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   30903篇
  免费   348篇
财政金融   5609篇
工业经济   1815篇
计划管理   4851篇
经济学   6933篇
综合类   606篇
运输经济   125篇
旅游经济   241篇
贸易经济   6703篇
农业经济   649篇
经济概况   3092篇
信息产业经济   47篇
邮电经济   580篇
  2023年   84篇
  2021年   98篇
  2020年   217篇
  2019年   284篇
  2018年   2602篇
  2017年   2371篇
  2016年   1514篇
  2015年   308篇
  2014年   434篇
  2013年   1735篇
  2012年   827篇
  2011年   2369篇
  2010年   2218篇
  2009年   1933篇
  2008年   1895篇
  2007年   2185篇
  2006年   404篇
  2005年   654篇
  2004年   727篇
  2003年   820篇
  2002年   527篇
  2001年   342篇
  2000年   338篇
  1999年   295篇
  1998年   316篇
  1997年   265篇
  1996年   234篇
  1995年   220篇
  1994年   237篇
  1993年   239篇
  1992年   262篇
  1991年   253篇
  1990年   200篇
  1989年   181篇
  1988年   165篇
  1987年   162篇
  1986年   180篇
  1985年   237篇
  1984年   253篇
  1983年   244篇
  1982年   211篇
  1981年   194篇
  1980年   168篇
  1979年   167篇
  1978年   156篇
  1977年   133篇
  1976年   123篇
  1975年   139篇
  1974年   99篇
  1973年   100篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
This paper compares the stylized facts of the European growth cycle stemming from the Gross Domestic Product (GDP) of the European Monetary Union with an unobserved common factor derived from a dynamic factor model with regime switching. The aim of this paper is to provide empirical evidence about the most adequate indicator for short-term monitoring of the cyclical state of the European economy. Previous versions of this article have been presented at the 55th International Atlantic Economic Conference (Vienna, Austria, March 12–16, 2003) and at the VI Encuentro de Economía Aplicada (Granada, Spain, June 5–7, 2003). The author would like to thank the conference participants and an anonymous referee for their comments and suggestions.  相似文献   
992.
The objective of this paper is to estimate the dynamics of aquaculture and fish prices as a response to price shocks. The vector autoregression approach will be used to explain the dynamics of the sea bream market in both cultured and wild fishing. The main result is that changes in public regulation or in production conditions could stimulate production responses which may take time to settle. Usually, the change is a matter of adjusting between equilibria over a period of time, with the pattern and speed of the adjustment, depending on the nature and degree of disequilibrium in the fishing system. Comments from reviewers have been incorporated into the paper and are gratefully acknowledged. Financial support was provided by Direcció General de Recerca, Departament d'Universitats, Recerca i Societat de la Informació project No SGR2001-160.  相似文献   
993.
This article presents a model of innovation and diffusion of machines which embody a new technology. Users of the machines are heterogenous in their skill level. Skilled machine-users adopt new machines first, while unskilled users wait until machines become more user-friendly and reliable. The improvement of machines is the engine of diffusion, and it is carried out by the monopolist machine producer. The speed of diffusion is affected by the skill distribution in the economy. At any point in time, the machine producer can innovate a new generation of machines. The timing of innovation is also influenced by the skill distribution.  相似文献   
994.
It was known that deep within numbers and binary data from simulations of geophysical convective flows resided various patterns. Two models of convective fluid flows were being considered. One was a model of two-dimensional (768 × 256) air convection with finite Prandtl number of one and Rayleigh number of 108?1010, and another was a model of three-dimensional (up to 120 × 120 × 90) mantle convection with infinite Prandtl number and Rayleigh number of 106?108. Clearly, phenomena existed which superceded each individual dimensionless computer model to provide a piece of information regarding actual fluid flows. The problem was how to find, prove, and communicate these patterns and phenomena for convection simulations with gigabytes of data. In a search for such an analytical and communicative tool, the alternative of visualization was considered. The need for visualization was recognized and discussed. Then, utilizing both two- and three-dimensional models of high Rayleigh number convection, basic techniques of style and content were developed. Applications of the visualization techniques were designed utilizing IBM’s Data Explorer in order to create communicative images and movies, and after the applications, the problems of data storage and transfer became apparent. Throughout the process though, it became clear how important the language of vision actually could be in the geophysics community. In a field in which words such as plumes and internal waves have in ways replaced mathematics as the basic language for science, there is a need for another resource, another language-the visualization of convective fluid flows.  相似文献   
995.
