Petrographically and mineralogically similar rocks quite often have different concentrations of radioactive elements . 岩石学矿物学上类似的岩石，其放射性元素丰度却往往有所不同。
Very few alpha particles from radioactive sources can travel more than 1 to 3 inches in air before being stopped . 在空气中从放射源放出的粒子在停止以前只有很少能穿过13英寸的距离。
Because of the continuous decay, the quantity of radioactive material and the rate of emission of radiation decrease steadily . 由于连续衰变的结果，放射性物质的数量，辐射发射率都逐渐下降。
A person handling radioactive materials has no way of telling whether he is touching something too "hot" for safety . 一个处理放射性物质的人却无法断定他是否正在接触某种太“热”的危及安全的东西。
Practically every atom had its origin in the tiny violence of a radioactive disintegration some time within the past few billion years . 实际上每个原子都来源于过去几十亿年中某一时刻放射性分裂的微小激变。
Heat transfer coefficient，comprising convective and radioactive components may strongly depend on the actual flow enthalpy and density . 由对流和辐射两部分组成的热交换系数极大地依赖于实际活动的焓和密度。
From their work emerged the picture of radioactive decay that is still valid-a violently disruptive explosion of a single atom . 根据他们的工作，展现出至今仍然成立的关于放射性衰变的图象--单个原子的强烈的分裂性爆炸。
In the deep mantle the highest possible concentration of radioactive materials is limited by the condition demanding temperatures below the melting point . 在地幔深部，放射物质最高的可能浓度受溶点以下的温度条件所限制。
The cost for the deposition of the waste depends also upon the volume of the storage cavities and the maximum allowable radioactive concentration of the waste . 废料处理费用还取决于贮存空穴的容积和允许的废料最大放射性浓度。
