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   9508篇
  免费   357篇
  国内免费   382篇
电工技术   236篇
综合类   681篇
化学工业   126篇
金属工艺   442篇
机械仪表   1644篇
建筑科学   292篇
矿业工程   241篇
能源动力   89篇
轻工业   111篇
水利工程   23篇
石油天然气   96篇
武器工业   100篇
无线电   697篇
一般工业技术   376篇
冶金工业   124篇
原子能技术   41篇
自动化技术   4928篇
  2024年   5篇
  2023年   52篇
  2022年   78篇
  2021年   116篇
  2020年   134篇
  2019年   89篇
  2018年   105篇
  2017年   138篇
  2016年   185篇
  2015年   217篇
  2014年   443篇
  2013年   404篇
  2012年   524篇
  2011年   657篇
  2010年   461篇
  2009年   481篇
  2008年   582篇
  2007年   783篇
  2006年   768篇
  2005年   764篇
  2004年   723篇
  2003年   676篇
  2002年   532篇
  2001年   394篇
  2000年   245篇
  1999年   270篇
  1998年   142篇
  1997年   76篇
  1996年   54篇
  1995年   40篇
  1994年   24篇
  1993年   20篇
  1992年   6篇
  1991年   8篇
  1990年   5篇
  1989年   5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10000条查询结果,搜索用时 15 毫秒
1.
Complementary modelling of fluid separation processes   总被引:1,自引:0,他引:1  
Optimal functioning of numerous technological processes depends primarily on relevant process design, properly selected column internals and sufficient understanding of the process behaviour. This can be achieved only with the help of accurate and reliable process models capable of considering process rates in a rigorous way, with respect to both transport phenomena and chemistry. In this article, a new modelling concept called complementary modelling is suggested for a large class of fluid separation processes. Since the conditions and criteria for these processes vary considerably, it is impossible to develop a unified modelling approach. Instead, a reasonable and effective combination of different modelling approaches provides solutions to many present and future tasks. The complementary modelling is discussed in detail and illustrated with several case studies.  相似文献   
2.
In this paper, we present the findings from an extensive study of the use of virtual reality (VR) models in large construction projects. The study includes two parts: The first part presents a quantitative questionnaire designed to investigate how VR models are experienced and assessed by the workforce at a building site. The second part includes a qualitative field survey of how VR models can be applied and accepted by professionals in the design and planning process of a large pelletizing plant. Through mainly studying persons who had little or no experience with advanced information technology (IT), we hoped to reveal the attitudes of the average person working at a construction site rather than of an IT expert. In summary, the study shows that the VR models in both projects have been very useful and well accepted by the users. Today’s information flow is, from a general point of view, considered to be insufficient and the hypothesis is that using VR models in the construction process have the potential to minimize waste of resources and improve the final result.  相似文献   
3.
河南稠油资源品位低,开采难度大,效益差。近几年,通过实践,逐渐摸索出一套适应开发需要的科学生产管理方法,明显地改善了稠油开发效果。以提高热效率为核心,形成了八大生产管理制度;深化油藏认识,使油藏-工艺-管理三者有机结合,充分利用了地层储热,提高了周期吞吐开发水平;以降粘、防砂、堵窜为重点,实现了地面-井筒-油层三位一体工艺配套,保证了油井正常生产。  相似文献   
4.
We present a digital laboratory safety training platform called AALTOLAB which we have developed to address the need for more flexible and engaging ways to teach laboratory safety for chemical engineers. AALTOLAB consists of an interactive, web-based 360° virtual laboratory, integrated with a Moodle-based digital exam with automatic assessment. The modular platform offers different modules from general comprehensive laboratory training to more specialised modules. Students and staff can freely navigate in the laboratory rooms at any time and interact with different action points including interactive videos, slideshows, and minigames. Our technical solution allows teachers even with limited technological skills to easily modify the training materials in real time. The relationship of students’ learning experiences and level of learning is also discussed. We believe that our safety training concept facilitates deep learning and students’ engagement, thus improving safety culture in our laboratories.  相似文献   
5.
Advanced online product presentation technologies such as virtual mirrors enable consumers to experience products like they are actually present with them in the real world. This study is one of the first to address the mechanism underlying this phenomenon. Inspired by literature on media technology the concept of local presence is put forward and applied to the online consumer behavior domain. A key objective of this paper is to examine whether local presence adds to our understanding of how emerging product presentation formats influence online product experiences. To this end, a laboratory experiment (N = 366) was conducted with product presentation format as a three level (pictures, 360-spin rotation, and virtual mirror) independent variable, allowing for a comparison of the effectiveness of different presentation formats in creating perceptions of local presence. As a second objective, the influence of local presence on perceptions of product tangibility and product likability, two key facets of the online product experience, were assessed. The results, obtained with the use of analysis of variance and partial least squares modeling, show the superiority of the virtual mirror in creating local presence, and demonstrate that local presence is highly predictive of product tangibility and product likability. Theoretical and managerial implications are discussed.  相似文献   
6.
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   
7.
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   
8.
随着全球网络技术与移动通信设备的融合发展,“大数据”时代已经引起社会各界的重点关注。苹果、三星、华为、IBM、微软、腾讯等国际知名企业都开始建构出“大数据”时代的企业生态系统。本文将对“大数据”时代的企业生态系统的演化和建构进行深入分析。  相似文献   
9.
文章力图以VR(虚拟现实)技术手段应用于城市地下步行商业街规划设计,来解决当前传统规划手段地下步行商业街规划中普遍存在的对其心理环境构筑的忽视和考虑不完善的诟病,以期最大限度消除规划设计中消极空间的产生,并对其关键技术进行了研究和探讨  相似文献   
10.
微博作为新兴的传播交流媒介以其传播速度快、互动性强、即时收发等优势得到迅速的普及,促使网络营销活动的发展步伐不断加速。本文提出,要加快企业的营销活动变革的步伐,在实践的基础上,分析了微博营销的特点,提出了运用的主要方法,归纳了企业实施微博营销后所取得的效果,以较好地适应网络时代消费者更快、更省、更便捷的消费需求。  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