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   24212篇
  免费   4862篇
  国内免费   4188篇
电工技术   1336篇
技术理论   2篇
综合类   2618篇
化学工业   824篇
金属工艺   319篇
机械仪表   825篇
建筑科学   554篇
矿业工程   132篇
能源动力   301篇
轻工业   316篇
水利工程   123篇
石油天然气   159篇
武器工业   88篇
无线电   2528篇
一般工业技术   1511篇
冶金工业   1939篇
原子能技术   29篇
自动化技术   19658篇
  2024年   355篇
  2023年   1972篇
  2022年   3071篇
  2021年   3033篇
  2020年   2440篇
  2019年   1631篇
  2018年   1145篇
  2017年   997篇
  2016年   1040篇
  2015年   1028篇
  2014年   1410篇
  2013年   1223篇
  2012年   1237篇
  2011年   1494篇
  2010年   1227篇
  2009年   1221篇
  2008年   1230篇
  2007年   1118篇
  2006年   959篇
  2005年   883篇
  2004年   690篇
  2003年   586篇
  2002年   535篇
  2001年   401篇
  2000年   342篇
  1999年   287篇
  1998年   265篇
  1997年   221篇
  1996年   181篇
  1995年   147篇
  1994年   114篇
  1993年   112篇
  1992年   93篇
  1991年   46篇
  1990年   47篇
  1989年   45篇
  1988年   29篇
  1987年   27篇
  1986年   41篇
  1966年   14篇
  1965年   24篇
  1964年   25篇
  1963年   23篇
  1962年   12篇
  1961年   17篇
  1959年   15篇
  1958年   16篇
  1957年   22篇
  1956年   13篇
  1955年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
In the past, the term e-learning referred to any method of learning that used electronic delivery methods. With the advent of the Internet however, e-learning has evolved and the term is now most commonly used to refer to online courses. A multitude of systems are now available to manage and deliver learning content online. While these have proved popular, they are often single-user learning environments which provide little in the way of interaction or stimulation for the student. As the concept of lifelong learning now becomes a reality and thus more and more people are partaking in online courses, researchers are constantly exploring innovative techniques to motivate online students and enhance the e-learning experience. This article presents our research in this area and the resulting development of CLEV-R, a Collaborative Learning Environment with Virtual Reality. This web-based system uses Virtual Reality (VR) and multimedia and provides communication tools to support collaboration among students. In this article, we describe the features of CLEV-R, its adaptation for mobile devices and present the findings from an initial evaluation.  相似文献   
992.
Euline   《Computers & Education》2008,51(4):1553-1568
This paper analyses the process of multimedia integration in English language classrooms equipped with interactive whiteboard (IWB) technology, and offers insights into the theoretical underpinnings of multimedia use in language learning from the perspective of cognitive learning theory. The data discussed here are drawn from a study carried out as part of a PhD research programme at Lancaster University (UK). The study was conducted within an interpretative research paradigm, and data were collected and analysed according to a qualitative approach. In the first part, the paper discusses some perceived pedagogical benefits of adopting a multimedia-oriented approach in the IWB-based classroom. Secondly, it discusses a variety of potential problems related to the use of multimedia resources in the language classroom in question. Finally, the paper draws upon the literature on multimedia learning to address the potential pedagogical implications of these research findings.  相似文献   
993.
John Wall  Vian Ahmed   《Computers & Education》2008,50(4):1383-1393
Continuing professional development (CPD) and life-long learning are vital to both individual and organisational success. For higher education, the intensive resource requirements requisite in the development of e-learning content and the challenges in accommodating different learning styles, developing an e-learning program can be a resource intensive exercise. A blended learning program has been developed in Ireland in an attempt to address the CPD needs of Irish construction professionals. This initiative attempts to strike a balance between the considerable resources required in the development of an e-learning initiative while addressing staff concerns in integrating technology in the delivery of programs. This pilot explores the issues encountered in integrating a simulation game, called MERIT, on a module as part of this blended learning program. The key finding from this research indicates that simulation games can play a very effective role in the delivery of lifelong learning opportunities aimed at the construction industry. However, management of the integration of a simulation game into a program requires careful planning, establishing key milestone dates and encouraging online collaboration through assigning of marks for effort and use of voice over IP communications.  相似文献   
994.
The widespread availability of digital learning resources in a variety of media formats offers the possibility to make a profound difference in education. This potential has not been fully realised for range of interrelated reasons. In this paper we study the key characteristics of learning resources that have proved effective in changing learning and teaching, and relate them to existing frameworks for understanding resources. We outline the relationships between resources, their users, and the way they are used, and explore issues that influence practitioners in choosing a particular resource. Our study is based on a review of resources for e-learning and chemistry in post-compulsory education, undertaken for the UK Joint Information Systems Committees (JISC), as part of a wider study examining ‘The Effectiveness of Resources, Tools and Support Services used by Tutors in Designing and Delivering E-Learning Activities’.  相似文献   
995.
