Insensitive energetic microspheres DAAF/RDX fabricated by facile molecular self-assembly

Insensitive energetic materials are promising in the defense weapons field. However, energetic materials still suffer from great challenges and the concern about their safety limits their utilization. In this work, insensitive energetic explosive 3,3′-diamino-4,4′-azoxyfurazan/hexahydro-1,3,5-trinitro-1,3,5-triazine (DAAF/RDX) microspheres were fabricated by self-assembly method. Rod-like DAAF/RDX was prepared by mechanical ball milling for comparison. DAAF/RDX composites with different mass ratios (90:10, 80:20, and 70:30) were obtained. The morphologies and structures of as-obtained DAAF/RDX composites were characterized by scanning electron microscopy (SEM), powder x-ray diffraction (PXRD) and fourier transform infrared spectroscopy (FT-IR). The results showed that DAAF/RDX microspheres exhibited regular shaped microspheres with sizes from 0.5 to 1.2 μm. There was no crystal transition during the modification process. The thermal properties of as-obtained materials were then evaluated by differential scanning calorimetry (DSC) and materials studio software. DAAF/RDX microspheres showed an advanced decomposition peak temperature compared with rod-like DAAF/RDX. The binding energy and peak temperature values at zero β_i (T_P0) of DAAF/RDX (90:10) increased by 36.77 kJ/mol, 1.6 °C, and 58.11 kJ/mol, 12.3 °C compared to DAAF/RDX (80:20) and DAAF/RDX (70:30), indicating the better thermal stability of DAAF/RDX (90:10). The characteristic drop height (H₅₀) of DAAF/RDX (higher than 100 cm) composites was higher than that of raw RDX (25 cm), suggesting significant improvements in mechanical safety. The preparation of DAAF/RDX microspheres is promising for the desensitization of RDX and useful for the formation of other materials and future wide applications.     

A new appointment rule for a single-server,multiple-customer service system

This paper proposes a new appointment rule for the single-server, multiple-customer service system. Unlike previous appointment rules, which perform well only in specific service environments, the new rule can be parameterized to perform well in different service environments. The new appointment rule is presented as a mathematical function of four environmental parameters, namely, the coefficient of variation of the service time, the percentage of customers' no-shows, the number of appointments per service session, and the cost ratio between the server's idle and customers' waiting cost per unit time. Once the values of these environmental parameters are estimated, the new appointment rule can be parameterized to perform well. The results show that new rule performs either as well as or better than existing appointment rules in a wide range of service environments. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 313–326, 1998     

二维抛板极限速度的相似性与古尼公式的采用

本文分析影响被炸药驱动下抛板极限速度的重要因素,讨论了一些经验公式的适用范围;提出了根据二维抛板的数值计算得到的两个重要规律:①在炸药与抛板的质量比相同的情况下,抛板的极限速度之间具有一定的相似关系;②修正的古尼公式可用来计算二维抛板的极限速度。     

嵌入式计算机PC/104在陆地导航系统中的应用

随着现代导航技术的发展,嵌入式计算机技术已成为陆地导航系统中不可分割的重要组成部分。介绍了嵌入式工控机PC/104的结构特点及其应用开发特点;基于PC/104的系统设计思想,提出了以PC/104工控机为核心的陆地导航系统的设计方案,重点介绍了该系统的组成、各部件的作用、工作原理以及软件设计流程。这种嵌入式计算机软硬件相辅相成的有机构成,能集中统一地完成各部件的控制与信号处理,使整个陆地导航系统的性能与可靠性得到进一步提高。     

信念教育须把握的几个规律性问题

部队信念教育有可供把握的规律性问题。其中 ,对信念对象本质的认识和了解是信念形成的理论基础 ;对信念对象的体验是信念形成的实践基础 ;信念形成过程是信念主体按照信念对象的客观要求不断改造主观世界的过程 ;信念形成过程也是一个实践、认识、再实践、再认识的不断循环往复的过程     

更新美术教育思想 促进素质教育实施

美术教育是促进素质教育的一个很重要的方面。它对培养学生的创新意识和创造能力有着不可替代的作用。树立全新的美术教育思想 ,可促进素质教育深入开展     

基于区间数多指标决策的效能评估方法

针对武器效能评估的指标值以及度量指标权重的选取存在不确定性、模糊性和主观性的问题,根据作战效能的特点与系统工程思想,提出了基于区间数的灰色关联法和D-S证据理论相结合的效能评估方法。通过灰色关联法将指标区间值转化为以理想属性偏离度为测度的矩阵,在此基础上与D-S证据理论相结合,构造一种新的基本概率分配函数和新的信息不确定度提取方法,把不确定性问题转化为确定性问题,再利用D-S合成法则进行信息融合,确定最优方案。通过案例分析,结果表明该方法可以得到有效的决策结果并降低决策的不确定性。     

武器装备体系的经济可承受性成熟度评估

在武器装备体系方案论证初期,备选方案空间一般是非常巨大的,为了比较不同设计方案的国民经济承受能力和技术研制开发能力,介绍了基于能力的装备发展模式,定义了武器装备体系经济可承受性的概念,分析经济可承受性评估研究现状与存在不足,构建了武器装备体系的经济可承受性成熟度评价指标体系和数学模型,并进行了实例分析,结果表明,提出的评估模型可为体系的方案筛选、确定提供理论支持。     

马尔可夫随机场中应用蚁群系统的红外图像分割

利用蚁群系统(ACS)的信息正反馈和启发式的搜索特点,针对马尔可夫随机场(MRF)图像模型的局部相关特性和最大后验概率(MAP)估计,可以在较短时间内得到图像分割目标函数的全局最优解,从而可以避免传统模拟退火算法的庞大时间复杂度.通过对军用红外图像的分割实验,可以看出这种算法能够在抗噪声、保留目标边缘和降低时间复杂度方面得到较满意的结果.