allotropic transformation

例句：

1. 1. The allotropic transformation of a compound is the change in its physical properties when it undergoes a phase transition.
   化合物的同素异形体转变是指当它经历相变时，其物理性质的变化。
2. 2.During the allotropic transformation, the crystal structure changes from cubic to hexagonal.
   在同素异形体转变过程中，晶体结构从立方体变为六方体。
3. 3. The allotropic transformation of copper oxide from yellow to green is a fascinating example of how different environments can affect the properties of a substance.
   铜氧化物从黄色变为绿色的转变是一个有趣的例子，展示了不同的环境如何影响物质的性质。