Biomarkers in the Molar Tooth （MT）-Bearing Limestones in the Jilin-Liaoning Area of China   总被引：2，自引：1，他引：2  

旷红伟  李艳霞  曾艳涛  孟祥化  葛铭 《中国地球化学学报》2004,23(4):334-341

The origin of Molar Tooth (MT) carbonates has been argued for more than 100 years, which are a kind of Proterozoic carbonates especially composed of microsparite with ptygmatically folded and sheet-like structures. Biomarkers detected in the microcalcsparite from the Wanlong and Xingmincun formations in the Jilin-Liaoning area showed there are abundant normal alkanes, isoprenoids, hopanes, steranes, alkylmethylcyclohexanes, and alkyleyclohexanes, indicating a diversity of biological source: long-chain isoprenoids, the major components of chlorophyll, such as C19, C20, a kind of major biomarkers synthesized early by isoprenoid monomers; hopanes a type of characteristic biomarkers from prokaryote, such as archaebacteria and cyanobacteria; sterane a biomarker for eukaryote; and two kinds of alkanes with C17, C18 as the main peaks representing aquatic bacteria and with C23, C24 as the main peaks representing fungi, respectively. Biomarker analysis showed that MT is the result of bacterial and algal activities, which is a kind of organisms between aerobic and anaerobic bacteria, reproducing well in normal or slightly saline sea water under weak oxidation-reduction conditions, resulting in rapid deposition of calcite as microsparite clue to some mechanisms.  相似文献   

Geophysical exploration for interlayer slip breccia gold deposits: example from Pengjiakuang gold deposit, Shandong Province, China     

Z. Qingdong  S. Yuanchao  L. Tiebing  L. Guangming  Z. Qirui  S. Kunfa  L. Hongchen  S. Xiuying  Y. Jinzhong 《Geophysical Prospecting》2004,52(2):97-108

Interlayer slipping breccia‐type gold deposit – a new type of gold deposit, defined recently in the northern margin of the Jiaolai Basin, Shandong Province, China – occurs in interlayer slip faults distributed along the basin margin. It has the features of large orebody thickness (ranging from 14 m to 46 m, with an average thickness of 30 m), shallow embedding (0–50 m thickness of cover), low tenor of gold ore (ranging from 3 g/t to 5 g/t), easy mining and ore dressing. This type of gold deposit has promising metallogenic forecasting and potential for economic exploitation. A ground gamma‐ray survey in the Pengjiakuang gold‐ore district indicates that the potassium/thorium ratio is closely related to the mineralization intensity, i.e. the larger the potassium/thorium ratio, the higher the mineralization. The gold mineralized alteration zone was defined by a potassium/thorium ratio of 0.35. A seismic survey confirms the location of the top and bottom boundaries and images various features within the Pengjiakuang gold mineralization belt. The gold‐bearing shovel slipped belt dips to the south at an angle of 50–55° at the surface and 15–20° at depth. The seismic profile is interpreted in terms of a structural band on the seismic section characterized by a three‐layered model. The upper layer is represented by weakly discontinuous reflections that represent the overlying conglomerates. A zone of stronger reflections representing the interlayer slip fault (gold‐bearing mineralized zone) is imaged within the middle of the section, while the strongest reflections are in the lower part of the section and represent metamorphic rocks at depth. At the same time, the seismic reflection survey confirms the existence of a granite body at depth, indicating that ore‐forming fluids may be related to the granite. A CSAMT survey showed that the gold‐bearing mineralized zone is a conductive layer and contains a low‐resistivity anomaly ranging from 2 Ωm to 200 Ωm.  相似文献   

Seismic performance evaluation of steel arch bridges against major earthquakes. Part 1: dynamic analysis approach     

Tsutomu Usami  Zhihao Lu  Hanbin Ge  Takeshi Kono 《地震工程与结构动力学》2004,33(14):1337-1354

In this study the inelastic behavior of steel arch bridges subjected to strong ground motions from major earthquakes is investigated by dynamic analyses of a typical steel arch bridge using a three‐dimensional (3D) analytical model, since checking seismic performance against severe earthquakes is not usually performed when designing such kinds of bridge. The bridge considered is an upper‐deck steel arch bridge having a reinforced concrete (RC) deck, steel I‐section girders and steel arch ribs. The input ground motions are accelerograms which are modified ground motions based on the records from the 1995 Hyogoken‐Nanbu earthquake. Both the longitudinal and transverse dynamic characteristics of the bridge are studied by investigation of time‐history responses of the main parameters. It is found that seismic responses are small when subjected to the longitudinal excitation, but significantly large under the transverse ground motion due to plasticization formed in some segments such as arch rib ends and side pier bases where axial force levels are very high. Finally, a seismic performance evaluation method based on the response strain index is proposed for such steel bridge structures. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

