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1.
By using panel data analysis across 368 water utilities in Mexico over the period 2010–2014, we find that small firms are more efficient than medium and large providers and that increasing production is associated with less efficiency. Billing, income collection and profitability are relevant factors to improve efficiency. Medium and large firms require to measure consumption by service with meters in order to increase efficiency, while small firms do not require it.  相似文献   
2.
根据给排水工程专业特点,构造给排水专业的课程体系及其相互关系,制作课程体系信息库并应用Frontpage2000软件将其链接起来,在互联网上供本专业学生查阅,达到了指导、帮助学生综合利用自己所学知识进行课程预习、复习及毕业设计的目的.  相似文献   
3.
国内外水资源承载力的研究综述   总被引:9,自引:0,他引:9  
随着能源危机的出现,资源环境问题逐渐成为各国经济学家和环境学家特别关注的问题.近年来,水资源短缺越来越成为各地经济发展的制约因素,面对这种情况,资源承载力概念的提出为资源与经济发展问题提供了一条新的研究途径.本文将国内外有关水资源承载力概念和量化方法的研究作一总体分析,结果表明:(1)国外对水资源承载力的研究较少,国内的研究大体可分为初始、发展、鼎盛和拓展四个阶段;(2)从横向比较来看,水资源承载力的研究在我国以近十年为盛.但研究多集中在资源学科领域和地理环境学科领域,角度大多是综合考虑多方面的影响因素,对一个地区的水资源承载力作出系统评价,并借助可持续发展的思想,应用已有的和创新的方法来解决水资源承载力的问题;(3)水资源承载力的研究在一定程度上是土地资源承载力研究的进步;(4)水资源承载力的研究较少考虑环境污染对水资源承载力以及整个社会系统的影响.在此基础上,本文最后对承载力在自然资源方面的研究作了小结和展望.  相似文献   
4.
The framework for water accounting is applied to an international river basin, the Orange River Basin, which is shared among Botswana, Namibia, Lesotho and South Africa. Each of the riparian states faces water constraints and relies increasingly on shared international water resources. The countries have adopted the principle of an economic approach to water management, once basin human needs are met, and all but Lesotho have constructed national water accounts to assist in water management. The water accounts for the Orange River Basin bring an economic perspective to water management at the regional level. The accounts include supply and use tables, which are used to compare the contribution to water supply from each riparian state to the amount used. The water accounts are then linked to economic data for each country to calculate water use and productivity by industry and country. There are considerable disparities in water productivity among the countries, which should be taken into account in future decisions about water allocation, pricing and infrastructure development.  相似文献   
5.
6.
Speeding up the environmental protection and construction is one of the major issues in "Greener Olympic Games" held in Beijing in 2008. Making a thorough study to find out the reliable measures to ecological resumption in Beijing has an important scientific and practical significance. It can provide scientific basis for making a better decision for "Greener Olympic Games" held in capital Beijing and development in harmony for society and economy, as well as management for ecological environment. By studying of change of ecological footprint from 1990 to 2003 in Beijing, the paper shows that ecological footprint per capita has a strong relativity with population and GDP, and both of the correlation coefficient between them is about 0.92, as well as the fossil energy land has a position in the lead in ecological footprint items. The study also shows that the ecological capacity per capita in Beijing occupied about 1.25% in global ecological capacity per capita. Began 1990, the ecological deficit in Beijing was about 0.72 hm2, which is at strong unsustainable development at present. Finally, the paper suggests social and economic structure should be adjusted as soon as possible, resources should be strengthen sustainable used and population increasing should be controlled strictly, as well as arable land also should be under control used for built-up areas. Simultaneity, the utilizing ratio of energy sources should be increased, and the consumption of energy sources and ecological deficit in Beijing should be reduced in order to speed up the society and economy development in harmony and sustainment.  相似文献   
7.
虚拟水及其在缓解区域水资源短缺中的应用研究   总被引:1,自引:1,他引:1  
虚拟水是指生产商品和服务所需要的水资源数量。虚拟水战略是指贫水国家或地区通过贸易的方式从富水国家或地区购买水密集型农产品(粮食)来获得本地区水和粮食的安全。本文在综述前人对虚拟水研究的基础上,计算了2002年甘肃省及不同地区主要农产品虚拟水含量,并对甘肃省加强虚拟水贸易的战略进行了探讨。  相似文献   
8.
本文利用生态足迹法对上海市1985~2004年的生态足迹和生态承载力进行了研究,结果表明上海市入均生态足迹和生态承载力分别由1985年的1.9340hm^2、0.1582hm^2逐年增加至2004年的3.0459hm^2、0.5805hm^2,一而同期的入均生态赤字也由1.7958hm^2上升到2.6656hm^2。同时计算了万元GDP生态足迹,并预测了2010年的入均生态足迹和生态承载力。最后得出,上海市入口对自然资源的利用逐年增加,目前已超出了自然生态系统的生态承载力范围,现有的发展模式是不可持续的。  相似文献   
9.
斯蔼  汤洁  王娟  李海毅 《经济地理》2005,25(6):757-760
针对吉林省大安市发展现状和存在的严重生态环境问题,运用生态足迹模型,采用多源数据,首次对大安市生态环境的可持续发展状况进行了定量研究;在此基础上,运用相对指标法对可持续发展的量化结果进行分级。研究表明,2001年大安市的生态需求大于生态供给,生态呈现“供不应求”的局面,人均生态赤字为0.56hm2,处于弱不可持续发展状态。  相似文献   
10.
Assessment of regional trade and virtual water flows in China   总被引:10,自引:0,他引:10  
The success of China's economic development has left deep marks on resource availability and quality. Some regions in China are relatively poor with regards to water resources. This problem is exacerbated by economic growth. Flourishing trade activities on both domestic and international levels have resulted in significant amounts of water withdrawal and water pollution. Hence the goal of this paper is to evaluate the current inter-regional trade structure and its effects on water consumption and pollution via ‘virtual water flows’. Virtual water is the water embedded in products and used in the whole production chain, and that is traded between regions or exported to other countries. For this assessment of trade flows and effects on water resources, we have developed an extended regional input-output model for eight hydro-economic regions in China to account for virtual water flows between North and South China. The findings show that the current trade structure in China is not very favorable with regards to water resource allocation and efficiency. North China as a water scarce region virtually exports about 5% of its total available freshwater resources while accepting large amounts of wastewater for other regions' consumption. By contrast, South China a region with abundant water resources is virtually importing water from other regions while their imports are creating waste water polluting other regions' hydro-ecosystems.  相似文献   
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