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   3242篇
  免费   387篇
  国内免费   119篇
电工技术   51篇
技术理论   1篇
综合类   131篇
化学工业   129篇
金属工艺   12篇
机械仪表   72篇
建筑科学   298篇
矿业工程   23篇
能源动力   38篇
轻工业   320篇
水利工程   26篇
石油天然气   9篇
武器工业   19篇
无线电   276篇
一般工业技术   336篇
冶金工业   1078篇
原子能技术   6篇
自动化技术   923篇
  2024年   31篇
  2023年   101篇
  2022年   149篇
  2021年   203篇
  2020年   161篇
  2019年   143篇
  2018年   90篇
  2017年   112篇
  2016年   128篇
  2015年   110篇
  2014年   180篇
  2013年   177篇
  2012年   189篇
  2011年   235篇
  2010年   186篇
  2009年   202篇
  2008年   170篇
  2007年   140篇
  2006年   130篇
  2005年   107篇
  2004年   108篇
  2003年   93篇
  2002年   85篇
  2001年   102篇
  2000年   21篇
  1999年   28篇
  1998年   21篇
  1997年   18篇
  1996年   20篇
  1995年   14篇
  1994年   14篇
  1993年   13篇
  1992年   8篇
  1990年   6篇
  1989年   9篇
  1988年   8篇
  1985年   12篇
  1984年   8篇
  1983年   8篇
  1981年   7篇
  1965年   7篇
  1964年   22篇
  1963年   20篇
  1961年   13篇
  1960年   16篇
  1959年   13篇
  1958年   10篇
  1957年   14篇
  1956年   7篇
  1955年   18篇
排序方式: 共有3748条查询结果,搜索用时 93 毫秒
101.
Eirik  Jan 《Computers & Security》2009,28(6):476-490
Empirical findings from surveys and in-depth interviews with information security managers and users indicate that a digital divide exists between these groups in terms of their views on and experience of information security practices. Information security professionals mainly regard users as an information security threat, whereas users believe themselves that they are an untapped resource for security work. The limited interaction between users and information security managers results in a lack of understanding for the other's point of view. These divergent views on and interpretations of information security mean that managers tend to base their practical method on unrealistic assumptions, resulting in management approaches that are poorly aligned with the dynamics of the users' working day.  相似文献   
102.
Accurate detection of mediated haptic information in minimally invasive surgery (MIS) is critical for applying appropriate force magnitudes onto soft tissue with the aim of minimising tissue trauma. Force perception in MIS is a dynamic process, with surgeons’ administration of force into tissue revealing information about the remote surgical site which further informs the surgeons’ haptic interactions. The relationship between applied force and material deformation rate provides biomechanical information specifying the deformation distance remaining until a tissue will fail: which is termed distance-to-break (DTB). The current study demonstrates that observers can detect DTB while deforming simulated tissues and stop before reaching the tissues’ failure points. The design of training simulators, control devices and automated robotic systems for applications outside of MIS is discussed.

Practitioner Summary: In MIS, haptic information is critical for applying appropriate forces onto soft tissue to minimise tissue trauma. Observers used force information to detect how far they could deform a virtual tissue before it would break. The design of training simulators, control devices and automated robotic systems is discussed.  相似文献   

103.
Compared with driving or flight simulation, little is known about self-motion perception in riding simulation. The goal of this study was to examine whether or not continuous roll motion supports the sensation of leaning into bends in dynamic motorcycle simulation. To this end, riders were able to freely tune the visual scene and/or motorcycle simulator roll angle to find a pattern that matched their prior knowledge. Our results revealed idiosyncrasy in the combination of visual and proprioceptive information. Some subjects relied more on the visual dimension, but reported increased sickness symptoms with the visual roll angle. Others relied more on proprioceptive information, tuning the direction of the visual scenery to match three possible patterns. Our findings also showed that these two subgroups tuned the motorcycle simulator roll angle in a similar way. This suggests that sustained inertially specified roll motion have contributed to the sensation of leaning in spite of the occurrence of unexpected gravito-inertial stimulation during the tilt. Several hypotheses are discussed.