This paper presents a system for monitoring and prognostics of machine conditions using soft computing (SC) techniques. The machine condition is assessed through a suitable ‘monitoring index’ extracted from the vibration signals. The progression of the monitoring index is predicted using an SC technique, namely adaptive neuro-fuzzy inference system (ANFIS). Comparison with a machine learning method, namely support vector regression (SVR), is also presented. The proposed prediction procedures have been evaluated through benchmark data sets. The prognostic effectiveness of the techniques has been illustrated through previously published data on several types of faults in machines. The performance of SVR was found to be better than ANFIS for the data sets used. The results are helpful in understanding the relationship of machine conditions, the corresponding indicating features, the level of damage/degradation and their progression.  相似文献   
996.
Throughout history, the development and widespread use of new technologies has impacted human cognition and social structures. By integrating a range of cognitive and socio-cultural theories we are better able to understand the impact of technological tools, such as the Internet, on children in the context of their local and global communities. An integrated theoretical approach enables us to more comprehensively ascertain the potential of the Internet to significantly impact children’s cognitive processes and the larger social implications of this global phenomenon. This paper presents a small-scale exploratory study that, through the development of an Internet-mediated learning model, examines the skills and characteristics of young, competent Internet-users engaged in informal Internet activities. At present, there is much conjecture on the ways in which the Internet may affect learning and this paper describes an approach to research that could inform future data collection procedures and analysis in empirical studies.  相似文献   
997.
Numerous educators have proposed the development of constructivist Internet-based learning environments for students. When creating the constructivist Internet-based learning environments, it is important for researchers to be aware of students’ preferences toward these environments. Through gathering data from 659 university students in Taiwan, this study developed a questionnaire to assess students’ preferences toward constructivist Internet-based learning environments. The questionnaire, with adequate validity and reliability, included 34 items on the following seven scales: relevance, multiple sources (and interpretations), challenge, student negotiation, cognitive apprenticeship, reflective thinking and epistemological awareness. The questionnaire responses revealed that male students tended to prefer the Internet-based learning environments where they could solve challenging problems, acquire cognitive apprenticeship and guidance from experts, and promote epistemological development than did female students. The findings also suggested that, if educators intend to develop Internet-based learning environments for more academically advanced students, such as graduate students, care should be taken to create more opportunities for them to negotiate ideas, obtain proper guidance, reflect their own thoughts, and explore epistemological issues. Finally, students with more Internet experiences tended to demand more on many features of the constructivist Internet-based learning environments than those with less Internet experiences.  相似文献   
998.
Student modelling is an important process for adaptive virtual learning environments. Student models include a range of information about the learners such as their domain competence, learning style or cognitive traits. To be able to adapt to the learners’ needs in an appropriate way, a reliable student model is necessary, but getting enough information about a learner is quite challenging. Therefore, mechanisms are needed to support the detection process of the required information. In this paper, we investigate the relationship between learning styles, in particular, those pertaining to the Felder–Silverman learning style model and working memory capacity, one of the cognitive traits included in the cognitive trait model. The identified relationship is derived from links between learning styles, cognitive styles, and working memory capacity which are based on studies from the literature. As a result, we demonstrate that learners with high working memory capacity tend to prefer a reflective, intuitive, and sequential learning style whereas learners with low working memory capacity tend to prefer an active, sensing, visual, and global learning style. This interaction can be used to improve the student model. Systems which are able to detect either only cognitive traits or only learning styles retrieve additional information through the identified relationship. Otherwise, for systems that already incorporate learning styles and cognitive traits, the interaction can be used to improve the detection process of both by including the additional information of a learning style into the detection process of cognitive traits and vice versa. This leads to a more reliable student model.  相似文献   
999.
Several researchers have recently investigated the connection between reinforcement learning and classification. We are motivated by proposals of approximate policy iteration schemes without value functions, which focus on policy representation using classifiers and address policy learning as a supervised learning problem. This paper proposes variants of an improved policy iteration scheme which addresses the core sampling problem in evaluating a policy through simulation as a multi-armed bandit machine. The resulting algorithm offers comparable performance to the previous algorithm achieved, however, with significantly less computational effort. An order of magnitude improvement is demonstrated experimentally in two standard reinforcement learning domains: inverted pendulum and mountain-car.  相似文献   
1000.
User simulation in a stochastic dialog system   总被引:1,自引:1,他引:0  
We present a new methodology of user simulation applied to the evaluation and refinement of stochastic dialog systems. Common weaknesses of these systems are the scarceness of the training corpus and the cost of an evaluation made by real users. We have considered the user simulation technique as an alternative way of testing and improving our dialog system. We have developed a new dialog manager that plays the role of the user. This user dialog manager incorporates several knowledge sources, combining statistical and heuristic information in order to define its dialog strategy. Once the user simulator is integrated into the dialog system, it is possible to enhance the dialog models by an automatic strategy learning. We have performed an extensive evaluation, achieving a slight but clear improvement of the dialog system.  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