Social preference choices in late elementary school: Within and across group nominations

This study examined the social preference nominations (i.e., “liked most” and “liked least”) in relation to peer group and classroom social dynamics in a sample of 622 fifth graders from 11 schools in a southeastern state. Liked most and liked least nominations were given to a small concentration of students within classrooms. The top five nominees for liked most and liked least tended to be in peer groups and associated with at least one classmate who shared their position as a top nominee. The majority of liked most nominations in a classroom were made toward members inside the nominator's group, whereas the majority of liked least nominations were made toward peers outside one's group. Students in the same peer group were more likely to nominate the same peers as liked most than were students who did not affiliate together. In contrast, the concordance for liked least nominations was moderate at both the peer‐group and classroom level. Implications for school‐based social interventions are discussed. © 2009 Wiley Periodicals, Inc.     

SLIPS-TENG: robust triboelectric nanogenerator with optical and charge transparency using a slippery interface

Energy harvesting devices that prosper in harsh environments are highly demanded in a wide range of applications ranging from wearable and biomedical devices to self-powered and intelligent systems. Particularly, over the past several years, the innovation of triboelectric nanogenerators (TENGs) that efficiently convert ambient kinetic energy of water droplets or wave power to electricity has received growing attention. One of the main bottlenecks for the practical implications of such devices originates from the fast degradation of the physiochemical properties of interfacial materials under harsh environments. To overcome these challenges, here we report the design of a novel slippery lubricant-impregnated porous surface (SLIPS) based TENG, referred to as SLIPS-TENG, which exhibits many distinctive advantages over conventional design including optical transparency, configurability, self-cleaning, flexibility, and power generation stability, in a wide range of working environments. Unexpectedly, the slippery and configurable lubricant layer not only serves as a unique substrate for liquid/droplet transport and optical transmission, but also for efficient charge transfer. Moreover, we show that there exists a critical thickness in the liquid layer, below which the triboelectric effect is almost identical to that without the presence of such a liquid film. Such an intriguing charge transparency behavior is reminiscent of the wetting transparency and van der Waals potential transparency of graphene previously reported, though the fundamental mechanism remains to be elucidated. We envision that the marriage of these two seemingly totally different arenas (SLIPS and TENG) provides a paradigm shift in the design of robust and versatile energy devices that can be used as a clean and longer-lifetime alternative in various working environments.     

Teacher Evaluation and Effectiveness in Hong Kong: Issues and Challenges

This article first provides an overview of teacher effectiveness and evaluation in Hong Kong. Several studies related to classroom environment and teacher behavior in selected subjects are referenced, as are recent studies of teachers instructional leadership. Finally, the preliminary use of the Revised Classroom Observation Instrument (RCOI) from the Louisiana School Effectiveness Study in three secondary schools is reported. The results from using the RCOI in Hong Kong indicate that some items may be irrelevant in the Hong Kong context (e.g., physical characteristics), while more items may be needed to reflect good teaching in Hong Kong (e.g., questioning skills). In addition, the potential use of teacher profiles to drive staff development and school improvement is explored.     

年底DV大看点——索尼意外急降 佳能高调上市

每年岁尾，都是本年度最后一批新机上市的时节．这批新上市的机器一般都是在9月-10才发布的．而且基本上都是面向高端市场．今年也不例外。新机上市是市场的规律所在，而因此造成某些机型降价也是正常的．不过近期有点意外的是在松下、佳能、JVC都推出05年最高端机型的时候．     

Examining students’ affective commitment toward country: a case study of a Singapore primary school

The purpose of this study was to examine students’ affective commitment toward Singapore. Affective commitment refers to the sense of attachment to the nation state. The sample was taken from 286 students in a primary school. In the first section of the paper, we described the design of a Likert-type Affective Commitment to Country questionnaire. Factor analyses (principal component analysis and confirmatory factor analysis) showed evidence of construct validity for the 10-item scale, and an overall Cronbach alpha reliability coefficient of 0.91. In the second section, we reported the statistics related to the students’ affective commitment scores. Overall, a positive affective commitment toward the country was found. Results of our t-test analyses revealed that no statistically significant difference was found between boys and girls for each of the questionnaire items. However, students who had higher academic achievement reported significantly higher scores than their lower ability counterparts with regard to six items of the questionnaire. Suggestions for future research are discussed.     

