一种基于抽取LMS的距离旁瓣抑制方法

在噪声雷达中，传统相关处理方法的距离旁瓣受到时宽带宽积的限制，在有限相关处理时间内得到的距离旁瓣较高，会造成微弱目标被强目标、杂波旁瓣淹没的现象。提出一种基于抽取最小均方（Least Mean Square,LMS）滤波的噪声雷达旁瓣抑制方法，将LMS滤波器的系数作为距离压缩结果，从而获取较低的距离旁瓣。对该方法的性能进行了理论分析，并通过数字仿真验证了算法的有效性和理论分析的正确性。     

Computational and experimental study of dental resin composites with high filler content

Journal of Materials Science - Nanocomposites have been used in various industries due to their excellent properties. For some of them, high filler content (over 50 wt%) is beneficial to improving...     

西南地区乡镇共墙建造砖混结构房屋典型震害与结构性能改进措施

多年来，西南地区龙门山断裂带发生多次破坏性地震，影响范围较广，导致该地区乡镇居民有大量带震害损伤共墙建造砖混结构房屋留存使用，此类建筑结构使用安全问题需高度关注。通过对该地区乡镇常见共墙建造砖混结构房屋的结构特征及建造技术进行探讨，开展该类型房屋承重墙、预制楼板、楼梯、附属结构典型震害、修复与使用情况调查分析，总结典型共墙建造砖混结构房屋的破坏特点，提出该类型房屋抗震能力评估方法及结构性能改进措施建议。     

Gelling behavior of MgAl2O4 slurries with a common dispersant

MgAl₂O₄ transparent ceramics were shaped by a commonly used polyacrylic acid (PAA), which acted as both dispersant and gelling agent. The spinel slurries were prepared by ball-milling MgAl₂O₄ powder, PAA, and water in an attrition mill. The gelling of slurries happened at room temperature in air atmosphere without any other organic additive. The gelling mechanism was the formation of chelates between Mg²⁺ and carboxyl groups (-COO⁻) of PAA. The frequency-based testing method was applied to investigate the gelling process of the as-prepared slurry. In addition, a novel in situ characterization method based on a modified indentation testing was invented to better understand the strengthening of the wet green body with time and to guide when demolding could be carried out. After sintering, transparent MgAl₂O₄ ceramics with high in-line transmittance were resulted.     

Memory-based dynamic event-triggered control for networked interval type-2 fuzzy systems subject to DoS attacks

In this article, the memory-based dynamic event-triggered controller design issue is investigated for networked interval type-2 (IT2) fuzzy systems under non-periodic denial-of-service (DoS) attacks. For saving limited network bandwidth, a novel memory-based dynamic event-triggered mechanism (DETM) is proposed to schedule data communication. Unlike existing event-triggered generators, the developed memory-based DETM can utilize a series of newly released signals and further save network resources by introducing interval dynamic variables. Moreover, to improve design flexibility, an IT2 fuzzy controller with freely selectable fuzzy rule number and premise membership functions (MFs) is synthesized. Then, a new switched time-delay system with imperfectly matched MFs is established under the consideration of memory-based DETM and DoS attacks simultaneously. Besides, based on the property of MFs, the boundary information of membership grades and slack matrices are introduced in the stability analysis. Furthermore, by using a piecewise Lyapunov–Krasovskii method, membership-functions-dependent criteria are deduced to ensure the asymptotic stability of built fuzzy switched systems. Finally, the effectiveness of proposed control strategies is demonstrated by simulation examples.     

基于强度场的八球万向节内套结构与静强度设计匹配研究

为了对八沟道等速万向节内套进行结构和静强度设计,从钢球选型出发,对八沟道等速万向节内套进行了结构参数正向设计.对内套危险截面进行了全场静强度设计,以理想静强度场为目标,定量匹配了危险截面静强度的材料、热处理,并对全场静强度设计进行了定量评价.使用MTS静扭转试验机对等速万向节总成进行了静强度扭转试验,并用显微硬度计对内套进行了显微硬度试验以验证理论,结果表明按照基于强度场的机械结构和零部件的静强度设计与匹配方法设计的八沟道等速万向节星形套能够满足强度和功能需求.     

锂离子电池石墨负极放热反应研究

采用差示扫描量热仪(DSC)对满嵌锂态石墨负极在50～400℃之间出现的放热反应进行了研究.对不同荷电状态(SOC)的负极进行DSC、扫描电镜(SEM)和X射线衍射(XRD)分析以研究放热反应发生的过程.对负极中各物质之间可能发生的反应也均使用DSC进行分析.最终得出石墨负极各放热反应归属:100～120℃为SEI膜分解.200～270℃为锂与电解液的反应,270～300℃为锂与羧甲基纤维素钠(CMC)的反应以及电解液的分解反应,300℃以上放热尖峰为锂与石墨的反应.