寻找石油的等差级数是严格的。

The arithmetic searching for oil is stark.

根据D-n曲线可导出粗纱层厚是按等差级数递增的。

The roving layerarithmetic progressionally increasing according to D-N curve is concluded later.

用动量守恒定律和数学中等差级数的极限证明了火箭速度公式的两种形式是一致的。

By adopting the momentum conservation theorem, perforation of truncated oval-nosed projectile into stiffened plates was investigated.