Affiliation: | (1) State Research Institute for the Rare-Metals Industry, Bol’shoi Tolmachevskii per. 5, 109017 Moscow, Russia;(2) Kursk State Technical University, ul. 50 Let Oktyabrya 94, 305019 Kursk, Russia;(3) Kursk State Pedagogical University, ul. Radishcheva 33, 305004 Kursk, Russia |