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51.
峡东莲沱组与湖南板溪群五强溪组或漠滨组之间的关系素有争议,湖南省地矿局区调队将峡东莲沱组与湖南五强溪组对比是值得商榷的问题。本文提出峡东莲沱组沉积时代应晚于长安亚冰期,应与富禄间冰期早期地层即石门县杨家坪渫水河组,湘北、湘西莲沱组及湘中江口组含铁砂岩段相当的认识。 相似文献
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文章对几种分离测量硅酸锰的方法进行了对比。指出硅酸锰测定失真的缘由。选择了浸取分离伴生铁矿物的浸取剂及浸取分离条件。 相似文献
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本文利用引文分析方法,对代表中、美、日地震学研究水平的《地震学报》、《美国地震学会通报》和《地震》三个核心期刊1988-1990年期间的410篇论文所附的7095篇引文的引文量、引用学科、引文来源和语种、自引、互引及引文年代进行了统计分析;此外,还探讨了中外地震学文献交流的现状和影响因素,以期对掌握地震学文献交流的规律和特征、文献的利用和管理及促进中外地震学文献的交流提供有益的启示和参考。 相似文献
55.
Six North American bituminous coals (four Carboniferous and two Cretaceous) and eight maceral concentrates from Carboniferous British seams have been heated with tetralin and hydrogen to 400°C. The hexane-soluble parts of the products were separated by column chromatography and the fractions were then analyzed by gas chromatography/mass spectrometry. In all cases the aromatic hydrocarbon fraction was a very complex mixture containing a number of alkylated biphenyls, diphenylmethanes and -ethanes, and polycyclic compounds. However single ioncchromatography (m/z = 142) showed that, in addition to these, the products from five of the six American coals contained homologous series of long chain n-alkylnapththalenes with alkyl groups extending to C16. In other fractions from the American coals, homologous series of n-alkylfurans and alkylphenols were found to be major components, as also were many alkylcyclohexenones related to isophorone. Extensive homologous series of n-alkyl aromatics were not detected in products from any of six vitrinites from British seams, though series of n- and iso-alkylphenols were found in the products from two sporinite concentrates. A number of polycyclic ketones apparently related to sterols were found in the products from the British vitrinites but not from any American coals. Reasons for what appear to be systematic structural differences between the American and British coals are discussed. Differences in stratigraphy are noted and it seems not impossible that differences in source vegetation are significant. 相似文献
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Allocating local groundwater monitoring stations for South Korea using an analytic hierarchy process 总被引:1,自引:1,他引:1
Jeong-Woo Kim Jin-Yong Lee Myeong-Jae Yi Gyoo-Bum Kim Jong-Ho Won Kang-Kun Lee 《Hydrogeology Journal》2007,15(3):615-632
A national groundwater-monitoring network consisting of 320 stations has been operated by the Ministry of Construction and Transportation and the Korea Water Resources Corporation since 1995. The network was established as a result of the Groundwater Act of Korea, and a supplementary local groundwater monitoring network containing 10,000 stations will be established throughout the country by the year 2011. A method of allocating stations and organizing the local monitoring network has been developed, based on the analytic hierarchy process (AHP), using pairwise comparison. Several evaluation criteria were selected for determining the required number of the monitoring stations at specific local districts. Weights of the selected criteria were assigned by the pairwise comparison, reflecting hydrogeological conditions and supported by pertinent questions to 93 groundwater experts. To evaluate appropriateness of this method, an example city, Jeonju, was selected where groundwater levels were monitored; seven stations were determined as to be required for the supplementary groundwater-monitoring network. The study demonstrated the usefulness of the AHP. The concepts of the development and the structure of the AHP model can be applied to site or well selections within a particular district. 相似文献
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几种Q矢量的比较 总被引:12,自引:1,他引:12
利用 1 991 - 0 7- 0 5T2 0— 0 6T2 0一次江淮梅雨锋暴雨过程实况资料 ,结合地面降水分布 ,从定性 (矢量场 ,即 Q)、定量 (散度场 ,即 2 · Q)的角度细致、具体地比较分析了准地转 Q矢量、半地转 Q矢量、非地转 Q矢量及湿 Q矢量的诊断特性。结果表明 :半地转 Q矢量诊断能力优越于准地转 Q矢量。非地转 Q矢量、湿 Q矢量诊断能力明显优越于准地转 Q矢量、半地转 Q矢量。准地转 Q矢量诊断能力最差 ;从定性的角度分析 ,非地转 Q矢量与湿 Q矢量诊断能力相差不大。但进一步定量分析发现 ,在整个梅雨锋暴雨过程中 ,湿 Q矢量的诊断能力大于其他 Q矢量 ;70 0 h Pa高度上各 Q矢量的矢量、散度辐合区较其在 850 h Pa和 50 0 h Pa上对降水反映更好 ,尤其是70 0 h Pa湿 Q矢量散度辐合区与降水区有非常好的对应关系。 相似文献
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改进了游离二氧化硅(fSiO2)测定中试样的分解方法,采用硫-磷混酸替代单独使用磷酸分解试样,防止了焦磷酸盐的形成,同时,氟硼酸对fSiO2的溶解率符合测定要求。改进的方法用于标准物质中fSiO2的测定,结果与标准值或磷酸溶矿重量法相符。对于ω(fSiO2)=3.26%的标样10次测定的RSD为2.4%。 相似文献