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   41779篇
  免费   459篇
  国内免费   21篇
教育   30532篇
科学研究   3632篇
各国文化   340篇
体育   2825篇
综合类   15篇
文化理论   677篇
信息传播   4238篇
  2022年   221篇
  2021年   333篇
  2020年   514篇
  2019年   797篇
  2018年   3112篇
  2017年   3044篇
  2016年   2479篇
  2015年   752篇
  2014年   982篇
  2013年   6179篇
  2012年   1057篇
  2011年   1556篇
  2010年   1485篇
  2009年   1063篇
  2008年   1396篇
  2007年   1793篇
  2006年   678篇
  2005年   956篇
  2004年   951篇
  2003年   882篇
  2002年   624篇
  2001年   603篇
  2000年   526篇
  1999年   464篇
  1998年   303篇
  1997年   320篇
  1996年   349篇
  1995年   349篇
  1994年   285篇
  1993年   285篇
  1992年   423篇
  1991年   404篇
  1990年   394篇
  1989年   385篇
  1988年   331篇
  1987年   365篇
  1986年   329篇
  1985年   373篇
  1984年   304篇
  1983年   282篇
  1982年   257篇
  1981年   236篇
  1980年   226篇
  1979年   326篇
  1978年   231篇
  1977年   211篇
  1976年   204篇
  1975年   182篇
  1974年   185篇
  1971年   166篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
Orthographic knowledge, the general ability to learn, store, and use information about the orthographic form of words (Stanovich & West, 1989), is a crucial skill for supporting literacy. Although the development of first language (L1) orthographic awareness is impacted by the characteristics of a learner’s L1 writing system, relatively little is known about what impact the L1 may have on second language (L2) orthographic awareness. In this study, English language learners from three L1s (French, Hebrew, Mandarin Chinese), plus L1 English speakers, were tested on their English spelling knowledge using a word-pseudohomophone discrimination task. In addition to allowing for the cross-linguistic comparisons, items were designed to examine whether learners had differing performance on pseudohomophones (misspellings) that targeted vowels versus consonants. Consistent with previous research (e.g., McBride-Chang, Bialystok, Cong, & Li, 2004), the L1 Chinese speakers had the highest (L2) accuracy, followed by the L1 Hebrew and the L1 French speakers. The participants from non-alphabetic languages (Hebrew and Chinese) had significantly lower accuracy on items with misspellings involving vowels compared to consonants, and the size of the vowel-consonant accuracy difference varied substantially across L1 groups. The results demonstrate that the characteristics of a learner’s L1 writing system, particularly the existence of vowel and consonant graphemes, impact the development of L2 orthographic knowledge and sensitivity to different types of word misspellings.  相似文献   
912.
913.
To improve the aerodynamic performance of high-speed trains (HSTs) running in the open air, a multi-objective aerodynamic optimization design method for the head shape of a HST is proposed in this paper. A parametric model of the HST was established and seven design variables of the head shape were extracted. Sample points and their exact values of optimization objectives were obtained by an optimal Latin hypercube sampling (opt. LHS) plan and computational fluid dynamic (CFD) simulations, respectively. A Kriging surrogate model was constructed based on the sample points and their optimization objectives. Taking the total aerodynamic drag force and the aerodynamic lift force of the tail coach as the optimization objectives, the multi-objective aerodynamic optimization design was performed based on a non-dominated sorting genetic algorithm-II (NSGA-II) and the Kriging model. After optimization, a series of Pareto-optimal head shapes were obtained. An optimal head shape was selected from the Pareto-optimal head shapes, and the aerodynamic performance of the HST with the optimal head shape was compared with that of the original train in conditions with and without crosswinds. Compared with the original train, the total aerodynamic drag force is reduced by 2.61% and the lift force of the tail coach is reduced by 9.90% in conditions without crosswind. Moreover, the optimal train benefits from lower fluctuations in aerodynamic loads in crosswind conditions.  相似文献   
914.
