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   1443271篇
  免费   27265篇
  国内免费   6925篇
电工技术   33445篇
综合类   6347篇
化学工业   252201篇
金属工艺   62948篇
机械仪表   40487篇
建筑科学   42626篇
矿业工程   11275篇
能源动力   49660篇
轻工业   107085篇
水利工程   14853篇
石油天然气   36254篇
武器工业   130篇
无线电   193726篇
一般工业技术   275187篇
冶金工业   151120篇
原子能技术   33720篇
自动化技术   166397篇
  2021年   14483篇
  2020年   11775篇
  2019年   14565篇
  2018年   14445篇
  2017年   13650篇
  2016年   20720篇
  2015年   17181篇
  2014年   28576篇
  2013年   87528篇
  2012年   34712篇
  2011年   46368篇
  2010年   41348篇
  2009年   49876篇
  2008年   43554篇
  2007年   40568篇
  2006年   44332篇
  2005年   38643篇
  2004年   40986篇
  2003年   40271篇
  2002年   37874篇
  2001年   34652篇
  2000年   32486篇
  1999年   31836篇
  1998年   39593篇
  1997年   35155篇
  1996年   31454篇
  1995年   29373篇
  1994年   27618篇
  1993年   27446篇
  1992年   25360篇
  1991年   22524篇
  1990年   22910篇
  1989年   21773篇
  1988年   20397篇
  1987年   18685篇
  1986年   18153篇
  1985年   21520篇
  1984年   21866篇
  1983年   19848篇
  1982年   18884篇
  1981年   18941篇
  1980年   17571篇
  1979年   18193篇
  1978年   17412篇
  1977年   16907篇
  1976年   17322篇
  1975年   15714篇
  1974年   15268篇
  1973年   15362篇
  1972年   12878篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
61.
Food- and waterborne viruses, such as human norovirus, hepatitis A virus, hepatitis E virus, rotaviruses, astroviruses, adenoviruses, and enteroviruses, are major contributors to all foodborne illnesses. Their small size, structure, and ability to clump and attach to inanimate surfaces make viruses challenging to reduce or eliminate, especially in the presence of inorganic or organic soils. Besides traditional wet and dry methods of disinfection using chemicals and heat, emerging physical nonthermal decontamination techniques (irradiation, ultraviolet, pulsed light, high hydrostatic pressure, cold atmospheric plasma, and pulsed electric field), novel virucidal surfaces, and bioactive compounds are examined for their potential to inactivate viruses on the surfaces of foods or food contact surfaces (tools, equipment, hands, etc.). Every disinfection technique is discussed based on its efficiency against viruses, specific advantages and disadvantages, and limitations. Structure, genomic organization, and molecular biology of different virus strains are reviewed, as they are key in determining these techniques effectiveness in controlling all or specific foodborne viruses. Selecting suitable viral decontamination techniques requires that their antiviral mechanism of action and ability to reduce virus infectivity must be taken into consideration. Furthermore, details about critical treatments parameters essential to control foodborne viruses in a food production environment are discussed, as they are also determinative in defining best disinfection and hygiene practices preventing viral infection after consuming a food product.  相似文献   
62.
Cybernetics and Systems Analysis - The authors propose a new method for finding the sum of two or more multidigit values in a parallel computational model. The method reduces finding the sum of a...  相似文献   
63.
Compositional analysis of boron carbide on nanometer length scales to examine or interpret atomic mechanisms, for example, solid-state amorphization or grain-boundary segregation, is challenging. This work reviews advancements in high-resolution microanalysis to characterize multiple generations of boron carbide. First, ζ-factor microanalysis will be introduced as a powerful (scanning) transmission electron microscopy ((S)TEM) analytical framework to accurately characterize boron carbide. Three case studies involving the application of ζ-factor microanalysis will then be presented: (1) accurate stoichiometry determination of B-doped boron carbide using ζ-factor microanalysis and electron energy loss spectroscopy, (2) normalized quantification of silicon grain-boundary segregation in Si-doped boron carbide, and (3) calibration of a scanning electron microscope X-ray energy-dispersive spectroscopy (XEDS) system to measure compositional homogeneity differences of B/Si-doped arc-melted boron carbides in the as-melted and annealed conditions. Overall, the improvement and application of advanced analytical tools have helped better understand processing–microstructure–property relationships and successfully manufacture high-performance ceramics.  相似文献   
64.
Journal of Applied Electrochemistry - Organic corrosion inhibitors have become competent alternatives to hazardous chrome conversion coatings due to their rapid adsorption over metal surfaces in...  相似文献   
65.
Russian Engineering Research - Systems are considered for the dehydration of petroleum so as to separate water–petroleum emulsions. In particular, the low-temperature microwave (UHF)...  相似文献   
66.
Wireless Personal Communications - Nowadays, Wireless Sensor Networks (WSNs) is enhancing for different applications. Simultaneously, energy consumption for processing the tasks in most of the...  相似文献   
67.
Journal of Engineering Physics and Thermophysics - A simulation of the vibroacoustic processes proceeding in a long pipe with an obstacle in the form of a circular cylinder, in which a fluid flows,...  相似文献   
68.
Lyzlova  E. V.  Glukhova  A. V.  Konnikov  A. V.  Dyug  K. O. 《Radiochemistry》2022,64(2):176-182
Radiochemistry - The sorption extraction of Pu and Am from nitric acid simulation solutions were studied on a solid extractant (TVEX) AXIONIT MND 40T in a static mode. It is shown that the...  相似文献   
69.
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