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   2826篇
  免费   108篇
  国内免费   4篇
财政金融   441篇
工业经济   229篇
计划管理   1004篇
经济学   372篇
综合类   148篇
运输经济   78篇
旅游经济   22篇
贸易经济   271篇
农业经济   136篇
经济概况   235篇
信息产业经济   2篇
  2025年   32篇
  2024年   47篇
  2023年   64篇
  2022年   72篇
  2021年   89篇
  2020年   127篇
  2019年   88篇
  2018年   61篇
  2017年   84篇
  2016年   102篇
  2015年   126篇
  2014年   220篇
  2013年   311篇
  2012年   210篇
  2011年   258篇
  2010年   147篇
  2009年   117篇
  2008年   168篇
  2007年   138篇
  2006年   111篇
  2005年   67篇
  2004年   54篇
  2003年   62篇
  2002年   32篇
  2001年   35篇
  2000年   20篇
  1999年   17篇
  1998年   17篇
  1997年   19篇
  1996年   14篇
  1995年   9篇
  1994年   4篇
  1993年   5篇
  1992年   2篇
  1991年   5篇
  1990年   2篇
  1985年   1篇
  1984年   1篇
排序方式: 共有2938条查询结果,搜索用时 15 毫秒
171.
This article argues that lessons on how to achieve a sustainable financial system can be learnt from the work done on sustainable commons (on common‐pool resources – CPRs – where there is no ‘tragedy of the commons’). Existing approaches to financial regulation may not give proper attention to available solutions. The article proposes that innovative solutions could be tested using experimental methods commonly used in CPRs: repeat run, feedback driven games.  相似文献   
172.
    
Most work in strategy and organization theory assumes that performance feedback is straightforward to interpret and truthfully reported. We raise the following question: How might the systematic distortion of negative performance information affect organizational learning and future performance? We formulate a model where (1) members do not always report the truth about what they know about their performance level, especially when performance is below aspiration and (2) their propensity to distort information is subject to social influence. We find that organizations that are characterized by a high level of information distortion tend to perform more poorly but that the effect of a low rate of sugarcoating may, in some conditions, be more benign than the literatures seem to suggest. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
173.
The paper takes up inference in the stochastic frontier model with gamma distributed inefficiency terms, without restricting the gamma distribution to known integer values of its shape parameter (the Erlang form). The paper shows that Gibbs sampling with data augmentation can be used in a computationally efficient way to explore the posterior distribution of the model and conduct inference regarding parameters as well as functions of interest related to technical inefficiency.  相似文献   
174.
李守朝 《价值工程》2011,30(33):1-3
林樊家油田林东馆三段地质条件复杂,地层敏感性强,供液差,产能低,油稠,出砂严重,多年来采用了各种工艺措施,均未取得好的水驱开采效果。文章运用数值模拟手段,分析了低水驱的主要原因和论证了低效水驱转蒸汽热采可行性。在此基础上,研究了该块低效水驱转蒸汽热采的开发经济技术政策界限。开发实践表明,低效水驱稠油油藏通过转热采可大幅提高采收率,同时研究成果对同类油藏的开发具有重要指导意义。  相似文献   
175.
    
The classical stochastic frontier panel data models provide no mechanism to disentangle individual time invariant unobserved heterogeneity from inefficiency. Greene (2005a, b) proposed the so-called “true” fixed-effects specification that distinguishes these two latent components. However, due to the incidental parameters problem, his maximum likelihood estimator may lead to biased variance estimates. We propose two alternative estimators that achieve consistency for n with fixed T. Furthermore, we extend the Chen et al. (2014) results providing a feasible estimator when the inefficiency is heteroskedastic and follows a first-order autoregressive process. We investigate the behavior of the proposed estimators through Monte Carlo simulations showing good finite sample properties, especially in small samples. An application to hospitals’ technical efficiency illustrates the usefulness of the new approach.  相似文献   
176.
为探讨基于HLA的建模仿真技术在器材保障物流仿真领域中的应用,作者在分析器材保障物流系统运行框架的基础上,结合FEDEP模型,构建了基于HLA的器材保障物流系统仿真模型,接着研究了仿真模型中的联邦功能模型,开发了仿真联邦成员,建立了联邦体系结构模型,并对联邦运行模型中的初始化、仿真运行、仿真结束三个阶段分别进行了分析,实现高效、精确模拟器材保障物流系统的运行过程。  相似文献   
177.
Although conceptually pleasing, normal-gamma frontier models lead to difficult estimation problems. It is shown here that unless the sample size reaches several thousands of observations the shape parameter of the gamma density is hard to estimate, and that this carries over to estimates of the stochastic frontier, the individual inefficiencies, and the allocation of the overall variance to the stochastic frontier and to the inefficiencies.  相似文献   
178.
文章从多分辨率交通仿真的建模过程入手,研究了系统仿真的校核、验证与确认(Verification Validation Accreditation,VVA)过程评价的原理。在此基础上,提出了基于VVA的多分辨率交通仿真建模的过程评价框架。通过研究仿真系统生命周期中的一系列活动来评价研究结果的正确性和有效性,提高了系统的可信性,使仿真系统能够满足实际应用的需要。  相似文献   
179.
This paper empirically examines whether three East Asian stock markets, namely, those of China, Japan and South Korea, are individually and/or jointly efficient, and whether contagion exists between the cointegrated markets. While individual market efficiency is examined through testing for the random walk hypothesis, joint market efficiency is examined through testing for cointegration and contagion. The present study finds that the hypothesis of individual market efficiency is strongly rejected for the Chinese stock market, but not for the Japanese and the South Korean stock markets. However, when testing for cointegration, market efficiency is strongly rejected for all these markets. We take a simple case of contagion and find that although there is a long‐term relationship among the three markets, the contagion hypothesis cannot be rejected only between Japanese and South Korean stock markets, indicating short‐run portfolio diversification benefits from these two markets.  相似文献   
180.
简要介绍了无刷直流电机的工作原理,建立了BLDCM数学模型及simulink仿真模型.仿真结果表明波形符合理论分析,系统具有良好的静、动态特性.  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