摘要：A signal pre-processing method based on optimal variational mode decomposition(OVMD)is proposed to improve the efficiency and accuracy of local data filtering and analysis of edge nodes in distributed electromechanical ***,the singular points of original signals are eliminated effectively by using the first-order difference *** the OVMD method is applied for signal modal ***,correlation analysis is conducted to determine the degree of correlation between each mode and the original signal,so as to accurately separate the real operating signal from noise *** the basis of theoretical analysis and simulation,an edge node pre-processing system for distributed electromechanical system is ***,by virtue of the signal-to-noise ratio(SNR)and root-mean-square error(RMSE)indicators,the signal pre-processing effect is *** experimental results show that the OVMD-based edge node pre-processing system can extract signals with different characteristics and improve the SNR of reconstructed *** to its high fidelity and reliability,this system can also provide data quality assurance for subsequent system health monitoring and fault diagnosis.

摘要：在一致光滑的一致凸的Banach空间中,设计了一种收缩投影算法用以逼近变分不等式的解,并在紧算子减弱为连续算子的条件下,利用广义投影算子和K-K性质等技巧证明了该算法的强收敛性.所得结果是近期相关结果的改进与推广,其算法有重要应用.

摘要：为提高稠油井电加热系统的加热效率,解决油田中频电源加热运行控制主要依靠人工经验设置和低效的自动控制造成电能浪费的现状,本文设计了稠油电加热嵌入式控制装置。基于非嵌入式获取的油井生产电信号,以稠油开采电机的电功率为闭环反馈信号,获取油液最优温度的参考输入。在此基础之上,通过井口油液温度的微分反馈环节,改善温度迟滞效应,实现中频电源的节能优化控制。通过对嵌入式硬件核心电路模块的设计和主要软件功能的开发,不仅实现了稠油井电加热过程的动态控制,还实现了各项运行指标的现场及云端的实时监测。稠油井场试验分析表明,所设计的稠油电加热嵌入式控制装置符合井场节能安全的生产需求,节约能耗可达20%。

摘要：本文研究加权Toeplitz最小二乘问题的快速求解算法.首先,在增广线性系统的基础上,设计了一种用于求解此类线性系统的新型简单预条件子.其次,研究了迭代法的收敛性,并证明了预条件矩阵的所有特征值均是实数且非单位特征值位于某正区间.再次,研究了预条件矩阵的特征向量分布和最小多项式的维数.最后,相关数值实验表明新型预条件子比一些已有的预条件子更有效.

摘要：A series of shape-persistent polyphenylene dendritic C_(60)derivatives as the electron transport materials were designed and synthesized via a catalyst-free Diels-Alder[4+2]cycloaddition *** increasing hyperbranched scaffolds could effectively enhance the solubility;notably,both first and second generation dendrimers,C_(60)-G1 and C_(60)-G2,demonstrated more than 5 times higher solubilities than pristine C_(60).Furthermore,both simulated and experimental data proved their promising solution-processabilities as electron-transporting layers(ETLs)for perovskite solar *** a result,the planar p-i-n structural perovskite solar cell could achieve a maximum power conversion efficiency of 14.7%with C_(60)-G2.

摘要：We propose a formation control strategy for multiple unmanned aerial vehicles （multi-UAV） based on second-order consensus, by introducing position and velocity coordination variables through neighbor-to-neighbor interaction to generate steering commands. A cooperative guidance algorithm and a cooperative control algorithm are proposed together to maintain a specified geometric configuration, managing the position and attitude respectively. With the whole system composed of the six-degree-of-freedom UAV model, tile cooperative guidance algorithm, and the cooperative control algorithm, the formation control strategy is a closed-loop one and with full states. The cooperative guidance law is a second-order consensus algorithm, providing the desired acceleration, pitch rate, and heading rate. Longitudinal and lateral motions are jointly considered, and the cooperative control law is designed by deducing state equations. Closed-loop stability of the formation is analyzed, and a necessary and sufficient condition is provided. Measurement errors in position data are suppressed by synchronization technology to improve the control precision. In the simulation, three-dimensional formation flight demonstrates the feasibility and effectiveness of the formation control strategy.

