v(x,t t)= ∑ 2bn丌 n-=1 (n)+(W)0x2a2(t-r)1nm n"(x)=∑2bmz e(-1) n2丌a(t-r sIn n=1 (n丌)+() ∑ 1-e(-1)nmx n丌at 2bn丌 SIr dt exp nta'r (nr)2+(k)2 0 (nz)+(k)公助以上 1-e“(-1)”1 nn a n丌at 2bn丌 ]-1} ∑ 26 { exp[-nTa't i (n)+(lk)nTa]sin ; ( ) exp[ ( ) ( ) 1 ( 1) ( , ; ) 2 2 2 2 2 1 2 2 l n x l n a t n lk e v x t bn n kl n       − − + − − =  = − ]; ( ) sin exp[ ( ) ( ) 1 ( 1) ( , ) 2 2 2 2 2 1 0 2 2 l n a t dt l n x n lk e u x t bn t n kl n II      − − + − − =   = − sin exp[ ] exp[ ]; ( ) ( ) 1 ( 1) 2 2 2 2 2 0 2 2 2 2 1 2 2 l n a dt l n a t l n x n lk e bn t n kl n         − + − − =  = − sin exp[ ]{exp[ ] 1}; ( ) ( ) 1 ( 1) 2 2 2 2 2 2 2 2 2 1 2 2 2 2 2 2 − − + − − =  = − l n a t l n a t l n x n a l n lk e bn n kl n       sin {1 exp[ ]}; ( ) ( ) 1 ( 1) 2 2 2 2 2 1 2 2 2 2 l n a t l n x n a l n lk e b n kl n     − − + − − =  = −