查询词典 sealed radioactive source

Radioactive decay of radium-226, found in a wide variety of rocks and soil.

这种氡可以在很多种类的石头和土壤中找到。

Radon is a gas that comes from the radioactive decay of radium in rocks.

氡是来自岩石中镭辐射衰变而产生的一种气体。

Its stable isotope s are all end products of radioactive decay of uranium and other heavy elements.

其稳定的同位素为铀和其它重金属放射衰变后的最终产物。

Its stable isotopes are all end products of radioactive decay of uranium and other heavy elements.

其稳定的同位素为铀和其它重金属放射衰变后的最终产物。

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。

The immediate product of the radioactive decay of an element.

一种碱金属属的放射性元素，是锕瓦解的产物。

Atoms in a radioactive substance decay in a random fashion but at a characteristic rate.

原子的放射性物质衰变的随机方式，但利率的一个特点。

Beneath the Earth's crust lies the mantle which is heated by the radioactive decay of heavy elements.

地壳的下面是地幔，由于有重元素的放射衰变活动所以温度较高。

Geological dates are usually obtained by using the rates of decay of various radioactive elements found in minerals.

人们通常用矿物中所发现的各种放射性元素的衰变率来计算地质年代。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。