我们知道改变内能的方式有两种,一种是做功,一种是热传递,热力学第一定律恰当的表达了内能的改变与热和功之间的关系:△U=W +Q,可是同学们在考虑用做功的方式改变物体的内能时,往往只考虑到外界和系统之间的那些比较直观的作用现象,如外界压缩系统,系统膨胀而对外做功,摩檫生热等,而忽略了系 We know that there are two ways to change internal energy. One is work, and the other is heat transfer. The first law of thermodynamics properly expresses the relationship between changes in internal energy and heat and work: △ U = W + Q, However, when students consider changing the internal energy of an object in the way of doing work, they often only consider the relatively intuitive effects between the outside world and the system, such as the external compression system, the system expansion and external work, friction heating, etc. And ignore the Department