One universal method of complex system reliability,maintainability, supportability,testability quotas design and trade-off based on improved flower pollination algorithm

For modern complex system, quality has become a serious and difficult problem that restricts the generation of combat effectiveness. Withal, based on domestic and foreign research and analysis, this paper puts forward a trade-off method for complex system reliability, maintainability, supportability, testability (RMST) design, which is suitable for product design stage. First, aiming at the uncertain problem of complex system constrained optimization, the good-point set population initialization, Deb feasibility comparison method and ε constraint method are integrated into the flower pollination algorithm, to construct the algorithm for RMST quotas design and trade-off. Second, taking the typical series-parallel repairable system as an example, one general model for complex system RMST quotas design and trade-off based on effectiveness is constructed. Finally, take an unmanned nuclear radiation detection system as a typical case, to verify its feasibility, advantages, and disadvantages.     

Enhanced electrode kinetics and electrochemical properties of low-cost NaFe2PO4(SO4)2 via Ca2+doping as cathode material for sodium-ion batteries

In recent years,sodium-ion batteries(SIBs)have been considered as one of the most promising alterna-tives to lithium-ion batteries(LIBs).Here,a new Na-super-ionic conductor(NASICON)cathode material NaFe2PO4(SO4)2 is successfully prepared through solid state method for SIBs.While the poor electronic conductivity of iron-based materials results in its poor rate and cycle performance.Then the electro-chemical is effectively promoting via Ca2+doping.Na0.84Ca0.08Fe2PO4(SO4)2 have achieved considerable electrochemical properties.The first discharge specific capacity is 121.6mAhg-1 at 25mAg-1 with the voltage platform(～3.1 V)corresponding to Fe2+/3+.After 100 cycles,the capacity retention is 55.1％.The excellent electrochemical performance is caused by some Na+is substituted by Ca2+and leading to the fast sodium kinetics,which is well proved by the powder X-ray diffraction pattern and well corresponding to the galvanostatic intermittent titration technique and cyclic voltammetry testing result(the diffusivity values are around at 10-12 cm2 s-1).     

Radio-frequency design of a new C-band variable power splitter

A novel variable C-band radio-frequency(RF)power splitter was designed at Shanghai Institute of Applied Physics, Chinese Academy of Sciences. Using three RF impedance combiners, an H-bend, and an RF polarizer, this new power splitter is much more compact than a traditionally designed splitter, which comprises three3-dB hybrids. The parameters were optimized to achieve good matching and minimize reflection. Here, the RF design of the new C-band variable power splitter is presented.     

基于冷量阈值的整流罩空调控制策略研究

针对某航天发射场整流罩空调机组经常出现前级蒸发器结霜和送风温湿度波动问题,进行问题机理分析,结合新风与表冷后目标露点的焓值差提出了一种基于冷量阈值的压缩机PID控制方法;该方法首先根据新风和目标露点的焓值差计算出处理空气所需的实际冷量,然后将该冷量作为基于露点PID控制压缩机输出的上限值;冷量阈值的使用一方面使PID控制一直保持欠调节状态,避免了压缩机投入比的上下跳变而导致送风温湿度波动的问题;另一方面有效解决了压缩机投入冷量过多而导致的蒸发器结霜问题;实践证明,优化后的空调机组运行稳定可靠,温湿度控制精度得到有效提升,分别达到了±0.5 ℃和±3%,满足航天器产品保障需求。     

新型圆弧角回转断屑器设计与切屑折断实用预报公式的建立

依据断屑原理,研究和设计一种新型圆弧角回转断屑器。该断屑器在整体上呈圆台状,在锥面上均匀设置了圆弧角。结合压板,断屑器实现断屑可靠、断屑范围宽、操作简便、使用寿命长等功效。同时推导出在该装置下的切屑过销钉的回转轴线与切屑流速方向所形成的剖面内的折断和切屑沿回转断屑器回转折断两种极限情况的切屑折断实用预报公式;进行了两种极限情况的断屑试验,试验研究结果验证了该断屑器的有效性。     

基于特征的参数化造型技术族研究与应用

对参数化设计技术、特征技术和基于参数化的特征造型技术做了系统地回顾,在深入地剖析上述技术的基础上,提出了综合运用各技术优点的基于特征的参数化造型技术族的概念及原理。最后给出了以Pro／E为平台,运用基于特征的参数化造型技术族原理于渐开线斜齿圆柱齿轮的实例。     

经济波动时期的城市与区域规划思考

通过回顾美国经济发展的历史过程可知,2008年下半年以美国为核心引发的全球经济危机是一次生产过剩的危机,具有劳动力剩余、生产力剩余、资本剩余同时存在的特征.面对这种危机,我国可以通过推进城市化进程达到化解危机风险的目标.规划师应关注生产过程技术、流通技术、流通技术对城市与区域的影响,加深对"巨型城市区"这个新的城市与区域空间形态的了解,以创造性地规划适应全球经济危机后的新城市一生产系统框架,开创城市与区域规划的新思路、新理论和新方法.     

一种基于P圈的ASON混合故障保护模型

在研究自动交换光网络(ASON)中发生节点/链路混合故障时的保护方法的基础上,设计了一种同时考虑节点故障和链路故障情况的基于P圈的保护模型,同时给出了一种保证在混合故障时可以达到100%业务恢复率的预配置P圈保护的启发式算法,并且综合考虑了实际网络中保护恢复速度和资源效率等因素,给出了具有最大P圈跳数限制的P圈配置方案.利用OPNET软件搭建了ASON仿真平台,在泛欧Cost239网络拓扑和北美NSFnet网络拓扑上,采用静态业务模型对该算法进行了仿真分析.仿真结果证明,该算法在拥有故障业务快速恢复能力的同时,相比已有算法具有更低的资源冗余度.     

基于旋转SURF算子的图像配准新方法

针对SURF算法中快速Hessian矩阵行列式检测出的特征点的不连续现象,从而造成的旋转,模糊和光照变化适应性较差的不足,提出一种旋转SURF检测算子的图像配准新方法;该算法通过将SURF算法的积分图像盒子滤波模板逆时针旋转45度,引入一种可以检测角度旋转的滤波核提升检测算子对不同图像变换的匹配性能,保证新的检测算子与原算法较好的结合,同时利用改进的单纯形算法依据输入图像进行参数优化;仿真结果表明,该方法不仅保留了算法的速度优势,缩短了配准时间,而且在图像模糊变换,光照变换和JPEG压缩变换方面性能有明显的提升,此外对视角变换以及小尺度变换性能也有提高。