free volume的用法和样例：
例句
- The positron annihilation technique was applied to study the relation between relative free volume and irradiated graft for PTFE.
用正电子湮没技术研究在聚四氟乙烯辐照接枝过程中的自由体积与正电子湮没寿命谱的关系。 - With the augmentation of grain size, surface defects of the manganese zinc ferrite nanocrystallines minish, and intergranular free volume combines.
随着粒径的增大，纳米晶的表面缺陷减小，晶界间的自由体积发生复合。
