全文获取类型
收费全文 | 3724篇 |
免费 | 38篇 |
专业分类
教育 | 2608篇 |
科学研究 | 312篇 |
各国文化 | 56篇 |
体育 | 340篇 |
综合类 | 2篇 |
文化理论 | 50篇 |
信息传播 | 394篇 |
出版年
2022年 | 19篇 |
2021年 | 37篇 |
2020年 | 70篇 |
2019年 | 106篇 |
2018年 | 120篇 |
2017年 | 111篇 |
2016年 | 94篇 |
2015年 | 63篇 |
2014年 | 110篇 |
2013年 | 849篇 |
2012年 | 85篇 |
2011年 | 94篇 |
2010年 | 76篇 |
2009年 | 77篇 |
2008年 | 79篇 |
2007年 | 74篇 |
2006年 | 92篇 |
2005年 | 81篇 |
2004年 | 73篇 |
2003年 | 72篇 |
2002年 | 56篇 |
2001年 | 49篇 |
2000年 | 56篇 |
1999年 | 51篇 |
1998年 | 55篇 |
1997年 | 46篇 |
1996年 | 40篇 |
1995年 | 35篇 |
1994年 | 34篇 |
1993年 | 39篇 |
1992年 | 32篇 |
1991年 | 38篇 |
1990年 | 42篇 |
1989年 | 42篇 |
1988年 | 45篇 |
1987年 | 43篇 |
1986年 | 35篇 |
1985年 | 32篇 |
1984年 | 36篇 |
1983年 | 43篇 |
1982年 | 30篇 |
1981年 | 21篇 |
1980年 | 26篇 |
1979年 | 42篇 |
1978年 | 37篇 |
1977年 | 29篇 |
1976年 | 32篇 |
1974年 | 24篇 |
1973年 | 26篇 |
1969年 | 19篇 |
排序方式: 共有3762条查询结果,搜索用时 15 毫秒
991.
Objective:There are no existing validated search filters for the group of 37 Organisation for Economic Co-operation and Development (OECD) countries. This study describes how information specialists from the United Kingdom''s National Institute for Health and Care Excellence (NICE) developed and evaluated novel OECD countries’ geographic search filters for MEDLINE and Embase (Ovid) to improve literature search effectiveness for evidence about OECD countries.Methods:We created the draft filters using an alternative approach to standard filter construction. They are composed entirely of geographic subject headings and are designed to retain OECD country evidence by excluding non-OECD country evidence using the NOT Boolean operator. To evaluate the draft filters’ effectiveness, we used MEDLINE and Embase literature searches for three NICE guidelines that retrieved >5,000 search results. A 10% sample of the excluded references was screened to check that OECD country evidence was not inadvertently excluded.Results:The draft MEDLINE filter reduced results for each NICE guideline by 9.5% to 12.9%. In Embase, search results were reduced by 10.7% to 14%. Of the sample references, 7 of 910 (0.8%) were excluded inadvertently. These references were from a guideline about looked-after minors that concerns both OECD and non-OECD countries.Conclusion:The draft filters look promising—they reduced search result volumes while retaining most OECD country evidence from MEDLINE and Embase. However, we advise caution when using them in topics about both non-OECD and OECD countries. We have created final versions of the search filters and will validate them in a future study. 相似文献
992.
Service bundles, in the context of e-government, are used to group services together that relate to a certain citizen need. These bundles can then be presented on a governmental one-stop portal to structure the available service offerings according to citizen expectations. In order to ensure that citizens utilise the one-stop portal and comprised service bundles for future transactions, the quality of these service bundles needs to be managed and maximised accordingly. Consequently, models and tools that focus on assessing service bundle quality play an important role, when it comes to increasing or retaining usage behaviour of citizens. This study focuses on providing a rigorous and structured literature review of e-government outlets with regard to their coverage of service bundle quality and e-service quality themes. The study contributes to academia and practice by providing a framework that allows structuring and classifying existing studies relevant for the assessment of quality for government portals. Furthermore, this study provides insights into the status quo of quality models that can be used by governments to assess the quality of their service bundles. Directions for future research and limitations of the present study are provided as well. 相似文献
993.
