unit volume expansion

例句：

1. 1. The expansion of the unit volume can affect the overall performance of the system.
   单位体积的膨胀会影响整个系统的性能。
2. 2.During the expansion, the material will expand and contract repeatedly.
   在膨胀过程中，材料将反复地扩张和收缩。
3. 3. The expansion of the unit volume is a crucial factor in determining the stability of the material.
   单位体积的膨胀是决定材料稳定性的关键因素。