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   9920篇
  免费   636篇
  国内免费   468篇
电工技术   274篇
综合类   594篇
化学工业   96篇
金属工艺   428篇
机械仪表   1528篇
建筑科学   402篇
矿业工程   193篇
能源动力   85篇
轻工业   66篇
水利工程   46篇
石油天然气   38篇
武器工业   148篇
无线电   828篇
一般工业技术   537篇
冶金工业   128篇
原子能技术   49篇
自动化技术   5584篇
  2024年   23篇
  2023年   113篇
  2022年   162篇
  2021年   242篇
  2020年   258篇
  2019年   154篇
  2018年   168篇
  2017年   208篇
  2016年   226篇
  2015年   256篇
  2014年   489篇
  2013年   448篇
  2012年   530篇
  2011年   661篇
  2010年   479篇
  2009年   571篇
  2008年   646篇
  2007年   762篇
  2006年   805篇
  2005年   773篇
  2004年   678篇
  2003年   604篇
  2002年   499篇
  2001年   387篇
  2000年   247篇
  1999年   237篇
  1998年   133篇
  1997年   68篇
  1996年   49篇
  1995年   35篇
  1994年   21篇
  1993年   14篇
  1992年   8篇
  1991年   6篇
  1990年   7篇
  1989年   7篇
  1987年   3篇
  1986年   3篇
  1985年   7篇
  1984年   6篇
  1983年   4篇
  1982年   4篇
  1981年   2篇
  1980年   2篇
  1979年   2篇
  1977年   3篇
  1975年   2篇
  1973年   2篇
  1958年   2篇
  1955年   2篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
51.
Partner selection and transportation scheduling are critical to the success of a Virtual Enterprise. Collaborative transportation is a promising strategy that can help many enterprises survive and thrive in today’s highly competitive market. To help decision makers establish and operate Virtual Enterprises more effectively, an innovative decision support system is proposed in this paper. First, new model for integration of partner selection and collaborative transportation scheduling in Virtual Enterprises is developed. This integrated optimisation problem is very dynamic in nature and it is required to optimise a number of interlinked sub-problems at the same time. Then, a novel Genetic Algorithm with a unique dynamic chromosome representation and genetic operations is developed to find an optimal solution to the integrated problem. The effectiveness of the proposed approach is demonstrated in a representative case study.  相似文献   
52.
采用主监视窗扩展技术的增强现实三维注册方法   总被引:1,自引:0,他引:1  
在增强现实三维注册中,采用重新检测策略时顿卡现象严重。提出一种采用主监视窗扩展技术的增强现实三维注册方法。在检测阶段,引入特征点可信度和主监视窗,并设计主监视窗的分割、扩展和调控策略,大幅提升了计算速度;在跟踪阶段,采用基于图像金字塔的光流算法进行特征点跟踪。实验证明,该方法不仅有效缓解了顿卡现象,也提升了系统整体的实时性。  相似文献   
53.
In this paper, we propose a new continuous self‐collision detection (CSCD) method for a deformable surface that interacts with a simple solid model. The method is developed based on the radial‐view‐based culling method. Our method is suitable for the deformable surface that has large contact region with the solid model. The deformable surface may consist of small round‐shaped holes. At the pre‐processing stage, the holes of the deformable surface are filled with ghost triangles so as to make the mesh of the deformable surface watertight. An observer primitive (i.e. a point or a line segment) is computed so that it lies inside the solid model. At the runtime stage, the orientations of triangles with respect to the observer primitive are evaluated. The collision status of the deformable surface is then determined. We evaluated our method for several animations including virtual garments. Experimental results show that our method improves the process of CSCD.  相似文献   
54.
We address the problem of robust and efficient treatment of element collapse and inversion in corotational FEM simulations of deformable objects in two and three dimensions, and show that existing degeneration treatment methods have previously unreported flaws that seriously threaten robustness and physical plausibility in interactive applications. We propose a new method that avoids such flaws, yields faster and smoother degeneration recovery and extends the range of well‐behaved degenerate configurations without adding significant complexity or computational cost to standard explicit and quasi‐implicit solvers.  相似文献   
55.
