l(x,y,1)=∑∑ Amm exp[(n2+ n丌 n7 B>]sin SIn b n=I m a sin -sin ∑∑ a sin sIn b nm n=1m=1 b A=Amn(n=1,m=2)其它An=0 丌24丌 2 270v (x y, t)=Aexp -(2+a sinsin b bb m y l n x a t b m l n u x y t A n m n m     ( , , ) exp[ ( ) ]sin sin 2 2 2 2 2 2 2 1 1 = − +  =  = b m y l n x A b y l x A n m n m     sin sin 2 sin sin 1 1   =  = = A = Anm b y l x a t l b u x y t A    2 ) ]sin sin 4 ( , , ) exp[ ( 2 2 2 2 2 = − + (n =1,m = 2) = 0 其它 Anm