新型的氩提取系统

氩的稀释技术早在五十年代开始,到了六十年代,由于采取了超高真空技术和质谱静操态操作,使氩的测试水平大大提高,但到六十年代中期,国内外氩提取系统没有更多的发展,只是近些年来才有价格昂贵的全金属商品氩提取系统。虽然形式不同,繁简不一,但有共同的特点是熔样系统与纯化系统分开。     

Sludge Ash Reference Sample

A suldge ash reference sample has been prepared. It has been analyzed by twenty-one independent laboratories. Information is presented on the number of analysts reporting each element, and the various instrumental methods used. Results are reported for twenty-six elemental determinations. Recommended elemental composition of the sample is given for twenty-one elements.     

ICP固体粉末法光谱定量测定岩石中微量锆、铌、钇、■等十五项元素

本文在基础上介绍一种固体粉末进样装置及测定方法。其特点是。设计了射流管进样器,利用射流的卷吸扩展作用使粉末样品经气动雾化而被卷吸直接引入等离子炬,通过将样品粒度加细的途径解决了粉末粒子在炬中充分蒸发的问题,提高了难蒸发元素的准确度。 分析时,样品与缓冲剂按比例混匀,取混合样一次摄谱(所需纯样品量为3.33毫克),可同时测定锆、铌、镧、钇、钡、锶、铬、镍、钒、硼、钴、钛、铜、铅、铍十五项元素,检出限除钡、锶、钛、硼略高,其它元素均为ppm级。     

含金地质样品的均匀性及代表性研究

近年来对金矿石的制样研究认为，金测定精密度和准确度较低的主要原因是样品加工中存在的问题。因此，研究不同类型的金矿石制样，改进加工流程，是保证金分析质量的前提．通过对甘肃李子园、小沟里、三洋坝等秦岭山脉区的粗颗粒性金矿石的制样研究，制定出了比较合理的制样流程。     

湿法消解和微波消解微量滴定法测定铜试样中铜的含量

采用微量滴定法测定铜盐中铜的含量，结果表明，方法分析速度快，试剂用量少，与常量滴定法无显著性差异。采用湿法消解、微波消解微量滴定法同时测定铜合金和铜精矿中铜的含量，结果表明，对铜合金的测定，湿法消解和微波消解两者无显著性差异；而对于铜精矿的测定，样品的溶解效果微波消解方法明显优于湿法消解。     

水泥土(砼)抗压试件尺寸表面约束对强度的影响

推导了圆柱体试件和长（立）方体试件,分别在不同表面摩擦力和不同高宽（径）比下基于双剪屈服准则下抗压强度的理论计算公式,并与实验结果比较所得结果与实验结果甚为吻合。其理论计算与实验结果都说明,试件尺寸的不同与表面抹油与否对水泥土抗压强度均有一定的影响。其高宽（径）越大,其强度越低且越趋于一定值。试件上下表面不摸油其抗压强度略高抹油情况。     

有关土壤汞量测量的几点思考与探讨研究

对于土壤汞量测量工作中存在的一些疑问,如土壤吸附汞测量的定义与其热释温度是否对应,土壤样品研磨对测量结果有何影响,土壤吸附汞测量相对于全量汞测量的应用前景等等,笔者尝试进行实验性探讨和个案分析,获得以下几点认识:①原子态汞在表生环境中,其衍生化合物包含硫化汞,且占有相当大比例;②辰砂及一些无定形态汞化合物颗粒(如非晶态的硫化汞等)的分布状态是影响测量结果的主要因素;③样品研磨对测量结果的影响要远大于滞留在样品中的原子态汞。基于这种认识,建议性提出土壤样品加工方法及测试要求,并就实验中的一些现象及研究需要,提出“似颗粒效应“、“当量氯化汞“和“土壤泛低温汞测量“等概念,为进一步完善土壤汞量测量方法技术提供了一种新的见解和思路。     

A spectrophotometric method for the determination of rhenium in geologic materials

Existing methods for the chemical determination of rhenium have been modified and adapted for the analysis of rock, sediment, water, brine, and mineral concentrates.Little restriction is placed on sample size, but usually between 0.1 g and 100 g of solid sample is used which contains between 1 and 200 μg of rhenium giving a detection limit of 10 p.p.b. in the sample. Several liters of water sample may be used giving a detection limit of less than 1 p.p.b.The spectrophotometric method concentrates and isolates the rhenium from the sample by using carbon adsorption and solvent extraction.     

