稀土是指元素周期表中镧系包括镧、镨、钕、钷、钐、铕、钆、铽、镝、铒、铥等17种金属元素的总称。其中铱占48%,镧占25%。钕占16%,镨占5%,钐占2%,其它12种元素占4%。近年来,稀土已成为国民经济和国防建设的重要资源。不仅可作为工业维生素广泛用于冶金、机械、石油、化工、轻工、电子等行业,而且可作为微肥,用于农业生产。在渔业生产中,鱼喂稀土也有很好的效果。据试验,鱼喂稀土可产生三大功能:一是有调节鱼体代谢功能,提高鱼类对养料的利用率,使鱼类加 Rare earth refers to the periodic table of lanthanum, including lanthanum, praseodymium, neodymium, 钷, samarium, europium, gadolinium, terbium, dysprosium, erbium, 铥 and other 17 kinds of metal elements in general. Among them, iridium accounts for 48% and lanthanum accounts for 25%. Neodymium accounts for 16%, praseodymium accounts for 5%, samarium accounts for 2%, other 12 kinds of elements account for 4%. In recent years, rare earth has become an important resource for national economy and national defense construction. Not only as an industrial vitamin widely used in metallurgy, machinery, petroleum, chemical, light industry, electronics and other industries, but also as a fertilizer, for agricultural production. In fishery production, fish feed rare earth also has good effect. According to the test, fish fed rare earth can produce three major functions: First, there is a regulation of fish metabolism, improve the utilization of nutrients on the fish, so that fish plus