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   9120篇
  免费   1080篇
  国内免费   25篇
财政金融   1358篇
工业经济   648篇
计划管理   1896篇
经济学   1888篇
综合类   499篇
运输经济   160篇
旅游经济   127篇
贸易经济   1903篇
农业经济   520篇
经济概况   1217篇
邮电经济   9篇
  2024年   14篇
  2023年   50篇
  2022年   83篇
  2021年   201篇
  2020年   300篇
  2019年   596篇
  2018年   324篇
  2017年   504篇
  2016年   457篇
  2015年   512篇
  2014年   571篇
  2013年   881篇
  2012年   715篇
  2011年   796篇
  2010年   736篇
  2009年   475篇
  2008年   560篇
  2007年   519篇
  2006年   517篇
  2005年   416篇
  2004年   198篇
  2003年   181篇
  2002年   173篇
  2001年   161篇
  2000年   110篇
  1999年   44篇
  1998年   18篇
  1997年   17篇
  1996年   16篇
  1995年   19篇
  1994年   11篇
  1993年   8篇
  1992年   3篇
  1991年   3篇
  1990年   4篇
  1989年   1篇
  1988年   5篇
  1987年   8篇
  1986年   1篇
  1985年   3篇
  1984年   7篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
  1974年   1篇
  1971年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
环保型水性上光油的研制与应用   总被引:1,自引:0,他引:1  
金振华 《化工科技市场》2003,26(3):26-27,23
目前,涂布上光技术已被越来越多的印刷厂家所采用,促使上光油的需求量不断上升。经过近几年的努力,我院研制的环保型水性上光油已取得了突破性的进展,完全能够替代溶剂型水性上光油和油性上光油,由于水性上光油具有无毒、无味、透明感强、无有机挥发物(VOC)的排放,成本低、原材料来源广等特点,在使用中能赋予印刷良好的光泽性、耐折性、耐磨性和化学品性,尤其是它所具有的环保性能特别适合食品、药品和烟草等行业包装印刷材料的加工。  相似文献   
12.
The margin system is the first line of defense against the default risk of a clearinghouse. From the perspectives of a clearinghouse, the utmost concern is to have a prudential system to control the default exposure. Once the level of prudentiality is set, the next concern will be the opportunity cost of the investors, because high opportunity cost discourages people from hedging futures, and thus defeats the function of a futures market. In this article, we first develop different measures of prudentiality and opportunity cost. We then formulate a statistical framework to evaluate different margin‐setting methodologies, all of which strike a balance between prudentiality and opportunity cost. Three margin‐setting methodologies, namely, (1) using simple moving averages; (2) using exponentially weighted moving averages; (3) using a GARCH approach, are applied to the Hang Seng Index futures. Keeping the same prudentiality level, it is shown that the one using a GARCH approach by and large gives the lowest average overcharge. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:117–145, 2004  相似文献   
13.
This article uses a nonparametric test based on the arc‐sine law (see, e.g., Feller, 1965 ), which involves comparing the theoretical distribution implied by an intraday random walk with the empirical frequency distribution of the daily high/low times, in order to address the question of whether the abandonment of pit trading has been associated with greater market efficiency. If market inefficiencies result from flaws in the market microstructure of pit trading, they ought to have been eliminated by the introduction of screen trading. If, on the other hand, the inefficiencies are a reflection of investor psychology, they are likely to have survived, unaffected by the changeover. We focus here on four cases. Both the FTSE‐100 and CAC‐40 index futures contracts were originally traded by open outcry and have moved over to electronic trading in recent years, so that we are able to compare pricing behavior before and after the changeover. The equivalent contracts in Germany and Korea, on the other hand, have been traded electronically ever since their inception. Our results overwhelmingly reject the random‐walk hypothesis both for open‐outcry and electronic‐trading data sets, suggesting there has been no increase in efficiency as a result of the introduction of screen trading. One possible explanation consistent with our results would be that the index futures market is characterized by intraday overreaction. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:337–357, 2004  相似文献   
14.
This article analyzes the effects of the length of hedging horizon on the optimal hedge ratio and hedging effectiveness using 9 different hedging horizons and 25 different commodities. We discuss the concept of short‐ and long‐run hedge ratios and propose a technique to simultaneously estimate them. The empirical results indicate that the short‐run hedge ratios are significantly less than 1 and increase with the length of hedging horizon. We also find that hedging effectiveness increases with the length of hedging horizon. However, the long‐run hedge ratio is found to be close to the naïve hedge ratio of unity. This implies that, if the hedging horizon is long, then the naïve hedge ratio is close to the optimum hedge ratio. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:359–386, 2004  相似文献   
15.
