The developments and current situation of tantalum-niobium hydrometallurgical extraction are presented. 介绍了钽铌湿法冶金技术的发展概况和现状。
This paper gives a general review of historical development of engineroom automation with present circumstances of shipping companies in this area. 本文回顾了我国机舱自动化的发展概况和目前机舱自动化技术方面的状况。