V.V. Zemlyakov - Ph. D. (Phys.-Math.), Associate Professor, Southern Federal University (Rostov-on-Don). E-mail: vvzem@yandex.ru
G.F. Zargano - Dr. Sc. (Phys.-Math.), Professor, Southern Federal University (Rostov-on-Don). E-mail: zargano@yandex.ru
S.V. Krutiev - Student, Faculty of Physics, Southern Federal University (Rostov-on-Don). E-mail: sergey-kryt@yandex.ru