2A12-T4铝合金零件去应力处理工艺研究

针对2A12-T4铝合金薄板类零件在加工过程中,采用110℃保温6小时去应力处理后,对材料硬度略有升高的现象进行了不同参数的工艺试验,试验结果表明在240℃～260℃范围内加热4～6小时的去应力处理,既可降低材料硬度HRB4～7,又能满足设计要求的强度指标,对降低零件机械加工切削力、减小零件残余应力是十分有利的。     

基于EEC检测系统的t4通道检测研究

飞机性能的提高,对发动机推进控制系统提出了更高的要求。基于EEC检测系统,对t4通道进行了独立检测试验,得出了通道在4种工作状态下t4与S1的特性关系。结合通道原理电路,对试验结果进行了分析。辨识结果证明通道为变结构控制系统。试验证明,EEC检测系统设计合理,安全可靠,抗干扰,具有较高的精确度,对研究EEC内部控制规律具有重要意义。     

欠采样信号多采样频率处理方法

讨论了带通信号 A/D 转换中的欠采样问题,通过引入余数定理,给出了一种使用多采样频率的欠采样解决方案。以模数转换为例阐述欠采样问题的解决思路,给出了一些结论。     

激光选区熔化成形TC4钛合金的电子束焊接气孔缺陷控制研究

激光选区熔化(SLM)增材制造技术常用于格栅、腔体结构、燃烧室组件等航空、航天、兵器领域复杂小型零件的制造.为了适应大尺寸零部件的制造,较为理想的方案是采用分段增材成形+拼焊连接的方案,针对SLM成形TC4钛合金进行了电子束焊接工艺验证研究,分析了SLM成形材料焊接气孔缺陷及其产生原因,探讨了不同焊接工艺对气孔缺陷的改...     

我国航天测控通信系统配置CCSDS SLE业务方案设计

介绍了CCSDS SL正业务的具体内容,提出了在我国航天测控系统中采用CCSDS标准的SLE传输协议实现国际联网的设想,并给出了前向遥控SLE业务的配置方案。     

高性能M40J/BADCy复合材料的研究

对E51环氧树脂改性双酚A型氰酸酯(BADCy)体系的力学性能及热性能进行了研究,发现当E51环氧树脂的质量含量为5%时,改性体系的弯曲强度和冲击强度分别由原来的95.6MPa和9.24kJ/m²提高到了117.8MPa和12.6kJ/m²,而热变形温度仅下降8℃。以该改性体系为基体制作的M40J复合材料,其弯曲强度、模量和剪切强度分别高达:1270MPa,172GPa,68 9MPa。消泡剂BYK141能提高M40J/BADCy复合材料的力学性能,层间剪切强度可提高到77.1MPa。M40J/BADCy复合材料还具有良好的耐环境能力,是一种理想的航空航天结构材料。     

Space Flight Validation of Design and Engineering of the ZDPS-1A Pico-satellite

The ZDPS-1A pico-satellites are the first satellites in China within the 1-10 kg mass range that are successfully operated on orbit. Unlike common pico-satellites, they are designed to be "larger but stronger" with more powerful platforms and unique payloads so as to bear a better promise for real applications. Through their space flight mission, the functionality and performance of the two flight models are tested on orbit and validated to be mostly normal and in consistency with design and ground tests with only several inconforming occasions. Moreover, they have worked properly on orbit for one year so far, well exceeding their life expectancy of three months. Therefore, the space flight mission has reached all its goals, and verified that the design concept and the engineering process of the picosatellites are sufficient in allowing them the desired functionality and performance in, and the adaption to the launch procedure and the low-Earth orbit space environment. In the foreseeable future, the platform together with the design concept and the engineering process of the pico-satellites are expected to be applied to more complicated real space applications.     

粉末冶金Ti-6Al-4V 的组织及形成机理

利用热等静压(HIP)技术及旋转电极粉,采用预合金粉工艺制备了全致密的粉末冶金Ti-6Al-4V合金,用光学显微镜对其金相组织进行了观察,分析其形成机理,并对粉末冶金Ti-6Al-4V合金的室温拉伸性能、弹性模量、冲击性能及断裂韧性进行了研究.结果表明:粉末冶金Ti-6Al-4V金相组织主要由条片α相+相间β相组成,有细小的等轴α相分布在晶粒界面处,包裹着条片α相,这种独特的组织状态是由制备工艺决定的,具有良好的综合性能.     

Involvement of nitric oxide in the mechanism of biochemical alterations induced by simulated microgravity in Microcystis aeruginosa

Simulated microgravity (SMG) can inhibit proliferation and enhance microcystin production of Microcystis aeruginosa. We investigated the role of nitric oxide (NO) in regulating the SMG induced changes of proliferation, photochemical system II photochemical activity, pigment, soluble protein and microcystin production in M. aeruginosa. M. aeruginosa was exposed to 0.1 mM sodium nitroprusside (SNP, NO donor) or 0.02 mM 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO, NO scavenger) alone or in combination with SMG for 48 h. SMG and SNP inhibited the growth of M. aeruginosa while c-PTIO had no effect on cell number. As to yield, the negative effect of SMG was augmented by SNP and suppressed by c-PTIO. The intracellular concentrations of chlorophyll a, carotenoid, phycocyanin, soluble protein and microcystin were increased by SMG after 48 h. The effects of SMG on these metabolic processes could be enhanced by SNP and be partly eliminated by c-PTIO. Moreover, SNP and c-PTIO only functioned in these biochemical processes under SMG, unlike in the regulation of cell proliferation and yield. These results showed that the effects of SMG could be enhanced by adding exogenous NO and be mitigated by scavenging endogenous NO, revealing the involvement of NO in the changes in biochemistry processes induced by SMG in M. aeruginosa.     

“嫦娥4号”自主运行任务的设计与实现

从自主运行需求获取、自主运行策略设计、自主运行任务实现3个方面对"嫦娥4号"自主运行任务进行研究。通过在轨飞行验证,"嫦娥4号"自主运行任务的实现除了完善自我诊断及重构能力,还增强了对未知风险的应对能力,增加核心设备的自主管理能力,保证关键事件完成的可靠性与精准性。不仅总结了重要的工程经验而且为未来深空自主运行任务的设计实现提供了直接而有力的技术支持。