Imeni Vladimira Il'icha Lenina, Russia

Voronezh State Pedagogical University
Imeni Vladimira Il'icha Lenina, Russia
Time filter
Source Type

Granato A.V.,University of Illinois at Urbana - Champaign | Joncich D.M.,University of Illinois at Urbana - Champaign | Khonik V.A.,Voronezh State Pedagogical University
Applied Physics Letters | Year: 2010

An interpretation of a long-standing problem-the Lindemann melting rule-has been suggested within the framework of the interstitialcy theory. Melting is considered to be due to the rapid generation of thermodynamically equilibrium defects-dumbbell interstitials, which drastically decrease the shear modulus at the melting point. An analytical expression for the relationship between the thermal expansion coefficient and melting temperature coinciding with the Lindemann melting rule has been derived. The obtained results agree with available data on elemental substances. A correlation between the melting temperature and shear modulus has been discovered and explained within the framework of the same approach. © 2010 American Institute of Physics.

Mitrofanov Yu.P.,Voronezh State Pedagogical University | Makarov A.S.,Voronezh State Pedagogical University | Khonik V.A.,Voronezh State Pedagogical University | Granato A.V.,University of Illinois at Urbana - Champaign | And 2 more authors.
Applied Physics Letters | Year: 2012

Within the framework of the interstitialcy theory, we derived a simple and testable expression for the heat flow (enthalpy relaxation rate) occurring upon warming of glass at a constant rate. Formally, this heat flow is mostly determined by the shear moduli of glass and parent crystal. The underlying physical reason is relaxation of an intrinsic interstitialcy-like defect system. An extensive check of the derived heat flow law for temperatures near the glass transition showed good agreement with the experiment specially performed on two Pd-based metallic glasses. © 2012 American Institute of Physics.

Tsyplakov A.N.,Voronezh State Pedagogical University | Mitrofanov Y.P.,Voronezh State Pedagogical University | Khonik V.A.,Voronezh State Pedagogical University | Kobelev N.P.,RAS Institute of Solid State Physics | Kaloyan A.A.,RAS Research Center Kurchatov Institute
Journal of Alloys and Compounds | Year: 2015

We measured the heat flow, shear modulus and density changes occurring upon heating of bulk glassy Pd41.25 Cu41.25 P17.5, which polymorphically crystallizes into tetragonal Pd2 Cu2P with simultaneous decrease of the density. It was found that the heat release (well below the glass transition temperature Tg) and heat absorption (near and above Tg) are uniquely linked to the relaxation of the shear modulus through the relaxation change of the concentration of internal "defects" frozen-in upon glass production. The two models suitable for a quantitative description of this interrelationship are discussed in detail. The obtained results clearly demonstrate an intrinsic connection of the shear moduli of glass and maternal crystal. © 2014 Elsevier B.V. All rights reserved.

Khonik V.A.,Voronezh State Pedagogical University | Kobelev N.P.,RAS Institute of Solid State Physics
Journal of Applied Physics | Year: 2014

It has been argued that the densification observed upon structural relaxation of metallic glasses can be explained not by the "free volume annihilation," as it is custom to consider, but by the annealing of interstitialcy-like "defects" frozen-in upon glass production. A simple expression for the enthalpy release due to relaxation of defect-induced dilatational energy has been proposed. The expression is shown to be in agreement with recent detailed experimental data on the heat release occurring upon structural relaxation of Au-based metallic glass [J. Bünz and G. Wilde, J. Appl. Phys. 114, 223503 (2013)]. © 2014 AIP Publishing LLC.

Makarov A.S.,Voronezh State Pedagogical University | Khonik V.A.,Voronezh State Pedagogical University | Wilde G.,University of Munster | Mitrofanov Yu.P.,University of Munster | And 2 more authors.
Intermetallics | Year: 2014

Calorimetric and shear modulus measurements on bulk glassy Pd 40Ni40P20 are performed. The obtained data is used for the calculation of structural relaxation-induced heat flow within the framework of the Interstitialcy theory. A good correspondence between the calculated and experimental heat release and absorption both below and above Tg is found. It is concluded that a description based on the population of "defect" states that are similar to dumbbell interstitials is capable to correctly describe the observed heat flow. © 2013 Elsevier Ltd. All rights reserved.

