Autonomous navigation of Mars probe using X-ray pulsars: Modeling and results

Autonomous navigation of Mars probe is a main challenge due to the lack of dense ground tracking network measurements. In this paper, autonomous navigation of the Mars probe Orbits is investigated using the X-ray pulsars. A group of X-ray pulsars with high ranging accuracy are selected based on their properties and an adaptive extended Kalman filter is developed to incorporate the Mars probe dynamics and pulsar-based ranging measurements. Results of numerical experiment show that the three-dimensional positioning accuracy can achieve 750m in X-axis, 220m in Y-axis and 230m in Z-axis, which is much better than the positioning results by current Very Long Baseline Interferometry (VLBI) or Doppler observations with the accuracy of 150 km or several kilometers, respectively.     

预估构件裂纹扩展寿命的封闭解法及其在起落架中之应用

本文以Matsuoka模型为基础,以航空上常见的短周期加载为条件,导出了预估构件的裂纹扩展寿命的解析表达式 式中,α、β和γ分别为裂纹扩展速率Walker公式的系数与指数,n=β+γ,p是每一个加载周期中的程序块数,N_i为第i个程序块中加载次数,Z（α）是应力强度因于的几何因子。 我们采用本方法对某机前起落架剩余寿命试验的破坏部位寿命进行了预估,试验表明:计算结果比试验结果低18％。     

An equivalent ground thermal test method for single-phase fluid loop space radiator

Thermal vacuum test is widely used for the ground validation of spacecraft thermal control system. However, the conduction and convection can be simulated in normal ground pressure environment completely. By the employment of pumped fluid loops’ thermal control technology on spacecraft, conduction and convection become the main heat transfer behavior between radiator and inside cabin. As long as the heat transfer behavior between radiator and outer space can be equivalently simulated in normal pressure, the thermal vacuum test can be substituted by the normal ground pressure thermal test. In this paper, an equivalent normal pressure thermal test method for the spacecraft single-phase fluid loop radiator is proposed. The heat radiation between radiator and outer space has been equivalently simulated by combination of a group of refrigerators and thermal electrical cooler(TEC) array. By adjusting the heat rejection of each device, the relationship between heat flux and surface temperature of the radiator can be maintained. To verify this method,a validating system has been built up and the experiments have been carried out. The results indicate that the proposed equivalent ground thermal test method can simulate the heat rejection performance of radiator correctly and the temperature error between in-orbit theory value and experiment result of the radiator is less than 0.5 C, except for the equipment startup period. This provides a potential method for the thermal test of space systems especially for extra-large spacecraft which employs single-phase fluid loop radiator as thermal control approach.     

基于PC/104的某飞机任务电源监控系统设计与实现

某飞机任务电源系统需要监控系统以保障飞行任务的供电安全.为提高其监控系统的可靠性和可维护性,完成了基于PC/104和远程数据采集模块的某飞机电源监控系统的设计与实现.该系统运用结合RS-485进行多串口通信,将采集的数据返回给监控界面,实现对远程终端的监控,以图形化编程软件LabVIEW为平台完成了采集与监控各部分的软件设计,并通过了各项测试,具有很好的稳定性和安全性,实现了对电源系统的监控、报警和保护.     

制样压应力对显微拉曼光谱法获取碳材料结构参数的影响

为了研究金相制样过程中压应力对获取碳材料拉曼特征参数R的影响,对不同温度处理的碳纤维和树脂碳进行了研究.结果表明,制样过程中的压应力对准确获取碳材料的拉曼特征参数具有一定的影响,尤其是对经过高温处理硬度较小的碳材料的影响更大,造成了碳材料R的增大.建议在制备碳材料的显微拉曼光谱测试试样时采用较小的压应力.     

UHMWPE/PCH复合材料性能研究

采用超高分子量聚乙烯(UHMWPE)纤维作增强材料,结构与UHMWPE纤维相似、且对纤维表面具有良好润湿性的全碳氢树脂(PCH)作基体,通过热压成型工艺制备UHMWPE/PCH复合材料,并通过扫描电镜、介电谱仪等方法对复合材料的力学性能、介电性能、吸水、湿热性能及界面粘接性能进行表征.结果表明,UHMwPE/PCH复合材料力学性能良好、介电性能优异、吸水率小、吸湿率低、粘接性能好.     

专访丹麦王国驻上海总领事馆总领事何丽兰女士

问:2010上海世博会是全球关注的一大盛事。阁下对明年的上海世博会有什么感言?答:我作为筹办方和世博会的组织成员,正好及时抵达上海,我很激动。我对我们的展馆和在馆内及周围举行活动制定的所有计划的进展有点担心。我们非常幸运地受到许多媒体的注意,支持设计师们将原型"小美人鱼"带到我们展馆的想法。这有助于保持我们团队高涨的情绪,并在中国和丹麦都得到了支持。问:2010上海世博会是全球关注的一大盛事,阁下对明年的上海世博会有什么感言?     

TC11钛合金的组织及塑性与其断裂韧性及裂纹扩展速率的关系

研究了TCll合金的组织及拉伸塑性(ψ)与断裂韧性(K_(IC)及裂纹扩展(da/dN)的关系。指明:K_(IC)及da/dN与ψ的关系取决于合金的组织类型。对片状组织及等轴组织进行了具体分析。     

转子分区循环对称接触应力分析

 通过光弹实验表明了端齿连接转子受力的分区循环对称性。针对这~特性建立了各循环对称分区的循环对称接触有限元应力分析方法,并利用叠加原理将各循环对称分区间过渡区化为几个小规模的循环对称问题。     

L8飞机从风洞到飞行的抖振相关性研究

介绍了Ｌ８飞机抖振边界修正结果，并与同类飞机Ｌ２９飞行抖振边界进行了比较；给出了Ｌ８飞机抖振边和轻度抖振边界预测值。同时将预测抖振边界和试飞得到的抖振边界作了比较。