光电倍增管寿命试验研究与系统设计

光电倍增管(PMT)是空间光学探测应用的重要探测器件之一,由于制造工艺的限制,光电倍增管具有很强的个体差异性。设计了一套应用于星载激光大气探测雷达的光电倍增管寿命评估自动测试系统,并建立科学的测试方法与流程,通过对光电倍增管光电响应与暗电流等关键参数的试验、监测与分析,研究评估了其寿命特性。     

Initial design of laboratories for sustainable habitation

An effective and self-sustainable artificial habitat design is essential for human spaceflight and expansion of mankind into orbit or towards other celestial bodies. There are two approaches that need to be implemented in future sustainable habitats: the use of re-cycling technologies in order to gain experience in closed-loop processes and the primary production of resource materials using In Situ Resource Utilisation (ISRU) principles. Various products will be provided and, where applicable, recycled in such a system taking into account basic human factors requirements such as crew work load capacity, safety and well-being, namely:     

The water cycle in closed ecological systems: Perspectives from the Biosphere 2 and Laboratory Biosphere systems

To achieve sustainable, healthy closed ecological systems requires solutions to challenges of closing the water cycle – recycling wastewater/irrigation water/soil medium leachate and evaporated water and supplying water of required quality as needed for different needs within the facility. Engineering Biosphere 2, the first multi-biome closed ecological system within a total airtight footprint of 12,700 m² with a combined volume of 200,000 m³ with a total water capacity of some 6 × 10⁶ L of water was especially challenging because it included human inhabitants, their agricultural and technical systems, as well as five analogue ecosystems ranging from rainforest to desert, freshwater ecologies to saltwater systems like mangrove and mini-ocean coral reef ecosystems. By contrast, the Laboratory Biosphere – a small (40 m³ volume) soil-based plant growth facility with a footprint of 15 m² – is a very simplified system, but with similar challenges re salinity management and provision of water quality suitable for plant growth. In Biosphere 2, water needs included supplying potable water for people and domestic animals, irrigation water for a wide variety of food crops, and recycling and recovering soil nutrients from wastewater. In the wilderness biomes, providing adequately low salinity freshwater terrestrial ecosystems and maintaining appropriate salinity and pH in aquatic/marine ecosystems were challenges. The largest reservoirs in Biosphere 2 were the ocean/marsh with some 4 × 10⁶ L, soil with 1 to 2 × 10⁶ l, primary storage tank with 0 to 8 × 10⁵ L and storage tanks for condensate and soil leachate collection and mixing tanks with a capacity of 1.6 × 10⁵ L to supply irrigation for farm and wilderness ecosystems. Other reservoirs were far smaller – humidity in the atmosphere (2 × 10³ L), streams in the rainforest and savannah, and seasonal pools in the desert were orders of magnitude smaller (8 × 10⁴ L). Key technologies included condensation from humidity in the air handlers and from the glass space frame to produce high quality freshwater, wastewater treatment with constructed wetlands and desalination through reverse osmosis and flash evaporation were key to recycling water with appropriate quality throughout the Biosphere 2 facility. Wastewater from all human uses and the domestic animals in Biosphere 2 was treated and recycled through a series of constructed wetlands, which had hydraulic loading of 0.9–1.1 m³ day⁻¹ (240–290 gal d⁻¹). Plant production in the wetland treatment system produced 1210 kg dry weight of emergent and floating aquatic plant wetland which was used as fodder for the domestic animals while remaining nutrients/water was reused as part of the agricultural irrigation supply. There were pools of water with recycling times of days to weeks and others with far longer cycling times within Biosphere 2. By contrast, the Laboratory Biosphere with a total water reservoir of less than 500 L has far quicker cycling rapidity: for example, atmospheric residence time for water vapor was 5–20 min in the Laboratory Biosphere vs. 1–4 h in Biosphere 2, as compared with 9 days in the Earth’s biosphere. Just as in Biosphere 2, humidity in the Laboratory Biosphere amounts to a very small reservoir of water. The amount of water passing through the air in the course of a 12-h operational day is two orders of magnitude greater than the amount stored in the air. Thus, evaporation and condensation collection are vital parts of the recycle system just as in Biosphere 2. The water cycle and sustainable water recycling in closed ecological systems presents problems requiring further research – such as how to control buildup of salinity in materially closed ecosystems and effective ways to retain nutrients in optimal quantity and useable form for plant growth. These issues are common to all closed ecological systems of whatever size, including planet Earth’s biosphere and are relevant to a global environment facing increasing water shortages while maintaining water quality for human and ecosystem health. Modular biospheres offer a test bed where technical methods of resolving these problems can be tested for feasibility.     

