一种碳的天然放射性同位素，原子量为4，半衰期为5，780年，用于测定古代生物标本，地质标本或考古遗迹的标本的年代。

A naturally radioactive carbon isotope with atomic mass 4 and half-life 5,780 years, used in determining the age of ancient organic, geologic, or archaeological specimens.

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测定了在该泉水中养殖的鱼类及用该泉水灌溉生长的农作物和其他有关环境生物样品中天然放射性物质的含量。

The natural radioactive substance content was determined for fishes, in thermal spring water, farm products irrigated with such water and other biological samples.

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采用生物效价与放射免疫分析两种方法对微粒剂胰岛素含量进行测定。

The contents of INS MP were measured by the method of the insulin biopotency and radioimmunoassay(RIA).

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