罗布泊地貌地质遗迹中某些元素的分析

用中子活化分析法测试了新疆罗布泊地区地质样品中的某些痕量、微量及常量元素含量,特别是对样品中放射性元素作了检测。结果表明,该地区的地质遗迹样品中,痕量、微量及常量元素的含量与中国大陆地壳中的含量相当,无明显的放射性异常;把这些样品当作建筑材料的原材料来使用,是安全的;通过对这些样品的检测分析,为该地区的化探普查提供了可靠的依据。     

中子活化分析在鄂尔多斯地区元素分析中的应用

利用中子活化对鄂尔多斯盆地油气田上方的地质样品进行了某些元素的检测,通过实验分析,得到了该地区岩石中某些元素的含量,并对该地区的放射性元素作出了评价,绘制了样品的稀土配分模式图和评价了当地的金属矿产资源情况.结果表明,在油气田的上方,放射性元素铀呈现出负异常;钍和钾无明显异常;岩石中的其它元素和中国大陆地壳元素丰度基本...     

钐同位素丰度的绝对测量

建立了钐同位素丰度高精度的质谱测量法。对样品形态选择、离子转换效率、离子传输效率和离子接收效率进行研究,消除了浓缩同位素测量时强峰拖尾对弱峰的干扰及同量异位素干扰。用已知化学纯度的^152Sm、^154Sm两种浓缩同位素,通过化学计量配制人工合成校正样品,测量质谱计的系统误差校正系数,对用该仪器测量的来自不同地域矿物和试剂样品中钐元素天然同位素的丰度比数据进行校正,准确求得钐同位素的丰度。     

新疆罗布泊土壤微量元素含量研究

以罗布泊外围区为研究区域,通过对该地区土壤中微量元素含量的测定,分析探讨了该地区土壤中微量元素的含量范围及影响因素,以期对该地区土壤的放射性核素污染修复研究提供数据和理论依据。     

激光诱导等离子体光谱元素成像技术研究进展及其在核材料检测领域的应用

激光诱导等离子体光谱元素成像技术以其具备测量不受辐射本底影响,测量速度快,样品制备相对简单,可远程分析放射性样品等优势在核材料检测领域展现出巨大的潜力。本文将激光诱导等离子体光谱元素成像技术分为成像系统和数据处理两个方面进行介绍,并对其研究进展和在核材料检测领域的应用进行综合分析,最后总结了LIPS元素成像技术的优势与面临的挑战,对LIPS元素成像技术在核材料检测领域的发展趋势进行展望。     

水性漆污泥中钛元素的赋存状态研究

工业固体废弃物中金属元素的赋存状态是判别废弃物种类的重要指标。采用现代分析测试手段对水性漆污泥样品中钛的赋存状态进行了研究。实验表明,该污泥样品中钛元素赋存于氧化钛和钙钛矿中,其中95.82%存在于氧化钛中,4.18%存在于钙钛矿中,未检测出水溶性钛。在自然环境中,该样品中的钛元素以较稳定形式存在,不会对环境产生影响。     

微量元素在生物体内的含量与分布

在生物与环境进行的物质交换中,生物从环境中吸收物质,服从于生物选择元素的丰度规则、效率规则和基本匹配规则。这就决定了生物体内元素的含量与环境中该元素的含量成正比。因此,作为生物环境的土壤、水和空气中微量元素含量的改变,必将引起食物链起始环节元素含量的变化,引起人体内必需、无害及有害微量元素含量的变化,影响人的生理功能,进而造成对健康的影响甚至形成疾病。现已知对植物生长最重要的20种元素是:碳、氧、氢、磷、钾、钙、镁、硫、氮、铁、锌、铜、锰、硼、钴、钒、氯、钠和硅等。前8种元素占植物质量的99·76%,其余的元素仅占0·24%。微量元素的含量不仅在不同的生物体内,就是在同一生物体内的不同组织部位和发育阶段也不相同。同时还与环境中该元素的含量及其易被吸收的程度等特性和水文地球化学条件有关。植物主要从土壤中吸收矿质营养,因而土壤中某些元素的含量高(特别是可溶性的有效成分),则该元素亦有较多的数量进入植物体内,同样,食物、空气及饮水中含量高的元素,动物体内该元素的含量也高。即环境中某元素的含量与生物体内该元素的含量成正相关关系。据此可知,受某些元素污染的土壤所生长的植物体内,该污染元素的含量亦高。当然,这种总体的一致...     

云南某金矿金与伴生元素的某些特征

采用中子活化分析方法研究了云南某金矿区内的硅化褐铁矿化石英砂岩类、辉绿岩类、灰岩类和黄铁矿样品的微量元素特征,并利用元素地球化学研究方法对元素间的相关关系进行了分析.结果表明,在该地区利用金的伴生元素来指导找矿,可提高金的找矿效益.     

