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   1123篇
  免费   22篇
  国内免费   2篇
电工技术   54篇
综合类   1篇
化学工业   202篇
金属工艺   18篇
机械仪表   21篇
建筑科学   11篇
能源动力   79篇
轻工业   108篇
水利工程   2篇
无线电   139篇
一般工业技术   143篇
冶金工业   279篇
原子能技术   23篇
自动化技术   67篇
  2023年   4篇
  2022年   7篇
  2021年   16篇
  2020年   14篇
  2019年   10篇
  2018年   16篇
  2017年   14篇
  2016年   14篇
  2015年   15篇
  2014年   26篇
  2013年   49篇
  2012年   16篇
  2011年   51篇
  2010年   37篇
  2009年   36篇
  2008年   38篇
  2007年   31篇
  2006年   26篇
  2005年   27篇
  2004年   31篇
  2003年   28篇
  2002年   34篇
  2001年   34篇
  2000年   30篇
  1999年   43篇
  1998年   91篇
  1997年   64篇
  1996年   58篇
  1995年   31篇
  1994年   35篇
  1993年   25篇
  1992年   23篇
  1991年   16篇
  1990年   15篇
  1989年   13篇
  1988年   9篇
  1987年   11篇
  1986年   13篇
  1985年   12篇
  1984年   11篇
  1983年   15篇
  1982年   13篇
  1981年   3篇
  1979年   7篇
  1978年   3篇
  1977年   9篇
  1976年   13篇
  1975年   3篇
  1973年   3篇
  1965年   2篇
排序方式: 共有1147条查询结果,搜索用时 15 毫秒
91.
In this paper, we consider the successive overrelaxation method with projection for obtaining the finite element solutions under the nonlinear radiation boundary conditions. In particular we establish the convergence of the successive overrelaxation method with projection. Some numerical results are also given to illustrate the usefulness.  相似文献   
92.
The aim of this paper is to investigate the influence of multi-valency of americium in its oxide for the lowering of the thermal conductivity and the uncertainty in measurement. In the present study, thermal conductivity of non-stoichiometric americium oxide was evaluated up to 2000 K by the non-equilibrium molecular dynamics calculations using the Born-Mayer-Huggins interatomic potential with the partially ionic model. The oxygen-to-americium ratio (O/Am) was varied from 1.6 to 1.9, which corresponded to the variation of the ratio of Am3+/Am4+. So, we prepared potential parameters for both Am3+ and Am4+. The calculated thermal conductivity of non-stoichiometric americium oxide decreased with an increase of temperature, and the degree of the temperature dependence became smaller with a decrease of the O/Am ratio. This was mainly caused by the phonon-scattering due to oxygen vacancies induced with Am3+ ions. Comparing two supercells in which (1) short-range ordered Am3+ clusters were contained and (2) Am3+ ions were randomly distributed, the thermal conductivity of the former seemed to be somewhat larger than that of the latter.  相似文献   
93.
An optimum design method is presented for a "spaceless" unit structure in submarine optical fiber cable. The unit structure has been designed taking into consideration the loss increase caused by both a 40-km-long winding unit and a temperature change of 100°C. An appropriate jacket thickness and hardness was found which satisfies these requirements.  相似文献   
94.
95.
96.
Liquid crystal displays (LCDs) - born in late 1960s - have become a 45 billion-dollar industry in 2004. Today's LCD panels cover a wide range of sizes from 0.2 to 82 in diagonal. The electro-optical characteristics of any field effect LCD are determined by the orientation of its liquid crystal (LC) molecules at the display boundaries. Until recently most LCD alignment processes were based on rubbing polymer coated LCD substrates with a cloth. Despite its key importance, the complex mechanism governing the alignment of LC molecules on display substrates is still not well understood. Do the microgrooves generated by rubbing induce LC-alignment or does the stretching of polymer chains as a result of brushing cause it? To overcome the drawbacks of conventional aligning techniques, new alignment processes have recently been proposed and developed. Examples are micro embossing, ion bombardment, fringe field effects and photo-alignment. In this paper, some mechanisms of LC alignment are discussed and various alignment techniques and methods to investigate the interaction of LC molecules with substrates are reviewed.  相似文献   
97.
This paper gives an overview of the introduction and subsequent development of optical fiber cable and its application to subscriber networks enabling economical broad-band services, such as video and high-speed digital data transmissions. This paper also outlines NTT's developments on subscriber optical fiber cable technology-in particular, the five-fiber ribbon cable structure, mass-fusion splicing machine, and multifiber connector-in its ongoing endeavors to establish economical and flexible subscriber optical fiber networks which provide optical fibers to each subscriber.  相似文献   
98.
99.
K. Ishihara 《Computing》1986,37(2):137-149
In this paper we consider explicit monotone iterations of the finite element solutions for the radiation cooling problem with the nonlinear boundary conditions. These iterations provide upper and lower bounds, and convergence proofs are given. Finally, we give some numerical examples to demonstrate the effectiveness.  相似文献   
100.
Numbering 65, Nikken Sekkei's research group is the size of many substantial practices. Tomohiko Yamanashi, Tatsuya Hatori, Yoshito Ishihara and Norihisa Kawashima at Nikken Sekkei Ltd and Katsumi Niwa at the Nikken Sekkei Research Institute (NSRI) describe the unique collaborative processes that make the NSRI's contribution essential to any Nikken projects requiring the development of cutting-edge technology or urban planning proposals. Here, they detail the development of BIO SKIN, an innovative facade system developed for the Sony Research and Development Center in Tokyo, which addresses the urban heat island effect, one of the main environmental research areas of the NSRI. Copyright © 2011 John Wiley & Sons, Ltd.  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