The notion that prices impound a wide array of information, including market expectations, has led to earnings forecast models conditioned on prices. Yet, presumably, analysts' forecasts capture both public information and certain private information not previously impounded in prices. Accordingly, price-based models are seemingly an inefficient, and less effective, source of expecta-tions. This article investigates this hypothesis using financial analysts', price-based, and naive forecasts. Results indicate that analysts' forecasts (1) are at least as accurate as price-based and naive models, and (2) yield better expectations for market tests relating returns and earnings. These inferences are robust across different information environments. The evidence suggests that analysts either possess private information or are more effective information processors, or both.  相似文献   
16.
Structural vector autoregressive (SVAR) models have emerged as a dominant research strategy in empirical macroeconomics, but suffer from the large number of parameters employed and the resulting estimation uncertainty associated with their impulse responses. In this paper, we propose general‐to‐specific (Gets) model selection procedures to overcome these limitations. It is shown that single‐equation procedures are generally efficient for the reduction of recursive SVAR models. The small‐sample properties of the proposed reduction procedure (as implemented using PcGets) are evaluated in a realistic Monte Carlo experiment. The impulse responses generated by the selected SVAR are found to be more precise and accurate than those of the unrestricted VAR. The proposed reduction strategy is then applied to the US monetary system considered by Christiano, Eichenbaum and Evans (Review of Economics and Statistics, Vol. 78, pp. 16–34, 1996) . The results are consistent with the Monte Carlo and question the validity of the impulse responses generated by the full system.  相似文献   
17.
Announcements of syndication loans increase borrowers' shareholder wealth if they are revolving credit agreements but not if they are term loans. Share price responses to revolving credit announcements are positive and significant, whereas the wealth effect for term loans is negative and significant. The results show that announcements from both the financial press and commercial information providers can affect borrower share price reaction. Overall, single syndication announcements appear to be more newsworthy than multiple announcements reported in the financial press, and we find evidence of information leakage, post‐announcement drift, or both.  相似文献   
18.
Portfolio value‐at‐risk (PVAR) is widely used in practice, but recent criticisms have focused on risks arising from biased PVAR estimates due to model specification errors and other problems. The PVAR estimation method proposed in this article combines generalized Pareto distribution tails with the empirical density function to model the marginal distributions for each asset in the portfolio, and a copula model is used to form a joint distribution from the fitted marginals. The copula–mixed distribution (CMX) approach converges in probability to the true marginal return distribution but is based on weaker assumptions that may be appropriate for the returns data found in practice. CMX is used to estimate the joint distribution of log returns for the Taiwan Stock Exchange (TSE) index and the associated futures contracts on SGX and TAIFEX. The PVAR estimates for various hedge portfolios are computed from the fitted CMX model, and backtesting diagnostics indicate that CMX outperforms the alternative PVAR estimators. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:997–1018, 2006  相似文献   
19.
In 1996, the Korean mobile communication market was the first in the world to commercialize the code division multiple access (CDMA). Since then, the voice-based mobile phone market has continued to grow and has now reached near saturation. Having recognized the potential of the mobile data service as a new source of profit, telecommunication operators are scrambling to evolve 3.5 generation (3.5G) technology in order to lead market competition. Recently, the Korean 3.5G mobile telecom market has faced stiff competition from CDMA-based EVDO Rev.A and global system for mobile telecommunications (GSM)-based high-speed downlink packet access (HSDPA). In addition, the world's first wireless LAN-based wireless broadband internet (WiBro) service was commercialized in June, 2006. This paper reviews the current status of the 3.5G technology and analyzes the service standardization strategies from the viewpoint of technological evolutions. This paper also suggests implications for Korea's specific circumstances where different mobile telecom technologies complement and compete with one another. Korea's experiences may serve as important lessons for other countries or operators who try to introduce the 3G and look beyond mobile telecom technologies.  相似文献   
20.
This paper examines the causal relationship between financial development and economic growth for six Middle Eastern and North African countries (Algeria, Egypt, Israel, Morocco, Syria, and Tunisia), within a quadvariate vector autoregressive framework. We employ four different measures of financial development and apply the augmented vector autoregression vector (VAR) methodology of Toda and Yamamoto to test for Granger causality. Our empirical results strongly support the hypothesis that finance leads to growth in five out of the six countries. Only in Israel could weak support be found for causality running from economic growth to financial development but no causality in the other direction. These findings suggest the need to accelerate the financial reforms that have been launched since the mid 1980s and to improve the efficiency of these countries’ financial systems to stimulate saving/investment and, consequently, long‐term economic growth.  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