,y,y)=/D1)=2)=2+y2+2) f()=a0(=x,y,z) f( B2( Vr+ ty2 v=a e a e 4zv2.a'e-pv dv= a m[ 4v4ae Bv dv=-m4a 33√丌/)32 8(B∴ ( ) ( ) ( ) ( ) ( ) ( ) 2 2 2 2 , , x y z x y z x y z f v v v = f v f v f v = f v = f v +v +v ( ) 2 2i v i f v e β α − = (i x = , , y z) 4 1 3 2 2 3 0 2 3 2 2 = ⎟⎟⎠⎞ ⎜⎜⎝⎛ ⋅ = − ∝∫ βπ π α α β v e dv v m v e dv m kT v 2 1 3 8 3 4 2 1 4 2 1 3 2 2 3 0 4 3 2 2 = = ⎟⎟⎠⎞ ⎜⎜⎝⎛ ⋅ = ⋅ ⋅ − ∝∫ ε β π π α πα β ( ) ( ) 2 2 2 2 2 2 3 3 x y z v v v v f v e e β β α α − + + − = =