一种新型磨矿介质设计与磨矿试验研究

为了缓解硫化矿选厂粗粒欠磨与细粒过磨等问题,设计了一种新型磨矿介质-黄金分割锻球.通过2种介质磨矿试验对比,表明锻球磨矿具有针对性强,磨矿效果好,试验指标显示：锻球磨矿的产品粗粒会减少0.80%,中等粒级增加3.26%,细粒减少2.46%.分析发现锻磨在磨矿中与物料接触有相当一部分为线接触,细粒因粗粒的“架桥”作用而减少了过粉碎,钢球介质与矿物接触为点接触,粗粒的架桥作用不明显,对粗粒与细粒的粉碎作用具有一致的概率,故选择性差,过粉碎现象严重.设计的锻球介质能明显的缓解粗粒欠磨与细粒过粉碎等问题.     

Video as a medium of oral health education for children with mental handicaps

This study assessed the usefulness, appropriateness, and relevance of a video as an oral health education medium for children with mental handicaps and for preschool groups where children with mental handicaps and healthy children are taught together. The evaluated video was designed for children with mental handicaps but was also recommended for integrated groups. Forty children with mental handicaps from four special education classes and two nursery school groups, 151 normal children from 11 nursery school groups, and the teachers of these classes and groups evaluated the material. The assessment of the material's value was based on the teachers' records of their experiences with the material, their records of the children's opinions and discussions about the material, and their records of drawing interviews with the children. Based on the evaluation, it is apparent that, when used by trained teachers, professionally made videos designed for children with mental handicaps can be useful and valuable aids in educating children of different levels of mental and social development about oral health. Integrated groups need videos featuring both children with mental handicaps and normal role models and with a diversity of contents that will interest and challenge both types of audiences.E.