用航摄像对制作全息地形立体图的新技术     

欧名付  马轩文  王荣  蒋继旺 《测绘学院学报》1996,(1)

全息地形立体图是将传统的光学机械立体投影术与全息术相结合，用航摄像对合成为一张具有一定焦深的近像面全息图。它既具有像面全息图衍射效率高，可以用扩展的白光光源再现的优点，也具有体全息图一定的波长和角度选择性。本文介绍了拍摄这种立体图的装置和方法，并从理论上对实验结果进行了一些分析，最后指出了它的应用前景。  相似文献   

龙门山断裂带测区古构造残余应力随深度分布及带中残余能量   总被引：1，自引：0，他引：1       下载免费PDF全文

安欧  高国宝 《地震地质》1996,18(1):25-29

以岩体正交异性弹性理论为基础，用Ｘ射线法，在龙门山断裂带测区，选取３个小区深钻孔系列的岩心，测量了岩体中宏观残余应力场的水平和铅直三维主分量、水平和铅直最大剪应力，及其应变能密度随深度的分布，分析了它们沿深度的分布规律，估算了该断裂带岩体中储存的宏观残余弹性应变能的量级  相似文献   

环境制图中数量特征的表示方法研究     

欧竹斌 《地理科学》1996,(1)

对环境制图中反映数量特征的定点符号法,包括几种连续和分级比率符号、非比率分级符号以及相关内容数量特征的表示进行了具体分析比较.对表示要素数量特征面状分布的网格法和等值线法,也结合实例进行了评述.  相似文献   

鲜水河断裂带古构造残余应力场对大地震的控制   总被引：1，自引：0，他引：1       下载免费PDF全文

安欧  高国宝 《地震地质》1993,15(2):139-147

以岩体正交异性弹性理论为基础,用X射线法,在鲜水河断裂带测区沿7条测线,测量了岩体三维残余应力,绘成区域残余应力等值线图、主应力线图及其应变能密度等值线图,探讨了其对带内大地震的控制作用  相似文献   

大地测量学家 周江文教授     

张赤军  欧吉坤 《测绘工程》1999,(2)

周江文教授是我国著名的大地测量学家和误差理论专家,八十有三的周老精神瞿铄,思维敏捷,充满着对我国大地测量事业和年轻同志成长的关心.他对我国大地测量的贡献更为学术界所赞赏.正如大地测量和固体地球物理学家许厚泽院士所评价:"周江文教授是我国大地测量和测量误差理论研究领域中最有造诣的一位优秀科学家.60多年来,他为大地测量学的发展作出了巨大贡献.他自1958年到中科院测地所工作,为我所科技事业发展和人才培养呕心沥血,作了很多贡献".他以严肃的态度治学育人,60年如一日,为我国大地测量学术界树立了一座丰碑.  相似文献   

Estimation of PM_(2.5) Mass Concentration from Visibility     

Denghui JI  Zhaoze DENG  Xiaoyu SUN  Liang RAN  Xiangao XIA  Disong FU  Zijue SONG  Pucai WANG  Yunfei WU  Ping TIAN  Mengyu HUANG 《大气科学进展》2020,37(7):671-678

Aerosols in the atmosphere not only degrade visibility, but are also detrimental to human health and transportation. In order to develop a method to estimate PM_(2.5) mass concentration from the widely measured visibility, a field campaign was conducted in Southwest China in January 2019. Visibility, ambient relative humidity(RH), PM_(2.5) mass concentrations and scattering coefficients of dry particles were measured. During the campaign, two pollution episodes, i.e., from 4-9 January and from 10-16 January, were encountered. Each of the two episodes could be divided into two periods. High aerosol hygroscopicity was found during the first period, when RH was higher than 80% at most of the time, and sometimes even approached 100%. The second period experienced a relatively dry but more polluted condition and aerosol hygroscopicity was lower than that during the first period. An empirical relationship between PM_(2.5) mass concentration and visibility(ambient aerosol extinction) under different RH conditions could thus be established. Based on the empirical relationship,PM_(2.5) mass concentration could be well estimated from visibility and RH. This method will be useful for remote sensing of PM_(2.5) mass concentration.  相似文献   

Cases-97: Late-Morning Warming And Moistening Of The Convective Boundary Layer Over The Walnut River Watershed     

