首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   17490篇
  免费   1987篇
  国内免费   1431篇
电工技术   892篇
综合类   2392篇
化学工业   203篇
金属工艺   1427篇
机械仪表   4795篇
建筑科学   418篇
矿业工程   503篇
能源动力   85篇
轻工业   185篇
水利工程   141篇
石油天然气   117篇
武器工业   313篇
无线电   1041篇
一般工业技术   963篇
冶金工业   140篇
原子能技术   39篇
自动化技术   7254篇
  2024年   131篇
  2023年   402篇
  2022年   638篇
  2021年   659篇
  2020年   673篇
  2019年   526篇
  2018年   591篇
  2017年   655篇
  2016年   698篇
  2015年   767篇
  2014年   1091篇
  2013年   1018篇
  2012年   1137篇
  2011年   1182篇
  2010年   935篇
  2009年   1001篇
  2008年   945篇
  2007年   1225篇
  2006年   1070篇
  2005年   967篇
  2004年   808篇
  2003年   689篇
  2002年   516篇
  2001年   505篇
  2000年   364篇
  1999年   254篇
  1998年   216篇
  1997年   244篇
  1996年   158篇
  1995年   148篇
  1994年   151篇
  1993年   107篇
  1992年   107篇
  1991年   81篇
  1990年   76篇
  1989年   68篇
  1988年   60篇
  1987年   10篇
  1986年   7篇
  1985年   8篇
  1984年   4篇
  1983年   5篇
  1982年   4篇
  1980年   2篇
  1979年   1篇
  1976年   1篇
  1973年   1篇
  1962年   1篇
  1956年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
针对在广域网环境下因较大网络时延造成遥操作工程机器人系统操作性能下降甚至系统不稳定的问题,提出一种神经网络控制方法。借助于广域网模拟器,在局域网环境下进行了不同网络时延下的位置阶跃响应和稳态跟踪实验研究。结果表明:与常规PID控制方法相比,该方法具有更好的动态和稳态特性,对网络时延具有较好的适应性和鲁棒性。研究结果对提高广域网环境下的遥操作工程机器人系统的操作性能具有指导意义。  相似文献   
72.
Performance evaluation is an important issue for optimal robot positioning within workcells. Performance indexes can provide essential contributions to such an evaluation, in particular if they can account for the specific task with respect to which the optimization is carried out.  相似文献   
73.
《Advanced Robotics》2013,27(8):767-777
In this paper, we propose an architecture for a cognitive robot based on tactile and visual information. Visual information contains various features such as location and area of various colored regions. Most of these features are irrelevant for object recognition to achieve the given task. In the architecture, tactile information plays a key role in the selection of visual features and discritization of selected features. In order to find appropriate visual features we use a correlation coefficient between the values of the features and action series. Then the ChiMerge algorithm is employed to discritize the value of the selected feature into a small number of intervals. Consequently, quantization of a state space to accomplish the given task is achieved. An appropriate behavior to the given task is acquired by using this state space with reinforcement learning algorithm. We give experimental results of computer simulation to show the validity of our method.  相似文献   
74.
《Advanced Robotics》2013,27(8-9):1075-1098
Abstract

This paper describes the transition motion from ladder climbing to brachiation for a multi-locomotion robot (MLR). The MLR has versatile modes of locomotion, such as biped walking, quadruped walking, brachiation and ladder climbing. The transition is a challenging motion, because the environmental boundaries change and the robot has to switch the form of its locomotion depending on its surroundings, situations and purposes. The robot supports itself with three end-effectors that maintain its stability, while one hand transfers from a rung on the vertical ladder to a new rung behind the robot for brachiation. A closed kinematic chain is formed by the robot links and the ladder. In this case, if the number of position-controlled active joints is greater than the number of the chain’s degrees of freedom, an internal stress appears because of unavoidable position errors. The huge internal stress may lead some motors to become overloaded. Since the safety of each motor is very important for a serial-link robot, a load-allocation algorithm is proposed to balance the loads of the joint motors. The algorithm is verified through experiments.  相似文献   
75.
《Advanced Robotics》2013,27(2):203-229
Robot motion is described by a set of positions and orientations of the robot's end-effector relative to some base coordinate system. Different methods to describe this motion are available and most of them are presented in this paper. Methods for position vector, free vector, and line vector transformation are presented and compared, and the advantages and disadvantages, the simplicity, and the number of arithmetic operations required of the different methods are addressed. An example of the application of these methods to a six degree-of-freedom robot is given.  相似文献   
76.
简述循环水电子-化学协合处理的基本原理及应用现状,通过电厂的应用实例,分析节能减排降耗的成效,对取得的经济效益进行了比较。  相似文献   
77.
Iterative Learning Control (ILC) captures interests of many scholars because of its capability of high precision control implement without identifying plant mathematical models, and it is widely applied in control engineering. Presently, most ILC algorithms still follow the original ideas of ARIMOTO, in which the iterative-learning-rate is composed by the control error with its derivative and integral values. This kind of algorithms will result in inevitable problems such as huge computation, big storage capacity for algorithm data, and also weak robust. In order to resolve these problems, an improved iterative learning control algorithm with fixed step is proposed here which breaks the primary thought of ARIMOTO. In this algorithm, the control step is set only according to the value of the control error, which could enormously reduce the computation and storage size demanded, also improve the robust of the algorithm by not using the differential coefficient of the iterative learning error. In this paper, the convergence conditions of this proposed fixed step iterative learning algorithm is theoretically analyzed and testified. Then the algorithm is tested through simulation researches on a time-variant object with randomly set disturbance through calculation of step threshold value, algorithm robustness testing,and evaluation of the relation between convergence speed and step size. Finally the algorithm is validated on a valve-serving-cylinder system of a joint robot with time-variant parameters. Experiment results demonstrate the stability of the algorithm and also the relationship between step value and convergence rate. Both simulation and experiment testify the feasibility and validity of the new algorithm proposed here. And it is worth to noticing that this algorithm is simple but with strong robust after improvements, which provides new ideas to the research of iterative learning control algorithms.  相似文献   
78.
王芳  崔丹丹  李林 《电子测量技术》2021,44(20):162-167
为了提升采摘机器人对果实的识别准确率以及定位定精度,提出一种基于深度学习Faster-RCNN框架的采摘机器人目标识别和定位算法.首先采用卷积神经网络VGG16模型提取输入图像的特性信息,并利用区域提议网络RPN生成含有目标的候选框,通过引入自适应候选框数的方法有效提升了算法性能,然后利用多任务损失函数对目标进行分类识...  相似文献   
79.
针对接管相贯线处的焊接特点,研发了悬挂式接管焊接机器人,介绍了机械结构特点和适用性.控制系统采用工业PC作为主控计算机和PMAC多轴控制卡进行多轴控制,利用二级控制结构实现作业管理,协调各轴运动完成焊接作业.进行了在筒体上外接管和内接管的焊接试验与在椭球体上外接管与内接管的焊接试验.结果表明,机器人的机械本体结构和控制系统能够实现多种接管的焊接需求,能够很好地完成接管相贯线处的焊接,提高了工作效率和焊接质量.  相似文献   
80.
段雪东 《山西建筑》2010,36(15):362-363
以长治市新闻大楼工程为例,介绍了圆弧斜切面顶板坐标放样施工技术,具体阐述了工艺原理、施工工艺流程及操作要点,提出了质量控制、成品保护、安全保证等措施,并进行了效益分析,为今后类似工程积累了经验。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号