全文获取类型
收费全文 | 12373篇 |
免费 | 59篇 |
国内免费 | 6篇 |
专业分类
教育 | 8450篇 |
科学研究 | 1480篇 |
各国文化 | 144篇 |
体育 | 838篇 |
综合类 | 6篇 |
文化理论 | 107篇 |
信息传播 | 1413篇 |
出版年
2021年 | 95篇 |
2020年 | 165篇 |
2019年 | 241篇 |
2018年 | 248篇 |
2017年 | 293篇 |
2016年 | 268篇 |
2015年 | 164篇 |
2014年 | 249篇 |
2013年 | 2412篇 |
2012年 | 219篇 |
2011年 | 214篇 |
2010年 | 173篇 |
2009年 | 191篇 |
2008年 | 243篇 |
2007年 | 234篇 |
2006年 | 209篇 |
2005年 | 175篇 |
2004年 | 172篇 |
2003年 | 152篇 |
2002年 | 141篇 |
2001年 | 151篇 |
2000年 | 185篇 |
1999年 | 172篇 |
1998年 | 103篇 |
1997年 | 107篇 |
1996年 | 120篇 |
1995年 | 107篇 |
1994年 | 128篇 |
1993年 | 133篇 |
1992年 | 167篇 |
1991年 | 170篇 |
1990年 | 171篇 |
1989年 | 172篇 |
1988年 | 136篇 |
1987年 | 151篇 |
1986年 | 157篇 |
1985年 | 180篇 |
1984年 | 174篇 |
1983年 | 172篇 |
1982年 | 135篇 |
1981年 | 147篇 |
1980年 | 121篇 |
1979年 | 158篇 |
1978年 | 162篇 |
1977年 | 111篇 |
1976年 | 114篇 |
1975年 | 108篇 |
1974年 | 91篇 |
1973年 | 106篇 |
1972年 | 94篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
221.
Parker JM Anderson CW Heidemann M Merrill J Merritt B Richmond G Urban-Lurain M 《CBE life sciences education》2012,11(1):47-57
We present a diagnostic question cluster (DQC) that assesses undergraduates' thinking about photosynthesis. This assessment tool is not designed to identify individual misconceptions. Rather, it is focused on students' abilities to apply basic concepts about photosynthesis by reasoning with a coordinated set of practices based on a few scientific principles: conservation of matter, conservation of energy, and the hierarchical nature of biological systems. Data on students' responses to the cluster items and uses of some of the questions in multiple-choice, multiple-true/false, and essay formats are compared. A cross-over study indicates that the multiple-true/false format shows promise as a machine-gradable format that identifies students who have a mixture of accurate and inaccurate ideas. In addition, interviews with students about their choices on three multiple-choice questions reveal the fragility of students' understanding. Collectively, the data show that many undergraduates lack both a basic understanding of the role of photosynthesis in plant metabolism and the ability to reason with scientific principles when learning new content. Implications for instruction are discussed. 相似文献
222.
223.
224.
225.
Thomas P. Reilly Owen W. Drudge James C. Rosen Dorene E. Loew Mariellen Fischer 《Psychology in the schools》1985,22(4):380-382
Twenty-six normal first-grade children (M = 7.0 years) were administered the WISC-R, the McCarthy Scales, and the Woodcock-Johnson Scales of Cognitive Ability. Two years later, their levels of academic achievement were determined by way of the WRAT and global teacher ratings of classroom performance. Pearson intercorrelations among the summary indices of the three intellectual measures were significant and uniformly high (rang. 77-.95). Correlations between first-grade ability scores and third-grade achievement measures also were significant (range .64-.90), suggesting strong predictive validity for each of the cognitive instruments. Though not significantly so, the correlations between the Woodcock-Johnson and achievement tended to be the highest. The results indicate that all three intellectual measures are appropriate for predicting later academic achievement in young school-aged children. 相似文献
226.
227.
To many who develop and use free software, the GNU General Public License represents an embodiment of the meaning of free
software. In this paper we examine the definition and meaning of free software in the context of three events surrounding
the GNU General Public License. We use a case involving the GPU software project to establish the importance of Freedom 0
in the meaning of free software. We analyze version 3 of the GNU General Public License and conclude that although a credible
case can be made that the added restrictions are consistent with the definition of free software, the case requires subtle
arguments. Strong arguments against the added restrictions are less subtle, and may therefore be more convincing to many users
and developers. We also analyze the Affero General Public License and conclude that it is inconsistent with the definition
of free software. 相似文献
228.
College and university planning in an era of contraction 总被引:1,自引:0,他引:1
Anthony W. Morgan 《Higher Education》1982,11(5):553-566
Drawing from published case studies of U.S. institutions and from case studies conducted in the U.K., the author assesses the causes and characteristics of decline among institutions of higher education and the various types of institutional planning responses. Planning under conditions of instability and decline is held to be significantly different from planning under conditions of growth in that the politics of planning are more intensive and highly defensive. Changes in the standards for organizational consensus in planning under decline are also discussed. The problems and advantages inherent in developing strategic contingency plans as opposed to developing strategic planning policies are noted.The author concludes with a summarization of the contrasting planning styles characteristic of U.S. institutions, U.K. polytechnics and U.K. universities, noting that the model and success of recent University Grants Committee selective cuts among many institutions is more likely to be transferred to the polytechnic sector than across the Atlantic to U.S. institutions. 相似文献
229.
230.