全文获取类型
收费全文 | 20708篇 |
免费 | 78篇 |
国内免费 | 9篇 |
专业分类
教育 | 15052篇 |
科学研究 | 2294篇 |
各国文化 | 58篇 |
体育 | 1017篇 |
综合类 | 3篇 |
文化理论 | 447篇 |
信息传播 | 1924篇 |
出版年
2022年 | 56篇 |
2021年 | 108篇 |
2020年 | 144篇 |
2019年 | 208篇 |
2018年 | 2503篇 |
2017年 | 2381篇 |
2016年 | 1885篇 |
2015年 | 307篇 |
2014年 | 397篇 |
2013年 | 1555篇 |
2012年 | 459篇 |
2011年 | 1009篇 |
2010年 | 1070篇 |
2009年 | 635篇 |
2008年 | 876篇 |
2007年 | 1357篇 |
2006年 | 243篇 |
2005年 | 548篇 |
2004年 | 634篇 |
2003年 | 495篇 |
2002年 | 263篇 |
2001年 | 204篇 |
2000年 | 217篇 |
1999年 | 183篇 |
1998年 | 101篇 |
1997年 | 144篇 |
1996年 | 111篇 |
1995年 | 77篇 |
1994年 | 98篇 |
1993年 | 72篇 |
1992年 | 168篇 |
1991年 | 137篇 |
1990年 | 122篇 |
1989年 | 145篇 |
1988年 | 129篇 |
1987年 | 102篇 |
1986年 | 108篇 |
1985年 | 111篇 |
1984年 | 80篇 |
1983年 | 95篇 |
1982年 | 65篇 |
1981年 | 72篇 |
1980年 | 64篇 |
1979年 | 105篇 |
1978年 | 66篇 |
1977年 | 68篇 |
1976年 | 56篇 |
1975年 | 51篇 |
1974年 | 61篇 |
1973年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
The present study examined characteristics of students who took advantage of the opportunity to learn Algebra II from a highly skilled teacher. In particular, student information was gathered concerning: (a) the amount of mathematics students knew prior to the class, (b) their motivation for learning mathematics, (c) the number and types of interactions they had with the teacher during class, (d) degree of self-regulation, and (e) general aptitude. A model for achievement was used that suggests both opportunity and propensity are important (i.e., students must be willing and able to take advantage of opportunity). Support for the model was found. Propensity to take advantage of a highly favorable opportunity accounted for almost sixty percent of the variance in achievement. In particular, students who were self-regulated, had strong mathematics backgrounds, and had low levels of frustration benefited more from high-quality instruction. 相似文献
152.
Visual cues have an important role in food preference for both rats and humans. Here, we aim to isolate the effects of numerosity, density, and surface area on food preference and running speed in rats, by using a forced-choice maze paradigm. In Experiment 1, rats preferred and ran faster for a group of multiple smaller pellets rather than a single large pellet, corroborating previous research (Capaldi, Miller, & Alptekin Journal of Experimental Psychology: Animal Behavior Processes, 15(1), 75–80, 1989). Further experiments tested the prevailing hypothesis that multiple food pieces are more reinforcing because they occupy a larger surface area. Experiment 2 controlled for numerosity by utilizing a continuous food: mashed potatoes flattened to cover a larger surface area or rounded into a ball. The rats preferred and ran faster for the flattened potatoes, suggesting surface area plays a role in quantity estimations. Finally, in Experiment 3, rats displayed no preference or difference in running speed between a group of scattered and clustered pellets when number of pellets were kept constant. Taken together, these results suggest that density has an important role in food perception—that is, the rewarding effect of higher numerosity or larger surface area is removed when the food does not fill out the entire space. Alternative explanations and implications for human diet are discussed. 相似文献
153.
Using Variables in School Mathematics: Do School Mathematics Curricula Provide Support for Teachers?
James Dogbey 《International Journal of Science and Mathematics Education》2016,14(6):1175-1196
This study employed content analysis to examine 3 popular middle-grades mathematics curricula in the USA on the support they provide for teachers to implement concepts associated with variables in school mathematics. The results indicate that each of the 3 curricula provides some type of support for teachers, but in a varied amount and quality. More specifically, whereas the University of Chicago School Mathematics Project (UCSMP) curriculum provides support for teachers on several aspects of using variables in school mathematics, the support found in the Connected Mathematics 2 and the Math Connects curricula focused mainly on one conception of variables—namely, the use of variables as quantity that varies in the Connected Mathematics 2 curriculum and the use of variables as specific unknowns in the Math Connects curriculum. Overall, the UCSMP curriculum provides the most support for teachers, followed by the Connected Mathematics 2 curriculum, with the Math Connects curriculum recording the least support for teachers to enact variable concepts. It is worth pointing out that, although the 3 curricula collectively provide guidance for teachers to implement variable ideas within meaningful real-world contexts, the supports identified in the respective curriculum were not sufficient in addressing all of the areas that are essential for teaching the many concepts associated with variables in school mathematics effectively. Recommendations for curriculum developers and for international researchers with interest in the roles of variables in school mathematics are provided. 相似文献
154.
155.
Yiu-yin Lee 《浙江大学学报(A卷英文版)》2017,18(1):75-82
This paper addresses the effect of leakage on the natural frequencies of a large amplitude vibrating panel backed by a cavity, which has not been considered in many other related studies. The structural-acoustic governing equations are employed to study this nonlinear problem. An elliptical integral method, which was recently developed for the nonlinear panel cavity problem, is introduced here to solve for the structural-acoustics responses. The present results agree reasonably well with those obtained from the classical harmonic balance method. Modal convergences of the nonlinear solutions are performed to verify the proposed method. The effects of vibration amplitude and leakage size are studied and discussed. It is found that (1) the edge leakages in a panel cavity system significantly affect the natural frequency properties, and (2) the edge leakages induce a low frequency acoustic resonance. 相似文献
156.
In this paper, we discuss methodological issues that emerged as we worked through a small empirical research project, ‘Engaging Aboriginal students in education through community empowerment’. Recent national policy statements (see, for example, MCEETYA 2000, NBEET 1995) argue the importance of education/research that keeps the locus of control within the Aboriginal community as a means to further the goal of self-determination and improve educational outcomes. In keeping with these recommendations, our project aimed to challenge assimilationist frameworks and sought to ‘empower’ members of the local Aboriginal community through participation in the project. 相似文献
157.
158.
Bodong Chen 《Educational technology research and development : ETR & D》2017,65(2):255-277
The evaluation of promisingness is central to knowledge building and knowledge creation but remains largely unexplored. As part of a design-based research program to support promisingness judgments, the present study implemented an intervention in a sixth grade science class, with the goal of exploring the potential of promisingness judgments to foster scientific understanding and epistemic beliefs. Aided by a Promising Ideas Tool and pedagogical supports designed for this intervention, students explored the concept of promisingness, judged the promisingness of their community ideas, and engaged in iterative cycles of idea refinement. Results indicated that students were capable of improving their understanding of promisingness and making promisingness judgments deemed sensible by domain experts. The conceptual understanding and epistemic beliefs displayed by students improved over the course of the intervention, and such improvement happened in tandem with students’ understanding of promisingness. The implications of this exploratory study and future research are discussed. 相似文献
159.
160.