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   44559篇
  免费   793篇
  国内免费   161篇
财政金融   5352篇
工业经济   2844篇
计划管理   7588篇
经济学   7117篇
综合类   2476篇
运输经济   223篇
旅游经济   280篇
贸易经济   4597篇
农业经济   2051篇
经济概况   5360篇
水利工程   7527篇
信息产业经济   6篇
邮电经济   92篇
  2023年   334篇
  2022年   567篇
  2021年   855篇
  2020年   839篇
  2019年   648篇
  2018年   645篇
  2017年   1026篇
  2016年   793篇
  2015年   863篇
  2014年   1203篇
  2013年   2520篇
  2012年   2758篇
  2011年   4294篇
  2010年   3705篇
  2009年   2628篇
  2008年   2737篇
  2007年   2726篇
  2006年   2842篇
  2005年   2444篇
  2004年   1015篇
  2003年   851篇
  2002年   749篇
  2001年   778篇
  2000年   606篇
  1999年   612篇
  1998年   438篇
  1997年   399篇
  1996年   377篇
  1995年   321篇
  1994年   316篇
  1993年   268篇
  1992年   288篇
  1991年   267篇
  1990年   201篇
  1989年   185篇
  1988年   160篇
  1987年   148篇
  1986年   144篇
  1985年   204篇
  1984年   191篇
  1983年   196篇
  1982年   154篇
  1981年   187篇
  1980年   164篇
  1979年   186篇
  1978年   167篇
  1977年   142篇
  1976年   153篇
  1975年   127篇
  1974年   128篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
31.
The secondary effluent from municipal plants in Korea generally represents higher BOD with lower SS. Therefore, more soluble forms of organics and NH4-N need to be removed to improve its effluent for reuse. In this study reuse possibility of secondary effluent and CSO (combined sewer overflow) using BAF (biological aerated filter) was evaluated. The tertiary application with 1.2 h EBCT, SS, BOD and COD showed stable concentrations less than 1.3, 1.3 and 6.2 mg/L, respectively. Nitrogen could be nitrified even at 7 degrees suggesting BAF can be used for a water reuse method as well as an effective add-on facility in cold regions. However, BAF was not stable with CSO application at increased flow rates suggesting CSO must be equalised prior to application. Disinfection was necessary even during normal weather conditions.  相似文献   
32.
关于邮政短信平台建设的探讨   总被引:1,自引:0,他引:1  
汪青 《邮政研究》2005,21(2):14-16
为了有效地促进传统邮政业务的发展,开拓新的邮政业务领域,创造新的业务增长点,文章对发展邮政短信业务的相关问题作了分析,并结合安徽省的具体建设条件,对邮政短信平台建设的必要性、原则以及系统方案作了具体阐述。  相似文献   
33.
The purpose of this study was to assess the basis behavior of the Live Cattle Futures contract at the Chicago Mercantile Exchange (CME) before and after the 1995 contract changes. Additionally, an alternative method of basis calculation utilizing weighted mean futures prices versus settlement futures prices was compared to determine which method provides a better representation of the basis level. Within a regression model with heteroskedascity error framework, we found that the level of nearby basis in the period after June 1995 has shifted lower and the average monthly open interest of net commercial long positions has substantially increased after the contract modifications. These empirical results are consistent with the notion that more long activity entered the market in response to the contract modifications. Additionally, an alternative (new) measure of basis calculation (cash price minus weighted mean futures price) produced similar results to two other commonly used measures. In conclusion, the 1995 contract changes have neither increased nor decreased the volatility of live cattle basis. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:557–590, 2004  相似文献   
34.
We apply a discrete choice approach to model the empirical behaviour of the Federal Reserve in changing the federal funds target rate, the benchmark of short‐term market interest rates in the US. Our methods allow the explanatory variables to be nonstationary as well as stationary. This feature is particularly useful in the present application as many economic fundamentals that are monitored by the Fed and are believed to affect decisions to adjust interest rate targets display some nonstationarity over time. The chosen model successfully predicts the majority of the target rate changes during the time period considered (1994–2001) and helps to explain strings of similar intervention decisions by the Fed. Based on the model‐implied optimal interest rate, our findings suggest that there is a lag in the Fed's reaction to economic shocks during this period. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
35.
The idea of judo economics, building on analogies with the sport of judo, has been around for at least 20 years. But taking these ideas further to judo strategy means that a framework of strategic principles can be developed to help companies put stronger opponents on the mat.  相似文献   
36.
37.
38.
Book review     
CLIMATIC FLUCTUATIONS AND WATER MANAGEMENT. by M. A. Abu‐Zeid and A. K. Biswas Butterworth Heinemann, Oxford, 1992, 356 pp, £50.00.  相似文献   
39.
This paper examines the comments submitted by UK companies on 20 proposed accounting standards to test the hypotheses that executives favor standards that increase, or dampen the variance of, accounting profit numbers on which their incentive remuneration is based. Test results were generally as hypothesised but only the profit variance outcomes were statistically significant. Allowing for political environment changes affected only the profit variance results. There was no evidence that the relative monetary size of bonus payments was a significant lobbying factor. No significant differences were found between the lobbying preferences of companies with or without executive incentive schemes.  相似文献   
40.
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