环面Fuchs方程解的性质及其可积性

研究环面Ｔ＾２上只有一个正则奇点的Ｆｕｃｈｓ方程，得到了参数ｒ＝６时，方程有一个椭圆函数解，其任何解皆为半纯函数，以及方程的单值群为可解群的结果。在此基础上，将Ｒｉｅｍａｎｎ球面上Ｆｕｃｈｓ方程的可积性概念推广到环面上，并得到一系列环面Ｆｕｃｈｓ方程都是可积的结果。     

飞机设计选材专家系统的开发

在对飞机设计选材工作进行分析的基础上,提出基于浏览器/服务器(B/S,Browser/Service)结构的飞机设计选材专家系统总体框架和系统各功能的实现方式,并开发了系统的原型.该系统将基于规则、案例和模型的选材方法结合在一起,通过一个通用的推理机实现推理.该推理机功能通过CLIPS(C Language Integrated Production System)专家系统开发工具实现.该系统主要有3个工作步骤:选材的定性推理,材料检索和材料综合性能排序.用户可以方便地使用浏览器对系统进行访问和操作.该系统飞机机翼大梁选材实例验证了该系统的有效性,可对飞机设计人员的选材工作起指导作用.     

TC18钛合金焊接接头力学性能试验研究

氩弧焊和电子束焊是钛合金加工中两类常见的工艺方法,对比研究两种工艺对焊接接头力学性能的影响对其在工程中的合理选用具有重要的参考价值。完成了TC18钛合金氩弧焊接头和电子束焊接头的静力拉伸及旋转弯曲疲劳试验,并根据试验结果对两类焊接接头的力学性能进行了对比分析,采用统计学方法给出了二者的中值疲劳寿命SN曲线及疲劳极限。研究结果表明：氩弧焊接头焊缝区内晶粒粗大,使得材料的力学性能明显劣化;电子柬焊接头具有更高的抗拉强度与更好的高周疲劳性能,更有利于工程应用。     

飞机空中跳伞应急出口切割装置设计与试验

爆破切割蒙皮形成应急出口在飞机上的应用国内尚属首次,其最大优点是节省救生准备时间.从爆炸减压、结构变形、结构强度、爆炸反向冲击等方面进行了理论计算,分析了高空爆破切割形成应急出口的可行性.针对切割索弯折过框及长桁降低切割效果问题,进行了摸底试验和余度试验,试验结果表明:只要过框位置切割索弯折后与框距离控制在2~8mm,过长桁位置切割索弯折后与长桁距离不大于2mm,就可以满足切割分离要求,切割索弯折后相互之间不产生影响.通过1∶1地面验证试验,证明了爆破切割蒙皮形成应急出口的可行性,并成功安装于某型飞机上.研究成果可为其他型号采用爆破切割技术提供理论基础和试验数据支持.     

The PROCESS experiment: amino and carboxylic acids under Mars-like surface UV radiation conditions in low-earth orbit

The search for organic molecules at the surface of Mars is a top priority of the next Mars exploration space missions: Mars Science Laboratory (NASA) and ExoMars (ESA). The detection of organic matter could provide information about the presence of a prebiotic chemistry or even biological activity on this planet. Therefore, a key step in interpretation of future data collected by these missions is to understand the preservation of organic matter in the martian environment. Several laboratory experiments have been devoted to quantifying and qualifying the evolution of organic molecules under simulated environmental conditions of Mars. However, these laboratory simulations are limited, and one major constraint is the reproduction of the UV spectrum that reaches the surface of Mars. As part of the PROCESS experiment of the European EXPOSE-E mission on board the International Space Station, a study was performed on the photodegradation of organics under filtered extraterrestrial solar electromagnetic radiation that mimics Mars-like surface UV radiation conditions. Glycine, serine, phthalic acid, phthalic acid in the presence of a mineral phase, and mellitic acid were exposed to these conditions for 1.5 years, and their evolution was determined by Fourier transform infrared spectroscopy after their retrieval. The results were compared with data from laboratory experiments. A 1.5-year exposure to Mars-like surface UV radiation conditions in space resulted in complete degradation of the organic compounds. Half-lives between 50 and 150?h for martian surface conditions were calculated from both laboratory and low-Earth orbit experiments. The results highlight that none of those organics are stable under low-Earth orbit solar UV radiation conditions.     

An innovative high accuracy autonomous navigation method for the Mars rovers

Autonomous navigation is an important function for a Mars rover to fulfill missions successfully. It is a critical technique to overcome the limitations of ground tracking and control traditionally used. This paper proposes an innovative method based on SINS (Strapdown Inertial Navigation System) with the aid of star sensors to accurately determine the rover?s position and attitude. This method consists of two parts: the initial alignment and navigation. The alignment consists of a coarse position and attitude initial alignment approach and fine initial alignment approach. The coarse one is used to determine approximate position and attitude for the rover. This is followed by fine alignment to tune the approximate solution to accurate one. Upon the completion of initial alignment, the system can be used to provide real-time navigation solutions for the rover. An autonomous navigation algorithm is proposed to estimate and compensate the accumulated errors of SINS in real time. High accuracy attitude information from star sensor is used to correct errors in SINS. Simulation results demonstrate that the proposed methods can achieve a high precision autonomous navigation for Mars rovers.     

轴向磁通磁场调制型电机的解析分析

提出了一种新型二维解析分析方法用于计算轴向磁通磁场调制型电机的气隙磁场分布和电机特性。对电机每个子域列出拉普拉斯方程或泊松方程并结合边界条件,求解出每个子域的矢量磁位,进而得到气隙磁场分布、空载反电势、电磁转矩和轴向磁拉力的解析表达式。为了评估解析方法的计算精度,对二维解析分析结果和三维有限元仿真结果进行了比较,结果表明二维解析计算结果的计算误差在10.3%以内。由于解析分析在保证计算精度的前提下大大缩短了计算时间,因此该方法适用于轴向磁通磁场调制型电机初始设计阶段电机参数的确定。     

光纤智能结构的传感网络敏感区域探测

实用的传感网络控制决策以及相应的控制系统保证了智能结构的使用可靠性,而传感网络敏感区域的确定影响到传感网络信号的有效性和传感网络覆盖位置的正确性.本文利用了与光纤智能结构匹配性较好的粗糙集理论粒度计算方法,对光纤智能结构的传感器网络敏感区域进行探测.在研究了机翼盒段光纤智能夹层传感网络后,得出了敏感区域分布和传感网络的覆盖位置,经过分析认为,此法可对光纤智能结构传感网络敏感区域进行探测并可以简省传感网络信号.     

LabVIEW——控制设计与仿真模块在转台设计中的应用

虚拟仪器技术在测试测量行业的广泛应用,推动了LabVIEW的发展.基于Lab-VIEW及其工具包在系统分析、设计中的优势,本文以控制设计与仿真模块为工具,设计单轴实验转台速度、位置控制器.完成了硬件选型、转台系统建模,在此基础上利用控制设计与仿真模块设计转台控制器.整个设计开发过程简单直观,并且经过仿真分析及实验验证,...     

基于FPGA的捷联惯组数据采集系统设计与实现

惯性器件性能的好坏直接决定了武器系统的性能,惯性器件的测试工作需要专门的脉冲采集系统来实现,本文介绍了一种基于FPGA的新型惯组脉冲采集系统,通过选用XC3S1000-4FGG676I芯片轻松实现了多路脉冲信号、交直流电压量以及温度传感器信号采集,抗干扰措施的采用有效地保证了该系统的稳定性和可靠性,经过大量的试验考核目前已经正式运用于捷联惯组的单元测试过程中。