全文获取类型
收费全文 | 24960篇 |
免费 | 438篇 |
国内免费 | 16篇 |
专业分类
教育 | 17740篇 |
科学研究 | 2163篇 |
各国文化 | 270篇 |
体育 | 2111篇 |
综合类 | 14篇 |
文化理论 | 189篇 |
信息传播 | 2927篇 |
出版年
2022年 | 187篇 |
2021年 | 289篇 |
2020年 | 433篇 |
2019年 | 722篇 |
2018年 | 938篇 |
2017年 | 926篇 |
2016年 | 797篇 |
2015年 | 484篇 |
2014年 | 739篇 |
2013年 | 4878篇 |
2012年 | 699篇 |
2011年 | 705篇 |
2010年 | 532篇 |
2009年 | 547篇 |
2008年 | 605篇 |
2007年 | 539篇 |
2006年 | 480篇 |
2005年 | 460篇 |
2004年 | 408篇 |
2003年 | 398篇 |
2002年 | 372篇 |
2001年 | 505篇 |
2000年 | 414篇 |
1999年 | 382篇 |
1998年 | 237篇 |
1997年 | 229篇 |
1996年 | 253篇 |
1995年 | 254篇 |
1994年 | 196篇 |
1993年 | 218篇 |
1992年 | 333篇 |
1991年 | 315篇 |
1990年 | 319篇 |
1989年 | 318篇 |
1988年 | 261篇 |
1987年 | 308篇 |
1986年 | 269篇 |
1985年 | 311篇 |
1984年 | 258篇 |
1983年 | 225篇 |
1982年 | 196篇 |
1981年 | 170篇 |
1980年 | 162篇 |
1979年 | 259篇 |
1978年 | 185篇 |
1977年 | 173篇 |
1976年 | 157篇 |
1975年 | 143篇 |
1974年 | 152篇 |
1971年 | 141篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
21.
As a part of efforts to evaluate and monitor the increasing public investment in early childhood education, teachers are being asked to assess children's school readiness. In this study, preschool teachers and kindergarten teachers rated children's skills in three areas (kindergarten readiness, academic skills, and communication skills), and these ratings were compared with direct assessments of the children's skills. Ratings by both groups of teachers tended to be more highly related to basic skills, such as counting and number naming, than to abilities such as solving applied problems and using expressive and receptive vocabulary. Preschool teachers' ratings had a lower association with children's observed skills and abilities than kindergarten teachers' ratings. Ratings of children attending Head Start were systematically inflated, but this relationship was mediated to a significant extent by the teachers' levels of education. More educated teachers rated children in a manner consistent with the children's directly assessed skills. Implications of these findings for informing future efforts to assess school readiness by using teacher ratings are discussed. 相似文献
22.
Objective: To determine whether information retrieval might be enhanced by making each component of a structured abstract a separately searchable field. Design: Parallel searches on records arranged so that each abstract could either be searched in its entirety or as a collection of structured fields. Subjects: Records about cardiovascular disease downloaded from MEDLINE and tested against clinical questions derived from a concurrent survey of CD-ROM use in three health science libraries. Intervention: The investigators identified terms used to structure abstracts on MEDLINE and imported the abstracts into an Idealist database prior to searching using keywords from clinical questions. Measurements and main results: recall and precision rates are given for each question in the ‘structured’ and the ‘unstructured’ set of records. Conclusions: Use of structured, rather than unstructured, abstracts improves precision at the ex-pense of recall and places heavier demands upon the searcher’s skill in choosing the correct fields within the abstract to search. Further investigation requires more accurate simulation of MEDLINE software that utilizes features such as MeSH terms, explode, facilities and delimiters. 相似文献
23.
Wendy M. Yen 《Educational Measurement》1997,16(3):5-15
How accurate is the reported percent of students’reaching standards at the school level? How are standard errors for these statistics computed? How do estimates vary with choice of generalizability model? 相似文献
24.
John M. Budd 《Publishing Research Quarterly》1991,7(2):27-37
In recent years university presses have undergone some significant changes, such as expansion of their scope to include materials
that may have appeal beyond the scholarly market. This article investigates, through the use of a survey of university libraries,
the acquisition of university press products by libraries. In general, recent years have been changes in the relationship
between university presses and libraries that have resulted in fewer items being purchased by the libraries. 相似文献
25.
26.
27.
This article reviews the literature pertaining to the written composing ability of students with learning disabilities that was published primarily in the decade from 1980 to 1990. The papers included are either reports of research or discussions of instructional procedures that are based on research. The topics addressed include story composition, expository writing, training/intervention research, and rationales/procedures for instruction. 相似文献
28.
29.
30.