positron emission

例句：

1. 1.Positron emission is a process in which positrons, a type of antimatter particle, are emitted from a nuclear reactor.
   正电子发射是一种过程，其中正电子，一种反物质粒子，从核反应堆中发射出来。
2. 2. In positron emission tomography (PET), positrons are used to detect the presence of glucose in the brain.
   在正电子发射断层扫描
3. 3. The study of positron emission has led to important discoveries in the field of radioactivity.
   正电子发射的研究在放射性领域取得了重要的发现。