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41.
Using a framework of cognitive, social, and teaching presence, the nature of learning experiences in a three-dimensional virtual world environment (Second Life) and a text-chat learning environment without visuals (TeachNet) were investigated. A mixed method of code frequencies, coherence graphs, interviews, and a survey was used. The results revealed that the TeachNet debates included more cognitive presence codes that indicate higher levels of cognitive processing than in SL debates. The teams were significantly different from each other in the collaboration style for developing arguments and in the ways to use utterances associated with cognitive, social, and teaching presences, and the groups’ collaboration style became more established with more experience with the tasks. The three critical factors–tool, tasks and group cohesion–that affect cognitive, teaching, and social presence are discussed.  相似文献   
42.
Since a large variety of digital games have been used in many fields for educational purposes, their real functions in learning have caught much attention as well. This study first defines learning characteristics of problem-solving digital games and their corresponding cognitive levels, then designs and develops a problem-solving game in accordance to the criteria. Tasks in the game context are inter-related to each other so that players need to critically and creatively think about problem solutions. Learners’ task analyses are performed to observe four elementary learners’ gaming paths, behaviors and cognitive activities, individually and collaboratively. System documentation, video recording, researcher observation, and interviews are conducted to analyze learners’ learning strategies and their cognitive performance during the gaming process.  相似文献   
43.
This study investigated the online practices of students enrolled in graduate-level distance education courses. Using interviews and a questionnaire as data sources, the study sought to: (a) identify common practices that students adopt in asynchronous discussions, and (b) gain an understanding of why students adopt them. An analysis of the data suggests that many of the practices are coping mechanisms developed to help students more easily meet course participation requirements. Some of these are time saving strategies designed to reduce information overload (e.g., skimming messages rather than reading them carefully). Other strategies are designed to help students project an image of themselves as knowledgeable and collaborative course participants. It is argued that although these practices provide students with a level of efficiency in terms of meeting course requirements, they may inadvertently undermine learning.  相似文献   
44.
This paper reports the results of a study which aimed to investigate how ubiquitous games influence English learning achievement and motivation through a context-aware ubiquitous learning environment. An English curriculum was conducted on a school campus by using a context-aware ubiquitous learning environment called the Handheld English Language Learning Organization (HELLO). HELLO helps students to engage in learning activities based on the ARCS motivation theory, involving various educational strategies, including ubiquitous game-based learning, collaborative learning, and context-aware learning. Two groups of students participated in the learning activities prescribed in a curriculum by separately using ubiquitous game-based learning and non-gaming learning. The curriculum, entitled ‘My Campus’, included three learning activities, namely ‘Campus Environment’, ‘Campus Life’ and ‘Campus Story’. Participants included high school teachers and juniors. During the experiment, tests, a survey, and interviews were conducted for the students. The evaluation results of the learning outcomes and learning motivation demonstrated that incorporating ubiquitous games into the English learning process could achieve a better learning outcomes and motivation than using non-gaming method. They further revealed a positive relationship between learning outcomes and motivation.  相似文献   
45.
Self-testing is a means to check learning effect. Besides time–space restriction, there are many deficiencies in traditional offline self-testing. With the development of information technology, learners can have self-testing on the Internet. Self-testing on Internet, namely, web-based self-testing, overcomes time–space limitation of traditional offline self-testing, but there are still several disadvantages such as monotony and lack of interaction. In the article, a web-based self-testing system with some features of Web 2.0 is designed and implemented, aiming at overcoming the weaknesses of current online self-testing system. Firstly, taking English self-testing as an example, the framework of the system and functions of its main modules is designed according to theories of social learning and constructivism as well as the idea of Web 2.0 and the characteristics of server-side programming. Secondly, in accordance with the design above, a new system is implemented for English learners primarily by using HTML, JavaScript, PHP, and MySQL comprehensively. The role and duty of webmaster are also described briefly. To test the system, some English learners were invited randomly to use it, and feedback information was collected from them after a period of time. It is shown by feedbacks that most learners are satisfied with the system, and the system is of distinct features and favorable practicality compared with other systems, but it still needs to be improved in the design of user interface and some other details. Results in the article demonstrate that the new system can overcome the shortcomings of current systems to some extent.  相似文献   
46.
