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   167946篇
  免费   1323篇
  国内免费   191篇
电工技术   2551篇
综合类   118篇
化学工业   26257篇
金属工艺   9471篇
机械仪表   5714篇
建筑科学   3002篇
矿业工程   1887篇
能源动力   2703篇
轻工业   8771篇
水利工程   2728篇
石油天然气   8692篇
武器工业   12篇
无线电   14487篇
一般工业技术   38249篇
冶金工业   27792篇
原子能技术   6932篇
自动化技术   10094篇
  2018年   2977篇
  2017年   3091篇
  2016年   3344篇
  2015年   1672篇
  2014年   2954篇
  2013年   6338篇
  2012年   4311篇
  2011年   5397篇
  2010年   4420篇
  2009年   4894篇
  2008年   4940篇
  2007年   4868篇
  2006年   4140篇
  2005年   3819篇
  2004年   3634篇
  2003年   3520篇
  2002年   3450篇
  2001年   3463篇
  2000年   3361篇
  1999年   3212篇
  1998年   7018篇
  1997年   5148篇
  1996年   3821篇
  1995年   2916篇
  1994年   2593篇
  1993年   2720篇
  1992年   2254篇
  1991年   2304篇
  1990年   2409篇
  1989年   2315篇
  1988年   2313篇
  1987年   2190篇
  1986年   2246篇
  1985年   2282篇
  1984年   2199篇
  1983年   2119篇
  1982年   1962篇
  1981年   2181篇
  1980年   2048篇
  1979年   2249篇
  1978年   2425篇
  1977年   2422篇
  1976年   3082篇
  1975年   2239篇
  1974年   2296篇
  1973年   2333篇
  1972年   2152篇
  1971年   1902篇
  1970年   1694篇
  1969年   1623篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Refractories and Industrial Ceramics - Results of studying the rheotechnological properties of moldable refractory mixes based on bauxite suspensions plasticized with refractory clay are presented....  相似文献   
62.
The influence of phase composition and microstructure of Ti42.75Zr27Mn20.25V10 alloy on its hydrogenation kinetic and phase composition of hydrogenated product was studied. It is established that the process of dissociation of hydrogen molecules begins on the surface of Laves phase crystallites. The dissolution of atomic hydrogen in the material volume leads to the formation of cracks in the intermetallic crystallites, which further appear as additional centers of dissociation of hydrogen molecules and noticeably accelerate the diffusion of hydrogen into the bulk material. It was shown that the Laves phase acts as a donor of atomic hydrogen for the BCC solid solution during hydrogenation of two-phase structure, initiating intensive hydrogenation of the BCC phase at room temperature.  相似文献   
63.
International Journal of Computer Vision - Anticipating future situations from streaming sensor data is a key perception challenge for mobile robotics and automated vehicles. We address the problem...  相似文献   
64.
Theoretical Foundations of Chemical Engineering - A choline chloride–sulfosalicylic acid deep eutectic solvent (DES) is proposed for dissolving the oxides Co(II), Cu(II), Zn(II), Fe(III),...  相似文献   
65.
Atomic Energy - The results of calculations and experimental determination of the neutronics characteristics of the IRT-T research reactor are presented. The IRT-T reactor is a pool reactor with...  相似文献   
66.
High Temperature - Experimental findings suggest that a strongly ionized, arc He plasma of atmospheric pressure does not exist in the state of the local thermodynamic equilibrium (LTE) expected for...  相似文献   
67.
Russian Engineering Research - Improvement in the wear resistance of plunger-pump rods is considered. Hardening by high-frequency current is proposed.  相似文献   
68.
Potentiometric sensors with plasticized poly(vinyl chloride) membranes based on β-lactam–tetraalkylammonium ion associates sensitive to penicillin antibiotics are proposed. The physicochemical characteristics (solubility product constants and dissociation constants) of active membrane components and the electrode, transport, and selective properties of the membranes of liquidand solid-contact sensors have been studied. The quantitative characteristics of membrane transport (penetrability, ion flux, and transport rate) have been evaluated. The main charge carriers in the membranes and at the membrane/solution interface have been determined from the membrane transport characteristics. The potentiometric sensors are shown to be applicable to the determination of penicillin antibiotics in biological fluids (blood serum and oral fluid) from patients with urinary tract infection.  相似文献   
69.
The authors have developed a procedure and a test bench for studying evolution of various nature physical fields in modeling geomedium fracture by fluids. The test bench performs synchronous recording of macro- and micro-deformation, heat and acoustic emission induced in physical models of geomedium under loading to discontinuity. The experimental procedure has been trialed. The analysis of the synchronized test data allows a conclusion on the existence of time–space relationship between different nature physical fields induced during failure of solids.  相似文献   
70.
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