金属光栅的表面拉曼散射

以纳米量级金履带矩形光栅为模型,研究了表面增强拉曼散射的特性。针对TM和TE模的入射光,采用严格的耦合波原理对金属表面衍射场进行计算。通过计算,具体讨论了光栅周期、占空比、深度以及入射光的波长和入射角对表面增强的影响。     

The ‘Heisenberg’s Microscope’ as an Example of Using Thought Experiments in Teaching Physics Theories to Students of the Upper Secondary School

In this work an attempt is made to explore the possible value of using Thought Experiments (TEs) in teaching physics to upper secondary education students. Specifically, a qualitative research project is designed to investigate the extent to which the Thought Experiment (TE) called ‘Heisenberg’s Microscope’, as it has been transformed by Gamow for the public in his book Mr. Tompkins in Paperback, can function as a tool in the teaching of the ‘uncertainty principle’. The sample in the research consisted of 40 Greek students, in 11 groups of 3–4 students each. The findings of this study reveal that the use of this TE has positive results in teaching the uncertainty principle. Students, based on the TE, were able (i) to derive a formula of the uncertainty principle, (ii) to explain that the uncertainty principle is a general principle in nature and it is not a result of incompleteness of the experimental devices and (iii) to argue that it is impossible to determine the trajectory of a particle as a mathematical line.     

Modelling mathematical argumentation: the importance of qualification

In recent years several mathematics education researchers have attempted to analyse students’ arguments using a restricted form of Toulmin’s [The Uses of Argument, Cambridge University Press, UK, 1958] argumentation scheme. In this paper we report data from task-based interviews conducted with highly talented postgraduate mathematics students, and argue that a superior categorisation of genuine mathematical argumentation is provided by the use of Toulmin’s full scheme. In particular, we suggest that modal qualifiers play an important and previously unrecognised role in mathematical argumentation, and that one of the goals of instruction should be to develop students’ abilities to appropriately match up warrant-types with modal qualifiers.     

Representational Issues in Students Learning About Evaporation

This study draws on recent research on the central role of representation in learning. While there has been considerable research on students’ understanding of evaporation, the representational issues entailed in this understanding have not been investigated in depth. The study explored students’ engagement with evaporation phenomena through various representational modes. The study indicates how a focus on representation can provide fresh insights into the conceptual task involved in learning science through an investigation of students’ responses to a structured classroom sequence and subsequent interviews over a year. A case study of one child’s learning demonstrates the way conceptual advances are integrally connected with the development of representational modes. The findings suggest that teacher-mediated negotiation of representational issues as students construct different modal accounts can support enriched learning by enabling both (a) richer conceptual understanding by students, and (b) enhanced teacher insights into students’ thinking.     

亚波长金属扫描探针的场型结构及其透射特性

利用时谐电磁场理论和时域有限差分数值方法分析了亚波长金属扫描探针电磁场模式的场型结构和空间分布及透射特性等主要的传输性质,导出了亚波长金属探针内球横电模和球横磁模各电磁场分量的解析表达,运用数值求解获得的精确本征值,得到了金属探针内几个低阶模在球横截面内的场型结构．时域有限差分数值模拟研究结果表明,时谐电磁场的空间分布在亚波长金属探针内呈现准周期性振荡变化,并且在传输径向坐标上会出现一个最大值,最大值的位置随光波波长发生改变,研究结果还表明,在亚波长探针内刻蚀可以更好地激发和引导表面等离子体激元波到达出射孔径端口,提高亚波长空心锥的透射率和增强光学仪器的空间分辨率．     

Prospective middle school mathematics teachers’ preconceptions of geometric translations

This article reports an analysis of 44 prospective middle school mathematics teachers’ pre-existing knowledge of rigid geometric transformations, specifically the geometric translations. The main data source for this study was the participants’ responses to the tasks that were presented during semi-structured clinical interviews. The findings of the study revealed that prospective teachers had difficulties recognizing, describing, executing, and representing geometric translations. The results indicated that teacher candidates held various views about the geometric translations: (1) translation as rotational motion, (2) translation as translational motion, and (3) translation as mapping. The results further revealed various interpretations of the vector that defines translations: (1) vector as a force, (2) vector as a line of symmetry, (3) vector as a direction indicator, and (4) vector as a displacement. Although many of the teacher candidates interviewed knew that a vector has a magnitude and a direction, this knowledge did not generally lead them to conclude that vectors define translations.     

