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   495篇
  免费   14篇
  国内免费   2篇
电工技术   15篇
综合类   1篇
化学工业   149篇
金属工艺   4篇
机械仪表   6篇
建筑科学   13篇
能源动力   38篇
轻工业   65篇
水利工程   1篇
石油天然气   14篇
无线电   25篇
一般工业技术   93篇
冶金工业   12篇
原子能技术   23篇
自动化技术   52篇
  2024年   1篇
  2023年   3篇
  2022年   10篇
  2021年   10篇
  2020年   6篇
  2019年   10篇
  2018年   10篇
  2017年   7篇
  2016年   30篇
  2015年   9篇
  2014年   18篇
  2013年   40篇
  2012年   35篇
  2011年   52篇
  2010年   36篇
  2009年   25篇
  2008年   29篇
  2007年   22篇
  2006年   23篇
  2005年   20篇
  2004年   19篇
  2003年   13篇
  2002年   10篇
  2001年   1篇
  2000年   4篇
  1999年   11篇
  1998年   9篇
  1997年   11篇
  1996年   5篇
  1995年   6篇
  1994年   3篇
  1993年   4篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1974年   1篇
排序方式: 共有511条查询结果,搜索用时 15 毫秒
51.
We present a method through which domestic service robots can comprehend natural language instructions. For each action type, a variety of natural language expressions can be used, for example, the instruction, ‘Go to the kitchen’ can also be expressed as ‘Move to the kitchen.’ We are of the view that natural language instructions are intuitive and, therefore, constitute one of the most user-friendly robot instruction methods. In this paper, we propose a method that enables robots to comprehend instructions spoken by a human user in his/her natural language. The proposed method combines action-type classification, which is based on a support vector machine, and slot extraction, which is based on conditional random fields, both of which are required in order for a robot to execute an action. Further, by considering the co-occurrence relationship between the action type and the slots along with the speech recognition score, the proposed method can avoid degradation of the robot’s comprehension accuracy in noisy environments, where inaccurate speech recognition can be problematic. We conducted experiments using a Japanese instruction data-set collected using a questionnaire-based survey. Experimental results show that the robot’s comprehension accuracy is higher in a noisy environment using our method than when using a baseline method with only a 1-best speech recognition result.  相似文献   
52.
Mechanical strengthening of a Si cantilever by applying KOH wet etching was investigated. Two kinds of Si cantilever specimens having the different crystallographic orientations of the sidewall surfaces, i.e., Si{100} and Si{110}, were fabricated from the same SOI wafer by a Bosch process. The typical height and pitch of the scalloping formed on the sidewall were 248 and 917 nm, respectively. A 50 % KOH (40 °C) chemical wet etching was applied to increase the fracture stress of the Si cantilever. The fracture stress in the both of Si{100} and Si{110} cantilevers increased with the advance of the etching. The obtained maximum fracture stress in Si{100} and Si{110} were 4.2 and 3.7 GPa, respectively. Sidewall surface of the cantilever was analyzed to investigate the mechanical strengthening of Si cantilever by wet etching. The etched surface crystalline was analyzed by the transmission electron microscope (TEM), and confirmed that the thickness of the affected flow layer was less than 10 nm from the obtained TEM image. Then the change of the surface roughness by the KOH etching was analyzed by the atomic force microscope. The surface was smoothened with the advance of the KOH etching. The roughness value of Ra in Si{100} and Si{110} decreased to 12.1 and 37.7 nm, respectively.  相似文献   
53.
On March 11, 2011, a massive earthquake (magnitude 9.0) and accompanying tsunami hit the Tohoku region of eastern Japan. Since then, the Fukushima Daiichi Nuclear Power Plants have been facing a crisis due to the loss of all power that resulted from the meltdown accidents. Three buildings housing nuclear reactors were seriously damaged from hydrogen explosions, and, in one building, the nuclear reactions became out of control. It was too dangerous for humans to enter the buildings to inspect the damage because radioactive materials were also being released. In response to this crisis, it was decided that mobile rescue robots would be used to carry out surveillance missions. The mobile rescue robots needed could not be delivered to the Tokyo Electric Power Company (TEPCO) until various technical issues were resolved. Those issues involved hardware reliability, communication functions, and the ability of the robots' electronic components to withstand radiation. Additional sensors and functionality that would enable the robots to respond effectively to the crisis were also needed. Available robots were therefore retrofitted for the disaster reponse missions. First, the radiation tolerance of the electronic componenets was checked by means of gamma ray irradiation tests, which were conducted using the facilities of the Japan Atomic Energy Agency (JAEA). The commercial electronic devices used in the original robot systems operated long enough (more than 100 h at a 10% safety margin) in the assumed environment (100 mGy/h). Next, the usability of wireless communication in the target environment was assessed. Such tests were not possible in the target environment itself, so they were performed at the Hamaoka Daiichi Nuclear Power Plants, which are similar to the target environment. As previously predicted, the test results indicated that robust wireless communication would not be possible in the reactor buildings. It was therefore determined that a wired communication device would need to be installed. After TEPCO's official urgent mission proposal was received, the team mounted additional devices to facilitate the installation of a water gauge in the basement of the reactor buildings to determine flooding levels. While these preparations were taking place, prospective robot operators from TEPCO trained in a laboratory environment. Finally, one of the robots was delivered to the Fukushima Daiichi Nuclear Power Plants on June 20, 2011, where it performed a number of important missions inside the buildings. In this paper, the requirements for the exploration mission in the Fukushima Daiichi Nuclear Power Plants are presented, the implementation is discussed, and the results of the mission are reported.  相似文献   
54.
