全文获取类型
收费全文 | 593篇 |
免费 | 8篇 |
专业分类
教育 | 452篇 |
科学研究 | 12篇 |
各国文化 | 7篇 |
体育 | 49篇 |
信息传播 | 81篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2020年 | 11篇 |
2019年 | 14篇 |
2018年 | 15篇 |
2017年 | 27篇 |
2016年 | 29篇 |
2015年 | 10篇 |
2014年 | 20篇 |
2013年 | 170篇 |
2012年 | 14篇 |
2011年 | 11篇 |
2010年 | 19篇 |
2009年 | 21篇 |
2008年 | 14篇 |
2007年 | 19篇 |
2006年 | 19篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有601条查询结果,搜索用时 15 毫秒
131.
How do pre-kindergarteners spend their time? Gender,ethnicity, and income as predictors of experiences in pre-kindergarten classrooms 总被引:2,自引:0,他引:2
Diane M. Early Iheoma U. Iruka Sharon Ritchie Oscar A. Barbarin Donna-Marie C. Winn Gisele M. Crawford Pamela M. Frome Richard M. Clifford Margaret Burchinal Carollee Howes Donna M. Bryant Robert C. Pianta 《Early childhood research quarterly》2010
The current paper considers how children spend their time in state-funded pre-kindergarten programs and how time use relates to ethnicity, gender, and family income, based on the assumption that how time is spent in pre-kindergarten is relevant for the programs’ success in narrowing achievement gaps. Classroom observations of 2061 children in 652 pre-k programs in 11 states were analyzed. Findings indicated that the pre-kindergarten day was roughly equally divided among free choice, teacher-assigned activities, and meals/routines. Children spent much of their time in language/literacy, social studies, and art, and less time in math and gross motor activities. Much of the pre-k day was spent in ‘no coded learning activity.’ Children in classes with lower proportions of Latino and African American children and higher average income-to-need ratios were generally engaged in richer and more stimulating experiences. The child-level variables of ethnicity and income were generally unrelated to how children spent their time, above and beyond the effects of classroom-level ethnicity and income. There were generally small, but significant gender differences – always in the gender-stereotyped direction – in how time was spent, especially during free choice time. 相似文献
132.
134.
135.
136.
137.
Scaling Up the TREC Collection 总被引:3,自引:3,他引:0
Due to the popularity of Web search engines, a large proportion of real text retrieval queries are now processed over collections measured in tens or hundreds of gigabytes. A new Very Large test Collection (VLC) has been created to support qualification, measurement and comparison of systems operating at this level and to permit the study of the properties of very large collections. The VLC is an extension of the well-known TREC collection and has been distributed under the same conditions. A simple set of efficiency and effectiveness measures have been defined to encourage comparability of reporting. The 20 gigabyte first-edition of the VLC and a representative 10% sample have been used in a special interest track of the 1997 Text Retrieval Conference (TREC-6). The unaffordable cost of obtaining complete relevance assessments over collections of this scale is avoided by concentrating on early precision and relying on the core TREC collection to support detailed effectiveness studies. Results obtained by TREC-6 VLC track participants are presented here. All groups observed a significant increase in early precision as collection size increased. Explanatory hypotheses are advanced for future empirical testing. A 100 gigabyte second edition VLC (VLC2) has recently been compiled and distributed for use in TREC-7 in 1998. 相似文献
138.
By adolescence, men's participation and achievement in science exceeds women's. This article reports a case study that examined the beginnings of this gender differentiation during a naturally occurring academic activity that was designed to support and guide young children's interest in doing science. Data were collected during 2 successive years of a science fair for children in Grades 1–6 of a progressive private school. A total of 268 projects were characterized in terms of achievement and area of science. Parents provided information about the way children selected and created projects. In both years and in all grade levels, boys tended to choose to work in the physical sciences, and girls in the biological and social sciences. Peer collaborations were exclusively same sex. Achievement and parental involvement were not gender related. Factors are discussed that might lead to an early divergence of boys' and girls' interests in science within a context that promotes its exploration. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 845–857, 1998. 相似文献
139.
140.