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   22110篇
  免费   1039篇
  国内免费   69篇
电工技术   264篇
综合类   40篇
化学工业   4823篇
金属工艺   407篇
机械仪表   434篇
建筑科学   1176篇
矿业工程   83篇
能源动力   570篇
轻工业   1420篇
水利工程   228篇
石油天然气   79篇
武器工业   1篇
无线电   1636篇
一般工业技术   4615篇
冶金工业   3535篇
原子能技术   135篇
自动化技术   3772篇
  2023年   222篇
  2022年   511篇
  2021年   642篇
  2020年   447篇
  2019年   426篇
  2018年   562篇
  2017年   467篇
  2016年   665篇
  2015年   546篇
  2014年   831篇
  2013年   1380篇
  2012年   1201篇
  2011年   1509篇
  2010年   1107篇
  2009年   1040篇
  2008年   1173篇
  2007年   1158篇
  2006年   926篇
  2005年   831篇
  2004年   724篇
  2003年   592篇
  2002年   661篇
  2001年   408篇
  2000年   386篇
  1999年   353篇
  1998年   438篇
  1997年   370篇
  1996年   286篇
  1995年   313篇
  1994年   261篇
  1993年   284篇
  1992年   215篇
  1991年   128篇
  1990年   188篇
  1989年   159篇
  1988年   154篇
  1987年   154篇
  1986年   118篇
  1985年   180篇
  1984年   165篇
  1983年   113篇
  1982年   94篇
  1981年   91篇
  1980年   68篇
  1979年   72篇
  1978年   70篇
  1977年   51篇
  1976年   95篇
  1975年   49篇
  1974年   41篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
The Six Sigma approach is one of the more recent initiatives adopted by organisations who seek to make a paradigm shift in performance improvement (attacking at least one of the cost, quality, delivery measurements for improved competitiveness). Is there anything new about Six Sigma, does it offer improvements that other approaches cannot, or is it just a clever delivery of repackaged goods? The author investigates the above questions related to the Six Sigma approach  相似文献   
2.
During large scale wildfires, suppression activities are carried out under the direction of an Incident Management Team (IMT). The aim of the research was to increase understanding of decision processes potentially related to IMT effectiveness. An IMT comprises four major functions: Command, Operations, Planning, and Logistics. Four methodologies were used to study IMT processes: computer simulation experiments; analyses of wildfire reports; interviews with IMT members; and cognitive ethnographic studies of IMTs. Three processes were important determinants of IMT effectiveness: information management and cognitive overload; matching component function goals to overall goals; and team metacognition to detect and counter task‐disruptive developments. These processes appear to be complex multi‐person analogues of individual Incident Command processes identified previously. The findings have implications for issues such as: creating IMTs; training IMTs; managing IMTs; and providing decision support to IMTs.  相似文献   
3.
随着SoC设计元件的出现,如MIPS32 1004K一致处理系统(CPS),单操作系统条件下的片上对称多处理(SMP)已经成为了一种真正的设计选择,而系统架构师也需要了解其优点和局限性。  相似文献   
4.
5.
Recent years have witnessed major governmental initiatives regarding critical infrastructure protection (CIP). During that same time, critical infrastructures (CIs) have undergone massive institutional restructuring under the headings of privatization, deregulation and liberalization. Little research has gone into understanding the interactions between these two developments. In this article, we outline the consequences of institutional restructuring for the changing ways in which CIs ensure the reliability and security of their networks and services. Neither Normal Accident Theory nor High‐Reliability Theory can account for reliability under these conditions. We then investigate the implications of these findings for CIP.  相似文献   
6.
Choosing a standard speed for visual inspection is difficult using standard work measurement techniques. This paper uses a different approach, taking a model of human functioning in inspection and deriving an optimum speed of working so as to balance the cost of time against the cost of errors. Random search is used as the model and both self-paced and externally-paced conditions are derived for multiple fault types. Optimization using a Golden Section search is used to provide optimum inspection speed.  相似文献   
7.
8.
The interaction of ammonium stearate (AS) and γ-aminopropyltriethoxysilane (APS) treatments with a magnesium hydroxide flame retardant filler and their effects on its use in an ethylene vinyl acetate copolymer compound have been investigated. The work has shown clear evidence of changes in the structure of the surface layers formed on the filler as the amount of additive is increased and the levels at which these occur can be correlated with theoretical monolayer quantities. Infrared (IR) spectroscopy data suggest that the stearate coating changes from a half salt to a full salt as the coating level is increased and that the APS coating on the filler initially has a significant bicarbonate content, presumably due to reaction with atmospheric carbon dioxide. The effect of coating level on the melt flow rate, insoluble matrix content, crystallisation behaviour, tensile properties, limiting oxygen index, and ageing of the filled compound has been studied. Distinct trends have been observed, many of which can be correlated with the structure of the filler surface layers. Of particular importance is the observation that, unlike APS, excess stearate appears to promote detrimental ageing effects.  相似文献   
9.
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