全文获取类型
收费全文 | 287篇 |
免费 | 8篇 |
专业分类
教育 | 196篇 |
科学研究 | 66篇 |
各国文化 | 2篇 |
体育 | 6篇 |
文化理论 | 2篇 |
信息传播 | 23篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 18篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 53篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1988年 | 2篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1979年 | 2篇 |
1973年 | 4篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1964年 | 1篇 |
1951年 | 1篇 |
1925年 | 1篇 |
1923年 | 1篇 |
1922年 | 2篇 |
1920年 | 1篇 |
1899年 | 1篇 |
1897年 | 2篇 |
1850年 | 1篇 |
排序方式: 共有295条查询结果,搜索用时 15 毫秒
281.
Cyanobacteria: A potential biofertilizer for rice 总被引:1,自引:0,他引:1
Application of high input technologies has resulted in significant increase in agricultural productivity. There is, however,
a growing concern about the adverse effects of indiscriminate use of chemical fertilizers on soil productivity and environmental
quality. Cyanobacteria offer an economically attractive and ecologically sound alternative to chemical fertilizers for realizing
the ultimate goal of increased productivity, especially in rice cultivation. In a wetland rice ecosystem, nitrogen fixation
by free living cyanobacteria also significantly supplements soil nitrogen. 相似文献
282.
Because ethnicity is a basis for defining peer crowds in ethnically diverse American high schools, some may question whether crowds foster discrimination and stereotyping or affirm minority youths' positive ties to their ethnic background. Through examination of both self- and peer ratings of crowd affiliation among 2,465 high school youth aged 14–19 years, this study assesses the likelihood that African American, Asian American, Latino, and multiethnic adolescents are associated with ethnically defined crowds. Crowd affiliations are related to friendship patterns among all groups, positive features of ethnic orientation for Asian and Latino youth, but also some aspects of stereotyping and discrimination for Latinos. Results emphasize ethnic diversity in the role that peer crowds play in minority adolescents' social experiences. 相似文献
283.
The purpose of this article is to help teachers become more responsive to the changing needs and contexts of families in their
efforts to establish relationships and encourage family participation. Through this article, the authors describe the changing
landscape of parenting and the stressors experienced by contemporary families. The authors then provide a review of research
that describes strategies that have been successfully employed by teachers of young children to foster increased communication
and family involvement. The article concludes with suggestions to help early childhood professionals change their paradigm
of parent involvement from a school-centric perspective to one that is more family-centric. 相似文献
284.
Joan Herman Ellen Osmundson Yunyun Dai Cathy Ringstaff Michael Timms 《Assessment in Education: Principles, Policy & Practice》2015,22(3):344-367
This exploratory study of elementary school science examines questions central to policy, practice and research on formative assessment: What is the quality of teachers’ content-pedagogical and assessment knowledge? What is the relationship between teacher knowledge and assessment practice? What is the relationship between teacher knowledge, assessment practice and student learning? Drawing on multiple measures, hierarchical linear modelling and path analysis, results suggest that despite weaknesses in teachers’ content-pedagogical and assessment knowledge, teachers’ formative assessment practices are positively related to student learning. Relationships between teachers’ knowledge and assessment practices are mixed. Findings underscore both the potential and challenge of bringing effective formative practice to fruition as well as the need for continued research. 相似文献
285.
In our continuously changing society, a need for updating one’s skills and knowledge puts pressure on safeguarding the labour
market position of low-qualified employees. However, prior research and official statistics show that employees with a lower
level of education tend to participate less in training than highly-educated individuals. This limited participation is associated
with employers offering fewer opportunities to low-qualified employees, but also with the fact that low-qualified employees
themselves might be less willing to participate. In other words, their learning intentions are assumed to be weaker and more
restricted than the learning intentions of highly-educated employees. The article reports on a quantitative survey research
on the learning intentions of 406 low-qualified employees. The results showed that employees who participated in formal job-related
learning activities during the last 5 years had a stronger learning intention than those who did not. Next, the results of
the stepwise regression showed that self-directedness, financial benefits, self-efficacy, and autonomy were significant positive
predictors of the learning intentions of low-qualified employees. Also, the limited number of possibilities or opportunities
to learn was not significant. The results indicated that a learning intention can lead towards the participation in learning
activities, but participation is not merely initiated by offering opportunities for learning. Organisational aspects such
as job autonomy and financial benefits can stimulate the learning intention of an employee. Finally, regarding the socio-demographic
variables, only limited differences were found. In short, employees with no educational qualifications and a full-time contract
had the lowest intention to learn. 相似文献
286.
