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THE ENDPOINT ESTIMATE FOR FOURIER INTEGRAL OPERATORS

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Acta Mathematica Scientia 2021年第2期41卷 426-436页

作者： guangqing wang Jie YANG Wenyi CHEN School of Mathematics and Statistics Wuhan UniversityWuhan 430072China College of Mathematics and System Science Xinjiang UniversityXinjiang 830046China

Let T_(a,φ)be a Fourier integral operator defined by the oscillatory integral T_(a,φ)u(x)=1/(2π)^(n)∫_(R^(n))^e^(iφ(x,ξ))a(x,ξ)(u)(ξ)dξ,where a∈S_(e,δ)^(m)andφ∈Φ^(2),satisfying the strong non-degenerate *** is shown that if0<(e)≤1,0≤δ<1 and m≤e^(2)-n/2,thenT_(α,φ)is a bounded operator from L^(∞()R^(n))to BMO(R^(n)).

关键词： Fourier integral operators phase function BMO spaces

Zirconium content induced mitigation of mechanical anisotropy in 2:17 type SmCo magnets

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Journal of Rare Earths 2020年第2期38卷 182-187页

作者： Guanghui Yan Zhuang Liu Yanping Feng Weixing Xia Chaoyue Zhang guangqing wang Aru Yan University of Chinese Academy of Sciences Beijing 100049China Laboratory of Rare Earth Magnetic Functional Materials Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China CAS Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China

The mitigation of mechanical anisotropy is observed in 2:17 type SmCo magnets by adjusting the Zr content This behavior is supposed to be closely related to the density of lamellar phase,the density of which is enhanced obviously with increasing Zr *** other reasons which could cause the reduction of the mechanical anisotropy is discussed from the Zr-rich impurity phase to the atom substitutions and crystal lattice *** observation of crack in nano scale that dearly forms angles of 60° and 90° with respect to the lamellar phase,indicates that the probable cleavage planes are crystal faces(1011) and(1010).The results of investigation can deepen the understanding of mechanical anisotropy and cleavage fracture in the SmCo magnets.

关键词： 2 type SmCo magnet Mechanical anisotropy Cleavage plane Lamellar phase Rare earths

Doping-driven dual heterogeneous interfacial structures boosting the durability of industry-compatible water splitting at high current density

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Science China Chemistry 2024年第10期67卷 3468-3481页

作者： Chunming Yang Lihai Zhou Zhijie Kong Xiang Li wangchuan Zhu guangqing wang Yanzhong Zhen Feng Fu Yucang Liang Research Institute of Comprehensive Energy Industry Technology College of Chemistry&Chemical EngineeringYan’an UniversityYan’an 716000China Henan Key Laboratory of Crystalline Molecular Functional Materials Green Catalysis CenterCollege of ChemistryZhengzhou UniversityZhengzhou 450001China Institut für Anorganische Chemie Eberhard Karls UniversitätTübingen 72076Germany

Developing highly stable electrocatalysts under industry-compatible current densities(>500 mA cm^(-2))in an anion-exchange membrane water electrolyzer(AEMWE)is an enormous challenge for water ***,based on the results of density function theory calculations,a dual heterogeneous interfacial structured NiSe/Fe-Ni(OH)_(2)catalyst was subtly designed and successfully prepared by electrodepositing Fe-doped Ni(OH)_(2)on NiSe-loaded nickel foam(NF).Fe doping-driven heterogeneous structures in NiSe/Fe-Ni(OH)_(2)markedly boost catalytic activity and durability at industrially compatible current densities in single hydrogen and oxygen evolution reactions under alkaline *** particular,NiSe/Fe-Ni(OH)_(2)shows a negligible performance loss at 600 mA cm^(-2)at least 1,000 h for overall water splitting,a distinguished long-term durability acting as AEMWE electrodes at 600 mA cm^(-2)and 1 A cm^(-2)at 85℃for at least 95 *** to Fe doping-induced strong synergetic effect between Ni and Fe,dual heterostructure-promoted charge transfer and redistribution,abundant catalytic active sites,and improvement of stability and durability,a mechanism of Fe doping-driven heterogeneous interfacial structurepromoted catalytic performance was *** study provides a successful example of theory-directed catalyst preparation and pioneers a creative strategy for industry-compatible water splitting at high current density.

