double coated

At the beginning and the end of the 20th century, there were twice cultural arguments among Chinese ideological area.

20世纪始末,中国思想界就中国文化问题进行过两次大的论争,其围绕的核心问题基本相同,即资产阶级自由主义;文化民族主义;社会主义。

In the two-time upsetting and stretching technology,the choice of anvil ratio W/H of wide and high,blank ratio B/H of wide and high,forging ratio △H/H every time is an important supplement of WHF forging method.

总结的两次镦拔锻造新工艺具有可靠性高,锻透效果好,可控制钢中夹杂物的形态和对坯料内部缺陷进行修复的独特作用,是一种新颖的大锻件锻造工艺。

The paper introduces the trial-producing process of the thick wall seamless steel tube using the technology of first perforation and secondary perforation.

文章介绍了采用了一次穿孔和两次穿孔技术生产厚壁无缝钢管的试制工艺过程,并对所生产的五个系列产品进行了检测,结果表明产品的尺寸精度、表面质量和力学性能均满足相关标准及用户的要求,具备批量生产能力。