Dissolved constituents and Sr isotopes in river waters from a mountainous island – The Danshuei drainage system in northern Taiwan     

Hui-Yao Chu  Chen-Feng You 《Applied Geochemistry》2007

Taiwan is a typical active orogenic belt situated at the collision boundary between the Eurasian Continental Plate and the Philippine Sea Plate. Dissolved major and trace constituents, as well as Sr and Sr isotopes in river waters collected from the Danshuei River basin in northern Taiwan have been studied to evaluate chemical weathering processes. The results of principal component analysis show that the ion sources in these river waters can be categorized into 3 major components: chemical weathering, seasalt contribution and local anthropogenic input. The chemical weathering is the most dominant factor that contributes about 85% of total variances. Significantly increased Na/Cl and Ca/Cl, as well ⁸⁷Sr/⁸⁶Sr, were observed in most upper stream samples. The Na/Cl and Ca/Cl ratios in the Dahan Stream, however, are much higher than the Shindien Stream. Even though average rainfall is stronger in the Shindien drainage basin, chemical evidence from river waters supports less intense weathering in the region. Selective dissolution of secondary calcites explains the observed high Ca/Cl, Sr/Cl and Ca/Na in the Dahan Stream. These results highlight the potential importance of tectonic factors, such as uplift and physical erosion in studying chemical weathering in an active orogenic belt.  相似文献   

Damage of 1975 Haicheng Ms7.3 earthquake in the Korean Peninsula and its effect on Kyushu, Japan     

李裕澈秋教昇  石川有三 《地震学报(英文版)》2007,20(2):224-233

The 1975 Haicheng MS7.3 earthquake affected whole Korean Peninsula and even Kyushu,Japan.In this paperisoseismal map of this earthquake was drawn for these areas by sorting out and analyzing data systematically col-lected,furthermore,the characteristics of the earthquake damage were discussed.In the northern Korean Peninsula,the intensity is V in great majority of this area except local area with intensity VI,and the damage is basically inaccordance with typical characteristics of corresponding intensity grade.In the southern Korean Peninsula,theintensity is IV in large part of the area,however,in some big cities such as Seoul etc.,not only high buildingsshook strongly,but also some people appeared perceptions such as feeling dizzy and so on,and electrical servicewas interrupted on one or two districts because of transformer tripping.These phenomena could be caused by theeffect of long-period wave generated from a large earthquake on far-field.  相似文献   

Peak earthquake response of structures under multi-component excitations     

Zach Liang  George C. Lee 《地震工程与工程振动(英文版)》2007,6(4):357-370

Accurate estimation of the peak seismic responses of structures is important in earthquake resistant design. The internal force distributions and the seismic responses of structures are quite complex, since ground motions are multi- directional. One key issue is the uncertainty of the incident angle between the directions of ground motion and the reference axes of the structure. Different assumed seismic incidences can result in different peak values within the scope of design spectrum analysis for a given structure and earthquake ground motion record combination. Using time history analysis to determine the maximum structural responses excited by a given earthquake record requires repetitive calculations to determine the critical incident angle. This paper presents a transformation approach for relatively accurate and rapid determination of the maximum peak responses of a linear structure subjected to three-dimensional excitations within all possible seismic incident angles. The responses can be deformations, internal forces, strains and so on. An irregular building structure model is established using SAP2000 program. Several typical earthquake records and an artifi cial white noise are applied to the structure model to illustrate the variation of the maximum structural responses for different incident angles. Numerical results show that for many structural parameters, the variation can be greater than 100%. This method can be directly applied to time history analysis of structures using existing computer software to determine the peak responses without carrying out the analyses for all possible incident angles. It can also be used to verify and/or modify aseismic designs by using response spectrum analysis.  相似文献   

Estimation of peak relative velocity and peak absolute acceleration of linear SDOF systems     

by Jianwei Song  Yi-Lun Chu  Zach Liang  George C. Lee University at Buffalo  State University of New York  NY  USA Erratum to： Earthq Engrg ＆ Engrg Vib DOI： ./s---x 《地震工程与工程振动(英文版)》2007,6(2):213-213

We have found some mistakes in the article by Jianwei Song et al. (2007). The revisions arc given below: 1. "NEHRP 2003" in Figs.8 and 9 should be changed to "BSSC 2003". 2. "Tsopelas" or "Tsopelas method"  相似文献   

