引信电子部件ESD效应和加固实验研究

利用静电放电模拟器对某电子时间引信的电子部件的损伤及其防护加固进行了实验研究。引信部件在ESD的作用下,储存的信息会改变;当ESD的电压进一步升高时,引信中的电子部件出现损坏,其损伤阈值为＋200V．采取加固措施后,系统抗ESD的电压提高了2～3倍,达到了预期的目的。     

The impact of exponential smoothing forecasts on the bullwhip effect

An important phenomenon often observed in supply chain management, known as the bullwhip effect, implies that demand variability increases as one moves up the supply chain, i.e., as one moves away from customer demand. In this paper we quantify this effect for simple, two‐stage, supply chains consisting of a single retailer and a single manufacturer. We demonstrate that the use of an exponential smoothing forecast by the retailer can cause the bullwhip effect and contrast these results with the increase in variability due to the use of a moving average forecast. We consider two types of demand processes, a correlated demand process and a demand process with a linear trend. We then discuss several important managerial insights that can be drawn from this research. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 269–286, 2000     

[AXB,GXH]=[C,D]对称最小二乘解及最佳逼近的极小残差法

构造迭代算法研究了矩阵方程[AXB,GXH] = [C,D] ,证明了该算法可经有限步得到方程的对称最小二乘解及其最佳逼近,并给出了相关性质.最后,通过数值例子表明该算法是有效的.     

基于人工神经网络的操作手IKP 求解

人工神经网络以其信息的并行处理与分布式存储、自组织和自适应等特点,在机器人领域显示了极大的应用潜力。本文探讨人工神经网络在机器人操作手ＩＫＰ求解中的应用,试图求得操作手ＩＫＰ的一组或所有可行解。文章利用ＢＰ网络对操作手ＩＫＰ的求解进行了讨论和分析,并给出了具体的求解实例。     

美军建模与仿真管理特点及启示

美军是世界上唯一建立战争全域模拟仿真体系的军队,其建模与仿真建设高效管理的一些经验值得我军借鉴。本文归纳了美军建模与仿真管理5个方面的特点：高层机构统一领导,专职部门实施管理,以促进协作和共享为重点,规范化管理,模型、数据与服务一体化管理。并针对我军建模与仿真应用领域不广、协作共享不够、数据与服务管理欠缺的问题,提出了相应的建议。     

潜艇通信侦测与防御探讨

从通信对抗角度出发,简述了实现通信侦测的样式,重点论述了通信防御的主要技术手段。并结合潜艇兵力的特殊性,以提高其航渡隐蔽性为出发点,基于通信侦测与防御进行探讨。     

基于区间数的第4代战斗机空战效能评估

根据第4代战斗机所具有的典型特征,建立了第4代战斗机的空战效能评估指标体系。采用区间数特征向量法确定了效能评估指标体系中的各指标的权重,给出了定量指标和定性指标的规范化方法,提出了采用区间数形式的加权和关系进行效能指标聚合的方法。最后,通过实例验证了所建立的空战效能评估指标体系的合理,评估方法的有效、可行。     

Research on the intermediate phase of 40CrMnSiB steel shell under different heat treatments

In this study, 40CrMnSiB steel cylindrical shells were tempered at 350, 500 and 600 ℃ to study the effect of tempering temperature on the dynamic process of expansion and fracture of the metal shell. A mid-explosion recovery experiment for the metal cylinder under internal explosive loading was designed, and the wreckage of the casings at the intermediate phase was obtained. The effects of different tempering temperatures on the macroscopic and microscopic fracture characteristics of 40CrMnSiB steel were studied. The influence of tempering temperatures on the fracture characteristic parameters of the recovered wreckage were measured and analyzed, including the circumferential divide size, the thick-ness and the number of the circumferential divisions. The results show that as the tempering temper-ature was increased from 350 to 600 ℃, at first, the degree of fragmentation and the fracture characteristic parameters of the recovered wreckage changed significantly and then became essentially consistent. Scanning electron microscopy analysis revealed flow-like structure characteristics caused by adiabatic shear on different fracture surfaces. At the detonation initiation end of the casing, fracturing was formed by tearing along the crack, which existed a distance from the initiation end and propagated along the axis direction. In contrast, the fracturing near the middle position consists of a plurality of radial shear fracture units. The amount of alloy carbide that was precipitated during the tempering process increased continuously with tempering temperature, leading to an increasing number of spherical carbide particles scattered around the fracture surface.     

Thermal and combustion behavior of Al-MnO2 nanothermite with poly(vinylidene fluoride -co- hexafluoropropylene) energetic binder

Fluoropolymers get increasing attention in energetic materials application due to the high fluorine content. To explore the effect of poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) on Al/MnO2 nanothermite, the samples with different contents are prepared and characterized by SEM, TG-DSC, XRD, and their ignition and combustion behavior are tested and recorded. The results show that P(VDF-HFP) as an energetic binder can combine the nanothermite components together, even exist in the gaps. The integrity of energetic materials has been improved. Thermal analysis shows that the addition of P(VDF-HFP) greatly changes the thermal reaction processes, and the exothermic peaks appear early, but the utilization of fuel and oxidizer is not efficient from the XRD results. Furthermore, the appropriate addition of P(VDF-HFP) can directly reduce the ignition energy threshold and increase the combustion time, which is necessary for the potential ignition charge application. The possible reasons for above phenomena are discussed and analyzed. This research provides a reference for improvement of thermite-based ignition charge formulation.     

岩土损伤复合体理论的应力应变合成模式

近年来,岩土损伤本构模型取得了长足的进步,但在岩土材料损伤的复合体理论的一个基本问题--复合体的两个组分的应力、应变合成模式上存在争议.从损伤力学的基础--连续介质力学的基本概念出发,对岩土损伤复合体理论应力、应变合成的合理模式进行了研究.得出了一般损伤情况下的岩土损伤复合体理论的应力、应变合成公式,给出了各向同性损伤情况下的简化公式,认为对于岩土损伤复合体理论不能简单地采用并联、串联假设.