An assessment of variations in mercury deposition to Antarctica over the past 34,000 years     

尹雪斌  孙立广  谢周清 《极地研究(英文版)》2003,14(2)

We performed a comparison analysis of the variations .in Mercury ( Hg) concentrations and the precipitation proxies ( e. g. , 18 O values and 10 Be concentrations) in the Dome C ice core. The results showed that there were significant correlations between Hg and δ 10O values, 10Be concentrations, indicating that the accumulation rate in Dome C is one of the key factors controlling the variations of Hg concentrations in the past 34 ,000 years, and implying that Hg concentrations in ice core can be used as another reliable proxy of precipitation rate in Antarctica. Based upon the high-resolution δ 18O values, we estimated the variations in mercury deposition flux to Antarctica over the past 34,000 years. The highest mercury deposition flux is about 3. 80 pg cm-2 yr-1 during the Last Glacial Maxium (LGM) as high as 3. 5 times of the mercury deposition flux ( about 1. 08 pg cm -2 yr -1) in Holocene due to the fluctuations in natural mercury emissions such as the oceanic biological emissions.  相似文献   

Development and application of water environment management information system based on ARCGIS Engine     

Beijia HUANG  Shaoping WANG  Jun CAO College of Environment Science  Engineering  Key Laboratory of Yangtze River Water Environment  Ministry of Education  Tongji University  Shanghai  China 《东北亚地学研究》2008,11(3):174-176

Embedded ArcGIS Engine can improve development efficiency of environmental information system. The authors designed the structure, functions and database of the Yongjiang River Basin Water Environment Management Information System （YRBWEMIS） through the integration of ArcGIS Engine software with VC. The spatial data and attribute data in the YRBWEMIS are stored and managed separately. The system functions include display, query., statistics, spatial analysis and thematic mapping for water pollution sources, water quality, water function regionalization and catchments region.  相似文献   

反演奇异模型的参数估计的通用公式   总被引：1，自引：1，他引：0  

陶本藻  张朝玉 《大地测量与地球动力学》2004,24(3):7-10

将大地测量反演问题中的线性模型，综合为一般模型，称为反演奇异模型。运用最小二乘统一理论给出了反演奇异模型的参数和单位权方差通用估计公式，给出了这种模型的验前验后方差一致性检验方法。讨论了反演参数估计的有关问题。  相似文献   

Soluble species in aerosols collected on the route of the Second Chinese National Arctic Research Expedition     

徐建中  孙俊英  任贾文  秦大河 《极地研究(英文版)》2005,16(1):1-12

Aerosol samples are collected on the route of the Second Chinese NationalArctic Research Expedition from July 15 to September 28,2003.The concentration ofwater soluble ions(Na~+,NH_4~+,Ca~(2+),Cl~-,MSA,SO_4~(2-)and so on)are ana-lyzed.By correlation analysis,the ions can be divided into three groups:(1)Na~+,Mg~(2+),K~+,Ca~(2+),Cl~-,SO_4~(2-),mainly from sea salt;(2)NH_4~+,NO_3~-,markedlyfrom coastal regions of the continents;(3)Acetate,MSA,C_2O_4~(2-),from othersources.Marine aerosols are the dominant origin,Cl~- and Na~+ are the most domi-nant anion and cation,respectively and these two ions(Na~++Cl~-)account for 55.6% of the total aerosol loading.The mean equivalence ratio of NH_4~+/SO_4~(2-)is 0.45,we suggest that ammonium and sulfate exist mainly as NH_4HSO_4.The concentrationof NO_3~- shows three different patterns on the route of expedition:Japan Sea with me-dian value of 15.2 neq·m~(-3);Sea of Okhostk and Bering Sea of 1.8 neq·m~(-3)andArctic Ocean of 0.4 neq·m~(-3).Bering Sea is a high MSA area.Through the com-parison of the concentration of main water soluble ions between the First and SecondChinese National Arctic Research Expedition,the variation matches each other.  相似文献   

Characteristics of carbonaceous aerosol in a two-week campaign at Ny-lesund     

谢周清  王新明  孙立广  龙楠烨  程帮波 《极地研究(英文版)》2005,(2)

