tetrapolar sexuality

In this paper, a simple model of four-plate twisting section design is given for twisting up the main groove surface of the drill.

本文给出了搓制钻头主沟曲面的四板搓截形设计的简捷模型,并根据工程实际,实现了圆弧拟合,还给出了截形序列设计方案。

Theory of CDM additionality and calculation method of CO_2 emission reduction about the Sibangou hydropower station;

四板沟水电站清洁发展机制额外性原理及CO_2减排量的计算方法