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   20516篇
  免费   498篇
  国内免费   334篇
财政金融   1259篇
工业经济   1153篇
计划管理   5384篇
经济学   3393篇
综合类   2115篇
运输经济   351篇
旅游经济   714篇
贸易经济   2700篇
农业经济   1938篇
经济概况   2341篇
  2024年   92篇
  2023年   332篇
  2022年   361篇
  2021年   521篇
  2020年   714篇
  2019年   507篇
  2018年   483篇
  2017年   673篇
  2016年   597篇
  2015年   652篇
  2014年   1557篇
  2013年   1952篇
  2012年   1702篇
  2011年   2102篇
  2010年   1512篇
  2009年   1299篇
  2008年   1373篇
  2007年   1226篇
  2006年   1005篇
  2005年   779篇
  2004年   548篇
  2003年   322篇
  2002年   210篇
  2001年   189篇
  2000年   142篇
  1999年   82篇
  1998年   92篇
  1997年   56篇
  1996年   50篇
  1995年   45篇
  1994年   36篇
  1993年   20篇
  1992年   19篇
  1991年   18篇
  1990年   9篇
  1989年   8篇
  1988年   5篇
  1987年   4篇
  1986年   9篇
  1985年   11篇
  1984年   12篇
  1983年   10篇
  1982年   7篇
  1981年   1篇
  1980年   2篇
  1979年   2篇
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
981.
The notion of the knowledge-based economy highlights the strategic importance of inter-industrial knowledge flows. Among others, the crucial role of information and communications technology (ICT) industry is emphasized. The pattern whereby technological knowledge is created, accumulated and disseminated through the interactive learning among industries can be portrayed as a network. Based on the network theory, this empirical study analyses, from the dynamic perspective, inter-industrial technological knowledge structure of Korean industries during the reference period of early 1980s to mid-1990s. Overall, the density of the network increased over time, implying that the knowledge network has expanded and intensified. The role of the ICT industry in the global network has also increased but needs to be further strengthened, especially informatization of non-ICT industries by the outflow of ICT industrial knowledge in the future. The findings in turn render some important policy implications that should be addressed in developing technology policy.  相似文献   
982.
We present a dynamic model of the indigenous natural gas industry in the UK. The model has been built using a system dynamics approach. Using the model several scenarios have been analyzed. We found that management of the supply-side policy alone cannot substantially postpone the discovery, production and consumption peak. We also found that the dynamics of the main variables, namely, exploration, production and consumption, are sensitive to initial demand conditions. Postponing the onset of gas price increases can therefore be achieved more effectively through efforts to reduce demand growth. One might expect that a low taxation policy would encourage more exploration and production of gas and thereby stimulate higher consumption rates. Instead, there was no overall net effect on production and consumption in the long term. The depletion effect on cost of exploration acts as counterbalance to low taxation policy. Depletion effect causes cost and thus price to rise further which depress consumption rate. The advances in exploration and production technology can delay the peak of exploration, production and consumption. Technological improvements mean lower cost of exploration and production which pressure down the long-term pattern of price dynamics.  相似文献   
983.
In order to deal with growing uncertainties emerging in the 3G wireless industry and to preserve their competitiveness, managers involved in the wireless value network should identify future success very early and develop their strategic planning on time. This study, based on a Scenario Evaluation and Analysis through Repeated Cross impact Handling, allows the generation of both qualitative and quantitative scenarios and can be used as an operative planning tool. The dynamic forces driving the scenario are based on the main principles of system thinking and multiple features. The probabilistic data have been elicited with the help of 40 executives in USA and Europe working for companies in the different phases of the wireless value chain. Findings allow to identify basic trends and uncertainties useful to develop corporate or business strategies.  相似文献   
984.
Despite its worldwide success, the innovation systems approach is often criticised for being theoretically underdeveloped. This paper aims to contribute to the conceptual and methodological basis of the (technological) innovation systems approach. We propose an alteration that improves the analysis of dynamics, especially with respect to emerging innovation systems. We do this by expanding on the technological innovation systems and system functions literature, and by employing the method of ‘event history analysis’. By mapping events, the interactions between system functions and their development over time can be analysed. Based on this it becomes possible to identify forms of positive feedback, i.e. cumulative causation. As an illustration of the approach, we assess the biofuels innovation system in The Netherlands as it evolved from 1990 to 2007.  相似文献   
985.
