共查询到20条相似文献,搜索用时 46 毫秒
1.
Peter DULSKI 《Geostandards and Geoanalytical Research》1992,16(2):325-332
Analytical data on samples FeR-1, FeR-2, FeR-3 and FeR-4 obtained by instrumental neutron activation analysis and by inductively coupled plasma mass spectrometry are presented. The applied methods are described, and the analytical problems associated with their use are discussed. The accuracy of the two methods is demonstrated by comparing the results with the recommended values of the iron formation reference sample, IF-G. For the four FeR samples a set of values summarizing all data obtained by the two analytical methods is also given. 相似文献
2.
Skarns of the Kordonnoe tungsten deposit located in the Malinovsky ore cluster in Primorsky krai were scrutinized based on the study of core samples. The mineral types of the skarns and the near-skarn rocks have been distinguished and briefly described and their ore specialization has been established. The typomorphic peculiarities of the rock-forming minerals were compared with those of the reference objects of the region. The problems of skarn genesis are discussed. 相似文献
3.
简易气量法测试土壤过氧化氢酶活性的研究 总被引:1,自引:0,他引:1
通过比较现有的过氧化氢酶活性测试方法发现,气量法尽管是最简便的方法,但存在很多问题,不利于广泛使用,而简易气量法则解决了前人气量法存在的问题.利用该方法对同一个土壤样品进行的9次重复实验结果表明,格拉布斯(Grubbs)检验无剔除数据,标准偏差为1.61,变异系数为0.17,显示该方法简单、快捷、重现性好,精密度高;对20个土壤样本进行初始反应速度、最大反应速度、米氏常数测试的结果显示,它们之间的相关性显著,c(H2O2)=0.741 mol/L为最佳测试过氧化氢酶活性的底物浓度.最后对简易气量法存在的问题进行了分析. 相似文献
4.
SAVNTE BJÖRCK SÖREN HÅKANSSON 《Boreas: An International Journal of Quaternary Research》1982,11(2):141-150
Altogether 62 radiocarbon dates from 17 pollen diagrams (16 sites) of Late Weichselian lake sediments in S Sweden have been determined to establish the chronostratigraphic sequence as defined by the pollen stratigraphy. This method of controlling the dates and the validity of the assumed synchronous Nordic climatostratigraphy are discussed. Most of the dates sufer from age erors, mainly caused by contamination by redeposited organic material. The effect of this source of error increases with decreasing percent of organic carbon in the deated samples. The significance of these problems for the Late Weichselian chronostratigraphic subdivision as well as ways of solving them are discussed. 相似文献
5.
In 1978, seven uranium ore reference samples were prepared by the Bureau of Uranium Geology (China). The processing of these samples, prepared in the range of 220–370 kg, is briefly presented along with their general chemical composition. Analytical procedures employed for the determination of U, Th and Ra are briefly discussed. Recommended values are proposed for U, Th and Ra in the seven reference samples. 相似文献
6.
7.
择优取向在粘土矿物X射线衍射定量分析中的应用研究 总被引:3,自引:0,他引:3
采用K值法,以蛇纹石或白云母矿为参比物,利用晶面的择优取向,对蒙脱石粘土、海泡石粘土、凹凸棒石粘土和高岭石粘土进行X射线物相定量分析,取得满意结果。同时总结出这些粘土矿物的K值,并在此基础上讨论与择优取向相关的问题。 相似文献
8.
依据12126个样品求出我国17个地洼区的花岗岩类平均化学成分,并运用富集元素组合的分析方法,讨论各地洼区花岗岩类的大地构造岩石化学类型和区域岩石化学特征。不但指出其区域差异性,而且还指出其若干区域分布规律性,以及有关南北地洼区的特性问题。 相似文献
9.
Method peculiarities of multielemental analysis of rocks with inductively-coupled plasma mass spectrometry 总被引:1,自引:0,他引:1
Ya. V. Bychkova M. Yu. Sinitsyn D. B. Petrenko I. Yu. Nikolaeva I. A. Bugaev A. Yu. Bychkov 《Moscow University Geology Bulletin》2017,72(1):56-62
Decomposition of samples with a poorly soluble complex matrix for the analysis of the trace-element composition with high-resolution inductively-coupled plasma mass spectrometry was designed and tested. Analytical and method problems of the selection and preparation of samples are described and their solutions are proposed. The correctness of sample preparation was verified using analysis of standard rock samples. 相似文献
10.
11.
