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   11441篇
  免费   450篇
  国内免费   156篇
财政金融   392篇
工业经济   971篇
计划管理   3695篇
经济学   1960篇
综合类   1128篇
运输经济   60篇
旅游经济   199篇
贸易经济   1571篇
农业经济   655篇
经济概况   1416篇
  2024年   66篇
  2023年   201篇
  2022年   315篇
  2021年   415篇
  2020年   394篇
  2019年   218篇
  2018年   205篇
  2017年   241篇
  2016年   292篇
  2015年   432篇
  2014年   1055篇
  2013年   1155篇
  2012年   1009篇
  2011年   1159篇
  2010年   961篇
  2009年   604篇
  2008年   596篇
  2007年   552篇
  2006年   478篇
  2005年   423篇
  2004年   317篇
  2003年   231篇
  2002年   184篇
  2001年   158篇
  2000年   117篇
  1999年   73篇
  1998年   52篇
  1997年   34篇
  1996年   17篇
  1995年   20篇
  1994年   19篇
  1993年   9篇
  1992年   5篇
  1991年   4篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   4篇
  1984年   6篇
  1983年   12篇
  1982年   10篇
  1981年   1篇
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
41.
讨论了全低变工艺开发过程中遇到的一些问题和对策,对中、小氮肥企业进行技术改造具有一定的参考意义。  相似文献   
42.
我国武器装备通用ATS(自动测试系统)经历了从引进、仿制到自行研制的过程,但是目前通用ATS总的局面是通用ATS不通用,这种局面主要是由于国内对通用ATS实现技术缺乏统一认识造成的。基于此,本文研究了与开发通用ATS密切相关的标准/规范、硬件配置技术、接口技术、集成测试软件开发环境技术。本文的研究结果适用于所有开发通用ATS的项目。  相似文献   
43.
朱春红  张亮  赵宏 《特区经济》2006,(12):229-230
国内外科技园区的发展实践证明,科技中介服务体系的建立与完善是研发与转化基地建设必不可少的重要基础和支撑。本文结合滨海新区的实际,对滨海新区研发与转化基地建设中的科技中介服务体系的目标定位、结构设计以及高效运行的保障措施进行了重点探讨。  相似文献   
44.
发达国家科技政策导向及其启示   总被引:3,自引:0,他引:3  
当今世界,科技政策已成为许多国家尤其是美、日、欧等发达国家全力打造科技强国的基本的公共政策。文章从国家战略引导产业发展、国家政策促进产业发展、全力追求知识与技术创新、注重培养和吸纳优秀人才等4个方面对此进行了探析。  相似文献   
45.
We examine the two traditions of content analysis: the first in which one substitutes words of a text with categories, and the second in which one looks for clusters of words that may refer to a theme. In the first tradition, preexisting dictionary categories give meaning to the words; in the second, meaning comes after the fact. Preexisting dictionary categories (the substitution model) are calibrated instruments applied within experimental designs that leave no space for doubt; meanwhile, the ability of the correlational model to conjure up complex themes from fragments of a text yields no unique solution. These differences have bearings on the production of new social knowledge. We expound on the epistemological foundations of the two traditions of interpretation and draw from them decision rules upon which one may rely for choosing among appropriate content-analytic tactics. Two reasons make this essay timely and critical: (1) the increasing variety of new content-analyticsoftware for particular purposes and (2) the almost exclusive focusing on software and technology at the expense of adjusting the choice of the software to the nature of the text. Two studies, one in historiometry, the other in autobiography, illustrate the liabilities and benefits of the two models of content analysis.  相似文献   
46.
文章从科技人力资源、科技资金资源、科技物质资源和科技信息资源等方面分析了常德市科技资源配置的现状、存在的问题,并提出了相应的对策和建议。  相似文献   
47.
Probability theory in fuzzy sample spaces   总被引:2,自引:0,他引:2  
This paper tries to develop a neat and comprehensive probability theory for sample spaces where the events are fuzzy subsets of The investigations are focussed on the discussion how to equip those sample spaces with suitable -algebras and metrics. In the end we can point out a unified concept of random elements in the sample spaces under consideration which is linked with compatible metrics to express random errors. The result is supported by presenting a strong law of large numbers, a central limit theorem and a Glivenko-Cantelli theorem for these kinds of random elements, formulated simultaneously w.r.t. the selected metrics. As a by-product the line of reasoning, which is followed within the paper, enables us to generalize as well as to bring together already known results and concepts from literature.Acknowledgement. The author would like to thank the participants of the 23rd Linz Seminar on Fuzzy Set Theory for the intensive discussion of the paper. Especially he is indebted to Professors Diamond and Höhle whose remarks have helped to get deeper insights into the subject. Additionally, the author is grateful to one anonymous referee for careful reading and valuable proposals which have led to an improvement of the first draft.This paper was presented at the 23rd Linz Seminar on Fuzzy Set Theory, Linz, Austria, February 5–9, 2002.  相似文献   
48.
宋广辉 《物流科技》2004,27(6):25-27
介绍无菌纸包装设备的原理,讨论影响无菌包装的有关因素,介绍无菌包装主要特性。  相似文献   
49.
浅析网络信息安全技术   总被引:4,自引:0,他引:4  
文章总结分析了网络信息的几种安全技术,并简要叙述了安全技术的具体应用。  相似文献   
50.
This research examines whether investments in advanced manufacturing technologies (AMTs) such as flexible manufacturing systems (FMS), computer aided design (CAD), computer aided manufacturing (CAM), robotics, etc., are more likely to lead to improved performance if they are supported by improvements in the manufacturing infrastructure of the company. This question is evaluated using data gathered from 202 manufacturing plants chosen from industries generally considered to have relatively high investments in technology.Multiple item scales are developed and adapted from sources in the literature to measure investments in technology, infrastructure, and the performance of the plant. Evidence supporting the reliability and validity of these scales is provided. Hierarchical regression is used to analyze the relationship between technology, infrastructure, and performance. The results suggest that there is an important interaction between the adoption of advanced manufacturing technologies and investments in infrastructure. Firms that invest in both AMTs and infrastructure perform better than firms which only invest in one or the other. Separate analyses on sub-samples of firms with the highest and lowest investments in AMTs show that infrastructural investments have a stronger relationship with performance in the high investment group. Thus, the data indicate that infrastructural investments provide a key to unlocking the potential of advanced manufacturing technologies.  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