共查询到20条相似文献，搜索用时 46 毫秒
1.
报道了以NH4H2PO4为基体改进剂，采用悬浮体制样石墨炉原子吸收光谱法直接测定琥珀中微量铅的方法。试验了影响测定的主要因素。在优化实验条件下。方法的检出限为0．038μg／g，Pb的质量浓度为0～80μg／L时，工作曲线线性关系良好。对于ω(Pb)=5．71μg／g样品的测定，相对标准偏差(RSD，n=5)为6．83％。 相似文献
2.
3.
X射线荧光光谱法同时测定煤中砷硫磷氯 总被引：1，自引：0，他引：1
采用人工混配有限煤炭标准样品粉末直接压片制样，X射线荧光光谱仪同时测量煤中的砷、硫、磷、氯。优化了样品粒度、样品量、助磨剂、制样压力和保压时间等实验条件，用可变α系数法进行基体校正。方法测定范围为As0．0015％-0．0051％、S0．21％-1．44％、P0．003％～0．096％、C10．01％-0．11％；检出限为As 1．2μg／g、S22μg／g、P2．1μg／g、C12．0μg／g。与标准方法对照，结果基本一致。方法快速、简便，满足了煤炭检验需要。 相似文献
4.
多目标地球化学调查土壤样品中氮和碳的快速测定 总被引：2，自引：1，他引：2
详细研究了元素分析仪的工作条件，建立了直接固体进样同时测定多目标地球化学调查土壤样苎支氮、碳的方法。方法简便、快速，检出限为氮14．5μg／g、碳0．013％。经土壤国家一级标准物质分析验证，测定值与标准值相符，精密度（RSD，n=12）为氮1．49％-3．27％、碳0.64％～3.63％。 相似文献
5.
悬浮液进样-氢化物发生原子荧光光谱法测定土壤中痕量砷锑硒 总被引：5，自引：2，他引：5
在原子荧光光谱法传统样品前处理的基础上，提出了悬浮液进样技术。用琼脂作为悬浮剂，水溶液作为校正曲线，对土壤标准样品和实际样品进行测定，结果令人满意，并且省去了冗长的样品化学前处理过程。检出限分别为砷0．33μg／L、锑0．13μg／L、硒0．06μg／L；相对标准偏差分别为：砷3．92％～6．32％、锑1．76％～3．11％、硒3．08％～5．54％；回收率分别为砷98．7％～105．7％、锑99．5％-103．3％和硒94．6％-107．2％。国家一级标准物质的测定结果与标准值相符，实际样品的测定值与传统消化法相比较，结果基本一致。 相似文献
6.
高效阴离子交换色谱-紫外检测器联用测定海水中碘 总被引：1，自引：0，他引：1
建立了在碱性体系中采用高效阴离子交换色谱和紫外检测器联用测定海水中碘离子的分析方法。以63mmol／L NaOH为淋洗液，利用IonPac AS16型强亲水性阴离子交换分离柱．碘离子在8．3min洗脱，经抑制器后进入紫外检测器在波长226nm处检测。方法的检出限为0．05μg／L（进样量500μL，3倍信噪比），标准曲线的线性范围为1～2000μg／L（r=0．9995）。20μg／L碘离子标准溶液9次连续进样的相对标准偏差为1．85％。方法已成功地应用于海水中碘离子的测定，1μg／L碘离子的加标回收率为98％～105％。 相似文献
7.
用金属铝与液态溴发生反应生成的AlBr3溶于甲醇、而Al2O3在无水条件下不与液态溴发生反应的不同化学行为特性，实现了Al与Al2O3的分离，采用铝试剂光度法测定铝锭中的微量AAl2O3。结果表明，在pH4．4的NaAc—HCI缓冲溶液中，铝与铝试剂形成的配合物在530nm处有最大吸收。Al2O3含量在0～3．0mg／L遵循比尔定律。方法检出限为0．005mg／L。建立的方法用于实际铝锭样品中Al2O3的测定，精密度（RSD，n=5）为3．50％～14．3％，加标回收率为98．9％～99、7％。 相似文献
8.
发射光谱法测定勘查地球化学样品中银硼锡钼铅 总被引：21，自引：13，他引：21
以K2S2O7、NaF、Al2O3和炭粉为缓冲剂，Ge为内标，电弧发射光谱法测定勘查地球化学样品中Ag、B、Sn、Mo、Pb。方法检出限为Ag0．013μg／g、B0．83μg/g、Sn0．23μg／g、Mo0．073μg/g、Pb0．37μg／g。方法精密度（RSD，n=12）为Ag4．2％～11．3％、B3．2％～6．5％、Sn2．6％～7．1％、Mo2．9％～6．3％、Pb1．57％～5．18％。测定了国家一级地球化学标准物质，结果与标准值相符。 相似文献
9.
原子荧光光谱法直接测定铜矿中的硒 总被引：6，自引：5，他引：6
采用硫脲抑制铜的干扰，不经分离富集原子荧光光谱法直接测定铜矿中的Se。方法的检出限为0．02μg/g。Se浓度在0～80μg／L与荧光强度呈线性关系。用铜矿石国家一级标准物质GBW 07233(ωSe为5．1μg／g)和GBW 07234(ωSe为0.89μg／g)进行精密度试验，RSD(n=12)为3.44％、8.06％。加标准回收试验结果，Se的回收率为93．2％～104、6％。经铜矿石国家标准物质验证，测定结果与标准值相符，方法适用于铜矿中0～8．0μg／g Se的测定。 相似文献
10.
11.
Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco. 相似文献
12.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
13.
The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species. 相似文献
14.
Muriel Rocher Stéphane Baize Stéphane Jaillet Edward Marc Cushing Yannick Lozac&#x;h Francis Lemeille 《Comptes Rendus Geoscience》2003,335(8):701-708
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003). 相似文献
15.
正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level 相似文献
16.
正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7), 相似文献
17.
18.
正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci- 相似文献
19.
正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli- 相似文献
20.
正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.) 相似文献