positron

例句：

1. 1.The positron emission tomography (PET) scan is used to detect cancer cells in the body.
   正电子发射断层扫描用于检测身体内的癌细胞。
2. 2. The researchers found that the positron emitted from the atoms had a significant impact on the surrounding environment.
   研究人员发现，从原子发射出的正电子对周围环境产生了显著影响。
3. 3. The positron decay process is a fundamental part of nuclear physics.
   正电子衰变过程是核物理的一个基本组成部分。