Water was the main source of mechanicalpower, and by the end of the seventeenth century, England alone is thought to have had some 20,000 working mills.
水是机械动力的主要来源,而到了17世纪末,人们认为仅英格兰就有2万个左右的工作磨坊。
2
Valve actuation utilizes a mechanicalpower device, an actuator, to operate a valve.
阀门执行机构是一种采用机械力的设备,一台执行机构操作一个阀门。
3
However, some are still not efficient enough to turn chemical energy into mechanicalpower.