hydraulic ram是什么意思

用法例句

This paper introduces research and development of DH pneumatic perforating machine, hydraulic percussion hammer and trajectory -controlled pneumatic perforating machine and their application.

非开挖技术在国际发展迅速，在我国尚有差距，本文介绍我国DH气动穿孔机、液压冲击锤、轨迹可控气动穿孔机的研制及工程应用情况。