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The scientific community has long embraced the concept of globalized collaboration, recognizing that scientific inquiry knows no borders and that scientific theory transcends nationality. With respect to translating scientific and technological innovation into practical application, however, national, political, and ideological barriers suddenly arise. At a time when the worlds of economics and finance are rapidly globalizing, the world of applied science lags behind — despite increasingly urgent need for global energy solutions. In the context of considering space solar power (SSP) systems, the author contends that these solutions require new ways of determining costs and benefits; that scientific experts should seek active engagement in the policy arena; and that SSP's scientific community has a critical role to play in advocating for consideration of space-based energy solutions. 相似文献
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地基模拟空间碎片速度测试技术 总被引:1,自引:1,他引:0
碎片速度测试技术是地基空间碎片模拟设备系统中的一项关键技术。文章对于毫米尺寸碎片的测速技术,介绍了电探针方法、激光遮断法、磁感应方法、X闪光照相以及激光干涉测速技术(VISAR)等;压电传感器方法、超高速条文摄影法及散射光法等微米级碎片,测速方法。通过介绍这些测速方法的基本原理及应用范围,并对相应的系统性能进行评价,可以为相关研究提供参考。另外,对常用的毫米和微米级空间碎片的地基驱动设备及其技术参数也进行了介绍。 相似文献
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Mark Nelson W.F. DempsterJ.P. Allen 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
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. 相似文献
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V-22“鱼鹰”倾转旋翼机研制历程与关键技术 总被引:1,自引:0,他引:1
倾转旋翼机具有速度快、噪声小、航程远、载重大和耗油率低等优点,本文介绍了贝尔直升机公司V-22"鱼鹰"倾转旋翼机从原理验证阶段的XV-3机到方案验证阶段的XV-15机,再到实用工程研制阶段的V-22"鱼鹰"机循序渐进的研制历程,并叙述了倾转旋翼机研制中的几项关键技术。 相似文献
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在分析航天制造技术的重要作用及特征的基础上,总结了我国航天制造技术发展取得的成绩,剖析了现存在的主要问题,结合我国航天事业发展的需要,提出了发展航天制造技术需要重点采取的对策。 相似文献
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本文简要介绍了中国燃气涡轮研究院在先进涡扇发动机空气系统与零件传热设计技术验证方面的研究情况,内容涉及发动机空气系统设计技术、零件热分析设计技术、涡轮叶片冷却设计技术及新型铸冷双层壳型高效涡轮冷却叶片设计中的关键技术。探讨了空气系统与零件传热设计技术中的设计计算方法、设计软件校核与改进、试验研究与参数测试、以及设计体系建设等问题,通过系统的模型、部件和发动机整机三个层次的试验验证,初步形成了空气系统与零件传热设计体系。 相似文献
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总结了国内外变循环涡扇冲压组合发动机的发展现状,对比分析了有/无能量传递构型的变循环涡扇冲压组合发动机的工作原理及优缺点。提炼了变循环涡扇冲压组合发动机的关键技术,包括总体性能仿真技术、高速宽工况风扇设计技术、加力/冲压燃烧室设计技术、热管理系统设计技术以及模态转换设计技术。基于国内需求和相关技术研究现状,给出了变循环涡扇冲压组合发动机后续重点研究方向的建议,包括发动机总体性能设计与仿真工具、发动机多设计点多学科耦合设计方法、发动机热管理系统设计与仿真建模以及关键部件的设计与试验。 相似文献