Simple operated multipurpose temperature control cryostat     

ABBAS T.A. OMAR M.S. 《浙江大学学报(A卷英文版)》2007,8(5):793-796

A suitable simple optical cryostat for optical, magneto-optical, electrical and thermo-electrical measurements was designed. It is suitable for use in a magnetic pool gap as narrow as less than 1 cm. Throughout a long period of time, the heat diffusion process of the cryostat can be easily operated at slow increase in sample temperature in a range 1.25 K/min at 200 K that will be reduced gradually to 0.66 K at room temperature. Liquid nitrogen was used to cool down the temperature. During the operation, the change in the measured energy gap of a semiconductor sample and other physical parameters resulting from the change of temperature can be corrected through the temperature coefficient of that parameter at the corresponding temperature. The cryostat was successfully used for all experiments mentioned above to measure the properties of a single crystal of GaP (Gallium Phosphate) semiconductor.  相似文献   

Higher education decisions in Peru: on the role of financial constraints,skills, and family background     

Juan F. Castro  Gustavo Yamada  Omar Arias 《Higher Education》2016,72(4):457-486

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Quadrupole ion traps     

Pushpa M. Rao  Richard D’Souza  S. A. Ahmad 《Resonance》2001,6(4):22-37

During the last two decades there has been tremendous progress in the technique of trapping and cooling ions using quadrupole ion traps. Using these trapping techniques one can have charged particles of a single species confined near the trap centre, which enables to carry out studies of these ions in a well-controlled environment. The long storage times of the ions, possible in these traps, results in the elimination of transit-time broadening making it possible to do precision spectroscopic measurements on these ions. Several important experiments with single electron or ion have been undertaken to address problems related to basic physics, such as the measurement of the electron radius, precision measurements of fundamental parameters and tests of the predictions of quantum mechanics.  相似文献   

Teaching and learning about science practices: insights and challenges in professional development     

Ahmad Qablan 《Teacher Development》2016,20(1):76-91

The purpose of this study was to determine if science teachers showed a change in their ability to design and implement science lessons that integrate twenty-first century science practices as a result of their participation in a subject-specific professional development program. A qualitative design utilizing inductive analysis was used to investigate teachers’ ability to design inquiry-oriented lessons and implement them in the classroom. Eight science teachers participated in the study. Findings showed that teachers have benefited from their participation in the program and were able to plan and implement their inquiry-oriented lesson plans and implement them in the classroom. The analysis also showed that teachers were not able to demonstrate their ability in two dimensions of inquiry (asking scientifically oriented questions and designing and carrying out investigations). Finally, several suggestions were presented to modify the program’s training materials to focus more on these two dimensions of inquiry.  相似文献   

Modern Traditions? British Muslim Women and Academic Achievement     

Fauzia Ahmad 《Gender and education》2001,13(2):137-152

Participation rates in higher education for British South Asian Muslim women are steadily increasing. The aim of this article, therefore, is to explore motivations and influences for entering higher education and to consider how these may contribute to current discourses surrounding Muslim women in Britain. The possible impact higher education may have on their future relationships and lifestyle choices is also briefly considered. Various notions of 'agency' have been expressed that are characteristic of the ongoing complex assessments made by these women in relation to both perceived familial obligations and their own aspirations. Their articulations suggest that higher education is increasingly viewed as a necessary asset in maintaining and gaining social prestige. This preliminary research indicates that young South Asian Muslim women are continually negotiating and renegotiating their cultural, religious and personal identities and that these processes operate in complex and sometimes contradictory ways.  相似文献   

Learning support and academic achievement among Malaysian adolescents: the mediating role of student engagement     

Zalizan M. Jelas  Norzaini Azman  Hutkemri Zulnaidi  Nor Aniza Ahmad 《Learning Environments Research》2016,19(2):221-240

