isotopic composition

• 同位素组成

isotopic composition的用法和样例：

例句

1. This paper determined the sulfu risotopic composition of the Mianning REE deposit,Sichuan Province,China.
   分析了四川冕宁大型稀土矿床硫同位素组成。
2. The second epiphany was that the extracted gas had a significantly different isotopic makeup from what is usually produced in nuclear reactors.
   第二项大发现是，萃取出来的气体，同位素组成与一般核反应器中所产生的大不相同。