The meteorite , which recently fell to the tropical island in pacific ocean , proved to be the present well of the thinnest radioactive isotope 最近落到在太平洋的热带岛陨石证明是最薄的放射性的同位素的现在井
Autoradiography a technique whereby a tin slice of tissue containing a radioactive isotope is placed in contact with a photographic plate 放射自显影术:将含有放射性同位素的一小薄片生物组织与感光层接触的一项技术。
The importation of the radioactive isotope , radiation equipment and other radioactive materials should come up to applicable state regulations 进口放射性同位素、射线装置和含有放射性物质的物品的,按照国家有关规定办理。
We can talk about the half - life of a radioactive isotope , and indeed we can measure and state very very precisely what that half - life is 我们可以谈论放射性同位素的半衰期,我们确实可以非常准确地测量和描述半衰期是什么。
Gamma rays have proved very helpful in medicine and industry . these rays are also given off by radioactive isotopes obtained as by - products in production processes 射线已被证实在医学和工业上有很大的用处,这些射线是在生产过程中由放射性同伴素释放出的副产品。