测井成果在准格尔煤田窑沟高岭岩普查找矿工作中的运用     

褚开智 《中国煤田地质》2007,19(5):65-67

简要介绍内蒙古自治区准格尔煤田高岭岩矿产资源的勘探方法,并通过高岭岩矿层在测井曲线上的反映,分析运用测井成果进行高岭岩普查找矿工作的可行性。根据工作区以往271个钻孔的测井资料及所施工8个钻孔的钻探成果,共解释高岭岩矿层361层,其中可靠达170层。通过测井成果与钻探成果、化验资料对比统计可知,其高岭岩层真厚度量测井解释厚度的80%。  相似文献   

全球气候变暖背景下登陆我国台风特征的分析   总被引：38，自引：4，他引：38  

曹楚  彭加毅  余锦华 《南京气象学院学报》2006,29(4):455-461

利用1949-2002年西北太平洋热带气旋、登陆我国台风和全球地面温度资料，对登陆我国台风的频数、强度以及登陆位置的年际变化，特别是趋势特征进行了分析，并与西北太平洋台风的变化特征作了对比。结果表明：在全球气候变暖背景下，我国登陆台风频数的减少趋势没有西北太平洋台风频数的减少趋势强；登陆台风的平均强度和极端强度均有减弱趋势，极端强度的减弱趋势尤为明显，但其强度弱于西北太平洋台风。在1968-2002年全球明显增暖时段，我国台风登陆位置偏向我国中部，西北太平洋台风在生命史中强度达最强时的位置有向北移动的趋势。  相似文献   

宁波市大榭岛地下储油罐区地表构造及其浅层地震探测研究     

张秋文  郝书俭  曲国胜  于之水  褚宝贵 《大地测量与地球动力学》1998,(4)

通过野外地表地质调查,建立了浙江省宁波市大榭岛地下储油罐区地表构造模型;结合浅层地震探测结果,研究了工程场区覆盖层厚度和基岩顶面埋深及深部构造特征。在此基础上,对场区的深、浅构造关系及地表和深部构造条件进行了综合分析和评价,认为：Ｆ１断裂可能从关外隧道西口北延到场区,并在近石弄堂一侧的海湾中入海;总的来说,除Ｆ１断裂带可能通过关外至石弄堂沿线附近,造成岩石连续性和完整性较差以外,场区其他大部分地区基岩的连续性和完整性较好;储油罐场区（应适当远离Ｆ１断裂）的透水性较差,是一良好的场址。  相似文献   

大天巨星系红移巡天     

褚耀泉  朱杏芬 《天文学进展》1998,(2)

星系的红移巡天是观测宇宙学中最基本的工作,有关宇宙大尺度结构研究中的许多关键问题,例如宇宙中最大结构的尺度,宇宙中大尺度结构的拓扑特征,以及有关宇宙物质分布的密度场和速度场的许多基本性质的研究,都依赖于覆盖面积足够大、极限星等足够暗的完备的星系红移大样本．通过对巡天的覆盖天区、巡天深度、选样方法、巡样率等方面的分析,比较了最近已完成的一些红移巡天（IRAS、CfA、SSRS、ORS和LCRS等）并对计划中的2dF和SDSS巡天计划作了简要介绍．  相似文献   

低温敏不育系水稻“冷灌繁种”技术微气象效应的数值试验   总被引：2，自引：0，他引：2  

储长树  罗孝和 《南京气象学院学报》1998,21(1):95-103

在田间试验基础上,从系统生态学的观点出发,构建了水稻田冠层－水层温度场耦合模型。通过对模型的不同输入,模拟了不同天气条件,不同水稻群体结构以及不同灌溉方案下的冷灌效应,对低温敏水稻冷繁技术的生产实施具有指导意义。  相似文献   

汛期相当暴雨日数与总降水量的定量关系   总被引：8，自引：1，他引：7  

吴正华  李海盛  储锁龙 《气象》1998,24(12):13-17

北京近百年汛期相当暴雨日数与汛期总降水量相关系数高达０．９７,京津冀地区３０年汛期区域平均相当暴雨日数与区域平均降水量相关系数亦达０．９４。通过点聚图和回归方程来表征两者的线性关系。汛期相当暴雨日数估算汛期总降水量的误差约１０％,即估算精度达９０％。这种估算方法可供业务使用。  相似文献