Timofeev A.N.,Voronezh State Pedagogical University
Russian Journal of Ecology | Year: 2016

The species composition of Odonata facultatively associated with forest ecosystems at the adult stage have been studied in the forest–steppe of Central Chernozem region. Factors facilitating the entry of adult dragonflies deep into forested areas, specific features of their behavior in the forest, and the role of human activities in the spread of these insects in forest ecosystems have been elucidated. © 2016, Pleiades Publishing, Ltd.

Kornev S.V.,Voronezh State Pedagogical University
Bulletin of the South Ural State University, Series: Mathematical Modelling, Programming and Computer Software | Year: 2016

As it is known, differential inclusions are very useful mathematical tools to describe nonlinear control systems with feedback, automatic control systems, discontinuous systems, impulse response and other objects of modern engineering, mechanics, physics. In the present paper the new method to solving the problem of periodic oscillations of controlled systems described by a differential inclusion with a causal multioperator is introduced. Firstly differential equations with causal operator, or Volterra type equations where considered by L. Tonelli and A.N. Tikhonov. A.N. Tikhonov used them as the model in study of some thermal conductivity problems, in particular the problem of body coding when there is radiation from its surface. At first we consider the case when the multioperator is closed and convex-valued. Then the case of a non-convex-valued and lower semicontinuous right-hand part is considered. As the main research tool of the problem in both cases a modified method of the classical guiding function is applied. Namely, the method of nonsmooth integral guiding function is considered. Application of topological degree theory and this method allows to establish the solvability of periodic problem in each of the cases.

Konchakov R.A.,Voronezh State Pedagogical University | Khonik V.A.,Voronezh State Pedagogical University
Physics of the Solid State | Year: 2014

It has been shown by the molecular dynamics method that the introduction of interstitials in the dumbbell configuration into the copper crystal leads to a significantly stronger shear modulus reduction than the vacancy introduction. Specific low-frequency modes appear in the spectrum of vibrational states of "defect" atoms. The vacancy formation enthalpy weakly depends on their concentration, and the interstitial dumbbell formation enthalpy at high concentrations can decrease by a factor of 8. In this case, the radial distribution function takes the form characteristic of noncrystalline materials. The results obtained confirm the interstitial theory of the condensed state. © 2014 Pleiades Publishing, Ltd.

A review of the new approach to the understanding of the structural relaxation of metallic glasses based on the interstitialcy theory has been presented. The key hypothesis of this theory proposed by Granato consists of the statement that the thermodynamic properties of crystalline, liquid and glassy states are closely related to the interstitial defects in the dumbbell (split) configuration, called also interstitialcies. It has been argued that structural relaxation of metallic glasses takes place through a change of the concentration of interstitialcy defects frozen-in from the melt upon glass production. Because of a strong interstitialcy-induced shear softening, the defect concentration can be precisely monitored by measurements of the unrelaxed shear modulus. Depending on the relation between the current interstitialcy concentration c and interstitialcy concentration in the metastable equilibrium, different types of structural relaxation (decreasing or increasing c) can be observed. It has been shown that this approach leads to a correct description of the relaxation kinetics at different testing conditions, heat effects occurring upon annealing, shear softening and a number of other structural relaxation-induced phenomena in metallic glasses. An intrinsic relation of these phenomena with the anharmonicity of the interatomic interaction has been outlined. A generalized form of the interstitialcy approach has been reviewed. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Shakurova M.V.,Voronezh State Pedagogical University
International Journal of Environmental and Science Education | Year: 2016

The article addresses the problem of defining and attributing pedagogic essence to the mechanisms of personality identity development. It is based on the general mechanism of social interaction. Its structure contains, on the one hand, pedagogic interaction, including the forms of pedagogic assistance and pedagogic support; on the other hand, it also contains such components as impulse, perception, manipulation and conclusion (according to G.H. Mead). As a result, with regard to the pedagogic context with specified scientific-methodic supply, we explore local mechanisms of development (stimulating, teaching) of reflection and reflective behavior; acceptance of the Other’s role; learning the choice and facilitating a motivated reasonable choice. We review the developmental potential of pedagogics of game, theatrical pedagogics, communicative attack technique, reflective teaching and mentoring, pedagogic support of empathy development, etc., for personality identity development. © 2016 Shakurova.

Loading Voronezh State Pedagogical University collaborators
Loading Voronezh State Pedagogical University collaborators