Enhancing orthographic knowledge helps spelling production in eight-year-old Chinese children at risk for dyslexia

We investigated the effects of enhancing orthographic knowledge on the spelling of Chinese characters and words in 131 eight-year-old Chinese children at risk for dyslexia. The traditional approach (37 children) emphasizing memory and repeated writing was the control condition. The analytic and synthetic approach (ASA, 33 children) stressed insight into character structure. The integrated analytic and synthetic approach added to ASA self-correction and metacognitive activities (INA, 61 children). The children were first asked to write down as many words as possible associated with pictures of home, school, and community; the correctly written words formed the baseline information. The children were then instructed by their classroom teachers in six especially designed short texts and assessed in eight measurable bujian or radical tasks subserving three constructs: morpheme completion, bujian analysis and synthesis and bujian compounding. Multivariate analyses of variance showed that the children in the INA condition outperformed those in the other conditions in three of the measurable bujian tasks. A confirmatory factor analysis verified the stability of the eight tasks and their clustering into three constructs. From these results, we tentatively propose a “bujian sensitivity hypothesis” as a means of helping young Chinese children at risk for spelling disorders.     

Agar-polydimethylsiloxane devices for quantitative investigation of oviposition behaviour of adult Drosophila melanogaster

Drosophila melanogaster (fruit fly) is a model organism and its behaviours including oviposition (egg-laying) on agar substrates have been widely used for assessment of a variety of biological processes in flies. Physical and chemical properties of the substrate are the dominant factors affecting Drosophila''s oviposition, but they have not been investigated precisely and parametrically with the existing manual approaches. As a result, many behavioral questions about Drosophila oviposition, such as the combined effects of the aforementioned substrate properties (e.g., exposure area, sugar content, and stiffness) on oviposition and viability, and their threshold values, are yet to be answered. In this paper, we have devised a simple, easily implementable, and novel methodology that allows for modification of physical and chemical composition of agar substrates in order to quantitatively study survival and oviposition of adult fruit flies in an accurate and repeatable manner. Agar substrates have been modified by surface patterning using single and hexagonally arrayed through-hole polydimethylsiloxane (PDMS) membranes with various diameters and interspacing, as well as by substrate stiffness and sugar content modification via alteration of chemical components. While pure PDMS substrates showed a significant lethal effect on flies, a 0.5 mm diameter through-hole access to agar was found to abruptly increase the survival of adult flies to more than 93%. Flies avoided ovipositing on pure PDMS and on top of substrates with 0.5 mm diameter agar exposure areas. At a hole diameter of 2 mm (i.e., 0.25% exposure area) or larger, eggs were observed to be laid predominately inside the through-holes and along the edges of the PDMS-agar interface, showing a trending increase in site selection with 4 mm (i.e., 1% exposure area threshold) demonstrating natural oviposition rates similar to pure agar. The surface-modified agar-PDMS hybrid devices and the threshold values reported for the substrate physical and chemical conditions affecting oviposition are novel; therefore, we advocate their use for future in-depth studies of oviposition behaviour in Drosophila melanogaster with accuracy and repeatability. The technique is also useful for development of novel assays for learning and decision-making studies as well as miniaturized devices for self-assembly of eggs and embryonic developmental investigations.     

圆翼管换热器传热分析

圆翼管换热气是采暖通风工程中常用的换热设备。本文通过对圆翼管传热性能进行分析，提出在暖通工程中合理采用圆翼管换热气器的设想。