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   70篇
  免费   1篇
化学工业   8篇
金属工艺   1篇
机械仪表   4篇
建筑科学   1篇
轻工业   3篇
水利工程   5篇
石油天然气   1篇
无线电   4篇
一般工业技术   17篇
冶金工业   20篇
原子能技术   5篇
自动化技术   2篇
  2023年   1篇
  2022年   2篇
  2021年   6篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   2篇
  2016年   3篇
  2015年   2篇
  2014年   1篇
  2013年   2篇
  2012年   5篇
  2011年   5篇
  2010年   1篇
  2009年   1篇
  2007年   4篇
  2006年   4篇
  2003年   1篇
  2002年   1篇
  2000年   1篇
  1998年   4篇
  1997年   4篇
  1996年   1篇
  1993年   2篇
  1988年   1篇
  1984年   1篇
  1981年   1篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1972年   1篇
  1970年   1篇
  1958年   3篇
  1957年   2篇
排序方式: 共有71条查询结果,搜索用时 31 毫秒
31.
32.
A compact flat-field soft x-ray grazing-incidence grating spectrometer equipped with a cryogenically cooled back-illuminated charge-coupled device camera was built and implemented at the Heidelberg Electron Beam Ion Trap. The instrument spans the spectral region from 1 to 37 nm using two different gratings. In slitless operation mode, it directly images a radiation source, in this case ions confined in an electron beam ion trap, with high efficiency and reaching hereby a resolving power of lambda/Deltalambda approximately =130 at 2 nm and of lambda/Deltalambda approximately =600 at 28 nm. Capable of automatized operation, its low noise and excellent stability make it an ideal instrument not only for spectroscopic diagnostics requiring wide spectral coverage but also for precision wavelength measurements.  相似文献   
33.
Journal of Nondestructive Evaluation - Centrifugal pumps (CPs) are mainly composed of impeller and bearings. The operation of the CPs is disturbed if any of its components is faulty. Bearings...  相似文献   
34.
The technical solutions proposed for modifying the internal structure of the tundishes in slab continuous casters and intended to increase the quality of slabs and sheet rolled products are subjected to pilot tests.  相似文献   
35.
The Doppler laser flowmetry was used in order to study the microcirculation in the skin, muscles and bone marrow at different stages of obliterating atherosclerosis of the lower extremity arteries. Progress of the disease is characterized by a decrease of the absolute indices of blood flow in combination with disturbed regulation of vascular tension. The lumbar sympathectomy causes intensification of microcirculation not only in the skin, but also in the muscular and bone marrow tissues.  相似文献   
36.
Films of nanocrystalline silicon (nc-Si) were prepared from hydrogenated amorphous silicon (a-Si:H) by using rapid thermal annealing. The formed nc-Si films were subjected to stain etching in hydrofluoric acid solutions in order to passivate surfaces of nc-Si. The optical reflectance spectroscopy revealed the nc-Si formation as well as the high optical quality of the formed films. The Raman scattering spectroscopy was used to estimate the mean size and volume fraction of nc-Si in the annealed films, which were about 4 to 8 nm and 44 to 90%, respectively, depending on the annealing regime. In contrast to as-deposited a-Si:H films, the nc-Si films after stain etching exhibited efficient photoluminescence in the spectral range of 600 to 950 nm at room temperature. The photoluminescence intensity and lifetimes of the stain etched nc-Si films were similar to those for conventional porous Si formed by electrochemical etching. The obtained results indicate new possibilities to prepare luminescent thin films for Si-based optoelectronics.  相似文献   
37.
Physical simulation of steel injection in the intermediate ladle of a continuous slab-casting machine permits the determination of the supply channels for the bottom tuyere such that bubble injection of the metal extends over the whole bath depth in the intermediate ladle and the gas bubbles reliably pass through the slag coating layer. Practical results are presented for the proposed tuyere.  相似文献   
38.
39.
40.
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