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   2244篇
  免费   253篇
  国内免费   9篇
财政金融   246篇
工业经济   168篇
计划管理   632篇
经济学   265篇
综合类   123篇
运输经济   44篇
旅游经济   100篇
贸易经济   734篇
农业经济   98篇
经济概况   96篇
  2024年   5篇
  2023年   32篇
  2022年   30篇
  2021年   61篇
  2020年   103篇
  2019年   88篇
  2018年   109篇
  2017年   112篇
  2016年   92篇
  2015年   109篇
  2014年   196篇
  2013年   282篇
  2012年   161篇
  2011年   213篇
  2010年   172篇
  2009年   119篇
  2008年   131篇
  2007年   115篇
  2006年   88篇
  2005年   56篇
  2004年   50篇
  2003年   33篇
  2002年   25篇
  2001年   24篇
  2000年   16篇
  1999年   21篇
  1998年   17篇
  1997年   9篇
  1996年   9篇
  1995年   9篇
  1994年   8篇
  1993年   4篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1986年   1篇
  1985年   1篇
排序方式: 共有2506条查询结果,搜索用时 15 毫秒
21.
工频干扰是仪器仪表信号中的重要干扰因素,要消除它,人们通常采用滤波方法,而采用自适应滤波的方法,可以取得较好的效果。  相似文献   
22.
Bauwens  Luc  Giot  Pierre 《Empirical Economics》2003,28(4):709-731
This paper proposes an asymmetric autoregressive conditional duration (ACD) model, which extends the ACD model of Engle and Russell (1998). The asymmetry consists of letting the duration process depend on the state of the price process. If the price has increased, the parameters of the ACD model can differ from what they are if the price has decreased. The model is applied to the bid-ask quotes of two stocks traded on the NYSE and the evidence in favour of asymmetry is strong. Information effects (Easley and O'Hara 1992) are also empirically relevant. As the model is a transition model for the price process, it delivers `market forecasts' of where prices are heading. A trading strategy based on the model is implemented using tick-by-tick data.While remaining responsible for any error in this paper, the authors would like to thank R. Anderson, G. Le Fol, C. Gouriéroux, J. Jasiak, W. Pohlmeier, A. Roell, O. Scaillet, S. Wei and three anonymous referees for useful remarks and suggestions on previous versions. The authors would also like to thank A. Ruttiens from KBC-CBC for useful discussions on practical issues related to trading. Support of the European Commission Human Capital and Mobility Program through the network `Econometric inference using simulation methods' is gratefully acknowledged. This paper presents research results of the Belgian Program on Interuniversity Poles of Attraction initiated by the Belgian State, Prime Minister's Office, Science Policy Programming. The scientific responsibility is assumed by the authors.  相似文献   
23.
Germany has committed itself toreducing its carbon emissions by 25 percent in2005 as compared to 1990 emission levels. Toachieve this goal, the government has recentlylaunched an environmental tax reform whichentails a continuous increase in energy taxesin conjunction with a revenue-neutral cut innon-wage labor costs. This policy is supposedto yield a double dividend, reducing both, theproblem of global warming and high unemploymentrates. In addition to domestic actions,international treaties on climate protectionallow for the supplementary use of flexibleinstruments to exploit cheaper emissionreduction possibilities elsewhere. One concreteoption for Germany would be to enter jointimplementation (JI) with developing countriessuch as India where Germany pays emissionreduction abroad rather than meeting itsreduction target solely by domestic action. Inthis paper, we investigate whether anenvironmental tax reform cum JI providesemployment and overall efficiency gains ascompared to an environmental tax reformstand-alone. We address this question in theframework of a large-scale general equilibriummodel for Germany and India where Germany mayundertake JI with the Indian electricitysector. Our main finding is that JI offsetslargely the adverse effects of carbon emissionconstraints on the German economy. JIsignificantly lowers the level of carbon taxesand thus reduces the total costs of abatementas well as negative effects on labor demand. Inaddition, JI triggers direct investment demandfor energy efficient power plants produced inGermany. This provides positive employmenteffects and additional income for Germany. ForIndia, joint implementation equips itselectricity industry with scarce capital goodsleading to a more efficient power productionwith lower electricity prices for the economyand substantial welfare gains.  相似文献   
24.
Mixed logit models represent a powerful discrete choice analytical model but require assumptions about the functional form of the parameter distributions. The use of unbounded distributions, such as the normal distribution, may be regarded as unsuitable where theory indicates that all are negatively affected by increases in an attribute, such as price. Bounded distributions such as the triangular and log-normal are unable to model the case where a section of the population is indifferent towards an attribute, while the remainder are negatively disposed toward it. Train and Sonnier’s bounded mixed logit model accommodates these features and is employed in this paper. A censored normal and Johnson’s Sb distribution are used to model preferences in the UK for food attributes, including price and GM technology. Bi-modal distributions are identified regarding GM food: some are unlikely to ever consume it, some are close to indifference and willing to consume at relatively small discounts while the remainder are fairly unresponsive to further price reductions.  相似文献   
25.
将投入产出方法与解释结构建模相结合,取长补短,提出了基于这两种方法相结合的产业关联层次识别的分析方法,并呈现了该方法的算法步骤、识别层次结果的基本特性以及其与以往产业关联分析方法的比较优势.最后以经统一调整的1997及2002年投入产出表为基础,对我国国民经济产业关联的层次识别进行实证分析,经对识别结果的跨期对比分析,证明该识别方法的解释效果良好.  相似文献   
26.
本文利用深市基金指数高频数据,采用Anderson和Bollerslev(1997)提出的弹性傅立叶回归(FlexibleFourierFormregression,即FFF回归)方法首次对深市基金市场进行了日内周期性的研究。通过对高频收益的定性分析,发现基金市场具有同股票市场相似的周期性,并对这一周期性进行了初步的理论解释。通过FFF方法,将该周期因子进行滤波处理以后,基金指数高频绝对收益不再具有明显周期性。FFF回归能较好地确定日内周期因子。  相似文献   
27.
物流系统建模方法的研究   总被引:2,自引:0,他引:2  
通过对现有系统建模分析方法的比较和分析,针对物流系统提出了一种集成建模分析GI-SIM法。该方法以概念、功能和动态建模思想为基础,以GRAI格、IDEFO和仿真技术为建模工具,满足了复杂物流系统的建模要求。最后,给出了GI-SIM法的建模步骤,并对其进行了总结和评价。  相似文献   
28.
李新东  程国全 《物流技术》2006,(12):34-36,67
通过对物流系统规划与仿真模型的分析,归纳出系统规划模型与系统仿真模型的共有属性和关系,采用集成化的技术,建立集成化规划一仿真系统模型,并通过Solidworks和Flexsim研究实现其集成化,并在相关课题中获得成功应用,突破了现有软件在规划与仿真之间数据共享的壁垒。  相似文献   
29.
董翔英  王学群  王凤忠 《物流技术》2007,26(10):124-126
基于信息流分析,论述了军用车辆器材调拨系统中信息流程和业务流程的重组和优化应用,采用对象、岗位、任务三维视图的建模方法描述核心业务流程,提高了系统的可读性和可推广性。  相似文献   
30.
本文从企业经营者人力资本的一般特征入手,进一步延伸分析了企业经营者人力资本的产权特征,在此基础上论述了企业经营者激励与约束的制度选择,即赋予企业经营者剩余控制权和部分剩余索取权。  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