particle gradation的用法和样例：
例句
- Its main work includes the Yellow River sediment cross-section tests, river bed surface quality sampling and particle size distribution analysis and so on.
其主要工作内容包括黄河河道断面淤积测验，河道表层河床质取样及颗粒级配分析等工作。 - The improvement of cement particle distribution and heating intensity during clinker burning could also improve the performance of cement for pipe pile manufacturing.
改善水泥颗粒级配和提高煅烧热力强度均能改善管桩水泥的性能。
