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   909篇
  免费   89篇
  国内免费   53篇
测绘学   31篇
大气科学   99篇
地球物理   55篇
地质学   235篇
海洋学   108篇
综合类   85篇
自然地理   438篇
  2024年   2篇
  2023年   7篇
  2022年   35篇
  2021年   46篇
  2020年   25篇
  2019年   31篇
  2018年   31篇
  2017年   63篇
  2016年   45篇
  2015年   44篇
  2014年   58篇
  2013年   39篇
  2012年   45篇
  2011年   44篇
  2010年   34篇
  2009年   30篇
  2008年   34篇
  2007年   42篇
  2006年   44篇
  2005年   23篇
  2004年   23篇
  2003年   41篇
  2002年   31篇
  2001年   33篇
  2000年   28篇
  1999年   23篇
  1998年   25篇
  1997年   28篇
  1996年   18篇
  1995年   19篇
  1994年   14篇
  1993年   8篇
  1992年   7篇
  1991年   9篇
  1990年   3篇
  1989年   9篇
  1988年   1篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1982年   2篇
  1980年   1篇
排序方式: 共有1051条查询结果,搜索用时 562 毫秒
241.
Marton  A 《地理科学》1997,17(1):8-17
在东北亚区域发展方向论述了经济快速增长,资源转移和区域贸易格局的特点,随着后分析了图们江地区开发的国际环境以及图们江发展计划,指出图们江开发的几种可能选择和图们江与东北亚经济协作前景,特别提出加强国与国之间的贸易具有重要意义。  相似文献   
242.
长江经济带创新产出的空间特征和时空演化   总被引:1,自引:0,他引:1  
本文以县(市、区)作为空间分析单元,以专利授权量作为创新产出指标,对1986-2014年长江经济带853个县域创新产出的时空特征进行ESDA分析。结果发现:①长江经济带创新产出的绝对差异在2001年前增长缓慢,其后增长迅猛,2012年后开始降低;相对差异呈现“增加—缩小—缓慢增加—缩小”的态势,其年度空间关联性呈增长趋势;②长江经济带创新产出县域分布呈现出分散、集中、相对集中扩散的态势,创新产出较高的县(市、区)为长三角地区地级市区、经济发达县(市、区)以及中西部地区省会城市市区;③显著空间关联类型总体格局稳定,局部变化明显,县(市、区)显著空间的关联类型以正相关类型为主,显著低低集聚关联类型占主导地位,低低集聚地区主要在西部地区,且有向中部扩展的态势;④长江经济带创新产出空间格局演变过程中,科技创新资源禀赋、教育水平与研发投入、技术溢出与扩散、政策与制度因素的作用较为显著。  相似文献   
243.
This paper highlights the tension between advocacy for ‘Blue growth’ in maritime policy and efforts to safeguard future economic growth via the Marine Strategy Framework Directive. In 2015, policy-makers withdrew three of four proposed Marine Conservation Zones (MCZs) in the Irish Sea from consideration for designation, due to concerns that they could significantly impact on the fisheries sector in Northern Ireland because they overlap with prawn fishing grounds in the Irish Sea. Although research has quantified the potential impact upon fishing vessels, none has quantified the impact upon the fisheries sector nor assessed the significance of this impact. Arguably, MCZ designations (or lack thereof) based on the ‘significance’ of an impact require robust underpinning evidence. This paper reports the findings of an Economic Impact Assessment, which has quantified the impact of a decline in landings upon the Northern Ireland fisheries sector and regional economy (data which is currently absent from the evidence base for the MCZ designation process in England). It finds that this will incur job losses in three fishing ports in Northern Ireland, but is unlikely to have a significant impact upon Northern Ireland's fisheries sector and regional economy in terms of jobs and Gross Value Added (GVA). In the worst case, the resulting economic impact is a decrease of £1.05–1.12 m/year GVA in Northern Ireland, which is 1.1% of the contribution of fishing and fish processing to the regional economy. Economic significance assessments, using this methodology, may be useful in supporting the evidence base underpinning MCZ designation and other aspects of marine planning.  相似文献   
244.
China has achieved a long-term and high-speed growth in terms of national economy, but faces a series of highlighted problems concerning economic growth and resource and environment support. This paper summarizes the progress of research on economic growth and its support system (resource and environment) mainly from the perspective of geography, and puts forward the main research direction of the support system for economic growth in future.  相似文献   
245.
Fisheries resources play a major role in the national economy and to food security in Solomon Islands. Climate change is likely to have a substantial impact on fish production that can lead to a fragile food security condition in the country. This paper assesses the potential economic impact of three important climate change adaptation strategies – natural resource management (NRM), fish aggregating devices (FAD) and aquaculture – in Solomon Islands. The study used a country-specific partial equilibrium economic model with six fish sub-sectors and analyzed potential impact of alternate climate change adaptation strategies for 2035 and 2050. The modeling and scenario analyses show that total fish demand is likely to surpass domestic fish production in 2050. Without appropriate climate adaptation strategy, per capita consumption of domestically produced fish will decline, which has serious negative food security implications for the country. The economic (welfare) analysis conducted based on modeling results show that the national level net economic gains due to climate change adaptation strategies are substantial. If cost and topographic conditions permit, low-cost inshore FADs are expected to be a good mechanism for augmenting domestic supplies of tuna and similar species in Solomon Islands.  相似文献   
246.
