爆炸成型弹丸贯穿靶板靶后破片空间分布模型

深空撞击载荷对探测小天体内部物质成分和结构特性具有重要意义,因此,在考虑爆炸成型弹丸(explosively formed projectile, EFP)可变截面的特性和区分靶后破片来源的基础上,建立了EFP贯穿靶板靶后破片空间分布模型。在靶板厚度30 mm至70 mm、EFP着靶速度1 650 m/s至1 860 m/s的条件下,该模型可以定量预测靶后破片云中各个破片的速度、质量、数量与空间位置的关系。结果表明,相对速度总是随相对空间位置的增加而呈线性增加,相对质量、相对数量总是随相对空间位置的增加而呈幂函数增加。     

Economic Competition and Nuclear Cooperation

The number of bilateral nuclear cooperation agreements surged during the “nuclear renaissance” of the past decade. This proliferation is only partially explained by the prevailing approaches that focus on strategic imperatives. To supplement these explanations, this study draws on neoliberal models of economic competition to posit that bilateral agreement negotiations also exhibit conditions of “uncoordinated interdependence” and maneuvering to gain market share. Case evidence suggests the contours of supplier state bids for civilian assistance are determined at least as much by considerations about economic competition as they are by positive strategic goals. In addition, this study identifies several cases of cooperation where there appears to be little or no strategic motive for export agreements. The study concludes that patterns of economic competition and the influence of peers in defined competitive spaces alter material payoffs and impact policies. It also identifies a surprising role for principled restraint in dampening strategic and economic competition in some dyads.     

基于能源互联网背景的储能二次电池技术发展分析

能源互联网是在现有配电网基础上,融合新能源技术和互联网技术,将分布式能源采集装置和分布式能源储存装置联合发展起来的新技术,对于优化能源结构和提高能源利用具有重要的意义。文章以能源互联网对储能电池的需求为背景,首先归纳了能源互联网对于储能电池的要求,在此基础上重点分析了多种可应用于能源互联网的储能电池的性能与特点,并对其未来发展趋势进行了展望。     

基于营区精、气、神文化表达的自然仿生设计

精、气、神文化是营区规划设计的核心.自然仿生设计为营区精、气、神文化的表达提供了独特而有效的方式.通过对营区精、气、神文化的解读,发掘出自然仿生的3个层面,即“形”之仿生,“意”之仿生和“结构”之仿生.在营区规划设计中,当自然仿生的这3个层面得到有效表达,实现有机统一,营区就会产生独特的文化气质与魅力,从而体现其精、气、神特色,展现部队的“军营魂”.     

基于随机拟合的悬浮式深弹弹阵特征建模＊

通过分析悬浮式深弹发射后在空中的弹道特性,建立了深弹弹着点坐标的计算模型。采取蒙特卡洛方法,分别对舰艇六自由度状态下,单管和六联装火箭深弹的弹着点坐标进行了仿真计算,对弹着点的分布规律进行了研究,并得出弹着点的联合密度函数。结果表明,在发射参数存在正态扰动时,弹着点散布区域均呈椭圆形分布,弹着点坐标均仍服从正态分布。     

Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN) (TEGDN propellants) to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm³. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.     

超宽带强电磁防护能量选择表面设计

为应对强电磁脉冲对电子信息系统的威胁,设计了一种具备收发兼容特性的超宽带强电磁防护能量选择表面,有效拓展了能量选择表面的工作带宽和工作频率,可为L、S、C波段的超宽带用频装备提供不低于14 dB的防护效果。该能量选择表面是一种周期结构,每个单元包含一对箭头形结构和一个开关二极管,可根据外界辐照电磁波的能量密度自适应切换反射或透波状态,从而实现强电磁防护与工作信号收发兼容。仿真研究表明,这一新型能量选择表面在L、S、C波段的插入损耗小于1 dB,强电磁防护能力达到22 dB。在波导中对设计的样件进行了性能验证,结果显示,该样件在波导中的平均插入损耗为1 dB,防护能力达到了14 dB,初步验证了设计结构的低插入损耗和高防护特性。     

顾及地磁影响的GNSS电离层层析不等像素间距算法

突破传统全球导航卫星系统(Global Navigation Satellite System, GNSS)层析反演研究忽略地球磁场对电离层变化活动的影响,同时顾及不同电离层高度电子密度变化较大的影响,提出在地磁坐标系下建立电离层高度方向上不等像素间距的GNSS层析反演方法。在此基础上,通过建立新的电离层层析迭代松弛因子,提高GNSS电离层电子密度层析反演结果精度。利用IRI—2007电离层模型、GNSS实测数据与电离层测高仪数据,从模拟验证和实测数据对比两方面,反演统计了不同层析算法估算的峰值电离层电子密度误差、电子密度剖面结果平均绝对百分比误差及均方根误差,验证了顾及地磁影响的GNSS电离层层析不等像素间距算法的有效性。     

纤维缠绕复合材料夹芯圆柱体高应变率压缩吸能机理

为研究纤维缠绕复合材料夹芯圆柱体吸能元件在高应变率冲击压缩载荷作用下的变形损伤模式和能量吸收机理,采用ABAQUS商用有限元软件和分离式Hopkinson压杆装置开展数值模拟分析和试验验证研究。对比分析宏观力学响应规律和微观损伤破坏机理,可知吸能结构元件在高应变率压缩载荷下的力学响应具有典型的弹塑性特征,内部芯材主要产生压缩塑性损伤,而表层复合材料沿环向产生拉伸断裂破坏。研究表明,该吸能元件冲击压缩吸能特性优异,可满足水下结构平台的冲击防护和浮力储备要求。     

Cross-linking density and aging constitutive model of HTPB coating under prestrain thermal accelerated aging

In order to study the cross-linking density and aging constitutive relationship of HTPB coating during storage, the thermal accelerated aging tests at 0%, 3%, 6% and 9% prestrains were carried out. The cross-linking density of HTPB coating at different aging stages were tested using low-field ¹H NMR and the variation of cross-linking density was analyzed. The aging model of cross-linking density considering the chemical aging and the physical stretching factors was established. The uniaxial tensile tests were carried out on HTPB coating at different aging stages and the cross-linking density was introduced into Ogden hyperelastic constitutive model as a characterization parameter of correction coefficient. Combined with uniaxial tensile test results, a prestrain aging constitutive model of HTPB coating was established. The results show that the cross-linking density of HTPB coating increases rapidly at first and then slowly with the increase of thermal accelerated aging time without prestrain. Under prestrain conditions, the cross-linking density of HTPB coating decreases at the early stage, and increases rapidly at first and then slowly at the middle and late stages of thermal accelerated aging. The correlation coefficients of aging model of cross-linking density and aging constitutive model with test results are R > 0.9500 and R > 0.9900 respectively, which can be used to accurately describe the cross-linking density and aging constitutive relationship of HTPB coating under prestrain accelerated thermal aging conditions.