查询词典 uranium

Uranium isotope abundance ratio has been measured by total sample evaporation and signal integration, and a thermal surface ionization mass sepctrometry equipped with multicollector has been used.

采用全蒸发技术、离子流强度积分的方式，用多接收器热表面电离质谱计测量铀同位素丰度。

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。

A short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead.

一种存在周期短的放射性金属元素，由铀形成，能分裂成锕然后分裂成铅。

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。

Mineralogical characteristics, formation environments and environmental mineralogical significance of uranium acyl arsenate minerals in China are discussed systematically in this paper.

对我国产出的铀酰砷酸盐矿物的矿物学特征、形成环境和环境矿物学意义进行了较系统的综合论述。

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 extraction of americium,plutonium and uranium by dicyclohexano 18 crown 6(DCH18C6)/1 octanol from HNO 3 solution and simulated HLLW are studied.

研究了二环己基18 冠6（DCH18C6）－正辛醇从硝酸溶液和模拟高放废液中镅、钚、铀的萃取。

At low HNO3 concentration and dilution factor above 2, 0.1 mol/L DCH18C6/1-octanol extracts very little americium,plutonium and uranium.The distribution ratios of Am、Pu and U increase with the increase of HNO3 concentration in aqueous phase,and decrease with increasing of dilution factor of HLLW.The distribution ratio of extraction of Pu increases with the increase of extractant concentration.

研究结果表明，在低硝酸浓度和较大稀释倍数情况下，DCH18C6对镅、钚、铀的萃取分配比都比较小，并随着水相硝酸浓度的增大而增大，随着模拟高放废液稀释倍数的增大而减小，提高萃取剂浓度会增大四价钚的萃取。

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。

Subsequent redistribution of uranium in provinces formed at that time most probably resulted from orogenic processes and associated anatexis.

铀在成矿区内的重新分布，最可能是由于造山作用及伴随的泾熔作用。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。