关键词： doping-induced heterojunction structure NiSe/Fe-Ni(OH)_(2) large current density anion-exchange membrane industrycompatible water electrolysis

Investigation of 3D Dirac semimetal supported terahertz dielectric-loaded plasmonic waveguides

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Communications in Theoretical Physics 2022年第12期74卷 130-137页

作者： Yubo Liang guangqing wang Yan Cheng Duo Cao Dejun Yang Xiaoyong He Fangting Lin Feng Liu Department of Physics Mathematics&Science CollegeShanghai Normal UniversityNo.100 Guilin RoadShanghai 200234China Shanghai Normal University Key Lab Submillimeter AstrophysicsNo.100 Guilin RoadShanghai 200234China

The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM layer,the fiber shape and operation *** results indicate that the shape of dielectric fiber affects the hybrid mode significantly,on the condition that if ax(the semi-minor axis length of the dielectric semi-ellipse)is relatively small,the fiber shows good mode confinement and low loss simultaneously,and the figure of merit reaches more than *** propagation property can be manipulated in a wide range by changing the Fermi level of 3D DSM,*** the Fermi level varies in the range of 0.05 eV–0.15 eV,the propagation length changes in the range of 9.073×10^(3)–2.715×10^(4)μm,and the corresponding modulation depth is 66.5%.These results are very helpful to understand the tunable mechanisms of the 3D DSM plasmonic devices,such as switchers,modulators,and sensors.

关键词： terahertz waves 3D Dirac semimetal surface plasmons tunable

压电智能主动构件等效机电耦合动力学模型及其特性研究

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中国机械工程 2008年第2期19卷 154-159页

作者：王光庆浙江工商大学杭州310018

介绍了一种采用压电元件作为致动器和传感器的集成式智能主动构件。提出了一种将复合静态刚度和无网格相结合的方法,基于力学等效思想,利用虚功原理和Galerkin方法建立了主动构件的等效机电耦合动力学模型,并对该模型进行了数值仿真,验... 详细信息

介绍了一种采用压电元件作为致动器和传感器的集成式智能主动构件。提出了一种将复合静态刚度和无网格相结合的方法,基于力学等效思想,利用虚功原理和Galerkin方法建立了主动构件的等效机电耦合动力学模型,并对该模型进行了数值仿真,验证了该模型的正确性;另外,对该构件的致动特性和传感特性进行了仿真分析与实验研究,结果表明:该压电智能主动构件具有输出位移大、驱动电压低、稳定性高以及传感特性良好等优点,适用于空间大型柔性结构的振动主动控制。

关键词：压电智能主动构件机电耦合动力学模型特性分析

The effects of modulation period,modulation ratio,and deposition temperature on microstructure and mechanical properties of ZrB_2/W multilayers

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Science China(Technological Sciences) 2010年第9期53卷 2350-2354页

作者： LIU MengYin,TAN Ming,LIU guangqing,wang HaiYuan,XUE FengYing,DENG XiangYun & LI DeJun College of Physics and Electronic Information Science,Tianjin Normal University,Tianjin 300387,China College of Physics and Electronic Information Science Tianjin Normal University Tianjin China

Monolithic ZrB2,W coatings and ZrB2/W multilayers with different modulation periods and modulation ratios were synthesized by ion beam assisted deposition at room temperature and 400°C.X-ray diffraction (XRD),scanning electron microscopy (SEM),surface profiler,and nanoindention were employed to investigate the influences of the deposition temperature and the modulation period on the growth,textures,interface structure,and mechanical properties of the *** results indicated that the multilayer with modulation period of 13 nm synthesized at room temperature possessed a higher hardness of 23.8 *** temperature gave a significant contribution to mechanical property *** 400°C-deposition temperature led to a maximum hardness and elastic modulus value of 32.1 and 399.1 GPa for ZrB2/W multilayer with a modulation period of 6.7 *** critical load increased to 42.8 mN and residual stress decreased to -0.7 GPa.A higher deposition temperature can cause an increase in interfacial atomic mixture and mobility of surface species,which induceds an increase in areal atomic density and dislocation *** results as well as small nanoscale grain sizes should be related to hardness increase.

