对函数g()u(O)e例(β>0)取傅氏变换,可得 +0 GBo)= (t)u(t)e"e Jodt -Jo f(e(B+odt=f(t)esdt 其中s=B+j0,f()=q(t)u() B 若再设F(s)=j +oO 则得F(s)=f()edt5 对函数j(t)u(t)e-bt (b>0)取傅氏变换, 可得     + - + - + - + + - - - =       - = = + = = = = 0 0 0 ( j ) j ( ) ( ) e d j ( ) j , ( ) ( ) ( ) ( ) e d ( ) e d ( ) ( ) ( ) e e d F s f t t s F s G s f t t u t f t t f t t G t u t t s t t s t t t 则得 若再设 其中 b b  j  j b b  b  b