查询词典 thorium

The thorium abundance ratio measured for the star in the Ursa Minor dwarf galaxy is as low as that found in the oldest stars in the Milky Way, suggesting that this star could be at least 12 billion years old.

钍丰度比测得的星在URSA患者小矮星系是低至那被发现在古老的恒星在银河系中，暗示这颗恒星可能至少有12亿年之久。

Since the unstable nuclei exist between actinides, including thorium and stable nuclei like lead and bismuth, explosive events such as supernovae are required to produce actinides.

自不稳定核之间存在着锕系元素，包括钍和稳定核像灌了铅，铋，爆炸性事件，如超需出示锕。

The natural series are the thorium series, the uranium series, and the actinium series.

天然的放射性系是钍系、铀系和锕系。

All are radioactive heavy metals; and only the first four (actinium, thorium, protactinium, and uranium) occur in nature in appreciable quantities. The other 11 are unstable and are produced only artificially.

这些元素都是具有放射性的重金属；仅前四个元素是在自然界中存在的，其余十一个都不稳定且均为人造的。

Either of two decay products of thorium,mesothorium I,an isotope of radium,or mesothorium II,an isotope of actinium.

新钍钍的两种放射性生成物之一，即新钍1号，它是镭的同位素，或新钍2号，它是锕的同位素

It is important that studying gamma ray spectrometry of field rocks and soil in the earth抯 crust. Their energy range are mainly 30-3000keV, they contain abundant information of natural radioactive nuclides, such as uranium, thorium, potassium, etc, and of artificial radioactive nuclides from nuclear engineering activity, such as cesium, americium, cobalt, etc, and of the results in interaction between gamma ray and earth抯 crust.

国外近年已经生产出大于256道的伽玛射线能谱仪，但由于仪器应用滞后于仪器研究，且仪器稳谱未完全解决，获取全谱信息困难，加之对低能谱段的认识不足等原因，致使野外应用仍然滞留在仅限于测定铀钍钾含量的伽玛能谱测量水平上。

The determination of free acidity with the presence of rare ,uranium,thorium andiron,etc is studied.

研究了在稀土，铀，钍及铁等元素存在下自由酸度的测定，标准回收完全，适用于稀土料液自由酸度的测定

But an unexpected fact was noted: certain minerals (pitchblende, chalcolite, autunite) had a greater activity than might be expected on the basis of their uranium or thorium content.

但是一个意外的事实引起了我的注意：某些矿物质(沥青铀矿物质、铜铀云母或钙铀云母)的活性比根据其铀或针含量所判断的要高。

In 1903, a letter was written to nominate Pierre Curie and Becquerel. This letter gave Pierre credit for the discovery of thorium and radium and falsely reported that Becquerel and Pierre Curie worked side-by-side in the laboratory. In reality, they had never worked together.

在1903年，出现了一封提名皮埃尔·居里与昂利·贝克雷尔同时获取诺贝尔奖的信，信中赞扬皮埃尔·居里发现了钍和镭，但伪称贝克雷尔与皮埃尔·居里是并肩地工作在同一个实验室里，可是在实际上，他们从来没有在一起工作过。

The activity of thorium was measured by using a HPGe detector and a planar HPGe detector. 238 Th has been identified for the first time by measuring the growth and decay of the γ rays from its daughter nucleus 238 Pa.

使用两台高纯锗探测器测量了样品的γ射线活性，观测到了238Th的β－衰变子体238Pa的γ射线的生长、衰变行为，测定238Th的半衰期为9.4±2.0min

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。