关键词： ion beam assisted deposition nanoscale multilayers modulation period modulation ratio deposition temperature hardness

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超声波电动机胶粘技术及其对定子特性的影响

机械工程学报 2006年第9期42卷 91-96页

作者：王光庆沈润杰郭吉丰浙江大学电气工程学院杭州310027

针对行波型超声波电动机定子压电陶瓷(Piezoelectric,PZT)的胶粘问题,通过对定子的机电耦合效应有限元动力学模型的分析与计算,研究了胶粘层材料特性、厚度对超声波电动机定子振动特性的影响。重点分析不同激励条件下定子边缘缺胶和夹... 详细信息

针对行波型超声波电动机定子压电陶瓷(Piezoelectric,PZT)的胶粘问题,通过对定子的机电耦合效应有限元动力学模型的分析与计算,研究了胶粘层材料特性、厚度对超声波电动机定子振动特性的影响。重点分析不同激励条件下定子边缘缺胶和夹有气泡对胶层的抗剪切能力和定子振动特性的影响;分别从改进电动机定子结构和PZT粘结工艺方面探讨了提高胶粘层抗剪切能力的措施,确定了胶层最佳参数和电动机定子胶粘工艺及结构优化设计思想。结果表明:胶层厚度对电动机定子频率影响不大,但对其振动特性的影响较大,在保证可靠的粘结强度下降低胶层厚度有利于提高电动机性能。基于该工艺和设计思想研制的直径80 mm行波型超声波电动机性能稳定,堵转力矩达到1．2 N·m,空载转速80 r／min,研究结果有助于超声波电动机的产业化。

关键词：超声波电动机胶粘层振动特性有限元模型

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压电陶瓷对超声波电动机定子特性的影响

机械工程学报 2010年第4期46卷 8-14,21页

作者：王光庆沈润杰郭吉丰浙江工商大学信息与电子工程学院杭州310018 浙江大学电气工程学院杭州310027

压电陶瓷(Piezoelectric ceramic,PZT)是组成超声波电动机定子的核心元件,其性能的优劣将直接影响超声波电动机的输出性能。为了研究PZT对超声波电动机定子特性的影响,利用有限元法建立超声波电动机自由定子的机电耦合动力学模型,利用... 详细信息

压电陶瓷(Piezoelectric ceramic,PZT)是组成超声波电动机定子的核心元件,其性能的优劣将直接影响超声波电动机的输出性能。为了研究PZT对超声波电动机定子特性的影响,利用有限元法建立超声波电动机自由定子的机电耦合动力学模型,利用该模型重点研究PZT厚度、极化分区形式、极化不均匀性以及PZT开路和短路条件时对定子动态特性的影响,并提出基于能量的PZT极化分区形式、极化不均匀性对定子动态特性影响程度的评价方法。采用自然对流传热问题的牛顿冷却定律和热容理论,建立超声波电机定子的温度特性理论模型,基于该模型研究PZT材料介电损耗对电动机定子的温度特性影响。研究结果表明:电动机定子模态频率随PZT厚度的增大而增加,而定子表面质点的振动幅值则随PZT厚度的增加而减小;PZT开路时的定子模态频率比短路时的模态频率大;改进PZT极化分区形式和极化不均匀性均可以提高超声波电动机自由定子的动态特性。基于该研究结果制作的直径10.4mm行波型超声波电动机性能稳定,堵转力矩达到9.5mN·m,空载转速1000r/min,研究结果有助于超声波电动机的产业化。

关键词：超声波电动机压电陶瓷定子特性有限元模型能量温度

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基于能量等效的行波型超声波电动机解析模型

机械工程学报 2008年第2期44卷 74-81页

作者：王光庆陆国丽郭吉丰浙江工商大学信息与电子工程学院杭州310018 杭州电子科技大学计算机工程学院杭州310018 浙江大学电气工程学院杭州310027

提出一种基于能量等效的行波型超声波电动机稳态特性分析计算的解析模型。首先通过能量等效原则将压电复合定子环简化成复合等直梁模型,综合考虑压电复合定子的转动惯量和剪切变形的影响,利用铁木辛柯梁振动理论得到电动机定子振动的频... 详细信息

提出一种基于能量等效的行波型超声波电动机稳态特性分析计算的解析模型。首先通过能量等效原则将压电复合定子环简化成复合等直梁模型,综合考虑压电复合定子的转动惯量和剪切变形的影响,利用铁木辛柯梁振动理论得到电动机定子振动的频率方程和强迫振动稳态解;其次,对电动机定、转子接触面的滑动状况进行分析,利用弹性接触理论确定了定、转子接触面的力传递模型和效率表达式,通过把定、转子接触面的摩擦损耗和转子的输出功率视为定子强迫振动的等效阻尼损失,由此建立电动机的机械特性和输出功率表达式;最后,仿真和试验分析了不同电动机结构和材料参数以及定子预压力、驱动频率和摩擦层厚度等对电动机振动特性和机械特性的影响,试验证明了该模型的有效性和适用范围。

关键词：超声波电动机解析模型能量等效机械特性振动特性