Transient Modeling of Synchronous Machine-Transformer-SCR Bridge

A rigorous mathematical model of a synchronouschine-machine-transformer-thyristor bridge unit is presented in state-space form with coefficients that are explicit functions of standard parameters. The developed model has a minimum order for each of the various operation modes of the bridge, and its form is such that it can be readily interfaced with any type of dc network connected to the bridge. In addition, the model has the capability to consider different types of transformer winding connections. In a digital simulation, the explicit form of the state model eliminates the need of matrix inversions at each integration step. This and the use of the ?, ? reference frame result in a high computing efficiency and accuracy. As an illustration, simulation results are shown of a case study where the unit is part of a high-power pulse generating system.     

SPR生物传感器在生命科学及在航天医学中的应用

表面等离子体共振生物传感器在分析生物分子相互作用方面，具有灵敏度高、实时在线、简单快捷和抗干扰能力强等优点，被广泛应用于临床检验、药物筛选等研究领域；因其能满足空间特殊环境下的使用要求，在航天医学领域具有广阔的应用前景．本文综述了表面等离子体共振生物传感器的原理、特点、在生命科学研究中的应用及在航天医学中的应用前景．     

编队飞行卫星群构型保持及初始化

导出了基于相对轨道要素的编队飞行卫星群轨道相对运动控制的轨道机动方程；提出了编队飞行卫星群轨道相对运动控制的轨道机动控制策略，利用不同方向的脉冲控制相对运动的轨道参数，包括轨道平面内机动和轨道平面外机动控制。根据相对轨道要素的变轨机动控制，进行编队飞行卫星群构型的初始化。这样的构型初始化可以视作一次特殊的变轨机动控制，很容易实现编队飞行构型的初始化机动。     

MSG-3在民用航空器维修大纲制定中的应用

国内民用航空器的研发起步较晚,目前投入运行的国产航空器型号种类和数量都不多,航空器制造厂家在制定维修大纲方面的经验较少.本文对国际上通行的MSG-3维修任务分析方法进行研究,首先介绍MSG-3维修任务分析方法产生和发展的历史背景,以及其在国内民机型号中的应用;然后详细叙述MSG-3维修任务分析方法(包括航空器系统、动力装置维修任务的分析方法,结构检查和区域检查任务的分析方法,以及形成维修大纲的流程和维修任务的后期优化);最后通过对航空器型号的审查经验,总结我国民用航空器制造厂家在制定航空器维修大纲时存在的问题和改进方向.     

ESA developments in life support technology: achievements and future priorities.

Following an enthusiastic start in 1985, ESA's life support technology development programme was re-assessed in the mid- to late-1990s to reflect the strong reduction in European manned space ambitions which occurred at that time. Further development was essentially restricted to activities that could constitute ISS upgrades or enhancements, or support ISS utilisation/operations, together with a single, limited, activity (MELISSA) aimed at bioregenerative life support, in the continuing hope that there might be "life after Station". The paper describes the current status of these activities and summarises the main priorities for future development that were identified at the April 1999 Workshop on Advanced Life Support.     

Radio fine structures in dm–cm wavelength range associated with magnetic reconnection processes

Radio bursts with fine structures in decimetric–centimetric wave range are generally believed to manifest the primary energy release process during flare/CME events. By spectropolarimeters in 1–2 GHz, 2.6–3.8 GHz, and 5.2–7.6 GHz at NAOC/Huairou with very high temporal (1.25–8 ms) and spectral (4–20 MHz) resolutions, the zebra patterns, spikes, and new types of radio fine structures with mixed frequency drift features are observed during several significant flare/CME events. In this paper we will discuss the occurrence of radio fine structures during the impulsive phase of flares and/or CME initiations, which may be connected to the magnetic reconnection processes.     

民用飞机复合材料结构制造工艺变化的等效性验证

高性能复合材料已经大量应用于民用运输飞机结构,并以飞机主制造商协同供应商的方式进行复合材料飞机结构的制造。介绍了航空器适航审定对复合材料结构制造的适航要求,引出了复合材料结构制造工艺变化的等效性验证方法。目前,复合材料结构制造工艺变化的等效性验证是通过所制造复合材料物理的、化学和基本力学的性能试验,并对试验结果进行统计分析来实现的。最后提供了等效性验证的接受准则。所述内容,对国内民用飞机复合材料结构在不同供应商处制造以及制造过程中工艺变化如何满足航空器适航审定要求提供借鉴;对其它行业复合材料结构制造的质量控制也有借鉴意义。     

Stability analysis of an aeroelastic system with friction

In this paper, harmonic balance method, exact formulation and numerical simulation method are adopted to study the effects of different friction stiffness on the stability of 1.5 degrees of freedom aeroelastic system. On this basis, the expressions of input energy and dissipated energy are deduced, and the energy method is used to reveal the mechanisms of the stable boundary and unstable boundary existing in the system and the effects of different friction stiffness on the stability of the system. Studies have shown that the stability region and the critical aerodynamic damping ratio of the system rise with the increase of the friction stiffness, while the friction stiffness has little effect on the stability boundary. In the analysis of the stability of system, the results of harmonic balance method, exact formulation and Newmark of numerical simulation method are in good agreement. Compared with exact formulation and numerical simulation method, the concept and conclusion of harmonic balance method are simple in the system stability analysis.     

航天飞行器中舷窗温度场及换热的研究：外部界面处于第三类非线性边界条件

本文采用控制容积法,光线踪迹法结合谱带模型,研究航天飞机返回大气层时舷窗硅玻璃的非稳态复合换热。文章给出了界面S_2处于第三类非线性边界条件下,舷窗硅玻璃内部的温度场和进入机舱内部的热流密度。计算结果表明,如不考虑硅玻璃内部的辐射作用,对温度场影响不太大,但对进入机舱内的热流密度将会产生很大的误差。     

用高速纹影摄影技术观测自由面微物质的喷射

本文介绍了适于爆轰实验研究的透射式高速纹影仪。该设备具有较高的测试灵敏度。应用它观测了铅和钢样品自由面的微物质喷射现象,取得了好的结果。