加速器质谱法测定环境和生物样品中的129I

建立了环境和生物样品中的129I的分析方法,采用碱式灰化、萃取-反萃、沉淀等步骤对环境和生物样品中的碘进行预浓集,用131I[NaI] 为放射性示踪剂优化各分步的制备条件,运用加速器质谱法测定了北京地区松针和干草、青岛地区海藻和海水中的129I/127I.用超热中子活化法测定样品中的稳定碘(即127I)含量.上述松针、干草、海藻和海水样品中的129I/127I分别为8.11×10-9、5.97×10-9、1.70×10-10和6.05×10-10;相应的129I浓度分别为3.22×10-15、1.24×10-14、1.27×10-14 g/g干重和2.30×10-14 g/L.与文献报道值相比,我国与国外同类地区相当甚至更低,比法国和英国乏核燃料后处理厂附近环境中的129I低2～3个数量级,表明我国这些非核设施影响地区的129I处于当今全球环境的本底放射性沉降水平.     

高效液相色谱/电感耦合等离子体质谱联用技术用于元素形态分析的研究进展

介绍了高效液相色谱与电感耦合等离子体质谱（HPLC－ICP－MS）联用技术在环境、材料和生命科学样品的元素形态分析中的研究进展，着重介绍该联用方法的接口技术及几种与ICP－MS联用的主要色谱类型，阐述了几种样品预处理方法，并对样品引入系统、复杂基体分离和元素形态定量和结构分析等联用技术在元素形态分析中所面临的问题进行讨论。     

Determination of trace elements in crude oils and organic materials extracted from oil-forming source rocks in China by INAA

A combination of Soxhlet extraction, column chromatography and INAA with GC and GC-MS was used in this work for the study of the abundance patterns of 36 trace elements and their correlation in nearly 100 samples of crude oil and organic materials extracted from oil-forming source rocks from 10 main Chinese oilfields. The low V/Ni ratios of 0.01 to 0.3 state the oil-forming continent environment. The geochemical significance hinted from other trace element abundances is also briefly discussed.     

Dose assessment around the Yatagan coal-fired power plant due to gross alpha-radioactivity levels in flying ash

The gross alpha-radioactivity levels in ash wastes from the Yatagan coal-fired power plant have been measured, and radiation dose calculations have been carried out, by the computer code CAP88-PC, around the plant environment by using the maximum measured gross alpha-activity in the flying ash samples as a radioactive source. The results obtained from the calculations are under the dose limits of International Commission of Radiation Protection (ICRP) and have not any risk for public health around the plant environment.     

Uranium and plutonium containing particles in a sea sediment sample from Thule, Greenland

Particles composed of radioactive materials and probably originating from US nuclear weapons were identified in sea sediment samples collected from Thule, Greenland, in 1997. The weapons were destroyed close to the Thule Air Base in 1968 in an aeroplane crash, which dispersed radioactive materials in the environment. The presence of particulate radioactive materials in the sediment samples was revealed by combining gamma-spectrometry and autoradiography. Isolation and separation of a radioactive particle from a bulk sample were performed using autoradiography, phosphor plate imaging and scanning electron microscopy. Using X-ray microanalysis as well as alpha and beta activity analysis, U and weapons-grade Pu were detected in the granular, brittle particle.     

Correlation of natural and artificial radionuclides in soils with pedological,climatological and geographic parameters

Various types of soil samples were collected in the southern part of Brazil, with depth intervals of 5 cm, down to 50 cm, using a specially designed sampler. Pedological analysis of these soils were performed. Nuclear activities of¹³⁷Cs (expressed in Bq m^–2) and radioactive natural element (²²⁶Ra,²²⁸Ra and⁴⁰K) concentrations were determined by low background gamma-ray spectrometry.¹³⁷Cs concentrations were correlated with radioactive natural element concentrations and pedological, climatological and geographic parameters related to the soil samples collected.     

Chemical studies of the Mundrabilla iron meteorite by neutron activation

We report on trace and minor element contents in the large 6.1 ton mass of the Mundrabilla iron meteorite as determined by non-destructive and radiochemical neutron activation analysis. Mundrabilla is a medium octahedrite and is classified as a anomalous member of group IA. Its structure is very exceptional, consisting of about 75% ironnickel and around 25% sulfide inclusions, mainly troilite (FeS). Most samples for analysis were taken as drill samples, and metal and sulfide portions were carefully separated to avoid cross contamination. In pure metal samples, the elements Mn, Co, Ni, Cu, Ga, Ge, As, Ir and Au are remarkably uniformly distributed over large areas of the meteorite. Most elements analyzed in the different sulfide samples exhibit a larger range in concentration, except Se and Cr which are very uniform and strongly chalcophile. Implications of element abundances are discussed.     

Design for an asymmetrical cyclic neutron activation process for determining fluorite grade in fluorspar concentrate

Conventional neutron activation procedures rely on cycles of equal length to test samples of fluorspar concentrate. This paper proposes a new procedure using “asymmetrical” cycles, in which the duration of the first cycle is different from that of the subsequent activation cycles, which are conducted once the radioactive concentration of the element of interest has been partly reduced through radioactive decay. A comparison is made between the two procedures, and the advantages of the new technique over the conventional one are examined.     

Activation analysis of rare-earth elements in opium and cannabis samples

Rare earth concentrations in 65 Opium, Cannabis and Cannabis resin samples seized from various parts of world were determined by destructive NAA. Great variations in absolute element concentrations, but only small significant differences of rare earth concentration ratios were found, indicating inconsiderable biogeochemical fractionation. The mean values of these ratios correspond with the relative abundances of the rare earths in the upper continental earth's crust.