《结构化学》课程教学改革新探

结构化学是化学专业的一门专业基础课程。由于课程比较难,学生不太重视等原因,本门课程的教学效果不是很理想。本文从教学模式、教学方法和手段以及考核方式多方面进行探讨,旨在进一步提高本门课程的教学质量。     

“原子结构”入门知识的教学设计

无机化学中原子结构作为物质结构的入门知识抽象、公式复杂,学生很难适应,难以转变思维模式,严重影响整个物质结构知识、元素化学和后续课程的学习,若从预备知识结合化学史、三种描述方式、多媒体演示几方面进行教学设计,不仅激发学生学习兴趣和自信心,且能事半功倍。     

Augmented reality in informal learning environments: A field experiment in a mathematics exhibition

Recent advances in mobile technologies (esp., smartphones and tablets with built-in cameras, GPS and Internet access) made augmented reality (AR) applications available for the broad public. While many researchers have examined the affordances and constraints of AR for teaching and learning, quantitative evidence for its effectiveness is still scarce. To contribute to filling this research gap, we designed and conducted a pretest–posttest crossover field experiment with 101 participants at a mathematics exhibition to measure the effect of AR on acquiring and retaining mathematical knowledge in an informal learning environment. We hypothesized that visitors acquire more knowledge from augmented exhibits than from exhibits without AR. The theoretical rationale for our hypothesis is that AR allows for the efficient and effective implementation of a subset of the design principles defined in the cognitive theory of multimedia learning. The empirical results we obtained show that museum visitors performed significantly better on knowledge acquisition and retention tests related to augmented exhibits than to non-augmented exhibits and that they perceived AR as a valuable and desirable add-on for museum exhibitions.     

Anthropomorphisms in multimedia learning: Attract attention but do not enhance learning?

Anthropomorphizing graphical elements in multimedia learning materials improves learning outcomes. The reasons for enhanced learning are unclear. We extended a seminal anthropomorphism study in order to examine whether the effect of anthropomorphisms on learning outcomes, both immediate and delayed, is caused by the anthropomorphized elements' effects on attention distribution or by elevated positive affective–motivational states. The study had a partial 3 × 2 design (the materials' graphics: schematic vs. black‐and‐white anthropomorphisms vs. colourful anthropomorphisms × eye tracker: present vs. absent). The participants were university students (N = 181). Unexpectedly, we found no significant effect of anthropomorphisms on learning outcomes. Anthropomorphisms significantly affected attention distribution during initial fixations but not overall. Modest effect on enjoyment was found, but no such effect was detected as concerns flow and generalized positive affect. We also found that the eye tracker's mere presence had slight adverse effects on learners, but these effects did not compromise learning.     

Cluster-Based Saliency-Guided Content-Aware Image Retargeting

Straightforward image resizing operators without considering image contents (e.g., uniform scaling) cannot usually produce satisfactory results, while content-aware image retargeting aims to arbitrarily change image size while preserving visually prominent features. In this paper, a cluster-based saliency-guided seam carving algorithm for content-aware image retargeting is proposed. To cope with the main drawback of the original seam carving algorithm relying on only gradient-based image importance map, we integrate a gradient-based map and a cluster-based saliency map to generate a more reliable importance map, resulting in better single image retargeting results. Experimental results have demonstrated the efficacy of the proposed algorithm.     

Use of instructional technology to improve teacher candidate knowledge of vocabulary instruction

Teacher educators play an influential role in the chain of improvement needed to address gaps in vocabulary knowledge and performance for some children. If created in careful accordance to design principles, multimedia can serve as a tool to improve preservice teacher knowledge in this domain. The present experimental study investigated a multimedia-based intervention, which pairs a modeling video with a Content Acquisition Podcast (i.e., video plus CAP), to teach preservice teachers (n = 101) about an effective vocabulary intervention for students at risk for or with learning disabilities. Preservice teachers were randomly assigned to either watch a video plus CAP or read a practitioner-friendly reading on vocabulary instruction. Those who watched the video plus CAP significantly outperformed the comparison group on a posttest and maintenance test of knowledge.     

DAB电子节目指南结构优化及应用

电子节目指南(EPG)作为数字多媒体广播的一种数据业务,在DAB中被广泛使用。而随着DAB节目的丰富,EPG内容增加。受传输速率的限制,传统EPG结构使其内容的解码显示影响到了用户的体验。针对DAB电子节目指南的内容、结构及其作用,提出一种可以快速获取EPG必要内容的业务说明信息(PI)结构方案,并论证了方案的可行性。     

一种多媒体传感器网络低能耗分簇协议

多媒体传感器网络面临的主要挑战是在能量受限的情况下传输大量数据。在经典分簇协议LEACH的基础上,提出一种考虑数据量的多媒体传感器网络低能耗分簇协议。在簇头选举阶段,选择剩余能量多和数据量大的节点作为簇头;在成簇阶段,同时考虑节点到簇头的通信距离和节点的数据量让节点加入簇。仿真结果表明,提出的协议能有效提高网络的生命周期。     

多媒体在有机立体化学教学中的优势及注意事项

多媒体技术在立体有机化学教学中能够形象、直观地描述立体化学反应及机理,有效调动学生学习的积极性、激发学生的学习兴趣,有助于提高教学效率。