This paper examines the potential of integrating future-oriented technology analysis (FTA) with risk assessment methodologies and tools, with the aim of developing more proactive risk assessments and also systematically including risk assessment in future-oriented technology analysis. The similarities and development challenges of foresight, Technology Analysis (TA) and risk assessment methodologies are discussed in the light of the empirical material gathered from projects performed at VTT. Among the projects are IRRIIS project focusing on risk assessment of critical infrastructures, INNORISK project aiming at managing opportunities, risk and uncertainties in new business creation and a project related to the climate change (CES). The case projects are positioned according to their important design dimensions (informative vs. instrumental outcomes; consensual vs. diverse future perspectives, extensive vs. exclusive stakeholder involvement, and autonomous vs. fixed management). The common and complementary features of FTA and risk assessment are discussed, suggesting new ways to evolve the modular design when integrating FTA and risk assessment methodologies and tools.  相似文献   
986.
Decomposition of energy-related CO2 emission over 1991-2006 in China   总被引:8,自引:0,他引:8  
This paper presents a decomposition analysis of energy-related CO2 emission in China for the period 1991-2006 divided into three equal time intervals. The complete decomposition method developed by Sun is used to analyze the nature of the four factors: CO2 intensity, energy intensity, structural changes and economic activity. The results show that economic activity has the largest positive effect in CO2 emission changes in all the major economic sectors and China has achieved a considerable decrease in CO2 emission mainly due to the improved energy intensity. However, the impact of CO2 intensity and structural changes is relatively small. Structural changes only exhibit positive effect to the CO2 mitigation in agricultural sector, and CO2 intensity also contributes to the decrease of CO2 emission in transportation sector. Moreover, a formula about CO2 mitigation is presented in this paper, which shows that China has made a significant contribution to reducing global CO2 emission.  相似文献   
987.
This research analyzes amenity values of spatial configurations of forest landscapes over space and time in the Southern Appalachian Highlands using geographically weighted regression (GWR) in a hedonic housing-price framework with a census-block group (CBG) dataset. Results show that housing-price response to mean forest-patch size and forest-patch density increased substantially between 1990 and 2000 in a few specific areas with economically significant amenity values. The spatial and temporal dynamics of the resulting amenity-value estimates are evaluated for potential use as site-selection indicators for implementation of forest conservation programs.  相似文献   
988.
This paper presents a basin scale analysis of the Nilüfer River Basin of Turkey, where agricultural, urban, and environmental users compete for scarce water in an environment where climate change and food security present large and growing challenges. It presents results of a basin scale dynamic nonlinear programming model that addresses economic efficiency, climate change, and food security. Its approach can be applied to other water-stressed regions operating in environments of economic and hydrologic constraints on water use. Basin scale modeling approach provides a general framework for formulating water management policies, consistent with the principles underlying the European Union Water Framework Directive.  相似文献   
989.
李永强  冯淑慧 《技术经济》2020,39(9):82-88,100
旅游业可以带动县域经济的发展,但也要依靠一定程度的经济作为基础支撑,如何协调好两者的均衡发展,关系到旅游产业与县域经济的耦合协调问题。以阳朔县为研究对象,采用协整分析、误差修正模型以及耦合协调度分析的方法对2004年至2018年阳朔县旅游产业和经济的关系和耦合协调性进行研究。结果表明:旅游产业和经济之间存在长期均衡的关系,经济的短期波动受旅游产业的短期波动以及误差修正项的影响;旅游产业和经济在观测期间由轻度失调逐渐转变为良好协调的状态。  相似文献   
990.
ABSTRACT

The implications of national or regional energy policies for technical efficiency and environmental outcomes in electricity generation depend on fossil fuel input substitution. This study uses state level data to examine fossil fuel (coal and natural gas) substitution in electricity generation under increased availability of natural gas in the United States. We observe that changes in elasticities of substitution from pre-2009 to post-2009 differ across states suggesting that the effects of increased availability of inexpensive natural gas on electricity generation have been spatially heterogeneous. We rely on the observed heterogeneity to assess the effects of fossil fuel input substitution on technical efficiency and CO2 emissions. The results reveal that state level elasticity of substitution between natural gas and coal has a positive effect on technical efficiency and a negative effect on CO2 emissions. Therefore, future policy design and analyses should reflect the implications for regional elasticities of fossil fuel substitution and associated environmental outcomes.  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