Among the current literatures that discuss the influence exerted on residents’ consumption behavior by capital liquidity, some often independently decide the demarcation point of the liquidity restriction that affects residents’ consumption behavior, without taking into account when the economy is flourishing whether residents will be influenced by the restriction of the liquidity that their consumption behaviors can not be fully carried out. We introduce a threshold model which varies according to the actual GDP and other financial indicators (money supply, average stock index and balance of bank loans) to discuss residents’ consumption behavior in China under different economic states. The empirical results show that when the economy flourishes or resuscitates, residents’ income of the same period have not notable influence on their consumption, which suggests that residents’ consumption behavior does not considerably change according to the fluctuation of the current income, but conforms with the constant income-life cycle hypothesis. Moreover, two estimated values 0.7504 and 0.8597, as economic boom measures, all fall in the boom stable stage—basically consists with the early-warning index of the macro-economy boom issued by National Bureau of Statistics of China. It shows that the macro-economic boom is not notablely influenced by capital liquidity, so is residents’ consumption behavior.  相似文献   
996.

We find the closed form solution for the joint probability of the running maximum and the drawdown of the Brownian motion with a non-zero drift parameter at a random time that is exponentially distributed and independent of the Brownian motion. This characterization leads us to come up with a robust method of estimating volatility using open, high, low and closing prices. We rigorously show the independence of robust volatility estimators based on extreme values of asset prices relative to the standard robust volatility estimator based on closing price alone. We further prove that the proposed robust volatility ratio is unbiased with no drift parameter. Moreover, we find that the robust volatility ratio with a non-zero drift parameter has only a second order effect. We have shown that our proposed extreme value robust volatility estimator is 2–3 times relatively more efficient when compared to the classical robust volatility estimator based on Monte Carlo simulation experiment. On the empirical side, we test the proposed robust volatility ratio based on high and low prices on different asset classes like stock indices, exchange rate and precious metals.

  相似文献   
997.
We analyze the impact of product diversification on performance. This topic has been discussed in the literature, and there is no consensus so far as to the significance or the direction of the impact. Performance is measured using Tobin's q for a sample of 103 large, non-financial Spanish firms (1992–1995). Diversification is measured by means of a categorical variable, as suggested by Varadarajan. The principal results indicate that the firms with intermediate levels of product diversification have the highest performance, while the firms with low and high levels of diversification show significantly lower performance, which performance is not significantly different between them.  相似文献   
998.
Summary. We discuss a competitive (labor) market where firms face capacity constraints and individuals differ according to their productivity. Firms offer two-dimensional contracts like wage and task level. Then workers choose firms and contracts. Workers might be rationed if the number of applicants exceeds the capacity of the firm. We show that under reasonable assumptions on the distribution of capacity an equilibrium in pure strategies (by the firms) exists. This result stands in contrast to the case of unlimited capacity. The utility level is uniquely determined in equilibrium. No rationing occurs in equilibrium, but it does off the equilibrium path. Received: December 29, 1999; revised version: November 30, 2000  相似文献   
999.
Summary. This paper defines and studies optimality in a dynamic stochastic economy with finitely lived agents, and investigates the optimality properties of an equilibrium with or without sequentially complete markets. Various Pareto optimality concepts are considered, including interim and ex ante optimality. We show that, at an equilibrium with a productive asset (land) and sequentially complete markets, the intervention of a government may be justified, but only to improve risk sharing between generations. If markets are incomplete, constrained interim optimality is investigated in two-period lived OLG economies. We extend the optimality properties of an equilibrium with land and give conditions under which introducing a pay-as-you-go system at an equilibrium would not lead to any Pareto improvement. Received: October 5, 1998; revised version: April 3, 2001  相似文献   
1000.
Summary. This paper considers a dynamic version of Akerlof's (1970) lemons problem where buyers and sellers must engage in search to find a trading partner. We show that if goods are durable, the market itself may provide a natural sorting mechanism. In equilibrium, high-quality goods sell at a higher price than low-quality goods but also circulate longer. This accords with the common wisdom that sellers who want to sell fast may have to accept a lower price. We then compare the equilibrium outcomes under private information with those under complete information. Surprisingly, we find that for a large range of parameter values the quilibrium outcomes under the two information regimes coincide, despite the fact that circulation time is used to achieve separation. Received: August 24, 2000; revised version: October 24, 2000  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