鄂尔多斯盆地北缘地球化学大数据样本优选分析

众所周知,地球化学数据携带有众多地质噪音,这些噪音严重影响地球化学数据信息的客观性与可靠性;对于地球化学大数据融合分析而言,确定样品的有效性及变量优选是滤除地质噪音、建立最优样本集合的必要性工作,因而在地球化学大数据处理分析前需首先进行大样本优选,从而更加客观、真实的揭示地球化学大数据信息及相关地质意义。本文以鄂尔多斯盆地北缘1∶20万地球化学土壤测量数据为例,考虑元素之间的地球化学亲和力与组合匹配关系,建立非线性大样本优选模型。具体做法是基于优选后的样品矩阵,将39个元素变量分解成若干独立因子向量,将最优独立因子向量作为元素组合,其向量各分量作为元素变量的权重,依权重大小进行变量优选;优选后的样本集合可以作为该区地球化学数据分析与信息识别的有效地学信息集合,运用这种集合可以有效开展鄂尔多斯盆地外围铀地球化学分析,并为盆地铀资源预测奠定基础。     

The Preparation and Certification of Two Samples of Chromium Ore

The preparation of two chromium ores as reference materials is described and the procedures used in the measurement of the homogeneity of the samples are outlined. Statistical analysis of the data submitted by 32 laboratories that resulted in the certification of the samples is presented. Certified values have been assigned for 11 constituents in the one sample and for 10 in the other sample. Provisional values have been assigned for FeO in both samples and CaO in one of the samples.     

Artifacts produced by chemical processing of samples for micropalaeontology and organic geochemistry — a note of caution

For the preparation of insoluble carbonaceous residues for micropalaeontological work, HCl/HF acid attack is normally used to demineralise the sample from its matrix. During this sample preparation, numerous synthetic insoluble fluorides or fluoro-complexes are formed. Their identification by X-ray diffraction becomes cumbersome. A chart has been constructed to simplify their identification. During the same sample preparation, if, for example, the sample is a pyritic shale, possible artifacts are produced which could be misinterpreted as microfossils. In the present work, the artifact that was formed had a framboid-like morphology. Step-by-step observations are recorded by applying the techniques of scanning electron microscopy and electron probe microanalysis.     

FLUORINE ABUNDANCES OF TWENTY NINE GEOLOGICAL AND OTHER REFERENCE SAMPLES USING FAST-NEUTRON ACTIVATION ANALYSIS

The fluorine content in twenty-nine reference samples of geological interest has been determined using a well tried and tested method which has been previously reported. The analytical method uses fast neutron activation involving the reaction ¹⁹F(n,a)¹⁶N and gamma spectrometry. Interferences have been found to be negligible for the experimental conditions used. The method involves minimal sample preparation, is rapid and can easily measure concentrations down to 5 parts per million in a 5 g sample.     

两个古铜辉石样品的G.P区研究

在两个斜方辉石样品中观察到G.P.区亚稳相。内蒙古暗色辉长岩古铜辉石成分是En_(77)Fs_(18·6)Wo_(4·4),其高分辨象显示了密集的单层G.P.区;玄武岩中变辉长岩包体古铜辉石成分是En_(72·2)Fs_(25·7)Wo_(2·1),具双层G.P.区。该包体与具多层G.P.区的月岩橄长岩相似,后期冷却极快。在地体火成岩体结晶和冷却过程中易出现单层G.P.区,而岩体的大小,冷却的快慢可能影响G.P.区的密度。对N-14样品不同放大倍数的高分辨象G.P.区线密度和面密度的统计值同样具代表性。文中设想了G.P.区出溶的假二元系相图。     

National-Scale Geochemical Mapping Projects in China

Regional, national and global scale geochemical mapping projects have been carried out in China since the late 1970s, due to the development of cost‐effective, low detection limit analytical methods. These projects have provided a huge mass of high‐quality, informative and comparable data for mineral resource exploration and are now making contributions to environmental assessment. In this paper, four national‐scale geochemical mapping projects are described. (1) The Regional Geochemistry‐National Reconnaissance Project (RGNR project), which is China's largest national geochemical mapping project, has covered 6 million km² of upland regions since 1978. Generally, stream sediment samples were collected at a density of 1/km² and four samples were composited into one sample and analysed for thirty‐nine elements. (2) The deep‐penetrating geochemical mapping project (DEEPMAP Project) has been conducted since 1994 in covered terrains, including sedimentary basins, at a density of 1 sample per 100 km² with thirty to seventy elements determined per sample. In the past 10 years, an area of approximately 800 000 km² has been covered and this project has played an important role in finding sandstone‐type uranium deposits in basins. (3) The seventy‐six geochemical element mapping project (76 GEM project) has been carried out since 1999 and involved the collection of stream sediment samples from the RGNR project targets which were analysed for seventy‐six elements. Samples from each 1:50 000 map sheet were composited into one analytical sample (approximately one composite sample per 400 km²). Approximately 1 million km² have been surveyed to date. (4) The multi‐purpose eco‐geochemical mapping project has been conducted since 1999 in Quaternary plain areas for environmental and agricultural applications. Surface soils (depths from 0–20 cm) were collected at a density of one sample per km², and four samples were composited into one for analysis. Deep soils (from a depth of 150 to 200 cm) were collected at a density of one sample per 4 km² and four samples were composited into one analytical sample. All the composite samples were analysed for fifty‐four elements.     

