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   861篇
  免费   51篇
  国内免费   4篇
电工技术   11篇
综合类   2篇
化学工业   213篇
金属工艺   21篇
机械仪表   23篇
建筑科学   43篇
矿业工程   7篇
能源动力   32篇
轻工业   92篇
水利工程   10篇
石油天然气   5篇
无线电   96篇
一般工业技术   171篇
冶金工业   66篇
原子能技术   5篇
自动化技术   119篇
  2024年   3篇
  2023年   8篇
  2022年   11篇
  2021年   27篇
  2020年   26篇
  2019年   24篇
  2018年   27篇
  2017年   31篇
  2016年   29篇
  2015年   30篇
  2014年   32篇
  2013年   63篇
  2012年   46篇
  2011年   67篇
  2010年   40篇
  2009年   37篇
  2008年   35篇
  2007年   39篇
  2006年   34篇
  2005年   24篇
  2004年   14篇
  2003年   24篇
  2002年   17篇
  2001年   13篇
  2000年   7篇
  1999年   15篇
  1998年   18篇
  1997年   16篇
  1996年   10篇
  1995年   9篇
  1994年   10篇
  1993年   7篇
  1992年   7篇
  1991年   6篇
  1990年   9篇
  1989年   5篇
  1988年   5篇
  1987年   10篇
  1986年   3篇
  1985年   6篇
  1983年   4篇
  1982年   4篇
  1980年   4篇
  1979年   5篇
  1976年   6篇
  1973年   4篇
  1972年   5篇
  1932年   3篇
  1931年   5篇
  1929年   2篇
排序方式: 共有916条查询结果,搜索用时 406 毫秒
71.
In this paper, a human action recognition method is presented in which pose representation is based on the contour points of the human silhouette and actions are learned by making use of sequences of multi-view key poses. Our contribution is twofold. Firstly, our approach achieves state-of-the-art success rates without compromising the speed of the recognition process and therefore showing suitability for online recognition and real-time scenarios. Secondly, dissimilarities among different actors performing the same action are handled by taking into account variations in shape (shifting the test data to the known domain of key poses) and speed (considering inconsistent time scales in the classification). Experimental results on the publicly available Weizmann, MuHAVi and IXMAS datasets return high and stable success rates, achieving, to the best of our knowledge, the best rate so far on the MuHAVi Novel Actor test.  相似文献   
72.
This work proposes a reusable architecture that enables the self-configuration of a supporting infrastructure for Web server clusters using virtual machines. The goal of the architecture is to ensure service quality, evaluating how broadly it complies with the application's operating restrictions and proportionally acting on the configuration of physical servers (hosts) or virtual machines. In addition, through the rational use of resources, the proposal aims at saving energy. A prototype of the architecture was developed and a performance evaluation carried out with two different resource management approaches. This evaluation shows how fully functional and advantageous the proposal is in terms of using resources, avoiding waste, yet maintaining the application's quality of service within acceptable levels. The architecture also shows to be flexible enough to accept, with a reasonable amount of effort, different resource self-configuration policies.  相似文献   
73.
本文基于SOI技术,开发了一款新型的600V/0.3A 6-pack IGBT/MOSFET驱动器芯片.此款名为6ED003L06-F的芯片集成了三相电平转换、门极驱动和电路保护等诸多特性,在缩小芯片尺寸的同时也提高了性能,例如抗反相瞬态电压的鲁棒性等。另外,本文还利用该SOI驱动芯片开发了SmartPACK/SmartPIM系列新型IPM模块,该模块在一块基于DCB层的底板上集成了SOI驱动器,600V IGBT3和自举功能,并且无须支承板。这种IPM可对应6A-12A的额定电流,同时具有结构紧凑、成本低廉、操作简单等优点,适用于各类小功率驱动特别是消费类驱动应用。  相似文献   
74.
75.
    
Ohne Zusammenfassung  相似文献   
76.
    
Ohne Zusammenfassung  相似文献   
77.
78.
Extracts obtained by supercritical carbon dioxide extraction of cones and leaves of hop (Humulus lupulus L) at different combinations of temperature and pressure were analysed for their α- and β-acids and volatiles, using HPLC and GC respectively. The yield and composition of the mixtures of bitter compounds from the cones were largely influenced by the temperature and pressure applied during the extraction. Bitter compounds could not be detected in the extracts from the leaves. The most important volatile components identified were β-myrcene, β-caryophyllene and α-humulene. The extraction parameters also influenced the composition of the mixture of volatiles from the cones and leaves, 40°C and 20.0 MPa being optimum for the extraction of both bitter compounds and volatiles, which are thought to be important for the aroma of beer.  相似文献   
79.
80.
This paper presents a study on the influence of nonideal sampling in asynchronous Q-factor monitoring. An overestimation of the Q-factor of signals impaired with optical noise may occur if the averaging effects due to nonideal sampling affect only the noise component of the monitored signal. It is shown that this problem can be rectified using a correction factor, dependent only on the receiver parameters. This allows reasonable Q-factor estimates using sampling systems with aperture times close to the monitored signal bit period. Nonideal sampling may also affect the signal component of the monitored signal. For such cases, a novel and accurate technique is presented to estimate the Q factor using asynchronous histograms, which takes into account changes in the shape of the monitored signal due to averaging effects. Numerical simulations are used to evaluate the proposed technique achieving Q-factor estimates within a 14% error margin, independently of the sampling aperture for the considered range. Distortion affecting the signal due to the transmission system can also be handled by the new technique presented in this paper. It is verified that the impact of intersymbol interference due to chromatic dispersion or electrical filtering in the receiver on the performance of the system is well reflected by the estimated Q factor.  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