Practitioner Summary: Self-motion perception in motorcycle simulation is a relatively new research area. We examined how participants combined visual and proprioceptive information. Findings revealed individual differences in the visual dimension. However, participants tuned the simulator roll angle similarly, supporting the hypothesis that sustained inertially specified roll motion contributes to a leaning sensation.  相似文献   

104.
As the population of elderly people in society rises, the importance of technology to assist health management is growing with the demographic shift. Wearable personal computing has been the common solution proposed by related projects to fulfil the needs of elderly people. These add-on devices are attached to the users, and result in uneasiness or discomfort while wearing them in public areas. In this study, three common wearing positions – wrist, upper arm, and neck – were investigated in terms of psychological perception and perceived readability. Twenty-four Taiwanese participants in Miaoli area were asked to wear the designed prototypes for a certain time. The participants completed questionnaires and participated in an open-ended interview. Data of psychological perceptions, visibility, and readability about wearable devices were collected. The results evidenced that the personal attributes of gender, smart device user, and requirement for medical care affect the psychological perception and user attitudes. The statistical results indicated significant differences in elderly people's attitudes towards wearable devices attached to different parts of the body. The wrist was the most favourable location to attach a wearable device.  相似文献   
105.
This research assessed how emotive animated agents in a simulation‐based training affect the performance outcomes and perceptions of the individuals interacting in real time with the training application. A total of 56 participants consented to complete the study. The material for this investigation included a nursing simulation in which participants interacted with three animated agents. The results of this investigation indicated that both experienced and novice participants focused more visual attention time on the body of the animated agent than the other defined areas of interest in the simulated environment. The results also indicated that novice participants conveyed more neutral facial expressions during the interaction with the animated agents than experience participants. The results of the simulation performance scores indicated that novice participants achieved higher simulation performance scores on the simulation task than experienced participants. Lastly, the results of the agent persona instrument showed that experienced and novice participants perceived the animated agents as facilitators of learning, credible, human‐like and engaging.  相似文献   
106.
针对彩色视频压缩过程中压缩率不高或者视频质量损失过大的问题,提出一种基于视觉感知模型与色差的自适应视频压缩预处理算法。首先,在颜色对比敏感度模型中,人类视觉对高色度区域的色差敏感度较低,因此为不同色度区域分配不同的压缩权重;然后,基于帧之间的偏差图建立运动预测帧的空间运动模型,降低了高运动区域的残差;最终,使用动态的色调映射函数来控制视频的压缩等级,从而保证视频的视觉质量。基于多组视频进行实验,本算法成功地将标准的压缩软件提高了35%的压缩率,但同时可看出,本算法的性能依赖于具体的视频上下文。  相似文献   
107.
The universal force field (UFF) is a broadly applicable classical force field that contains parameters for almost every atom type of the periodic table. This force field is non-reactive, i.e. the topology of the system under study is considered as fixed and no creation or breaking of covalent bonds is possible. This paper introduces interactive modeling-UFF (IM-UFF), an extension of UFF that combines the possibility to significantly modify molecular structures (as with reactive force fields) with a broad diversity of supported systems thanks to the universality of UFF. Such an extension lets the user easily build and edit molecular systems interactively while being guided by physics based inter-atomic forces. This approach introduces weighted atom types and weighted bonds, used to update topologies and atom parameterizations at every time step of a simulation. IM-UFF has been evaluated on a large set of benchmarks and is proposed as a self-contained implementation integrated in a new module for the SAMSON software platform for computational nanoscience available at http://www.samson-connect.net.  相似文献   
108.
Vision‐based aircraft detection technology may provide a credible sensing option for automated detect and avoid in small‐to‐medium size fixed‐wing unmanned aircraft systems (UAS). Reliable vision‐based aircraft detection has previously been demonstrated in sky‐region sensing environments. This paper describes a novel vision‐based system for detecting aircraft below the horizon in the presence of ground clutter. We examine the performance of our system on a data set of 63 near collision encounters we collected between a camera‐equipped manned aircraft and a below‐horizon target. In these 63 encounters, our system successfully detects all aircraft, at an average detection range of 1890 m (with a standard error of 43 m and no false alarms in 1.1 h). Furthermore, our system does not require access to inertial sensor data (which significantly reduces system cost) and operates at over 12 frames per second.  相似文献   
109.
目前物流运输配送安全管理主要依靠GPS技术进行管理, 缺乏整体安全管理技术手段. 提出了一种物流物联网监控技术. 该技术实现了物联网传感器系统、视频监控系统、单兵可视通话指挥系统、司乘人员终端、通讯系统等技术的综合应用. 通过实际项目应用, 验证了该技术可以广泛应用于实现保障运输安全、提高运输效率、管理运输绩效、处理应急情况等.  相似文献   
110.
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