惯性顶级固体进推剂的研制与鉴定

本文介绍了惯性顶级(IUS)固体火箭发动机用的丁羟推进剂及推进剂/包复层/绝热层界而系统的研制情况及生产历程;介绍了根据发动机设计要求选择推进剂配方的情况和推进剂的主要性能;还介绍了研制期间对配方和工艺的某些小的修改及修改原因。本文亦讨论了推进剂/包复层/绝热层的界面系统,包括包复层化学的主要特性和控制迁移现象以提高粘结系统的完整性的方法。     

Artificial gravity--head movements during short-radius centrifugation: influence of cognitive effects

Short-radius centrifugation is a potential countermeasure against the effects of prolonged weightlessness. Head movements in a rotating environment, however, induce serious side effects: inappropriate vestibular ocular reflexes (VOR), body-tilt illusions and motion sickness induced by cross-coupled accelerations on a rotating platform. These are well predicted by a semicircular canal model. The present study investigates cognitive effects on the inappropriate VOR and the illusory sensations experienced by subjects rotating on a short-radius centrifuge (SRC). Subjects (N=19) were placed supine on a rotating horizontal bed with their head at the center of rotation. To investigate the extent to which they could control their sensations voluntarily, subjects were asked alternatively to "fight" (i.e. to try to resist and suppress) those sensations, or to "go" with (i.e. try to enhance or, at least, acquiesce in) them. The only significant effect on the VOR of this cognitive intervention was to diminish the time constant characterizing the decay of the nystagmus in subjects who had performed the "go" (rather than the "fight") trials. However, illusory sensations, as measured by reported subjective intensities, were significantly less intense during the "fight" than during the "go" trials. These measurements also verified an asymmetry in illusory sensation known from earlier experiments: the illusory sensations are greater when the head is rotated from right ear down (RED) to nose up (NU) posture than from NU to RED. The subjects habituated, modestly, to the rotation between their first and second sequences of trials, but showed no better (or worse) suppression of illusory sensations thereafter. No significant difference in habituation was observed between the "fight" and "go" trials.     

小型、低成本、P波段机载双极化合成孔径雷达的设计

Wageningen大学和婆罗洲猩猩生存基金会（BOS）希望用一种小型、低成本、P波段机载双极化合成孔径雷达监视印度尼西亚森林的生物群。本文介绍了一台此种雷达设计方面的初步研究情况。确定应用要求，并根据要求得到主要的雷达参数。本文还介绍了基于商用货架元件的系统的初步设计。系统的几点新颖之处是：采用直接数字合成进行调制、采用双极化微带方形贴片（patch）天线以及系统的尺寸和功耗都降低了等。为了有助于SAR系统的计算和比较，开发了基于通用Matlab的SARCAL程序。本文还将阐述其原理和主要功能。     

CASH 2021: commercial access and space habitation

Issues about commercialization of space have been a growing concern in the past decade for the space community. This paper focuses on the work from a team of 51 students attending the Summer Session Program of the International Space University in Bremen, Germany. CASH 2021 (Commercial Access and Space Habitation) documents a plan that identifies commercial opportunities for space utilization that will extend human presence in space, and will chart the way forward for the next 20 years. The group selected four commercial sectors that show the most promise for the future: tourism, entertainment, space system service, assembly and debris removal, and research and development/production. The content of this document presents the results of their research. Historical activities in each of the commercial sectors are reviewed along with the current market situation. To provide a coherent background for future commercialization possibilities a scenario has been developed. This scenario includes a postulated upon ideal future and includes social, political and economic factors that may affect the space industry over the timeline of the study. The study also presents a roadmap, within the limited optimistic scenario developed, for the successful commercialization of space leading to future human presence in space. A broad range of commercially viable opportunities, not only within the current limits of the International Space Station, but also among the many new developments that are expected by 2021 are discussed.     

Evaluation of bleomycin-induced chromosome aberrations under simulated microgravity conditions in human lymphocytes using "FISH" techniques

In the present investigation we report the effects of simulated microgravity conditions (clinostat) on the induction of chromosomal aberrations in human lymphocytes in vitro by (R) Bleomycin. Chromosomal aberrations have been analysed by means of fluorescent in situ hybridisation (FISH) and chromosome-specific composite DNA probes (chromosome painting). The results obtained show that, under simulated microgravity conditions, the levels of both symmetrical and asymmetrical (dicentrics, rings), the number of cells bearing "complex" aberrations and hence the total numbers of aberrations were significantly elevated at any of the dose-levels assayed, compared to the parallel treatments performed as 1g control ("ground"). Furthermore, the ratio symmetrical:asymmetrical translocations was markedly elevated under simulated microgravity conditions, compared to the findings usually observed under "normal" 1g conditions. On these bases, we are much inclined to believe that simulated microgravity, rather than limiting the resealing of DNA double strand breaks (DSB's) induced by genotoxic agents is influencing in terms of enhancement the misrejoining of DSB's which is actually responsible for the fixation of the original lesions to DNA into chromosomal aberrations. In addition, the possible different misrepair processes leading to the formation of symmetrical and asymmetrical translocations might be differentially influenced by microgravity being the symmetrical translocations significantly more represented.     

固体推进剂发动机的热贮存寿命

用概率计算方法计算了经受各种环境温度的固体推进剂火箭发动机的贮存寿命。在力学性能方面测定了粘弹效应、化学老化作用、累积损伤及统计变量。符号说明     

关于无源铷频标中光漂移和缓冲气体漂移问题

本文报道了无源铷频标中光漂移和缓冲气体漂移的计算和测量结果。光漂移是以两种接法,即分立滤光器法和集成滤光器法进行测量的。文章介绍一种能够恰如其份地描述所得结果的唯象分析方法,报道了不同的纯净缓冲气体或混合缓冲气体引起的频率漂移的测量结果,评述了频率与温度的非线性关系,将所得结果跟从前发表的数据做了比较,并且利用二次温度方程式进行简明分析,以进一步对这些结果加以说明。     

Search for the OH (X(2)Pi) Meinel band emission in meteors as a tracer of mineral water in comets: detection of N(2)(+) (A-X)

We report the discovery of the N(2)(+) A-X Meinel band in the 780-840 nm meteor emission from two Leonid meteoroids that were ejected less than 1000 years ago by comet 55P/Tempel-Tuttle. Our analysis indicates that the N(2)(+) molecule is at least an order of magnitude less abundant than expected, possibly as a result of charge transfer reactions with meteoric metal atoms. This new band was found while searching for rovibrational transitions in the X(2)Pi electronic ground state of OH (the OH Meinel band), a potential tracer of water bound to minerals in cometary matter. The electronic A-X transition of OH has been identified in other Leonid meteors. We did not detect this OH Meinel band, which implies that the excited A state is not populated by thermal excitation but by a mechanism that directly produces OH in low vibrational levels of the excited A(2)Sigma state. Ultraviolet dissociation of atmospheric or meteoric water vapor is such a mechanism, as is the possible combustion of meteoric organics.     

Automation and Robotics for Human Mars Exploration (AROMA)

Automation and Robotics (A&R) systems are a key technology for Mars exploration. All over the world initiatives in this field aim at developing new A&R systems and technologies for planetary surface exploration. From December 2000 to February 2002 Kayser-Threde GmbH, Munich, Germany lead a study called AROMA (Automation and Robotics for Human Mars Exploration) under ESA contract in order to define a reference architecture of A&R elements in support of a human Mars exploration program. One of the goals of this effort is to initiate new developments and to maintain the competitiveness of European industry within this field.