氢化物发生—原子荧光光谱法测定煤样中的硒   总被引：6，自引：2，他引：6  

梁立娜  何滨等 《岩矿测试》2001,20(1):31-33

采用氢化物发生原子荧光光谱法测定了煤样中的总Se。煤样选用高压闷罐强酸消解的方法进行处理，所得消解液经6mol/L HCl将Se（Ⅵ）还原为Se（Ⅳ），然后进行测定。标准工作曲线的线性范围为0－400μg/L Se，检测限为0.4μg/L Se。用标准参考物质煤飞灰对方法进行了验证，所得总Se含量与标准值相符，对ω为10^-6级Se的4次测定，RSD≤4.5％。  相似文献   

Sm—Nd and Zircon U—Pb Isotopic Constraints on the Age of Formation of the Precambrian Crust in Southeast China   总被引：1，自引：0，他引：1  

李献华  赵振华等 《中国地球化学学报》1992,11(2):111-120

Nd model ages(TDM) of the Pre-Mesozoic crustal rock samples from Southeast China range from 1.2 to 3.5Ga.Two age peaks of 1.4Ga and 1.8 Ga are observed in the histogram of TDM model ages.Available U-Pb zircon inheritance ages are concentrated around 1.2-1.4Ga,1.8Ga and 2.5Ga,respectively.The combined use of Sm-Nd and U-Pb zircon inheritance ages suggests that the formation of the Precambrian curst is of episodic character.The oldest crustal nucleus may have been formed during the Late Archean(2.5Ga or older?).A rapid production of the crust took place 1.8 Ga ago,consistent with the global crust formation event at 1.7-1.9Ga.Another important episode of the addition of juvenile crustal material from the mantle in Southeast China took place 1.2-1.4Ga ago,during which the pre-existing crust was strongly reworked and/or remelted.  相似文献   

论当前我国北西部铀矿勘查关键技术   总被引：1，自引：1，他引：1  

赵致和  孙圭 《铀矿地质》1995,11(2):65-69

本文提出当前我国北西部铀矿勘查两项关键技术──中国北西部寻找大型超大型可地浸砂岩铀矿勘查技术和找矿勘探过程中地浸可行性评价技术，并论述了技术内容和技术开发目标。两项关键技术的开发研究和落实对扩大我国铀矿资源有现实意义。  相似文献   

城市地下管线综合探测   总被引：3，自引：0，他引：3  

桂向阳  应晓建 《地球科学》1993,18(3):362-367

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伸展地区铲式正断层作用及其大地测量观测   总被引：1，自引：1，他引：1  

桂Kun长 《地质论评》1993,39(3):196-204

铲式正断层作用是伸展构造区最主要的构造运动形式。本文根据铲式正断层作用的几何学、运动学特征,结合华北平原伸展区大地测量观测成果,探讨伸展区构造形变铲式正断层现今活动的地表形变效应及其动态特征。  相似文献   

从唐山地震看人民群众在抗震减灾中的作用     

李贵 《国际地震动态》1993,(6):20-24

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Preliminary study on assessment of nutrient transport in the Taihu Basin based on SWAT modeling     

Lai Geying  Yu Ge  Gui Feng 《中国科学D辑(英文版)》2006,49(1):135-145

With the Taihu Basin as a study area, using the spatially distributed and mechanism-based SWAT model, preliminary simulations of nutrient transport in the Taihu Basin during the period of 1995:_2002 has been carried out. The topography, soil, meteorology and land use with industrial point pollution discharge, the loss of agricultural fertilizers, urban sewerage, and livestock drainages were all considered in the boundary conditions of the simulations. The model was calibrated and validated against water quality monitoring data from 2001 to 2002. The results show that the annual total productions of nitrogen (TN) and phosphorus (TP) into Lake Taihu are 40000t and 2000t respectively. Nutrient from the Huxi Region is a major resource for Lake Taihu. The non-point source (surface source) pollution is the main form of catchment sources of nutrients into Lake Taihu, occupied TN 53% and TP 56% respectively. TN and TP nutrients from industrial point pollution discharge are 30% and 16%, and sewerage in both forms of point source and non-point source are TN 31% and TP 47%. Both the loss of agricultural fertilizers and livestock drainages from the catchment should be paid more attention as an important nutrient source. The results also show that SWAT is an effective model for the simulation of temporally and spatially nutrient changes and for the assessment of the trends in a catchment scale.  相似文献   

Erratum to: LICOM Model Datasets for the CMIP6 Ocean Model Intercomparison Project     

Pengfei LIN  Zhipeng YU  Hailong LIU  Yongqiang YU  Yiwen LI  Jirong JIANG  Wei XUE  Kangjun CHEN  Qian YANG  Bowen ZHAO  Jilin WEI  Mengrong DING  Zhikuo SUN  Yaqi WANG  Yao MENG  Weipeng ZHENG  Jinfeng MA 《大气科学进展》2020,37(6):662-662

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西天山卡拉达湾地区铀及多金属综合找矿方向研究          下载免费PDF全文

陈江源  段晨宇  牛家骥  陈志鹏  尚景武 《地质找矿论丛》2020,35(1):25-32

卡拉达湾地区位于新疆北天山西段,属于中亚造山区,是在前寒武纪基底陆壳裂解的基础上发展起来的陆间型造山带,是铀及多金属成矿的重要区域。本文在前人工作的基础上,依据地面磁测、地面伽玛总量测量结果,总结分析了卡拉达湾地区磁场、放射性场、构造、矿化蚀变特征与铀及多金属成矿的关系,并圈定了铀及多金属找矿有利地段各2处,为西天山卡拉达湾地区的铀及多金属矿找矿工作提供方向。  相似文献   

Robust biased estimation and its applications in geodetic adjustments   总被引：6，自引：0，他引：6  

Q. Gui  J. Zhang 《Journal of Geodesy》1998,72(7-8):430-435

In this paper, a number of robust biased estimators (e.g. ordinary robust ridge estimator, robust principal components estimator, robust combined principal components estimator, robust single-parametric principal components estimator, robust root-root estimator) are established by means of a unified expression of biased estimators and based on the principle of equivalent weight. The most attractive advantage of these new estimators is that they can not only overcome the ill-conditioning of the normal equation but also have the ability to resist outliers. A numerical example is used to illustrate that these new estimators are much better than the least-squares estimator and various biased estimators even when both ill-conditioning and outliers exist. Received: 14 November 1995/Accepted: 11 February 1998  相似文献