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   1687篇
  免费   46篇
  国内免费   10篇
电工技术   19篇
化学工业   284篇
金属工艺   44篇
机械仪表   91篇
建筑科学   49篇
矿业工程   4篇
能源动力   60篇
轻工业   64篇
水利工程   5篇
石油天然气   9篇
无线电   215篇
一般工业技术   393篇
冶金工业   236篇
原子能技术   60篇
自动化技术   210篇
  2023年   18篇
  2022年   31篇
  2021年   37篇
  2020年   34篇
  2019年   30篇
  2018年   33篇
  2017年   30篇
  2016年   35篇
  2015年   23篇
  2014年   48篇
  2013年   104篇
  2012年   60篇
  2011年   92篇
  2010年   88篇
  2009年   70篇
  2008年   73篇
  2007年   63篇
  2006年   59篇
  2005年   34篇
  2004年   37篇
  2003年   41篇
  2002年   34篇
  2001年   27篇
  2000年   28篇
  1999年   21篇
  1998年   39篇
  1997年   35篇
  1996年   32篇
  1995年   32篇
  1994年   29篇
  1993年   25篇
  1992年   20篇
  1991年   29篇
  1990年   31篇
  1989年   19篇
  1988年   22篇
  1987年   21篇
  1986年   16篇
  1985年   18篇
  1984年   26篇
  1983年   20篇
  1982年   25篇
  1981年   21篇
  1980年   14篇
  1979年   17篇
  1978年   11篇
  1977年   19篇
  1976年   30篇
  1975年   6篇
  1973年   9篇
排序方式: 共有1743条查询结果,搜索用时 15 毫秒
91.
92.

The paper proposes a novel video segmentation system with maiden application of CIEDE2000 colour-difference and mean luminace pattern. CIEDE2000 colour-difference uses Lab colour space which is a stable and efficient colour space. The main advantage of Lab colour space model is that it can approximate all the available colours perceived by our human eye. CIEDE2000 colour difference is used for detecting abrupt transitions in the video. The novel contribution of the paper is the maiden use of the mean luminance pattern, increasing and decreasing patterns of the mean value of frame luminance, for detecting the gradual transition. The approach is validated on standard databases TRECVid 2001 and 2007 test video database. The performance of the proposed technique is compared with recently reported techniques and found to be superior as compared to other techniques. The accuracy achieved with the proposed method on the standard databases is 95.9% for cut transition, 78.6% for gradual transition and 92.1% overall.

  相似文献   
93.
International Journal of Control, Automation and Systems - The system of multiple agents working in coordination for a given task has several advantages on faster completion, fault-tolerance, etc....  相似文献   
94.
Evolutionary programming techniques for economic load dispatch   总被引:4,自引:0,他引:4  
Evolutionary programming has emerged as a useful optimization tool for handling nonlinear programming problems. Various modifications to the basic method have been proposed with a view to enhance speed and robustness and these have been applied successfully on some benchmark mathematical problems. But few applications have been reported on real-world problems such as economic load dispatch (ELD). The performance of evolutionary programs on ELD problems is examined and presented in this paper in two parts. In Part I, modifications to the basic technique are proposed, where adaptation is based on scaled cost. In Part II, evolutionary programs are developed with adaptation based on an empirical learning rate. Absolute, as well as relative, performance of the algorithms are investigated on ELD problems of different size and complexity having nonconvex cost curves where conventional gradient-based methods are inapplicable.  相似文献   
95.
The Journal of Supercomputing - Currently, all online social networks (OSNs) are considered to follow a power-law distribution. In this paper, the degree distribution for multiple OSNs has been...  相似文献   
96.
This paper presents a methodology for reliability-based multiobjective optimization of large-scale engineering systems. This methodology is applied to the vehicle crashworthiness design optimization for side impact, considering both structural crashworthiness and occupant safety, with structural weight and front door velocity under side impact as objectives. Uncertainty quantification is performed using two first order reliability method-based techniques: approximate moment approach and reliability index approach. Genetic algorithm-based multiobjective optimization software GDOT, developed in-house, is used to come up with an optimal pareto front in all cases. The technique employed in this study treats multiple objective functions separately without combining them in any form. It shows that the vehicle weight can be reduced significantly from the baseline design and at the same time reduce the door velocity. The obtained pareto front brings out useful inferences about optimal design regions. A decision-making criterion is subsequently invoked to select the “best” subset of solutions from the obtained nondominated pareto optimal solutions. The reliability, thus computed, is also checked with Monte Carlo simulations. The optimal solution indicated by knee point on the optimal pareto front is verified with LS-DYNA simulation results.  相似文献   
97.
The present paper deals with modeling of AC resistance of twisted litz wires used for high-frequency inverter-fed induction cooker. Several traditional approaches are available, most of which have concentrated in deriving the analytical relationships between the AC resistances with the parameters of the wire. However, it is very difficult to get the exact relationship, due to several reasons. An attempt is made in this paper to model the AC resistance using a three-layered feed-forward Neural Network. For this purpose, four inputs (wire type, number of strand, number of spiral turn and operating frequency) and one output as AC resistance have been considered. Since the performance of Neural Network alone might not be optimal; it is optimized using a binary-coded Genetic Algorithm. Performances of the proposed approach were compared with the method of AC resistance computation proposed by Ferreira. Genetic-neural system has given a very close accuracy, and the computational complexity was found to be very low. Thus, it is suitable for online implementations.  相似文献   
98.
Neural Computing and Applications - Dispersing methane to a safer level is crucial for mines safety as methane has been the greatest contributor of explosion hazard in underground coal mines...  相似文献   
99.
A new approach is proposed for determining the robust stability of discrete-time systems where each coefficient of the characteristic polynomial can take any value between specified lower and upper bounds. It is based on the use of Rouche's theorem in the theory of complex variables.  相似文献   
100.
Microsystem Technologies - In this paper synthesis of two wideband Metamaterial Cross Polarizer (MCPs) is proposed. The synthesis of proposed MCPs is done by using Binary Wind Driven Optimization...  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