Development of a ground-based space micro-algae photo-bioreactor

The purpose of the research is to develop a photo-bioreactor which may produce algae protein and oxygen for future astronauts in comparatively long-term exploration, and remove carbon dioxide in a controlled ecological life support system. Based on technical parameters and performance requirements, the project planning, design drafting, and manufacture were conducted. Finally, a demonstration test for producing algae was done. Its productivity for micro-algae and performance of the photo-bioreactor were evaluated. The facility has nine subsystems, including the reactor, the illuminating unit, the carbon dioxide (CO₂) production unit and oxygen (O₂) generation unit, etc. The demonstration results showed that the facility worked well, and the parameters, such as energy consumption, volume, and productivity for algae, met with the design requirement. The density of algae in the photo-bioreactor increased from 0.174 g (dry weight) L⁻¹ to 4.064 g (dry weight) L⁻¹ after 7 days growth. The principle of providing CO₂ in the photo-bioreactor for algae and removing O₂ from the culture medium was suitable for the demand of space conditions. The facility has reasonable technical indices, and smooth and dependable performances.     

从中国电子商务发展现状浅析其存在问题

通过对电子商务的基本概念以及发展状况的简要介绍 ,结合电子商务自身的特点 ,客观分析了现阶段在中国的电子商务发展过程中存在于技术、管理和安全等方面的一些问题 ,以及制约我国电子商务发展的主要因素     

Development cost prediction of general aviation aircraft projects with parametric modeling

The study of the development cost of general aviation aircraft is limited by small samples with many cost-driven factors. This paper investigates a parametric modeling method for prediction of the development cost of general aviation aircraft. The proposed technique depends on some principal components, acquired by utilizing P value analysis and gray correlation analysis. According to these principal components, the corresponding linear regression and BP neural network models are established respectively. The feasibility and accuracy of the P value analysis are verified by comparing results of model fitting and prediction. A sensitivity analysis related to model precision and suitability is discussed in detail. Results obtained in this study show that the proposed method not only has a certain degree of versatility, but also provides a preliminary prediction of the development cost of general aviation aircraft.     

月球探测技术--发展历程和特点

介绍了人类发射月球探测器进行的主要探月活动以及月球探测技术的发展和演变。分析了月球探测轨道设计与地球卫星的区别 ,给出了一些最基本的设计原则。最后 ,对探测器总体系统设计中的构型技术和各分系统的特点及其设计要求作了描述     

降落伞的计算机仿真研究

降落伞是一种应用广泛的气动力减速装置，其试验费用在整个开发、研制费用中，占有很大的比例。如何节省这笔费用，运用计算机仿真技术无疑是个最佳办法和途径。文章总结了降落伞仿真的一些情况和降落伞仿真所遇到的关键技术，并提出了在降落伞仿真中所面临的主要问题及解决这些问题的一般方法，可为降落伞研究提供参考。     

宽带微波检波器的研制

宽频带晶体检波器采用混合集成工艺，用热压键合的方法把低势垒肖特基检波二极管的管芯焊接在微带电路上。整个电路制作在一个４ｍｍ×１２ｍｍ×０．３ｍｍ的三氧化二铝陶瓷基片上，并安装在一个圆柱型８．５ｍｍ×３５ｍｍ金属盒体内。射频联接应用ＳＭＡ接头，配有ＳＭＡ—Ｎ型转换接头。为了获得平坦的频率响应和低的输入驻波比，采用了一个Ｒ—Ｌ并联支路和“Ｔ”型匹配网络，从而使检波器在０．０１～１８ＧＨＺ频带内驻波比＜１．５，频率响应起伏＜±０．５ｄＢ，采用的Ｒ—Ｌ并联支路和“Ｔ”型网络亦可用于其它微波电路，以改善微波部件的性能。     

飞行器回收技术在新型号研制中的应用

文章简迷了飞行器回收技术在新型号研制中的应用情况,介绍了战略和战术武器及助推器具体的应用事例,说明飞行器回收技术在型号研制过程中的作用及意义。     

砷化镓太阳电池技术的进展与前景

介绍了砷化镓(GaAs)太阳电池的特点，并比较了液相外延(LPE)和金属有机物化学气相沉积(MOCVD)两种外延生长技术。叙述了国外单结、双结与三结GaAs太阳电池的结构、性能、研制及生产情况，分析了GaAs太阳电池的发展方向。最后根据国内GaAs太阳电池的研制进展和空间试用情况，提出了发展我国GaAs太阳电池的设想和建议。     

引信目标RCS理论算法的发展及应用

论述了引信近场雷达散射截面(RCS)计算的特殊性及难点，同时介绍了计算引信目标RCS的多种高频理论预估方法，着重比较了物理光学面元法与几何光学法，并讨论了其他一些理论方法的特点。通过某型导弹的应用实例，指出了引信目标模型在雷达引信目标系统仿真中的重要作用。     

高职院校高等数学教学探索与改革

论述了高职院校高等数学教育的现状，传统的高职高等数学教育已跟不上时代的步伐。提出高职院校高等数学教学改革的主要内容是：将传统与现代教学手段相结合；加强师生间的沟通；培养学生对学习高等数学的兴趣和分析问题、解决问题的能力；柘宽视野，提高学生的数学素养。