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This study aims to develop a joint probability function of peak ground acceleration (PGA) and cumulative absolute velocity (CAV) for the strong ground motion data from Taiwan. First, a total of 40,385 earthquake time histories are collected from the Taiwan Strong Motion Instrumentation Program. Then, the copula approach is introduced and applied to model the joint probability distribution of PGA and CAV. Finally, the correlation results using the PGA‐CAV empirical data and the normalized residuals are compared. The results indicate that there exists a strong positive correlation between PGA and CAV. For both the PGA and CAV empirical data and the normalized residuals, the multivariate lognormal distribution composed of two lognormal marginal distributions and the Gaussian copula provides adequate characterization of the PGA‐CAV joint distribution observed in Taiwan. This finding demonstrates the validity of the conventional two‐step approach for developing empirical ground motion prediction equations (GMPEs) of multiple ground motion parameters from the copula viewpoint. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Rong Xiao Junhong Bai Qinggai Wang Haifeng Gao Laibin Huang Xinhui Liu 《洁净——土壤、空气、水》2011,39(7):612-618
Surface soils were collected in the aquatic–terrestrial ecotone (ATE) of Yongnianwa wetland, downstream of Haihe River basin of North China in June of 2007. Samples were subjected to a total digestion technique before they were analyzed for total concentrations of Cr, Cu, Ni, Pb, and Zn to investigate their pollution levels in the ATE. The contamination index, integrated contamination index, geoaccumulation index, toxic units, and sum of toxic units were adopted to assess the heavy metal contamination levels and ecotoxicity, respectively. The results showed all the selected element concentrations in upland soils of the ecotone were relatively higher than those in the lowland soils. No Cr pollution was observed in all soil samples, but almost all samples were slightly polluted by Cu, Ni, Pb, and Zn except for Site 1. The contamination indexes and geoaccumulation indexes consistently presented no contamination for Site 1 and slight contamination for other sites. The ΣTUs increased from lowland to upland, but the whole level of toxicity in this ecotone was relatively low. 相似文献
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从等值线图形获取DAT和GRD格式的数据文件 总被引:2,自引:0,他引:2
在盆地模拟研究工作中,需要处理大量的地质数据和地质图件,一方面,随时需要把各种数据变为可视的图形;另一方面,还时常需要从图形中得到研究中所必需的数据,例如,由构造图得到研究区域的深度数据文件。本文介绍一种从等值线图形获取DAT格式和网格化GRD格式的数据文件的方法。 相似文献
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苇湖梁煤矿已有50多年的开采历史, 长期的地下开采造成了严重的地面塌陷。本文将新疆苇湖梁煤矿塌陷区作为研究区, 以2013年的IKONOS高分遥感影像为主要数据源, 以ArcGIS为支撑平台, 采用人机交互的解译方法对塌陷区的相关信息进行提取, 结合实地调查验证的方法, 分析研究区内地质灾害的特征。通过遥感调查发现: 研究区内发育规模较大、位于塌陷区周围的拉伸区的地裂缝约有64条;塌陷坑(群)约有94个, 主要分布于南北塌陷槽及两侧;塌陷回填区总面积达0.92 km2, 并在回填区发现了3个新塌陷坑。本文充分发挥了遥感技术宏观性强、速度快的特点, 调查结果反映了塌陷区灾害的实际情况。 相似文献
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采用基础摩擦隔震房屋高宽比限值的研究 总被引:12,自引:3,他引:12
大量的试验结果和地震经验表明,采用基础隔震方法能有效地提高建筑物的抗震能力,但建筑物的高度在什么范围,即建筑物的高宽比在什么范围内才适合采用这种方法,仍然是一个有待解决的课题。本文对采用基础滑移隔震多层砌体房屋在实际地震作用下的抗倾覆高宽比限值进行了研究,利用Wilson-θ数值积分方法计算,得到了多层砌体房屋的高宽比限值的统计值。其数值结果可供编制建筑隔震设计规程参考。 相似文献
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Bing-Xiang Liu Yue Qi Wei Wang Wolfgang Siebel Xi-Yan Zhu Hu Nie Jian-Feng He Fukun Chen 《International Journal of Earth Sciences》2013,102(8):2153-2173
The Qinling Group was previously interpreted as the oldest Precambrian basement unit of the North Qinling Terrain, recording its formation and early crustal evolution. The Qinling Group consists predominantly of gneisses, amphibolites, and marbles, which underwent multi-phase deformation and metamorphism. In order to better constrain the provenance and tectonic setting of this group and the evolution of the North Qinling orogenic belt, in situ U–Pb dating and oxygen isotopic analysis of zircons in combination with whole-rock geochemistry and Sr–Nd isotope analysis was performed on the two dominant rock types, amphibolite and felsic gneiss. Felsic gneisses exhibit enrichment of LREEs and LILEs (Rb, Ba, Th, K, Pb), negative Eu anomalies and depletion of HFSEs (Nb, Ta, P, Ti). The rocks have slightly elevated δ18O values (6.5–9.3 ‰) and initial ε Nd values of ?4.6 corresponding to two-stage Nd model age of 1.99 Ga. Amphibolites are also enriched in LILEs and LREEs and depleted in Nb and Ta and have homogeneous δ18O values (5.0–6.0 ‰), but higher initial ε Nd values (2.8–3.3) and younger two-stage Nd model ages (1.29–1.24 Ga) compared to the gneisses. The zircon age record indicates that the gneisses and amphibolites were formed in a ~960 Ma volcanic arc environment rather than in a rift setting as previously suggested. A major metamorphic event took place during the Early Paleozoic. Based on the age spectrum of detrital zircons, the Qinling Group is interpreted as an autonomous geological unit, which was mainly derived mostly from 1,000 to 900 Ma old granitoid rocks. The North Qinling Terrain can be regarded as a remnant of the Grenville orogenic belt with an early Neoproterozoic evolution different from that of the North and South China blocks. 相似文献