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   39473篇
  免费   625篇
财政金融   6684篇
工业经济   2358篇
计划管理   6455篇
经济学   9235篇
综合类   686篇
运输经济   178篇
旅游经济   345篇
贸易经济   8161篇
农业经济   1151篇
经济概况   4161篇
信息产业经济   47篇
邮电经济   637篇
  2023年   112篇
  2021年   152篇
  2020年   289篇
  2019年   464篇
  2018年   2779篇
  2017年   2561篇
  2016年   1752篇
  2015年   441篇
  2014年   675篇
  2013年   2504篇
  2012年   1223篇
  2011年   2724篇
  2010年   2458篇
  2009年   2244篇
  2008年   2182篇
  2007年   2447篇
  2006年   681篇
  2005年   906篇
  2004年   938篇
  2003年   1060篇
  2002年   686篇
  2001年   571篇
  2000年   512篇
  1999年   423篇
  1998年   494篇
  1997年   427篇
  1996年   440篇
  1995年   364篇
  1994年   384篇
  1993年   359篇
  1992年   369篇
  1991年   390篇
  1990年   349篇
  1989年   260篇
  1988年   266篇
  1987年   272篇
  1986年   265篇
  1985年   364篇
  1984年   358篇
  1983年   335篇
  1982年   289篇
  1981年   289篇
  1980年   285篇
  1979年   277篇
  1978年   228篇
  1977年   187篇
  1976年   184篇
  1975年   163篇
  1974年   152篇
  1973年   149篇
排序方式: 共有10000条查询结果,搜索用时 968 毫秒
161.
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   
162.
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   
163.
164.
165.
166.
An algorithm is described to compute equilibria of the general economic model with incomplete asset markets, that is, of GEI. The algorithm is based on the existence of a route of zeros of a homotopy whose domain includes the price simplex and a Grassmann Manifold. This route is followed, in effect, by localizing and following diffeomorphic pieces in Euclidean space, and by relocalizing as is necessary.  相似文献   
167.
168.
169.
A new physical infrastructure to support activities based on communications and the transmission of information is being developed. Part of this infrastructure includes the construction of ‘intelligent’ buildings which are seen to play as important a role in improving efficiency of office workers as automation has played on the shopfloor of manufacturing industry. The location of these buildings is important. This article focuses on two types of experimental office development—neighbourhood offices and resort offices.  相似文献   
170.
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