d2x d2x f=m -k2x2=- kk2 x-m k +k2 dt2 d2x 伏海rU kk2 kk2 1 kk2 v= V(k +k)m 2π(k+k2)m k k k2 x2ki+kz 000000000000-■ 2 2 d d t x = mf 2 2 21 21 22 d d t x mx kk kk xk = + −=− x kk k x 21 1 2 + = mkk kk )( 21 21 + ω = ( ) 0 dd 21 21 2 2 = + + x mkk kk tx ( )mkk kk 21 21 2π 1 + ν = x k1 k2 o x