World War Two ended. Enrico Fermi had been the first to use a neutron to produce the radioactive change of one element to another.

VOA: special.2009.06.14

Suppose we've got some sort of radioactive atom, which has a certain chance of decaying.

假定我们有某种放射性原子,它们以一定的几率衰变

耶鲁公开课 - 死亡课程节选

4 And then there are the last four, carbon 14, which is a radioactive form.

然后，还有碳，以放射性形式存在。

麻省理工公开课 - 固态化学导论课程节选

But radioactive waste is a serious unresolved issue.

VOA: special.2011.03.18

For those of you don't know what that is it's simply an instrument that counts radioactive particles in the air, and MIT now that you're at MIT, you'll all have a chance to see one first hand if you're ever in any of the labs, especially in the chemistry or bio labs.

不知道它是什么,它就是一个简单的,计算在空气中放射粒子数目的仪器,你们现在来了，如果你们在实验室里工作的话,尤其是化学和生物实验室，你们有很多机会亲手用到它。

麻省理工公开课 - 化学原理课程节选

Florbetapir is a radioactive coloring agent.

VOA: special.2011.02.08

This label is DNA that might be made radioactive or made fluorescent, and it has a base pair sequence that is from some other region of the gene that you're interested in.

这种标签就是具有放射性,或者荧光性的DNA,它有一个取自于,你感兴趣的那段基因上,其他位置的碱基对序列

耶鲁公开课 - 生物医学工程探索课程节选

So,yes,there is a threat particularly of the use of radioactive material, although we have no specific evidence indicating any capability at this time."

VOA: standard.2009.05.01

And, he worked for a little less than 10 years at McGill where he did more work on these particles that radiate from radioactive elements.

他在McGill工作了将近10年,在McGill期间做了更多的,关于放射性元素的放射性的工作。

麻省理工公开课 - 固态化学导论课程节选

But the acquisition of radioactive material for a so-called 'dirty bomb,' which is radioactive material that is dispersed with a conventional explosive device, that is not that challenging.

VOA: standard.2009.05.01