Generalized fairing algorithm of parametric cubic splines

INTRODUCTION In Computer Aided Design, fairness is one of the basic requirements for designing curves. If the curves are not fair, the design will be unsatisfactory and the producing process will be discommodious. In practice, there are all kinds of errors such as modelling error and measuring error. It means that the information on the data points may not be accurate. In order to obtain fair curves by interpolating these data points, we should fair the data points first. This is the so…     

Electromagnetic Waves in an Antiferromagnetic Waveguide

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Children talk about learning to draw

This study investigates four- to six-year-old children’s conceptions of learning, by applying the lexicometric method to their oral responses to questions about their learning of drawing, in an individual interview at school. Interviews were videotaped and fully transcribed. Subjects were 26 children from a middle-class background attending public schools in Argentina (in a four-year-old class, a five-year-old class and first grade in elementary school). Differences among groups are described on the basis of correspondence analysis and modal response procedures. Such differences are then systematised into several interrelated dimensions regarding changes in children’s conceptions of learning to draw, namely: learning agency as the internalisation of social mediation, nature of both learner’s and teacher’s actions and mental states, learning goals and temporal frame of reference. Thus, three main conceptions are identified: external agency, external/internal agency and internal agency conceptions, which are associated to the three different school grade groups studied.     

Pupils’ definitions of bullying

Although there has been a growing interest in research on bullying in the last decade the majority of studies have used definitions of bullying and victimisation derived from researchers’ perceptions of the problem. The aim of the present study was to examine pupils’ definitions of bullying in school. The participants were 166 pupils in the top two years in five primary schools in Ireland (two in urban areas and three in rural areas). There were 89 male and 77 female participants, with a modal age of 12 years. An interview was designed to elicit pupils’ perceptions of the defining characteristics of bullying behaviour including (I) the behaviours described as bullying, (II) the importance of repetition, (III) the importance of intention, (IV) the effect on the victim, (V) the role of provocation and (VI) imbalance of power. The results suggest that repetition, intention, and a lack of provocation may not be central to pupils’ definitions of bullying. These results indicate some differences between pupils and researchers on what constitutes the most important defining characteristics of bullying. This suggests that approaches to bullying intervention programmes may need to be reconsidered in light of these findings.     

Studies of surface plasmon resonance sensor using bi-beam differential measurement approach

In this paper, a low-cost measurement approach with bi-beam was presented, which can be used for real-time detection and online analysis of solution refractive index, based on systematical analysis and experiments of conventional detection methods on surface plasmon resonance sensor. This novel method was analyzed theoretically and based on it a sensor system set was established. The factors that affect the sensor's sensitivity and working range were discussed. The angular adjustment setup was simplified, errors produced by movable components were avoided and the maneuverability was enhanced with this new method. The noiseproof feature and stability of the sensor system were greatly improved as well.     

Teacher interpersonal behaviour and student achievement in English as a Foreign Language classrooms in China

We examined the relationship between English as a Foreign Language (EFL) teachers’ interpersonal behaviour and students’ fluency in English in secondary education in China. A total of 160 students from four classes in the southwest part of China were asked to assess their teachers’ interpersonal behaviour using the Questionnaire on Teacher Interaction (QTI). This was the first time that the QTI was successfully translated and used (in EFL classrooms) in China. Cronbach’s α reliability coefficients for the scales were adequate, while confirmatory factor analyses provided support for the theoretical framework behind the questionnaire. Results showed that teacher uncertainty was negatively correlated with student achievement. Furthermore, the degree of teacher cooperation with students was the only significant predictor for student achievement, but its effect disappeared when student background variables were taken into account. Results also indicated a discrepancy between students’ perceptions of preferred and actual teacher interpersonal behaviour. The tolerant-authoritative profile was the most common interpersonal style based on Chinese students’ perceptions.     

Learning environment profiles of Turkish secondary biology classrooms

The purposes of this study were to examine how Turkish students perceived their biology classroom environment, how their perceptions compared to those of students in other countries, and what classroom learning environment profiles could be discerned in Turkish high school biology classrooms. Data were gathered from 1,474 high school students in four inner city schools, in Bursa, Turkey. A total of 11 biology teachers participated in the study with 52 of their classes. Data on students’ perceptions of their learning environment were collected with the What Is Happening In this Class? (WIHIC) questionnaire. Results indicated that Turkish classrooms were perceived as being low in terms of Teacher Support and high in terms of Task Orientation. Six distinct classroom learning environment profiles were found: the ‘self-directed learning classroom’, ‘task-oriented cooperative learning classroom’, ‘mainstream classroom’, ‘task-oriented individualised classroom’, ‘low-effective learning classroom’ and ‘high-effective learning classroom’. The most common profile was the ‘mainstream classroom’ for which all WIHIC scales had medium–high scores.     

The Project in Intergroup Education and Sarason’s Modal Process of Change: A Historical Exemplar of Educational Reform

In 1971, Seymour Sarason published his now classic book on educational reform entitled, The Culture of the School and the Problem of Change. In the text, Sarason devotes an entire chapter to what he terms the modal process of change. The characteristics of this process, unfortunately, remain salient in today’s educational climate. The Project in Intergroup Education was an educational reform that attempted to bring issues of intolerance and discrimination into K-12 classrooms during the post WWII era. In this article, I contend that using the conceptual lens suggested by Sarason’s modal process, the examination of the Project offers a historical exemplar of an educational change and illuminates ways in which we might seek to challenge the typical implementation of change. Specifically we can see counterevidence to the modal process in the Project’s emphasis on the significance and inclusion of the classroom teacher, the importance of school contexts and particular needs of students, and in the ways in which the curricular work of participating teachers evinced the changes sought by Project leaders.

