全文获取类型
收费全文 | 13861篇 |
免费 | 373篇 |
专业分类
财政金融 | 2524篇 |
工业经济 | 1057篇 |
计划管理 | 2383篇 |
经济学 | 3264篇 |
综合类 | 175篇 |
运输经济 | 121篇 |
旅游经济 | 240篇 |
贸易经济 | 2054篇 |
农业经济 | 602篇 |
经济概况 | 1755篇 |
信息产业经济 | 2篇 |
邮电经济 | 57篇 |
出版年
2021年 | 70篇 |
2020年 | 150篇 |
2019年 | 236篇 |
2018年 | 254篇 |
2017年 | 317篇 |
2016年 | 284篇 |
2015年 | 181篇 |
2014年 | 317篇 |
2013年 | 1376篇 |
2012年 | 385篇 |
2011年 | 434篇 |
2010年 | 347篇 |
2009年 | 459篇 |
2008年 | 400篇 |
2007年 | 343篇 |
2006年 | 317篇 |
2005年 | 302篇 |
2004年 | 294篇 |
2003年 | 330篇 |
2002年 | 284篇 |
2001年 | 285篇 |
2000年 | 309篇 |
1999年 | 290篇 |
1998年 | 273篇 |
1997年 | 281篇 |
1996年 | 248篇 |
1995年 | 234篇 |
1994年 | 216篇 |
1993年 | 224篇 |
1992年 | 233篇 |
1991年 | 234篇 |
1990年 | 241篇 |
1989年 | 200篇 |
1988年 | 186篇 |
1987年 | 185篇 |
1986年 | 201篇 |
1985年 | 256篇 |
1984年 | 227篇 |
1983年 | 214篇 |
1982年 | 216篇 |
1981年 | 208篇 |
1980年 | 195篇 |
1979年 | 211篇 |
1978年 | 171篇 |
1977年 | 157篇 |
1976年 | 145篇 |
1975年 | 104篇 |
1974年 | 112篇 |
1973年 | 113篇 |
1972年 | 77篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
101.
Statistical inference based on the Weibull distribution, a distribution widely used in reliability and survival analysis,
is usually difficult as it often involves numerical computation and approximation. However, this distribution can be transformed
to near-normality by a simple power transformation. Based on this transformation, a prediction interval (PI) for its median
can be easily constructed through an inverse transformation. The procedure for selecting the best power transformation through
minimizing Kullback-Leibler information is described. The property of this transformation-based PI is investigated. Simple
correction factors are also proposed. It is shown that the transformation-based PI with corrections performs well, irrespective
of the sample size and parameter values. Simulation results show that the new PI generally outperforms the existing PI. Numerical
examples are given for illustration. 相似文献
102.
Abstract
Technology analysis is a new technomanagerial discipline that provides common frameworks for analysing individual technologies and their relationships to each other. It is used here to probe the development of a particular technology, namely that of permanent magnets.
The paper traces the development of permanent magnets over the past decade and explores possible future improvements in performance parameters. The strength of magnets (i.e. energy product as expressed in kilo Joules per cubic metre) has increased from approximately 40 in the 1930s to approximately 400 at present.
Future developments will be constrained by a barrier which seems to exist at approximately 525 kilo Joules per cubic metre. However this is viewed as a barrier that can be transcended and not as an immutable limit. It therefore signifies a possible breakthrough zone.
S-curve theory leads analysts to speculate about a possible breakthrough during the five year period leading up to 1995. At that date magnetic strengths of 600+ kilo Joules per cubic metre could be aimed for.
Increased magnetic strength will improve the performance parameters of all technologies utilising magnets, unleash new magnetic based technologies and threaten many traditional areas in the fields of matter processing, transporting and storing, energy processing, and information processing and storing.
These effects will cascade through the entire technological landscape creating new markets and destroying others. The article gives an overview of these impacts on the technological landscape. 相似文献
Technology analysis is a new technomanagerial discipline that provides common frameworks for analysing individual technologies and their relationships to each other. It is used here to probe the development of a particular technology, namely that of permanent magnets.
The paper traces the development of permanent magnets over the past decade and explores possible future improvements in performance parameters. The strength of magnets (i.e. energy product as expressed in kilo Joules per cubic metre) has increased from approximately 40 in the 1930s to approximately 400 at present.
Future developments will be constrained by a barrier which seems to exist at approximately 525 kilo Joules per cubic metre. However this is viewed as a barrier that can be transcended and not as an immutable limit. It therefore signifies a possible breakthrough zone.
S-curve theory leads analysts to speculate about a possible breakthrough during the five year period leading up to 1995. At that date magnetic strengths of 600+ kilo Joules per cubic metre could be aimed for.
Increased magnetic strength will improve the performance parameters of all technologies utilising magnets, unleash new magnetic based technologies and threaten many traditional areas in the fields of matter processing, transporting and storing, energy processing, and information processing and storing.
