This is the analogy to the alpha particle.

这和阿尔法粒子类似。

Upon gaining two electrons the alpha particle becomes a helium atom.

粒子获得两个电子之后就变成了氦原子。

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。

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。

Aluminium can be transformed, by the capture of an alpha particle and the emission of a proton, into a stable silicon atom.

铝可以通过俘获。粒子、排出质子而被蜕变成一种稳定的硅原子。