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   2910篇
  免费   80篇
电工技术   32篇
化学工业   420篇
金属工艺   54篇
机械仪表   47篇
建筑科学   136篇
矿业工程   44篇
能源动力   60篇
轻工业   254篇
水利工程   21篇
石油天然气   31篇
武器工业   2篇
无线电   308篇
一般工业技术   352篇
冶金工业   620篇
原子能技术   14篇
自动化技术   595篇
  2023年   13篇
  2022年   15篇
  2021年   32篇
  2020年   27篇
  2019年   36篇
  2018年   44篇
  2017年   52篇
  2016年   62篇
  2015年   59篇
  2014年   82篇
  2013年   165篇
  2012年   104篇
  2011年   171篇
  2010年   135篇
  2009年   142篇
  2008年   141篇
  2007年   145篇
  2006年   145篇
  2005年   128篇
  2004年   122篇
  2003年   101篇
  2002年   84篇
  2001年   74篇
  2000年   46篇
  1999年   55篇
  1998年   59篇
  1997年   64篇
  1996年   96篇
  1995年   51篇
  1994年   44篇
  1993年   44篇
  1992年   43篇
  1991年   16篇
  1990年   35篇
  1989年   18篇
  1988年   18篇
  1987年   25篇
  1986年   24篇
  1985年   33篇
  1984年   33篇
  1983年   26篇
  1982年   20篇
  1981年   18篇
  1980年   15篇
  1979年   17篇
  1978年   15篇
  1977年   14篇
  1976年   25篇
  1975年   11篇
  1973年   11篇
排序方式: 共有2990条查询结果,搜索用时 15 毫秒
1.
2.
Terry.lee 《程序员》2004,(4):21-22
本部分将讲述PortletConfig对象及其PortletContext对象的概念及应用。  相似文献   
3.
This paper discusses the future requirements of integrated construction management systems and the need to support the management of large volumes of information on several levels. The solution proposes a combination of an efficient user interface and methods to partially automate the creation of the required information through access to stored information from past projects. The research follows the path being established for integrated construction management systems that rely on a standard representation of the industry's information requirements. By exploring the comprehensive aspects of construction planning for an integrated construction management system, the research demonstrates the usefulness of applying sound information representation structures. Through the application of case-based reasoning, the research advances the concepts of planning tools as they apply to integrated systems. The resulting prototype construction management system has the primary characteristic of assisting the user in the manipulation of information in order to generate the initial information requirements of an integrated construction management system.  相似文献   
4.
消费电子和通信产业正见证着I/O解决方案从并行到高速串行的转变:能够降低成本、简化设计,并具备可延展性,满足全新带宽的要求。这类接口I/O技术的市场潜力巨大,包括移动电话、DVD-RW和高清晰度LCD电视机,而低功耗、低电磁干扰(EMI)和高数据吞吐量在这些应用中极为重要。因此,业界一直致力于设计和开发这些串行I/O,以低功耗提供高速的数据速  相似文献   
5.
Several N-(phosphonomethyl) amides have previously been reported to act as particularly effective flame retardants for cellulose. It has also been demonstrated previously that the efficiency of a flame retardant on cellulose frequently parallels its ability to phosphorylate cellulosic hydroxyls at elevated temperatures. This study of the hydrolysis and alcoholysis reactions of N-(phosphonomethyl) amides establishes their unique reactivity. An explanation for this high reactivity is proposed on the basis of intramolecular assistance of the attack of water or alcohols at phosphorus by the carbonyl oxygen of the amide moiety.  相似文献   
6.
7.
Effects of constant voltage stress (CVS) on gate stacks consisting of an ALD HfO2 dielectric with various interfacial layers were studied with time dependent sensing measurements: DC IV, pulse IV, and charge pumping (CP) at different frequencies. The process of injected electron trapping/de-trapping on pre-existing defects in the bulk of the high-κ film was found to constitute the major contribution to the time dependence of the threshold voltage (Vt) shift during stress. The trap generation observed with the low frequency CP measurements is suggested to occur within the interfacial oxide layer or the interfacial layer/high-κ interface, with only a minor effect on Vt.  相似文献   
8.
9.
We have devised a new scheme for coding designers' cognitive actions from video/audio design protocols. Designers' actions are coded into four cognitive levels; physical, perceptual, functional and conceptual. Relations between actions belonging to different levels, such as dependencies and triggering relations, are also coded. The present scheme has two benefits. First, we found that design actions are definable in a systematic way using the vocabulary of the scheme, and thus a designer's cognitive behaviours in each of local design stages is represented as a structure composed of defined primitive actions. This is expected to lay the foundation for microscopic analyses of how particular types of actions contribute to the formation of key design ideas. Second, this scheme is suitable for macroscopic analyses of how designers cognitively interact with their own sketches. We examined, for a practising architect, the ways in which drawing, inspection of drawings, perception, and functional thoughts correlated with one another in his design process. The findings suggest that design sketches serve not only as external memory or as a provider of visual cues for association of non-visual information, but also as a physical setting in which design thoughts are constructed on the fly.  相似文献   
10.
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