全文获取类型
| 收费全文 | 4855篇 |
| 免费 | 882篇 |
| 国内免费 | 233篇 |
专业分类
| 电工技术 | 235篇 |
| 综合类 | 625篇 |
| 化学工业 | 11篇 |
| 金属工艺 | 29篇 |
| 机械仪表 | 366篇 |
| 建筑科学 | 52篇 |
| 矿业工程 | 70篇 |
| 能源动力 | 27篇 |
| 轻工业 | 10篇 |
| 水利工程 | 310篇 |
| 石油天然气 | 27篇 |
| 武器工业 | 555篇 |
| 无线电 | 1089篇 |
| 一般工业技术 | 235篇 |
| 冶金工业 | 76篇 |
| 原子能技术 | 7篇 |
| 自动化技术 | 2246篇 |
出版年
| 2025年 | 49篇 |
| 2024年 | 104篇 |
| 2023年 | 147篇 |
| 2022年 | 146篇 |
| 2021年 | 156篇 |
| 2020年 | 183篇 |
| 2019年 | 158篇 |
| 2018年 | 179篇 |
| 2017年 | 188篇 |
| 2016年 | 228篇 |
| 2015年 | 270篇 |
| 2014年 | 376篇 |
| 2013年 | 321篇 |
| 2012年 | 369篇 |
| 2011年 | 421篇 |
| 2010年 | 301篇 |
| 2009年 | 306篇 |
| 2008年 | 311篇 |
| 2007年 | 385篇 |
| 2006年 | 285篇 |
| 2005年 | 200篇 |
| 2004年 | 156篇 |
| 2003年 | 149篇 |
| 2002年 | 106篇 |
| 2001年 | 95篇 |
| 2000年 | 77篇 |
| 1999年 | 53篇 |
| 1998年 | 51篇 |
| 1997年 | 45篇 |
| 1996年 | 39篇 |
| 1995年 | 35篇 |
| 1994年 | 20篇 |
| 1993年 | 15篇 |
| 1992年 | 10篇 |
| 1991年 | 9篇 |
| 1990年 | 8篇 |
| 1989年 | 7篇 |
| 1988年 | 5篇 |
| 1986年 | 2篇 |
| 1984年 | 1篇 |
| 1983年 | 1篇 |
| 1982年 | 1篇 |
| 1980年 | 1篇 |
| 1964年 | 1篇 |
排序方式： 共有5970条查询结果，搜索用时 15 毫秒
81.
Manoj K.
Muni Dayal R. Parhi Priyadarshi Biplab Kumar 《Computer Animation and Virtual Worlds》2020,31(3)
In this paper, grey wolf optimization controller (GWOC) is considered as a multiobjective technique for multiple humanoid navigations. Upon activation of GWOC, the humanoids mimic the group hunting behavior of grey wolves and navigate toward the target in a collision‐free manner in presence of both static and dynamic hurdles. The wolves in the pack will either diverge for searching prey or converge together for attacking the prey following the best search agent (Leader Alpha). GWOC has the ability to keep the humanoid free from being trapped in local minima whereas it facilitates it to head toward global minima. GWOC provides better results as compared to other intelligent techniques because of its five characteristics that include safe boundary, protection, following, hunting, and caring. Both simulation and experimental navigation in laboratory conditions for single as well as for multiple humanoid NAOs have been carried out. From the results of simulation and experimental data, it is confirmed that GWOC provides global minima for humanoid robots in complex environments with different shaped obstacles. A Petri‐net controller is considered while navigating multiple humanoids, as during multiple humanoid navigations, one humanoid robot acts as a dynamic obstacle to other humanoids. 相似文献
82.
Highly accurate real‐time localization is of fundamental importance for the safety and efficiency of planetary rovers exploring the surface of Mars. Mars rover operations rely on vision‐based systems to avoid hazards as well as plan safe routes. However, vision‐based systems operate on the assumption that sufficient visual texture is visible in the scene. This poses a challenge for vision‐based navigation on Mars where regions lacking visual texture are prevalent. To overcome this, we make use of the ability of the rover to actively steer the visual sensor to improve fault tolerance and maximize the perception performance. This paper answers the question of where and when to look by presenting a method for predicting the sensor trajectory that maximizes the localization performance of the rover. This is accomplished by an online assessment of possible trajectories using synthetic, future camera views created from previous observations of the scene. The proposed trajectories are quantified and chosen based on the expected localization performance. In this study, we validate the proposed method in field experiments at the Jet Propulsion Laboratory (JPL) Mars Yard. Furthermore, multiple performance metrics are identified and evaluated for reducing the overall runtime of the algorithm. We show how actively steering the perception system increases the localization accuracy compared with traditional fixed‐sensor configurations. 相似文献
83.
