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   37521篇
  免费   1043篇
财政金融   6785篇
工业经济   2627篇
计划管理   6378篇
经济学   8873篇
综合类   708篇
运输经济   325篇
旅游经济   587篇
贸易经济   6133篇
农业经济   1797篇
经济概况   4261篇
信息产业经济   3篇
邮电经济   87篇
  2023年   207篇
  2021年   260篇
  2020年   511篇
  2019年   778篇
  2018年   916篇
  2017年   1009篇
  2016年   903篇
  2015年   633篇
  2014年   960篇
  2013年   4230篇
  2012年   1223篇
  2011年   1268篇
  2010年   1153篇
  2009年   1201篇
  2008年   1160篇
  2007年   954篇
  2006年   895篇
  2005年   826篇
  2004年   713篇
  2003年   752篇
  2002年   691篇
  2001年   782篇
  2000年   768篇
  1999年   639篇
  1998年   713篇
  1997年   672篇
  1996年   634篇
  1995年   586篇
  1994年   587篇
  1993年   588篇
  1992年   598篇
  1991年   595篇
  1990年   540篇
  1989年   415篇
  1988年   416篇
  1987年   420篇
  1986年   404篇
  1985年   582篇
  1984年   623篇
  1983年   564篇
  1982年   511篇
  1981年   532篇
  1980年   493篇
  1979年   495篇
  1978年   404篇
  1977年   353篇
  1976年   338篇
  1975年   283篇
  1974年   277篇
  1973年   270篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
131.
132.
133.
The extra vulnerability of industrializing countries to environmental problems and industrial accidents cannot be understood or solved by a ‘normal’ scientific analysis. Aspects of the social and institutional context must be included, through analyses based on post-normal science. The standard two-dimensional classification of PNS is modified to have axes ‘social ‘and institutional vulnerabilities’ and ‘complexity of technological hazards’. The analysis is mainly applied to the case of the relatively rare accidents with catastrophic potential. In these, the deaths per accident in India, Mexico and Brazil are much greater than in the industrialized countries. This discrepancy arises partly from location of such plants near residential communities for marginalized workers and their families. Other socio-political factors are relevant, as the role of these countries in the global production system, the enforcement of safety and planning laws, quality of housing, and lifestyle of residents. Reducing the vulnerability of industrializing countries will therefore require major social policies and a comprehension of the limits of the normal scientific and economic approaches to such problems.  相似文献   
134.
This study analyzes the effects of an important postderegulation innovation on rail freight productivity: the elimination of cabooses and related crew members. It also analyzes the overall growth of productivity in rail freight between 1983 and 1997 (using a translog rail cost function estimated over a sample of Class I railroads between 1983 and 1997). The results indicate that elimination of cabooses and associated crew members from freight trains reduced costs by 5-8% on the typical Class I railroad in 1997, equivalent to an annual cost saving of $2 billion to $3.3 billion for all Class I railroads. Moreover, if Class I railroads had no other technological advances since 1983, their 1997 costs (with 1997 factor prices) would have been 36-43% higher than they in fact were. Finally, the results show that overall productivity growth in rail freight did not decelerate between 1983 and 1997; if anything, it accelerated slightly.  相似文献   
135.
136.
A statistically optimal inference about agents' ex ante price expectations within the US broiler market is derived using futures prices of related commodities along with a quasi‐rational forecasting regression equation. The modelling approach, which builds on a Hamilton‐type framework, includes endogenous production and allows expected cash price to be decomposed into anticipated and unanticipated components. We therefore infer the relative importance of various informational sources in expectation formation. Results show that, in addition to the quasi‐rational forecast, the true supply shock, future prices, and ex post commodity price forecast errors have, at times, been influential in broiler producers' price expectations. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
137.
above the certainty level while for additive uncertainty the price should be lower than the certainty level. This note gives an intuitive explanation for the result after first presenting a parsimonious review of the two models. We also discuss which, if either, of the two models is more realistic. Received December 14, 2001; revised version received July 16, 2002 Published online: April 30, 2003 We thank referees for helpful comments. Ciaran Driver would like to acknowledge the research facilities from ANU, Canberra for their help in writing this paper.  相似文献   
138.
139.
The Amazon is the largest tropical forest area on Earth, and has been undergoing rapid deforestation for the last four decades. In the Brazilian Amazon, large‐scale pasture for cattle ranching and soybean production are the main land uses, leading to a yearly deforestation rate of 0.5%. These conversions are mostly located in frontier areas distributed along the so‐called “arc of deforestation”. Within this large zone, various land use change processes are interacting through several modes of land valuation and organisation. From several case studies in the State of Pará (Brazil), the current project aims at analysing how landscape dynamics are related to infrastructure development, ecological conditions, zoning policies and to the evolution and the organisation of the production, consumption and marketing chains of livestock products. This paper presents the results for one test site, the region of São Félix do Xingú, South of Pará This region is the focus of land speculation, cattle expansion, and deforestation. Road construction, investments in electrical energy, financial credit for cattle, and the land reform policies have all fuelled this process. All these factors make this region one of the most dynamic agricultural frontiers in the Brazilian Amazon. The main objective of the paper is to improve our understanding of deforestation processes by crossing spatial analyses and 1ivestock economics.studies, and to characterise the role and impact of various natural and anthropic factors in the location and development of the main types of farmers, and their policy implications.  相似文献   
140.
We evaluate the appropriateness of regulation within the Canadian cable television industry by applying both parametric and non-parametric approachesto measure scale efficiency. Although we begin with a sample offering adequatedegrees of freedom for parametric estimation, important policy issues lead us toconsider further estimation over sub-samples. Since some of these sub-samplesare small enough that parametric models cannot guarantee reliable estimates, weobtain production characteristics non-parametrically through data envelopmentanalysis. The nonparametric results for scale efficiency support the parametricresults. We find evidence against a natural monopoly argument that might havejustified continuation of the mandated monopolization of Canadian cable televisionservice. By the end of the sample period, there were no longer substantial economiesof scale in most relevant markets.  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