1.12dA·ds=.A·ds+dA·ds+dA·ds 2 =Ae, 5dpz+Aoe rdp.dz-Aoerdpdr 2丌 125do dz+ rdr 8d0+0 25 2丌·125.4+.8·2兀=1200兀 VA=3r+2 V Adr=l(3r+2)rdrdodz=1200T 115φAde=φ(Adx+A,dy+Adz) xdx+ 4dy+ xdx+ Ody=8 0 0 01 2 3 1 1 3 2 4 5 2 0 0 0 0 1.12 . . . . . 5 . . . 125 8 0 25 2 125 4 8 2 1200 2 3 s s s s r z z s s s A d s A d s A d s A d s A e d dz A e rd dz A e rd dz d dz rdr d A r           • = • + • + • = • + • − • = + + =   +   =  • =            2 2 0 2 0 0 2 0 2 (3 2) 1200 1.15 ( ). 4 . 0 8. x y z Ad r rdrd dz A de A dx A dy A dz xdx dy xdx dy  +  • = + =    • = + + = + + + =        