Jungwook Han Yonghoon Cho Jonghwi Kim Jinwhan Kim Nam‐sun Son Sun Young Kim 《野外机器人技术杂志》2020,37(6):987-1002
This study addresses the development of algorithms for multiple target detection and tracking in the framework of sensor fusion and its application to autonomous navigation and collision avoidance systems for the unmanned surface vehicle (USV) Aragon. To provide autonomous navigation capabilities, various perception sensors such as radar, lidar, and cameras have been mounted on the USV platform and automatic ship detection algorithms are applied to the sensor measurements. The relative position information between the USV and nearby objects is obtained to estimate the motion of the target objects in a sensor‐level tracking filter. The estimated motion information from the individual tracking filters is then combined in a central‐level fusion tracker to achieve persistent and reliable target tracking performance. For automatic ship collision avoidance, the combined track data are used as obstacle information, and appropriate collision avoidance maneuvers are designed and executed in accordance with the international regulations for preventing collisions at sea (COLREGs). In this paper, the development processes of the vehicle platform and the autonomous navigation algorithms are described, and the results of field experiments are presented and discussed. 相似文献
84.
M. Sanchiz F. Amadieu P.-V. Paubel A. Chevalier 《Behaviour & Information Technology》2020,39(10):1094-1109
ABSTRACT This study investigates how a search interface that displays users’ ultimate query (i.e. users’ current search goal) can cope with the age-related decrease of fluid abilities and support older users’ search behaviours. 30 young and 18 older adults completed 9 search problems with a regular web browser or with the experimental search interface. Results showed that older adults spent longer time on the search engine result pages, they needed more time to reformulate, and they had more difficulties exploring the search paths elaborated. Age-differences also appeared as soon as the beginning of the search. The support tool helped older users reformulate their queries more rapidly and elaborate more flexible search strategies at the beginning of the activity. Indeed, older adults who interacted with the support tool switched to the processing of a new search path more rapidly instead of exploiting their initial query (i.e. they visited fewer websites for the initial query produced and reformulated a query instead of keeping on conducting a deeper investigation of the search results provided in the search engine result page). Implications of these findings for the design of effective support tools for older users are discussed. 相似文献
85.
In an environment where robots coexist with humans, mobile robots should be human-aware and comply with humans' behavioural norms so as to not disturb humans' personal space and activities. In this work, we propose an inverse reinforcement learning-based time-dependent A* planner for human-aware robot navigation with local vision. In this method, the planning process of time-dependent A* is regarded as a Markov decision process and the cost function of the time-dependent A* is learned using the inverse reinforcement learning via capturing humans' demonstration trajectories. With this method, a robot can plan a path that complies with humans' behaviour patterns and the robot's kinematics. When constructing feature vectors of the cost function, considering the local vision characteristics, we propose a visual coverage feature for enabling robots to learn from how humans move in a limited visual field. The effectiveness of the proposed method has been validated by experiments in real-world scenarios: using this approach robots can effectively mimic human motion patterns when avoiding pedestrians; furthermore, in a limited visual field, robots can learn to choose a path that enables them to have the larger visual coverage which shows a better navigation performance. 相似文献
86.
87.
88.
本文在介绍某型飞机任务系统训练模拟器原理的基础上，阐述了基于PC／104嵌入式计算机的某型飞机惯屏模拟器的研制方案，给出了模拟系统的硬件电路框图和软件程序结构图，最后与某型飞机系统训练模拟器进行了组网导航训练测试，测试结果显示该模拟系统性能稳定，简单可靠，满足设计要求。 相似文献
89.
为了提高车载捷联惯导的对准精度和收敛速度,文中从信号源开始考虑,运用小波域阈值滤波方法对信号进行滤波,然后使用H..滤波来进行初始对准.最后,经过实际结果分析表明,采用小波域阈值滤波和H∞滤波滤波方法有效提高了收敛速度和对准精度,能够满足常规环境下车载导航的要求,有较大的工程实用价值. 相似文献
90.