结构网格MWENO-7格式的构造和应用

在结构网格上构造了一种多重加权实质无波动激波捕捉格式,命名为MWENO-7(Multi-weighted essen-tially non-oscillatory)格式。提出了一种新的模板集上权的计算策略:通过探测因子来判断模板集上间断出现的位置,调节相应模板上的线性权,再与光滑因子结合起来得到非线性权,以保证在不出现伪振荡的前提下尽可能利用原有的等距模板构造出尽可能高阶的格式。文中给出几个典型算例,验证了MWENO-7格式的有效性。     

First results of PRECISE—Development of a MEMS-based monopropellant micro chemical propulsion system

PRECISE focuses on the research and development of a MEMS-based monopropellant micro chemical propulsion system for highly accurate attitude control of satellites. The availability of such propulsion systems forms the basis for defining new mission concepts such as formation flying and rendezvous manoeuvres. These concepts require propulsion systems for precise attitude and orbit control manoeuvrability. Application-oriented aspects are addressed by two end-users who are planning a formation flying mission for which the propulsion system is crucial. Basic research is conducted aiming at improving crucial MEMS technologies required for the propulsion system. Research and development also focuses on the efficiency and reliability of critical system components. System analysis tools are enhanced to complement the development stages. Finally, the propulsion system will be tested in a simulated space vacuum environment. These experiments will deliver data for the validation of the numerical models.     

Chandra imaging spectroscopy of the central region of AWM7

We report on the results of Chandra observations of the galaxy cluster AWM7. The ACIS image reveals new substructures with a spatial extent of more than 8″ (4 kpc at AWM7) near the cD galaxy center, represented by a hard sub-peak and a soft peak. These substructures suggest that a dynamical process related to the formation of the cD galaxy is now taking place. Inside the cluster core within a radius of 2′, annular spectra with every 10″ step are fitted well by single temperature models. The temperature gradually drops from 4.2 keV at a radius of 60 kpc (2′) to 1.8 keV at the cluster center. The radial abundance profile shows a gradient with a peak metallicity of 1.5 solar at a radius of about 15″ (7 kpc). A two-dimensional map shows two high metallicity blob-like regions, which may be the gas expelled from the cD galaxy.     

表面涂层破损对7 B04铝合金点蚀的影响及仿真研究

模拟7B04铝合金表面涂层破损,采用电化学试验研究7B04铝合金在不同环境条件下的自腐蚀与点蚀行为,基于电偶腐蚀数学模型,通过有限元法分析7B04铝合金与TA15钛合金接触后发生点蚀的条件。结果表明：7B04铝合金点蚀电位受Cl-浓度和pH值的影响,在NaCl质量分数>10%的中性溶液及NaCl质量分数为3.5%的酸性溶液中,自腐蚀状态下7B04铝合金即可发生点蚀;7B04铝合金与TA15钛合金接触后,电位升高,增加了发生点蚀的可能性,在NaCl质量分数为3.5%的中性溶液中,当阴阳极面积比≥40时,7B04铝合金发生点蚀的萌生并进一步扩展;7B04铝合金电位随阴阳极距离的增大而下降,但幅度有限,在10 m的距离内下降不超过2 mV。     

Present status of very high energy gamma ray observations

Recent results from observations of the southern sky objects are summarized. The unpulsed, persistent very high energy (VHE) emission from the gamma ray pulsars, the Crab and PSR1706-44, is discussed. A process of energetic electrons ejection may take place from a variety of other objects such as from X-ray binaries, similarly to the pulsars. Such an effect may be seen also in pair halos around extragalactic VHE gamma ray emitters, the observational study of which is still in a preliminary stage in the southern hemisphere.     

民用运输类飞机合格审定性能试飞方法研究

结合Y7－200A飞机型号合格审定试飞情况，对一般科目试飞、模拟冰型试飞及自然结冰试飞方法进行了研究及探讨。主要侧重于试飞方法的改进及对相关条款的理解，同时对试飞过程中遇到的难点及解决情况进行了介绍。所得结论为今后运输类飞机合格审定提供了借鉴，可供类似型号合格审定参考使用。     

激光熔覆Ni16Ti6Si7涂层组织与耐磨性

以Ni—Ti—Si合金粉末为原料，利用激光熔覆技术在0Cr18Ni9奥氏体不锈钢基材上制备了以Ni16Ti6Si7初生树枝晶和枝晶间γ-Fe—Ni固溶体组成的耐磨涂层。用光学显微镜、扫描电镜、透射电镜等对涂层组织进行了分析，测试了其在高温干滑动条件下的磨损性能。结果表明，由于Ni16Ti6Si7较高的硬度和具有较好韧性配合的涂层组织，激光熔覆涂层具有优异的高温磨损性能。     

基于ARM的嵌入式系统中FPGA配置方式研究

介绍了基于SRAM LUT结构的FPGA的几种在线配置方式,同时给出了在嵌入式系统中利用ARM7TDMI微处理器产生FPGA配置时序的方法;给出了最小系统应用电路;结合程序,分析如何产生FPGA的配置时序;本方案的实用性在本文得到充分说明.     

基于在轨温度测量数据的整星结构尺寸稳定性分析

针对高精度测绘卫星结构尺寸稳定性这一关键性问题，基于在轨温度测量数据，利用热分析模型和在轨温度变化规律，提出了卫星结构在轨温度场的反演方法。基于卫星结构在轨温度场反演数据，提出了针对载荷安装面法向夹角的拟合计算方法和夹角稳定性短期、长期指标的预示方法。根据该方法，给出了高分七号卫星在轨初期1个月内的结构稳定短期指标和长期指标预示结果，并对短期稳定性预示结果进行了统计分析。结果表明，各载荷安装面短期稳定性分析结果满足指标要求，相关分析方法可为同类航天器的结构热变形分析提供参考。     

高分七号卫星总体设计与技术创新

高分七号卫星(GF-7)是中国自主研制的首颗1∶1万比例尺立体测绘卫星, 是国家高分辨率对地观测系统重大专项的重要组成部分。卫星围绕“双线阵相机与激光测高仪主被动复合测绘”的新体制，形成了高精度内/外方位元素稳定性设计、高精度姿态稳定控制、首个X频段自适应高速率数据传输系统、星上智能星务管理系统等一系列关键技术和创新点，实现了少控制点或无控制点区域的大比例尺立体测绘能力。介绍了卫星的总体设计情况，总结了观测体制、高精度载荷、姿态控制、高速数传、智能星务等技术创新点，通过卫星在轨初步测试结果进行了评价，认为卫星能够满足1∶1万测绘任务的要求。