| 1. | Natural radioactivity contains a store of valuable information .
天然放射性包含着许多有价值的信息。 |
| 2. | Alpha particles are positively charged helium nuclei obtained from natural radioactive decay .
粒子是从天然放射性蜕变得到的带正电的氦核。 |
| 3. | Natural radiation hazards in construction materials
建材的天然放射性危害现状分析 |
| 4. | How does natural radiation enter our body through the biosphere
天然放射性物质是怎样经过生物圈进入人体？ |
| 5. | Natural radioactive background
天然放射性本底 |
| 6. | Investigation on natural radioactivity level of building materials in fujian , china
福建省建筑材料天然放射性水平调查分析 |
| 7. | A good agreement between the theoretical and experimental results has made
通过对某区天然放射性水平扫面，给出了实验测量地区的分布及其特徵。 |
| 8. | Investigation on measurement methods for natural radioactivity in environmental geological survey of qingdao city
青岛市天然放射性环境地质调查中测量方法探讨 |
| 9. | Article 4 the provisions of the act do not apply to naturally occurring radioactive material , background radiation , and their exposure herein
第4条天然放射性物质、背景辐射及其所造成之曝露，不适用本法之规定。 |
| 10. | His work was done before the discovery of radioactivity and the understanding that natural radioactive decay provides a source of heat to the earth
他的工作是做了，才发现放射性和谅解，即天然放射性衰变提供热源，以地球。 |