Concept inventories hold tremendous promise for promoting the rigorous evaluation of teaching methods that might remedy common student misconceptions and promote deep learning. The measurements from concept inventories can be trusted only if the concept inventories are evaluated both by expert feedback and statistical scrutiny (psychometric evaluation). Classical Test Theory and Item Response Theory provide two psychometric frameworks for evaluating the quality of assessment tools. We discuss how these theories can be applied to assessment tools generally and then apply them to the Digital Logic Concept Inventory (DLCI). We demonstrate that the DLCI is sufficiently reliable for research purposes when used in its entirety and as a post-course assessment of students’ conceptual understanding of digital logic. The DLCI can also discriminate between students across a wide range of ability levels, providing the most information about weaker students’ ability levels. 相似文献
287.
Internationally, there has been a policy push for using student data for instruction. Yet, research has noted few examples of actually understanding how this data-use practice takes place. This study presents a case of an instructional data team making sense of student data. The study shares data to show how teachers’ process for using data to inform their instructional choices is an interpretive one. The study also highlights the fact that, to make sense of test data that are often incapable of capturing backstories of students’ work in school, teachers draw upon informal data that they glean from their observations of and interactions with students. The collective data in the heads of teachers emerge through data team discussions. We conclude with implications for policy, professional learning, and teacher development. 相似文献
288.
Justin Durandt Mervin Green Herman Masimla Mike Lambert 《Journal of sports sciences》2018,36(5):477-484
The purpose of this study was to determine whether there are differences between racial groups for body mass, stature and body mass index (BMI) in South African elite U18 rugby players and whether there were significant changes in these measurements between 2002 and 2012. Self-reported body mass and stature were obtained from U18 players (n = 4007) who attended the national tournament during this period. BMI was calculated for each player.White players were 9.8 kg heavier than black players, who were 2.3 kg heavier than coloured players (P < 0.0001). The body mass of all groups increased from 2002 to 2012 (P < 0.0001). White players were 7.0 cm taller than black players who were 0.5 cm taller than coloured players (P < 0.0001). Players’ stature measurements did not change significantly during the study period. The average BMI of white players was 0.9 kg·m?2 greater than black players who were on average 0.7 kg·m?2 greater than coloured players (P < 0.0001). The BMI of all groups changed similarly over the study period. The body mass, stature and BMI of elite under-18 rugby players in South Africa were significantly different between racial groups. This has implications for transforming the game to make it representative of the South African population. 相似文献
289.
Josje van Houwelingen Raf M. Antwerpen Ad P. C. Holten Ernst Jan Grift Jerry Westerweel Herman J. H. Clercx 《Sports Engineering》2018,21(4):419-427
In this paper a video-based method to automatically track instantaneous velocities of a swimmer is presented. Single cameras were used to follow a marker (LED) attached to the body. The method is inspired by particle tracking techniques, traditionally used in the field of fluid dynamics, to measure local velocities of a fluid flow. During the validation experiment, a white LED was attached to the hip of a swimmer together with a speedometer. A swimmer performed four different stroke types. The velocity profiles using LED tracking were captured and showed less noise than the speedometer measurements. Only at times when the marker disappeared above the water surface due to body role in front crawl and backstroke swimming did the LED tracking fail to capture the athlete’s motion. The algorithm was tested in a 2D case with a single LED to illustrate the proof of principle, but should be suitable for implementation in a 3D analysis or multiple LED analysis. 相似文献
290.