面向大飞机项目全生命周期的产学研合作模式研究

基于全生命周期的视角,将大飞机的生命周期划分为3个主要的阶段:飞机研发设计阶段、飞机工程制造阶段、飞机商业运营阶段.对应提出了3种不同的产学研合作模式:企业大学共同创新的战略型合作模式、企业工程化主导的协同型合作模式；企业商业化主导的价值型合作模式.通过对这3种模式的剖析,以期为大飞机研制过程中产学研合作模式的选择提供理论支撑.     

Improvements in and actual performance of the Plant Experiment Unit onboard Kibo,the Japanese experiment module on the international space station

In 2004, Japan Aerospace Exploration Agency developed the engineered model of the Plant Experiment Unit and the Cell Biology Experiment Facility. The Plant Experiment Unit was designed to be installed in the Cell Biology Experiment Facility and to support the seed-to-seed life cycle experiment of Arabidopsis plants in space in the project named Space Seed. Ground-based experiments to test the Plant Experiment Unit showed that the unit needed further improvement of a system to control the water content of a seedbed using an infrared moisture analyzer and that it was difficult to keep the relative humidity inside the Plant Experiment Unit between 70 and 80% because the Cell Biology Experiment Facility had neither a ventilation system nor a dehumidifying system. Therefore, excess moisture inside the Cell Biology Experiment Facility was removed with desiccant bags containing calcium chloride. Eight flight models of the Plant Experiment Unit in which dry Arabidopsis seeds were fixed to the seedbed with gum arabic were launched to the International Space Station in the space shuttle STS-128 (17A) on August 28, 2009. Plant Experiment Unit were installed in the Cell Biology Experiment Facility with desiccant boxes, and then the Space Seed experiment was started in the Japanese Experiment Module, named Kibo, which was part of the International Space Station, on September 10, 2009 by watering the seedbed and terminated 2 months later on November 11, 2009. On April 19, 2010, the Arabidopsis plants harvested in Kibo were retrieved and brought back to Earth by the space shuttle mission STS-131 (19A). The present paper describes the Space Seed experiment with particular reference to the development of the Plant Experiment Unit and its actual performance in Kibo onboard the International Space Station. Downlinked images from Kibo showed that the seeds had started germinating 3 days after the initial watering. The plants continued growing, producing rosette leaves, inflorescence stems, flowers, and fruits in the Plant Experiment Unit. In addition, the senescence of rosette leaves was found to be delayed in microgravity.     

机务维修系统非例行维修平台的设计研究

非例行维修是航空公司机务维修方案的重要组成部分。由于非例行维修的不确定性,需要调研航空公司的业务流程和运行特点,分析具体的设计需求,开发出有效的现代化非例行维修管理平台。运用Delphi工具及Oracle数据库开发出航空公司非例行机务维修平台,以非单生命周期数据流转为核心,建立起航空公司对于非例行维修的管理平台,并介绍实现平台功能的几项关键技术。实际情况表明平台能够对航空公司的维修管理进行有效的控制,缩短维修时间,降低维修成本。     

飞船环控生保系统主要故障模型分析及飞控对策

研究了载人飞船环控生保系统主要故障模型及飞控对策，根据系统工作原理建立了影响飞行安全的主要故障模型，如舱体泄漏、气源消耗过量和CO2净化失效等，应用该类模型对飞行数据进行实时处理，判断或预测故障，同时给出飞控对策。该方法已成功应用于首次载人飞行。     

指数寿命型可靠性增长试验的Bayes分析

该文论述了指数寿命型可靠性增长试验中的Bayes分析方法。文中首先给出了可靠性分析的模型，然后运用历次阶段性试验中的可靠性增长数据建立动态参数模型，在此基础上给出各阶段可靠性增长试验中失效率的Bares估计。     

固体推进剂贮存可靠寿命的Monte Carlo仿真计算

用Monte carlo统计模拟方法对火箭发动机固体推进剂随环境温度变化的力学性能进行了分析,提出了力学性能的可靠寿命仿真计算的方法,并对延伸率的老化可靠寿命进行了计算。     

长寿命通信卫星的可靠性研究

通信（广播）卫星是典型的有长寿命要求的卫星。在广泛调查国内外通信卫星工程资料的基础上，考察了它们的轨道性能与寿命情况，并分析了影响卫星寿命和可靠性的因素，空间环境是影响卫星性能和寿命的一个重要因素。对为了避免和减少环境效应影响的工程方法进行了探究。结合工程实际问题研究了长寿命卫星的设计策略，并对需进一步研究的课题作了探索。