The concentrations of organic carbon(OC)and elemental carbon(EC)in total suspended particle(TSP)were investigated at Ny-Alesund,Svalbard in atwo-week campaign.The levels of OC and EC are 0.86±0.27μgm~(-3)(mean±standard deviation)and 0.19±0.10μgm~(-3),respectively.Back trajectory analy-sis of air masses arriving at Ny-lesund reveals that long-range transport of pol-luted air play insignificant role in OC and EC levels,to which the potential influ-ence of the local contamination were ascribed.The average OC/EC ratio is 5.41,suggesting the presence of the secondary organic aerosols.The estimated second-ary organic carbon(SOC)in TSP is 0.59μg/m~3,accounting for 64% of the totalorganic carbon.  相似文献   

地表垂直变形序列的多尺度特征分析     

王坚高井祥  赵东保蔡建新 《测绘学院学报》2005,22(3):169-171

基于Morlet小波变换的方法对地表沉降数据序列进行多尺度特征分析，主要是周期性信息的多尺度描述。展现了沉降序列的频率特征在时域上的表现。小波变换能够清晰的给出不同尺度的强弱和分布情况以及沉降变化的趋势和突变点，以某矿的工业广场10个月19期2周等时间间隔的沉降数据序列为俐。分析了沉降数据中显含2．1和4．1个月的主周期信息。说明小波变换在沉降数据序列的分析中具有优越的性质。  相似文献   

基于MO和ArcSDE的城镇地籍建库工具箱开发与应用     

黄华国  汤军  王蕾 《国土资源信息化》2005,(1):32-34,44

城镇地籍数据建库是一项系统性、工程性和技术性相结合的工作。为了高效地、高质 量地、高水平地完成测绘数据的交换处理、权属数据的录入和图属一致控制,开发并 应用一套城镇地籍建库工具集具有极其重要的意义。本文基于MO和ArcSDE设计并 开发了企业级的建库工具箱,集中了各个环节的工具,为北京市城镇地籍建库提供了 有力支持。  相似文献   

地质灾害远程会商及应急指挥系统建设初探   总被引：4，自引：0，他引：4  

陈辉  曾青石  张鸣之  薛群威  张斌 《国土资源信息化》2005,(4):21-23,31

本文提出了构建于卫星通讯网络的地质灾害远程会商及应急指挥系统建设的初步设想。初步构建由网络通讯平台、信息资源管理平台、信息分析及决策支持平台、信息发布及应急指挥平台组成的综合信息系统。  相似文献   

一种改善MT低频数据质量的方法及其应用   总被引：2，自引：3，他引：2  

胡玉平  鲍光淑等 《地质与勘探》2002,38(3):46-48

电磁干扰是影响大地电磁测深方法（MT）数据质量的主要因素。目前，除从仪器电路上考虑压制50Hz的工业干扰外，主要的压制干扰的方法为近，远参考的ROBUST技术，它对高频电磁干扰或随机干扰有明显的压制作用。但在强干扰地区（通常具有很强的低频电磁干扰，如长，短脉冲和方波等低频干扰），低频数据的质量仍然很差，这是因为在低频数据处理时，强的低频电磁干扰使得级联分样后的数据发生了强的崎变，与实际的有用信号相差甚远，从MT时序数据出发，提出了应用小波变换的方法，重组低频干扰并加以消除，达到提高信噪比的目的，经实际资料处理证明，此方法效果明显。  相似文献   

青海贵德盆地晚新生代沉积演化与青藏高原北部隆升   总被引：12，自引：0，他引：12  

宋春晖  方小敏  李吉均  高军平  孙东  聂军胜  颜茂都 《地质论评》2003,49(4):337-346

青海贵德盆地发育巨厚的新生代地层,并含较丰富的重要哺乳动物化石,对确定盆地及周边相似地层的年代和研究高原隆升过程具有重要的科学意义。本文结合哺乳动物采用典型剖面精确古地磁测年为基础的时间框架,对近11 Ma BP以来盆地沉积相进行了分析,划分出19个沉积岩相和湖泊、三角洲、辫状河流、水下扇三角洲和水上洪积扇5个沉积环境,以及8个沉积演化阶段。通过盆地沉积对构造隆升的响应探讨表明:>11～7.65Ma BP为高原构造稳定期,7.65～3.6Ma BP高原具阶段性逐步隆升构造特征,3.6～>2.6 Ma BP为高原整体快速隆升,2.6Ma BP左右高原大规模挤压断陷,1.8 Ma BP左右高原大规模整体快速隆升并使贵德盆地古湖被切穿排干,黄河在此诞生。  相似文献