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   562篇
  免费   14篇
  国内免费   1篇
电工技术   7篇
化学工业   127篇
金属工艺   18篇
机械仪表   20篇
建筑科学   5篇
能源动力   12篇
轻工业   43篇
水利工程   2篇
石油天然气   3篇
无线电   45篇
一般工业技术   66篇
冶金工业   123篇
原子能技术   17篇
自动化技术   89篇
  2023年   9篇
  2022年   15篇
  2021年   10篇
  2020年   6篇
  2019年   8篇
  2018年   6篇
  2017年   6篇
  2016年   8篇
  2015年   5篇
  2014年   6篇
  2013年   32篇
  2012年   17篇
  2011年   20篇
  2010年   7篇
  2009年   15篇
  2008年   23篇
  2007年   17篇
  2006年   11篇
  2005年   18篇
  2004年   27篇
  2003年   19篇
  2002年   16篇
  2001年   10篇
  2000年   15篇
  1999年   8篇
  1998年   25篇
  1997年   19篇
  1996年   21篇
  1995年   23篇
  1994年   8篇
  1993年   13篇
  1992年   12篇
  1991年   10篇
  1990年   6篇
  1989年   11篇
  1988年   15篇
  1987年   10篇
  1986年   7篇
  1985年   12篇
  1984年   3篇
  1983年   4篇
  1982年   7篇
  1981年   8篇
  1980年   5篇
  1979年   2篇
  1978年   4篇
  1977年   5篇
  1976年   6篇
  1970年   2篇
  1956年   1篇
排序方式: 共有577条查询结果,搜索用时 15 毫秒
1.
Service composition for generic service graphs   总被引:1,自引:0,他引:1  
Service composition is a promising approach to multimedia service provisioning, due to its ability to dynamically produce new multimedia content, and to customize the content for individual client devices. Previous research work has addressed various aspects of service composition such as composibility, QoS-awareness, and load balancing. However, most of the work has focused on applications where data flow from a single source is processed by intermediate services and then delivered to a single destination. In this paper, we address the service composition problem for multimedia services that can be modeled as directed acyclic graphs (DAGs). We formally define the problem and prove its NP hardness. We also design a heuristic algorithm to solve the problem. Our simulation results show that the algorithm is effective at finding low-cost composition solutions, and can trade off computation overhead for better results. When compared with a hop-by-hop approach for service composition, our algorithm can find composition solutions that aress 10% smaller in cost, even when the hop-by-hop approach uses exhaustive searches.  相似文献   
2.
Mentoring has been around for ages, often masquerading as the management club or the fast track. Among successful business unit managers, mentoring is a well-understood practice, and it's a career development strategy today's IS professional would be wise to consider.  相似文献   
3.
Multi-functional biochip for medical diagnostics and pathogen detection   总被引:2,自引:0,他引:2  
We describe a multi-functional biochip (MFB), which uses two different types of bioreceptors, including nucleic acid and antibody probes, on a single platform. The multi-functional capability of the MFB device for biomedical diagnostics is illustrated by measurements of DNA probes specific to gene fragments of Bacillus anthracis and antibody probes targeted to Escherichia coli. Calibration curves for monitoring pathogenic species using antibody probes against E. coli and DNA probes for B. anthracis illustrate the capability of the device for medical diagnostics and for quantitative detection of pathogenic agents.  相似文献   
4.
    
  相似文献   
5.
Eight countries collaborated and shared technical information on the harvesting of small trees and forest residues in a three year program. Proceedings and reports from workshops and reviews are summarized in a review of activities and harvesting systems of the participating countries. Four databases were developed for harvesting and transportation of these materials.  相似文献   
6.
7.
8.
Electron microscopy is gradually revealing more and more about the structure of the calcium pump from the sarcoplasmic reticulum, Ca(2+)-ATPase. The most recent result reveals the ATP-binding site, and two different avenues are being pursued towards achieving a higher resolution structure. Although no such structures are currently available for phospholamban, various spectroscopies and site-directed mutagenesis have been combined to produce a compelling structural model for its regulation of Ca(2+)-ATPase.  相似文献   
9.
The paper presents recent results in the area of high-power testing aimed at improving the safety of electrical staff working on live equipment. The driver for this work is the American Guide (IEEE 1584) on such exposure hazards, which has the potential for international adoption and, in the authors' opinion, does not provide a suitable methodology for assessing the hazard. A selection of results is presented, obtained in a high-power-system-supplied commercial test laboratory, using the latest charge-coupled device (CCD)-based high-speed video-recording methods. Results are reported for 415-V currents in the range of 1000-70 000 prospective root mean square (rms) amperes and for tests at 5000 V in the range of 1000-27 000 A. The impact of conventional protective devices is included together with some disturbing video results for circuit-breaker-protected systems. The major part of the material in this paper was first presented at the 7th International Conference on Electric Fuses and Their Applications, Jurata, Poland, in 2003.  相似文献   
10.
EFFECTOFTHERATIOTh/UONTLDATINGACCURACY¥P.L.Leung(梁宝鎏);MichaelJ.Stokes(DepartmentofPhysicsandMaterialsScience,CityPolytechnico...  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