H2O2/HTPB固液混合发动机点火试验研究

利用H2O2催化分解原理,设计了烃类燃料在催化分解的90%H2O2中能燃烧的点火器,然后采用该点火器进行H2O2/HTPB固液混合发动机点火试验研究.试验结果表明,该点火器能够成功启动H2O2/HTPB固液混合发动机,且当混合比偏离最佳混合比后,发动机的燃烧效率降低.     

Estimating failure time distribution and its parameters based on intermediate data from a Wiener degradation model

Instead of measuring a Wiener degradation or performance process at predetermined time points to track degradation or performance of a product for estimating its lifetime, we propose to obtain the first‐passage times of the process over certain nonfailure thresholds. Based on only these intermediate data, we obtain the uniformly minimum variance unbiased estimator and uniformly most accurate confidence interval for the mean lifetime. For estimating the lifetime distribution function, we propose a modified maximum likelihood estimator and a new estimator and prove that, by increasing the sample size of the intermediate data, these estimators and the above‐mentioned estimator of the mean lifetime can achieve the same levels of accuracy as the estimators assuming one has failure times. Thus, our method of using only intermediate data is useful for highly reliable products when their failure times are difficult to obtain. Furthermore, we show that the proposed new estimator of the lifetime distribution function is more accurate than the standard and modified maximum likelihood estimators. We also obtain approximate confidence intervals for the lifetime distribution function and its percentiles. Finally, we use light‐emitting diodes as an example to illustrate our method and demonstrate how to validate the Wiener assumption during the testing. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

关于Chidume结果的推广

在一致光滑的Banach空间,证明了满足不等式‖Tx≤C ‖x‖的一类非线性强增生算子的Mann迭代序列强收敛于Tx=f的唯一解。     

AHP法在舰空导弹作战通道分析中的应用

层次分析法(AHP)是一种简便、灵活而又实用的多准则决策的系统分析方法。运用该分析方法对舰空导弹武器各作战通道的性能进行综合分析,其中在对决策矩阵进行计算时,使用了三种不同的效用函数对方案层的各项指标进行了量化,最后得出了各作战通道的综合价值,此值可为指挥员决策提供参考。计算结果表明该方法用于作战通道评价是切实可行的。     

孔子因材施教思想对体育课堂教学的启示

孔子因材施教的教育思想不仅对我国古代教育的发展产生了深远的影响 ,对今天体育课堂教学也具有重要的启示意义 ,因材施教是体育课堂教学的根本措施和质量保证     

BTT控制系统半实物仿真方案 设计及试验结果分析

BTT控制系统半实物仿真试验以BTT试验器为背景,配合BTT控制技术研究可全面验证导弹控制系统设计。给出了半实物仿真试验方案、方法及试验结果分析,试验结果表明BTT控制系统设计满足最小侧滑(近似零侧滑角)倾斜转弯的技术指标要求,半实物仿真试验方法正确。     

多级可修备件库存的生灭过程建模与优化

针对VARI-METRIC模型在低可用度下结果不准确的问题,建立基于生灭过程的任意等级、任意层级可修件库存优化模型。通过对各级站点、各类备件需求率与到达率的预测,对每个部件建立其生灭过程模型,并提出基于生灭过程的装备可用度计算方法。以整个保障系统的装备可用度为约束指标,以备件总购置费最低为目标,利用边际算法得到最优备件配置方案,并建立仿真模型对所得优化方案进行评估与调整。结合算例,以仿真结果作为检验标准,选取权威的VMETRIC软件与该解析模型在优化性能、计算精度及适用性上进行对比和说明。结果表明,无论是解析模型还是VMETRIC软件,均存在一定的适用范围,而采用解析与仿真相结合的方法无疑具有更强的适应性。     

Computational analysis of MMAP[K]/PH[K]/1 queues with a mixed FCFS and LCFS service discipline

This paper studies a queueing system with a Markov arrival process with marked arrivals and PH‐distribution service times for each type of customer. Customers (regardless of their types) are served on a mixed first‐come‐first‐served (FCFS) and last‐come‐first‐served (LCFS) nonpreemptive basis. That is, when the queue length is N (a positive integer) or less, customers are served on an FCFS basis; otherwise, customers are served on an LCFS basis. The focus is on the stationary distribution of queue strings, busy periods, and waiting times of individual types of customers. A computational approach is developed for computing the stationary distribution of queue strings, the mean of busy period, and the means and variances of waiting times. The relationship between these performance measures and the threshold number N is analyzed in depth numerically. It is found that the variance of the virtual (actual) waiting time of an arbitrary customer can be reduced by increasing N. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 399–421, 2000     

论法治进程中的正当程序

法治的实现有赖于法治要素的具备,而正当程序有助于法治要素的满足。法治社会应具有的正当程序理念是:正当程序是对人权的尊重和保护,是实现正义的重要途径,程序正义优先于实体正义。     

普通物理实验教学体系和考核方法的改革

文章对我校近几年来形成的普通物理实验课教学和考核体系做了一个总结。并对未来大学物理实验教学提出了合理设想和期望。