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   12057篇
  免费   532篇
  国内免费   318篇
电工技术   226篇
技术理论   1篇
综合类   558篇
化学工业   2207篇
金属工艺   908篇
机械仪表   1383篇
建筑科学   518篇
矿业工程   468篇
能源动力   373篇
轻工业   519篇
水利工程   108篇
石油天然气   262篇
武器工业   53篇
无线电   776篇
一般工业技术   964篇
冶金工业   601篇
原子能技术   38篇
自动化技术   2944篇
  2024年   20篇
  2023年   84篇
  2022年   122篇
  2021年   218篇
  2020年   234篇
  2019年   206篇
  2018年   153篇
  2017年   228篇
  2016年   316篇
  2015年   356篇
  2014年   630篇
  2013年   734篇
  2012年   614篇
  2011年   913篇
  2010年   549篇
  2009年   595篇
  2008年   558篇
  2007年   754篇
  2006年   728篇
  2005年   692篇
  2004年   636篇
  2003年   594篇
  2002年   491篇
  2001年   398篇
  2000年   371篇
  1999年   311篇
  1998年   270篇
  1997年   207篇
  1996年   184篇
  1995年   155篇
  1994年   151篇
  1993年   90篇
  1992年   68篇
  1991年   59篇
  1990年   42篇
  1989年   23篇
  1988年   33篇
  1987年   16篇
  1986年   9篇
  1985年   10篇
  1984年   17篇
  1983年   7篇
  1982年   16篇
  1981年   9篇
  1979年   7篇
  1978年   9篇
  1977年   8篇
  1975年   2篇
  1974年   3篇
  1954年   1篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
陈庆军 《非织造布》2006,14(2):23-26
介绍了应用于非织造布印花的技术及工艺,对非织造布印花时应注意的事项进行了说明。  相似文献   
82.
黄思龙  梁家珊 《柳钢科技》2007,(F09):271-274
介绍柳钢35t转炉方坯连铸机系统优化措施,通过优化使生产稳定性提高,铸坯质量得到改善,提高各项经济技术指标。  相似文献   
83.
本文针对拟薄水铝石生产线中的关键环节—烘干系统的设备产能问题进行了分析和技术改造,收到了较好的效果,并为同类生产企业及今后改、扩建工作提供了有益的借鉴。  相似文献   
84.
A model-based autotuning method consists of an identification and a regulator tuning phase. To achieve satisfactory performance and robustness, it is advisable that both phases be tailored a priori to the characteristics of the observed process dynamics. Such characteristics include, but are not limited to, the model structure. For example, overdamped and underdamped models with the same pole-zero structure are parametrised and controlled in different ways. Step response data, that are typically used for the identification phase in the autotuning context, can also be pre-processed to reveal those characteristics. This paper presents a step response classification method suitable for the above purpose. The method is based on a polygonal curve approximation technique for data pre-processing, followed by a neural network classifier. Only normalised I/O data are employed, so that the neural network can be trained off-line with simulated data. Simulation results are reported to show the effectiveness of the proposed classification method in terms of the achievable tuning results.  相似文献   
85.
86.
张向东  谢洪儒 《宽厚板》1997,3(4):17-20
S—135钢板是水电站用高强耐磨不锈钢板,既要求强度高、韧性好,又要求耐磨、耐蚀性强,生产难度较大。除我厂外,目前国内尚无其它厂家能够生产这种钢板。该钢板在加热轧制,冷却过程中要解决很多技术难点。我们通过采用特殊的控制轧制和控制冷却工艺,很好地解决了诸多技术难点,使S—135钢板的开发研制取得了成功。为电站用高强度耐磨不锈钢生产提供了宝贵的经验,也为控制轧制及控制冷却技术在中板生产行业的应用起到了积极的推动作用。  相似文献   
87.
Information technology has been becoming increasingly important in all areas of engineering during the last few years. Much of the progress achieved in chemical engineering would not have been possible without the enabling methods and tools provided by information technology. This trend will continue in the future but most likely with a considerably wider scope. While individual software tools and services have been in focus until recently, their integration into engineering work processes is an emerging and challenging area of research and development. This contribution attempts to highlight state of the art and future trends in supporting the activities during the life cycle of a chemical process by means of information technology. Emphasis will be largely on the process and plant design process rather than on procurement, manufacturing, and distribution of materials in the supply chain.  相似文献   
88.
There are two popular approaches to specifying the semantics of process algebras: labelled transition semantics and reaction semantics. While the notion of free name is rather unproblematic for labelled transition semantics this is not so for reaction semantics in the presence of a structural congruence for unfolding recursive declarations.We show that the standard definition of free name is not preserved under the structural congruence. We then develop a fixed point approach to the set of free names and show that it is invariant under the structural congruence.  相似文献   
89.
90.
The multiprocess performance analysis chart (MPPAC) based on the process capability index Cpm, called Cpm MPPAC, is developed for analysing the manufacturing quality of a group of processes in a multiple process environment. The Cpm MPPAC conveys critical information of multiple processes regarding the departure of the process and process variability from one single chart. Existing research works on MPPAC are restricted to obtaining quality information from one single sample of each process ignoring sampling errors. The information provided from existing MPPAC charts, therefore, is unreliable and misleading and results in incorrect decisions. In this paper, we consider the natural estimator of Cpm based on multiple samples. Based on the natural estimator of Cpm, we consider the sampling errors by providing an explicit formula with the Matlab program to obtain the estimation accuracy of the Cpm. We tabulate the sampling accuracy of Cpm for sample size determination so that the engineers/practitioners can use it for their in-plant applications. An example of multiple precision voltage reference (PVR) processes is presented to illustrate the applicability of Cpm MPPAC for manufacturing quality control.  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