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稀土是15个镧系元素和另外2个同属元素周期表第三副族中钇和钪共17个元素的总称。它们有许多优异性能和多种用途,是宝贵的自然资源。稀土现已被开发应用于生物、农业、石化、医药、电子、冶金等广泛领域,并取得了显著的经济效益。据报导,稀土元素具有改善树木酶的活性,提高叶绿素含量和光合作用强度,促进营养元素的吸收和营养积累、增强其抗逆能力等生理功效。1997年4月和8月我
Rare earth is a collective term for 15 lanthanides and a total of 17 elements of yttrium and scandium in the third subgroup of the same belong to the same periodic table. They have many excellent properties and many uses that are valuable natural resources. Rare earth has been developed and applied to biological, agricultural, petrochemical, pharmaceutical, electronics, metallurgy and other fields, and achieved significant economic benefits. It has been reported that rare earth elements have the physiological effects of improving the activity of the tree enzyme, increasing the content of chlorophyll and photosynthesis, promoting the absorption and nutrient accumulation of nutrient elements, and enhancing their resilience. April and August 1997 I