全文获取类型
收费全文 | 44614篇 |
免费 | 5631篇 |
国内免费 | 3321篇 |
专业分类
电工技术 | 5597篇 |
综合类 | 4892篇 |
化学工业 | 4184篇 |
金属工艺 | 1202篇 |
机械仪表 | 2422篇 |
建筑科学 | 2830篇 |
矿业工程 | 1098篇 |
能源动力 | 1275篇 |
轻工业 | 2038篇 |
水利工程 | 975篇 |
石油天然气 | 1885篇 |
武器工业 | 680篇 |
无线电 | 5871篇 |
一般工业技术 | 4144篇 |
冶金工业 | 1708篇 |
原子能技术 | 625篇 |
自动化技术 | 12140篇 |
出版年
2024年 | 159篇 |
2023年 | 521篇 |
2022年 | 1032篇 |
2021年 | 1227篇 |
2020年 | 1513篇 |
2019年 | 1446篇 |
2018年 | 1244篇 |
2017年 | 1697篇 |
2016年 | 1879篇 |
2015年 | 1989篇 |
2014年 | 2704篇 |
2013年 | 3113篇 |
2012年 | 3195篇 |
2011年 | 3390篇 |
2010年 | 2514篇 |
2009年 | 2663篇 |
2008年 | 2543篇 |
2007年 | 3031篇 |
2006年 | 2756篇 |
2005年 | 2290篇 |
2004年 | 1893篇 |
2003年 | 1754篇 |
2002年 | 1531篇 |
2001年 | 1313篇 |
2000年 | 1144篇 |
1999年 | 903篇 |
1998年 | 724篇 |
1997年 | 622篇 |
1996年 | 482篇 |
1995年 | 414篇 |
1994年 | 334篇 |
1993年 | 279篇 |
1992年 | 190篇 |
1991年 | 184篇 |
1990年 | 128篇 |
1989年 | 126篇 |
1988年 | 85篇 |
1987年 | 86篇 |
1986年 | 58篇 |
1985年 | 58篇 |
1984年 | 46篇 |
1983年 | 38篇 |
1982年 | 37篇 |
1981年 | 29篇 |
1980年 | 29篇 |
1979年 | 25篇 |
1978年 | 13篇 |
1977年 | 13篇 |
1964年 | 12篇 |
1955年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
针对注射过程具有重复运行和非线性的特性,在对预测控制与迭代学习控制进行综合应用并加以改进的基础上,给出一种模型预测迭代学习复合控制新算法,研究了控制器的设计方案.同时,将迭代学习思想引入到预测步长的在线调整,提出了预测步长的迭代学习方法.仿真结果表明,该方法是有效的,其控制性能优于PID迭代学习控制系统. 相似文献
992.
大时滞系统时间协调参数调整控制策略 总被引:1,自引:0,他引:1
针对大时滞系统难以实现闭环稳定控制的问题,引入脉冲响应等效系统的概念,提出时间协调参数修改控制算法.该算法由两部分组成.一是通过时间协调原则修改控制器的输出;二是利用脉冲响应等效系统来修改控制器的参数,使脉冲响应等效系统和大时滞系统匹配,跟踪被控制对象参数变化产生自适应性,保证控制系统精度和稳定性.并用于氧化铝生产过程碳酸化分解工序,将原来手动操作开环控制改为闭环控制,提高了分解率和产品的合格率.该控制算法是递推算法,计算量小,便于在线实现. 相似文献
993.
在网络化控制系统(Networked Control Systems,简记为NCSs)中,由于网络的介入使控制系统的规模和复杂性显著增加,且产生了各种新问题,为了使控制更加容易,需要设计合理的估计策略.主要从控制和通信2个角度出发,集中考虑了在量化影响、时延与丢包、不确定性等通信受限因素下状态估计策略的研究与进展.一直以来,状态估计都是诸如过程监控、故障诊断等控制领域中不可缺少的重要部分,当前已成为网络化控制系统研究的热点和准点,为抵消网络环境不确定性对闭环系统性能的影响,设计最优的状态估计策略必将成为不可缺少的因素之一. 相似文献
994.
995.
