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   1426982篇
  免费   28728篇
  国内免费   7733篇
电工技术   34512篇
技术理论   2篇
综合类   7674篇
化学工业   253650篇
金属工艺   63754篇
机械仪表   40354篇
建筑科学   43394篇
矿业工程   11967篇
能源动力   50194篇
轻工业   99816篇
水利工程   14667篇
石油天然气   37667篇
武器工业   263篇
无线电   194894篇
一般工业技术   270252篇
冶金工业   139895篇
原子能技术   33886篇
自动化技术   166602篇
  2021年   15384篇
  2020年   12404篇
  2019年   15033篇
  2018年   14656篇
  2017年   13962篇
  2016年   20915篇
  2015年   17898篇
  2014年   29538篇
  2013年   88566篇
  2012年   34448篇
  2011年   45513篇
  2010年   41795篇
  2009年   50502篇
  2008年   42818篇
  2007年   39531篇
  2006年   43946篇
  2005年   38115篇
  2004年   40326篇
  2003年   40283篇
  2002年   38168篇
  2001年   33862篇
  2000年   31957篇
  1999年   31331篇
  1998年   35478篇
  1997年   32781篇
  1996年   30351篇
  1995年   28690篇
  1994年   27075篇
  1993年   26884篇
  1992年   25139篇
  1991年   22215篇
  1990年   22726篇
  1989年   21604篇
  1988年   20031篇
  1987年   18434篇
  1986年   17827篇
  1985年   21118篇
  1984年   21589篇
  1983年   19558篇
  1982年   18747篇
  1981年   18793篇
  1980年   17389篇
  1979年   17978篇
  1978年   17279篇
  1977年   16550篇
  1976年   16772篇
  1975年   15564篇
  1974年   15120篇
  1973年   15195篇
  1972年   12741篇
排序方式: 共有10000条查询结果,搜索用时 156 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.
63.
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   
64.
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   
65.
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   
66.
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   
67.
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   
68.
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   
69.
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   
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