Abstract

We present a first-hand, longer-term account of one student’s (Christine’s) experiences in and after a mathematics inquiry course. In this course, students actively posed problems, conducted their own mathematical explorations, and wrote journal entries about their experiences. During the course, Christine found that inquiry helped her develop mathematical content knowledge and a deeper understanding of the nature of research. After the course, Christine became a mathematics education faculty member in a mathematics department and reports that the course impacted the way she teaches mathematics. This provides an illustrative case of the potential long-lasting benefits of an inquiry course.  相似文献   
915.
Over the next decade, Baby Boomers will be reaching retirement age in large numbers and the U.S. will be undergoing one of the most significant demographic shifts in its history. This demographic shift has important implications for the role of higher education as a provider of lifelong learning and for the changing composition of postsecondary institutions. Using data from the 2005 National Household Education Survey, the results of this study informs the higher education community about this emerging student market segment as a way to help us better respond to older adults?? demand for formal learning in postsecondary institutions.  相似文献   
916.
Drawing from ethnographic data, this paper explores how African American male teachers working with African American male students performed their pedagogy. This paper highlights how teachers’ understanding of African American males social and educational needs shaped their pedagogical performance. Interestingly however, teachers’ performance was contingent on the diverse ways they imagined African American males should engage within their social and political worlds. These findings suggest then that African American male teachers’ pedagogic performances were both complex and multifaceted.  相似文献   
917.
918.
It is widely recognized that metacognition is an important mediator for successful and high-level learning, especially in higher education. Nevertheless, a majority of higher education students possess insufficient metacognitive knowledge and regulation skills to self-regulate their learning adequately. This study explores the potential of reciprocal peer tutoring to promote both university students’ metacognitive knowledge and their metacognitive regulation skills. The study was conducted in a naturalistic higher education setting, involving 67 students tutoring each other during a complete semester. A multi-method pretest–posttest design was used combining a self-report questionnaire, assessing students’ metacognitive knowledge and their perceived metacognitive skilfulness, with the analysis of think-aloud protocols, revealing students’ actual use of metacognitive strategies. Results indicate no significant pretest to posttest differences in students’ metacognitive knowledge, nor in their perception of metacognitive skill use. In contrast, significant changes are observed in students’ actual metacognitive regulation. At posttest, students demonstrate significantly more frequent and more varied use of metacognitive regulation, especially during the orientation, monitoring, and evaluation phases. Furthermore, our findings point to an increase in more profound and higher-quality strategy use at posttest.  相似文献   
919.
This study, framed by the component model of reading (CMR), examined the relative importance of kindergarten-entry predictors of first grade reading performance. Specifically, elements within the ecological domain included dialect, maternal education, amount of preschool, and home literacy; elements within the psychological domain included teacher-reported academic competence, social skills, and behavior; and elements within the cognitive domain included initial vocabulary, phonological, and morpho-syntactic skills, and alphabetic and word recognition skills. Data were obtained for 224 culturally diverse kindergarteners (58% Black, 34% White, and 8% Hispanic or other; 58% received free or reduced-price lunch) from a larger study conducted in seven predominantly high poverty schools (n = 20 classrooms) in a midsized city school district in northern Florida. Results from a hierarchical multiple regression (with variables in the ecological domain entered first, followed by the psychological and cognitive domains) revealed a model that explained roughly 56% of the variance in first grade reading achievement, using fall-of-kindergarten predictors. Letter-word reading and morpho-syntactic skill were the strongest significant predictors. The findings largely support the CMR model as a means to understand individual differences in reading acquisition and, in turn, to support data-based instructional decisions for a wider range of children.  相似文献   
920.
This article analyses academic work and the academic workforce in the context of current dynamics and likely futures. It discusses the significance of academic work, reviews workforce characteristics, and analyses tensions and pressures. Prevailing conceptualisations, it is argued, do not reflect the current situation in which the profession finds itself, and would provide a very shaky foundation on which to build the future workforce. There is an overarching need for a fresh conceptualisation of academic work that is authentic and feasible and suggestions are offered of what this might look like. A number of strategies are proposed how such a recasting might be implemented. The paper works from Australian research, and make suggestions for other systems.  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