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   110570篇
  免费   7858篇
  国内免费   2632篇
电工技术   6019篇
技术理论   8篇
综合类   6316篇
化学工业   17148篇
金属工艺   6609篇
机械仪表   7355篇
建筑科学   8168篇
矿业工程   3469篇
能源动力   3151篇
轻工业   6666篇
水利工程   1698篇
石油天然气   7472篇
武器工业   805篇
无线电   11729篇
一般工业技术   12652篇
冶金工业   8539篇
原子能技术   1201篇
自动化技术   12055篇
  2025年   207篇
  2024年   2526篇
  2023年   2301篇
  2022年   3320篇
  2021年   4511篇
  2020年   3948篇
  2019年   3275篇
  2018年   3128篇
  2017年   3446篇
  2016年   3335篇
  2015年   4271篇
  2014年   5031篇
  2013年   5899篇
  2012年   6298篇
  2011年   6731篇
  2010年   5775篇
  2009年   5529篇
  2008年   5381篇
  2007年   5113篇
  2006年   5412篇
  2005年   4711篇
  2004年   2983篇
  2003年   2849篇
  2002年   2661篇
  2001年   2409篇
  2000年   2324篇
  1999年   2773篇
  1998年   3336篇
  1997年   2403篇
  1996年   2103篇
  1995年   1656篇
  1994年   1345篇
  1993年   981篇
  1992年   692篇
  1991年   491篇
  1990年   398篇
  1989年   337篇
  1988年   257篇
  1987年   195篇
  1986年   146篇
  1985年   94篇
  1984年   58篇
  1983年   51篇
  1982年   57篇
  1981年   51篇
  1980年   45篇
  1979年   17篇
  1977年   65篇
  1976年   113篇
  1953年   6篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Social navigation enables emergent collaboration between independent collaborators by exposing the behavior of each individual. This is a powerful idea for web-based visualization, where the work of one user can inform other users interacting with the same visualization. Results from a crowdsourced user study evaluating the value of such social navigation cues for a geographic map service are presented. Results show significantly improved performance for participants who interacted with the map when the visual footprints of previous users were visible.  相似文献   
42.
Automated separation and classification of touching or overlapping chromosomes in a metaphase image is a critical step in computer-aided chromosome analysis. The advent of the multiplex fluorescence in situ hybridization (M-FISH) technology enables multi-spectral chromosome image with rich spectral information and DAPI image with abundant texture information. This paper presents a fusion classification scheme to improve the segmentation of overlapping and touching chromosomes. First, the texture and spectral information is fused to partition the chromosome cluster into a series of homologous regions. Then a graph-theoretical classification and pairing method is proposed to resolve any remaining ambiguity of the aforementioned separation process. Experiment results demonstrate that the proposed method outperforms conventional multi-spectral classification methods in touching and overlapping chromosome separation.  相似文献   
43.
赵兴文 《小水电》2011,(2):61-62
偏岩水电站在运行过程中由于轴承温度偏高未得到及时正确处理,仅投运8 000 h左右就造成了发电机断轴事故。通过对断轴事故的分析,找出了事故发生的主要原因。图1幅,表1个。  相似文献   
44.
We have shown that dicyanogold(I), [Au(CN)(2)](-) is a common metabolite found in blood and urine samples of patients treated with different gold based drugs. Some patients have high levels of gold within their red blood cells (RBCs). Size exclusion and C18 reversed phase chromatography show that the majority of the gold in RBC lysates is bound to protein, but small molecules such as dicyanogold(I) and gold-glutathione complexes are also present. Dicyanogold incubation with red blood cells in vitro leads to a rapid and complete uptake of gold. This uptake is unaffected by DIDS, an inhibitor of the anion channel, but is blocked by the addition of external cyanide. Dicyanogold is also readily taken up by H9 cells, a continuous CD(4+) cell line. This uptake is significantly inhibited by N-ethylmaleimide, suggesting a requirement for sulfhydryl groups. Dicyanogold inhibits the replication of the AIDS virus, HIV, in a cell culture model.  相似文献   
45.
Zhang J  Etemad S  Zhao JH 《Applied optics》1995,34(28):6500-6505
To our knowledge the concept of an angular conserved grating-pair dispersion compensation system is proposed for the first time, and furthermore a model of such a system is developed and applied to the study of two- and three-lens special cases. A set of easy-to-use dispersion compensation formulas based on geometric optics has been derived and confirmed by our experimental results. Tunability and a compensation ratio as high as 27,600 have been achieved with two- and three-lens systems, respectively.  相似文献   
46.
Bacon AM  Zhao HZ  Wang LJ  Thomas JE 《Applied optics》1995,34(24):5326-5330
We report a simple scheme for sensitive measurements of optical-noise spectra. Optical noise is separated from electronic noise when the output of an analog spectrum analyzer is real-time squared and then lock-in detected. This method directly yields the desired mean-square noise voltage, i.e., the power spectrum of the optical noise on a linear scale. To demonstrate this technique, the mean-square shot noise of a laser beam is measured and found to vary linearly with the laser power from several milliwatts down to one microwatt, in excellent quantitative agreement with predictions.  相似文献   
47.
Lin  Yijun  Wu  Fengge  Zhao  Junsuo 《Neural computing & applications》2023,35(11):8227-8241
Neural Computing and Applications - High-resolution (HR) remote sensing images provide rich information for human activities. However, processing entire HR images is time-consuming, and many...  相似文献   
48.
Neural Computing and Applications - Considering some problems of local linear embedding methods in semi-supervised scenarios, a robust scheme for generating soft labels is designed and a...  相似文献   
49.
The Journal of Supercomputing - The incomplete enforcement of environmental regulation by local governments will lead to environmental degradation. While the strategy selection for local...  相似文献   
50.
Zhang  Tianheng  Zhao  Jianli  Sun  Qiuxia  Zhang  Bin  Chen  Jianjian  Gong  Maoguo 《Applied Intelligence》2022,52(7):7761-7776
Applied Intelligence - In recent years, low-rank tensor completion has been widely used in color image recovery. Tensor Train (TT), as a balanced tensor rank minimization method, has achieved good...  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