E.N. Sidorenko - Ph.D. (Phys.-Math.), Associate Professor, Southern Federal University. E-mail: si-do-re@mail.ru, ensidorenko@sfedu.rsu.ru V.G. Gavrilyatchenko - D.Sc. (Phys.-Math.), Professor, Southern Federal University. E-mail: gavrilyatchvg@sfedu. ru A.V. Turik - D.Sc. (Phys.-Math.), Professor, Southern Federal University. E-mail: turik@phys.rsu.ru A.F. Semenchev - Ph.D. (Phys.-Math.), Associate Professor, Southern Federal University. E-mail: aleksasha@ phys.rsu.ru I.I. Natkhin - Assistant, Southern Federal University