Numerical study on the case effect of a bomb air explosion

When considering the bomb explosion damage effect, the air shock wave and high-speed fragments of the bomb case are two major threats. In experiments, the air shock wave was studied by the bare ex-plosives superseding the real cased bomb; in contrast, the bomb case influence was ignored to reduce risk. The air explosion simulations of the MK84 warhead with and without the case were conducted. The numerical simulation results showed that the bomb case significantly influenced the shock wave generated by the bomb: the spatial distribution of shock wave in the near field changed, and the peak value of shock wave was reduced. Breakage of the case and kinetic energy of the fragmentation consumed 3 and 38% of the explosion energy, respectively. The increasing factors of the peak over-pressure induced by the bare explosive on the ground and in the air were 1.43-3.04 and 1.37-1.57, respectively. Four typical stages of case breakage were defined. The mass distribution of the fragments follows the Mott distribution. The initial velocity distribution of the fragments agreed well with the Gurney equation.     

超宽带雷达回波的双谱分析方法

谱分析是雷达信号处理的重要组成部分,对目标分类、特征检测均有重要意义。高阶谱所具有的特殊性质,有助于人们从新的角度对雷达回波进行分析。本文提出了一种双谱分析双（Ｑ,Ｋ）方法。仿真结果表明,本文提出的方法与其它的双谱估计算法相比估计精度更高。最后给出了应用实例     

防空中存在两次转火射击时的火力分配模型

在对空防御时 ,进行火力分配不但要考虑到一次性分配的最佳方案 ,而且应该考虑是否在条件允许的情况下进行一次或两次转火射击 ,如果存在 ,怎样进行转火才能使其射击效果最好。把威胁判断和火力分配结合起来考虑 ,以我方的生存概率为指标 ,建立了存在两次转火射击的火力分配模型 ,并用实例计算检验了模型的正确性。     

积极推进部队思想政治教育载体创新

面对信息技术迅猛发展的新形势,必须积极推进部队思想政治教育的载体创新,增添思想政治教育的时代元素,拓展思想政治教育的实践平台,强化思想政治教育的育人功能,构建思想政治教育的崭新格局。     

Optimizing natural gas pipeline transmission with nonuniform elevation: A new initialization approach

In this paper, we develop an iterative piecewise linear approximation approach with a novel initialization method to solve natural gas pipeline transmission problems with the nonuniform network elevation. Previous approaches, such as energy minimization methods, cannot be applied to solve problems with the nonuniform network elevation because they exclude pressure range constraints, and thus provide solutions far from optimum. We propose a new initialization model that considers pressure range constraints and improves the optimality of the solutions and the computational efficiency. Furthermore, we extend the energy minimization methods and provide the necessary conditions under which the extended methods operate in networks with the nonuniform elevation. We test the performances of the methods with previously reported pipeline networks from the literature, with the open data set GasLib, and with our industrial collaborator. The initialization approach is shown to be more efficient than the method with fixed initial breakpoints. The newly proposed initialization approach generates solutions with a higher accuracy than the extended energy minimization methods, especially in large‐size networks. The proposed method has been applied to natural gas transmission planning by the China National Petroleum Corporation and has brought a direct profit increase of 330 million U.S. dollars in 2015‐2017.     

马汉海权论的形成及其影响

19世纪末,美国海军上校马汉提出了系统的海权论观点,主要内容是:海洋对濒海国家的生存与发展有决定性的意义,而要拥有海权就必须发展强大的海军并在海外取得补给基地.这一理论不仅准确地反映了当时欧关列强争夺海外殖民地的趋势,更为这种争夺提供了理论依据,故一旦出现立即风靡全球,对世界各国产生了广泛而深远的影响.     

浅论工程装备试生产过程中的工艺评审及工艺鉴定

本文通过分析现行相关标准中工艺评审和工艺鉴定的内涵,说明了工程装备首批产品试生产过程中实施工艺评审做法的不合理之处,探讨了实施工艺鉴定的可行性以及要求、内容和方法,对完善工程装备首批产品质量评审工作,保证后续批量生产质量具有借鉴意义,以期共同探讨。     

三维视觉运动建模中碰撞检测算法研究

三维视觉建模是建立虚似现实 (VR)系统的基础 ,运动建模是三维视觉建模的重要组成部分。研究了运动建模中碰撞检测算法     

虚拟现实系统的建模方法

采用先进的建模方法 ,开发组织和管理复杂的虚拟环境 ,不仅能够提高开发效率 ,甚至关系到项目开发的成败。研究了面向对象和面向智能体两种虚拟现实 (VR)系统设计的基本方法。