该立体投影到xoy面为x²+y²=2y,即Dxy：x²+(y-1)²=1,其极坐标方程为：r=2sinθ∫∫∫zdv=∫∫ (∫[0--->2y]zrdz) drdθ=∫∫ (∫[0--->2rsinθ]zrdz) drdθ=1/2∫∫ z²r |[0--->2rsinθ] drd...