The aim of this study was to examine the associations between learning support, student engagement and academic achievement among adolescents. We also examined the extent to which affective, behavioural and cognitive engagement play a mediating role in students’ perceived learning support from parents, teachers and peers, and contribute to their academic achievement. Malaysian adolescents (aged 12–17 years, N = 2359) completed a self-administered questionnaire based on an adapted version of the Student Engagement And Learning Support Scale. Item and factor analyses were performed to ensure appropriate psychometric properties of the scales. Pearson correlation analysis identified the relationship between variables and structural equation modelling was conducted to identify the role of student engagement as a mediator between learning support and academic achievement. The study provides empirical support for the hypothesis that perceptions of learning support influence adolescents’ affective, behavioural and cognitive engagement in school in different ways, which in turn influences their academic achievement. Cognitive engagement seemed to be the best predictor of academic achievement and the strongest mediator for all three types of learning support. Behavioural engagement was negatively associated with academic achievement, and affective engagement did not have a direct relationship with academic achievement, although it contributed indirectly through cognitive and behavioural engagement. The results of this study provide a basis for policy makers to initiate prevention and intervention programs for increasing the quality of parent–child, teacher–student and peer–peer relationships which ultimately could lead to improved academic competence and outcomes.  相似文献   

Heterogeneity in Perceptions of Parenting Among Arab Refugee Adolescents in Jordan          下载免费PDF全文

Judith G. Smetana  Ikhlas Ahmad 《Child development》2018,89(5):1786-1802

Heterogeneity in parenting was examined in 883 Arab refugee adolescents in Jordan (M_age = 15.01 years, SD = 1.60). Latent profile analyses of five parenting dimensions rated separately for mothers and fathers yielded authoritative, authoritarian, indifferent, punitive, and for mothers, permissive profiles, with most mothers (60%) and fathers (66%) classified as authoritative. Parenting was more often authoritative for women than men and punitive (for fathers) or permissive (for mothers) of boys than girls. Authoritative fathers and authoritarian mothers were better educated than punitive parents, whose offspring reported more norm breaking and internalizing symptoms and lower academic achievement than other youth. Adjustment was better when adolescents had at least one authoritative parent than when parents were either consistent or discrepant but nonauthoritative.  相似文献   

Beyond Community College Accountability: Using Data to Investigate Best Practices for Institutional Improvement     

Omar S. López 《Community College Journal of Research & Practice》2013,37(1):86-90

The Voluntary Framework of Accountability (VFA) launched in 2011 is the first national system of community college accountability. Sponsored by the American Association of Community Colleges (AACC) in collaboration with the Association of Community College Trustees and the College Board, the VFA will shortly report to the public on measures of student progress and learning outcomes and on measures of workforce, economic, and community development. The author of this paper proposes that AACC move beyond community college accountability toward creating and sustaining, among college administrators, a common culture of VFA data use to investigate best practices for institutional improvement. To advance this proposition, the discourse presented centers on a proof-of-concept model. The study uses longitudinal data to illustrate its potential for community college administrators to identify best practices for improving institutional performance in first-year college retention.  相似文献   

Physiological characteristics of elite and sub-elite badminton players     

Cheong Hwa Ooi  Albert Tan  Azwari Ahmad  Kien Weng Kwong  Ruji Sompong  Khairul Aswadi Mohd Ghazali 《Journal of sports sciences》2013,31(14):1591-1599

Abstract

The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO_2max 56.9 ml · kg^?1 · min^?1 (s = 3.7) and 59.5 ml · kg^?1 · min^?1 (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance.  相似文献   

Influence of expectation and campus racial climate on undergraduates' interracial interaction     

Ezhar Tamam  Fazilah Idris  Wendy Yee Mei Tien  Mona Alkauthar Ahmad 《Asia Pacific Journal of Education》2013,33(3):295-309

In this study, the authors examine the influence of interracial interaction expectation and campus racial climate perception on attitudes toward interracial interaction which, in turn, influences the levels of interracial interaction among students at a multicultural university in Malaysia. Interaction across race is fundamental to students' growth and development. Responses from 193 Malay and 165 Chinese students were analysed by means of hierarchical regression. Results support the hypothesized influence of interracial interaction expectation and campus racial climate perception on attitudes toward interracial interaction for the Chinese students. For the Malay students, however, only interracial interaction expectation is significant. Attitudes toward interracial interaction, in turn, significantly predict levels of interracial interaction for both groups. The results support the hypothesized differential strength of relationships among the variables for the two racial groups. Implications for higher education are discussed.  相似文献