GPS测站位移速率的解算方法   总被引：4，自引：1，他引：3  

孟国杰  顾国华  王武星 《大地测量与地球动力学》2003,23(3):21-25

对目前4种常用的利用GPS复测资料解算测站位移速率的方法进行了分析，通过实例对比了4种方法的结果。坐标法可以直接利用多期复测结果得到测站大地坐标，但要求坐标在同一参考框架内，并采用相同的参考椭球；基线方法可以消除或削弱观测系统的系统误差，与参考框架无直接关系，但在平差计算时至少要引入1个起算点，起算点高程方向的误差会削弱其他点平面坐标的精度，并进而影响位移速率的精度；在选定不同基准解算位移速率时相似变换方法是十分有效的，但如果复测结果不在同一参考框架中，其结果存在框架不一致所带来的误差；QOCA方法能够综合利用多种观测数据，可以把区域观测数据和全球观测数据稳健地结合起来，在削弱观测期间突变因素的影响方面比其他方法具有便利之处。  相似文献   

Development,territorial difference and spatial evolution of towns in China—A discussion on the views of anti-urbanism in China     

Chaolin Gu 《中国地理科学(英文版)》1996,6(3):201-211

Growth of Chinese small towns is a continuing process of urbanization. By analyzing regional disparity and comprehensive development level of Chinese small towns, it is considered that town development depends mainly on the regional agriculture and social development level. Their spatial distribution is restricted by population distribution and regional economic development level. Chinese urbanization, just the same as urbanization in developed countries, is a sign of socio-economic vigour and prosperity, and is not related to social and political systems. Thus, it is worth to discuss China’s anti-urbanism with abroad scholars.  相似文献   

Feeding habits and food composition of half-fin anchovy,Setipinna taty (C et V) in the Bohai Sea     

Gu Hong 《中国海洋湖沼学报》1990,8(3):280-288

Analysis of the contents of 3,479 stomachs of half-fin anchovy (taken monthly from April 1982 to May 1983 from the Bohai Sea) shows that half-fin anchovy is a zooplanktivorous fish; the young fish feeds mainly on Copepoda while the adult fish feeds mainly on Mysidacea andAcetes chinensis; the food composition has a seasonal change, the main food is Mysidacea in spring butAcetes chinensis in summer and fall; the feeding intensity is closely related to its spawning. Contribution No. 1781 from the Institute of Oceanology, Academia Sinica.  相似文献   

STUDY ON BUSINESS POLLUTION AND ITS COUNTERMEASURES IN SHANGHAI   总被引：1，自引：0，他引：1  

杨凯  王云  甘湘南  顾频 《中国地理科学(英文版)》1997,7(4):352-360

I.saclybaCKGROUNDThetermofbusinesspollutioninthispaperreferstothereverseeffectsontheenviro~entandhumanhealtharisingfromtheprocessesofprofitablecornnlercialactivities.Itmainlyincludesnoisepollution,oilsmokePOllution,heatPOllution,wastewaterpollutionfromrestaurantIplasticpackagepollutionandlightPOllution.Duringtheprocessofindustrialrestructuringandtheeconomicdevelopment,theproportionofthetertiaryindustryinShanghai'sgrossdomesticproduction(GDP)rosefrom30.8%in1990to40.1%in1995.Inthefollowi…  相似文献   

试论我省覆盖区区域地球化学调查     

顾金秋 《浙江国土资源》2001,17(2):12-16

本文主要论述了覆盖区进行125万多目标区域地球化学调查的特点及其基本工作方法技术,并从我省覆盖区区域地球化学调查工作的现状出发,提出下步工作的设想.  相似文献   

基于深度学习网络的地震地质灾害识别研究     

肖本夫  吴今生  毛利  顾铁  梁远玲  代友林 《震灾防御技术》2021,16(4):617-624

遥感影像识别方法是破坏性地震震后地质灾害快速、准确获取的重要方法之一,传统的遥感影像识别方法主要以人工目视识别方法和半自动识别方法为主,需投入大量的人力和时间。针对破坏性地震震后地质灾害解译时间长、投入人力多等问题,以2017年8月8日四川九寨沟7.0级地震震后高分辨率无人机遥感影像为研究样本,提出基于深度学习网络的地震地质灾害识别方法。首先结合震后遥感影像解译资料和现场调查资料,提取九寨沟地震地质灾害无人机遥感影像特征,并构建研究区地震地质灾害解译指标和分类数据集;然后采用DeepLabv3+网络结构及softmax损失函数,建立基于深度学习网络的地震地质灾害遥感影像图像语义分割模型方法;最后采用半监督学习方法进行结果验证。研究结果表明,基于深度学习网络的地震地质灾害识别方法可有效识别九寨沟地震地质灾害分布信息,整体分类识别准确率为94.22%,F₁分数值为0.77,结果具有较好的一致性和准确性,可提升地震现场灾情获取和重点地震隐患识别等工作效率及服务能力。  相似文献   

