基于儿童认知发展的学龄前儿童APP界面交互设计研究

目的基于3～6岁学龄前儿童认知发展的生理特点与心理特点,探讨学龄前儿童APP的界面交互设计原则,旨在为此类界面交互设计提出方法论指导,从而使学龄前儿童的综合学习能力得到更好的发展。方法通过对国内外学龄前儿童APP界面交互设计理论的归纳整理与优秀APP案例的比较研究,运用学龄前儿童的视觉、听觉、触觉和运动觉的认知发展,结合皮亚杰的认知理论及儿童认知发展心理学的相关理论研究,总结出优秀的学龄前儿童APP设计策略的五个方面,并将其应用于项目实践。结论通过具体案例的设计实践,在APP界面交互设计中初步验证了关于学龄前儿童的认知发展研究的适用性,提出符合儿童认知发展特征的设计策略,满足儿童在线学习的荣誉感和成就感,从而助推学龄前儿童在线学习的积极性和注意力。

High Temperature Friction and Wear Properties of Laser Cladding Ni60 Coating Modified with Rare Earth on 6063 Aluminum Alloy Base

In order to improve the comprehensive performance of aluminum alloy, the surface of 6063 aluminum alloy was modified with Ni60, Ni60+4%CeO2, Ni60+5%Y2O3 and Ni60+5%La2O3 by using laser cladding technology. Hardness experiments, high temperature friction and wear behaviors were carried out. The wear resistance and wear mechanism of each sample and the influence of rare earth on the wear resistance and wear mechanism of the cladding layer by analyzing the friction coefficient, wear tracks, wear amount, phase, composition and micro-morphology after wear of the sample. The hardness of the cladding layer added with rare earth increase significantly and the hardness of the cladding layer presented a gradient distribution. With the increase of load and wear temperature, the wear mechanism of 6063 Al changed from mild to severe wear, the order was two-body abrasive wear to adhesive wear, and then, to severe melting wear and oxidative wear. The wear mechanism of Ni60 cladding layer was mainly peeling wear, oxidation wear and slight ploughing wear. With the increase of load and wear temperature, the degree of peeling wear became more and more serious. With the increase of load and wear temperature of the cladding layer with the optimal rare earth content, the wear mechanism gradually changed from ploughing wear to delamination wear, and contained oxidation wear and plough wear. Compared with the Ni60 cladding layer, the high-temperature friction and wear properties of the cladding layer with the best rare earth content were significantly improved. Compared with the three kinds of rare earth cladding layers, the order of high temperature friction and wear performance from good to poor is Ni60+4%CeO2 cladding layer, Ni60+5%Y2O3 cladding layer, Ni60+5%La2O3 cladding layer.