排序方式： 共有50条查询结果，搜索用时 15 毫秒
41.
Kinetics of Thermal‐Degradation of Betanins: A Teaching Mini‐Project for Undergraduates Employing the Red Beet 
下载免费PDF全文
下载免费PDF全文 Clarissa H. Rosa Francine Antelo Gilber R. Rosa 《Journal of Food Science Education》2018,17(4):104-110
A 4‐week mini‐project is proposed for an experimental Physical Chemistry course applied in Food Science training. Activities include preparation of beet extract for the extraction of betanins and analysis of the kinetics of betanins in thermal degradation at three temperatures (60, 70, and 80 ºC). In addition to developing common laboratory routines (for example, dilution and use of the UV‐Vis spectrophotometer), students will have contact with the usual procedure for evaluating use of natural dyes in the food industry. 相似文献
42.
43.
Understanding student engagement in online learning environments: the role of reflexivity 总被引：1，自引：0，他引：1
Peter Kahn Lucy Everington Kathleen Kelm Iain Reid Francine Watkins 《Educational technology research and development : ETR & D》2017,65(1):203-218
It is important to develop understanding of what underpins the engagement of students in online learning environments. This article reports on a multiple case study that explored student engagement in a set of postgraduate degrees offered on a fully online basis. The study was based on a theorization of student engagement as the exercise of intentional human action, .or agency. It identified ways in which tasks and social relations in the online learning environments triggered reflexivity on the part of students, with ‘reflexivity’ understood to mean the ordinary mental capacity to consider oneself in relation to one’s social setting. A different relationship between reflexivity and student engagement was in view than that identified by Margaret Archer with regard to reflexivity and social mobility. Rather than displaying one dominant mode of reflexivity, the students considered in the study were seen to draw on a range of modes. The engagement of these students in their learning was also seen to depend on the manner in which they engaged in reflexivity centred on the pursuit of shared goals, that is in collective reflexivity. Specific practices were seen to trigger constructive forms of collective reflexivity, while fractured and restricted forms of collective reflexivity were linked to student disengagement in relation to joint tasks. As well as adverting to the importance of collective reflexivity to learning, the study highlights scope for dissonance between the modes of reflexivity and practices favoured by an online learning environment and the reflexive profile of the student. 相似文献
44.
OBJECTIVE: Various experiences with violence during childhood and adolescence (parental violence, exposure to marital violence, sexual abuse within and outside the family, sexual harassment at school, community violence, involvement with violent or victimized peers, and previous dating violence) are examined as potential risk factors for psychological, physical, and sexual revictimization in adolescent girls' dating relationships. METHOD: A group of 917 teenage girls (mean age = 16.3) were recruited in 5 high schools located in low to middle socioeconomic areas. Participants were in the 10th and 11th grades, and each completed a self-administered questionnaire. Analyses were performed on the 622 participants who reported having at least one dating partner in the last 12 months. RESULTS: Prevalence rates for past victimization experiences varied from 13% to 43%. Regarding last-year dating victimization, prevalence rates varied from 25% to 37%, depending on the type of violence sustained. Results suggest that extrafamilial experiences with violence are stronger risk factors for recent dating victimization than intrafamilial experiences, especially being sexually harassed by male peers at school and being involved with violent or victimized peers during the year preceding the survey. However, it is important to differentiate between girls who are repeatedly victims of violence in a single, long-term relationship (repeat dating victimization), and girls who are revictimized by different partners (dating revictimization), the former sustaining more frequent physical and psychological violence than the latter. CONCLUSIONS: Findings underline the importance of early prevention of adolescent dating violence. Prevention programs should especially address extrafamilial experiences with violence as important risk factors for victimization in dating relationships, and teach girls strategies to break up abusive relationships. 相似文献
45.
46.
Erik F. Strommen Francine S. Frome 《Educational technology research and development : ETR & D》1993,41(1):5-16
The present study examined the effectiveness of one configuration of automatic speech recognition (ASR) software and hardware with a child sample of 36 three-year-olds and a comparison sample of 20 adults. Subjects used a speaker-dependent, template-based system to play a simple Sesame Street naming game. Results indicated that while the system performed well with adults, it was much less effective with children. An analysis of the children's performances indicates that children's speech is more variable, in both volume and content, than that of adults. The ASR system responded ineffectively to this variability, resulting in inferior performance. Specific behaviors and their effects on the ASR system are identified, and possible system modifications that address these behaviors are noted. 相似文献
47.
48.
49.
50.