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   2316篇
  免费   103篇
  国内免费   8篇
电工技术   23篇
综合类   3篇
化学工业   590篇
金属工艺   33篇
机械仪表   49篇
建筑科学   83篇
矿业工程   5篇
能源动力   97篇
轻工业   251篇
水利工程   38篇
石油天然气   10篇
无线电   171篇
一般工业技术   331篇
冶金工业   241篇
原子能技术   14篇
自动化技术   488篇
  2024年   5篇
  2023年   33篇
  2022年   95篇
  2021年   119篇
  2020年   78篇
  2019年   65篇
  2018年   69篇
  2017年   76篇
  2016年   80篇
  2015年   79篇
  2014年   68篇
  2013年   155篇
  2012年   157篇
  2011年   158篇
  2010年   106篇
  2009年   114篇
  2008年   99篇
  2007年   101篇
  2006年   93篇
  2005年   79篇
  2004年   64篇
  2003年   43篇
  2002年   52篇
  2001年   28篇
  2000年   16篇
  1999年   28篇
  1998年   59篇
  1997年   39篇
  1996年   25篇
  1995年   18篇
  1994年   17篇
  1993年   19篇
  1992年   8篇
  1991年   14篇
  1990年   8篇
  1989年   18篇
  1988年   8篇
  1987年   14篇
  1986年   12篇
  1985年   7篇
  1984年   11篇
  1983年   10篇
  1981年   8篇
  1980年   17篇
  1979年   4篇
  1977年   5篇
  1976年   10篇
  1975年   4篇
  1974年   7篇
  1972年   4篇
排序方式: 共有2427条查询结果,搜索用时 15 毫秒
31.
32.
33.
When a realistic modelling of radioactive contaminant transport in flowing groundwater is required, very large systems of coupled partial and ordinary differential equations can arise that have to be solved numerically. For that purpose, the software package \(r^3t\) is developed in which several advanced numerical methods are implemented to solve such models efficiently and accurately. Using software tools of \(r^3t\) one can treat successfully nontrivial mathematical problems like advection-dominated system with different retardation of transport for each component and with nonlinear Freundlich sorption and/or precipitation. Additionally, long time simulations on complex 3D geological domains using unstructured grids can be realized. In this paper we introduce and summarize the most important and novel features of numerical simulation for radioactive contaminant transport in porous media when using \(r^3t\).  相似文献   
34.
As telecommunication networks evolve rapidly in terms of scalability, complexity, and heterogeneity, the efficiency of fault localization procedures and the accuracy in the detection of anomalous behaviors are becoming important factors that largely influence the decision making process in large management companies. For this reason, telecommunication companies are doing a big effort investing in new technologies and projects aimed at finding efficient management solutions. One of the challenging issues for network and system management operators is that of dealing with the huge amount of alerts generated by the managed systems and networks. In order to discover anomalous behaviors and speed up fault localization processes, alert correlation is one of the most popular resources. Although many different alert correlation techniques have been investigated, it is still an active research field. In this paper, a survey of the state of the art in alert correlation techniques is presented. Unlike other authors, we consider that the correlation process is a common problem for different fields in the industry. Thus, we focus on showing the broad influence of this problem. Additionally, we suggest an alert correlation architecture capable of modeling current and prospective proposals. Finally, we also review some of the most important commercial products currently available.  相似文献   
35.
Entanglement in high-dimensional many-body systems plays an increasingly vital role in the foundations and applications of quantum physics. In the present paper, we introduce a theoretical concept which allows to categorize multipartite states by the number of degrees of freedom being entangled. In this regard, we derive computable and experimentally friendly criteria for arbitrary multipartite qudit systems that enable to examine in how many degrees of freedom a mixed state is genuine multipartite entangled.  相似文献   
36.
37.
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   
38.
39.
40.
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