The first type discovered -- alpha decay -- is when a radioactive particle emits a Helium nucleus !

我们发现的第一种衰变方式——阿尔法衰变——是放射性粒子产生氦分子！

youdao

This is the analogy to the alpha particle.

这和阿尔法粒子类似。

youdao

And there he was able to identify the alpha particle as the helium nucleus.

他证实了，阿尔法粒子就是氦核。

youdao

And there he was able to identify the alpha particle as the helium nucleus.

他证实了,阿尔法粒子就是氦核。

麻省理工公开课 - 固态化学导论课程节选

This is the analogy to the alpha particle.

这和阿尔法粒子类似。

麻省理工公开课 - 固态化学导论课程节选

So basically he's trying to put some atoms in the way of the alpha particle.

把一些原子,放在alpha粒子的路径上。

麻省理工公开课 - 化学原理课程节选