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   11838篇
  免费   7篇
教育   9109篇
科学研究   1240篇
体育   396篇
文化理论   385篇
信息传播   715篇
  2024年   1篇
  2023年   3篇
  2022年   4篇
  2021年   10篇
  2020年   19篇
  2019年   24篇
  2018年   2199篇
  2017年   2092篇
  2016年   1582篇
  2015年   119篇
  2014年   125篇
  2013年   123篇
  2012年   235篇
  2011年   708篇
  2010年   845篇
  2009年   440篇
  2008年   651篇
  2007年   1163篇
  2006年   75篇
  2005年   406篇
  2004年   449篇
  2003年   357篇
  2002年   142篇
  2001年   8篇
  2000年   20篇
  1999年   3篇
  1998年   3篇
  1997年   14篇
  1993年   1篇
  1992年   1篇
  1991年   7篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1970年   1篇
  1969年   1篇
  1964年   1篇
  1963年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
The goal of this study was to define the construct and establish the validity of disciplinary literacy, which has recently gained attention from the implementation of the Common Core State Standards (National Governors Association Center for Best Practices & Council of Chief State School Officers in Common Core State Standards for English language arts & literacy in history/social studies, science, and technical subjects [PDF]. Authors, Washington, DC, 2010). After defining disciplinary literacy in the four core disciplines of English language arts, science, history and social studies, and mathematics, scales were developed and administered to a snowball sample of professionals nationwide, with 857 respondents. The data showed evidence of disciplinary literacy as a multidimensional construct with three related factors: source literacy, analytic literacy, and expressive literacy. Based on EFA and CFA results, we can conclude that there are at least three types of literacy in operation among the four core disciplines. The three factors of literacy varied significantly by the four core disciplines of English/language arts (ELA), science, history and social studies, and mathematics, supporting the notion that each discipline uses literacy uniquely. This is the first study of its kind to attempt to define, quantify, and validate the construct of disciplinary literacy.  相似文献   
162.
Increasingly, individuals navigate their own careers in self-directed (protean) and boundaryless contexts. These concepts have been applied to adult employees but have seen limited application with young adults. Therefore, 205 college students were assessed on the Protean and Boundaryless Career Attitudes scales (Briscoe, Hall, and DeMuth, 2006); i.e., self-directed career management, values-driven, boundaryless mindset, and organizational mobility preferences. Scale items were reworded to focus on college experience. Cluster analysis organized respondents into five distinct protean-boundaryless career types. Three types were similar to those hypothesized for adults, while two types were unique to our sample.  相似文献   
163.
A 3D multi-time scale discrete element method-computational fluid dynamic (DEM-CFD) coupling approach was applied to investigate the filtration of micron-sized particles by different types of fiber arrays. Both the pressure drop and the filtration efficiency were examined to indicate the filtration performance of the fiber arrays. Fibers that were uniformly arrayed in a parallel or staggered manner were compared. Results showed that the staggered array showed a better performance than the parallel array in terms of both pressure drop and filtration efficiency. Further, we compared the performance of different staggered arrays, i.e. a regular case, one densified in the front layers and another densified in the back layers. The front densified array was found to enter the clogging and cake filtration stage in the shortest time, leading to the highest filtration efficiency, but the highest pressure drop. The back densified array still achieved a much higher filtration efficiency, despite a much lower pressure drop comparable to that of the regular array. The results suggest that the two kinds of densified arrays may be suited for different purposes, e.g. baghouse filters or breathing masks.  相似文献   
164.
The pressurized reservoir is a closed hydraulic tank which plays a significant role in enhancing the capabilities of hydraulic driven robotics. The spring pressurized reservoir adopted in this paper requires comprehensive performance, such as weight, size, fluid volume, and pressure, which is hard to balance. A novel interactive multi-objective optimization approach, the feasible space tightening method, is proposed, which is efficient in solving complicated engineering design problems where multiple objectives are determined by multiple design variables. This method provides sufficient information to the designer by visualizing the performance trends within the feasible space as well as its relationship with the design variables. A step towards the final solution could be made by raising the threshold on performance indicators interactively, so that the feasible space is reduced and the remaining solutions are more preferred by the designer. With the help of this new method, the preferred solution of a spring pressurized reservoir is found. Practicability and efficiency are demonstrated in the optimal design process, where the solution is determined within four rounds of interaction between the designer and the optimization program. Tests on the designed prototype show good results.  相似文献   
165.
