航天飞行器金属结构的制造工艺及检验方法研究

我国航天技术通过半个世纪的发展,已经迈向了世界.人们已经意识到航天飞行器在航天技术中发挥了重要作用,并且对其进行了积极的研究.在空间开发中航天飞行器发挥了主要作用,其已经成为航天高技术研究的重点.在这样的情况下,对航天飞行器金属结构的制造工艺和检测方法的研究具有重要意义.该文主要分析了航天飞行器的工艺特点和发展,飞行器结构件的数控加工技术,飞行器结构强度可靠性检验.     

浅谈20世纪以来航空航天科普散文创作

该文综述了航空和航天科普散文创作的历史.航空航天科普散文创作的开始与世界航空航天业的发展相比并不晚,问题是当时没有支持航空航天工业及其科学普及创作的工业基础.航空和航天科普作家试图告诉读者,航空航天是救国的方法之一.但受到读者地域和教育水平限制,航空航天科普散文创作的影响力仍然有限.1949年后,因为进口苏联国防工业,航空和航天工业迅速发展,航空和航天科普散文创作也随之发展.作家认为航空和航天工业是建设现代化的因素之一,航空航天科普散文创作使读者的科学知识也现代化.不过当时航空航天工业有保密性,也不太发达,科普写作多限于基本常识介绍和不成熟的想象.1980年以后,随着改革开放,航空和航天散文创作先于航空航天工业改变.写作更为开放,并介绍世界航空航天的知识.随着读者教育水平提高,形成了不同读者的市场.航空航天科普散文创作的风格也随市场发生了变化.航空航天科普主要读者的市场需要更专业的创作,作家也调整创作以适应市场.因为必须更专业化,文学元素减少了.     

FT-IR分析航天诱变育种番茄品系种子

本文首次采用傅立叶变换红外光谱法(FT-IR),对航天诱变育种番茄品系种子和系统法选育的番茄品系种子进行了对比研究,比较了它们红外光谱的异同。番茄种子的红外光谱主要由蛋白质的吸收带和碳水化合物的吸收带组成,经航空诱变后的番茄种子红外光谱的主要吸收峰的峰位、峰形与系统法选育的番茄种子基本相同,表明其主要成分和基本结构并未发生变化。发生变异的地方是:果实中维生素C和糖分含量显著增加的两份太空番茄种子,在1162cm-1~1099cm-1峰处的吸收均比两种普通种子的大。此外太空小番茄种子在1162cm-1峰处的吸收特别显著,表明经航空诱变后太空番茄种子中的碳水化合物的含量增加了。     

Reduced function and disassembled microtubules of cultured cardiomyocytes in spaceflight

Lack of gravity during spaceflight has profound effects on cardiovascular system, but little is known about how the cardiomyocytes respond to microgravity. In the present study, the effects of spaceflight on the structure and function of cultured cardiomyocytes were reported. The primary cultures of neonatal rat cardiomyocytes were carried on Shenzhou-6 spacecraft and activated at 4 h in orbit. 8 samples were fixed respectively at 4, 48 and 96 h after launching for immunofluorescence of cytoskeleton, and 2 samples remained unfixed to analyze contractile and secretory functions of the cultures. Ground samples were treated in our laboratory in parallel. After 115 h spaceflight, video recordings displayed that the number of spontaneous beating sites in flown samples decreased significantly, and the cells in the beating aggregate contracted in fast frequency without synchrony. Radioimmunoassay of the medium showed that the atrial natriuretic peptide secreted from flown cells reduced by 59.6%. Confocal images demonstrated the time-dependant disassembly of mirotubules versus unchanged distribution and organization of microfilaments. In conclusion, above results indicate reduced function and disorganized cytoskeleton of cardiomyocytes in spaceflight, which might provide some cellular basis for further investigations to probe into the mechanisms underlying space cardiovascular dysfunction.     

中国载人航天再谱新篇

2005年10月12日9时，举世瞩目的中国第二艘载人飞船——神舟六号，把费俊龙、聂海胜两名航天员送入太空，在太空飞行5天后于10月17日4时33分安全返回地面。神舟六号飞船以实现多人多天飞行为目标。搭载了载人航天第二步任务试验设备和科学试验设备，全面验证和考核了载人飞船的生命保障功能，以及结构与机构系统和制导导航与控制系统等。首次实现了“真正有人参与的空间飞行试验”，具有承上启下的重要意义，是我国载人航天工程“三步走”战略进入第二步任务的揭幕之战。     

拉利伯特：马戏团老板成下一位太空游客

俄罗斯联邦航天署载人航天项目主管克拉斯诺夫日前宣布．来自加拿大的亿万富翁盖·拉利伯特将于今年秋天乘坐俄“联盟TMA-16”载人飞船登上国际空间站,他的此次旅行还有一项特殊的社会使命,那就是呼吁全世界将水资源问题作为太空科研的一部分加以关注。     

微重力环境利用

文章阐述了微重力条件下的流体物理基本现象的研究,包括流体和体积输运,扩散与质量输运,毛细与润湿、固化、成核与过冷、临界现象以及学科的相关性。继之,简要介绍了微重力实际应用,包括：太空材料加工,各咱晶体生长,金属与合金、复合材料、玻璃等加工工艺;燃烧与微重力问题;生命科学中微重力利用问题（另文发表）。其间,顺便讨论了航天技术发展对微重力科学的推进与限制,针对我国卫星应用这个课题,以理论联系实际的方法进行分析评价。该文是对《微重力实验环境》一文（见１９９８年第７期《物理》）的补充。     

Design methods of rhombic tensegrity structures

As a special type of novel flexible structures, tensegrity holds promise for many potential applications in such fields as materials science, biomechanics, civil and aerospace engineering. Rhombic systems are an important class of tensegrity structures, in which each bar constitutes the longest diagonal of a rhombus of four strings. In this paper, we address the design methods of rhombic structures based on the idea that many tensegrity structures can be constructed by assembling one-bar elementary cells. By analyzing the properties of rhombic cells, we first develop two novel schemes, namely, direct enumeration scheme and cell-substitution scheme. In addition, a facile and efficient method is presented to integrate several rhombic systems into a larger tensegrity structure. To illustrate the applications of these methods, some novel rhombic tensegrity structures are constructed.     

最大地面风速的预测研究

为了解决航天发射场极值风速的预测问题,本文提出了用于极值风速预测的一种新方法－－相关系数法,并利用此方法对三种典型的概率分布进行了对比研究,在对比过程中,检验了三组极值风速,假设每组检验样本内的极值风速数据是统计独立的,于是极值风速就可以描述为随机过程,研究表明最适于描述极值风速的概率分布是reverse Weibull分布,与peak-over-threshold法所得出的结论具有良好的一致性。     

Periodic motions of spinning rigid spacecraft under influence of gravitational and magnetic fields

The motion of a magnetized axisymmetric spacecraft about its center of mass in a circular orbit is considered, taking the gravitational and magnetic effects of the central body into account. Equations of motion of the reduced system are transformed to equations of plane motion of a charged particle under the action of electric and magnetic fields. Stationary motions of the system are determined and periodic motions near to them are constructed using the Lyapounoff theorem of the holomorphic integral.