positron beam

例句：

1. 1.The positron beam was used to map the brain's structure.
   正电子束被用来绘制大脑的结构。
2. 2. The researchers used the positron beam to study the properties of matter.
   研究人员使用正电子束来研究物质的性质。
3. 3.The positron beam was crucial in the development of new medical treatments.
   正电子束在开发新的医疗治疗方法中起着关键作用。