短語詞組短語specific c impulse 比推力vacuum specific impulse 真空比沖standard measured specific impulse 標(biāo)準(zhǔn)實測比沖theoretical specific impulse 理論比推力;理論比沖optimum specific impulse 最佳比沖specific impulse efficiency 比沖效率pulsed specific impulse 脈沖比沖high specific impulse 高比沖 返回 specific impulse