西藏降水量、气温变化特征及相关关系   总被引：9，自引：2，他引：9       下载免费PDF全文

葛朝霞  王会容  曹丽青  王晓兰 《气象科学》2004,24(4):468-473

本文利用40a逐日降水与气温资料，分析了西藏地区降水量、气温的年变化和年代际变化特征，讨论了气温与降水量的相关关系。结果表明：近几十年来，西藏年平均气温、降水量有明显上升的趋势；气温是影响西藏地区降水量的重要因子之一。绝大多数月份的月平均降水量与前期气温有很好的相关关系，可作为月平均降水量预报的参考依据。  相似文献   

地质雷达快速检测运营公路隧道隐患   总被引：4，自引：0，他引：4  

赵天库  葛为中  张忠良 《上海国土资源》2004,18(3):62-66

为了评价运行多年隧道的衬砌质量，查找隐患，开展了拱顶的地质雷达无损快速检测。在雷达波形剖面图上分析空洞、不密实异常，推断出大量隐患。物探成果经过开凿验证，证明其隐患定位成功率在85％以上。地质雷达快速检测方法为隧道病害治理提供了可靠的基础资料。  相似文献   

基于DOM的宁波市城市用地调查     

葛纪坤 《现代测绘》2004,27(2):38-39

介绍以DOM，进行城市用地调查方式，极大的提高了调查的效率。  相似文献   

Geochemistry of ore-forming fluids and geological significance of the Kuoerzhenkuola gold field in Xinjiang, China     

SHEN Ping  SHEN Yuanchao  LIU Tiebing  LI Guangming & ZENG Qingdong Institute of Geology  Geophysics  Chinese Academy of Sciences  Beijing  China 《中国科学D辑(英文版)》2005,48(11)

The Kuoerzhenkuola gold field (including the Kuo- erzhenkuola and the Buerkesidai gold deposits), lo- cated 68 km east of Jimunai County in northern Xing- jiang, China, is an important component of the Sawuer gold belt which is the eastward extending part of the Zarma-Sawur gold-copper belt in Kazakhstan. Some studies are concerned with the geology of the gold ores[1―3], the associated volcanic rocks[4], radiogenic isotope[5―8], and the ore-forming environment[8]. Most researchers inferr…  相似文献   

Real-time retrieval of precipitable water vapor from GPS and BeiDou observations   总被引：3，自引：2，他引：1  

Cuixian Lu  Xingxing Li  Tobias Nilsson  Tong Ning  Robert Heinkelmann  Maorong Ge  Susanne Glaser  Harald Schuh 《Journal of Geodesy》2015,89(9):843-856

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Carbon isotopic (14C and 13C) characterization of fossil-fuel derived dissolved organic carbon in wet precipitation in Shandong Province,China     

Xuchen Wang  Tiantian Ge  Caili Xu  Yuejun Xue  Chunle Luo 《Journal of Atmospheric Chemistry》2016,73(2):207-221

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Classifying Human Activity Patterns from Smartphone Collected GPS data: A Fuzzy Classification and Aggregation Approach          下载免费PDF全文

Neng Wan  Ge Lin 《Transactions in GIS》2016,20(6):869-886

Smartphones have emerged as a promising type of equipment for monitoring human activities in environmental health studies. However, degraded location accuracy and inconsistency of smartphone‐measured GPS data have limited its effectiveness for classifying human activity patterns. This study proposes a fuzzy classification scheme for differentiating human activity patterns from smartphone‐collected GPS data. Specifically, a fuzzy logic reasoning was adopted to overcome the influence of location uncertainty by estimating the probability of different activity types for single GPS points. Based on that approach, a segment aggregation method was developed to infer activity patterns, while adjusting for uncertainties of point attributes. Validations of the proposed methods were carried out based on a convenient sample of three subjects with different types of smartphones. The results indicate desirable accuracy (e.g. up to 96% in activity identification) using of this method. Two examples are provided in the Appendix to illustrate how the proposed methods could be applied in environmental health studies. Researchers could tailor this scheme to fit a variety of research topics.  相似文献