固体粉末稳态法发射光谱分析新型进样器的研制及应用

介绍了一种新型固体粉末进样装置,它由样品气溶胶喷射系统、高频火花雾化控制电路等部分构成,并阐述了装置的工作原理和结构设计。通过对化探样品中痕量B、Pb、Sn和Ag等元素的对比测定试验表明,利用新研制的进样装置代替原来的双高频火花雾化进样器,可使单样平均残留率由原先的26.7%降到0.79%;对比试验表明,方法的精密度(RSD,n=12)由原先的4.31%～6.81%提高到2.37%～3.43%。     

Modal analysis by point‐counter — The choice of sample area∗

Point‐counter analyses include two errors, determined separately by count length and by sample area. The counting error has been studied by Chayes, and his latest results admit an estimate also of the sampling error. It is postulated that the sample size and the rock coarseness do not affect this error independently; instead, they combine to determine the effective number of grainsections sampled, and this in turn controls the sampling error. The estimate of the sampling error is compared with that for the counting error in selecting the best sample sizes and count lengths for projected work.     

基于DEM数据的古沉积面的重建方法——以青藏高原东北缘青海贵德盆地为例

广泛使用的数字高程模型（DEM）数据使得古沉积面的恢复成为可能。以青藏高原东北缘的青海贵德盆地为例,分析对比了前人获取代表古沉积面地表露头样本数据的几种方法．提出了插值样本应选择露头中代表原始沉积地层的顶面点的优选方法,并提取了更新统地表露头顶面点的样本数据。通过分析样本的特征、比较插值的结果,选择了自然邻点法进行插值预测,重建了贵德盆地更新统的古沉积面。正确样本,最的提取加上合适插值算法的选择．优化了重建的古沉积面。     

基于DEM数据的古沉积面的重建方法 ——以青藏高原东北缘青海贵德盆地为例

广泛使用的数字高程模型（DEM）数据使得古沉积面的恢复成为可能。以青藏高原东北缘的青海贵德盆地为例,分析对比了前人获取代表古沉积面地表露头样本数据的几种方法．提出了插值样本应选择露头中代表原始沉积地层的顶面点的优选方法,并提取了更新统地表露头顶面点的样本数据。通过分析样本的特征、比较插值的结果,选择了自然邻点法进行插值预测,重建了贵德盆地更新统的古沉积面。正确样本,最的提取加上合适插值算法的选择．优化了重建的古沉积面。     

Dispersal of tungsten in glacial drift and humus in Bergslagen, southern central Sweden

Since the late part of the 19th century prospecting for W in the western world has been based mainly on the mechanical concentration of heavy minerals in sediments (panning), followed by visual and chemical analyses of the heavy-mineral fraction. Since the early 1970's, W prospecting in Sweden has been based on the use of heavy-mineral concentrates from till.In tests performed in a scheelite-mineralized area in the Bergslagen area of central Sweden, samples from the A- and C-horizon of the podzolic profile have been collected along grid lines across the ore as well as down-ice along the direction of final glacial transport from the ore. The purpose of the study was to test which sample types should be used in geochemical prospecting for W in the region.The results show that all the sample types studied can be used in geochemical prospecting for W in southern central Sweden. The heavy-mineral concentrate of till is primarily recommended for use at a regional and local scale. Humus is given the lowest priority of the sample types studied because of the poor analytical reproducibility for some samples with high values of W.     

X射线荧光光谱熔融制样法测定钛铁矿中主次量组分

采用熔融玻璃片法制样，X射线荧光光谱法测定钛铁矿中Fe、Ti、Si、Al、Ca、Mg、Mn、P、S、V和Cr等11种主次量组分。探讨了熔融钛铁矿的有效熔剂，认为Li2B4O7和Li2CO3混合熔剂效果好。方法用于钒钛磁铁矿等国家一级标准物质的测定，结果与标准值相符，对主、次量组分方法精密度（RSD，n=10）为0．20％～9．10％。