Owing to the popularity of various hand tracking interfaces, there have been numerous applications developed to provide intuitive hand interaction with the virtual world. As users start with great anticipation, they end up with dissatisfaction due to difficulties of manipulation or physical tiredness coming very short. Although the task itself is rather trivial in a real life situation, it requires much effort in the virtual environment. We address this awkwardness as ‘VR interaction-induced fatigue symptom’ and hypothesize its causes based on our observations. We argue that the source of the fatigue comes from the restricted sensory information of the VR interfaces, and that users try to accommodate the missing sensory feedback by excessive motion leading to wrong posture or bad timing. We demonstrate our hypothesis by conducting experiments of two types of virtual interaction scenarios: object transport and 3D selection. Furthermore, by analyzing the behaviors of users' action collected from our experiment, we derive essential factors to be considered in designing VR applications, and propose a conceptual interaction model for orchestrating virtual grasping.  相似文献   
56.
Relaxation training is an application of affective computing with important implications for health and wellness. After detecting user׳s affective state through physiological sensors, a relaxation training application can provide the user with explicit feedback about his/her detected affective state. This process (biofeedback) can enable an individual to learn over time how to change his/her physiological activity for the purposes of improving health and performance. In this paper, we provide three contributions to the field of affective computing for health and wellness. First, we propose a novel application for relaxation training that combines ideas from affective computing and games. The game detects user׳s level of stress and uses it to influence the affective state and the behavior of a 3D virtual character as a form of embodied feedback. Second, we compare two algorithms for stress detection which follow two different approaches in the affective computing literature: a more practical and less costly approach that uses a single physiological sensor (skin conductance), and a potentially more accurate approach that uses four sensors (skin conductance, heart rate, muscle activity of corrugator supercilii and zygomaticus major). Third, as the central motivation of our research, we aim to improve the traditional methodology employed for comparisons in affective computing studies. To do so, we add to the study a placebo condition in which user׳s stress level, unbeknown to him/her, is determined pseudo-randomly instead of taking into account his/her physiological sensor readings. The obtained results show that only the feedback presented by the single-sensor algorithm was perceived as significantly more accurate than the placebo. If the placebo condition was not included in the study, the effectiveness of the two algorithms would have instead appeared similar. This outcome highlights the importance of using more thorough methodologies in future affective computing studies.  相似文献   
57.
As research on virtual worlds gains increasing attention in educational, commercial, and military domains, a consideration of how player populations are ‘reassembled’ through social scientific data is a timely matter for communication scholars. This paper describes a large‐scale study of virtual worlds in which participants were recruited at public gaming events, as opposed to through online means, and explores the dynamic relationships between players and contexts of play that this approach makes visible. Challenging conventional approaches to quantitatively driven virtual worlds research, which categorizes players based on their involvement in an online game at a particular point in time, this account demonstrates how players' networked gaming activities are contingent on who they are playing with, where, and when.  相似文献   
58.
现阶段,在实验教学硬件设备要求较高而实验教学改革注重综合能力培养的指导下,很多依靠计算机硬件设备开展的实验课程遇到了较大的挑战.本文根据独立学院的具体情况结合虚拟机技术的特点,具体的分析了虚拟机技术在计算机实践教学中能起到的巨大作用和广阔的应用前景.并倡导全国独立院校要善于通过模拟真实的环境,去探索和研究科学的东西,提高自己的实践教学和科研水平.  相似文献   
59.
基于Virtool软件的虚拟现实技术应用在谢公祠的保护和研究中,可以实现虚拟体验、时空转换、构件分析等交互功能.本文介绍了实现这些功能的软件处理方法以及效果,展望了该软件用于建筑保护工作和科学普及的应用前景.  相似文献   
60.
针对目前计算机实践教学中存在的问题,提出了一种虚拟机技术的解决方法。该方法不仅充分有效地利用现有设备,而且对硬件及系统具有很好的安全性,并能够增加学生的实践动手机会。教学上更加灵活、方便地设计实践项目,从而提高实践教学的质量。  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