GERMANY'S CURRENT AND FUTURE PLUTONIUM INVENTORY

In the past, Germany reprocessed a significant amount of its spent nuclear fuel, partly on its own territory but mostly as a customer of British and French reprocessing plants. In mid-2005, Germany stopped this practice, banning new transports of spent fuel for reprocessing—although the already-exported material would be allowed to be reprocessed and recycled in German reactors as mixed-oxide (MOX) fuel. In total, about 6,500 tonnes of heavy metal have been contracted for reprocessing, but a significant portion of this material has neither been reprocessed nor recycled as MOX fuel in German reactors. Due to the complex import-export history and the partly nontransparent information policy of the German government and utilities, a comprehensive and up-to-date plutonium balance for Germany is not publicly available. This report provides an assessment of Germany's plutonium inventory (stored domestically or abroad) based on open-source information. Special attention is paid to the issue of whether the entire inventory of separated plutonium can be completely irradiated in German nuclear reactors before the last of them are shut down in 2022. The authors conclude that Germany's stock of plutonium waiting to be recycled was about 12.2 tonnes as of 2010; this plutonium should be completely re-imported from the United Kingdom and France by 2017. Germany's MOX-consumption capacities should be sufficient to irradiate the remaining plutonium, although further delays are expected that could leave Germany with an inventory of separated (unirradiated) plutonium.     

无人机技术中国专利分布情况及其专利情报运用

无人机技术是近年兴起的一项涵盖领域宽、技术难度高、战场和市场应用前景均十分广阔的前沿技术.文章分析了1986年-2012年份期间在中国申请的、其专利名称、权利要求和摘要中包含有“无人机”、“无人驾驶飞机”或者“无人驾驶飞行器”等关键词的专利检索结果分布情况.文章对如何在国防科研中积极有效地运用专利情报以及加强科研过程中的保密工作提出了建议.     

漂浮式微型波力发电装置原理与结构

为了满足偏远岛屿小功率用电保障需求,根据波浪能特点,提出一种新型漂浮式微型波力发电装置。利用重锤惯性定心原理,建立浮动"机架",解决漂浮体内部相对固定问题;采用机-电直接转换系统,提高波浪能的利用效率;研究系统的原理与结构,分析系统的功能特点和主要运动参数。研究结果表明,漂浮式微型波力发电装置具有结构原理新颖、传动效率高、传动质量好与轻巧便携等优点。该研究为漂浮式微型波力发电装置的研发与应用奠定了基础。     

基于时频信号项的输电塔损伤识别柔度矩阵法

将悬臂结构损伤识别柔度矩阵法和振动时域响应信号时频分析方法相结合,利用柔度矩阵与结构参数间的线性关系,引入突卸荷载激励下振动响应的WVD时频分布信号项幅值向量,通过求解损伤系数方程来识别集中质量型输电塔结构的损伤位置和程度。算例分析表明,所提出的方法通过一次测量就能准确地识别出结构单个或多个损伤的程度,并具有良好的抗噪性。     

航空吊放声纳主动方式暴露距离研究

航空吊放声纳是反潜作战主要搜潜设备之一,其主动工作方式暴露范围也是搜潜战术运用的重要参数。基于均方声压声纳方程修正了相关参数,得到了声能声纳方程各项参数定义,结合高斯束射线Bellhop模型,研究了吊放声纳主动方式暴露距离估算方法,针对潜艇两种声纳类型工作特性,进行了仿真和分析。仿真结果表明,在潜艇侦察声纳工作时,吊放声纳主动方式暴露距离明显加大。     

