但其排气速度却异常惊人，大约为化学燃料火箭的十倍—这使得离子推进器的效率非常高。
The exhaust velocity, though, is enormous—more than ten times that of a chemical rocket—and this makes ion propulsion extremely efficient.
并进一步分析了基岩厚度、采高、推进速度对顶板破断的影响。
The effect of basic rock thickness, mining height and advancing speed on roof breaking is analyzed.
并进一步分析了基岩厚度、采高、推进速度对顶板破断的影响。
The effect of basic rock thickness, mining height and advancing speed on roof breaking is analyzed.
应用推荐