Alpha particles are these helium nuclei, and they are the result of radioactive decay.

阿尔法粒子是氦核，它们是放射性衰变的产物。

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It turns out that the diameter is actually 2 . 5 centimeters.

这个实验完成的很好,而且又没有放射性。

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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

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Because it is heavy you expect it is radioactive.

因为它的重，所以你想它应该是放射性元素。

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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

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As carefully as people work with radioactivity here, and using often much, much safer radioactive materials than radium bromide, and using them, and special hoods, and having special procedures, they still do a lot of checking with these Geiger counters to make sure everything's safe.

虽然在这里人们,用放射性物质都非常的小心，而且通常用的材料放射性,都比溴化镭要小得多，并且用的时候,都用特殊的容器,特殊的操作过程,但我们平时仍会用。

麻省理工公开课 - 化学原理课程节选

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