He says it is an all-out shutdown. Regularly scheduled tours of South Korea's side of the heavily armed inter-Korean border were abruptly curtailed Thursday after the North's announcement came out, as a safety precaution.

VOA: standard.2010.05.27

So use work out of right-hand side to run left-hand backward.

利用右边输出的功,来驱动左边的热机反方向运行。

麻省理工公开课 - 热力学与动力学课程节选