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   19360篇
  免费   193篇
财政金融   3002篇
工业经济   864篇
计划管理   3146篇
经济学   4677篇
综合类   487篇
运输经济   87篇
旅游经济   75篇
贸易经济   5047篇
农业经济   102篇
经济概况   1449篇
信息产业经济   44篇
邮电经济   573篇
  2023年   61篇
  2022年   45篇
  2021年   59篇
  2020年   120篇
  2019年   138篇
  2018年   2447篇
  2017年   2266篇
  2016年   1364篇
  2015年   207篇
  2014年   231篇
  2013年   677篇
  2012年   589篇
  2011年   2032篇
  2010年   1942篇
  2009年   1608篇
  2008年   1582篇
  2007年   1921篇
  2006年   130篇
  2005年   436篇
  2004年   504篇
  2003年   585篇
  2002年   285篇
  2001年   88篇
  2000年   85篇
  1999年   23篇
  1998年   22篇
  1997年   11篇
  1996年   19篇
  1995年   12篇
  1994年   4篇
  1993年   5篇
  1992年   7篇
  1991年   3篇
  1988年   1篇
  1986年   13篇
  1985年   2篇
  1984年   2篇
  1983年   4篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
  1978年   2篇
  1977年   3篇
  1976年   4篇
  1975年   1篇
  1973年   1篇
  1970年   1篇
  1968年   1篇
  1939年   1篇
排序方式: 共有10000条查询结果,搜索用时 953 毫秒
111.
112.
113.
114.
Lejeune  Miguel A. 《NETNOMICS》2002,4(2):145-162
Denial of Service (DoS) attacks consist of overwhelming a server, a network or a Web site in order to paralyze its normal activity. The additional parameter in Distributed Denial of Service (DdoS) attacks is the distributing strategy. It means that DDoS attacks do not come from a single computer but stem from all accessible channels and servers. Consequences are multiple, ranging from system errors, temporary inability to access the Web site for normal users to challenging the actual reliability of the Internet. Despite this, Internet users show carelessness. The explanation lies in the specificities of DDoS attacks. We explore possibilities to raise users' awareness about the actual amplitude of problems caused by DDoS attacks. We suggest a careful examination of Internet pricing mechanisms and switching from flat to usage-constraining pricing schemes.  相似文献   
115.
UK high street banks are continuing to extend the choice of channel through which customers can manage their moneycolon; an obvious example is e-banking. They have been keen to exploit technological advances and changing customer attitudes to alternative channels. Additionally, competition from leaner new market entrants has provided an added incentive to adopt new approaches. In the light of such developments, it is worth reflecting on the changing nature of the bank–customer relationship. This paper suggests that banks are finding it difficult to manage relationships effectively due, in large measure, to the sheer volume of customer data generated by new interactive, technology-based channels. Paradoxically, it seems that the more data banks have about customers the less likely they are to know them on a personal level. It is further suggested that channels such as e-banking potentially reduce the level of personal contact between bank and customer to the extent that a ‘virtual’ relationship develops. This paper concludes that, given the tendency towards ‘virtualisation’, it is inconceivable that bank–customer relationships will become any more intimate in the future. Indeed, a greater degree of personalisation in customer communication may be the very best that banks are able to offer.  相似文献   
116.
117.
118.
A bilinear multivariate errors-in-variables model is considered. It corresponds to an overdetermined set of linear equations AXB=C, A∈ℝm×n, B∈ℝp×q, in which the data A, B, C are perturbed by errors. The total least squares estimator is inconsistent in this case.  An adjusted least squares estimator is constructed, which converges to the true value X, as m →∞, q →∞. A small sample modification of the estimator is presented, which is more stable for small m and q and is asymptotically equivalent to the adjusted least squares estimator. The theoretical results are confirmed by a simulation study. Acknowledgements. We thank two anonymous reviewers for their suggestions and corrections.? A. Kukush is supported by a postdoctoral research fellowship of the Belgian office for Scientific, Technical and Cultural Affairs, promoting Scientific and Technical Collaboration with Central and Eastern Europe.? S. Van Huffel is a full professor with the Katholieke Universiteit Leuven.? I. Markovsky is a research assistant with the Katholieke Universiteit Leuven.? This paper presents research results of the Belgian Programme on Interuniversity Poles of Attraction (IUAP V-22), initiated by the Belgian State, Prime Minister's Office – Federal Office for Scientific, Technical and Cultural Affairs of the Concerted Research Action (GOA) projects of the Flemish Government MEFISTO-666 (Mathematical Engineering for Information and Communication Systems Technology), of the IDO/99/03 project (K.U. Leuven) “Predictive computer models for medical classification problems using patient data and expert knowledge”, of the FWO projects G.0078.01, G.0200.00, and G0.0270.02.? The scientific responsibility is assumed by its authors.  相似文献   
119.
120.
This study examines the effect of initiating discount and no discount dividend reinvestment plans on shareholder wealth. The results show a negative response to DRP announcements, which is significantly smaller than that found in studies of new equity offerings. These results are consistent with the Scholes and Wolfson (1989) hypothesis that managers in need of equity capital use DRPs to mitigate the adverse stock price effects of new equity issue announcements. Furthermore, there is a significant difference in the price response of discount and no discount DRPs for industrial firms. This result is supportive of the signaling potential of discount DRPs. Supportive evidence is also found in the analysis of firm characteristics for industrial firms.  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