This paper focuses on H∞ filtering for linear time‐delay systems. A new Lyapunov–Krasovskii functional (LKF) is constructed by uniformly dividing the delay interval into two subintervals, and choosing different Lyapunov matrices on each subinterval. Based on this new LKF, a less conservative delay‐dependent bounded real lemma (BRL) is established to ensure that the resulting filtering error system is asymptotically stable with a prescribed H∞ performance. Then, this new BRL is equivalently converted into a set of linear matrix inequalities, which guarantee the existence of a suitable H∞ filter. Compared with some existing filtering results, some imposed constraints on the Lyapunov matrices are removed through derivation of the sufficient condition for the existence of the filter. Numerical examples show that the results obtained in this paper significantly improve the H∞ performance of the filtering error system over some existing results in the literature. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
996.
The problem-solving time and the solution accuracy are expressed as functions of a parameter. An optimization problem of choosing
the parameter using a “time cost–solution accuracy” criterion is considered. A Pareto-optimal set of solutions is obtained.
The best value of the parameter is chosen by the ideal-point method.
Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 98–105, July–August 2009. 相似文献
997.
This paper investigates the problem of output feedback stabilization for a class of uncertain linear systems with faulty actuators via the synergy with a switching strategy. When actuators suffer a ‘destabilizing failure’ and the never‐faulty actuators cannot stabilize the given system, the closed‐loop exponential stability can still be achieved via the average dwell‐time scheme employing an arbitrary switching signal. The prerequisite condition found requires the ratio between the two lapse times, when the system is devoid of faulty actuators and when it is not so, to be less than a certain specified constant. Then the stabilizing output feedback controls are designed via the technique of linear matrix inequalities. The illustrative example and the respective simulation results demonstrate the feasibility and effectiveness of the proposed design synthesis. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
998.
The robust stochastic stability, stabilization and H∞ control for mode‐dependent time‐delay discrete Markovian jump singular systems with parameter uncertainties are discussed. Based on the restricted system equivalent (r.s.e.) transformation and by introducing new state vectors, the singular system is transformed into a standard linear system, and delay‐dependent linear matrix inequalities (LMIs) conditions for the mode‐dependent time‐delay discrete Markovian jump singular systems to be regular, causal and stochastically stable, and stochastically stable with γ‐disturbance attenuation are obtained, respectively. With these conditions, robust stabilization problem and robust H∞ control problem are solved, and the LMIs sufficient conditions are obtained. A numerical example illustrates the effectiveness of the method given in the paper. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
999.
A stability robustness test is developed for internally stable, nominal, linear time‐invariant (LTI) feedback systems subject to structured, linear time‐varying uncertainty. There exists (in the literature) a necessary and sufficient structured small gain condition that determines robust stability in such cases. In this paper, the structured small gain theorem is utilized to formulate a (sufficient) stability robustness condition in a scaled LTI ν‐gap metric framework. The scaled LTI ν‐gap metric stability condition is shown to be computable via linear matrix inequality techniques, similar to the structured small gain condition. Apart from a comparison with a generalized robust stability margin as the final part of the stability test, however, the solution algorithm implemented to test the scaled LTI ν‐gap metric stability robustness condition is shown to be independent of knowledge about the controller transfer function (as opposed to the LMI feasibility problem associated with the scaled small gain condition which is dependent on knowledge about the controller). Thus, given a nominal plant and a structured uncertainty set, the stability robustness condition presented in this paper provides a single constraint on a controller (in terms of a large enough generalized robust stability margin) that (sufficiently) guarantees to stabilize all plants in the uncertainty set. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
1000.
HyungKi Hong JaeKyeong Yoon Moojong Lim 《Journal of the Society for Information Display》2009,17(7):567-572
Abstract— The dynamic performance of displays is an important characteristic for multimedia applications. Motion‐picture response time (MPRT) has been used as an indicator of the dynamic performance of LCDs. This paper describes a comprehensive method of MPRT evaluation for the oblique viewing direction. By using a tilted camera configuration, the angular dependency of MPRT is investigated for the condition that the horizontally scrolling patterns are observed from the vertical direction. For each gray‐to‐gray transition, distinct changes in MPRT and the luminance profile of blur are observed. 相似文献