本文研究了无造渣剂等矿石粉的耐磨堆焊电焊条.An overlay welding electrode without mineral powder as, slag forming medium, etc.介绍了用高碳铬铁渣做造渣剂冶炼锰硅合金的生产实践.The practice of smelting ferromanganese silicon with slag of high carbon ferrochrome is intr...
他决定毕业后专攻昆虫学.He decided to specialize in entomology after graduation.纯理论昆虫学和应用昆虫学的众多领域都存在着研究机会。Research opportunities exist in a wide range of pure and applied areas of entomology.早在应用昆虫学发展的初期,就已开始植物抗虫性的研究.The study of pl...