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Three dimensions of reflective thinking in solving design problems: a conceptual model

Design tasks are omnipresent in our everyday lives. Previous research shows that reflective thinking is one of the critical factors in solving design problems. Related research has attempted to capture designers’ reflective thinking process. Yet a close inspection of designers’ reflective thinking taking place during their design process demands further effort. To understand designer’s reflective practice and to find better ways to promote novices’ reflective thinking in solving real-world design problems, a comprehensive model was developed. This model identified three dimensions to guide the understanding of designers’ reflective thinking during a design process: (1) the timing of reflection, indicating the points in the process where reflective thinking occurs, (2) the objects of reflection, showing the different types of objects that designers may reflect upon, and (3) the levels of reflection, referring to the different levels of designers’ reflection. This model provides for meaningful aspects of reflective thinking to be situated in a design process, which can guide educators and instructional designers in developing appropriate learning environments for facilitating novice and practicing designers’ reflective thinking. Moreover, the model can serve as a stepping stone for further research.     

A fusion of horizons: students’ encounters withWill and Wave

In a case study, I applied philosophical hermeneutic principles in an advanced level EFL writing class in Taiwan. A “fusion of horizons” occurs at the junction of two intertwined interpretations: one from our socio-historical tradition and the other from our experience of novel phenomena. I explored students’ hermeneutic horizons in relation to Nietzsche’s textWill and Wave. Data collection was through classroom observations, informant interviews, and an analysis of three students’ interpretive essays. The results indicated that students experienced particular difficulties comprehending metaphors and the author’s purpose. Comprehension was a painstaking effort for most students because of their perceived ambiguity of Nietzsche’s message. Nevertheless, the text evoked personal stories and new perspectives for some students     

Nanophotonics and negative ε materials

INTRODUCTION Photonics circuits or integrated optics circuits are currently orders of magnitude larger in physical dimensions than their electronic counterparts. Whereas FET type transistors have lengths on the order of 50 nm passive optical devices, even those based on photonics crystals have sizes on the order of wavelength of 1 μm. For active devices the sizes are even larger, essentially depending on the matrix element of the interaction of interest. Regarding the packing density de…     

Learning within the worlds of reifications, selves, and phenomena: expanding on the thinking of Vygotsky and Popper

A framework, termed the RSP, is proposed. It is mainly for analyzing and explaining how learning occurs. This framework is grounded in the social-cultural perspective, in particular, in the thinking of both Vygotsky and Popper. Although the thinking of Popper is generally not referred to as having a social-cultural orientation, mostly due to misunderstanding, he and Vygotsky are defensibly complementary. In a nutshell, Vygotsky’s social-cultural (inter-psychological) plane is enriched by Popper’s distinction between physical and conceptual-abstract worlds, while Popper’s mental world is enhanced by Vygotskian and post-Vygotskian work emphasizing personality, that is, the whole self. Integrating and expanding on both Vygotsky and Popper, the RSP framework further unpacks how learning occurs as dialectical interactions between the Worlds of reifications (R), selves (S), and phenomena (P). The World of Reifications (R) extends Popper’s World 3 by emphasizing the developmental nature of conjectures to theories. The World of Selves (S) now extends Popper’s World 2 from cognitive dimensions to the whole individual. And the World of Phenomena (P) extends Popper’s World 1 to include the relationships between objects forming phenomena, including the physical, social, and spiritual dimensions. The interactions among the three Worlds result in five learning outcomes: cognition, metacognition, action, reflective action, and epistemic cognition. It is contended that these five outcomes are necessary criteria for holistic learning. The framework is then applied to analyzing various issues such as resolving lethal mutations, identity, and learning as becoming.     

Examining the Impact of Student Use of Multiple Modal Representations in Constructing Arguments in Organic Chemistry Laboratory Classes

This study was designed to examine students’ use of multiple modal representations within their written arguments as a consequence of completing a series of investigations of an organic chemistry laboratory course. One hundred and eleven students from a major Midwestern university were involved in using the Science Writing Heuristic (SWH) approach where they are required to use the argument structure of question, claim, evidence and reflection in completing the written report for their instructor on their laboratory investigations. Results indicate that students who achieved a high score for embedded multiple modal representations in the evidence section also constructed high quality arguments. That is, students who were able to embed multiple modal representations in evidence made strong reasoned connections to support their claim(s) and construct a cohesive argument. Further, there were strong correlations between the laboratory examination score and holistic quality of argument. This study suggests there is a need to build support structures pedagogically for the individual in order to help students understanding the role and function of multiple modal representations in science.     

不同介质形态对石墨结构光子晶体带隙的影响

利用平面波法研究了不同介质形态对二维石墨结构光子晶体的TE偏振模式带隙和TM偏振模式带隙的影响。研究发现,改变构成二维石墨结构光子晶体的介质柱的形态,分别选用圆柱、三角柱、矩柱、五角柱、六角柱等形态,在填充面积比相等时,石墨结构光子晶体的TE和TM两种偏振模式光子带隙都保持不变。