katanov Khakass State University | Gafner Y.Y.,Katanov Khakass State University | Gafner S.L.,Katanov Khakass State University
Journal of Aerosol Science | Year: 2016

The gas-phase condensation of 85,000 Cu atoms is examined by molecular dynamics simulation with a tight-binding potential. A detailed study of the evolution of the system cooled at a constant rate from 1000. K to 77. K is presented. The results are used to identify four distinct stages of the evolution from a hot atomic gas to a few synthesized particles. The effect of the subsequent thermal treatment on the shape and structure of synthesized particles was studied by simulating their gradual heating in a range of 100-1200. K. It is concluded that short-term heating leads to significant ordering of the internal structure in 70% of agglomerated nanoparticles with the predominant formation of spherical shapes. In order to explain this result, the main mechanisms of cluster formation from the gas phase have been analyzed and it is found that the agglomeration temperature plays the main role in the formation of clusters with unified shape and structure. © 2015 Elsevier Ltd.


Khar'kov V.N.,Russian Academy of Medical Sciences | Khamina K.V.,Russian Academy of Medical Sciences | Medvedeva O.F.,Russian Academy of Medical Sciences | Shtygasheva O.V.,Katanov Khakass State University | Stepanov V.A.,Russian Academy of Medical Sciences
Molecular Biology | Year: 2011

The structure of Khakass gene pool has been investigated: Y-chromosome haplogroup compositions and frequencies were described in seven population samples of two basic subethnic groups, Sagai and Kachins, from three geographically separated regions of the Khakass Republic. Eight haplogroups were detected in the Khakass gene pool: C3, E, N*, N1b, N1c, R1a1a, and R1b1b1. The haplogroup spectra and the genetic diversity by haplogroups and YSTR haplotypes differed significantly between Sagai and Kachins. Kachins had a low level of gene diversity, whereas the diversity of Sagai was similar to that of other South-Siberian ethnic groups. Sagai samples from the Askizskii district were very similar to each other, and so were two Kachin samples from the Shirinskii district, while Sagai samples from the Tashtypskii district differed considerably from each other. The contribution of intergroup differences among ethnic groups was high, indicating significant genetic differentiation among native populations in Khakassia. The Khakass gene pool was strongly differentiated both by haplogroup frequencies and by YSTR haplotypes within the N1b haplogroup. The frequencies of YSTR haplotypes within the chromosome Y haplogroups N1b, N1c, and R1a1 were determined and their molecular phylogeny was investigated. Factor and cluster analysis, as well as AMOVA, suggest that the Khakass gene pool is structured by territory and subethnic groups. © 2011 Pleiades Publishing, Ltd.


Myakhar V.V.,Katanov Khakass State University | Spirin D.V.,Katanov Khakass State University | Udodov V.N.,Katanov Khakass State University
Physics of Metals and Metallography | Year: 2013

A model of the magnetization distribution in thin ferromagnetic films that are in the so-called supercritical state has been considered. The model makes it possible to take into account the real distribution of the magnetization more precisely in ferromagnetic films than open and closed models. The theoretical results have been compared to the experimental data. © 2013 Pleiades Publishing, Ltd.


Goloven'ko Zh.V.,Katanov Khakass State University | Gafner Yu.Ya.,Katanov Khakass State University | Gafner S.L.,Katanov Khakass State University | Redel' L.V.,Katanov Khakass State University
Physics of Metals and Metallography | Year: 2013

Limits of thermal stability of the original fcc phase in gold clusters up to 3.5 nm in diameter have been studied. The simulation carried out by the molecular-dynamics method using a modified TB-SMA tight-binding potential has shown that in small Au clusters under the effect of the temperature factor there occurs a transition from the original fcc phase to other structural modifications, including those with a pentagonal symmetry. As the size of gold nanoparticles increases, the polytypic-transition temperature shifts toward the melting temperature of the cluster. The results obtained are compared with the data for copper and nickel nanoparticles with similar sizes. It has been shown that, in the case of nickel and copper clusters, it is the transition from the fcc phase into structures with a pentagonal symmetry, which are not found in the bulk state, that is the governing factor; the gold clusters demonstrate a much more intricate behavior. © Pleiades Publishing, Ltd., 2013.

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