我们现在的氦源，是地下天然气田中放射元素衰变的副产品，经过数十亿年的累积，逐渐形成的。
Our modern supply of helium has gradually built up over billions of years in subterranean pockets of natural gas as a byproduct of decaying radioactive elements.
氡是天然放射性惰性气体，是铀系衰变链中的一个衰变产物。
As a product from the uranium disintegration, radon is a natural radioactive idle gas.
研究了放射性气溶胶监测仪的检测方法，即天然本底检测法和衰变检测法。
Two test methods, natural radioactive background method and decay method, used to verify the detection limit of radioactive aerosol monitors are studied.
因为它是稀有天然放射性同位素钾衰变而产生的，所以可以用来测定十万年以上的岩石年龄和采样。
Because a radioactive form of argon is produced by decay of a naturally occurring radioactive potassium isotope, it can be used to date rocks and samples more than 100,000 years old.
因为它是稀有天然放射性同位素钾衰变而产生的，所以可以用来测定十万年以上的岩石年龄和采样。
Because a radioactive form of argon is produced by decay of a naturally occurring radioactive potassium isotope, it can be used to date rocks and samples more than 100,000 years old.
应用推荐