放射性衰变

Radium does not occur free in nature but occurs in natural ores such as pitchblende as a disintegration product of radioactive decay of heavier elements, including uranium.

在自然界镭不存在游离状态，但存在于天然矿石中，如沥青铀矿，是更重元素放射性衰变的产物。

Radium does not occur free in nature but occurs in natural ore s such as pitchblende as a disintegration product of radioactive decay of heavier elements, including uranium.

在自然界镭不存在游离状态，但存在于天然矿石中，如沥青铀矿，是更重元素放射性衰变的产物。

The point of the experiment is that radioactive decay is a quantum process.

这个实验的关键点是放射性衰变是一个量子过程。

The point of the experiment is that radioactive decay is a quantum proces s.

这项实验的关键因素在于放射性衰变是一个量子过程。

It had been used for practical ends, to identify elements and to unravel radioactive decay chains.

已将其用于实践的目的，去鉴别元素和阐明放射性衰变系。

However, some of the minerals contain xenon isotope s unlike those usually produced by radioactive decay of uranium

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。

Each element has at least one isotope with unstable nuclei that can undergo 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。

Scientists now believe it is a combination of radioactive decay and tidal heating [ 59 ] [ 60 ] , as tidal heating alone is not enough to explain the heat.

科学家现在相信，这是放射性衰变和潮汐热 [59] [60]的组合，如潮汐热不足以解释热量。

Chemistry also uses calculus in determining reaction rates and radioactive decay.

化学也使用演算在确定反应速率和放射性衰变。

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。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。