声表面波对汽油胶质含量响应特性的理论与实验研究

从理论上分析了沉积于压电基片表面的汽油胶质对声表面波（SAW）传播特性的影响,在此基础上参照国家标准规定的汽油胶质含量测定试验条件,基于自制的SAW传感器,实验研究了SAW对不同汽油胶质含量的响应特性.结果表明SAW传感器的中心频率及幅度随SAW传播路径上沉积胶质的含量变化表现出敏感且单调的变化规律,这一结果可为车用汽油胶质含量的快速检测提供参考.     

电磁轨道发射中内弹道动力响应特性分析

将轨道简化为移动载荷作用下固定在弹性支撑上的Bernoulli-Euler梁,通过静态电磁-结构耦合有限元模型求得外围封装的等效刚度,计算得到发射器的临界速度。另外,利用混合有限元/边界元法建立电磁-结构-运动多物理场耦合的动力学模型,求得枢轨动态接触压力和轨道的应力应变分布特性。通过在轨道背面布置光纤光栅应变传感器,利用测量数据验证了动力响应特性,并分析了弹丸在内弹道的稳定性。针对典型30 mm × 30 mm矩形口径发射器,分析及试验结果表明：C型电枢对轨道的电磁挤压力在平顶沿起始时刻达到最大值,之后随着时间推移逐渐减小;电枢通过引起的应力波在高速段容易与轨道中反射应力波发生共振,并且轨道在电枢运动的中间高速段区域受力最为集中,应力集中水平约是起始低速段区域的2.44倍;电枢运动高速段会出现晃动现象,进而引起上下轨道受力的不对称性。分析及试验结果对研究电磁轨道发射器内弹道动力响应特性和发射器结构设计具有重要指导意义。     

现代花园洋房设计方法

花园洋房是具有悠久历史的住宅产品,现代花园洋房日益受到喜爱。为适应现代居住舒适、经济、安全的要求,寻求更加适合现代社会居住的花园洋房设计方法,基于花园洋房发展趋势与设计思想分析,结合具体设计方案,着重探讨套型叠加、空间过渡、下沉空间和洋房电梯等设计方法,从而为现代花园洋房设计方法的优化提供借鉴。     

Numerical investigation of the shockwave overpressure fields of multi-sources FAE explosions

Shockwaves from fuel-air explosive (FAE) cloud explosions may cause significant casualties. The ground overpressure field is usually used to evaluate the damage range of explosion shockwaves. In this paper, a finite element model of multi-sources FAE explosion is established to simulate the process of multiple shockwaves propagation and interaction. The model is verified with the experimental data of a fourfold-source FAE explosion, with the total fuel mass of 340 kg. Simulation results show that the overpressure fields of multi-sources FAE explosions are different from that of the single-source. In the case of multi-sources, the overpressure fields are influenced significantly by source scattering distance and source number. Subsequently, damage ranges of overpressure under three different levels are calculated. Within a suitable source scattering distance, the damage range of multi-sources situation is greater than that of the single-source, under the same amount of total fuel mass. This research provides a basis for personnel shockwave protection from multi-sources FAE explosion.     

Effects of total pressures and equivalence ratios on kerosene/air rotating detonation engines using a paralleling CE/SE method

In this paper, the kerosene/air rotating detonation engines(RDE) are numerically investigated, and the emphasis is laid on the effects of total pressures and equivalence ratios on the operation characteristics of RDE including the initiation, instabilities, and propulsive performance. A hybrid MPI + OpenMP parallel computing model is applied and it is proved to be able to obtain a more effective parallel performance on high performance computing(HPC) systems. A series of cases with the total pressure of 1 MPa, 1.5 MPa, 2 MPa, and the equivalence ratio of 0.9, 1, 1.4 are simulated. On one hand, the total pressure shows a significant impact on the instabilities of rotating detonation waves. The instability phenomenon is observed in cases with low total pressure (1 MPa) and weakened with the increase of the total pressure. The total pressure has a small impact on the detonation wave velocity and the specific impulse. On the other hand, the equivalence ratio shows a negligible influence on the instabilities, while it affects the ignition process and accounts for the detonation velocity deficit. It is more difficult to initiate rotating detonation waves directly in the lean fuel operation condition. Little difference was observed in the thrust with different equivalence ratios of 0.9, 1, and 1.4. The highest specific impulse was obtained in the lean fuel cases, which is around 2700 s. The findings could provide insights into the understanding of the operation characteristics of kerosene/air RDE.     

故障诊断效率与评估

叙述了电子设备故障诊断系统所进行检测的不同安排顺序对故障诊断效率的影响.提出了适当的检测顺序与检测方式,提高检查效率,缩短检查过程.还分析了每次进行故障诊断结果确诊或误诊随机现象,评判诊断准确率是抽样检验问题.引入假设检验方法,对设备故障诊断系统的准确率进行评判.对建造设备故障诊断系统有参考价值.     

项目管理模式下的装备研制合同管理的研究（续）

3．装备研制合同项目的管理流程 按照装备研制合同管理的管理流程,结合项目管理的特点,将装备研制合同项目划分为如下四个阶段：装备研制合同项目概念阶段（合同订立阶段）、装备研制合同项目开发阶段（合同履行计划阶段）、装备研制合同项目实施阶段（合同履行阶段）、装备研制合同项目收尾阶段（合同结束阶段）。     

计算机病毒辐射式注入技术实验研究

以ＤＯＳ系统无线网上的病毒注入及触发实验为依据,证明了辐射式病毒注入的条件及其可行性,并且分析了辐射式病毒注入的条件及其重要性,提出了一些攻击无线网计算机系统的病毒对抗的原则、前提、条件和方法。最后进一步说明了计算机病毒能够成为实用的作战武器。     

作战实体概念模型结构研究

本文将动态的作战实体视为智能实体,运用系统六元抽象方法对作战实体概念模型构成要素进行分析,明确了要素之间的相互关系,并从作战实体内部的状态、结构、行为出发,提出了一种以知识系统为中心的作战实体的概念模型结构。     

开山抚番:沈葆桢台湾防务建设中的重大举措

1874年日本侵台事件发生后,沈葆桢临危受命,赴台筹办台防。鉴于台湾生番地区的重要性,沈葆桢审时度势,着眼于台湾防务建设,施行了以“外防内治”为目的的开山抚番政策：开山修路、开禁招垦、增府置县、设立番学等,为促进台湾的政治、经济、文化全面发展,巩固台湾防务,发挥了积极作用。