首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   648篇
  免费   25篇
  国内免费   15篇
测绘学   27篇
大气科学   25篇
地球物理   18篇
地质学   79篇
海洋学   8篇
综合类   33篇
自然地理   498篇
  2024年   1篇
  2023年   7篇
  2022年   30篇
  2021年   32篇
  2020年   32篇
  2019年   33篇
  2018年   30篇
  2017年   28篇
  2016年   37篇
  2015年   26篇
  2014年   21篇
  2013年   82篇
  2012年   33篇
  2011年   17篇
  2010年   25篇
  2009年   18篇
  2008年   24篇
  2007年   29篇
  2006年   19篇
  2005年   22篇
  2004年   17篇
  2003年   15篇
  2002年   12篇
  2001年   13篇
  2000年   20篇
  1999年   13篇
  1998年   9篇
  1997年   5篇
  1996年   2篇
  1995年   4篇
  1994年   4篇
  1993年   5篇
  1991年   2篇
  1990年   1篇
  1988年   5篇
  1987年   4篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
排序方式: 共有688条查询结果,搜索用时 31 毫秒
31.
Many tens of severe earthquake damage patterns were revealed at the ancient city of Ayla. The seismic deformation patterns are of various types, including systematic tilting of walls, systematic shifting and rotation of wall fragments and individual stones, arch deformations and joints crossing two or more stones. Features of later repair, supporting walls and secondary use of building stones suggest that the damage patterns can be explained by two historical devastating earthquakes: (I) revealed in the constructions built during the late Rashidun period (644–656 A.D.); (II) revealed in the structures restored and/or built during the Fatimid period (1050–1116 A.D.). The maximum observed intensity of both earthquakes at the studied site was not less than IX (EMS98 scale). The sources of the seismic events were probably the Dead Sea Transform and Wadi Araba Faults that cross the site obliquely. The last 1995 Nuweiba earthquake with maximum observed intensity VIII has also left its clear traces in the excavated ancient Ayla buildings. The severity of the destruction was significantly increased because of site effects.  相似文献   
32.
The subject of the security fence between Israel and the Palestinians in the West Bank has become a major issue in Israel and in the world in the last several years. The main aim of this research is to reveal the attitudes and thoughts about the fence held by local residents living in settlements (borderlanders) in the proximity of a part of the security fence that has already been completed. The research concentrates on the western-Israeli side of the fence, as it aspires to delve into and understand the meaning and implications of the security fence on matters such as personal security, safety of property and freedom of movement, the possibility of maintaining social and economic ties between the two sides and feelings about living in the area in the future. Underlying this research is the transformation occurring in the border area as a result of its closure by construction of the security fence, after many years in which it was open partially. This process has many diverse consequences, some of them contradictory, on the two populations residing near the border in Israel: the majority Jewish population (the national borderlanders), and the minority Arab population (the transnational borderlanders).  相似文献   
33.
Michael C. Ewers 《GeoJournal》2007,68(2-3):119-130
Urban areas compete with one another for people, goods, capital, ideas and other inputs of economic activity. Under the rubric of globalization, instead of only maintaining or improving the initial stock of assets in a city, the power of a place to attract outside flows of economic activity from elsewhere is increasingly important to economic development. Similarly, global or world cities are characterized as the command and control points through which these global economic flows operate. In response to the heightened mobility of highly-skilled labor across national borders, research has begun to examine the role of international human capital as an economic flow. This paper will examine the role of places in determining where the highly-skilled go in the global economy by viewing global city command and control functions as requiring unique labor flows. By reviewing the evidence found in the literature, we can better understand the potential for urban areas to compete for highly-skilled labor in the global economy. Known indicators of place attractiveness are assessed to examine the relationship between the economic trajectories of cities and their labor requirements. Cities are situated between firms and states as the key place-based actors which influence the mobility of highly-skilled labor. Finally, the paper also examines measurement issues and methodological problems in creating indices of world cities as well as explores possibilities for new research.  相似文献   
34.
