设\(\Sigma\)是曲线段 \(\begin{cases}
x = e^y & (0 \leq y \leq a) \\
z = 0\end{cases}\)
绕x轴旋转一周所成曲面外侧，求
\(I = \iint_{\Sigma} \left( 2(1-x^2) \, dy \, dz + 8xy \, dz \, dx - 4xz \, dx \, dy \right)\)
设\(\Sigma\)是曲线段 \(\begin{cases}
x = e^y & (0 \leq y \leq a) \\
z = 0\end{cases}\)
绕x轴旋转一周所成曲面外侧，求
\(I = \iint_{\Sigma} \left( 2(1-x^2) \, dy \, dz + 8xy \, dz \, dx - 4xz \, dx \, dy \right)\)