航天器迎风面不同位置原子氧掏蚀效应的数值模拟研究

Kapton作为基底的热控涂层被广泛应用于航天器的外表层设计中。近地轨道航天器的飞行方向与航天器表面法线之间的夹角(在本文中简称为ANI)对原子氧掏蚀效应有较大的影响。文章利用Monte Carlo方法研究了航天器迎风面(即0°≤ANI≤90°处)上ANI与掏蚀效应之间的关系。结果表明,束流和撞击能量不变时,ANI的增加会引起原子氧掏蚀空腔发生同向倾斜,空腔的深度不断减小,而宽度将急剧增加;当保护层厚度一定时,ANI的增加还会引起缺陷处入射的原子氧的反应率降低。     

系部教学管理工作的探索与实践

系部教学管理工作决定系部各专业教学计划实施效果、教学任务落实情况以及教学质量的好坏。因此,研究系部教学管理,对于高职高专院校的教学工作是十分重要的。教学管理工作研究一是明确系部教学管理工作的任务及功能;二是教学计划的实施与监控;三是教学质量保证与教学改革;四是教师队伍的建设与管理。     

注重学练结合提高培养质量—关于高职高专第二课堂学练结合的研究与实践

高职高专第二课堂学练结合是在校学生实践教学的重要环节，通过对第二课堂学练结合的作用、方法、实施的途径及结果进行的研究与实践，学练结合，不仅是理论与实践相结合的一种方式，也是激发学生学习兴趣的一种方法，更是提高学生技能增长、拓展知识层面的有效手段。     

FIP Fractionation: Theory

In this review, the main models of ion-neutral frationation leading to an enhancement of the low FIP to high FIP abundance ratio in the corona or in the solar wind, are presented. Models based on diffusion parallel to the magnetic field are discussed; they are highly dependent on the boundary conditions. The magnetic field, that naturally separates ions from neutrals moving perpendicular to the field lines direction, when the ion-neutral frequency becomes lower than the ion gyrofrequency, is expected to play an active role in the ion-neutral separation. It is then suggested that ion-neutral fractionation is linked to the formation of the solar chromosphere, i.e. in magnetic flux-tubes at a temperature between 4000 and 6000 K. This revised version was published online in June 2006 with corrections to the Cover Date.     

航天器项目群管理模式探讨

阐述了我国现有航天器多项目管理的模式和特点,在分析我国航天器项目管理发展基础上,根据航天器研制任务急剧增长的情况提出了项目群管理的概念和项目群管理模式的思路,为寻找更好的适合航天器快速发展的项目管理方法提供参考。     

加强学科综合教学培养实际应用技能--《机械制图》中零件表面粗糙度综合教学法探讨

以机械制图课程中零件表面粗糙度为例，进行了学科综合教学法探讨，提出了新时期高等职业技术教育培养学生的新观点，学习贵以致用，应用综合知识，解决实际问题，提高高职技术人才应用技能。     

基于现实飞行条件下的飞行员英语陆空通话教学研究

本文首先提出目前飞行员英语陆空通话课堂教学中存在的问题和不足，在此基础上，结合具体事例说明了实际通话中飞行员用语失误或误解所造成的飞行事故，强调了实际飞行条件下飞行员英语陆空通话综合能力提高的必要性和迫切性。最后分析并提出了飞行员英语陆空通话课堂教学方法改进的新举措。     

大学英语大班教学方法探索

大班教学已是我国大学英语公共外语教学的普遍形式,而班级规模的扩大给英语教学带来了许多新的问题。为了培养合格的英语人才,适应新形势下社会的需求,详细地、有针对性地做了一系列研究,提出解决的对策和建议。     

No significant level of inheritable interchromosomal aberrations in the progeny of bystander primary human fibroblasts after alpha particle irradiation

A major concern for bystander effects is the probability that normal healthy cells adjacent to the irradiated cells become genomically unstable and undergo further carcinogenesis after therapeutic irradiation or space mission where astronauts are exposed to low dose of heavy ions. Genomic instability is a hallmark of cancer cells. In the present study, two irradiation protocols were performed in order to ensure pure populations of bystander cells and the genomic instability in their progeny were investigated. After irradiation, chromosomal aberrations of cells were analyzed at designated time points using G₂ phase premature chromosome condensation (G₂-PCC) coupled with Giemsa staining and with multiplex fluorescent in situ hybridization (mFISH). Our Giemsa staining assay demonstrated that elevated yields of chromatid breaks were induced in the progeny of pure bystander primary fibroblasts up to 20 days after irradiation. mFISH assay showed no significant level of inheritable interchromosomal aberrations were induced in the progeny of the bystander cell groups, while the fractions of gross aberrations (chromatid breaks or chromosomal breaks) significantly increased in some bystander cell groups. These results suggest that genomic instability occurred in the progeny of the irradiation associated bystander normal fibroblasts exclude the inheritable interchromosomal aberration.     

调频连续波无线电高度表的仿真研究

阐述了调频连续波无线电高度表工作原理和仿真模型，在分析中考虑了垂直速度形成的多普勒效应，文中给出几种仿真计算的结果，分析计算结果可得知高度表的工作稳定性以及多普勒效应引起的动态误差，仿真计算程序可以应用于优化伺服系统参量或制作高度表的数学仿真器等方面。