后抛质量加降落伞弹头回收方案及其应用

文章介绍了用后抛质量加降落伞方法回收弹头的原理以及在飞行试验和实际应用中的情况。     

浅说洲际导弹弹头的回收

文章概述了洲际导弹弹头回收的作用,比较了它与卫星回收的不同特点。介绍了弹头回收减速的几种基本方法和原理。     

航天器回收着陆技术

文章简叙了航天器回收着陆技术的发展过程,介绍了各种航天器的回收方法和航天回收系统的特点及工作原理。     

Silicifying biofilm exopolymers on a hot-spring microstromatolite: templating nanometer-thick laminae

Exopolymeric substances (EPS) are an integral component of microbial biofilms; however, few studies have addressed their silicification and preservation in hot-spring deposits. Through comparative analyses with the use of a range of microscopy techniques, we identified abundant EPS significant to the textural development of spicular, microstromatolitic, siliceous sinter at Champagne Pool, Waiotapu, New Zealand. Examination of biofilms coating sinter surfaces by confocal laser scanning microscopy (CLSM), environmental scanning electron microscopy (ESEM), cryo-scanning electron microscopy (cryo-SEM), and transmission electron microscopy (TEM) revealed contraction of the gelatinous EPS matrix into films (approximately 10 nm thick) or fibrillar structures, which is common in conventional SEM analyses and analogous to products of naturally occurring desiccation. Silicification of fibrillar EPS contributed to the formation of filamentous sinter. Matrix surfaces or dehydrated films templated sinter laminae (nanometers to microns thick) that, in places, preserved fenestral voids beneath. Laminae of similar thickness are, in general, common to spicular geyserites. This is the first report to demonstrate EPS templation of siliceous stromatolite laminae. Considering the ubiquity of biofilms on surfaces in hot-spring environments, EPS silicification studies are likely to be important to a better understanding of the origins of laminae in other modern and ancient stromatolitic sinters, and EPS potentially may serve as biosignatures in extraterrestrial rocks.     

基于LS-DYNA软件的降落伞充气过程仿真研究

文章基于LS-DYNA软件对降落伞的充气过程进行了数值模拟,得到了降落伞的充气时间和投影面积变化的规律,验证了使用LS-DYNA软件数值模拟降落伞充气过程的可行性,提出了一种新的数值模拟降落伞充气过程的分析方法。     

典型采样返回探测器的进入减速着陆系统分析

通过对典型的采样返回探测器（星尘号和起源号）的研究分析,总结归纳了采样返回探测器进入减速着陆系统的特点,特别是对探测器的气动外形布局、返回轨道设计、防热材料选择、降落伞系统设计等进行了分析,可以为下一步开展月球采样返回任务提供一定的参考。     

用全球定位系统信号的卡尔曼滤波技术测定宇宙飞船姿态

本文描述了利用全球定位系统信号测定低地球轨道定宙飞船三轴姿 态的系统。     

Effect of temperature on the adsorption of adenine

Equilibrium adsorption isotherms for the purine base adenine on the surface of graphite crystals have been obtained at 30, 40, 50, and 60 degrees C by frontal analysis using water as a mobile phase. These data were fitted to the Langmuir isotherm model and interpreted in terms of the well-characterized adsorbate monolayer structure. A van't Hoff plot was used to estimate the adsorption enthalpy, -delta H degree which we determined to be 20 kJ mol-1. The susceptibility of nucleic acid bases to aqueous-phase hydrolysis may have been a limiting feature for their inclusion in the primordial genetic architecture; our results suggest that the effects of temperature and the presence of inorganic solids must also be included when assessing the prebiotic availability of adenine.