历忠毛子种技大字 XI UNIVERSITY n(4 r(t) (a) R·1(1)t≥0 Rt≥0 r() t≥0 r() 0 t<0 0t<0 r(s=L[r(tJ r(s)=L[r(o] r(s)=L[r() L[R·1()] =LIR.t L[A []        0 0 1( ) 0 ( ) t R t t r t ( ) [ ( )] [ 1( )] 1 r s L r t L R t s            0 0 0 ( ) t Rt t r t 2 ( ) [ ( )] [ ] r s L r t L R t A s             0 0 0 ( ) 2 2 t t Rt r t 2 3 ( ) [ ( )] [ ] 2 r s L r t L A t A s    