The authors of the articles in this special issue of Computers in Human Behavior explore the nature of support in gStudy, a computer-supported collaborative learning (CSCL) environment, especially from the perspective of the theory of self-regulation [e.g., Zimmerman, B. J. (2000). Attainment of self-regulation: A social cognitive perspective. In M. Boekaerts, P. Pintrich, & M. Zeidner (Eds.), Handbook of self-regulation, research and applications (pp. 13–39). Orlando, FL: Academic Press]. To comment critically on the systematic and comprehensive research this collection of articles represents is a daunting task. Therefore, I want to begin by insuring that the reader has the appropriate impression of the quality and importance of the collection of studies and the tool itself.  相似文献   
47.
Recently, cooperative communication mechanism is shown to be a promising technology to improve the transmit diversity only by a single transceiver antenna. Using this communication paradigm, multiple source nodes are able to coordinate their transmissions so as to obtain energy savings. As data aggregation is one of the most important operations in wireless sensor networks, this paper studies the energy-efficient data aggregation problem through cooperative communication. We first define the cooperative data aggregation (CDA) problem, and formally prove that this problem is NP-Hard. Due to the difficult nature of this problem, we propose a heuristic algorithm MCT for cooperative data aggregation. The theoretical analysis shows that this algorithm can reach the approximate performance ratio of 2. Moreover, the distributed implementation DMCT of the algorithm is also described. We prove that both centralized and distributed algorithms can construct the same topology for cooperative data aggregation. The experimental simulations show that the proposed algorithms will decrease the power consumption by about 12.5% and 66.3% compared with PEDAP and PEGASIS algorithms respectively.  相似文献   
48.
As research in Computer-Supported Collaborative Learning (CSCL) expands its understanding of joint knowledge building, new perspectives on how social reality is constructed become necessary. Our research concentrates on the longitudinal or diachronic trajectories of Virtual Math Teams (VMT) at The Math Forum, an online community supporting mathematical inquiry. We investigate how these virtual teams constitute themselves while engaged in building collaborative knowledge. We describe as well, through the lens of positioning theory, the interactional activities that allow participants to situate themselves, others, and their collective knowledge resources over time. Our analysis suggests that positioning work is central to constructing a sustained problem space and illustrates how the configurations of positions and resources that co-participants put forward through interaction might change across a team’s trajectory. These changes constitute and are sensitive to the participants’ evolving reasoning routines and other forms of joint participation uniquely related knowledge building. In addition, we show that the VMT activity system affords participants a level of disciplinary engagement which is partly illustrated by active engagement in positioning work. Finally, we suggest that an interactional approach to roles and participation provides a fruitful framework for researchers, designers, and practitioners interested in understanding and creating engaging CSCL interactions.  相似文献   
49.
陈旺  史彦军  滕弘飞 《计算机工程》2011,37(14):134-136
针对大规模资源受限项目调度问题计算复杂的特点,提出一种合作式协同进化分布估计算法(CCEDA)。将合作式协同进化框架与分布估计算法相结合,将复杂问题分解为子问题,利用改进的分布估计算法对每个子问题进行协同优化求解。为提高分布估计算法的局部搜索能力,给出一种对解进行局部搜索的方法。将CCEDA用于求解标准问题库PSPLIB,并与GAPS、GA-DBH、GA-hybrid与GA-FBI算法进行比较,结果证明CCEDA拥有更好的求解性能。  相似文献   
50.
Learning and knowledge building have become critical competences for people in the knowledge society era. In this paper, we propose a sociolinguistic dialogue model for understanding how learning evolves and how cognitive process is constructed in on-line discussions. The knowledge extracted from this model is used to assess participation behavior, knowledge building and performance. The ultimate purpose is to provide effective feedback, evaluation and monitoring to the discussion process. Seven hundred students from the Open University of Catalonia in Spain participated in this study. Results showed that learning and knowledge building may be greatly enhanced by presenting selected knowledge to learners as for their particular skills exhibited during interaction. In addition, this valuable provision of information is used as a meta cognitive tool for tutors and moderators for monitoring and evaluating the discussion process more conveniently. This contribution presents our conceptual model for interaction management as well as key design guidelines and evaluation results. Implications of this study are remarked and further research directions are proposed.  相似文献   
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