全文获取类型
收费全文 | 3815篇 |
免费 | 789篇 |
国内免费 | 660篇 |
专业分类
电工技术 | 1229篇 |
综合类 | 450篇 |
化学工业 | 101篇 |
金属工艺 | 91篇 |
机械仪表 | 330篇 |
建筑科学 | 196篇 |
矿业工程 | 136篇 |
能源动力 | 111篇 |
轻工业 | 26篇 |
水利工程 | 140篇 |
石油天然气 | 59篇 |
武器工业 | 145篇 |
无线电 | 426篇 |
一般工业技术 | 156篇 |
冶金工业 | 97篇 |
原子能技术 | 35篇 |
自动化技术 | 1536篇 |
出版年
2024年 | 65篇 |
2023年 | 154篇 |
2022年 | 210篇 |
2021年 | 238篇 |
2020年 | 261篇 |
2019年 | 231篇 |
2018年 | 232篇 |
2017年 | 281篇 |
2016年 | 272篇 |
2015年 | 230篇 |
2014年 | 302篇 |
2013年 | 279篇 |
2012年 | 296篇 |
2011年 | 291篇 |
2010年 | 203篇 |
2009年 | 210篇 |
2008年 | 172篇 |
2007年 | 229篇 |
2006年 | 187篇 |
2005年 | 132篇 |
2004年 | 132篇 |
2003年 | 105篇 |
2002年 | 95篇 |
2001年 | 89篇 |
2000年 | 76篇 |
1999年 | 44篇 |
1998年 | 32篇 |
1997年 | 42篇 |
1996年 | 41篇 |
1995年 | 30篇 |
1994年 | 22篇 |
1993年 | 17篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 11篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有5264条查询结果,搜索用时 15 毫秒
101.
102.
In this paper, the design of the two-degree-of-freedom optimal Wiener–Hopf controller with asymptotic tracking and disturbance rejection constraints is studied. Based on the solvability conditions and the solution parameterization of Diophantine equations over the stable rational fractional ring M(s), the disturbance rejection problem in the general case is solved. A simple cost function is defined to reflect the transient performance of control signal caused by deterministic signals. Finally, the design of the two-degree-of-freedom optimal Wiener–Hopf controller is presented. 相似文献
103.
104.
重复控制系统中非周期扰动的抑制 总被引:3,自引:0,他引:3
为了改善重复控制系统中的扰动抑制性能,提出一种基于曲率模型的扰动估计新方法.该方法的主要特点是扰动的估计值直接与重复控制规则结合也不影响重复控制系统的稳定性.仿真结果显示该方法可以有效地抑制扰动. 相似文献
105.
106.
107.
The H∞ almost disturbance decoupling problem is considered. In this paper, a nonlinear design is proposed to find a state feedback controller for bilinear systems. The closed‐loop system is internally stable and achieves disturbance attenuation in nonlinear H∞ sense. We defined a special form of Lyapunov function, which is constructed in terms of one or a set of positive definite constant matrices. If, except of the origin of system, the corresponding polynomial of the positive definite matrix (or several polynomials relevant to the positive definite constant matrices) has (have) no zero on a given subset of state space, then we can construct a controller to solve our problem. It is found that the controller structure could be complicated, but is feasible in computation and may require optimization technique to search the solution. We consider both SIMO and MIMO cases with illustrated examples. 相似文献
108.
109.
110.
The quality of the micro-mechanical machining outcome depends significantly on the tracking performance of the miniaturized
linear motor drive precision stage. The tracking behavior of a direct drive design is prone to uncertainties such as model
parameter variations and disturbances. Robust optimal tracking controller design for this kind of precision stages with mass
and damping ratio uncertainties was researched. The mass and damping ratio uncertainties were modeled as the structured parametric
uncertainty model. An identification method for obtaining the parametric uncertainties was developed by using unbiased least
square technique. The instantaneous frequency bandwidth of the external disturbance signals was analyzed by using short time
Fourier transform technique. A two loop tracking control strategy that combines the μ-synthesis and the disturbance observer
(DOB) techniques was proposed. The μ-synthesis technique was used to design robust optimal controllers based on structured
uncertainty models. By complementing the μ controller, the DOB was applied to further improving the disturbance rejection
performance. To evaluate the positioning performance of the proposed control strategy, the comparative experiments were conducted
on a prototype micro milling machine among four control schemes: the proposed two-loop tracking control, the single loop μ
control, the PID control and the PID with DOB control. The disturbance rejection performances, the root mean square (RMS)
tracking errors and the performance robustness of different control schemes were studied. The results reveal that the proposed
control scheme has the best positioning performance. It reduces the maximal errors caused by disturbance forces such as friction
force by 60% and the RMS errors by 63.4% compared with the PID control. Compared to PID with DOB control, it reduces the RMS
errors by 29.6%. 相似文献