氦是钍和铀元素数千年放射性衰变的副产品。
Helium is the by product of millennia of radioactive decay from the elements thorium and uranium.
这些矿物可以用放射性衰变技术测定年代，因为它们所含的放射性微量元素非常少。
These minerals can be dated by radioactive decay techniques because of the very small quantities of radioactive trace elements they, in turn, contain.
阿尔法粒子是氦核，它们是放射性衰变的产物。
Alpha particles are these helium nuclei, and they are the result of radioactive decay.
剩余核一般说来将发生一次放射性衰变。
The residual nucleus will, in general, undergo a radioactive transformation.
剩余核一般说来将发生一次放射性衰变。
The residual nucleus will, in general, undergo a radioactive transformation .
这项实验的关键因素在于放射性衰变是一个量子过程。
The point of the experiment is that radioactive decay is a quantum process.
卢瑟福首先认识到几率在放射性衰变中的作用。
Rutherford first identified the action of probability in radioactive decay.
化学也使用演算在确定反应速率和放射性衰变。
Chemistry also USES calculus in determining reaction rates and radioactive decay.
已将其用于实践的目的，去鉴别元素和阐明放射性衰变系。
It had been used for practical ends, to identify elements and to unravel radioactive decay chains.
与氦-4不同之处是，氦- 3不能由放射性衰变产生。
Unlike helium - 4, it cannot be produced by radioactive decay.
每个元素至少有一个同位素不稳定原子核可以进行放射性衰变。
Each element has at least one isotope with unstable nuclei that can undergo radioactive decay.
在海洋的大部分区域，海床都由厚重的粘土构成，最适合吸收放射性衰变产物。
Inlarge parts of the ocean, the seafloor is made of thick, heavy clay, perfectfor absorbing radioactive decay products.
量子隧穿发生在许多的物理过程中，比如说放射性衰变和太阳上发生的核聚变。
Quantum tunneling is involved in many physical processes, such as radioactive decay and the nuclear fusion that takes place in the Sun.
原子通过辐射由不稳定状态转变为更加稳定状态的过程称为放射性衰变或放射性。
The process by which an atom changes from an unstable state to a more stable state by emitting radiation is called radioactive decay or radioactivity.
然而，有些含氙同位素的矿物并非如此，是由铀的放射性衰变产生的。
However, some of the minerals contain xenon isotopes unlike those usually produced by radioactive decay of uranium.
它来自星际空间抵达地球的宇宙射线，来自土壤中矿物质的放射性衰变。
It results from cosmic rays reaching the earth from the outer space, and from the radioactive decay of mineral in the soil.
本文给出了氡子体浓度和通风、附着和沉积、以及放射性衰变之间的关系。
Mathematical relationship between Rn daughter concentrations and ventilation, adhesion and deposition, and radioactive decay was developed in the paper.
在中间尺度上，量子效应偶尔会被放大以致可被观察到，例如我们在测量放射性衰变的时候。
At an intermediate scale, however, they areoccasionally amplified to become observable, for example when wemeasure radioactive decay.
但是，相对于仅使用一个方法测试放射性衰变，研究人员测定时使用了三种元素，铅，钐，钕。
But rather than test the radioactive decay using just one method, the researchers used three, involving the elements lead, samarium and neodymium.
一种可能性就是内部岩石的放射性衰变，地球热量的0.025%来自于这种衰变。
One possibility is radioactive elements decaying inside rocks, which already give the Earth about 0.025 percent of its geothermal energy.
只有重力和一种可以支配某些放射性衰变的弱核力能够使其聚集凝固，“弱反应”这一术语由此得名。
Only gravity and a phenomenon called the weak nuclear force, which governs some types of radioactive decay, can bind them—hence the term “weakly interacting”.
放射性同位素，是指某种发生放射性衰变的元素中具有相同原子序数但质量不同的核素。
"Radioisotopes" refer to a certain type of elements producing radiation decay that have the same atomic number but different mass of nuclides.
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.
结果表明，三次样条方法在带有放射性衰变的水动力弥散方程的数值计算中，对抑制数值耗散是一种有效的方法。
It is shown that cubic spline method is effective for restraining numerical dispersion in numerical simulation of hydrodynamic dispersion equations with radioactive decay.
本文从原理上分析了采用舍选法进行随机抽样，得到符合放射性衰变统计规律的模拟计数值，并用TC进行了编程实现；
The principle of simulation of the statistics counting of radioactive nuclear decay based on the rejection method is presented, and the simulation is implemented with TC programming.
当氦衰变成为氦-3相对于我们在太阳里看到的那它就可用了，因为地球上多数的氦-4是通过元素铀和钍自然放射性衰变而造成的。
What helium is available is depleted in helium-3 relative to what we see in the sun, because most of Earth's helium-4 is freshly made via natural radioactive decay of the elements uranium and thorium.
之所以称其为“弱作用”，是为了指出粒子受到四大基本力中的另一种——由放射性衰变所产生的弱核力（四大基本力是：引力、电磁力、强力、弱力）。
By calling them “weakly interacting”, physicists mean that the particles experience another of the four fundamental forces, namely, the weak nuclear force that is responsible for radioactive decay.
普渡大学物理教授EphraimFischbach，将探测几种同位素的放射性衰变速率的方法作为一种没有人为输入因素干扰的产生随机数的可能方法。
Ephraim Fischbach, a physics professor at Purdue, was looking into the rate of radioactive decay of several isotopes as a possible source of random numbers generated without any human input.
普渡大学物理教授EphraimFischbach，将探测几种同位素的放射性衰变速率的方法作为一种没有人为输入因素干扰的产生随机数的可能方法。
Ephraim Fischbach, a physics professor at Purdue, was looking into the rate of radioactive decay of several isotopes as a possible source of random numbers generated without any human input.
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