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   553篇
  免费   10篇
  国内免费   2篇
电工技术   6篇
综合类   2篇
化学工业   95篇
金属工艺   9篇
机械仪表   8篇
建筑科学   20篇
矿业工程   3篇
能源动力   33篇
轻工业   32篇
水利工程   1篇
石油天然气   5篇
无线电   65篇
一般工业技术   83篇
冶金工业   126篇
原子能技术   2篇
自动化技术   75篇
  2021年   12篇
  2020年   11篇
  2019年   9篇
  2018年   13篇
  2017年   6篇
  2016年   7篇
  2015年   9篇
  2014年   11篇
  2013年   33篇
  2012年   16篇
  2011年   26篇
  2010年   25篇
  2009年   15篇
  2008年   15篇
  2007年   21篇
  2006年   21篇
  2005年   7篇
  2004年   14篇
  2003年   11篇
  2002年   10篇
  2001年   4篇
  2000年   11篇
  1999年   6篇
  1998年   16篇
  1997年   10篇
  1996年   14篇
  1995年   12篇
  1994年   10篇
  1993年   6篇
  1992年   16篇
  1990年   13篇
  1989年   5篇
  1988年   7篇
  1987年   8篇
  1986年   11篇
  1985年   14篇
  1984年   9篇
  1983年   7篇
  1982年   5篇
  1981年   10篇
  1980年   6篇
  1979年   7篇
  1978年   7篇
  1976年   4篇
  1975年   4篇
  1970年   4篇
  1969年   3篇
  1966年   3篇
  1964年   3篇
  1958年   3篇
排序方式: 共有565条查询结果,搜索用时 15 毫秒
1.
We have used a series of singular expansion functions to represent the potential across the gap of a shielded pole head in the presence of a highly permeable underlayer. This method of analysis reduces the size of the system of equations to be solved for the series coefficients to the number of coefficients that will be used. Just two series terms suffice to evaluate the magnetic potential to within 1% of the pole potential at any point on the air-bearing surface for a large range of head dimensions. Here, we express the surface field spectrum analytically. Including just two series terms provides an excellent estimate.  相似文献   
2.
Pervasive computing is as much about the user as it is about the technology. So, the Fifth International Conference on Pervasive Computing emphasized desirability rather than just feasibility. Featured themes included user benefits, human-computer interaction, group and social interactions, context awareness, finding and positioning people and objects, and personal privacy.  相似文献   
3.
4.
5.
6.
7.
From the start of industrial biotechnology, there has been a perception that biological entities are damaged by stirring, so-called ‘shear damage'. Often, it was the soft option to explain a loss of performance when it was due to other factors, such as bubble ingestion with proteins or on scale-up, where tip speed increased when it was due to decreased homogeneity, especially in pH. For many years, poor control and the range of analytical tools available made a more in-depth explanation difficult; and the concepts of ‘high' and ‘low shear' impellers, now largely disproven, increased it. Here, the size of the biological entity is compared to the Kolmogorov microscale of turbulence leading to a reasonably clear picture emerging. The article starts with the author's introduction to the issue approximately 42 year ago with enzymes, conveniently also the smallest entity; and finishes with the largest, filamentous fungi.  相似文献   
8.
保证所有管道中石油从一端流向另一端不泄漏要比它的探测更加困难。比较图中的3个系统,可以看到这项技术在40多年来是如何逐步发展的。  相似文献   
9.
In today’s smart city transportation, traffic congestion is a vexing issue, and vehicles seeking parking spaces have been identified as one of the causes leading to approximately 40% of traffic congestion. Identifying parking spaces alone is insufficient because an identified available parking space may have been taken by another vehicle when it arrives, resulting in the driver’s frustration and aggravating traffic jams while searching for another parking space. This explains the need to predict the availability of parking spaces. Recently, deep learning (DL) has been shown to facilitate drivers to find parking spaces efficiently, leading to a promising performance enhancement in parking identification and prediction systems. However, no work reviews DL approaches applied to solve parking identification and prediction problems. Inspired by this gap, the purpose of this work is to investigate, highlight, and report on recent advances in DL approaches applied to predict and identify the availability of parking spaces. A taxonomy of DL-based parking identification and prediction systems is established as a methodology by classifying and categorizing existing literature, and by doing so, the salient and supportive features of different DL techniques for providing parking solutions are presented. Moreover, several open research challenges are outlined. This work identifies that there are various DL architectures, datasets, and performance measures used to address parking identification and prediction problems. Moreover, there are some open-source implementations available that can be used directly either to extend existing works or explore a new domain. This is the first short survey article that focuses on the use of DL-based techniques in parking identification and prediction systems for smart cities. This study concludes that although the deployment of DL in parking identification and prediction systems provides various benefits, the convergence of these two types of systems and DL brings about new issues that must be resolved in the near future.  相似文献   
10.
A safe flight starts with effective performance of the pre-flight flight planning and briefing task. However, several problems related to the execution of this task can be identified. Potentially, the introduction of an improved flight plan provides an opportunity to improve the quality and availability of information provided to Flight Crew, thereby enhancing the quality of crew briefings. The proposed risk-based, intelligent flight plan is designed from the perspective of the current operational concept (e.g. fixed routes and ATC managerial role for separation), and associated airline Flight Planning and Dispatch functions. In this case, the focus is sharing information across specific airline stakeholders (e.g. Flight Operations Management and Safety functions) and Maintenance, to support a safe and efficient flight operation. Overall, the introduction of this new flight plan will result in the definition of new operational and organisational processes, along with a new way of performing the pre-flight, planning and briefing task. It is anticipated that this will impact positively on the operational and safety outcome of the flight.  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