diffusion of impurities

例句：

1. 1. The process of diffusion is essential inchemical reactions.
   扩散过程在化学反应中至关重要。
2. 2.The diffusion of impurities can affectthe quality of the material.
   杂质的扩散会影响材料的质量。
3. 3. The diffusion of impurities is a complex process that requires carefulcontrol.
   杂质扩散是一个复杂的过程，需要仔细控制。