河流的沉淀物中含有大量的放射性物质，这些放射性物质被暴风雨或洪水冲上河滩，使那里的土壤成为放射性污染源之一。
Its sediments remain highly contaminated and tainted floodplain soils that wash up during storms and floods have now become a source of radioactive materials.
真随机数发生器的熵源通常来自于真实的物理世界，如热噪声，大气噪声，放射性衰减甚至掷硬币。
TRNGs are usually based on physical phenomena such as thermal noise, atmospheric noise, radioactive decay and even coin-tossing.
为先驱者号们提供舱内热动力源的钚238会有放射性衰变，其发射量会随着时间的推移而越来越小。
As the plutonium-238 that served as the Pioneers' onboard heat source radioactively decayed, it would have emitted less heat over time.
应用推荐