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   4037篇
  免费   231篇
  国内免费   47篇
财政金融   268篇
工业经济   469篇
计划管理   1804篇
经济学   359篇
综合类   290篇
运输经济   26篇
旅游经济   48篇
贸易经济   590篇
农业经济   148篇
经济概况   313篇
  2024年   13篇
  2023年   53篇
  2022年   62篇
  2021年   90篇
  2020年   93篇
  2019年   59篇
  2018年   58篇
  2017年   85篇
  2016年   82篇
  2015年   167篇
  2014年   387篇
  2013年   357篇
  2012年   386篇
  2011年   510篇
  2010年   405篇
  2009年   226篇
  2008年   283篇
  2007年   235篇
  2006年   198篇
  2005年   155篇
  2004年   105篇
  2003年   72篇
  2002年   43篇
  2001年   53篇
  2000年   24篇
  1999年   27篇
  1998年   23篇
  1997年   23篇
  1996年   8篇
  1995年   5篇
  1994年   2篇
  1993年   6篇
  1992年   3篇
  1991年   3篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1985年   3篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
排序方式: 共有4315条查询结果,搜索用时 15 毫秒
1.
孙英潮 《科技和产业》2021,21(2):238-242
基于严寒区京沈客专朝阳试验段路基基床的温度监测资料分析,研究不同厚度聚氨酯保温板对高速铁路路基混凝土基床温度变化特性影响.测试结果表明:①铺设聚氨酯保温板能够有效阻断严寒区环境与路基基床间的热量传递,保温效果与板厚相关;②地温大多数时间呈阳高阴低现象,同时阴、阳坡路基温差波动幅度随埋深逐渐减小;③基床表层阴、阳面各测点的温度变化起始时间一致,而阴面的冻结时间比阳面晚一个月.由此表明,保温板能够有效降低环境与混凝土道床之间的热交换,但是对路基阴、阳坡的影响存在差异.建议在严寒地区高速铁路路基阳、阴坡可以采取不同厚度的聚氨酯保温板,减小阴阳坡地温差异,保持季冻土路基温度变化稳定.  相似文献   
2.
如何在课堂上培养职业判断能力   总被引:2,自引:0,他引:2  
会计教学的目的不仅在于训练学生毕业时即已成为一个专业人员,而且是在培养他们未来成为一个专业人员应有的素质。会计教学改革的首要任务,是如何着力提高会计专业学生职业判断能力的培养。会计职业要求不仅要具备良好的理论基础,还必须能够在实践中运用这些知识。会计职业判断就是在符合国家法律法规的前提下,如何在可持续的基础上为所有者价值最大化进行企业会计政策的选择与设计。  相似文献   
3.
教育测量是指对教育现象的测量。教育测量的基本手段是存在失真范围的数量化分析。其数量化的语言是效度、信度等。效度分为效标效度与内容效度等,信度是表明测量可靠性的数量指标。  相似文献   
4.
通信信号的识别与解调是通信侦察的重要研究内容,在通常情况下,通信信号的很多参数并不知道。本文介绍了一种基于通信信号码延迟自相关特性的码速率测量技术,并给出了码速率测量理论分析及基于硬件的实现技术,仿真和实验结果表明本方案具有较高的测量性能。  相似文献   
5.
介绍了计轴自动站间闭塞和调度集中设备概况,针对这些技术设备在青藏铁路哈尔盖—格尔木间的应用,论述了相应的行车组织对策,并根据目前的有关规章要求,对计轴自动站间闭塞方式和调度集中作业提出了应进一步研究和探讨的问题。  相似文献   
6.
由酚醛玻璃纤维增强塑料热压成型生产的耐腐蚀水环式真空泵是一种新型的耐腐蚀真空设备,它比普通水环式真空泵耐腐蚀效果理想,并且不易造成泵轴扭断,维修量小,节电效果显著,是一种值得广泛推广的真空设备。  相似文献   
7.
Strategic management research has been characterized as placing less emphasis on construct measurement than other management subfields. In this work, we document the state of the art of measurement in strategic management research, and discuss the implications for interpreting the results of research in this field. To assess the breadth of measurement issues in the discipline, we conducted a content analysis of empirical strategic management articles published in leading journals in the period of 1998–2000. We found that few studies discuss reliability and validity issues, and empirical research in the field commonly relies on single‐indicator measures. Additionally, studies rarely address the problems of attenuation due to measurement error. We close with a discussion of the implications for future research and for interpreting prior work in strategic management. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
8.
This paper demonstrates that applications of existing approaches to measuring market orientation are myopic, non-comparative and over-reliant on the views of single respondents. Consequently, a multi-perspective, multi-informant approach for measuring market orientation is generated which focuses on gauging customers', competitors' and intra-organizational members' perceptions of the market orientation of an organization. To evaluate the psychometric properties of this approach an application of this design in a survey of manufacturing industry is subjected to tests for inter-rater reliability, scale reliability, content validity, criterion-related validity and construct validity. The conclusion of this evaluation is that the developed measure is both a reliable and valid means of gauging market orientation. The paper concludes with a series of implications for both theorists and practitioners.  相似文献   
9.
This paper contrasts goal-directed and institutional approaches to the development of performance measurement (PM) in the Swedish university sector, which has been subject to increasing emphasis on management by objectives since the early 1990s. We adopt a macro perspective, focusing on recent changes in PM related to governmental control of universities and colleges and combine an extensive review of archival data with interviews in our empirical analysis. It is concluded that although the goal-directed model cannot be completely rejected as a heuristic informing recent changes in PM, a process-orientated institutional perspective considerably enriches the analysis by making it less static and more contextually informed. In particular, the latter perspective better explains the evolution of loose couplings between formally stated goals and performance indicators and between different systems for PM by directing attention to the complex interplay between conflicting constituent interests in the evolution of resource and cost allocation practices and quality control procedures. However, our empirical analysis also leads us to reconsider the conceptions of loose coupling as either a “given” feature of institutionalised organizations or an outcome of more pro-active resistance at the micro level prevailing in much earlier work in institutional theory.  相似文献   
10.
A bilinear multivariate errors-in-variables model is considered. It corresponds to an overdetermined set of linear equations AXB=C, A∈ℝm×n, B∈ℝp×q, in which the data A, B, C are perturbed by errors. The total least squares estimator is inconsistent in this case.  An adjusted least squares estimator is constructed, which converges to the true value X, as m →∞, q →∞. A small sample modification of the estimator is presented, which is more stable for small m and q and is asymptotically equivalent to the adjusted least squares estimator. The theoretical results are confirmed by a simulation study. Acknowledgements. We thank two anonymous reviewers for their suggestions and corrections.? A. Kukush is supported by a postdoctoral research fellowship of the Belgian office for Scientific, Technical and Cultural Affairs, promoting Scientific and Technical Collaboration with Central and Eastern Europe.? S. Van Huffel is a full professor with the Katholieke Universiteit Leuven.? I. Markovsky is a research assistant with the Katholieke Universiteit Leuven.? This paper presents research results of the Belgian Programme on Interuniversity Poles of Attraction (IUAP V-22), initiated by the Belgian State, Prime Minister's Office – Federal Office for Scientific, Technical and Cultural Affairs of the Concerted Research Action (GOA) projects of the Flemish Government MEFISTO-666 (Mathematical Engineering for Information and Communication Systems Technology), of the IDO/99/03 project (K.U. Leuven) “Predictive computer models for medical classification problems using patient data and expert knowledge”, of the FWO projects G.0078.01, G.0200.00, and G0.0270.02.? The scientific responsibility is assumed by its authors.  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