free diffusion

• 自由扩散

free diffusion的用法和样例：

例句

1. The sand in the bags has the principal task of guaranteeing continuity of contact in the material without impeding the free diffusion of the compressed air.
   袋中砂的主要目的是在保证材料的连续接触而不妨碍压缩空气的自由扩散。