2021年6—9月全球火山活动简报     

顾国辉  康建红  贾若  关升 《中国地震》2021,37(4):924-928

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吉林省龙岗火山岩区早更新世粗面玄武岩地球化学特征及构造意义     

徐智涛  李萌萌  盘晓东  孙景贵  顾国辉  刘宏岩  马飞 《地震地磁观测与研究》2021,42(2):160-161

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反射地震在胶东西北部变质岩区深部构造探测中的应用     

王怀洪  朱裕振  孙超  王秀东  田思清  巩固 《地球物理学进展》2021,36(1):267-273

焦家、三山岛、招平作为胶东西北部三大主要控矿断裂带,控制了胶西北地区近80％以上的金矿储量.金矿主要沿断裂倾角变化的平缓部位和陡、缓转折部位富集,构成了"阶梯式"分布型式.在复杂的区域地质构造背景下,如何清晰准确地预测控矿构造陡缓相间的倾角变化规律,成为金矿深部勘查必须要解决的问题.为了查明胶西北深部构造变化特征,本文应用地震方法进行了探索尝试.结合研究区以往地质、物探资料,构建了本区薄层反射地质模型,通过正演模拟研究,分析了采集参数,指导采集并获得了较高质量数据;针对变质岩区地震资料信噪比低、构造倾角大等特点,通过组合去噪、时频反褶积等技术手段,提高了地震信噪比;分析了该区地震反射波特征,以断面或蚀变带反射波直接进行断裂构造解释.明确了主要控矿构造在纵向上整体具有上陡下缓的"铲式"的特点,构造倾角30°～50°,局部达70°以上,呈倾角陡、缓相间阶梯式展布形态,且南东倾向断裂规模较北西倾向大.根据解释结果,预测了断裂带深度,指导了钻孔布设并获得了验证.  相似文献   

Generation of realistic synthetic catchments to explore fine continental surface processes     

Raphaël Bunel  Nicolas Lecoq  Yoann Copard  Eric Guérin  Marco Van de Wiel  Nicolas Massei 《地球表面变化过程与地形》2021,46(3):593-610

Understanding, analysing, and predicting the erosion mechanisms and sedimentary flows produced by catchments plays a key role in environmental conservation and restoration management and policies. Numerical case-testing studies are generally undertaken to analyse the sensitivity of flood and soil erosion processes to the physical characteristics of catchments. Most analyses are conducted on simple virtual catchments with physical characteristics that, unlike real catchments, are perfectly controlled. Virtual catchments generally correspond to V-shaped valley catchments. However, although these catchments are suitable for methodical analysis of the results, they do not provide a realistic representation of the spatial structures of the landscape and field conditions. They can, therefore, lead to potential modelling errors and can make it difficult to extend or generalize their results. Our proposed method bridges the gap between real and traditional virtual catchments by creating realistic virtual catchments with perfectly controllable physical characteristics. Our approach represents a real alternative to traditional test case procedures and provides a new framework for geomorphological and hydrological communities. It combines a field procedural generation approach, geographic information system processing procedures, and the CAESAR-Lisflood landscape evolution model. We illustrate how each of these components acts in the process of generating virtual catchments. Five physical parameters were adjusted and tested for each virtual catchment: drainage density, hypsometric integral, mean slope of the main channel, granulometry, and land use. One of our virtual catchments is compared with a real catchment and a virtual catchment produced by a standard method. This comparison indicates that our approach can produce more realistic virtual catchments than those produced by more traditional methods, while a high degree of controllability is maintained. This new method of generating virtual catchments therefore offers significant research potential to identify the impacts of the physical characteristics of catchments on hydro-sedimentary dynamics and responses.  相似文献