contrastes

The paper contrastes and analysies the marking for the coarse degree ...

本文新旧标准中表面粗糙度标注进行分析。

This paper introduces studying and using process of new type polyurethane sealing element,contrastes with similar import sealing element.

介绍新型聚胺脂密封件研究开发和过程,并与进口同类密封件进行,有一定价值。