一次龙卷过程的多普勒天气雷达和闪电定位资料分析   总被引：6，自引：4，他引：6  

姚叶青  魏鸣  王成刚  李劲 《南京气象学院学报》2004,27(5):587-594

利用WSR-98D多普勒天气雷达和闪电定位资料分析了2003年7月8日发生在安徽省无为县境内的一次龙卷过程。此次龙卷产生于低空急流左侧，动力、热力条件均为较有利的大尺度环境，多普勒雷达回波分析发现，龙卷起源于中高层向低层发展的中-γ尺度气旋中。闪电定位资料分析表明，龙卷发生前10min闪电活动开始频繁。龙卷出现后负地闪明显加大，且龙卷闪电存在于雷暴的发展后期、成熟和消亡阶段。此次龙卷的一些基本特征与通常结论有所不同，(1)雷达反射率因子小于通常结论；(2)龙卷风暴发展高度不是很高，回波顶高仅6～9km，类似于普通雷暴；(3)闪电活动中以负地闪为主，正地闪较少，并未出现正地闪一度占主导地位的现象。  相似文献   

Revolution or evolution? New Zealand agriculture since 1984     

Willie Smith  Hayden Montgomery 《GeoJournal》2004,59(2):107-118

Agriculture was the primary target of moves to deregulate the New Zealand economy in 1984. Within twelve-months all production subsidies had been removed, including those for fertiliser and other inputs, as well as funding for drought relief, floods and other natural weather disasters. Whereas at the start of 1984, subsidies were estimated to represent as much as 33% of farm income, by 2003 this had fallen to less than 2% with most of this spent on agricultural research. The anticipated shift of thousands of people off the land did not appear to occur, and by conventional measures at least New Zealand agriculture in 2003 is a major success story. At the core of the changes imposed on agriculture was a commitment to remove all state or government distortions from the system and to fully expose the agricultural sector to market forces. This included wide-ranging and fundamental changes in the broad institutional context within which agriculture must operate. All this was achieved at great social cost and with a significant impact on the environment. In many respects New Zealand agriculture is now very different from that in 1984. Some sectors, such as dairying, have grown and become increasingly industrialised. On the other hand, sheep farming, particularly for wool has struggled to maintain its market share, while other enterprises have emerged as significant sources of income, including horticulture, viticulture and fruit. It is argued here that the trends evident in New Zealand agriculture since 1984 pre-existed the reform period and that the apparent success of the reforms evident at a national scale have not addressed or removed the fundamental problems which face New Zealand agriculture, just as they do modern agricultural systems elsewhere. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Integrating Environmental Education Into Business Schools' Educational Plans in Finland     

Liisa Rohweder 《GeoJournal》2004,60(2):175-181

Environmental education in business school context has a significant effect on the way companies view environmental problems. Business schools train the future decision makers who can, with their own attitudes and practical actions, influence the contribution of business to the process of ecologically sustainable development. However, several studies show that no systematic thinking has been undertaken within business education as to what the educational prerequisites of the process of ecologically sustainable development are. In this article, I will firstly analyze by means of environmental education how business polytechnics in Finland have taken into consideration ecologically sustainable development. Secondly, I will raise the starting points for the development of the implementation of environmental education as part of the business schools▪ educational plans. Integrating environmental education into the vocational courses is identified as being one of the most effective ways of increasing the effectiveness of environmental education. Thirdly, the emphasis is on identification of barriers of integrating environmental education into the educational plans of business polytechnics. Theoretically, the article is attached to the objectives and learning concepts of environmental education and to educational planning theory in general. The empirical data are based on interviews I conducted 1999–2000 in all Finnish polytechnics offering business education. My article increases theoretical and practical understanding of how environmental education should be implemented in business education and how the current situation could be developed. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

基于代理的移动定位服务AMLS     

刘小春何鸿君  敬必刚 《测绘学院学报》2004,21(4):292-294

介绍了基于代理Servlet的移动定位服务系统AMLS的系统架构，重点讨论了空间对象的高效查询和解析、移动用户GPS位置的获取和代理Servlet等关键技术的实现方法，并对AMLS进行了具体的实践。  相似文献   

电子地图商务网站应用探析     

杨晓超 《测绘信息与工程》2004,29(2):5-7

从WebGIS的产生背景和特点入手,阐述了WebGIS的应用现状,分析了WebGIS的重要应用之一--电子地图商务网站,剖析了其服务对象、系统需求、市场预测及策略等.  相似文献   

基于J2EE的移动定位服务研究   总被引：6，自引：0，他引：6  

陈能成  龚健雅  朱欣焰  刘琳 《武汉大学学报(信息科学版)》2004,29(1):48-51

阐述了基于J2EE的移动定位服务 (MLS)的体系结构 ,介绍了适于MLS的GIS应用服务器和信息设备地图可视化表达的关键技术 ,给出了GeoSurf的WAP和J2ME的两种解决方案 ,并阐述了其应用前景  相似文献   

The Globalization of a Panethnopolis: Richmond District as the New Chinatown in San Francisco     

Laguerre  Michel S. 《GeoJournal》2005,64(1):41-49

This paper briefly reviews the sociological literature on the “New” Chinatown phenomenon stressing its structural location vis-à-vis the “Old” Chinatown and the homeland. It defines the New Chinatown as a panethnopolis, that is a global neighborhood with a majority population of Chinese immigrants and of other ethnic groups of mostly Asian descent. It analyzes more particularly the formation, development, and integration of San Francisco’s Richmond District’s New Chinatown into both the city where it is located and the network of transglobal sites to which it belongs. It provides an interpretation of the New Chinatown as a cultural enclave within the context of globalization theory.  相似文献   

基于ArcGIS Add-in的交互式DLG质量检查平台搭建研究     

金丽华  钱枫  王晓波  朱李忠 《测绘与空间地理信息》2016,(3):152-154

DLG作为基础地理信息的核心数据,质量直接影响其在各个领域内的应用,为此,DLG质量检查尤为重要。基于现有检查软件的质检工作大多将检查和编辑分离成两个独立部分,使得错误信息的查看和修改不便。因此,基于ArcGIS Add-in研发了交互式DLG质量检查平台,将质检和编辑无缝衔接,实现随查随改的高效质量过程控制。  相似文献   

齐齐哈尔市地理国情分析与表达     

刘艳芳  方佳琳  焦利民  彭金金 《测绘与空间地理信息》2016,(3):5-8

以齐齐哈尔市为例,利用地理国情普查数据与统计年鉴数据,构建自然地表指数、地理区位指数、生态覆被指数,对齐齐哈尔市各县、区的地理国情进行综合分析和地图表达。结果表明,齐齐哈尔市的总体条件较好,但区域差异较大,自然地表条件与地理区位条件均以中部的齐齐哈尔市辖区为优,而生态覆被条件则以北部和西部地区为优。  相似文献   

“全息”地图研究初探     

张兰  郭佳  付飞  安利 《测绘与空间地理信息》2016,(6):96-98

地图产品种类层出不穷,全息地图近年来成为焦点走进人们的视野。本文首先明确了与全息地图相近的三维地图和全景地图的概念;然后,简要阐述了传统的光学全息地图与新兴的全息位置地图的概念、原理以及几种地图产品的差别。在此基础上,分析了两种冠以"全息"二字地图的发展现状,并探讨了它们未来发展的主要方向。  相似文献