polycrystalline unit

例句：

1. 1.The polycrystalline structure of the material is responsible for its high strength and toughness.
   这种材料的多晶体结构是其高强度和韧性的原因。
2. 2. Polycrystalline materials are often used in electronic devices due to their excellent electrical conductivity.
   由于其出色的电导率，多晶体材料常用于电子器件中。
3. 3.The polycrystalline nature of the material allows it to be easily shaped into various shapes and sizes.
   材料的多晶体性质使其能够容易地被塑造成各种形状和尺寸。