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   170786篇
  免费   1490篇
  国内免费   199篇
电工技术   2615篇
综合类   121篇
化学工业   27001篇
金属工艺   9543篇
机械仪表   5765篇
建筑科学   3060篇
矿业工程   1890篇
能源动力   2784篇
轻工业   9128篇
水利工程   2745篇
石油天然气   8704篇
武器工业   12篇
无线电   14741篇
一般工业技术   38682篇
冶金工业   28253篇
原子能技术   6964篇
自动化技术   10467篇
  2018年   3057篇
  2017年   3168篇
  2016年   3415篇
  2015年   1726篇
  2014年   3062篇
  2013年   6525篇
  2012年   4415篇
  2011年   5560篇
  2010年   4526篇
  2009年   5050篇
  2008年   5072篇
  2007年   4966篇
  2006年   4232篇
  2005年   3897篇
  2004年   3711篇
  2003年   3573篇
  2002年   3507篇
  2001年   3515篇
  2000年   3413篇
  1999年   3270篇
  1998年   7151篇
  1997年   5256篇
  1996年   3893篇
  1995年   2964篇
  1994年   2635篇
  1993年   2757篇
  1992年   2277篇
  1991年   2317篇
  1990年   2433篇
  1989年   2330篇
  1988年   2330篇
  1987年   2204篇
  1986年   2262篇
  1985年   2308篇
  1984年   2217篇
  1983年   2146篇
  1982年   1995篇
  1981年   2211篇
  1980年   2063篇
  1979年   2275篇
  1978年   2434篇
  1977年   2439篇
  1976年   3112篇
  1975年   2248篇
  1974年   2307篇
  1973年   2343篇
  1972年   2157篇
  1971年   1911篇
  1970年   1702篇
  1969年   1632篇
排序方式: 共有10000条查询结果,搜索用时 256 毫秒
61.
The authors have determined the causes of drop in performance of induced block caving using fans of blastholes 105 mm in diameter and single blastholes 250 mm in diameter, as well as the sources of increased drilling cost and expansion of start-up time of production blocks in Abakan underground mine. Alternatives of improvement in drilling efficiency under current conditions are discussed.  相似文献   
62.
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   
63.
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   
64.
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   
65.
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   
66.
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   
67.
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   
68.
Senescent cells accumulate in the adipose tissue (AT) of individuals with obesity and secrete multiple factors that constitute the senescence-associated secretory phenotype (SASP). This paper aimed at the identification of B cells with a SASP phenotype in the AT, as compared to the peripheral blood, of individuals with obesity. Our results show increased expression of SASP markers in AT versus blood B cells, a phenotype associated with a hyper-metabolic profile necessary to support the increased immune activation of AT-derived B cells as compared to blood-derived B cells. This hyper-metabolic profile is needed for the secretion of the pro-inflammatory mediators (cytokines, chemokines, micro-RNAs) that fuel local and systemic inflammation.  相似文献   
69.
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   
70.
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   
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