查询词典 radioactive decay

Radioactive series: Any of four sets of unstable heavy atomic nuclei that undergo a series of alpha decay and beta decay until a stable nucleus is achieved.

放射性系：四组不稳定的重原子核，通过一系列α衰变和β衰变直至达到稳定的核为止。

There are 8.6%~10.91% foreign matter in the sphenes, in which radioactive elements of strontium, cesium and uranium range from 4.26% to 4.58%. The change of structural cell parameters of sphenes is still very little,Δa=-0.0009 nm~0.0041 nm,Δb=0.0018 nm~0.0004 nm,Δc=0.0002 nm~0.0048 nm,Δβ=-0.10°~0.09° with high crystallinity of 99.27%~96.46%. Though, the age of sphene from the Fenghuang Mountain is about 1000 Ma, and experienced 775 Ma~1758 Ma geological evolvement and alpha decay, its crystallinity only decreased 3%, and its crystal shape and structure are still fine, indicating that sphene is of good ability to solidify radioactive elements. Therefore, sphenes are ideal minerals for solidifying nucleus waste.

通过对北祁连牛心山变质杂岩体中榍石(775Ma)和山西凤凰山花岗岩中榍石(1758Ma)的XRD及EDS等测试与研究，结果表明：两地榍石的杂质元素质量分数高达8.6%~10.91%，放射性核素锶、铯和铀的质量分数达4.26%~4.58%；晶胞参数的变化极小，△a=-0.0009nm~0.0041nm、△b=0.0018nm~0.0004nm、△c=0.0002nm~-0.0048nm、△β=-0.10°~0.09°，结晶度仍高达99.27%~96.46%，榍石经过10×10^8a的地质作用，结晶度仅减少了3%，显示榍石固化放射性系列核素的能力较强，虽经历了约775Ma~1758Ma的复杂地质演化及其所含放射性核素的衰变作用，其晶体结构完好，稳定性极高，是值得期待的理想核废物固化矿物。

The radioactive transformation giving rise to these electrons was known as beta decay.

产生这种电子的放射性变化，称为β衰变。

A better idea springs from the weak force , which governs certain nuclear processes, including radioactive beta decay. In 1964, physicists found that the weak force is not quite symmetrical in its dealings with matter and antimatter, resulting in something known as CP violation .

比较好的意见是后来突然提出来的称为"弱力"的理论，这种"弱力"控制了某些核过程，其中也包括了放射性的β衰变。1964年，物理学家发现弱力在处理物质和反物质是不完全对称的，此种结果称为宇称不守恒。

The decay of ~(99m)Tc source was used to verify experimentally that in the measurement of the number of atoms of a radioactive isotope in a sample at time t_0, the error introduced through the inaccuracy of its decay constant can be reduced to a much smaller value by the careful selection of the time of measurement or measurements of its radioactivity at around one life time (1/λ) after t_0 and doing the calculation.

本文用~(99m)Tc源的衰变实验证明了：在测量一个样品中在t_0时的一种放射性同位素的原子数时只需精心选择一次或多次测量其放射性的时刻在t_0后约该同位素的一个寿期(1/λ)，并进行计算，则由它的衰变常数或其半衰期(T1/2)的不准确性而引进的误差可以被降低到较小值。

The core of this model is a function called a stretched exponential relaxation, which is similar to the decay curve of a radioactive material.

这个模型的核心是延伸型指数函数的松弛效应，就像放射性物质的衰变曲线一样。

A highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium.

一种极不稳定的放射性元素，铀和钍腐烂的产物。

A highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium

a。 最多的；多数的，大部分的ad。最，最多；很，十分n。大多数，大部分a。最多的；多数的，大部分的

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。

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。属类：-〖化学

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。