装备参数漂移量与其可靠度的关系

本文从实际出发总结了参数漂移的统计规律,找到了参数漂移量X(t)与参数可靠度R(t)的统计关系,进而给出了利用X(t)的样本估计R(t的计算公式,用于实际简便易行。     

偏磷酸铝在Cf/AL 复合材料中的应用

以高模高强石墨纤维Ｍ４０Ｊ增强铝基复合材料为研究对象,研究了真空液相压渗工艺中,偏磷酸铝粘接剂对纤维预制件抗压性能及复合材料力学性能的影响。结果表明：偏磷酸铝的含量、Ａｌ／Ｐ原子比及处理温度对预制件的抗压性能均有显著影响,加入５％偏磷酸铝粘接剂溶液的预制件,经５００°Ｃ处理后的抗压性能满足压渗要求,纤维保持了较好的平直度及分布均匀性,所制备的复合材料抗拉强度大于５００ＭＰａ,抗弯强度大于８００ＭＰａ     

不同增强体镁基复合材料的阻尼性能

研究了短切碳纤维、碳化硅晶须、硼酸铝晶须为增强体的镁基复合材料在外加载荷下的阻尼性能,测量了它们的力学性能与断口特性。研究表明：增强体不同的镁基复合材料,阻尼性能不同;在所研究的几种增强体复合材料中,以短切碳纤维增强镁基复合材料的阻尼效果最好;短切碳纤维增强铁基复合材料界面对内耗有明显的影响。     

中口径舰炮对空闭环校射

首先建立了中口径舰炮武器系统对空闭环校射数学模型,比较新颖地解决了波门指示、弹序判别、滤波方法、脱靶量的求取和预测以及漏测弹丸的措施等一系列问题,通过仿真模拟明显地提高了系统精度和命中率,并使其工程化嵌入某型航炮系统,在工程上得以实现     

CLIENT／SERVER环境下的通用数据库开发工具POWERBUILDER

从面向对象的程序设计的角度,剖析了ＣＬＩＥＮＴ／ＳＥＲＶＥＲ环境下的通用数据库开发工具ＰＯＷＥＲＢＵＩＬＤＥＲ（ＰＢ）的特点、基本结构及其开发数据库应用系统的方法。     

Comparison of rank aggregation methods based on inherent ability

Ranking is a common task for selecting and evaluating alternatives. In the past few decades, combining rankings results from various sources into a consensus ranking has become an increasingly active research topic. In this study, we focus on the evaluation of rank aggregation methods. We first develop an experimental data generation method, which can provide ground truth ranking for alternatives based on their “inherent ability.” This experimental data generation method can generate the required individual synthetic rankings with adjustable accuracy and length. We propose characterizing the effectiveness of rank aggregation methods by calculating the Kendall tau distance between the aggregated ranking and the ground truth ranking. We then compare four classical rank aggregation methods and present some useful findings on the relative performances of the four methods. The results reveal that both the accuracy and length of individual rankings have a remarkable effect on the comparison results between rank aggregation methods. Our methods and results may be helpful to both researchers and decision‐makers.     

浅议我国农村社会保障改革

鉴于目前农村的社会阶层有了新的变化 ,必须加强农村社会保障工作的针对性 ,区别国内外不同国情 ,根据国内不同地区的情况采取因地制宜的政策 ,并在税收和慈善工作等方面做相应的调整     

弹炮混编防空群机动部署方案优选与评估

高技术条件下的反空袭作战中,弹炮混编防空群机动部署是相对传统防空作战中固定部署方式的一种新的部署方式,结合数学模型来确定机动部署的原则及部署方案的优化与评估。     

基于最优打击序列的弹道导弹火力分配模型研究

针对弹道导弹火力计划的拟制过程进行研究。围绕效费比最大化目标,对目标打击序列的影响因素进行了分析,设计了打击目标排序算法;采用层次分析法对弹道导弹打击能力进行了分析,并对打击目标所使用的作战单位排序值进行了计算,建立了最优火力分配模型。该模型不仅可最大发挥作战单位的作战能力,而且满足以最小代价获取最佳打击效果。     

Fracture mechanism of a cylindrical shell cut by circumferential detonation collision

The failure mechanism of a cylindrical shell cut into fragments by circumferential detonation collision was experimentally and numerically investigated. A self-designed detonation wave regulator was used to control the detonation and cut the shell. It was found that the self-designed regulator controlled the fragment shape. The macrostructure and micro-characteristics of fragments revealed that shear fracture was a prior mechanism, the shell fractured not only at the position of detonation collision, but the crack also penetrated the shell at the first contact position of the Chapmen-Jouguet (C-J) wave. The effects of groove number and outer layer thickness on the fracture behavior were tested by simulations. When the thickness of the outer layer was 5–18 mm, it has little effect on fragmentation of the shell, and shells all fractured at similar positions. The increase of the groove number reduced the fracture possibility of the first contact position of the C-J wave. When the groove number reached 7 with a 10 mm outer layer (1/4 model), the fracture only occurred at the position of detonation collision and the fragment width rebounded.