COMGIS的研究与实践     

杜娟  张正兰  刘耀东 《测绘信息与工程》2004,29(4):18-20

结合当前GIS技术的发展 ,讨论了COMGIS的定义、特性及原理 ,并结合实际应用 ,探讨了COMGIS的各种实现方式  相似文献   

降水对热带西南太平洋海温异常响应的数值试验   总被引：1，自引：3，他引：1       下载免费PDF全文

李娟  张铭 《气象科学》2004,24(2):154-160

本文应用IAP9-AGCMⅡ九层大气环流数值模式，通过数值试验，研究了降水对热带西南太平洋SSTA(海温异常)的响应。结果表明：海温正异常下，夏季北半球热带中太平洋降水明显偏多；我国东部地区降水正常或偏多。海温负异常下，夏季赤道中太平洋降水偏少，我国大部地区降水正常或略偏少。当该区域SST异常时，从总体看降水对该异常响应最敏感的地区为北半球热带中太平洋、我国华中和西南、孟加拉湾和中南半岛。  相似文献   

冰核浓度变化对云辐射的模拟试验   总被引：7，自引：0，他引：7  

李娟  毛节泰  胡志晋  游来光  张蔷 《气象学报》2004,62(1):77-86

文中利用中国气象科学研究院 2 0 0 0年版三维对流云模式 ,假设冰核浓度比现在模式中通常用来计算实际降水量的Fletcher给出的冰核浓度增大了 5倍 ,对北京地区 1996年 6～ 9月 18次降水过程作了模拟的对比分析。结果发现 ,80 %的模拟云在冰核浓度增大后都出现降水减小 ,云顶卷云毡面积扩大 ,云顶升高 ;95%的模拟云出现冰晶尺度变小 ,数量增多的现象。说明冰核浓度增大后 ,云的物理特性会有一些改变 ,并可能通过直接和间接作用改变辐射过程从而产生一定的气候效应  相似文献   

Loss on ignition: a qualitative or quantitative method for organic matter and carbonate mineral content in sediments?   总被引：5，自引：7，他引：5  

Juan I. Santisteban  Rosa Mediavilla  Enrique López-Pamo  Cristino J. Dabrio  M. Blanca Ruiz Zapata  M. José Gil García  Silvino Castaño  Pedro E. Martínez-Alfaro 《Journal of Paleolimnology》2004,32(3):287-299

Since the publication of the paper of , loss on ignition (LOI) has been widely used as a method to estimate the amount of organic matter and carbonate mineral content (and indirectly of organic and inorganic carbon) in sediments. The relationships between LOI at 550 °C (LOI₅₅₀) and organic carbon (OC) content and between LOI at 950 °C (LOI₉₅₀) and inorganic carbon (IC) content are currently accepted as a standard. However, the comparison of 150 analyses of samples of diverse lithologies, collected from a single core, reveals that these relationships are affected by sediment composition (presence of clays, salts, and the variable content of organic carbon). This results in an incremental error on the estimation of carbon content from LOI values that invalidates the use of LOI values as a quantitative method for estimating carbon content. Conversely, the general trends of LOI₅₅₀ and LOI₉₅₀ show a good correlation with carbon content (both organic and inorganic) allowing use of LOI as a qualitative test for carbon content. Similarly, in our case, LOI at 105 °C (LOI₁₀₅) is a good qualitative proxy for the trends in gypsum content.  相似文献   

Earthquake behavior of structures with copper energy dissipators     

Juan C. De la Llera  Carlos Esguerra  Jos L. Almazn 《地震工程与结构动力学》2004,33(3):329-358

The earthquake behavior of structures with supplemental copper dampers is evaluated in this study. The investigation is divided into two parts: (i) an experimental work with seven pairs of hourglass copper dampers of different aspect ratios and side profiles; and (ii) a parametric study of 6‐, 12‐, and 25‐story planar structures with elastic as well as inelastic behavior in the primary structure and copper dampers. The copper used in this study is electrolytic tough pitch (ETP) copper C11000; probably the most commonly used of all coppers; ductile, with a low‐yield, and highly resistant to corrosion. Experimental results demonstrate that all copper plates reached stable angular distortions of the order of γ=25%, which implies transverse distortions in the devices larger than 40mm. The behavior of the devices is highly dependent on the aspect ratio of the plate, h/t, and a recommendation is made to use plates in the range 11 h/t≤18. Plates beyond this range exhibit either large stress and strain concentrations in the neck of the device or a strong influence of axial deformations in their cyclic behavior. The inelastic earthquake response of structures with such devices shows that drift reduction factors of the order of 30 to 40% can be achieved with reasonably economic designs. It is also shown that the efficiency of these devices depends on the soil conditions and flexibility of the primary structure. Finally, it is concluded that supplemental copper dampers are a good alternative for drift reduction in a wide range of structural layouts, ranging from coupled shear‐wall systems to moment‐resisting frames, and for impulsive as well as non‐impulsive ground motions. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Analysis,testing, and implementation of seismic isolation of buildings in Chile     

Juan C. De la Llera  Carl Lüders  Patricio Leigh  Henry Sady 《地震工程与结构动力学》2004,33(5):543-574

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甘肃红石山地区蛇绿混杂岩地质特征   总被引：13，自引：6，他引：13  

魏志军  黄增保  金霞  孙永君  火军昌 《西北地质》2004,37(2):13-18

红石山蛇绿混杂岩产出于塔里木板块北缘红石山深大断裂带中。其物质组成反映出该杂岩形成于小洋盆环境。时代为早石炭世晚期，后经历了至少3期构造变形变质作用的叠加与改造。于二叠纪晚期运移至地表。作者进一步论述了红石山蛇绿岩的组成及变形变质特征，为研究北山北带提供了最新资料。  相似文献   

利用变形花岗岩体中的长石矿物进行有限应变测量初探   总被引：5，自引：2，他引：5  

王云斌  梁明宏  霍勤知  魏振伟 《西北地质》2004,37(2):19-24

岩石有限应变测量的方法较多，相比之下，“长短轴法”最简单、快捷，野外易于操作，但是对所选的对象变形前要求近圆形，或者椭圆形，且随机分布。花岗岩区很难找到满足此条件的颗粒。在《1：25万玉门镇幅》调研的过程中，试以长石颗粒为研究对象，进行长短轴法变形测量，将其结果与相邻变形砾石、杏仁体和包体测量结果进行对比，发现它们具有相似的应变椭圆轴率，证实在变形花岗岩区可以用变形长石颗粒研究区域变形的特点。  相似文献   

西藏普兰县马攸木金矿床石英的40Ar/39Ar年龄及其地质意义   总被引：5，自引：2，他引：5  

温春齐　多吉孙燕  范小平徐凌霍艳  格桑多庆　罗小军 《地质通报》2004,23(7):686-688

对西藏阿里地区马攸木金矿床含金石英脉样品进行40Ar/39Ar快中子活化法测年,其坪年龄为44.08Ma±0.39Ma,等时年龄为44.10Ma±0.20Ma,坪年龄代表石英的形成年龄。测试结果表明,西藏阿里地区可能存在喜马拉雅期金的成矿作用,且喜马拉雅期可能是西藏冈底斯-雅鲁藏布江成矿带形成金矿的主要时期。  相似文献   

某双曲线冷却塔施工放线测量   总被引：1，自引：0，他引：1  

肖娟  高俊强 《现代测绘》2005,28(2):31-32

结合某双曲线冷却塔施工测量工作，介绍了在测量新技术条件下复杂建筑的施工测量方法和技术。  相似文献