太阳能二次聚集器聚光性能研究

采用蒙特卡洛射线踪迹法,ProE和TracePro软件技术,模拟分析了多棱台与一次抛物面、复合抛物面二次聚集器与一次抛物面两级聚集器的太阳光聚集传输特性。通过对比,发现多棱台二次聚集器的几何聚光比为1.4左右(约为复合抛物面聚集器的70%)。多棱台与一次抛物面、复合抛物面二次聚集器与一次抛物面两级聚集器圆筒侧壁和底面的太阳能流密度分布图像相当(沿圆周方向,复合抛物面两级聚集器相对比较平滑)。结论为反射二次聚集器技术发展提供理论依据。     

钢梁与钢筋混凝土桥墩的新型刚节点联结形式及其静载反复试验

提出了一种新型的桥梁钢梁与钢筋混凝土桥墩的刚节点联结形式．刚节点内部构件间的连接全部采用高强度螺栓连接方式且施工方便，能够较理想地将上部结构弯矩传递到下部结构，剪力传递钢板承受了大部分的水平剪力．通过静荷载反复试验获得了有关这种新型结构性能方面的有效数据，试验结果表明该结构内部应力传递路径明确，并具有良好的抗震性能．有关结构的强度和塑性变形的计算及试验结果均表明，这种结构即使在发生很大变形的情况下，也能保持良好的能量吸收功能且没有出现因应力集中而发生的局部曲屈现象．由于避免使用了价格昂贵的支座，采用这种新型组合结构形式不但具有良好的抗震性能，同时可以降低桥梁的建设成本．     

试论社会转型期我国政府绩效评估的路径选择

政府绩效的核心问题是公共责任的实现程度与效果,表现为一系列量化与非量化指标,绩效评估是对这些指标的综合反映。在传统和现代的挤压下,我国政府绩效评估的基础呈现鲜明特色。在社会转型期,着眼于实践"科学发展观"的要求,绩效评估要求准确界定政府职能,科学设立评估指标,追求以低成本、高效能的方式为社会提供公共产品和服务,并以公共责任为本打造"绩效政府"。     

谈钢琴演奏技巧与音乐表现的关系

演奏技巧与音乐表现是相辅相成的,演奏者只有华丽的技巧是不够的,只有用心去领会作品的内涵才能理解作曲家的思想.     

PowerPoint slide provision and student performance: the moderating roles of self-efficacy and gender

Research on the pedagogical value of providing students with PowerPoint (PPT) slide handouts has produced mixed results. One reason for the inconsistent findings may be that most studies in this stream of research have neglected to examine individual differences. In the current study, we aimed to advance research on the pedagogical value of providing students with access to PPT slide handouts by examining whether self-efficacy and gender influence the effect of PPT slide provision on academic performance. We found no evidence to suggest that the provision of slide handouts has broad, unconditional pedagogical value. Instead, we found that both self-efficacy and gender moderated the extent to which the availability of the handouts enhanced or hindered students’ performance. As predicted, both students high on self-efficacy and males performed significantly better when they were provided with handouts. Conversely, students low on self-efficacy performed significantly worse when the handouts were provided. Female students also trended toward lower performance when the handouts were provided. Additionally, we found that students who were provided with PPT handouts perceived their instructor as more effective, and that this relation was mediated by students’ feeling of preparation. Finally, students also considered the provision of PPT handouts more valuable to their learning and course performance than one-to-one interactions with the professor. Implications for research and practice are discussed.     

钢琴曲《喷泉》的音乐特征与演奏分析

钢琴曲《喷泉》的音乐本体;浪漫主义音乐特征和丰富的演奏技巧;为演奏者和欣赏者提供参考。     

Perceptions of the school self-evaluation process: the case of Abu Dhabi

The Abu Dhabi Education Council (ADEC) has initiated educational change and school improvements. As part of the school reform agenda, ADEC has introduced school self-evaluation-Irtiqaa (SSE-Irtiqaa). This research probes the effectiveness of school administrators (SAs), including principals, vice principals, academic principals, and heads of faculty, and their perceptions of the implications and implementation of SSE-Irtiqaa. The study also intends to improve school quality and help benchmark Abu Dhabi public schools with international academic standards, by tracing challenges faced during the SSE-Irtiqaa process. Public SAs are the participants of this study. This research is an exploratory case study that employed a qualitative research tool. Semi-structured individual interviews were conducted with 14 administrators representing 6 public schools in Abu Dhabi. Findings and recommendations shed light on the areas and paths of development required to facilitate and improve the SSE-Irtiqaa process.     

Li1xNaxV3O8电极在硫酸锂-水-乙醇体系中的电化学性能

A series of Lil-xNaxV3O8 materials was prepared by solution reaction followed by calcination method and their electrochemical performances in 2 M LieSOa-water-ethanol solution as negative electrodes for aqueous electrolyte lithium ion battery were studied and compared each other. X-ray diffraction analysis revealed that partially substituting sodium for lithium in LiV3Os could increase the interlayer distances of （100） plane. Cyclic voltammetric experiments have demonstrated that the Li^＋ insertion and extraction kinetics of Li0.7Na0.3V3O8 is superior to that of LiV3O8. Charge/discharge results showed that the discharge specific capacity of Li0.7Na0.3V3O8 electrode is higher than that of LiV3O8 electrode.     

双金属微悬臂梁的选材及热机械性能分析

由微悬臂梁结构组成的红外焦平面阵列(FPA)是基于微机电系统结构的非制冷型红外成像系统的核心技术。通过对Al/SiNx双材料体系的理论分析,得出了微悬臂梁的热机械性能与双层梁的厚度比之间的关系。     

美国全纳教育对学习障碍学生的教育影响

全纳教育通过为有障碍和无障碍学生建立学习型社区,使所有学生在适龄的普通教育场景接受相同的教育。全纳教育代表所有学生的利益,提倡教师要为差异而教。学习障碍学生是美国中小学接受特殊教育的最大群体。全纳教育对美国学习障碍学生的教育安置、学业进步和社会性发展均产生一定影响。研究全纳教育对学习障碍学生的教育影响有助于提高全纳教育的效能并对评估和推进全纳教育起到指导作用。