Novosibirsk State Technical University , until 1992 the Novosibirsk Electrotechnical Institute , is one of the major research and educational centers of Russia as well as one of the top technical universities located in Novosibirsk, Russia. Wikipedia.
Chernyshev A.P.,Novosibirsk State Technical University
European Physical Journal B | Year: 2011
The Mie-Grüneisen equation is adapted for the description of the thermodynamic properties of nano-objects. It is shown that the Grüneisen parameter Γ depends on the ratio of the number of surface atoms to the number of interior atoms of the nano-objects. This ratio is determined by the characteristic size of nano-object and its form. It increases with decrease of the characteristic size. Reduction of the characteristic size of nano-objects that have a free surface, leads to a change in the Grüneisen parameter. If the nano-object is embedded in a matrix and has with it the coherent boundary, at the decrease of the nano-object size occurs either an increase or decrease of Γ. Compression or stretching of nano-objects may bring about a change of the ratio between numbers of the interior and surface atoms caused by changing the form of nano-objects. The change of the Grüneisen parameter at the characteristic size decreasing of a nano-object is treated as the change of a degree of the anharmonicity of lattice thermal vibrations. It is established that an appreciable change of Γ occurs if the characteristic radius of a nano-object is less than 5 nm. © 2011 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.
Kibis O.V.,Novosibirsk State Technical University
Physical Review B - Condensed Matter and Materials Physics | Year: 2012
It is demonstrated that the strong coupling of an electron gas to photons in systems with broken time-reversal symmetry results in bound electron-photon states which cannot be backscattered elastically. As a consequence, the electron gas can flow without dissipation. This quantum macroscopic phenomenon leads to the unconventional superconductivity which is analyzed theoretically for a two-dimensional electron system in a semiconductor quantum well exposed to an in-plane magnetic field. © 2012 American Physical Society.
Levyakov S.V.,Novosibirsk State Technical University
Acta Mechanica | Year: 2013
The problem of nonlinear thermal bending of a pinned slender beam fabricated of functionally graded material is considered. Based on the concept of physically neutral surface, the problem is reduced to a system of two coupled transcendental equations in terms of Legendre's elliptic integrals. Solutions of these equations are presented in graphical and tabular form. Specific features of the nonlinear response of the functionally graded beam under thermal loading are discussed. © 2013 Springer-Verlag Wien.
Kibis O.V.,Novosibirsk State Technical University
Physical Review B - Condensed Matter and Materials Physics | Year: 2010
Exact stationary solutions of the electron-photon Dirac equation are obtained to describe the strong interaction between massless Dirac fermions in graphene and circularly polarized photons. It follows from them that this interaction forms bound electron-photon states which should be considered as a kind of charged quasiparticles. The energy spectrum of the quasiparticles is of dielectric type and characterized by an energy gap between the valence and conductivity bands. Therefore the electron-photon interaction results in metal-insulator transition in graphene. The stationary energy gap, induced by photons, and concomitant effects can be observed for graphene exposed to a laser-generated circularly polarized electromagnetic wave. © 2010 The American Physical Society.
Chirkunov Y.A.,Novosibirsk State Technical University
Journal of Mathematical Physics | Year: 2015
We study the five-parameter model, describing the process of nonlinear diffusion in an inhomogeneous medium in the presence of absorption, for which the differential equation of the model admits a continuous Lie group of transformations, acting on the set of its solutions. We found six submodels of the original model of nonlinear diffusion, with different symmetry properties. Of these six submodels, the five submodels with transient absorption, for which the absorption coefficient depends on time according to a power law, represent the greatest interest with a mathematical point of view and with the point of view of physical applications. For each of these nonlinear submodels, we obtained formulas for producing new solutions that contain arbitrary constants, and we found all invariant submodels. All essentially distinct invariant solutions describing these invariant submodels are found in an explicit form or are reduced to finding the solution of nonlinear integral equations. The presence of the arbitrary constants in the integral equations that determine these solutions provide new opportunities for analytical and numerical study of boundary value problems for the received submodels and, thus, for the original model of nonlinear diffusion. For the received invariant submodels, we studied diffusion processes for which at the initial moment of the time at a fixed point is specified as a concentration and its gradient or as a concentration and its velocity. Solving of boundary value problems describing these processes is reduced to the solving of nonlinear integral equations. We established the existence and uniqueness of solutions of these boundary value problems under some additional conditions. The obtained results can be used to study the diffusion of substances, diffusion of conduction electrons and other particles, diffusion of physical fields and propagation of heat in inhomogeneous medium, and also to study a turbulence (Leith model, differential approximation to wave turbulence). © 2015 AIP Publishing LLC.