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   60241篇
  免费   1721篇
  国内免费   31篇
财政金融   9670篇
工业经济   3921篇
计划管理   8953篇
经济学   12084篇
综合类   970篇
运输经济   373篇
旅游经济   912篇
贸易经济   8584篇
农业经济   2566篇
经济概况   6482篇
水利工程   7376篇
邮电经济   102篇
  2021年   455篇
  2020年   687篇
  2019年   952篇
  2018年   1390篇
  2017年   1389篇
  2016年   1317篇
  2015年   892篇
  2014年   1357篇
  2013年   5785篇
  2012年   1919篇
  2011年   1983篇
  2010年   1551篇
  2009年   1686篇
  2008年   1932篇
  2007年   1947篇
  2006年   1705篇
  2005年   1644篇
  2004年   1624篇
  2003年   1247篇
  2002年   1161篇
  2001年   1156篇
  2000年   1164篇
  1999年   983篇
  1998年   1016篇
  1997年   1002篇
  1996年   965篇
  1995年   910篇
  1994年   941篇
  1993年   982篇
  1992年   947篇
  1991年   938篇
  1990年   850篇
  1989年   739篇
  1988年   706篇
  1987年   705篇
  1986年   705篇
  1985年   1013篇
  1984年   1019篇
  1983年   1015篇
  1982年   970篇
  1981年   925篇
  1980年   863篇
  1979年   894篇
  1978年   729篇
  1977年   668篇
  1976年   601篇
  1975年   506篇
  1974年   487篇
  1973年   460篇
  1972年   346篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Consumers act out roles throughout their lives. Marketers assist in this role playing by providing the wardrobes, props, and sets in the form of products and services. They also help people understand acceptable role behavior by portraying roles in their communication programs. Consumers assume new roles as they age. This article is designed to enhance understanding of the often-ignored roles that accompany aging and provides examples of and suggestions for effective marketing for these role transitions.  相似文献   
102.
The introduction of traffic management schemes has been one response of the National Parks to the problem of ever-increasing car-borne visitors and the consequent damage caused to the rural environment. By reviewing these schemes and by determining and explaining attitudes towards one particular traffic management experiment, the paper aims to deduce lessons for future policy. The analysis, based on two visitor surveys, suggests that the likelihood of success is improved when schemes are integrated, containing both ‘carrot’ and ‘stick’ elements. Since public perceptions are also found to be pivotal to its success, appropriate marketing of a scheme is vital. The paper concludes, however, that to achieve the fundamental objective of greater accessibility with less mobility, a more wide-ranging marketing effort is required intended to engender a sea change in attitude towards both the car and public transport.  相似文献   
103.
104.
105.
Linear and nonlinear Granger causality tests are used to examine the dynamic relation between daily Dow Jones stock returns and percentage changes in New York Stock Exchange trading volume. We find evidence of significant bidirectional nonlinear causality between returns and volume. We also examine whether the nonlinear causality from volume to returns can be explained by volume serving as a proxy for information flow in the stochastic process generating stock return variance as suggested by Clark's (1973) latent common-factor model. After controlling for volatility persistence in returns, we continue to find evidence of nonlinear causality from volume to returns.  相似文献   
106.
Futures research includes the problem of generating reasonably exhaustive and plausible scenarios for a given topic, a problem for which there are no truly satisfactory solutions. This article reviews and evaluates a method, field anomaly relaxation, first put forward some 20 years ago. The evaluation is in the context of an illustrative study of political developments in Europe. The research reconstructs and further develops the method and concludes that it has something to offer for scenario generation. Its weaknesses are identified and suggestions for further research are made.  相似文献   
107.
108.
This paper compares the approximation capabilities of the minflex-Laurents translog and minflex generalized Leontief cost functions with their translog and generalized Leontief counterparts in Monte Carlo experiments. The minflex Laurent specifications generally provided closer approximations to underlying technical and economic parameters. Imposition of nonlinear restrictions on some of the parameters of the minflex Laurent models yielded measurable improvement in estimated elasticities of substitutions, returns to scale, and rates of technical change.The refereeing process of this paper was handled through E. Appelbaum.  相似文献   
109.
Analyzing synthetic cohorts in the 1980 and 1990 Public Use Microdata Samples, we find that Mexican‐Americans and other Hispanics acquired English fluency at a faster pace than Puerto Ricans and Cuban‐Americans during the 1980s. Additional results indicate that English‐skill investments differently influenced the earnings distributions of these ethnic groups.  相似文献   
110.
Intensive fertilizer use has led to nitrate contamination of groundwater in many areas. This article examines the possibility of removing nitrates through the construction of artificial wetlands. A pilot study conducted in Denmark has found that the method is effective and economical, at least for small waterworks, though further treatment is necessary before an acceptable microbiological water quality is attained.  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