grading principle

• 分选原理

grading principle的用法和样例：

例句

1. This review elucidates the significance of developing air heavy medium fluidized bed separation technology.The principle of separation and bed characteristics are introduced.
   本文阐述了开展研究空气重介质流化床分选技术的意义，介绍了空气重介质流化床分选原理和空气重介质流化床的床层特性。