单线长距离通讯技术及抗干扰设计

提出了单片机串行RS-485单线通讯的技术实现方案、串行通讯的软件设计及设计过程中的抗干扰措施。     

涡轮机械转子/密封稳定性研究综述

介绍了流体密封对转子稳定性的影响。阐述了基于体积流模型和流场计算的稳定性分析方法，及利用密封结构设计对转子动态特性进行主动控制的方法，指出了转子／密封稳定性研究的发展趋势：一是发展适应性强的流体流动和转子动力特性分析的数值计算技术，在转子设计阶段进行流体诱导稳定性分析；二是利用密封刚度阻尼特性。改善转子动态特性。     

CORBA规范及其技术核心

CORBA(通用对象请求代理结构)规范被称为是面向21世纪的软件总线.已成为流行的分布对象计算规范.CORBA规范的内容很丰富,本文着重从整体上把握CORBA的体系结构和核心内容.基于对CORBA的发展和技术特色的介绍,本文详细讨论了OMA(对象管理体系结构)模型、ORB系统组成和ORB运行过程.     

环境应力筛选是提高航空产品可靠性的保证

通过对外场故障数据和实验室故障数据的分析,说明元器件缺陷和制造缺陷所造成的各种故障是产品现场使用可靠性下降的主要因素,提出大力推行环境应力筛选是提高产品现场使用可靠性的有效办法。     

集中交联硅橡胶硫化体系及其工艺

采用动态热机械分析仪RSA3代替硫化仪来测试硅橡胶的硫化特性,使用多乙烯基硅油(C胶)作为集中交联剂,分别选择DCP、BPO及两者并用硫化体系作为集中交联硅橡胶体系的硫化剂,研究了不同硫化剂对集中交联硅橡胶硫化曲线的影响,分析了硅橡胶在不同硫化体系下发生交联反应的差异,讨论了硅橡胶在不同温度下的硫化反应速率.研究结果表明:对于集中交联体系的硅橡胶,BPO硫化效果不好,DCP能有效硫化,并用硫化体系的硫化效果最好,且可以在不影响其硫化反应速率的同时使硅橡胶实现高低温分段硫化.     

Investigation of lateral-directional aerodynamic parameters identification method for fly-by-wire passenger airliners

A new identification method is proposed to solve the problem of the influence on the loaded excitation signals brought by high feedback gain augmentation in lateral-directional aerodynamic parameters identification of fly-by-wire（FBW） passenger airliners. Taking for example an FBW passenger airliner model with directional relaxed-static-stability, through analysis of its signal energy distribution and airframe frequency response, a new method is proposed for signal type selection, signal parameters design, and the appropriate frequency relationship between the aileron and rudder excitation signals. A simulation validation is presented of the FBW passenger airliner＇s lateral-directional aerodynamic parameters identification. The validation result demonstrates that the designed signal can excite the lateral-directional motion mode of the FBW passenger airliner adequately and persistently. Meanwhile, the relative errors of aerodynamic parameters are less than 5%.     

模拟月壤对蓝细菌生长特性的影响

阐明地球生物在月球环境中的适应性是未来月球探索和基地构建所面临的重要课题,为此以蓝细菌为实验材料,对其在模拟月壤cas-1中的生长状态进行了研究,从生长速率、细胞形态、细胞色素含量等方面表征了月壤对蓝细菌适应性的影响。实验结果表明,四种实验蓝细菌的生长能够适应模拟月壤的影响,其生长速率在模拟月壤处理中保持与常规培养基相似的生长曲线;模拟月壤颗粒上附着生长的菌体形态与对照相比无明显变化;模拟月壤处理后的菌体内色素含量与对照条件下培养的结果无显著差异。该结果对于未来开发月壤资源和构建月球基地受控生态生保系统具有重要意义。     

Effect of salt stress on growth and physiology in amaranth and lettuce: Implications for bioregenerative life support system

Growing plants can be used to clean waste water in bioregenerative life support system (BLSS). However, NaCl contained in the human urine always restricts plant growth and further reduces the degree of mass cycle closure of the system (i.e. salt stress). This work determined the effect of NaCl stress on physiological characteristics of plants for the life support system. Amaranth (Amaranthus tricolor L. var. Huahong) and leaf lettuce (Lactuca sativa L. var. Luoma) were cultivated at nutrient solutions with different NaCl contents (0, 1000, 5000 and 10,000 ppm, respectively) for 10 to 18 days after planted in the Controlled Ecological Life Support System Experimental Facility in China. Results showed that the two plants have different responses to the salt stress. The amaranth showed higher salt-tolerance with NaCl stress. If NaCl content in the solution is below 5000 ppm, the salt stress effect is insignificant on above-ground biomass output, leaf photosynthesis rate, Fv/Fm, photosynthesis pigment contents, activities of antioxidant enzymes, and inducing lipid peroxidation. On the other hand, the lettuce is sensitive to NaCl which significantly decreases those indices of growth and physiology. Notably, the lettuce remains high productivity of edible biomass in low NaCl stress, although its salt-tolerant limitation is lower than amaranth. Therefore, we recommended that amaranth could be cultivated under a higher NaCl stress condition (<5000 ppm) for NaCl recycle while lettuce should be under a lower NaCl stress (<1000 ppm) for water cleaning in future BLSS.     

空间探索用梯度密度气凝胶的合成与应用进展

气凝胶是空间探索领域的关键功能材料.系统介绍了单一密度气凝胶和梯度密度气凝胶材料的分类、合成方法、复合工艺、特殊性能及其在空间探索领域的应用.其中,梯度密度气凝胶材料的合成是国际上的技术难点,笔者结合自身研究将其复合方式分为早期方法、分层粘贴法、逐层凝胶法和梯度溶胶共凝胶法,揭示了梯度气凝胶应遵循由单位深度的低差异到高...     

极大似然法在飞机极曲线辨识中的应用

介绍了利用极大似然法辨识飞机极曲线的基本原理。通过仿真研究及对实测飞行试验数据的处理，表明该方法能够辨识出光滑的非线性飞机极曲线，算法具有良好的收敛性及结果的唯一性，并且可方便地推广应用于工程中其它类型的非线性曲线辨识问题。