Margaret A. LeMone  Robert L. Grossman  Robert T. Mcmillen  Kuo-Nan Liou  S.C. Ou  Stuart Mckeen  Wayne Angevine  Kyoko Ikeda  Fei Chen 《Boundary-Layer Meteorology》2002,104(1):1-52

Aircraft, radiosonde, surface-flux, and boundary-layer windprofiler data from the Cooperative Atmosphere Surface Exchange Study's 1997 field project, CASES-97, are combined with synoptic data to study the evolution of the vertically-averaged mixed-layerpotential temperature []and mixing-ratio [Q] onthree nearly-cloudless days from 1000 CST to 1200CST (local noon is approximately 1230 CST). This was achieved through examination of the terms in the time-tendency (`budget')equations for []and [Q]. We estimate three of the terms –local time rate of change, vertical flux divergence, andhorizontal advection. For the [Q]-budget, vertical flux divergence usually dominates, buthorizontal advection is significant on one of the three days. The [Q]-budget balances for two of the three days to within the large experimental error. For the -budget,vertical flux divergence accounts for most of the morningwarming, with horizontal advection of secondary importance.The residual in the -budget has the same sign for all three days, indicating that not all the heating is accounted for. We can balance the []-budgets to within experimental error on two of the three days by correcting the vertical-flux divergence for apparent low biases in the flux measurements of one of the aircraft and in the surface fluxes, and accounting for direct heating of the mixed layer by radiative flux divergence allowing for the effects of carbonaceous aerosols. The [];-budget with these corrections also balances on the third day if horizontal gradients from synoptic maps are used to estimate the horizontal advection. However, the corrected budget for this day does not balance if the horizontal gradient in the advection term is estimated using CASES-97aircraft and radiosondes; we suggest that persistent mesoscale circulations led to an overestimate of the horizontal gradient andhence horizontal advection.  相似文献   

软多边形地图要素弯曲识别模型及其应用研究   总被引：4，自引：0，他引：4  

罗广祥  陈晓羽  赵所毅 《武汉大学学报(信息科学版)》2006,31(2):160-163

以边界线构减点的坐标单调性变化分析为基础，提出了地图上软多边形要素弯曲识别模型，给定了弯曲的凸凹性定义，建立了弯曲的多种形态量化指标，规范了弯曲邻接关系的形式及确定方法。研究了模型在软多边形地图要素图形综合简化中的应用，形成了简化这类要素图形的三种基本手段。  相似文献   

副高边缘暴雨的多普勒雷达回波特征   总被引：7，自引：4，他引：7  

周雨华  黄小玉  黎祖贤  吴贤云  夏正龙 《气象》2006,32(1):12-17

利用常规观测资料和多普勒雷达探测资料，对2003-2004年湖南省4次副高边缘暴雨的天气形势和雷达回波特征进行了分析研究。结果表明：4次暴雨过程的副高位置适当，高空有低槽，中低层有低空急流和低涡切变线，地面上有冷锋。在基本反射率图上，低槽暴雨有S-N向的窄带回波特征、冷式切变线暴雨有准W—E向的积层回波特征、暖式切变线有NE—SW向的积层回波特征，但每一次暴雨过程不尽相同。在多普勒速度图上常出现低空急流、冷暖平流、冷锋、逆风区以及高层大风核等特征，并常是几种特征同时出现，有利于强降水产生。  相似文献   

基于能力谱法的SSI体系抗震pushover分析方法   总被引：1，自引：0，他引：1  

王凤霞  欧进萍 《地震工程与工程振动》2006,26(5):88-94

本文首先经过2次等效将土与结构相互作用的多自由度体系等效为单自由度体系,并给出了修正反应谱和等价能力谱的确定方法,进而提出了基于能力谱法考虑土与结构动力相互作用(SSI)效应的结构体系pushover分析方法(SSIPA);然后对3种不同高度考虑SSI效应的结构体系在5条地震动作用下采用本文提出的方法进行了算例分析,将结果与非线性时程分析的结果进行了比较,研究了本方法的适用性和准确性;最后,与建筑抗震设计规范的设计反应谱相结合,对9层考虑SSI效应的钢结构用本文提出的方法进行了弹塑性地震反应分析,根据我国抗震设计规范的规定进行抗震性能的评估验证了本方法的可行性。  相似文献