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   2998篇
  免费   209篇
  国内免费   2篇
电工技术   88篇
综合类   4篇
化学工业   725篇
金属工艺   63篇
机械仪表   103篇
建筑科学   102篇
矿业工程   8篇
能源动力   118篇
轻工业   502篇
水利工程   15篇
石油天然气   14篇
无线电   192篇
一般工业技术   766篇
冶金工业   44篇
原子能技术   9篇
自动化技术   456篇
  2023年   21篇
  2022年   18篇
  2021年   69篇
  2020年   60篇
  2019年   69篇
  2018年   116篇
  2017年   109篇
  2016年   143篇
  2015年   101篇
  2014年   155篇
  2013年   335篇
  2012年   208篇
  2011年   223篇
  2010年   183篇
  2009年   131篇
  2008年   139篇
  2007年   118篇
  2006年   96篇
  2005年   54篇
  2004年   32篇
  2003年   49篇
  2002年   40篇
  2001年   31篇
  2000年   36篇
  1999年   31篇
  1998年   27篇
  1997年   19篇
  1996年   28篇
  1995年   21篇
  1994年   29篇
  1993年   25篇
  1992年   23篇
  1991年   20篇
  1990年   21篇
  1989年   17篇
  1988年   13篇
  1985年   33篇
  1984年   34篇
  1983年   28篇
  1982年   25篇
  1981年   37篇
  1980年   32篇
  1979年   25篇
  1978年   25篇
  1977年   19篇
  1976年   21篇
  1975年   13篇
  1974年   11篇
  1973年   14篇
  1972年   14篇
排序方式: 共有3209条查询结果,搜索用时 543 毫秒
131.
Existing adaptive control algorithms at best guarantee that the tracking error is a l 2 sequence. This paper presents globally stable adaptive control algorithms for linear discrete-time systems providing l 1 tracking performance. Two algorithms with different degree of complexity are proposed, one for the case of known control directions, and a separate algorithm for the case of unknown control directions. It is demonstrated that in both cases the tracking error is l 1 sequence, while the input and output signals are uniformly bounded.  相似文献   
132.
133.
134.
Neural Computing and Applications - In the paper, the authors elaborate a recent research concerning the originality of artworks in terms of self-organization in the complex systems physics. It has...  相似文献   
135.
136.
137.
138.
In modern wireless ad hoc networks, with a high speed PHY, every collision means a significant loss of useful bandwidth. In the last few years different binary contention protocols have been introduced to address this problem. In this work we propose a novel binary contention protocol called binary priority countdown (BPC) protocol, whose goal is to reduce collisions as well as contention time. BPC uses a new priority countdown mechanism which exploits the efficiency of binary countdown, but the priority countdown process is not constrained to a single binary countdown round. This way, the priority space is not defined by the length of binary countdown round, like in other binary countdown protocols proposed in the literature, and arbitrary medium access priorities can be decremented through multiple binary countdown rounds if necessary. The ability of a new priority countdown mechanism to count down any priority number without changing the length of a binary countdown round, allows independent management of priority space. This “independence” of priority space introduces new optimization and adaptation possibilities. Collision memory effect is recognized and described. BPC protocol reveals connection between unary, binary and digit contention protocols. All three groups of protocols can now be seen as members of the same class of contention algorithms. Preliminary simulation results are shown.  相似文献   
139.
This paper examines the possibilities of enhancing relationship management between public service broadcasters and their stakeholders by harnessing the potential of newest e-business technologies and concepts, such as: social media, digital and interactive TV, and mobile computing. In order to facilitate adoption of relationship management strategy, a framework for leveraging relationship management is proposed. Evaluation was performed within the e-business system of a public broadcaster. This empirical study explored the readiness and expected benefits of relationship management implementation. The research results have indicated that a public broadcaster could achieve a higher level of social responsibility, improve business sustainability, and empower communication and collaboration with all the stakeholders by using emerging technologies for relationship management activities.  相似文献   
140.
The research was conducted with the aim to investigate the possibility of Farinograph, Extensograph and Amylograph values prediction with linear and/or multiple Mixolab regression models. In total, 163 flour samples were divided based on Machalanobis distances into three sets: prediction, validation and external sample set. Determination coefficients ranged from 0.145 to 0.640 for linear regression models and from 0.279 to 0.739 for multiple regression models. Internal and external validation of developed regression models was conducted. Testing of developed models resulted in a high share of samples for which predicted values were out of the ranges of method official reproducibility and a high share of samples for which predicted values were out of the quality level range obtained by analytical measurement. It was concluded that it is impossible to develop applicable regression models for prediction of Farinograph, Extensograph and Amylograph parameters on the basis of Mixolab values from standard protocol.  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