x(x∈R2,t>0) ulio=o(x) (1) l=0=v(x) Wn=aWx(x∈R,t>0) (2) W|≥=o=0 (1)的解为 (02=5[0(x+a)+(x-a)]+2 X+at 2a ()d5 x-at0.8 1 0.6 0.4 0.2 0 x t 0 0.5 1 1.5 2 −1 −0.5 0 0.5 1 n 15 2 0 0 ( , 0) ( ) (1) ( ) tt xx t t t V a V x R t u x u x   = =  =     =  =  (1)的解为： 2 0 0 ( , 0) 0 (2) 0 tt xx t t t W a W x R t W W = =  =     =  =  ( ) ( ) ( ) . . 1 1 ( , ) 2 2 x at x at V x t x at x at d a      + − = + + − +     