现行初中物理关于做功和内能的改变有两个演示实验，实验１演示的是空气被压缩时内能增大，效果明显，易于操作；而实验２演示的是物体（空气）对外做功时内能减小，虽然简单易行，但现象不是很明显，特别是容器中应该出现的雾不易清楚地被观察到。为此，我对此实验装置作了改 The current junior high school physics has two demonstration experiments on the changes of work and internal energy. Experiment 1 shows that the internal energy can be increased when the air is compressed, the effect is obvious, and it is easy to operate; while the experiment 2 demonstrates that when the object (air) performs external work, It can be reduced. Although it is simple and easy, the phenomenon is not obvious. Especially the fog that should appear in the container is not easily observed. For this reason, I made a change to this experimental device.