文档介绍：In the 100 elements available to us, about three quarters can be classified as metals. And, about half of these are of at least some industrial mercial importance. Metals, be they pure or alloy, can be further defined as being ferrous or nonferrous in make up. Ferrous alloys are those in which the base or primary metal is iron, manganese, chromium. All other metallic materials automatically fall into the non-ferrous category(范畴).
在人类可获得的一百多种元素中,约四分之三是金属。而这些金属中又大约有一半至少在工业或商业上具有一定的重要性。所有的金属,不管是纯金属还是合金,都能根据成分进一步分成黑色金属或有色金属。黑色金属主要是以铁、锰、铬为主要成分的合金,其余金属材料自然都属于有色金属的范畴。
Direct reduction offers a number of advantages including low investment expenditure and the use of cheap primary energy instead of coke. Consequently, this technique offers may developing countries the possibility of building up a national steel industry. In fact, direct bined with electric arc furnace must in future be considered among the important steel production techniques alongside the blast furnace and oxygen converter technique.
直接还原法具有一些优点,包括低投资成本和使用廉价的原始的能源代替焦炭,所以这种技术为许多发展中国家提供了建设国家钢铁工业的可能性。事实上,与电弧炉结合,直接还原在今后与高炉和吹氧转炉技术一样一定会成为重要的钢铁生产技术。
In September 2004, the National Cancer Institute announced an initiative to bring new blood to an old and desperate fight. Called the NCI Alliance for Nanotechnology in cancer, the initiative will wager $ million over the next 5 years that nanotechnology will open entire