摘要：研究影响电催化氧还原反应活性的因素对于合理设计高效的氧还原反应催化剂至关重要。调节催化剂电子结构通常被用于精确调控电催化氧还原反应活性。然而,该反应发生在液/气/固界面,很少有报道调控分子催化剂的亲疏水性来提高其催化活性。在此,我们报道了两种钴卟啉NO_(2)-CoP(5,10,15,20-四(4-硝基苯基)钴卟啉)和5F-CoP(5,10,15,20-四(五氟苯基)钴卟啉)并研究了其电催化氧还原反应性能。通过同时调控meso-位取代基的电子结构和亲水性能,NO_(2)-CoP显示出比5F-CoP更高的电催化氧还原反应活性,其半波电位向阳极方向移动近60 mV。NO_(2)-CoP比5F-CoP具有更好的亲水性。理论计算表明,NO_(2)-CoP比5F-CoP更容易有效地与O_(2)分子结合形成Co^(Ⅲ)-O_(2)^(·-)。这项工作提供了一个简单而有效的策略,通过使用吸电子和亲水取代基来提高钴卟啉的氧还原反应活性。该策略对于设计和开发其他用于电催化的分子催化剂体系也具有重要的启发意义。

摘要：通讯技术不断升级以及移动设备的快速发展极大改善了人们生活,但也带来了电磁干扰和信息安全问题.因此,亟需开发高性能电磁屏蔽材料来抑制电磁辐射和阻止信息泄露.研究发现,在外力作用下填料的自取向行为有助于实现聚合物基复合材料电磁屏蔽性能的提升,因此如何在聚合物基体中构筑有效的填料取向结构正成为电磁屏蔽材料研究的热点.本文首先关注外场诱导复合材料内导电网络的构建策略.随后,梳理了利用外场诱导无机填料取向制备聚合物基电磁屏蔽复合材料的研究进展,其中外场包括温度场、静电场、重力场、机械力场和磁场.值得注意的是,基于外场诱导制备的独特结构与电磁波之间的特殊响应关系通过精选的案例被进一步剖析.最后,提出外场辅助制备聚合物基电磁屏蔽复合材料各自亟待解决的关键科学和技术问题,并对未来的发展方向进行了理性预测.本文讨论的方法和提出的策略有望为高性能聚合物基电磁屏蔽复合材料的创新设计提供一些指导意见.

摘要：具有高且稳定离子输运特性的二维层状薄膜在纳米流体器件中具有广泛的应用,但是它们的构建仍然是一个相当大的挑战.本文设计并开发了一种超稳定的芳纶纳米纤维/石墨复合薄膜,其内部包含大量的一维和二维纳米受限空间,可以实现超快的离子传输.这种薄膜不仅具有良好的柔性和可拓展性,同时还表现出优异的力学性能,即使在水中浸泡90天仍具有高的拉伸强度(~115.3 MPa).并且该薄膜在低的盐浓度下具有表面电荷控制的离子输运特性,在10^(-4)mol/LKCl浓度下,其离子电导率相对于原始KCl溶液提高了16倍.最重要的是,即使在酸、碱、乙醇等极端环境中浸泡30天以上,薄膜的结构和离子电导率仍保持稳定.分子动力学模拟进一步揭示了薄膜的超稳定性是源于纳米纤维内部强大的链间作用以及纳米纤维与石墨纳米片之间强大的界面相互作用.这种柔性、可扩展、超稳定的芳纶纳米纤维/石墨复合薄膜可能为先进的纳米流体器件在不同极端工作环境下的应用提供一种有效的策略.

摘要：电流互感器(current transformer,CT)的暂态饱和容易导致继电保护误动作,寻求暂态饱和的原因和防范保护误动的对策特别需要建立CT的分析模型,然而该模型及其参数的构建如何体现实际运行一直是个研究难点。该文首先基于J-A理论给出了CT分析模型,分析了该模型的数值计算思路。然后针对J-A模型中描述不同励磁曲线轨迹的关键参数,研究了以磁感应强度B为优化目标的引力搜索辨识方法。最后,精心设计了330k V系统P级CT的6~48k A大通流动态模拟试验,测试表明CT的J-A模型以及所提的参数辨识算法是有效的、正确的并且符合工程实际。