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41.
Ying Li Jianguo Du Fukuan Wang Xiaocheng Zhou Xiaodong Pan Ruqing Wei Institute of Earthquake Science China Earthquake Administration Beijing China Inner Mongolia Corporation Ltd.of Geologic Engineering Hohhot China Earthquake Administration of Jilin Province Changchun China Liaocheng Seismology Hydro-chemistry Test Station Liaocheng China 《地震学报(英文版)》2009,(1):93-100
The geochemical backgrounds and origins of soil gases in the Yanhuai basin are discussed based on the regional seismogeological data and concentrations of Rn,Hg,CO2,H2,He and CH4 in soil gas measured at 422 investigating sites in field during September to October 2007.The geochemical background values of Rn,Hg,CO2,H2,He and CH4 are(8105.8±5937.4) Bq/m3,(9.7±5.8) ng/m3,(395.9±35.3)×10-6,(4.0±2.3)×10-6,(15.9±10.4)×10-6 and(12.7±8.1)×10-6,respectively.The geochemical backgrounds of the soil gases are higher in... 相似文献
42.
Xiaoqing Wang Xiang Ding Long Wang Yan Wang Institute of Earthquake Science China Earthquake Administration Beijing China 《地震学报(英文版)》2009,(2):129-133
The paper introduces firstly the seismic loss assessment method based on macro-economic indicators and new vulnerability models determined by the data from the on-site damage and loss survey to earthquakes occurred in China during the last two decades.The fast assessment for the 2008 Wenchuan earthquake with MS8.0 is given based on an empirical intensity attenuation relationship.Compared with the assessment based on the practical seismic intensity map of the event according to the on-site investigation, the... 相似文献
43.
Peijian Shi Jie Liu Zhen Yang Agricultural College Jiangxi Agricultural University Nanchang China China Earthquake Networks Center Beijing China 《地震学报(英文版)》2009,(3):231-237
For exploring the aftershock occurrence process of the 2008 Wenchuan strong earthquake, the spatio-temporal point pattern analysis method is employed to study the sequences of aftershocks with magnitude M≥4.0, M≥4.5, and M≥5.0. It is found that these data exhibit the spatio-temporal clustering on a certain distance scale and on a certain time scale. In particular, the space-time interaction obviously strengthens when the distance is less than 60 km and the time is less than 260 h for the first two aftershoc... 相似文献
44.
Guoze Zhao Yan Zhan Lifeng Wang Jijun Wang Ji Tang Qibin Xiao Xiaobin Chen Institute of Geology China Earthquake Administration Beijing China 《地震学报(英文版)》2009,(4):395-402
Three experiments are carried out for earthquake monitoring using electromagnetic (EM) methods in recent years. Some earthquakes occurred in chance of the measurement time period for each experiment and the anomalies were recorded before the shocks. The observation at a site 20 km away from the epicenter of Zhangbei MS6.2 earthquake in 1998 shows that the apparent resistivity decreases in the strike direction before and/or during the earthquake and the resistivity increases in the de-cline direction. This a... 相似文献
45.
Jianping Wu Yuehong Ming Lihua Fang Weilai Wang Institute of Geophysics China Earthquake Administration Beijing China 《地震学报(英文版)》2009,(4):409-416
The S wave velocity structure in Changbaishan volcanic region was obtained from teleseismic receiver func-tion modeling. The results show that there exist distinct low velocity layers in crust in volcano area. Beneath WQD station near to the Tianchi caldera the low velocity layer at 8 km depth is 20 km thick with the lowest S-wave velocity about 2.2 km/s. At EDO station located 50 km north of Tianchi caldera,no obvious crustal low velocity layer is detected. In the volcanic re-gion,the thickness of crustal ... 相似文献
46.
Honglin Jin Hui Wang Institute of Earthquake Science China Earthquake Administration Beijing China 《地震学报(英文版)》2009,(6)
The Hori’s inverse method based on spectral decomposition was applied to estimate coseismic slip distribution on the rupture plane of the 14 November 2001 MS8.1 Kunlun earthquake based on GPS survey results.The inversion result shows that the six sliding models can be constrained by the coseismic GPS data.The established slips mainly concentrated along the eastern segment of the fault rupture,and the maximum magnitude is about 7 m.Slip on the eastern segment of the fault rupture represents as purely left-la... 相似文献
47.
