α m k 1 k 2 m m k 1 k 2 m B mm k l 0 l l max A A m m m k 2 k 1 m k 2 k 1 m k 2 k 1 α m α m A V m A V V C LR BA C LR BA C LR BA C LR B A V V C LR B A V C B L, r A R A B C R A B C L, rR BA LR BA C L, rR BA C L, r Q B V P A