“脚手架”如何变成了“绊脚石”——小学数学中的图示障碍研究

小学数学教材和教师的教学过程中提供了大量图文与习题结合的图示,其中大部分本身是作为学生情境支架而设计的,以支撑学生跨越从生活数学到抽象符号数学之间的发展鸿沟。然而,实证调查测试表明,一些数学图示不仅没有起到“脚手架”作用,反而成了干扰学生正确理解题意的障碍。进一步分析发现,这些图示障碍内在的图文匹配度、契合学生的理解度和对学生学习的支持度之间存在正向影响关系;图示内部缺乏一致性、图像内容编排不合理以及图示信息呈现不恰当是形成6种典型图示障碍的三大主因,且通常发生在多媒体学习“选择—组织—整合”词语和画面的不同认知阶段。研究结果为设计和使用数学图示提供了有益启示:遵从多媒体学习的匹配设计、学习者中心的设计和深度学习的情境支架设计三大学习设计原则,不仅可以使图示障碍得到有效控制与消除,也是回归图示本身所赋有的“脚手架”功能的有效途径。

抛锚式教学法在程序设计教学中的实践

基于非计算机专业人员自己编写程序的需求日益增长,分析建构主义学习理论的思想内核和外延,提出将抛锚式教学法用于非计算机专业C语言程序设计教学,从早期熟悉阶段、中期学习阶段和后期应用阶段介绍具体教学应用实践,最后通过教学效果评价说明该教学法的有效性。

Immobilization of heparin on decellularized kidney scaffold to construct microenvironment for antithrombosis and inducing reendothelialization

In recent years, rapid development of tissue engineering technology provides possibilities for the construction of artificial tissues or organs. In construction of engineered kidneys, researchers used native decellularized extracellular matrix(ECM) as the scaffolds to recellularization. However, thrombosis has been a great issue that hinders the progress of transplantation in vivo. In this study, heparin was immobilized to the collagen part of decellularized scaffold with collagen-binding peptide(CBP). Through the anticoagulant and endothelial cell reperfusion experiments, it can be demonstrated that the heparinized scaffolds absorbed less platelets and red blood cells which can effectively reduce the formation of thrombosis. Moreover, it is conducive to longterm adhesion of endothelial cells which is important for the formation of subsequent vascularization. Taken together, our results reveal that the whole kidney can be modified by CBP-heparin composite to reduce the thrombosis and provide the better conditions for neovascularization.