Misconceptions about climate change science are pervasive among the US public. This study investigated the possibility that these misconceptions may be reflective of science teachers’ knowledge and teaching of climate change science. Florida and Puerto Rico secondary science teachers who claim to teach extensively about climate change were surveyed in regard to their conceptions of climate change science and the climate change-related topics they teach. Results show that many teachers hold naïve views about climate change (e.g. that ozone layer depletion is a primary cause of climate change) and climate change science (e.g. that it must be based on controlled experiments for it to be valid). In addition, teachers in both groups neglect crucial topics such as how evidence for climate change is developed and the social, political, and economic dimensions of climate change. Our results suggest the need for teachers to understand how to teach climate change and the nature of climate change science using authentic contexts that promote effective socioscientific decision-making and climate change mitigation.  相似文献   
166.
Visual signals convey emotions and intentions between individuals. Darwin underlined that human facial expressions represent a shared heritage between our species and many other social mammals. Social play is a fertile field to examine the role and the potential communicative function of facial expressions. The relaxed open-mouth (or play face) is a context-specific playful expression, which is widespread in human and non-human mammals. Here, we focus on playful communication by applying Tinbergen’s four areas of inquiry: proximate causation, ontogeny, function, and evolution. First of all we explore mimicry by focusing on its neural substrates and factors of modulation within playful and non-playful context (proximate causation). Play face is one of the earliest facial expressions to appear and be mimicked in neonates. The motor resonance between infants and their caregivers is essential later in life when individuals begin to engage in increasingly complex social interactions, including play (ontogeny). The success of a playful session can be evaluated by its duration in time. Mirroring facial expressions prolongs the session by favoring individuals to fine-tune their own motor sequences accordingly (function). Finally, through a comparative approach we also demonstrate that the elements constituting play communication and mimicry are sensitive to the quality of interindividual relationships of a species, thus reflecting the nature of its social network and style (evolution). In conclusion, our goal is to integrate Tinbergen’s four areas of ethological inquiry to provide a broader framework regarding the importance of communication and mimicry in the play domain of humans and other social mammals.  相似文献   
167.
168.
The main purpose of this paper is to investigate the intellectual structure of the research on educational technology in science education (ETiSE) within the most recent years (2008–2013). Based on the criteria for educational technology research and the citation threshold for educational co-citation analysis, a total of 137 relevant ETiSE papers were identified from the International Journal of Science Education, the Journal of Research in Science Teaching, Science Education, and the Journal of Science Education and Technology. Then, a series of methodologies were performed to analyze all 137 source documents, including document co-citation analysis, social network analysis, and exploratory factor analysis. As a result, 454 co-citation ties were obtained and then graphically visualized with an undirected network, presenting a global structure of the current ETiSE research network. In addition, four major underlying intellectual subfields within the main component of the ETiSE network were extracted and named as: (1) technology-enhanced science inquiry, (2) simulation and visualization for understanding, (3) technology-enhanced chemistry learning, and (4) game-based science learning. The most influential co-citation pairs and cross-boundary phenomena were then analyzed and visualized in a co-citation network. This is the very first attempt to illuminate the core ideas underlying ETiSE research by integrating the co-citation method, factor analysis, and the networking visualization technique. The findings of this study provide a platform for scholarly discussion of the dissemination and research trends within the current ETiSE literature.  相似文献   
169.
The study reported in this paper concerns the tensions and conflicts that teachers experience while they enact a new set of reform-oriented curricular materials into their classrooms. Our focus is οn the interactions developed in two groups of teachers in two schools for a period of a school year. We use Activity Theory to study emerging contradictions and we elaborate on the construct of dialectical opposition to understand the nature of these contradictions and their potential for teacher learning. We provide evidence that discussions about contradictions and their dialectical character in the two groups support teachers to engage differently in mathematics teaching and learning and carry potentials for shifts in the practices that evolve in their classrooms. Our study addresses empirically in the context of mathematics teaching the philosophical claim about the role of contradictions as a driving force for any dynamic system.  相似文献   
170.
An important issue in the design of secondary-level education is the balance between conveying general and occupation-specific (vocational) skills. On the one hand, vocationally oriented programmes, providing occupation-specific skills with immediate labour market relevance, have repeatedly been shown to secure safe pathways into employment. On the other hand, these programmes tend to put less emphasis on developing general knowledge, skills and competencies, including numeracy and literacy, which are foundational to lifelong learning. Hence, when the needs of the labour market change, employees who opted for a vocational track when they were at secondary school risk being less flexible in adapting to such changes later in their career. The authors of this article examine whether this results in a trade-off between short-term gains and long-term losses by considering differences in the labour market careers of vocationally and generally educated respondents in the 2012 Programme for the International Assessment of Adult Competencies (PIAAC). Their results suggest that early labour market benefits of vocational specialisation decrease over time; the authors relate this to its lower ability to equip secondary school students – future employees – with skills for lifelong learning.  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