N.K. Yurkov1, E.A. Danilova2, I.I. Kochegarov3, A.V. Lysenko4, I.M. Rybakov5

1-5 Penza state University (Penza, Russia)

1 yurkov_nk@mail.ru; 2 siori@list.ru; 3 pgu.kipra@yandex.ru; 4 lysenko_av@bk.ru; 5 rybakov_im@mail.ru