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   261080篇
  免费   4278篇
  国内免费   1822篇
电工技术   5415篇
技术理论   5篇
综合类   1164篇
化学工业   42110篇
金属工艺   11026篇
机械仪表   7745篇
建筑科学   6603篇
矿业工程   1661篇
能源动力   5622篇
轻工业   25803篇
水利工程   2890篇
石油天然气   5999篇
武器工业   243篇
无线电   27808篇
一般工业技术   49224篇
冶金工业   47300篇
原子能技术   5618篇
自动化技术   20944篇
  2021年   2487篇
  2019年   2126篇
  2018年   3394篇
  2017年   3363篇
  2016年   3686篇
  2015年   2801篇
  2014年   4584篇
  2013年   11375篇
  2012年   7694篇
  2011年   10206篇
  2010年   8131篇
  2009年   8674篇
  2008年   9481篇
  2007年   9599篇
  2006年   8442篇
  2005年   7390篇
  2004年   6662篇
  2003年   6206篇
  2002年   6212篇
  2001年   6318篇
  2000年   5912篇
  1999年   5877篇
  1998年   12861篇
  1997年   9536篇
  1996年   7279篇
  1995年   5529篇
  1994年   5084篇
  1993年   4951篇
  1992年   3953篇
  1991年   3753篇
  1990年   3832篇
  1989年   3772篇
  1988年   3534篇
  1987年   3023篇
  1986年   3057篇
  1985年   3415篇
  1984年   3328篇
  1983年   3078篇
  1982年   2701篇
  1981年   2908篇
  1980年   2649篇
  1979年   2843篇
  1978年   2740篇
  1977年   2843篇
  1976年   3696篇
  1975年   2461篇
  1974年   2292篇
  1973年   2322篇
  1972年   1982篇
  1971年   1787篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
The effect of the composition of sensitizing–activating solutions on the activation efficiency and the chemical coppering of diamond powders is studied. The results demonstrate that stabilizing additives improve the stability of the solutions, influence the average coppering rate, and play a key role in determining the morphology and quality of the resultant coatings. The most effective stabilizing additive is synthamid-10, which ensures the deposition of high-quality copper coatings.  相似文献   
64.
The TELEMAC project brings new methodologies from the Information and Science Technologies field to the world of water treatment. TELEMAC offers an advanced remote management system which adapts to most of the anaerobic wastewater treatment plants that do not benefit from a local expert in wastewater treatment. The TELEMAC system takes advantage of new sensors to better monitor the process dynamics and to run automatic controllers that stabilise the treatment plant, meet the depollution requirements and provide a biogas quality suitable for cogeneration. If the automatic system detects a failure which cannot be solved automatically or locally by a technician, then an expert from the TELEMAC Control Centre is contacted via the internet and manages the problem.  相似文献   
65.
Polystyrene packaging material taint was sensorily evaluated in cocoa powder for drinks and chocolate flakes using short-cut signal detection measures on differences between control and test samples and on recognition of styrene. No differences were observed in cocoa powder for drinks and plain chocolate flakes treated with 0.5 dm2 polystyrene of 1 mm thickness. However, differences were detected in milk chocolate flakes and plain chocolate flakes, which were in contact with a larger area or thicker polystyrene packaging material. The latter results were confirmed by the styrene recognition test, so polystyrene is a potential source of off-flavour for chocolate products. The amount of residual styrene in the polystyrene used was about 320 ppm, while the amounts of styrene ranged from 7 to 132 ppb in cocoa drinks and from 414 to 1447 ppb in chocolate flakes.  相似文献   
66.
67.
Technology is developed for preparing refractory components made of partially stabilized zirconium dioxide using an isostatic compaction press. Technology is provided for manufacturing dispensing nozzles using combined and separately stabilized zirconium dioxide, and also indices of the refractories obtained and imported materials are compared. __________ Translated from Novye Ogneupory, No. 3, pp. 127–131, March 2008.  相似文献   
68.
Compositions have been developed for nonshrinking vibrocast thermally insulating light refractory concretes with densities of 1.0, 1.3, 1.5, and 1.8 g/cm3 for temperatures of use up to 1400°C. The structure and properties have been examined for the concrete of density 1.3 g/cm3. __________ Translated from Novye Ogneupory, No. 4, pp. 29–32, April, 2008.  相似文献   
69.
Methods are proposed for designing interpolation models for the preliminary determination and subsequent forecasting of general and fractional breakthrough coefficients for dust used with granular filters, as employed in energy-saving and high-performance dust trapping from technological gases and ventilation discharges in refractory production. The models are supplied with nomograms, which makes them widely suitable for experts working in environmental protection at refractory-producing organizations. The main factors are identified that influence the performance. The results are of interest to experts in related areas of industry such as building materials and engineering ceramics and so on. Translated from Novye Ogneupory, No. 4, pp. 64–67, April, 2008.  相似文献   
70.
Results are presented on the corrosion resistance of chromium-bearing refractories of granular structure acted on by corrosive molten slags, metals, and glasses. It is possible to recommend these refractories to customers for particular conditions of use. Chromium-bearing refractories increase the working lives of furnaces considerably. __________ Translated from Novye Ogneupory, No. 1, pp. 55–61, January, 2008.  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