全球城市理论与中国的国际城市建设   总被引:2,自引:0,他引:2  
吕拉昌 《地理科学》2007,27(4):449-456
全球城市是多因素作用的结果,研究范式由20世纪70年代的马克思主义政治经济学向全球与地区相互作用的范式转换。全球城市体系的划分从单一指标向经济与文化结合的多指标方向发展。但如何选取指标,如何进行指标的测量,如何确定各指标的权重分配以及如何采集城市间相互作用的数据与资料,都是全球城市研究要面对的重要问题。中国的全球城市建设要从全球城市体系的等级、位序规律出发,根据社会经济发展的实际,要有步骤、有目标、分阶段,稳步推进,逐步提升城市发展的层次,促进城市国际化的步伐,建设中国的国际城市。  相似文献   
35.
分形美学以一种新观念和方法研究城市美学,通过建立简单分形模型探讨和度量城市的不规则性和复杂性,使山地城市美学研究从定性走向定量,从模糊走向科学。山地城市与平原城市比较,在地形地貌、空间形态和景观格局等方面表现出了独特的分形美学特征。  相似文献   
36.
In this paper an intervening opportunities model with spatial dominance is developed. The usual assumption in spatial theory is that decision makers are influenced not just by the size of a destination or distance but by these two factors in combination, that is, spatial dominance. Decision-makers will have more knowledge about, and clearly perceive destinations that exert the greatest amount of spatial dominance on their origins, just as they would primate cities. Thus destinations are ranked in terms of the spatial dominance calculated for each destination. Empirical verification of the model utilizes state-to-state migration flow data for the US. Calibration results compare favourably with the traditional intervening opportunities model and the production constrained gravity model. Received: 7 October 1999/Accepted: 15 June 2000  相似文献   
37.
分析了我国城市建设的基本和由此引起的主要环境工程地质问题,研究了现代城市环境工程地质研究的关键技术,并提出了当前我国城市环境工程地质研究亟待解决的关键问题。  相似文献   
38.
The binational cities of Dover and Calais and their region   总被引:2,自引:0,他引:2  
This paper analyses the question of cities that are localised at each part of an international border. We take as an example the two cities of Dover and Calais and look at if they can be considered as binational cities, because they have been recently connected by a tunnel, the ‘fixed link’, and because since 1993, the inner state borders of the European Union have disappeared. It determines firstly if these two towns have been brought closer by the construction of the Channel tunnel and if specific ties are linking these two towns. The article scrutinizes actions taken under INTERREG funds under the general framework of the creation of the ‘Transmanche Region’ and its extension towards a Euroregion to sort out these two cities joint involvement. Finally, it checks if this new area could lead to cross-border activity either for work or tourism and leisure purposes that could conduct the cities of Dover and Calais toward a new type of relationship, premises of a binational city. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
39.
Urban renewal in East African port cities: Mombasa's Old Town waterfront   总被引:3,自引:0,他引:3  
Brian Hoyle 《GeoJournal》2001,53(2):183-197
The urban waterfront redevelopment diaspora, formerly confined to advanced countries, is starting to impact upon coastal settlements in former colonial territories. In diverse contexts ranging from postcolonialism and globalization to cultural revival and tourism development, developing countries are seeking to revive their historic port cities. This paper reports on the experience of Mombasa, Kenya, where waterfront redevelopment is a problematic element in the conservation of the historic urban core, and relates local issues to wider policies, relevant literature and experience elsewhere.  相似文献   
40.
ABSTRACT

Urban areas presently consume around 75% of global primary energy supply, which is expected to significantly increase in the future due to urban growth. Having sustainable, universal energy access is a pressing challenge for most parts of the globe. Understanding urban energy consumption patterns may help to address the challenges to urban sustainability and energy security. However, urban energy analyses are severely limited by the lack of urban energy data. Such datasets are virtually non-existent for the developing countries. As per current projections, most of the new urban growth is bound to occur in these data-starved regions. Hence, there is an urgent need of research methods for monitoring and quantifying urban energy utilization patterns. Here, we apply a data-driven approach to characterize urban settlements based on their formality, which is then used to assess intra-urban urban energy consumption in Johannesburg, South Africa; Sana’a, Yemen; and Ndola, Zambia. Electricity is the fastest growing energy fuel. By analyzing the relationship between the settlement types and the corresponding nighttime light emission, a proxy of electricity consumption, we assess the differential electricity consumption patterns. Our study presents a simple and scalable solution to fill the present data void to understand intra-city electricity consumption patterns.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号