再生冷却通道结构参数对碳氢燃料流量分配影响

以液体火箭发动机再生冷却技术为背景,采用数值模拟方法对Z-type型并联通道流量分配特性进行研究,分析了通道数、通道截面形状及入口汇流结构对流量分配特性的影响。研究结果表明:在冷却通道总流通面积相同的情况下,随着再生冷却系统通道数的增加,流量分配不均匀度系数从2.59%降低至0.5%,相同流通面积下增加通道数可以有效提高流量分配的均匀程度。通道截面形状对流量分配不均匀度系数影响不大,其影响主要表现在通道内部流体速度分布及换热面积上。从换热效果看,梯形截面构型要优于矩形构型。入口汇流结构倾斜角有利于流量的均匀性分布。该研究对于再生冷却通道结构设计具有一定参考价值。     

Kevlar fabric reinforced polybenzoxazine composites filled with silane treated microcrystalline cellulose in the interlayers: The next generation of multi-layered armor panels

The design of astonishing combinations of benzoxazine resins with various fillers is nowadays of great interest for high quality products, especially in ballistic armors. The objective of this study is to investigate a new hybrid material prepared as multi-layered composite plate by hand lay-up technique. Different composites were manufactured from Kevlar fabrics reinforced polybenzoxazine, which was filled with silane treated microcrystalline cellulose (MCC Si) at various amounts in the interlayers. The developed materials were tested for their flexural, dynamic mechanical and ballistic performance. The aim was to highlight the effect of adding different amounts of MCC Si on the behavior of the different plates. Compared to the baseline, the dynamic mechanical and bending tests revealed an obvious decrease of the glass transition of 21 °C and a notable increase in storage modulus and flexural strength of about 180 %and17%, respectively, upon adding 1% MMC Si as filler. Similarly, the ballistic test exhibited an enhancement in kinetic energy absorption for which the composite supplemented with 1% MCC Si had the maximal energy absorption of 166.60 J. These results indicated that the developed panels, with interesting mechanical and ballistic features, are suitable to be employed as raw materials to produce body armor.     

小子样条件下战斗部爆炸仿真数据可信性分析

高效毁伤战斗部试验次数受到严格控制,如何在小子样条件下分析仿真数据的可信性非常有必要。通过均匀试验得到了战斗部在地下目标腔室内部爆炸某点冲击波最大超压峰值,利用normplot及Lilliefors函数分析了仿真数据的分布特征,而后在已有检验方法的基础上,结合顺序统计量和均匀分布的特点提出了一种新的相容性验证思路。研究表明:该方法不受样本容量的限制,利用MATLAB程序编程可以快速判断仿真数据的可信性。     

探月飞船初次再入段纵程的解析预测方法

探月飞船升阻比较低,为实现长纵程飞行,必须采用跳跃式再入方式。在跳跃式再入轨迹在线规划或预测制导中,如何快速准确地预测初次再入段纵程是一个非常关键的问题。针对这一问题,研究提出一种解析预测方法:利用匹配渐进展开方法得到再入纵向运动方程的闭型近似解;将初次再入段轨迹分为三段,第一段采用高度作为积分自变量,并利用复合梯形公式得到纵程,第二段和第三段分别采用二次多项式来拟合阻力加速度-能量剖面,根据近似解结果反解出多项式系数,并将得到的阻力加速度倒数-能量函数进行积分,得到第二段和第三段的纵程;对解析预测方法的精度和计算效率进行分析,结果表明该方法计算精度较高,速度快,可用于跳跃式再入轨迹的在线规划和制导。     

并联波浪补偿系统的鲁棒控制方法

研究了基于绳牵引并联机构的新型波浪补偿系统的鲁棒控制方法。将环境作用力和不可测参数从动力学方程中分离出来,看作系统干扰,然后根据李亚普诺夫稳定性理论推导了控制律。针对绳索冗余的情况,提出了一种基于交互投影的绳索张力分布算法。当存在张力分布的可行解时,该算法能够得到远离张力限制边缘的"安全"最优解;当不存在可行解时,该算法能够得到满足张力限制条件的最佳近似解。为了提高鲁棒控制的实用性,还研究了负载惯性参数辨识方法。仿真结果表明,以上理论与方法对于波浪补偿系统是非常有效的。