全文获取类型
收费全文 | 16353篇 |
免费 | 2136篇 |
国内免费 | 1449篇 |
专业分类
电工技术 | 766篇 |
综合类 | 2142篇 |
化学工业 | 560篇 |
金属工艺 | 1197篇 |
机械仪表 | 3575篇 |
建筑科学 | 412篇 |
矿业工程 | 481篇 |
能源动力 | 136篇 |
轻工业 | 184篇 |
水利工程 | 146篇 |
石油天然气 | 145篇 |
武器工业 | 304篇 |
无线电 | 1356篇 |
一般工业技术 | 1219篇 |
冶金工业 | 159篇 |
原子能技术 | 45篇 |
自动化技术 | 7111篇 |
出版年
2024年 | 110篇 |
2023年 | 370篇 |
2022年 | 601篇 |
2021年 | 656篇 |
2020年 | 668篇 |
2019年 | 522篇 |
2018年 | 584篇 |
2017年 | 613篇 |
2016年 | 649篇 |
2015年 | 764篇 |
2014年 | 971篇 |
2013年 | 1010篇 |
2012年 | 1084篇 |
2011年 | 1154篇 |
2010年 | 912篇 |
2009年 | 1004篇 |
2008年 | 949篇 |
2007年 | 1254篇 |
2006年 | 1019篇 |
2005年 | 930篇 |
2004年 | 755篇 |
2003年 | 660篇 |
2002年 | 455篇 |
2001年 | 456篇 |
2000年 | 327篇 |
1999年 | 228篇 |
1998年 | 191篇 |
1997年 | 192篇 |
1996年 | 127篇 |
1995年 | 117篇 |
1994年 | 129篇 |
1993年 | 90篇 |
1992年 | 93篇 |
1991年 | 74篇 |
1990年 | 64篇 |
1989年 | 59篇 |
1988年 | 49篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1976年 | 2篇 |
1964年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
93.
This paper presents a novel scheme for visual servoing of a nonholonomic mobile robot equipped with a monocular camera
in consideration of field-of-view (FOV) constraints. In order to loosen the FOV constraints, the system states are expressed by the
homography between the current frame and the key frame so that the target is not necessarily to be always visible in the control
process. A switched visual controller is designed to deal with the nonholonomic constraints. Moreover, an iteration strategy is
used to eliminate errors caused by the parameter uncertainty. The stablity and robustness of the proposed scheme are guaranteed
by theoretical analysis. Compared to conventional schemes, the proposed approach has the following advantages: 1) a better path
in Cartesian space can be achieved owing to the loosening of FOV constraints; 2) the iteration strategy ensures the robustness
to parameter uncertainty; 3) when used in landmark-based navigation, it needs much sparser and simpler landmarks than those
localization-based approaches need. Simulation results demonstrate the effectiveness of the proposed method. 相似文献
94.
Joe Miseli 《Journal of the Society for Information Display》2013,21(6):214-224
On June 1, 2012, the Information Display Measurement Standard version 1 was released. This is the first standard from the worldwide standard group, the International Committee for Display Metrology, a standards committee within SID, and it culminates several years worth of development from many contributors at various levels. It has 26 top‐level chapters and a total over 450 sections of all parts, including over 200 measurement sections and 8 appendices that cover 133 topics of display metrology, tutorials, technical discussions, and references. Herein is an overview of the Information Display Measurement Standard version 1, including the structure of the document, tips, tricks, and hidden features, how it is maintained, support material, a breakdown of its contents, and finally, a sampling of four of the over 200 measurements. The standard is available as a free download and can be found on the International Committee for Display Metrology home page — http://www.icdm‐sid.org . 相似文献
95.
Discrete linear quadratic control has been efciently applied to linear systems as an optimal control.However,a robotic system is highly nonlinear,heavily coupled and uncertain.To overcome the problem,the robotic system can be modeled as a linear discrete-time time-varying system in performing repetitive tasks.This modeling motivates us to develop an optimal repetitive control.The contribution of this paper is twofold.For the frst time,it presents discrete linear quadratic repetitive control for electrically driven robots using the mentioned model.The proposed control approach is based on the voltage control strategy.Second,uncertainty is efectively compensated by employing a robust time-delay controller.The uncertainty can include parametric uncertainty,unmodeled dynamics and external disturbances.To highlight its ability in overcoming the uncertainty,the dynamic equation of an articulated robot is introduced and used for the simulation,modeling and control purposes.Stability analysis verifes the proposed control approach and simulation results show its efectiveness. 相似文献
96.
水轮机调速器是水电站重要的自动化设备,其质量的好坏直接影响到电能品质和水电站安全及经济运行.文章主要从小浪底和西霞院及西沟水电站调速器的选用来分析其各自调速器的异同及特点. 相似文献
97.
为了更好地与复杂多变的非结构化环境进行交互,完成对目标物体的识别和抓取,提出了一种应用于服务机器人平台的基于双目视觉的仿人机械臂控制方法.文中首先用D-H方法对机械臂进行建模,并对这个模型做了改进,给出了一种更加简便的3+1自由度仿人机械臂的逆解算法,采用基于双目视觉与颜色分割的目标识别方法;然后根据识别出的目标三维坐标信息控制机械臂完成抓取任务;最后,本方法在家庭服务机器人上得到了验证,机器人能够完成对目标物体的识别和抓取动作. 相似文献
98.
针对动态背景下运动目标检测的问题,最大限度地降低背景对运动目标检测的影响,提出了一种基于相位相关法和傅里叶梅林变换的动态背景下运动目标检测算法.动态背景下运动目标检测的主要部分是背景运动补偿,首先利用相位相关法和傅里叶梅林变换估计全局运动参量,然后根据全局运动参量利用双线性内插法进行背景匹配,最后对配准后的图像利用帧间差分法提取运动目标.实验表明,该算法具有一定的鲁棒性,能有效地检测动态背景下的运动目标. 相似文献
99.
为了提高足球机器人中策略执行的有效性和针对性,提出了一种基于赛场正向态势评估和反向执行效果评估的有限状态自动机分层决策模型。该模型将赛场决策分为战术策略和具体任务,通过正向态势评估信息和任务执行效果的反馈信息进行综合量化,基于有限状态自动机建立策略和任务的转换关系,从而做出适合当前态势的战术策略。经仿真实验表明,该决策模型在很大程度上提高了策略决策的有效性和针对性,使得球队的整体攻防能力得到了相应的改善。 相似文献
100.
The method of artificial potential field has obvious advantages among the robot path planning methods including simple structure, small amount of calculation and relatively mature in theory. This paper puts forward the "Integral method" focusing on solving the problem of local minimization. The method analyses the distribution of obstructions in a given environment and regards adjacent obstacles as a whole, By changing the parameters of the repulsive force field, robots can quickly get out of the minimum point and move to the target point. This paper uses the Simurosot platform to carry on the simulation experiment on the improved artificial potential field method, which projects a feasible path successfully and verifies this method. 相似文献