九年义务教育三年制初级中学教科书《物理》(人教版)第一册第四章第三节《熔化和凝固》,在讲晶体的熔化和凝固时,设计的实验是观察海波(或冰)的熔化。笔者曾多次按课本的要求做这个实验,但很难观察到海波在熔化过程中温度不变的现象,而且这个实验设计的是 Nine-year Compulsory Education Three-year primary school textbook “Physics” (PEP) Volume IV Chapter IV “Fusing and Solidification” When designing the melting and solidification of crystals, the design experiment is to observe the Haibo ( Or ice) melting. The author has done this experiment several times in accordance with the requirements of the textbook, but it is difficult to observe the phenomenon that the temperature of the sea wave is not changed during the melting process, and this experiment design is