航空电机轴承参数优化

根据航空电机轴承的工作环境,特别是高速、轻载工况特点,利用动力学仿真分析软件Adore,分析研究了不同组别内、外圈沟曲率半径系数和径向游隙的变化对轴承疲劳寿命、磨损率、兜孔碰撞力、功率损失的影响情况。同时利用正交分析法分析不同组合方案中疲劳寿命、磨损率、兜孔碰撞力及功率损失的变化情况。结果表明:疲劳寿命、磨损率、兜孔碰撞力、功率损失分别随着内圈沟曲率半径系数、外圈沟曲率半径系数增大呈现降低的趋势;疲劳寿命、磨损率、兜孔碰撞力、功率损失随着径向游隙的增大呈现降低的趋势。结合正交分析法和内、外圈等接触应力的设计原则,确定了内、外圈沟曲率半径系数、径向游隙等应取较小值的设计原则。

Early Christian Iconography in Raphael’s Disputà

The theme of Raphael’s Disputàdel Sacramento(Disputation of the Holy Sacrament)has perplexed scholars over the years.Though the subject of theology has been mentioned,no one has shown in depth how the painting reflects theology or how the figures work together to present a unified theme on theology.Questions remain concerning the broader theological meaning of the Disputà.This study will reexamine the material and offer a deeper interpretation based on early Christian iconography and a study of figures from early Church history.From an early Christian point of view,it will be shown how the presence of specific figures in the Disputàexplain the Eucharistic tradition through apostolic succession since the time of the early Church.

Redebate on the Value of Chinese Characters

In order to deepen our rational understanding of Chinese characters,it is necessary to reexamine the value of it today.The reason why Chinese characters can keep vital is that it fits the unique thinking mode and aesthetic standards of the Han People.In the meantime,it intervenes in Chinese ontology by improving the resolution ratio of information trans,and objectively performs the function of the fourth element of language.

超大孔分子筛,十年再回顾

沸石分子筛是一类重要的具有明确孔道结构以及催化位点的结晶孔材料.但是由于其微孔开口的本质限制了其在大分子吸附与转化方面的应用.10年前,西班牙ITQ研究所的Corma教授、吉林大学于吉红教授以及本文通讯作者发表了一篇关于超大孔分子筛的历史回顾文章.该文从超大孔分子筛的合成、结构、假想结构以及催化性能等方面进行了综述.这一类材料填补了传统沸石分子筛和有序介孔材料之间的孔径缺口.在最近10年中,多种新型超大孔分子筛以及新颖的合成方法陆续被报道.本文对该方向近10年中的研究进行了综合评述.

基于ADORE的陀螺电机主轴承优化设计

基于ADORE建立轴承仿真模型对某型号陀螺电机主轴承进行动力学分析,分析了球数、内外圈沟道曲率半径系数、径向游隙等结构参数对轴承沟道最大接触应力、摩擦力矩、球磨损率、轴承疲劳寿命的影响。结果表明:选取较多的球数有利于改善轴承性能;选取较大的径向游隙有利于减小沟道最大接触应力,提高轴承寿命,降低轴承摩擦力矩和球磨损率;在满足轴承最大接触应力要求时,适当选取较大的内、外圈沟道曲率半径系数有利于降低轴承摩擦力矩和球磨损率。并以轴承摩擦力矩、球磨损率、轴承疲劳寿命为优化目标对轴承结构参数进行多目标优化设计,确定了最佳设计方案。