深水连续刚构桥地震响应分析

以某深水刚构桥为例,以附加质量的形式考虑墩水耦合效应的影响,运用大型通用有限元软件ADINA,建立结构动力有限元模型,进行动力时程分析。比较考虑墩水耦合效应和不考虑墩水耦合效应下的内力和位移。结果表明：考虑墩水耦舍效应时比不考虑墩水耦合效应时的内力和位移都明显增大,并且应同时考虑外域水与内域水对高墩的共同作用。     

基于FDM-PFM耦合方法的刚性桩复合地基性能

为揭示褥垫层颗粒材料的力学本质,深入研究其对刚性桩复合地基性能的影响,开发了有限差分-颗粒流(FDM-PFM)耦合方法,建立了刚性桩复合地基静载试验耦合模型;将耦合模型计算结果与某高层建筑结构现场静载试验结果进行了对比,吻合良好,证明该耦合方法有效,材料宏观、细观参数取值正确.并进一步模拟分析了不同褥垫层材料对刚性桩复合地基性能的影响,结果表明:随褥垫层刚度增大,沉降减小,桩土应力比增大,桩顶对褥垫层刺入量减小;不同褥垫层材料桩顶负摩阻区范围为中粗砂0.30L、碎石0.25 L、级配砂石0.20 L(L为桩长);随褥垫层刚度增大,负摩阻力减小,桩身轴力则增大.     

脉冲磁场杀菌技术研究进展

脉冲磁场杀菌处理技术是一项很有发展前景的新技术。介绍了脉冲磁场杀菌技术的特点,综述了脉冲磁场杀菌技术在水处理和食品工业方面的应用和理论研究进展,并展望了脉冲磁场杀菌技术的应用前景。     

脉冲磁场对高速钢刀具材料微观硬度的影响

研究脉冲磁场对W9Mo3Cr4V高速钢刀具材料微观硬度的影响规律. 利用自行构建的磁处理试验平台对高速钢试样进行定向脉冲磁化处理. 研究不同的脉冲磁场强度、磁场频率和磁化时间对高速钢材料微观硬度的影响规律,通过观察高速钢材料金相组织,分析脉冲磁场作用下高速钢材料的微观组织变化机制. 试验结果表明,在选择合适的脉冲磁化工艺参数条件下,高速钢材料的微观硬度能够明显提高. 脉冲磁场作用促使金属材料中一部分残余奥氏体转化为硬而脆的马氏体,使马氏体含量升高,材料组织变得均匀.      

含有三蝶烯结构噻吩寡聚物(英文)

本文报道了3个噻吩寡聚物,在它们的侧链都含有三蝶烯结构.这些新型的化合物经过5步反应获得,其中包括区域选择性的溴化反应,Stille偶联反应,路易斯酸催化的Diels-Alder环加成反应.这些新型化合物可以用来合成以噻吩或蝶烯为单元的聚合物.     

Big data analysis of the human brain’s functional interactions based on fMRI

The human brain is a huge, complex system generating brain activity. The exploration of human brain function using functional magnetic resonance imaging （fMRI） is a promising method to understand brain activity. However, the complexity of the big data generated by fMRI facilitates the analysis of various levels of human brain activity, such as the distribution of neural represen- tations, the interaction between different regions, and the dynamic interaction over time. These different levels can depict distinct prospects of the human brain activity, and considerable progress has been achieved. In the future, more big data analysis methods combining advances in computer science, including larger-scale computing, machine learning, and graph theory, will promote the understanding of the human brain.     

Novel laminated multiferroic heterostructures for reconfigurable microwave devices

Voltage tuning of magnetism is fundamentally and technically important for fast, compact and ultra-low power electronic devices. Multiferroic heterostructures,simultaneously exhibiting distinct ferroelectric and ferromagnetic properties, have caught a lot of attentions because of the capability of controlling magnetism by a voltage via a strain-mediated magnetoelectric（ME） coupling. In these materials, a voltage-induced strain is involved to create an effective magnetic field and change ferromagnetic resonance frequency in the coupled ferromagnetic phases through magnetoelastic interactions. Therefore, the devices made of such materials are compact, ultra-fast and energy efficient,providing new functionalities for microwave components.This paper will review the recent progress of multiferroics and their applications in microwave devices from different aspects, including the creation of the novel laminated multiferroic heterostructures with a strong ME coupling, the realization of the multiferroics based on tunable microwave signal processors and the investigation of nonvolatile tuning of microwave properties using ferroelastic domain switching in multiferroic heterostructures. These tunable multiferroic heterostructures and devices offer great opportunities for realizing the next generation of tunable magnetic microwave components, ultra-low power electronics and spintronics.     

Research progress in ZnO single-crystal: growth,scientific understanding,and device applications

Zinc oxide, a wide band-gap semiconductor, has shown extensive potential applications in high-efficiency semiconductor photoelectronic devices, semiconductor photocatalysis, and diluted magnetic semiconductors. Due to the undisputed lattice integrity, ZnO single crystals are essential for the fabrication of high-quality ZnO-based photoelectronic devices, and also believed to be ideal research subjects for understanding the underlying mechanisms of semiconductor photocatalysis and diluted magnetic semiconductors. This review, which is organized in two main parts, introduces the recent progress in growth, basic characterization, and device development of ZnO single crystals, and some related works in our group. The first part begins from the growth of ZnO single crystal, and summarizes the fundamental and applied investigations based on ZnO single crystals. These works are composed of the fabrication of homoepitaxial ZnO-based photoelectronic devices, the research on the photocatalysis mechanism, and dilute magnetic mechanism. The second part describes the fabrication of highly thermostable n-type ZnO with high mobility and high electron concentration through intentional doping. More importantly, in this part, a conceptual approach for fabricating highly thermostable p-type ZnO materials with high mobility through an integrated three-step treatment is proposed on the basis of the preliminary research.     

高速永磁电机转子关键性能研究

从电磁和机械两方面综合考虑,基于弹性力学理论,运用有限元分析方法建立护套和永磁体应力计算模型,计算永磁体和护套的基本尺寸和过盈量.并利用轴对称的有限元模型推算出转子系统的动力学方程,进而通过有限元仿真分析了转子临界转速和振动模态以及刚度对临界转速的影响.     

回流法制备MnFe_2O_4纳米晶及磁性能

以NaOH为沉淀剂,通过一种简单的低温回流法制备了MnFe2O4纳米晶.采用XRD、SEM、FESEM、FTIR和VSM等手段对MnFe2O4纳米晶尺寸、晶相结构和磁性能进行了分析表征.结果表明,所制备的MnFe2O4纳米晶为尖晶石相结构,晶粒尺寸随着反应温度的升高而增大,从50℃的10 nm增大到90℃的22 nm;样品的饱和磁化度随温度的升高而增大.