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   11423篇
  免费   300篇
财政金融   1992篇
工业经济   838篇
计划管理   1962篇
经济学   2803篇
综合类   141篇
运输经济   83篇
旅游经济   133篇
贸易经济   1672篇
农业经济   533篇
经济概况   1510篇
邮电经济   56篇
  2021年   75篇
  2020年   120篇
  2019年   198篇
  2018年   219篇
  2017年   273篇
  2016年   252篇
  2015年   149篇
  2014年   269篇
  2013年   1085篇
  2012年   327篇
  2011年   341篇
  2010年   279篇
  2009年   393篇
  2008年   294篇
  2007年   260篇
  2006年   238篇
  2005年   245篇
  2004年   212篇
  2003年   256篇
  2002年   203篇
  2001年   218篇
  2000年   233篇
  1999年   229篇
  1998年   203篇
  1997年   217篇
  1996年   195篇
  1995年   169篇
  1994年   173篇
  1993年   194篇
  1992年   202篇
  1991年   194篇
  1990年   196篇
  1989年   170篇
  1988年   162篇
  1987年   160篇
  1986年   173篇
  1985年   204篇
  1984年   192篇
  1983年   181篇
  1982年   168篇
  1981年   184篇
  1980年   166篇
  1979年   185篇
  1978年   149篇
  1977年   141篇
  1976年   126篇
  1975年   92篇
  1974年   99篇
  1973年   100篇
  1972年   77篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
On April 1, 1988, New Zealand stopped the double taxation of dividends by implementing a full dividend imputation program. Because many believed that the tax advantage of debt had led to more highly leveraged firms subject to greater financial risk than was socially optimal, it was hoped the removal of incentives to finance with debt would result in a more efficient allocation of capital. The empirical results suggest that the shareholder wealth gain from dividend imputation was more than offset in firms with large debt levels. Moreover, an examination of debt ratios indicates debt levels declined in the post–imputation period.  相似文献   
92.
Random urinalysis strategies stratified by time since the last test are characterized with a set of Markov chain models. The probability of a person being tested depends on the amount of time since the person's last test. The Nuclear Regulatory Commission (NRC) has proposed a two strata drug testing strategy based on time since last test. The proposal included a high testing rate for people not yet tested in a given time period and a low testing rate for people testing negative in a given time period. Southern California Edison has implemented a variation of the NRC proposal. These strategies can be modeled within a Markov chain framework. Time to detection is calculated as a function of testing probabilities and drug usage levels. Drug user gaming strategies are discussed with illustrations. These models are implemented as part of a U.S. Navy drug policy analysis system.  相似文献   
93.
94.
95.
Modeling Conditional Yield Densities   总被引:2,自引:0,他引:2  
Given the increasing interest in agricultural risk, many have sought improved methods to characterize conditional crop-yield densities. While most have postulated the Beta as a flexible alternative to the Normal, others have chosen nonparametric methods. Unfortunately, yield data tends not to be sufficiently abundant to invalidate many reasonable parametric models. This is problematic because conclusions from economic analyses, which require estimated conditional yield densities, tend not to be invariant to the modeling assumption. We propose a semiparametric estimator that, because of its theoretical properties and our simulation results, enables one to empirically proceed with a higher degree of confidence.  相似文献   
96.
The behaviour of stock prices on the Colombo Stock Exchange (CSE) is examined with a view to determine its consistency with the weak form of the Efficient Markets Hypothesis (EMH). Runs, Autocorrelation and Cointegration tests are applied to daily, weekly and monthly CSE index data for the period of January 1991–November 1996. Results of Runs, Correlation and Cointegration tests overwhelmingly reject the serial independence hypothesis, leading to the conclusion that the behaviour of stock prices in the Colombo Stock Exchange is not consistent with the weak form of the Efficient Markets Hypothesis. Tests of the-day-of-the-week-effect, however, show that there is no evidence of such a phenomenon on the Colombo Stock Exchange stock prices. Results of the tests of the-month-of-the-year-effect lead to the conclusion that CSE prices do not display any month-specific behaviour.  相似文献   
97.
98.
本文介绍一组(12个)新的正弦振荡器,这组振荡器使用两个运算放大器,其振荡频率不受单极点有源元件增益带宽之积的影响。这种特性是由本文所介绍的电路结构取得的,即不需要调节。  相似文献   
99.
Estimation in the interval censoring model is considered. A class of smooth functionals is introduced, of which the mean is an example. The asymptotic information lower bound for such functionals can be represented as an inner product of two functions. In case 1, i.e. one observation time per unobservable event time, both functions can be given explicitly. We mainly consider case 2, with two observation times for each unobservable event time, in the situation that the observation times can not become arbitrarily close to each other. For case 2, one of the functions in the inner product can only be given implicitly as solution to a Fredholm integral equation. We study properties of this solution and, in a sequel to this paper, prove that the nonparametric maximum likelihood estimator of the functional asymptotically reaches the information lower bound.  相似文献   
100.
Between 1974 and 1988, executives of DuPont, the world's largest producer of CFCs, were confronted with emerging evidence that CFCs were destroying the stratospheric ozone layer. The difficulty that executives face in such cases is that scientific knowledge develops over time and does not necessarily proceed in a straight line toward true conclusions. At the beginning of a new field of research, there is much uncertainty and disagreement among the experts. The solution of the ozone problem required a remarkable cooperation among science, business, and international governments. After looking at the role of DuPont executives in this drama, and the difficulties facing any executive dealing with uncertain science, the paper turns to an evaluation of the field of Business Ethics to see what light it might throw on this and analogous problems. Finally, the paper offers specific suggestions in terms of principles in dealing with uncertain science, and concludes that the course of action that DuPont followed, including some mistakes, can serve as a model for analogous crises.  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