Understanding the integral: Students’ symbolic forms

Researchers are currently investigating how calculus students understand the basic concepts of first-year calculus, including the integral. However, much is still unknown regarding the cognitive resources (i.e., stable cognitive units that can be accessed by an individual) that students hold and draw on when thinking about the integral. This paper presents cognitive resources of the integral that a sample of experienced calculus students drew on while working on pure mathematics and applied physics problems. This research provides evidence that students hold a variety of productive cognitive resources that can be employed in problem solving, though some of the resources prove more productive than others, depending on the context. In particular, conceptualizations of the integral as an addition over many pieces seem especially useful in multivariate and physics contexts.     

Crystallographic Understanding of Photoelectric Properties for C60 Derivatives Applicable as Electron Transporting Materials in Perovskite Solar Cells

Hundreds of C₆₀ derivatives stand out as electrontransporting materials(ETMs), for example, in perovskite solar cells(PSCs), due to their properties on electron extraction or defect passivation. However, it still lacks of guidelines to update C₆₀-based ETMs with excellent photoelectric properties. In this work, crystallographic data of eight C₆₀-based ETMs, including pristine C₆₀ and the well-known PCBM as well as six newly synthesized fullerenes, are analyzed to establish the connections between derivatized structures and photoelectric properties for the typical carbon cluster of C₆₀. In terms of packing centroid-centroid distance between neighboring carbon cages, the crystallographic data are useful for probing photoelectric properties, such as electrochemical properties, electron mobility and photovoltaic performances, and therefore facilitate to design novel C₆₀-based ETMs for PSCs with high performances.     

对工科高等数学的研究性教学的一些认识

当前"研究性教学"是比较提倡的教学方式,它有利于培养学生的数学思想和数学素养.为了更好地进行"研究性教学",教师应研究数学史培养学生数学思想,应研究数学教学的认知规律培养学生"研究性学习"习惯,以及进行应用数学知识能力的研究,完美的逻辑体系与学生接受能力的研究,支持这种教学方式的考核方式的研究.     

Nanotechnology and the public: Effectively communicating nanoscale science and engineering concepts

Researchers are faced with challenges when addressing the public on concepts and applications associated with nanotechnology. The goal of our work was to understand the public’s knowledge of nanotechnology in order to identify appropriate starting points for dialog. Survey results showed that people lack true understanding of concepts associated with atoms and the size of the nanoscale regime. Such gaps in understanding lead to a disappointing lack of communication between researchers and the public concerning fundamental concepts in nanoscale science and engineering. Strategies are offered on how scientists should present their research when engaging the public on nanotechnology topics. Since the time of writing, O.M. Castellini has relocated to the Department of Science and Technology, Museum of Science and Industry, 57th Street and Lake Shore Drive, Chicago, IL 60637, USA.     

Multi-pulse operation of a Kerr-lens mode-locked femtosecond laser

Our experimental results show that the presence of a proper amount of negative group velocity dispersion is essential to multi-pulse operation of a Kerr-lens mode-locked femtosecond laser. We demonstrate that the pulse separations and the number of pulses contained within a cavity round trip are strongly dependent on the initial perturbations. The results allow us to get a better understanding on the influences of the convoluted self-phase modulation and intra-cavity dispersions on the stable multi-pulse oscillation in a Kerr-lens mode-locked femtosecond laser.     

基于Rasch模型的化学核心概念理解测量研究

学科概念的理解程度直接决定着学习目标的达成与否,国内外科学教育标准均把培养学生科学核心概念理解能力作为提高科学素养宗旨的主要途径。在探查和诊断学生对化学核心概念理解能力上,既需要考虑具体的学科概念,也需要考虑到学生当前的认知阶段。尽管有很多工具可用来诊断学生的概念理解能力,与其他诊断工具相比,二段式诊断工具具有精确性和具体性,且可以大规模地推广和应用。同时,在对诊断方法有效性检验上,Rasch测量模型理论比经典测量理论更具针对性和有效性。以化学学科中"溶液中的离子平衡"概念为例,阐述如何利用二段式诊断方法来设计化学核心概念理解的测量工具,并进一步实证研究如何利用Rasch测量模型理论来对测量工具进行质量检验与修改。     

新时代下化学教学论学科的新使命与新挑战——兼评《化学教学论》教材

在我国科技创新发展需求及新时代基础教育强师计划的背景下,探讨了化学教学论学科面临的新使命:为培养师范生的创新意识和创新能力提供强有力的支撑,为基础化学教育培养学生的创新意识和创新能力提供强有力的引领和指导。分析了达成新使命所面临的新挑战:增进对化学学科内容的理解,提升化学专业对话的能力;融通化学教育、教育心理学、科学哲学等领域,明晰化学教育的理论基础;深度反思与融通国内外化学教育研究成果,明晰化学教学论学科的学术性及独特优势;融通化学教育研究与化学课堂教学实践,弥合二者之间的隔阂;加强化学教育研究成果与化学教师教育课程的整合;进一步提升化学教学论学科的外部认同等。     

基于化学学科理解的电化学主题认识模型研究*

在核心素养导向的化学教学实践新时代背景下,基于化学学科理解构建相应主题的认识模型,提升教师的化学学科理解水平,进而开展素养为本的课堂教学促进教师专业发展,为化学教育理论和实践研究提供了重要的思路和方向。以电化学主题为例,基于化学学科理解构建其认识模型,以期其研究思路和过程对化学学科其他主题的理论和教学研究具有启示作用。