地质调查样品中有机氯农药分析存在的困难和解决方法 总被引:2,自引:2,他引:0
9种有机氯农药(六氯苯、α-HCH、β-HCH、γ-HCH、δ-HCH、p,p′-DDE、p,p′-DDD、o,p′-DDT和p,p′-DDT)是国土资源地质大调查项目中水和土壤样品必测的有机污染物。有机氯农药自身结构和性质的特殊性以及地质调查样品的差异性,在采用气相色谱电子捕获检测器(GC-ECD)分析有机氯农药过程中仍然存在许多困难。文章结合大量地质调查样品中有机氯农药分析的实践经验,从溶剂与待测物响应值的关系、基质效应的表现、样品前处理以及仪器日常维护四个方面,介绍了针对不同样品和分析要求正确选择进样溶剂、判断和解决基质效应,并通过良好的仪器日常维护习惯确保地质调查样品中有机氯农药检测灵敏度达到要求。 相似文献
12.
13.
广东韶关红粘土特性研究 总被引:2,自引:0,他引:2
本文通过微观分析与宏观试验,对广东韶关红粘土的物化特性以及改变物化特性对土的力学特性的影响进行了研究。虽然试样取自韶关,但所探讨的问题涉及到各地红粘土的共性,故具有普遍意义。 相似文献
14.
15.
介绍了在低真空模式下扫描电子显微镜配装X射线能量色散谱仪检测宝玉石的原理与方法。对比与评估了宝玉石样品的X射线能量色散谱仪的无标样定量分析数据与其标准数据,讨论了扫描电子显微镜配装X射线能量色散谱仪在宝玉石检测分析中存在的问题。通过与其它宝玉石检测分析仪器如X射线荧光分析仪、X射线粉末衍射仪、傅里叶变换红外光谱仪及激光拉曼光谱仪比较后认为,扫描电子显微镜配装X射线能量色散谱仪对宝玉石无损分析鉴定是最方便、有效的手段之一。 相似文献
16.
全氟类有机污染物的污染状况及其生态毒理研究进展 总被引:4,自引:0,他引:4
全氟类有机化合物(Perfluorinated compounds,PFCs)广泛应用于工业和民用产品,该类化合物具有高能量的C-F共价键,难以被水解、光解、微生物降解及动物体代谢,具有持久性、生物累积性、毒性以及长距离迁移等特性,是一类新型持久性有机污染物.目前,从世界各地采集的环境样品、野生动物血清、组织样品以及人类体内都检测到了多种PFCs.该类污染物对生态环境和人体健康带来的影响受到全社会的普遍关注,已成为环境科学和生态毒理学研究的热点课题之一.本文综述了全氟类化合物在各类环境介质中的分布、在生物体内的累积、在生物体内的转化与代谢过程及其毒理学效应,并对PFCs的毒性作用机制进行初步分析,对目前存在的问题及今后的研究方向进行了讨论和展望,以期为该类化合物的环境污染及风险评估提供相应参考. 相似文献
17.
K. Randle 《Chemical Geology》1974,13(4):237-256
A number of problems associated with the geochemical application of instrumental neutron activation analysis are discussed. Particular emphasis is placed on the problems of preparing and using multi-element standard solutions and/or those associated with the accurate computer reduction of γ-spectral data. It is concluded that accurately and extensively analysed rocks and minerals best fulfil the requirements for multi-element standards in this type of analysis.In the second part of the paper instrumental neutron activation analysis data are presented for 26 international reference samples including 4 of the less well-analysed U.S.G.S. standard rocks. Some limited geochemical interpretations of the data are presented. 相似文献
18.
大陆地壳演化时间维的确定及存在问题 总被引:3,自引:0,他引:3
在大陆地壳演化研究中,时间维的确定具有十分重要的意义。讨论了应用最广泛的U-Pb法和等时线法的适用性及存在的问题。指出对U-Pb年龄研究过程中需要加强成因矿物学研究,而对等时线年龄必须根据基本原理对等时线进行合理性判别,以决定样品的取舍。以Sm-Nd法为代表,讨论了Sm-Nd等时线年龄和U-Pb年龄所代表的地质内涵。最后对新疆近年来同位素年代学所取得的进展做了简要评述。 相似文献
19.
20.
C/S模式下Sybase程序健壮性的讨论 总被引:3,自引:3,他引:0
作者在本文中针对C/S开发模式下,由于网络不稳定因素易造成客户端与服务器的连接断线而影响应用系统的运行效率,提出了相应的解决方案。这些方案,能很好地改善程序的健壮性并显著提高系统效率。大量的实验测试和项目实例证明,这些方案是稳定可靠、切实可行的。 相似文献