Preparation and characterization of HMX/EVA/hBNNSs micro-composites with improved thermal stability and reduced sensitivity

Hexagonal boron nitride nanosheets(HBNNSs)have huge potential in the field of coating materials owing to their remarkable chemical stability,mechanical strength and thermal conductivity.Thin-layer hBNNSs were obtained by a liquid-phase exfoliation of h-BN powders and incorporated into EVA coatings for improving the safety performance of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX).HBNNSs and ethylene-vinyl acetate copolymer(EVA)were introduced to HMX by a solvent-slurry process.For com-parison,the HMX/EVA and HMX/EVA/graphene(HMX/EVA/G)composites were also prepared by a similar process.The morphology,crystal form,surface element distribution,thermal decomposition property and impact sensitivity of HMX/EVA/hBNNSs composites were contrastively investigated.Results showed that as prepared HMX/EVA/hBNNSs composites were well coated with hBNNSs and EVA,and exhibited better thermal stability and lower impact sensitivity than that of HMX/EVA and HMX/EVA/G composites,suggesting superior performance of desensitization of hBNNSs in explosives.     

作战构想风险性评估模型

作战构想是制定作战方案、定下作战决心的依据,在任务规划中起着承上启下的作用,意义重大.针对构想风险难以定量分析的难题,基于作战构想的组成要素、战场情况分析研判数据,从周密性、机动、打击、防护等角度构建了作战构想风险性评估指标体系,并提出了对各个指标进行定量分析的评估模型.最后,采用实例对提出的方法进行了验证,结果表明,...     

Revenue management under randomly evolving economic conditions

We consider a dynamic pricing model in which the instantaneous rate of the demand arrival process is dependent on not only the current price charged by the concerned firm, but also the present state of the world. While reflecting the current economic condition, the state evolves in a Markovian fashion. This model represents the real‐life situation in which the sales season is relatively long compared to the fast pace at which the outside environment changes. We establish the value of being better informed on the state of the world. When reasonable monotonicity conditions are met, we show that better present economic conditions will lead to higher prices. Our computational study is partially calibrated with real data. It demonstrates that the benefit of heeding varying economic conditions is on par with the value of embracing randomness in the demand process. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 66:73–89,2019     

Mathematical formulation and heuristic algorithm for the block relocation and loading problem

This study considers the block relocation and loading problem in container terminals. The optimal loading sequence and relocation location are simultaneously decided on the basis of the desired ship‐bay and initial yard space configuration. An integer linear programming model is developed to minimize the number of relocations in the yard space on the basis of no shifts in the ship bay. The accuracy of the model is tested on small‐scale scenarios by using CPLEX. Considering the problem size in the real world, we present a rule‐based heuristic method that is combined with a mathematical model for the removal, loading, and relocation operations. The influence of rules on algorithm performance is also analyzed, and the heuristic algorithm is compared with different types of algorithms in the literature. The extensive numerical experiments show the efficiency of the proposed heuristic algorithm.     

基于Focal Loss的多特征融合地物小目标检测

针对无人机影像中地物车辆目标占整体像素不超过0.4％的小目标检测效果差的问题,在融合FPN结构的Faster R-CNN(FFRCNN)网络基础上,提出一种改进算法——FM-FFRCNN.利用Resnet-50网络进行特征提取,并联多个卷积核进行卷积操作实现多特征融合,达到扩大感受野的效果,并通过检测模块进行回归与分类...     

基于禁忌搜索的作战重心分析与选择方法

研究了作战目标网络的重心分析与选择方法,为战场指挥员的指挥决策提供依据.定义了战场重心的概念,从考虑打击代价的角度建立重心发现的优化模型,给出了基于禁忌搜索的求解算法,并通过实验案例验证了模型和算法的有效性和可行性.     

分布式导弹发射控制系统设计模型

分布式导弹发射控制系统是以多微机结构处理导弹发射控制过程的一种控制系统,是当代导弹武器发射控制系统所广泛采用的一种先进技术。通过对某类常规战术导弹实施分布式发射控制模型设计的分析,探讨了分布式微机结构在军事控制领域的应用前景     

基于雷达网拓扑特征的雷达目标编群算法

为有效评估战场电磁态势和实施雷达网对抗,研究雷达目标编群算法十分必要。提出了一种基于拓扑特征分析的雷达目标编群算法,在分析雷达网拓扑结构及其特征基础上,利用拓扑特征实现雷达目标群的建立和更新,完成雷达目标编群。仿真实例表明算法具有可行性和有效性,为电磁态势评估和雷达网对抗奠定了基础。     

新疆少数民族汉语语法教学实践探索

文章依托认知教学理论和建构主义学习观,通过解读《全日制民族中小学汉语课程标准》提出的新要求,对包括直观、演绎、归纳、对比、图表、游戏、交际、任务等多种教学方法进行了阐述。文章认为对少数民族汉语语法教学要注重实践语法的特点,学生的年龄特点、心理认知水平,对语法偏误进行分析,同时应注重教学语法内容的逻辑性,通过灵活运用多种教学方法,促进学习者语法知识的建构,提高语法学习的效率。