全文获取类型
收费全文 | 7138篇 |
免费 | 291篇 |
国内免费 | 284篇 |
专业分类
电工技术 | 198篇 |
综合类 | 232篇 |
化学工业 | 68篇 |
金属工艺 | 387篇 |
机械仪表 | 1282篇 |
建筑科学 | 198篇 |
矿业工程 | 117篇 |
能源动力 | 70篇 |
轻工业 | 38篇 |
水利工程 | 14篇 |
石油天然气 | 18篇 |
武器工业 | 98篇 |
无线电 | 537篇 |
一般工业技术 | 306篇 |
冶金工业 | 26篇 |
原子能技术 | 40篇 |
自动化技术 | 4084篇 |
出版年
2024年 | 4篇 |
2023年 | 45篇 |
2022年 | 63篇 |
2021年 | 97篇 |
2020年 | 103篇 |
2019年 | 68篇 |
2018年 | 76篇 |
2017年 | 120篇 |
2016年 | 157篇 |
2015年 | 179篇 |
2014年 | 334篇 |
2013年 | 276篇 |
2012年 | 378篇 |
2011年 | 496篇 |
2010年 | 323篇 |
2009年 | 381篇 |
2008年 | 442篇 |
2007年 | 584篇 |
2006年 | 605篇 |
2005年 | 601篇 |
2004年 | 533篇 |
2003年 | 477篇 |
2002年 | 388篇 |
2001年 | 297篇 |
2000年 | 189篇 |
1999年 | 194篇 |
1998年 | 103篇 |
1997年 | 54篇 |
1996年 | 35篇 |
1995年 | 24篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 5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 |
1974年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有7713条查询结果,搜索用时 776 毫秒
61.
《Expert systems with applications》2014,41(15):6701-6717
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
62.
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
63.
《International journal of human-computer studies》2014,72(2):141-153
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
64.
《International journal of human-computer studies》2014,72(8-9):663-673
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
65.
Nicholas Taylor Jennifer Jenson Suzanne de Castell Barry Dilouya 《Journal of Computer-Mediated Communication》2014,19(4):763-779
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
66.
《Electronic Commerce Research and Applications》2014,13(6):409-422
The interest in 3D technology and virtual reality (VR) is growing both from academia and industry, promoting the quick development of virtual marketplaces (VMs) (i.e. e-commerce systems in VR environments). VMs have inherited trust problems, e.g. sellers may advertise a perfect deal but doesn’t deliver the promised service or product at the end. In view of this, we propose a five-sense feedback oriented reputation mechanism (supported by 3D technology and VR) particularly for VMs. The user study confirms that users prefer VMs with our reputation mechanism over those with traditional ones. In our reputation mechanism, five-sense feedback is objective and buyers can use it directly in their reputation evaluation of target sellers. However, for the scenarios where buyers only provide subjective ratings, we apply the approach of subjectivity alignment for reputation computation (SARC), where ratings provided by one buyer can then be aligned (converted) for another buyer according to the two buyers’ subjectivity. Evaluation results indicate that SARC can more accurately model sellers’ reputation than the state-of-the-art approaches. 相似文献
67.
王晓立 《网络安全技术与应用》2014,(10):133-134
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
68.
张锐 《网络安全技术与应用》2014,(6):182-182,184
高校计算机教学已成为现代技术应用的一门实践性较强的课程。依据高校局域网开发高效有用、快捷的基于虚拟现实的网络计算机教学系统,是高校教学方式改革的必然选择。本文依托高校网络资源平台,设计了基于X3D虚拟现实环境的计算机教学虚拟网络实验室,目的就是着眼X3D虚拟网络平台,实现高校计算机教学网络平台相关数据管理的调控与运做。这对于促进高校教育教学的数据流交换和实践教学管理意义明显。 相似文献
69.
70.