双重星系或天体系统，用动力学方法测定其质量时，观测到的视向速度和距离间距，都是各自值的投影值，可用统计方法，求出一个关于它们的平均投影因子。
Both of the observed radial velocity and separation being projective values, in order to determine the mass of binary galaxies the average projection factor may be derived by a statistical method.
并按质量标准研究的技术要求，对药材及制剂进行了系统的鉴别、检查、浸出物测定及含量测定等项研究。
According to the technical demands of quality standard of new drug, the author has studied systematic identification test of extraction and content assay of Rhiroma Menipermi.
该系统能快速测定型砂的有效粘土含量和含水量，实现型砂质量的直接控制。
The system can test active clay content and moisture of green sand fast and control its composition directly.
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