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了析。

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

介绍了新型聚胺脂密封件研究开发和用过程,并与进口同类密封件进行,有一用价值。