Successive marine policies set by the European Union identify the maritime sectors as crucial drivers for growth and jobs in the EU economy. The design of marine policies and the assessment of the importance of the maritime economy need empirical support that provides the basic data to help the decision-making process. This paper proposes a metric, in the form of a synthetic index, to measure and compare the importance of the maritime sectors in the European Atlantic area. The index scores can be used to assess the position of each Atlantic region so that it is possible to compare its performance to the rest of the area. The results show the relative weight of the maritime sectors in the European Atlantic regions and the high heterogeneity among them. Analyzing the maritime economy with this index can provide guidance for the design of economic policies to identify and revitalize the regions with greater potential for Blue Growth in the Atlantic area. This may help to put into perspective the importance of the maritime economy and can serve to improve the socio-economic dimension of the use of marine waters.  相似文献   
247.
In this study we examine the impact of large-scale natural disasters on economic development. A major obstacle in exploring this relationship is the poor data quality on GDP per capita in low-income countries, while at the same time more than 90% of all disasters that happen worldwide occur in these particular countries. To overcome this problem, we use data based on satellite images of the night-time light intensity in a specific country or region which is shown to be highly correlated with income per capita. After testing for the sensitivity of the results, our main findings suggest that natural disasters reduce the amount of lights visible from outer space significantly in the short run. To be more precise, we demonstrate that climatic and hydrological disasters cause a large drop in the luminosity in developing and emerging market countries, while geophysical and meteorological disasters decrease light intensity more in industrialized countries. It turns out that using reported real GDP per capita figures underestimates the true impact. Besides, a large part of the economic consequences of the natural events is explained by their regional impact. However, in the long run most of the disaster effect has disappeared. Finally, the impact of a disaster depends partly on the size and scope of the natural catastrophe, the geographical location, the degree of financial development of a country and the quality of the political institutions present.  相似文献   
248.
Taking a global perspective this paper sets out to theoretically and empirically identify prosperity patterns for four groups of countries at different levels of economic development. It conceptualizes ‘prosperity’ in terms of ecological sustainability, social inclusion, and the quality of life and contextualizes this definition in global perspective. Subsequently, it operationalizes and measures these dimensions on the basis of data from sources such as the World Bank, the Global Footprint Network and the OECD for 138 countries and by applying dual multiple factor analysis. Building on earlier research that suggested that higher development levels in terms of GDP per capita are capable of providing social and individual prosperity but at the expense of environmental sustainability, we ask whether other interrelations between prosperity indicators exist on other levels of economic development. Empirically distinguishing between ‘rich’, ‘emerging’, ‘developing’ and ‘poor countries’ the paper finds that social and individual prosperity indicators largely increase with economic development while ecological sustainability indicators worsen. Our analyses further reveal that ‘social cohesion’ can be established under different economic and institutional conditions, that subjective wellbeing increases with income rises at all levels of economic development and that a decoupling of carbon emissions from the provision of prosperity is, in principle, achievable, while a reduction of the global matter and energy throughput poses a much greater challenge. The paper concludes by highlighting the repercussions of these findings for the trajectories that countries at different levels of economic development would need to undertake.  相似文献   
249.
How much are Chinese people and various citizen groups concerned about the environment relative to other major public problems? What are the key factors and to what extent do these factors shape individual Chinese environmental concern? Based on a micro-macro model and a county fixed model proposed in this study, we employ nationwide representative public opinion survey data and provincial statistics to examine the determinants and variations of public environmental concern in China. The data shows that environmental concern is not among the top-ranked issue concerns in China overall, but in the urban areas and in the east-coastal region environmental protection features as a rather important issue. Our regression analyses further demonstrate that the Chinese environmental concern is significantly affected by both micro-level socio-demographic variables and macro-level regional economic conditions and environmental risks. In the east-coastal region, such individuals as urbanites with high income are most environmentally concerned. There is a lack of concern over environmental issues among the public in the west region, where little association between individual sociodemographics and their environmental concern is detected. In the central-northeast region, education effect is evident in the rural area. Location contextual factors such as economic development and environmental risk account for most of the observed variations in public environment concern.  相似文献   
250.
长江经济带经济-环境协调发展格局及演变   总被引:8,自引:6,他引:2  
邹辉  段学军 《地理科学》2016,36(9):1408-1417
通过经济与环境系统的协调发展度评估,分析了长江经济带经济环境协调发展的时空演变格局,并对经济带经济发展、环境污染与环境质量的格局与态势展开探讨。研究表明:经济带协调发展度空间差异显著,东部地区明显大于中西部地区,沿江地区高于非沿江地区。高度协调型主要分布在长三角地区及少数中西部省会城市;高度失调型主要分布在重庆、皖北、滇西南、鄂中等地区;江西与四川是协调型转为失调型的集中地区。长三角核心城市经济地位依然凸显,但长三角边缘地区城市经济位序呈下降趋势,中西部地区部分城市经济位序上升明显。工业废水排放以重庆、苏州、杭州为最多,工业SO2排放呈现3大集中地带。城市空气质量较差的是长三角边缘地区以及中西部沿江地区,城市空气质量总体上与工业SO2排放、工业烟尘排放在空间格局上较为吻合。长江干流断面水质上游(川滇渝)与下游(苏沪)较差,一定程度上反映了沿江地区工业废水排放对长江水质的影响。最后,从树立发展与保护双重使命,创新经济带开发体制机制;推进下游城市经济转型升级,培育中上游新的经济增长极;落实最严格的管理制度,共建生态文明示范带等方面提出发展建议。  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