·2,447,543篇论文数据，部分数据来源于NoteExpress
N an element that is naturally radioactive 放射性元素
radioactive element
The radioelement content of certain material is higher, when its intensity and radiation dosage exceed certain limit, can cause a harm to human body.
某些材料的放射性元素含量较高，其强度和辐射剂量超过一定限度时，就会对人体造成危害。
youdao
应用推荐
模块上移
模块下移
不移动