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   467篇
  免费   9篇
  国内免费   1篇
电工技术   5篇
综合类   1篇
化学工业   49篇
金属工艺   3篇
机械仪表   11篇
建筑科学   26篇
矿业工程   3篇
能源动力   17篇
轻工业   35篇
水利工程   12篇
石油天然气   2篇
无线电   65篇
一般工业技术   66篇
冶金工业   56篇
原子能技术   3篇
自动化技术   123篇
  2023年   1篇
  2022年   1篇
  2021年   6篇
  2020年   3篇
  2019年   7篇
  2018年   8篇
  2017年   5篇
  2016年   10篇
  2015年   1篇
  2014年   7篇
  2013年   29篇
  2012年   22篇
  2011年   26篇
  2010年   22篇
  2009年   35篇
  2008年   33篇
  2007年   30篇
  2006年   30篇
  2005年   28篇
  2004年   15篇
  2003年   16篇
  2002年   11篇
  2001年   7篇
  2000年   17篇
  1999年   11篇
  1998年   8篇
  1997年   6篇
  1996年   7篇
  1995年   7篇
  1994年   5篇
  1993年   6篇
  1992年   1篇
  1991年   2篇
  1990年   2篇
  1989年   9篇
  1988年   3篇
  1987年   8篇
  1986年   3篇
  1985年   8篇
  1984年   2篇
  1983年   4篇
  1982年   3篇
  1981年   3篇
  1977年   3篇
  1976年   3篇
  1975年   1篇
  1973年   1篇
  1967年   1篇
排序方式: 共有477条查询结果,搜索用时 31 毫秒
51.
52.
53.
Smart metering: The holy grail of demand-side energy management?   总被引:1,自引:0,他引:1  
  相似文献   
54.
An experimental procedure is summarized to calculate automobile fuel consumption in the work trip and to indicate the implications of evaluating alternative subdivision street layouts. The results of the Residential Area Traffic Analysis Model show that annual fuel consumption increases with vehicle weight. The paper concludes that annual cost savings in fuel consumption and other benefits are realized by commuters who drive lighter cars.  相似文献   
55.
56.
57.
A rapid, high-throughput antimicrobial screening assay was developed using either a physical fluid extraction or a solvent extraction technique coupled to the commercially available Premi®Test. The solvent extraction approach was fully validated for a wide range of tissues and the fluid extraction approach partially validated for porcine muscle. Both procedures can detect a wide range of antimicrobial compounds at or below maximum residue limit concentrations. The use of a solvent extraction provides an enhanced test capable of detecting a wider range of drugs than the fluid extraction approach at or below half maximum residue limit levels in a variety of matrices. Biochemical methods for the class-specific identification of β-lactams and sulphonamides following initial screening were developed and validated. The approach is a significant improvement on existing methodologies as a tool for residues monitoring in surveillance programmes.  相似文献   
58.
The paper presents a theoretical analysis of condenation of a saturated vapour on the outside of a vertical cylinder. Particular attention is focussed on the effect of including surface tension. The analysis is developed in terms of perturbation approximations and solutions obtained by perturbation theory are discussed in comparison with numerical solutions. The results show that surface tension plays a very significant role when the radius of the cylinder is small.  相似文献   
59.
The performance of Napier et al.'s typist verification algorithm (Keyboard user verification: toward an accurate, efficient, and ecologically valid algorithm, International Journal of Human-Computer Studies 43 (1995) 213-222) was assessed in a text-dependent setting. Twenty-nine subjects typed a 17 character password 50 times. False acceptance and false rejection rates were then calculated as the number of repetitions of the password included in the reference profile was increased from 6 to 20 and the number of digraphs from the password included in the verification process was increased from 2 to 16. The performance of the system (12% total error rate) was found to be comparable with the best results reported in other studies using text-dependent algorithms, and substantially better than that reported in studies using a text-independent paradigm with passwords of this length. The relationship between password length and reference profile size was found to conform to an exponential decay function, which accounted for 92% of the variability in verification error rates.  相似文献   
60.
The effect of interfacial crosslinking on miscibility behavior in blend systems of isocyanate‐functionalized poly(n‐butyl methacrylate) (PBMA) and a carboxylic alkali‐soluble resin, poly(styrene/alpha‐methylstyrene/acrylic acid) (SAA), was studied with different dimethyl meta‐isopropenyl benzyl isocyanate (TMI) concentrations. For the blend films of pure PBMA and SAA, both theoretical analysis and direct observation showed immiscibility between PBMA and SAA. For the blend systems of isocyanated PBMA and SAA, Fourier transform infrared spectra and gel permeation chromatography analyses qualitatively showed the crosslinking between the isocyanate group in isocyanated PBMA and the carboxylic group in SAA. Two tan δ peaks were shown in the blend system of SAA and isocyanated PBMA containing low concentrations of TMI (from 0 to 5 wt %), and the span of the two peaks became shorter as the TMI concentration increased. For a high TMI concentration (7 wt %), only one tan δ peaks was observed. This result means the interfacial crosslinking between isocyanated PBMA and SAA occurred fully, and thus the miscibility between two polymers was significantly improved. As these results showed, the tensile strength of the blend film of isocyanated PBMA and SAA was higher than that of pure PBMA and SAA. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 792–798, 2003  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