Effects of precipitation and landuse on runoff during the past 50 years in a typical watershed in the Loess Plateau, China 总被引:2,自引:0,他引:2
Huaxing BI Bin LIU Jie WU Lei YUN Zhihan CHEN Zhewei CUI Prof. in hydrology College of soil water conservation Box Beijing Forestry University Qinghua East Road Haidian District Beijing China Researcher in hydrology Xifeng station of soil water conservation Xifeng Gansu Province China Graduate Assis. 《国际泥沙研究》2009,24(3):352-364
In the past century, great progress has been made worldwide in our understanding of forest-water relationship. The successful forestation programs implemented in China-which have improved the ecological environmental conditions-have gained the attention of many researchers and highlighted the relationship between forestation and water yields. The arid and semi-arid Loess Plateau has received attention from water engineers and eco-hydrological researchers in China because of a shortage in water resources. We selected one of the oldest stations conducting soil and water conservation experiments, the Xifeng soil and water conservation station, and chose the Nanxiaohe catchment and its paired catchments (Yangjiagou catchment and Dongzhuanggou catchment) as our research areas. Trends in precipitation, air temperature, streamflow over the past 50 years, and the effect of changing land use on streamflow were analyzed. The Mann-Kendall test showed that precipitation had a negative trend (downward trend), whereas air temperature showed a positive trend (upward trend) from the past to present in the Nanxiaohe catchment. However, the trends seen in precipitation, air temperature did not contain any "jumping points." The paired catchment approach is used to detect the effects of land cover change on hydrology in the Yangjiagou and the contrast catchment, i.e., Dongzhuanggou catchment in our study. The results showed a large change in land use in the Yangjiagou catchment from 1954 to 2008. An increase in forested land (from 0% to 40.08% from 1954 to 2008) and a reduction of bare land (from 51.26% to 5.50% from 1954 to 2008) accounted for a large part of the change in land use. However, the land use changed little in the contrast catchment. The comparison of streamfiow in the paired catchments showed that forestation reduced streamflow by 49.63% (or 6.5 mm) each year. 相似文献
48.
将锥束CT应用于口腔部位的三维成像,是近年来CT研究人员和口腔医生共同关注的一个热点.特别是随着牙齿种植技术的兴起,利用CBCT进行牙齿种植计划和手术导板的设计已成为一项新的研究方向.本文综述了口腔CBCT的成像原理和临床应用,比较了CBCT与传统CT在口腔成像中的特点,并总结了当前的关键技术和研究热点,供相关的技术及医学研究人员参考. 相似文献
49.
LIU Min HE HongLin YU GuiRui LUO YiQi SUN XiaoMin & WANG HuiMin Institute of Geographic Sciences Natural Resources Research Chinese Academy of Sciences Beijing China Gradute School of the Chinese Academy of Sciences Beijing School of Geography Science Nanjing Normal University Nanjing 《中国科学D辑(英文版)》2009,(2)
We present an uncertainty analysis of ecological process parameters and CO2 flux components (Reco, NEE and gross ecosystem exchange (GEE)) derived from 3 years’ continuous eddy covariance meas-urements of CO2 fluxes at subtropical evergreen coniferous plantation, Qianyanzhou of ChinaFlux. Daily-differencing approach was used to analyze the random error of CO2 fluxes measurements and bootstrapping method was used to quantify the uncertainties of three CO2 flux components. In addition, we evaluated different ... 相似文献
50.
ZHANG HuaQiao & DONG XiPing School of Earth Space Sciences Peking University Beijing China State Key Laboratory of Palaeobiology Stratigraphy Nanjing Institute of Geology Palaeontology Chinese Academy of Sciences Nanjing 《中国科学D辑(英文版)》2009,(6)
Although fossils of Orsten-type preservation represented by Skaracarida and Phosphatocopina were first reported from the Middle and Upper Cambrian in western Hunan, South China in 2005, diversified phosphatocopine species have never been appropriately described and elucidated in terms of their evolutionary relationships. Here, we described two new species of Phosphatocopina, Vestrogothia anterispinata sp. nov. and V. bispinata sp. nov. The evolutionary relationship among all the valid species of Phosphatoco... 相似文献