全文获取类型
收费全文 | 2693篇 |
免费 | 573篇 |
国内免费 | 606篇 |
专业分类
电工技术 | 462篇 |
综合类 | 468篇 |
化学工业 | 91篇 |
金属工艺 | 23篇 |
机械仪表 | 169篇 |
建筑科学 | 72篇 |
矿业工程 | 20篇 |
能源动力 | 48篇 |
轻工业 | 33篇 |
水利工程 | 10篇 |
石油天然气 | 10篇 |
武器工业 | 86篇 |
无线电 | 341篇 |
一般工业技术 | 236篇 |
冶金工业 | 15篇 |
原子能技术 | 10篇 |
自动化技术 | 1778篇 |
出版年
2024年 | 17篇 |
2023年 | 63篇 |
2022年 | 81篇 |
2021年 | 95篇 |
2020年 | 119篇 |
2019年 | 111篇 |
2018年 | 89篇 |
2017年 | 116篇 |
2016年 | 136篇 |
2015年 | 148篇 |
2014年 | 200篇 |
2013年 | 213篇 |
2012年 | 216篇 |
2011年 | 225篇 |
2010年 | 200篇 |
2009年 | 191篇 |
2008年 | 185篇 |
2007年 | 207篇 |
2006年 | 180篇 |
2005年 | 146篇 |
2004年 | 145篇 |
2003年 | 104篇 |
2002年 | 94篇 |
2001年 | 90篇 |
2000年 | 70篇 |
1999年 | 55篇 |
1998年 | 46篇 |
1997年 | 41篇 |
1996年 | 43篇 |
1995年 | 40篇 |
1994年 | 38篇 |
1993年 | 33篇 |
1992年 | 30篇 |
1991年 | 30篇 |
1990年 | 31篇 |
1989年 | 14篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1984年 | 8篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1955年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有3872条查询结果,搜索用时 31 毫秒
1.
将强跟踪思想引入容积卡尔曼滤波(cubature Kalman filter,CKF),建立强跟踪CKF能有效克服CKF在模型不确定、状态突变等情况下,滤波性能下降的问题。通过分析现有多渐消因子计算方法,发现它们均只利用了协方差矩阵的对角线元素,并没有考虑各个状态之间的相关性,不能充分发挥多渐消因子的优势。为此,本文提出渐消因子矩阵,基于正交原理推导渐消因子矩阵的求解方法,提出多渐消因子强跟踪CKF算法。多渐消因子强跟踪CKF算法突破了传统多渐消因子为向量的限制,也不再要求渐消因子取值要大于1。仿真验证了算法具有更好的滤波精度何鲁棒性,能更好的满足工程应用的要求。 相似文献
2.
Liyan Wen Gang Tao Bin Jiang 《International Journal of Adaptive Control and Signal Processing》2021,35(3):373-400
In this article, adaptive compensation designs are developed for nonlinear systems with uncertainties from the system functions and persistent actuator failures of characterizations that (i) some unknown system inputs are stuck at some unknown fixed or varying values at unknown time instants and (ii) the failure pattern always switches from one to another and the switching does not stop. Such a controlled plant is described by an uncertain time-varying nonlinear system, and some robust adaptive feedback linearization based failure compensation results are studied for closed-loop system stabilization and bounded output tracking for some specific conditions. To improve the tracking performance in the presence of persistent actuator failures, a new adaptive control scheme is developed, using the failure indicator function which contains the failure pattern and failure time in the formulation. Detailed stability and tracking performance are shown. Simulation results are shown to verify the effectiveness of the proposed adaptive actuator failure compensation method. 相似文献
3.
Biological information is stored in DNA, RNA and protein sequences, which can be understood as genotypes that are translated into phenotypes. The properties of genotype–phenotype (GP) maps have been studied in great detail for RNA secondary structure. These include a highly biased distribution of genotypes per phenotype, negative correlation of genotypic robustness and evolvability, positive correlation of phenotypic robustness and evolvability, shape-space covering, and a roughly logarithmic scaling of phenotypic robustness with phenotypic frequency. More recently similar properties have been discovered in other GP maps, suggesting that they may be fundamental to biological GP maps, in general, rather than specific to the RNA secondary structure map. Here we propose that the above properties arise from the fundamental organization of biological information into ‘constrained'' and ‘unconstrained'' sequences, in the broadest possible sense. As ‘constrained'' we describe sequences that affect the phenotype more immediately, and are therefore more sensitive to mutations, such as, e.g. protein-coding DNA or the stems in RNA secondary structure. ‘Unconstrained'' sequences, on the other hand, can mutate more freely without affecting the phenotype, such as, e.g. intronic or intergenic DNA or the loops in RNA secondary structure. To test our hypothesis we consider a highly simplified GP map that has genotypes with ‘coding'' and ‘non-coding'' parts. We term this the Fibonacci GP map, as it is equivalent to the Fibonacci code in information theory. Despite its simplicity the Fibonacci GP map exhibits all the above properties of much more complex and biologically realistic GP maps. These properties are therefore likely to be fundamental to many biological GP maps. 相似文献
4.
5.
工业过程随机稳态优化控制算法的鲁棒性分析 总被引:1,自引:0,他引:1
本文给出了一种随机稳态优化算法的灵敏度分析,讨论算法解对参数变化的关系。这些参数代表系统结构参数或噪声向量的某些数字特征. 相似文献
6.
7.
广义系统一类鲁棒观测器的设计 总被引:3,自引:0,他引:3
本文讨论了用观测器消除广义系统中由于模型误差、非线性因素、参数不确定及输入输
出噪声产生的量测误差的可能性,给出了这类鲁棒观测器的存在条件,得到了相应的算法. 相似文献
8.
On the learning control of a robot manipulator 总被引:1,自引:0,他引:1
D. M. Dawson Z. Qu J. F. Dorsey F. L. Lewis 《Journal of Intelligent and Robotic Systems》1991,4(1):43-53
This paper derives a learning control law to achieve trajectory following for a robot manipulator. The controller consists of two parts, a computed torque servo for the rigid body terms that can be modelled and a learning law for the unmodelled dynamics. An advantage of this method is that bounds can be assigned to the position and velocity tracking errors. 相似文献
9.
Shawn Hu Author Vitae Author Vitae 《Automatica》2007,43(7):1243-1248
This paper is concerned with stability analysis of discrete-time networked control systems over a communication channel subject to packet loss whose behavior is modeled by an i.i.d Bernoulli process with a packet dropping probability bounded by a constant. A necessary and sufficient condition for stability is obtained. A packet dropping margin is introduced as a measure of stability robustness of a system against packet dropping, and a formula for it is derived. A design method is proposed for achieving a large margin subject to a constraint that the system has a set of prescribed nominal closed-loop poles. 相似文献
10.