全文获取类型
收费全文 | 1961篇 |
免费 | 216篇 |
国内免费 | 104篇 |
专业分类
电工技术 | 78篇 |
综合类 | 99篇 |
化学工业 | 117篇 |
金属工艺 | 46篇 |
机械仪表 | 221篇 |
建筑科学 | 51篇 |
矿业工程 | 24篇 |
能源动力 | 41篇 |
轻工业 | 195篇 |
水利工程 | 9篇 |
石油天然气 | 77篇 |
武器工业 | 19篇 |
无线电 | 159篇 |
一般工业技术 | 93篇 |
冶金工业 | 46篇 |
原子能技术 | 18篇 |
自动化技术 | 988篇 |
出版年
2024年 | 3篇 |
2023年 | 16篇 |
2022年 | 20篇 |
2021年 | 27篇 |
2020年 | 31篇 |
2019年 | 28篇 |
2018年 | 39篇 |
2017年 | 53篇 |
2016年 | 37篇 |
2015年 | 57篇 |
2014年 | 132篇 |
2013年 | 122篇 |
2012年 | 167篇 |
2011年 | 163篇 |
2010年 | 123篇 |
2009年 | 115篇 |
2008年 | 134篇 |
2007年 | 142篇 |
2006年 | 131篇 |
2005年 | 82篇 |
2004年 | 78篇 |
2003年 | 92篇 |
2002年 | 67篇 |
2001年 | 54篇 |
2000年 | 33篇 |
1999年 | 40篇 |
1998年 | 26篇 |
1997年 | 28篇 |
1996年 | 28篇 |
1995年 | 33篇 |
1994年 | 23篇 |
1993年 | 22篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 13篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 5篇 |
排序方式: 共有2281条查询结果,搜索用时 31 毫秒
21.
22.
23.
Doe Gyoon Koo Ho Cheol Park Jin Young Choi Jietae Lee 《Chemical Engineering Communications》2004,191(5):611-624
Each controller in multiloop control systems for multivariable processes can be tuned sequentially with the ultimate information for the paired input and output while former loops have been closed, and hence, single-input single-output autotuning methods can be applied. In this sequential autotuning for multiloop control systems, several iterations are usually required for better control performances. Especially when pairings are undesirable, the autotuning sequences should be repeated with correct pairings, which result in long field experiments. Here, to avoid this drawback, a simple method to identify process models while loops are being sequentially tuned is proposed. The identified models can be used to correct pairings of multiloop control systems and to improve tuning performances without several field iterations. In addition, they can be used to obtain model-based control systems such as decoupling control systems. 相似文献
24.
Traditional methods based on the product of exponentials (POE) formula are parametrically continuous and complete for the calibration of the kinematic parameters of serial robots. However, these methods are not minimal due to the constraints of joint twists. This paper puts forward a new POE-based model, whose parameters are totally independent and conform to the formula of minimality. This is the first model that simultaneously satisfies the requirements of parametric continuity, completeness, and minimality with uniform and generic modeling rules. The proposed approach avoids the operations of normalization and orthogonalization which are necessary redundancy elimination steps with the traditional model. Simulations on a SCARA robot and experiments on an ABB IRB 120 robot prove that the new model outperforms in convergence, accuracy, and efficiency. 相似文献
25.
本文基于系统辨识的最小二乘法,介绍一种用Basic语言编程的SISO线性系统系统辨识软件包及其原理、结构、功能与特点。它包括输入/输出数据的生成,近十种辨识程序模块的调用,结果的处理,模型阶次与纯滞后时间的确定和模型校验等五大部分。经应用已证明设计合理,方便可靠,并具有结构简单灵活等特点。 相似文献
26.
基于先验知识的自适应多叉树防碰撞算法 总被引:1,自引:0,他引:1
为提高无线射频识别(RFID)系统快速识别大量标签的能力,提出一种基于先验知识的自适应多叉树防碰撞算法。利用标签访问的规律性和标签分布的随机性,在不同的搜索深度,根据已有的先验知识和碰撞比特信息估计待识别的标签数量,从而动态地自适应选择搜索叉树。通过有效减少碰撞和空闲时隙数,大幅提高读写器搜索和识别标签的能力。理论分析与仿真实验结果表明,该算法能克服传统自适应多叉树防碰撞算法的缺点,合理选择初始搜索叉树,尤其在待识别标签数量较多的场合,可有效提高RFID系统的吞吐率。 相似文献
27.
针对射频识别(RFID)认证协议安全性较差的问题,设计一个基于动态ID带搜索密钥的RFID认证协议。标签利用单向hash函数的部分输出更新搜索密钥和ID。分析表明,该协议能够有效地实现标签与阅读器之间的相互认证,同时能够抵抗包含前向安全、后向安全、位置跟踪在内的多种攻击,而且硬件需求不高,适合低成本标签使用。 相似文献
28.
29.
In order to demonstrate the effectiveness of the process identification algorithm, on-line parameter estimator is evaluated
experimentally by using two-tank system with interaction. On-line parameter estimator used in this paper is based on a recursive
parameter estimation algorithm. MIMO linear, bilinear and quadratic models based on ARMA model are used to identify two-tank
system. A quadratic model for two-tank system with interaction is developed to confirm the propriety of MIMO quadratic model
used in identification of two-tank system. The results of on-line identification experiments on the two-tank system show that
the estimated parameters of each model converge and the output tracking errors are bounded by disturbance bound. But, the
quadratic model showed the best convergence. 相似文献
30.
The paper presents a theoretical analysis of stresses generated during convective drying of kaolin, based on elastic and viscoelastic models. The equations of these models were solved analytically for a cylindrically shaped sample; the distribution and evolution of the radial and circumferential stresses are illustrated in diagrams. The acoustic emission method was used in experimental tests for identification on line of the time period during which the stresses reach their maximal values. A better correlation has been found between the experimental tests and the theoretical predictions obtained on the basis of the viscoelastic model. 相似文献