全文获取类型
收费全文 | 30907篇 |
免费 | 297篇 |
专业分类
财政金融 | 5373篇 |
工业经济 | 1810篇 |
计划管理 | 4711篇 |
经济学 | 6884篇 |
综合类 | 980篇 |
运输经济 | 88篇 |
旅游经济 | 209篇 |
贸易经济 | 6485篇 |
农业经济 | 694篇 |
经济概况 | 3345篇 |
信息产业经济 | 45篇 |
邮电经济 | 580篇 |
出版年
2021年 | 72篇 |
2020年 | 146篇 |
2019年 | 213篇 |
2018年 | 2575篇 |
2017年 | 2355篇 |
2016年 | 1489篇 |
2015年 | 265篇 |
2014年 | 366篇 |
2013年 | 1504篇 |
2012年 | 780篇 |
2011年 | 2402篇 |
2010年 | 2165篇 |
2009年 | 1859篇 |
2008年 | 1909篇 |
2007年 | 2193篇 |
2006年 | 315篇 |
2005年 | 631篇 |
2004年 | 754篇 |
2003年 | 872篇 |
2002年 | 544篇 |
2001年 | 358篇 |
2000年 | 384篇 |
1999年 | 251篇 |
1998年 | 277篇 |
1997年 | 274篇 |
1996年 | 250篇 |
1995年 | 245篇 |
1994年 | 239篇 |
1993年 | 286篇 |
1992年 | 260篇 |
1991年 | 239篇 |
1990年 | 227篇 |
1989年 | 186篇 |
1988年 | 184篇 |
1987年 | 175篇 |
1986年 | 203篇 |
1985年 | 251篇 |
1984年 | 317篇 |
1983年 | 261篇 |
1982年 | 255篇 |
1981年 | 269篇 |
1980年 | 238篇 |
1979年 | 251篇 |
1978年 | 205篇 |
1977年 | 189篇 |
1976年 | 174篇 |
1975年 | 138篇 |
1974年 | 139篇 |
1973年 | 126篇 |
1972年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 656 毫秒
191.
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
192.
This article matches establishment-level data on workplace transformation (e.g., quality circles, work teams, and just-in-time production) with measures of cumulative trauma disorders at these same establishments to explore the relationship between "flexible" workplace practices and workplace health and safety. The results reveal a positive, statistically significant, and quantitatively sizable relationship between cumulative trauma disorders and the use of quality circles and just-in-time production. 相似文献
193.
194.
195.
D. P. Kennedy 《Mathematical Finance》1993,3(1):55-63
For a compound Poisson process with negative drift and jump distribution consisting of a mixture of exponentials on [0) and on (-, 0), an exact expression is derived for the probability of hitting the level c, c > 0. the problem is motivated by modeling the returns from trading on financial markets. 相似文献
196.
D. Thorsteinsson A. Semadeni-Davies R. Larsson 《Journal of Financial Services Research》1993,7(3):269-273
Shadow Financial Regulatory Committee statements 相似文献
197.
198.
199.
Andrey D. Ukhov 《The Journal of Financial Research》2004,27(3):329-339
The classical warrant pricing formula requires knowledge of the firm value and of the firm‐value process variance. When warrants are outstanding, the firm value itself is a function of the warrant price. Firm value and firm‐value variance are then unobservable variables. I develop an algorithm for pricing warrants using stock prices, an observable variable, and stock return variance. The method also enables estimation of firm‐value variance. A proof of existence of the solution is provided. 相似文献
200.
Given self-protection from an undesirable environmental externality, we examine, under several conditions, the efficiency properties of cooperative and noncooperative behavior. We demonstrate that if self-protection can transfer the externality to another agent, then noncooperative behavior will lead to overprotection. If self-protection filters or dilutes the externality, then noncooperation leads to underprotection. In addition, overprotection will worsen if an agent with more relative power is allowed a first-mover advantage or if the damage function is elastic and transferability is uncertain. Finally, a reduction in uncertainty about transferability will accentuate overprotection if the damage function is inelastic. Our results suggest that coordination of protection activities among agents will enhance the overall gains from environmental policy in the European Single Internal Market of 1992. Coordination minimizes the costs of environmental protection, thereby reducing the public credibility of its foes. 相似文献