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   100383篇
  免费   8108篇
  国内免费   4324篇
电工技术   5646篇
技术理论   6篇
综合类   6355篇
化学工业   16744篇
金属工艺   6216篇
机械仪表   6994篇
建筑科学   8158篇
矿业工程   3422篇
能源动力   2928篇
轻工业   6341篇
水利工程   1688篇
石油天然气   7370篇
武器工业   811篇
无线电   10798篇
一般工业技术   11663篇
冶金工业   4929篇
原子能技术   1025篇
自动化技术   11721篇
  2024年   452篇
  2023年   1785篇
  2022年   3154篇
  2021年   4325篇
  2020年   3354篇
  2019年   2723篇
  2018年   2950篇
  2017年   3307篇
  2016年   3068篇
  2015年   4146篇
  2014年   4961篇
  2013年   5887篇
  2012年   6369篇
  2011年   6795篇
  2010年   5841篇
  2009年   5570篇
  2008年   5408篇
  2007年   5127篇
  2006年   5450篇
  2005年   4741篇
  2004年   3013篇
  2003年   2842篇
  2002年   2670篇
  2001年   2437篇
  2000年   2357篇
  1999年   2663篇
  1998年   2102篇
  1997年   1741篇
  1996年   1716篇
  1995年   1418篇
  1994年   1167篇
  1993年   742篇
  1992年   650篇
  1991年   441篇
  1990年   350篇
  1989年   303篇
  1988年   231篇
  1987年   153篇
  1986年   123篇
  1985年   71篇
  1984年   53篇
  1983年   44篇
  1982年   41篇
  1981年   28篇
  1980年   25篇
  1979年   16篇
  1978年   1篇
  1965年   1篇
  1959年   2篇
  1951年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Wei  Shikui  Jiang  Su  Jin  Wenxian  Zhao  Yao  Ni  Rongrong  Zhu  Zhenfeng 《Multimedia Systems》2015,21(2):207-216
Multimedia Systems - Recently, the frame fusion based video copy detection scheme provides a possibility to detect copies in a continuous query video stream. However, its computational complexity...  相似文献   
92.
93.
94.
95.
96.
为促进S1000D标准在以信息化为中心的综合保障技术中的应用,提高装备技术文档制作和发布的正确性和效率,文章研究了S1000D标准对PDF格式发布样式的规定,分析了XSL的工作原理和各类技术信息的Schema模式,利用XSL-FO技术编写了把数据模块发布成PDF格式的XML文档,通过XMLSPY实现了技术文档的发布;通过实例展示了实现规定的发布样式的关键技术以及从数据模块到PDF发布样式的显示效果,证明了所用方法的正确性与实用性,为实现S1000D标准下的技术信息发布提供了新的可行方法.  相似文献   
97.
Floc architecture of bioflocculation sediment by ESEM and CLSM   总被引:1,自引:0,他引:1  
Huiming Z  Hongwei F  Minghong C 《Scanning》2011,33(6):437-445
Sediment flocculation is a critical component for the understanding of cohesive sediment dynamics. Traditionally, the referred study has largely been devoted to forming mechanism, influencing factors and physicochemical sediment conditions of all kinds of organic-flocculation and inorganic-flocculation. However, during the last decade, the bioflocculation of sediment by biological activity has been given increasing attention. But most studies have focused on the interrelations between biological and sedimentological variables. With the assistance of a newly developed field kit and correlative microscopy (which includes environmental scanning electron microscopy and confocal laser scanning microscopy), this article begins to bridge the resolution gap between sediment particles and biological activities as well as its metabolic products biofilm, in order to better understand the role of polymeric material biofilm in floc ultrastructure and outward floc behavior of bioflocculation sediment. Results have demonstrated that bioflocculation sediment was observed to be composed of complex networks of biofilm and appeared to be of complicated physical floc structures. The biofilm was found to embed particles and permeate the void space, representing the dominant physical bridging mechanism of the flocs and contributed to the extensive surface area, architecture characteristics, and mechanical properties of bioflocculation sediment.  相似文献   
98.
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   
99.
To bring computer vision closer to human vision, we attempt to enable computer to understand the occlusion relationship in an image. In this paper, we propose five low dimensional region-based occlusion cues inspired by the human perception of occlusion. These cues are semantic cue, position cue, compactness cue, shared boundary cue and junction cue. We apply these cues to predict the region-wise occlusion relationship in an image and infer the layer sequence of the image scene. A preference function, trained with samples consisting of these cues, is defined to predict the occlusion relationship in an image. Then we put all the occlusion predictions into the layering algorithm to infer the layer sequence of the image scene.The experiments on rural, artificial and outdoor scene datasets show the effectiveness of our method for occlusion relationship prediction and image scene layering.  相似文献   
100.
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   
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