Let d= ac dC x dc n at dn 2tt dn 2t ac dc an1 dc Oxdλax d 0C、d dC、0λ1ddC D )=(D axax d2 √t d"ax/td2dλ put(4)in(1 2 dc 1 d dc (D 2t da t dt dnLet (3) t x  = ) (4) 2 ( d d ) 2 ( d d t C t t C x t C    = − = −   ( ) ( ) ) d d ( d 1 d d d 2 put 4 in 1    C D t t C t － = （ ）         d d d 1 d ) d 1 d ( d d ( ) d 1 d d d C x t C t D x C D x C x t C x C =   =       =   =    t 1