These effects will cascade through the entire technological landscape creating new markets and destroying others. The article gives an overview of these impacts on the technological landscape. 相似文献
103.
The conceptual model presented in this article argues that corporations exhibit specific behaviors that signal their true level of moral development. Accordingly, the authors identify five levels of moral development and discuss the dynamics that move corporations from one level to another. Examples of corporate behavior which are indicative of specific stages of moral development are offered.R. Eric Reidenbach is Professor of Marketing and Director of the Center for Business Development and Research at the University of Southern Mississippi. He has written extensively on business and marketing ethics.Donald P. Robin, Professor of Business Ethics and Professor of Marketing at the University of Southern Mississippi, is coauthor with R. Eric Reidenbach of two recent books on business ethics with Prentice-Hall. He is a frequent lecturer on business ethics and is the author of several articles on the subject. 相似文献
104.
An Erratum for this article has been published in Journal of Applied Econometrics 18(2) 2003, 249 Previous empirical work on corporate growth rates using cross‐section or short‐panel econometric techniques suggests that growth rates are random but that some degree of mean reversion exists. This means that size differences between firms are transitory. Another, more natural way to explore the long‐run distribution of firm sizes is to examine data on the growth of particular firms over long periods of time. Using a sample of 147 UK firms observed continually for more than 30 years, our conclusions are that growth rates are highly variable over time and that differences in growth rates between firms do not persist for very long. Further, firms show no tendency to converge to either a common size or to a pattern of stable size differences over time. These results are compared and contrasted with standard approaches that suggest that firms reach and maintain stable positions in a skewed size distribution. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
105.
106.
Financial flows between center and region are analyzed on the example of the Republic of Buryatia. Significant changes are shown to have occurred in the interbudgetary relations between the federal center and the region, which are associated with a revised delineation of authorities between different levels of authority. It has been the key factor in changing the sources and volumes of financial flows. The analysis is largely focused on the relations between the region and its municipalities. 相似文献
107.
Richard P. O’Neill Emily Bartholomew Fisher Benjamin F. Hobbs Ross Baldick 《Journal of Regulatory Economics》2008,34(3):220-250
The general design for the real-time electricity market presented in this paper optimizes and prices both real and reactive
power simultaneously in an AC setting, where all assets—generation, load and transmission—are allowed to bid and are financially
settled at the locational price times energy consumed or produced. The result is that transmission lines are compensated for
both capacity and admittance, providing incentives for efficient operation of transmission-related assets such as FACTS devices,
if price-taking behavior is assumed. Losses are incorporated into the design and become an operating cost for transmission.
The market design is shown to be revenue neutral and, under some assumptions, nonconfiscatory.
相似文献
108.
109.
Articles featured in the symposium:
Author's reply to Wheeler–Getman–Brody papers by Lance Compa, School of Industrial and Labor Relations
The Wagner Act Model: A Toxic System beyond Repair by Roy J. Adams De Groote, School of Business, McMaster University, Hamilton, Ontario
Choosing an Interpretation of the Right to Freedom of Association by Sheldon Leader, Department of Law and the Centre for Human Rights, University of Essex 相似文献
Author's reply to Wheeler–Getman–Brody papers by Lance Compa, School of Industrial and Labor Relations
The Wagner Act Model: A Toxic System beyond Repair by Roy J. Adams De Groote, School of Business, McMaster University, Hamilton, Ontario
Choosing an Interpretation of the Right to Freedom of Association by Sheldon Leader, Department of Law and the Centre for Human Rights, University of Essex 相似文献
110.
KENNETH J. KLASSEN JEFFREY A. PITTMAN MARGARET P. REED STEVE FORTIN 《Contemporary Accounting Research》2004,21(3):639-680
We provide evidence on the impact of tax incentives and financial constraints on corporate R&D expenditure decisions. We contribute to extant research by comparing R&D expenditures in the United States and Canada, thereby exploiting the differences in the two countries' R&D tax credit mechanisms and generally accepted accounting principles. The two tax incentive mechanism designs are consistent with differing views of the degree of financial constraints faced by firms in these economies. Our sample also allows us to explore the effects of capitalizing R&D on Canadian firms. Employing a matched design, we document relations between tax credit incentives and R&D spending consistent with both Canadian and U.S. public companies responding as though they are not financially constrained. We estimate that the Canadian credit system induces, on average, $1.30 of additional R&D spending per dollar of taxes forgone while the U.S. system induces, on average, $2.96 of additional spending. We also find that firms that capitalize R&D costs in Canada spend, on average, 18 percent more on R&D. Collectively, this evidence is important to the ongoing debates in both countries concerning the appropriate design of incentives for R&D and is consistent with the assumptions found in the U.S. tax credit system, but not those found in the Canadian system. 相似文献