Most control methods of underwater vehiclemanipulator systems (UVMS) are based on the computed torque method that is used for underwater robotic vehicles. We have proposed a resolved acceleration control (RAC) method for UVMS. In this article, we propose a disturbance compensation control method for both vehicle and manipulator based on the RAC method. Experimental results using an underwater robot with a vertical planar 2-link manipulator show that the proposed control method has good control performance.  相似文献   
55.
The ability to maintain the separation between positive emotion and negative emotion in times of stress has been construed as a resilience mechanism. Emotional resiliency is particularly relevant in old age given concomitant declines in cognitive performance. In the present study, the authors examined the dynamical linkages among positive emotion, negative emotion, and cognition as individuals performed a complex cognitive task. Comparisons were made between younger (n = 63) and older (n = 52) age groups. Older adults manifested significant unidirectional coupling from negative emotion to cognitive performance; younger adults manifested significant unidirectional coupling from negative emotion to positive emotion and from cognitive performance to both positive and negative emotions. Implications for age differences in emotion regulatory strategies are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
56.
Model elimination is a back-chaining strategy to search for and construct resolution refutations. Recent extensions to model elimination, implemented in Modoc, have made it a practical tool for satisfiability checking, particularly for problems with known goals. Many formulas can be refuted more succinctly by recording certain derived clauses, called lemmas. Lemmas can be used where a clause of the original formula would normally be required. However, recording too many lemmas overwhelms the proof search. Lemma management has a significant effect on the performance of Modoc. Earlier research studied pure persistent (global) strategies, and pure unit-lemma (local) strategies. This paper describes and evaluates a hybrid strategy to control the lifetime of lemmas, as well as a new technique for deriving certain lemmas efficiently, using a lazy strategy. Unit lemmas are recorded locally as in previous practice, but certain lemmas that are considered valuable are asserted globally. A range of functions for estimating value is studied experimentally. Criteria are reported that appear to be suitable for a wide range of application-derived formulas.  相似文献   
57.
对于如何提供补丁下载,单机PC游戏开发人员已经是轻车熟路了,这些补丁包里通常包含玩家需要手动更新的数据和二进制文件.但基本上.他们很少会为了补丁下载而创建一个“更新系统”。  相似文献   
58.
Underwater vehicle-manipulator systems (UVMS) are expected to play an important role in ocean exploration. It is considered that UVMS will be operated by both automatic and manual control. We have proposed an automatic control method. In this article, we propose a master-slave system for a UVMS. The effectiveness of the proposed master-slave control system is demonstrated by using a floating underwater robot with a 2-link manipulator.  相似文献   
59.
This paper presents an analysis of overflow processes from a PH1 + PH2/M/S/K queue having two independent phase type renewal input streams. Both the superposed overflow process and individual overflow processes for the PH1- and PH2-streams are analyzed using first passage time distributions for the number of customers in the system. Each overflow process is characterized as a Markov renewal process. The nth moment of the number of customers in an infinite server group to which these overflows have been offered is derived using a theory for the MR/M/∞ queue with a Markov renewal input. The numerical examples for means and variance-to-mean ratios (peakednesses) of the individual overflow streams are given for an H2 + H2/M/S/S queue with interrupted Poisson inputs, which is a vital model for telephone network planning. In addition, overflow traffic characteristics are discussed by using these examples.  相似文献   
60.
The coalescence of two growing bubbles presents unique characteristics compared to static bubble coalescence. The gas injection flowrate significantly affects the different stages of bubble evolution, which is poorly understood. In this study, we investigate the flowrate effects on the lateral coalescence of two growing bubbles experimentally. The synchronous bubbling from adjacent needles is achieved using water to push air. During the bubble growth process, we find that the initial nonlinear evolution of bubble volume is because the bubble emerges as a small spherical cap with a large curvature radius and apparent contact angle. As the neck expands after bubble coalescence, the injection flowrate accelerates the neck evolution compared to the case without air injection. We find the neck expansion time decreases linearly with increasing flowrate, while the expansion speed increases with flowrate, but only in the early stage. Moreover, we propose a new theoretical expression that predicts the neck radius well at all the flowrates. At the post-coalescence oscillation stage, the average projection area of the coalesced bubble increases linearly with time, except for periodic oscillations. Besides, we find that the injected air primarily influences the coalesced bubble's height, which in turn affects the projection area.  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