全文获取类型
收费全文 | 22426篇 |
免费 | 3751篇 |
国内免费 | 3109篇 |
专业分类
电工技术 | 3558篇 |
综合类 | 2610篇 |
化学工业 | 688篇 |
金属工艺 | 1394篇 |
机械仪表 | 1657篇 |
建筑科学 | 452篇 |
矿业工程 | 329篇 |
能源动力 | 288篇 |
轻工业 | 417篇 |
水利工程 | 233篇 |
石油天然气 | 368篇 |
武器工业 | 420篇 |
无线电 | 4302篇 |
一般工业技术 | 1560篇 |
冶金工业 | 1651篇 |
原子能技术 | 55篇 |
自动化技术 | 9304篇 |
出版年
2024年 | 199篇 |
2023年 | 532篇 |
2022年 | 719篇 |
2021年 | 761篇 |
2020年 | 980篇 |
2019年 | 889篇 |
2018年 | 832篇 |
2017年 | 967篇 |
2016年 | 1018篇 |
2015年 | 1135篇 |
2014年 | 1555篇 |
2013年 | 1699篇 |
2012年 | 1855篇 |
2011年 | 1945篇 |
2010年 | 1482篇 |
2009年 | 1456篇 |
2008年 | 1445篇 |
2007年 | 1567篇 |
2006年 | 1407篇 |
2005年 | 1151篇 |
2004年 | 928篇 |
2003年 | 820篇 |
2002年 | 652篇 |
2001年 | 568篇 |
2000年 | 499篇 |
1999年 | 395篇 |
1998年 | 340篇 |
1997年 | 274篇 |
1996年 | 252篇 |
1995年 | 198篇 |
1994年 | 145篇 |
1993年 | 138篇 |
1992年 | 129篇 |
1991年 | 84篇 |
1990年 | 70篇 |
1989年 | 51篇 |
1988年 | 43篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 18篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1960年 | 3篇 |
1958年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
An analysis is made of the characteristic features and problems of the optimal processing of the results of measurements in the case of a random observation function utilizing a nonlinear Kalman filter. A method is proposed for increasing the convergence domain of the filter with additional processing of measurements in the frequency domain. 相似文献
2.
系统备份及其误区分析 总被引:1,自引:0,他引:1
张军华 《微电子学与计算机》2002,19(9):34-35
文章对系统备份的几个主要方面进行了讨论,并在此基础上,对系统备分的若干认识误区进行了分析。 相似文献
3.
Xuejun Xie Siying Zhang 《International Journal of Adaptive Control and Signal Processing》2002,16(1):39-59
This paper considers the adaptive pole‐placement control problem for system (1) with unmodelled dynamics ηn dominated by a small constant ε multiplied by a quantity independent of ε but tending to infinity as the past input, output, and noise grow. Using bounded external excitation and randomly varying truncation techniques, we give a design method of adaptive pole‐placement controller. It is shown that the closed‐loop system is globally stable, the estimation error for the parameter contained in the modelled part is of order ε, and the closed‐loop system under the adaptive pole‐placement control law is suboptimal in the sense of $$\mathop{\lim\sup}\limits_{{n\to\infty }}{1\over n}\mathop{\sum}\limits_{i=0}^n{\left({A^{*}(z)y_{n}‐L(z)C(z)w_{n}‐B(z)R(z)y_{n}^{*}}\right)^{2}{\leq}O({\varepsilon}^{2})+\gamma^{2}\mathop{\sum}\limits_{j=1}^q{b_{j}^{2}}}$$\nopagenumbers\end while the SPR condition used usually in other papers is replaced by a stability condition. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
4.
Ahmadreza Momeni Amir G. Aghdam 《International Journal of Adaptive Control and Signal Processing》2007,21(10):885-910
Most of the existing switching control techniques are developed specifically for finite-dimensional linear time-invariant (LTI) systems. In many practical applications, however, it is essential to take time delay into consideration in the modelling as the control system can be highly sensitive to delay. In this paper, a multi-model switching control algorithm is proposed for retarded time-delay systems. It is assumed that the plant is represented by a family of known multi-input multi-output, observable, LTI models with multiple delays in the states, and that corresponding to each model in the known family, there exists a high-performance finite-dimensional LTI controller. In addition, it is supposed that a bound on the magnitude of the external inputs and disturbances is available. It is then shown that the proposed switching controller can stabilize the uncertain system, and that under some mild conditions, output tracking can be achieved in the given problem setting. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
5.
6.
G. Bartolini A. Ferrara 《International Journal of Adaptive Control and Signal Processing》1992,6(3):237-246
In this paper we pursue a twofold aim. First we want to simplify the complexity of the classical Monopoli's scheme, the so-called ‘Augmented error signal control scheme’. Then we also wish to cope with the realistic situation in which the presence of unmodelled dynamics has to be taken into account. This latter problem has been faced in the literature by suitably modifying the adaptation mechanism in order to avoid undesired phenomena as well as to obtain an attractive stability region for the state trajectories starting from any point in a predefined initial condition set. In our case the necessity of introducing any sort of modification in the adaptation mechanism is completely avoided, but we still obtain asymptotic stability of the output error signal. 相似文献
7.
本钢1700连轧机应用的托辊原由外企业制作,为了减少公司资金外流,公司技术人员和工人结合现有的生产条件,先后攻克了辊身铸造和加工,托辊装配等工艺方面的难关,研制成功了合格的产品,年创经济效益80万元。 相似文献
8.
9.
High speedsteel (HSS) ,ischaracterizedbyex cellenthardness ,wearresistance ,and goodredhardness .Recently ,HSSisappliedtomanufacturehotrollingrollstoproducestripsofgoodshapeandsmallcrownwithextendedrollservicelife[1,2 ] .TheHSSisappliedtomanufacturerollcollarfor… 相似文献
10.
磨料高压水除鳞系统设计研究 总被引:1,自引:0,他引:1
磨料高压水除鳞系统取代酸洗线,原机械部分和磨料高压水部分都作了较大改进,才能保证除鳞彻底。 相似文献