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   395篇
  免费   18篇
  国内免费   2篇
化学工业   37篇
金属工艺   5篇
机械仪表   11篇
建筑科学   14篇
能源动力   7篇
轻工业   98篇
水利工程   8篇
石油天然气   1篇
无线电   47篇
一般工业技术   77篇
冶金工业   43篇
自动化技术   67篇
  2022年   4篇
  2021年   10篇
  2020年   3篇
  2019年   3篇
  2018年   10篇
  2017年   7篇
  2016年   7篇
  2015年   9篇
  2014年   13篇
  2013年   30篇
  2012年   27篇
  2011年   32篇
  2010年   15篇
  2009年   12篇
  2008年   22篇
  2007年   30篇
  2006年   27篇
  2005年   26篇
  2004年   28篇
  2003年   23篇
  2002年   22篇
  2001年   1篇
  2000年   2篇
  1999年   9篇
  1998年   6篇
  1997年   3篇
  1996年   6篇
  1995年   7篇
  1994年   5篇
  1993年   2篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1985年   3篇
  1983年   1篇
  1981年   2篇
  1978年   1篇
  1977年   1篇
排序方式: 共有415条查询结果,搜索用时 15 毫秒
101.
The computer hacker is one of the most vilified figures in the digital era, but to what degree are organizations actually responsible for compromised personal records? To examine the role of organizational behavior in privacy violations, we analyze 589 incidents of compromised data between 1980 and 2006. There were more reported incidents in 2005 and 2006 than in the previous 25 years combined. Excluding a particularly large security breach at Acxiom, hackers account for the largest volume of compromised records, some 45%, while 27% of the volume is attributed to organizational mismanagement and 28% remains unattributed. In terms of incidents, 9% were an unspecified type of breach, 31% of the incidents involved hackers, and 60% of the incidents involved organizational mismanagement: personally identifiable information accidentally placed online, missing equipment, lost backup tapes, or other administrative errors. Options for public policy oversight are discussed.  相似文献   
102.
Cross border co-operation is increasingly viewed as an obvious and logical consequence of an integrated perspective on river management. Consequently, we would expect an increase of cross border co-operation and collaboration in EU member states, through joint planning, co-management or co-implementation in flooding policies, water quality management or river rehabilitation. If we take a closer look at regional practices along member states’ borders however, co-operation is often considered as problematic. To explain this discrepancy it is important to look at the conditions of ‘successful’ co-operation in actual cross border initiatives. We provide a framework to analyse regional initiatives, focusing on the extent of co-operation and differences and similarities in policy arrangements. We apply this framework to three cases at the Dutch–German border and conclude that the nature of the problem structure and related interdependencies and ‘urgency’ (still) are important. Moreover, we stress the importance of policy styles and especially the problematic transition from policy formulation to policy implementation in water management.  相似文献   
103.
Children commonly observe and pitch in to ongoing activities in Indigenous communities of Mexico, according to ethnographic research. The present study examines the generality of this approach to learning by comparing its use among Mexican immigrants of two cultural backgrounds in the United States. Results showed more sustained attention to (and learning from) instruction directed to another person by 22 U.S. Mexican-heritage 6- to 11-year-old children whose families likely have experience with Indigenous practices (and limited involvement in Western schooling), compared with 16 U.S. Mexican-heritage children whose families have extensive involvement in Western schooling (and related practices). (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
104.
Summary A computerized databank of IEF protein patterns for use in identifying flatfish species (in total 17 species, including 15 commercial ones) is presented. The databank includes all species regulated by the Belgian Law (22 May 1996) on the use of official names for fishes and seafood products. It was found that interspecimen similarity of the IEF patterns, as processed by digitization, was always larger than interspecies similarity, which allows for unequivocal authentication of unknown samples, as long as the authentic pattern is available in the databank. The databank was used to authenticate 17 commercial fish fillets.  相似文献   
105.
106.
A nine-aperture, wide-field Fizeau imaging telescope has been built at the Lockheed-Martin Advanced Technology Center. The telescope consists of nine, 125 mm diameter collector telescopes coherently phased and combined to form a diffraction-limited image with a resolution that is consistent with the 610 mm diameter of the telescope. The phased field of view of the array is 1 murad. The measured rms wavefront error is 0.08 waves rms at 635 nm. The telescope is actively controlled to correct for tilt and phasing errors. The control sensing technique is the method known as phase diversity, which extracts wavefront information from a pair of focused and defocused images. The optical design of the telescope and typical performance results are described.  相似文献   
107.
108.
The exposure of engineering students to relationships between technology and society has become an accepted component of undergraduate engineering curricula in North America, yet how to present the subject in a way that is stimulating and relevant to engineering students remains a challenge. At the University of Manitoba, various approaches have been taken over several years. This paper outlines a course format and content which has been well received by students. The framework of the course encompasses three main principles. First, technology is presented as having three aspects—technical, cultural, and organizational. Second, the topic is treated within a time-related context—past, present, and future. Past and present are illustrated by examples of technology, their societal impacts, and related cultural and ethical issues. The future is examined using a systems approach for understanding the long-term consequences of human activities and by discussion of the role of technology in reaching global sustainability. Third, the course emphasizes active student involvement through individual and group research and writing, and group discussions and presentation.  相似文献   
109.
110.
This study examined the impact of traffic calming measures (TCM) on major roads in rural and urban areas. More specifically we investigated the effect of gate constructions located at the entrance of the urban area and horizontal curves within the urban area on driving behavior and workload. Forty-six participants completed a 34 km test-drive on a driving simulator with eight thoroughfare configurations, i.e., 2 (curves: present, absent) × 2 (gates: present, absent) × 2 (peripheral detection task (PDT): present, absent) in a within-subject design.  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