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21.
《Ceramics International》2022,48(2):1844-1850
Thermal protection materials with excellent thermal insulation properties and high reliability are crucial for aerospace vehicle. Mullite fiber insulation tiles coated with MoSi2-borosilicate glass (MFIT@MoSi2) were prepared by a simple slurry method. Results shown that the surface temperature rapidly reached 1043.1 °C under the heat flux of 450 kW/m2, while the cold-surface remained at room temperature. The adjusting effects of MoSi2-based coating on the thermal response and transfer properties of MFIT were investigated systematically. Compared with MFIT, the surface and internal temperatures of MFIT@MoSi2 were obviously suppressed, due to the existence of MoSi2-based coating with high emissivity, which effectively enhanced the thermal radiation of the surfaces. Finally, the structural reliability under coupled environment of heating (q0 = 450 kW/m2) and random vibration with high magnitude (20–2000 Hz, Grms = 20 g) was also investigated. Destructive cracking and peeling of the coating were not observed, due to the excellent bonding strength between the coating and the substrate. The results provided an important basis for the potential application of insulation tiles with mullite fibers in aerospace vehicles and the design of lightweight thermal protection systems. 相似文献
22.
《Ergonomics》2012,55(3):606-615
Abstract With the subject matter of ergonomics increasingly broadly conceived, a need is suggested for the systematization and codification of cultural influences on the wide-ranging elements of the field. Pertinent types of systematic analysis, basic and applied research, and training are viewed as necessary, both (a) to generate new knowledge, and (b) to develop culturally appropriate user applications that are important for varied work environments world-wide. 相似文献
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The morphing skin is the surface of a deployable frame which can change its shape to present optimal performance in all stages of a task for an aerospace vehicle. This article proposes a deployable frame with low kinematic error and high stability. Mechanical design and optimization of the deployable mechanism are developed, and specifically the analysis model of the deployable mechanism is established by the use of extendable units. The genetic algorithm is employed to find the optimal geometric parameters of the foldable structure. Furthermore, the design method of a bistable compliant mechanism is investigated to achieve the bistability. An example of a morphing leading edge (MLE) is analysed using the proposed method. The results show that the position errors converge to the optimal solution which supplies the minimum value. Numerical analysis indicates that the mechanism can provide two bistable positions for the actual use of the MLE. 相似文献
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罗益锋 《高科技纤维与应用》2014,39(5):1-8
就航天、航空、大型海水淡化装置和深海采油平台所需的关键先进材料及其部件的发展趋势和应用进展作概要的介绍。表明高端装备特别是航空航天和海洋开发利用,是一项复杂的系统工程,需要各种高技术、新材料部件、传感器和大量资金的支撑。指出高性能纤维及其复合材料在高端装备制造中不仅能满足高性能和轻量化要求,对节能减排也有重要贡献,对发展现代国防有极其重要的意义和作用,国家应予大力支持。 相似文献
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To simulate the ice accretion on an airfoil, a boundary moving technique is proposed to deal with the distortion of the airfoil surface due to ice accretion on the leading edge. Incorporating the two‐phase model of air‐supercooled droplets in the Eulerian coordinate system, this technique is applied to simulate the process of the rime ice accretion (the droplets freeze at the instant impinging on the airfoil) on the NACA 0012 airfoil, and the ice profile after ice accretion is achieved successfully. A brief comparison between the results of this paper and the experiment data indicates that the current method is applicable and effective. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(4): 226–234, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20064 相似文献
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对分布在不同城市的跨场区航天数据网而言,依托航天骨干网构建各分站内部私有专用网络是迫切所需。将MPLS-VPN(多协议标签交换虚拟专用网),多层标签技术应用到航天数据网中,达到高速转发业务数据和增强其稳定性及安全性。介绍MPLS-VPN的原理及关键技术,结合跨场区航天数据网建设的现状提出一组MPLS-VPN航天数据网结构,分析使用MPLS-VPN实现组网的部署情况,并且实验仿真跨场区航天数据网的组网环境。用2种常用的用户业务数据为场景,通过测试网络的性能指标,验证了采用MPLS-VPN架构方案的优点。 相似文献
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