Calcium metabolism and the osteopenia of space flight

This paper briefly reviews the subject of bone remodelling and calcium homeostasis and considers the changes that occur in the microgravity environment of space. The effectiveness of exercise as a countermeasure to bone demineralisation is discussed.     

Food for thought--nutritional problems in space

The present paper discusses how the study of nutritional problems in space have proceeded, the way microgravity may alter nutritional requirements and how these may be met during long term missions in space.     

语声通讯硬件

本文介绍一个字长为16位的快速数字信号处理器。同其它系统不同的,这个处理器不使用位片式元件。但它却达到了比较高的性能(5M 指令/秒)。并具备类微外理机指令系统的简单编程。它通常连接在一个通用计算机上但它的输入/输出系统仍具备比较简单的实时能力。它从构造一个共振峰合成器和一个线性预测声码器的试验中已得到验证。     

Reassessing the possibility of life on venus: proposal for an astrobiology mission

With their similar size, chemical composition, and distance from the Sun, Venus and Earth may have shared a similar early history. Though surface conditions on Venus are now too extreme for life as we know it, it likely had abundant water and favorable conditions for life when the Sun was fainter early in the Solar System. Given the persistence of life under stabilizing selection in static environments, it is possible that life could exist in restricted environmental niches, where it may have retreated after conditions on the surface became untenable. High-pressure subsurface habitats with water in the supercritical liquid state could be a potential refugium, as could be the zone of dense cloud cover where thermoacidophilic life might have retreated. Technology based on the Stardust Mission to collect comet particles could readily be adapted for a pass through the appropriate cloud layer for sample collection and return to Earth.     

The observational case for Jupiter being a typical massive planet

We identify a subsample of the recently detected extrasolar planets that is minimally affected by the selection effects of the Doppler detection method. With a simple analysis we quantify trends in the surface density of this subsample in the period-Msin(i) plane. A modest extrapolation of these trends puts Jupiter in the most densely occupied region of this parameter space, thus indicating that Jupiter is a typical massive planet rather than an outlier. Our analysis suggests that Jupiter is more typical than indicated by previous analyses. For example, instead of MJup mass exoplanets being twice as common as 2 MJup exoplanets, we find they are three times as common.     

Adsorption water-related potential chemical and biological processes in the upper martian surface

Mars Odyssey has given strong evidence for the existence of water in the upper martian surface at equatorial latitudes. The water content, which corresponds to the hydrogen in the soil, can regionally reach values up to about 15%. This water is mainly in the form of structurally and partially irreversibly bound "crystal" water, and of reversibly bound and partially unfrozen adsorption water. This adsorption water, which has "liquid-like" properties as a two dimensional fluid or film, can trigger-in the presence of ultraviolet light and in concentrations similar to what has been measured on Mars-photocatalytic processes that are important for martian surface chemistry. The consequences of the diurnally variable presence of adsorption water on the chemistry and hypothetical biological processes at and in the upper martian surface at equatorial and mid-latitudes are discussed in terms of water-related environmental aspects for chemical and hypothetical life processes on Mars.     

飞行器围绕小行星的轨道运动

分析了飞行器围绕小行星轨道运动的特点，介绍了所建立的表述这一问题的理论基础。采用三种不同方法从几个侧面揭示了这一问题的本质特征。给出了所完成的研究这一问题的进展、结果和相互联系，其中包括轨道摄动、共振运动和周期轨道运动。这一问题的核心和难点是轨道的稳定性问题。     

设计一种性能评价系统的全面质量管理方法(英文)

本文在评价全面质量管理（Ｔｏｔａｌｑｕａｌｉｔｙｍａｎａｇｅ－ｍｅｎｔ,ＴＱＭ）的基础上,提出一种改进的性能评价系统（Ｐｅｒｆｏｒｍａｎｃｅａｐｐｒａｉｓａｌｓｙｓｔｅｍ,ＰＡＳ）。文中强调理解顾客（包括管理人员及雇员）对于ＰＡＳ的要求,从而突出简化该评价系统的基本要素及实施过程。经过改进的评价系统包括工作策划、审议及对个人、集体及管理人员所作的贡献进行评估。此外,将评估标准分为三类,这已成为方便大多数雇员有效的评价方法,同时给那些需要改进的个人以积极改进的余地。如果在全面质量管理中首先强调人的因素,那么人事体制也必须体现这一原则。