Scaffolding Students’ Online Critiquing of Expert- and Peer-generated Molecular Models of Chemical Reactions

In this study, we developed online critiquing activities using an open-source computer learning environment. We investigated how well the activities scaffolded students to critique molecular models of chemical reactions made by scientists, peers, and a fictitious peer, and whether the activities enhanced the students' understanding of science models and chemical reactions. The activities were implemented in an eighth-grade class with 28 students in a public junior high school in southern Taiwan. The study employed mixed research methods. Data collected included pre- and post-instructional assessments, post-instructional interviews, and students' electronic written responses and oral discussions during the critiquing activities. The results indicated that these activities guided the students to produce overall quality critiques. Also, the students developed a more sophisticated understanding of chemical reactions and scientific models as a result of the intervention. Design considerations for effective model critiquing activities are discussed based on observational results, including the use of peer-generated artefacts for critiquing to promote motivation and collaboration, coupled with critiques of scientific models to enhance students' epistemological understanding of model purpose and communication.     

谈明清家具造型及纹饰特征

明清家具在我国家具制作史上占有极其重要的地位.明清家具从制作风格、造型结构、选用材质、装饰手法、造型艺术等方面典型地体现了中国家具所具有的极其精湛的工艺价值、极高的艺术欣赏价值、丰富的历史文化价值和收藏价值.     

UML包与B结合的形式化建模研究

分析UML和B相互转化的难点后,提出一种既克服转化难点又能得到简单证明义务的建模机制:选择包作为交互替换的UML实体去说明一个B组件和包的完整类图到一个单独B组件的转化映射,同时结合实例加以说明该机制的可行性.