We have shown that it is possible to create a radioactivity characterized by the emission of positive or negative electrons in boron and magnesium by bombardment with alpha rays.

我们已经展示了人工放射现象的可能性，这种放射现象的特征是用以射线轰击用咄硼和镁中的正电子或负电子。

youdao

The second particle was deflected almost not at all. But what he could tell from the fact that there was a second particle at all, and the fact that it was in this direction, is that in addition to his negative particle, he also, of course, had a positive particle that was within this stream of rays that were coming out.

粒子的强烈信号,有着强烈的对比,第二个粒子几乎，不发生偏转，他能判断这是，第二个粒子的原因是它在这个方向,所以在出射射线中,除了有带负电的粒子外。

麻省理工公开课 - 化学原理课程节选

What that might be is unknown, but experiments in space have shown that cosmic rays can have some positive impacts on biological materials.

BBC: Earth News - Cosmic pattern to UK tree growth