radiochemical neutron activation analysis

例句：

1. 1. Radioactive materials are often used in medical imaging.
   放射性材料常用于医学成像。
2. 2. The researcher conducted a radiochemical analysis of the sample.
   研究者对样本进行了放射性化学分析。
3. 3. The study focused on the effects of radioactive isotopes on human health.
   该研究关注放射性同位素对人类健康的影响。