Thomas Snyder 《大学生》2014,(11):70-70
三届数独世界冠军托马斯聿德(ThomasSnyder)为《大学生》读者们专门设计数独题。辛德曾三次获得数独世界冠军,五次夺得美国数独冠军,他的专业是化学,本科毕业于加州理工学院,在哈佛大学取得博士学位,现是斯坦福大学生物工程学助理研究员。 相似文献
994.
Gerry M. Swan Thomas R. Guskey Lee Ann Jung 《Educational Assessment, Evaluation and Accountability》2014,26(3):289-299
The purpose of this study was to determine parents’ and teachers’ perceptions of standards-based and traditional report cards. Participants included 115 parents/guardians of students from a single, midsize school district that had implemented a standards-based report card. During the first two marking periods, all parents/guardians received both a traditional report card in which teachers assigned a single overall grade for each subject and a standards-based report card that included marks for individual standards within subjects. After midyear, parents were asked to complete a survey that asked which form they preferred and the reasons for their preference. Three hundred and eighty three teachers from two nearby midsize school districts considering the adoption of the same standards-based report card completed a similar survey. Parents overwhelmingly preferred the standards-based form. The teachers considering the adoption of a standards based report card were positive overall, but significantly less than the parents who had received them. 相似文献
995.
996.
Thomas D. Wolkow Lisa T. Durrenberger Michael A. Maynard Kylie K. Harrall Lisa M. Hines 《CBE life sciences education》2014,13(4):724-737
Early research experiences must be made available to all undergraduate students, including those at 2-yr institutions who account for nearly half of America''s college students. We report on barriers unique to 2-yr institutions that preclude the success of an early course-based undergraduate research experience (CURE). Using a randomized study design, we evaluated a CURE in equivalent introductory biology courses at a 4-yr institution and a 2-yr institution within the same geographic region. We found that these student populations developed dramatically different impressions of the experience. Students at the 4-yr institution enjoyed the CURE significantly more than the traditional labs. However, students at the 2-yr institution enjoyed the traditional labs significantly more, even though the CURE successfully produced targeted learning gains. On the basis of course evaluations, we enhanced instructor, student, and support staff training and reevaluated this CURE at a different campus of the same 2-yr institution. This time, the students reported that they enjoyed the research experience significantly more than the traditional labs. We conclude that early research experiences can succeed at 2-yr institutions, provided that a comprehensive implementation strategy targeting instructor, student, and support staff training is in place. 相似文献
997.
Andrew G. Campbell Rachel Skvirsky Henry Wortis Sheila Thomas Ichiro Kawachi Christine Hohmann 《CBE life sciences education》2014,13(4):587-592
This paper summarizes the outcomes of a retreat designed to cultivate interactions between trainees at various training levels and provide them opportunities to share their training perspectives and expectations. Retreat outcomes are used to support the development of better science, technology, engineering, and mathematics training practices by informing the trainers’ perspective. 相似文献
998.
Carrie J. Boyce Chandrani Mishra Kristy L. Halverson Aimée K. Thomas 《Journal of Science Education and Technology》2014,23(6):815-826
Informal environments provide students with unique experiences that allow them to actively participate in activities while promoting a positive attitude toward and an increased interest in science. One way to enhance informal science experiences is through the integration of mobile technologies. This integration is particularly useful in engaging underrepresented students in learning science. Our informal environmental science program engages underrepresented, fifth-grade students in an informal learning environment supplemented with mobile tablet technology (iPads). The purpose of this study was to explore how fifth-grade students interacted with nature using mobile technology during a nature hike series. Participants included 55 fifth-grade students from two low-income schools. We found that students used the mobile technology to explore nature and stay engaged throughout the hike. The iPads were used as references, data collectors, and engagement tools. Students had an intense desire in returning to the site and responded positively toward interacting with nature. Prior research has indicated that students in this age group are likely to lose interest in science and the incorporation of field-friendly technology that engages students with nature, not technology alone, is a useful tool for keeping students interested in science. 相似文献
999.
1000.