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magnetic-coupling Based Waveguide-to-Microstrip Transition

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Journal of Electronic Science and Technology 2011年第2期9卷 185-189页

作者： Jun Xu Zhi-Tao Xu Mao-Yan Wang Chun-Rong Zheng Yi Wang Li-Hui Jiang School of Physical Electronics University of Electronic Science and Technology of ChinaChengdu 610054China

A novel millimeter-wave waveguide-to-microstrip transition based on magnetic-coupling is presented in this paper.The mode conversion of electromagnetic field is realized with the ring strip line of arbitrary shape in the E-plane of rectangular waveguide and the eccentric quasi-coaxial line,which is partially filled with media and consists of outer and inner rectangular conductors.The structure has the advantages of low loss,wide bandwidth,compact structure,and avoiding debug.From 27 GHz to 40 GHz,the experiment results show that the insertion loss is less than 1.2 dB and the return loss is better than 13.5 dB for the back-to-back transition with semicircle ring strip lines.

关键词： magnetic coupling mircostrip line transition rectangular waveguide

Modeling and dynamics of double Hindmarsh-Rose neuron with memristor-based magnetic coupling and time delay

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Chinese Physics B 2021年第12期30卷 102-110页

作者：齐国元王子谋 Tianjin Key Laboratory of Intelligent Control of Electrical Equimpment Tiangong UniversityTianjin 300387China

The firing of a neuron model is mainly affected by the following factors:the magnetic field,external forcing current,time delay,etc.In this paper,a new time-delayed electromagnetic field coupled dual Hindmarsh-Rose neuron network model is constructed.A magnetically controlled threshold memristor is improved to represent the self-connected and the coupled magnetic fields triggered by the dynamic change of neuronal membrane potential for the adjacent neurons.Numerical simulation confirms that the coupled magnetic field can activate resting neurons to generate rich firing patterns,such as spiking firings,bursting firings,and chaotic firings,and enable neurons to generate larger firing amplitudes.The study also found that the strength of magnetic coupling in the neural network also affects the number of peaks in the discharge of bursting firing.Based on the existing medical treatment background of mental illness,the effects of time lag in the coupling process against neuron firing are studied.The results confirm that the neurons can respond well to external stimuli and coupled magnetic field with appropriate time delay,and keep periodic firing under a wide range of external forcing current.

关键词： bi-Hindmarsh and Rose(HR)neuron model memristor magnetic coupling time delay

Macroscopic Electromagnetic Cooperative Network‑Enhanced MXene/Ni Chains Aerogel‑Based Microwave Absorber with Ultra‑Low Matching Thickness

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Nano-Micro Letters 2022年第8期14卷 283-299页

作者： Fei Pan Yanping Rao Dan Batalu Lei Cai Yanyan Dong Xiaojie Zhu Yuyang Shi Zhong Shi Yaowen Liu Wei Lu Shanghai Key Lab.of D&A for Metal‑Functional Materials School of Materials Science&EngineeringTongji UniversityShanghai 201804People’s Republic of China Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology School of Physics Science and EngineeringTongji UniversityShanghai 201804People’s Republic of China Materials Science and Engineering Faculty Politehnica University of Bucharest060042 BucharestRomania

Electromagnetic cooperative strategy has been presented as a mainstream approach that can effectively optimize the matching thickness of dielectric loss dominant system.However,it is still challenging for dielectric–magnetic loss coexisting-type absorber to develop electromagnetic wave(EMW)performance with ultra-low matching thickness(≤1 mm).Breaking the limitation of traditional electromagnetic response at microscopic/mesoscopic scale,a ficus microcarpa-like magnetic aerogel with macroscopical electromagnetic cooperative effect was fabricated through highly oriented self-assembly engineering.The highly oriented Ni chains with unique macroscopic morphology(~1 cm in length)were achieved via a special magnetic field-induced growth.Strong magnetic coupling was observed in the Ni chains confirmed by the micromagnetic simulation.The deductive calculation validates that maintaining high value of electromagnetic parameters at high frequencies is the prerequisites of ultrathin absorber.The electromagnetic cooperative networks with uninterrupted and dual pathways spread through the entire aerogel skeleton,resulting in the impressive permittivity even at high frequencies.Consequently,the aerogel exhibits a remarkable EMW performance at an ultrathin thickness of 1 mm.Thus,based on the modulation of electromagnetic parameters,this work proposed a macroscopic ordered structure with the electromagnetic cooperative effect useful to develop a suitable strategy for achieving ultrathin EMW absorbers.

关键词： Electromagnetic wave absorption Ti_(3)CNT_(x)MXene Highly oriented Ni chains Electromagnetic cooperation magnetic coupling

Growth of magnetic metals on carbon microspheres with synergetic dissipation abilities to broaden microwave absorption

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Journal of Materials Science & Technology 2022年第12期107卷 100-110页

作者： Biao Zhao Yang Li Qingwen Zeng Bingbing Fan Lei Wang Rui Zhang Renchao Che Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsFudan UniversityShanghai 200438China Department of Materials Science Fudan UniversityShanghai 200438China Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhouHenan 450046China School of Material Science and Engineering Zhengzhou UniversityZhengzhouHenan 450001China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Microwave absorption(MA) materials have been captured extensive attentions due to the serious electromagnetic(EM) pollution. Numerous interests focus on the MA performances of core-shell structural composites with magnetic constituents as cores and dielectric constituents as shells, which inevitably suppressed the magnetic coupling causing the decrease of magnetic loss to some extent. Herein, the coreshell structural carbon(C) microsphere/magnetic metal composites were fabricated through the combination of an electrostatic assembly approach and subsequent in-situ reduction reaction. The complex permittivity and permeability of core-shell C@magnetic metal composite system can be effective adjusted by the constituent and microstructure of shells. Thanks to the distinct magnetic coupling from the subtle designed structures and the promotion of the magnetic-dielectric synergy, the C@magnetic metal composite exhibited enhanced MA properties. The optimal reflection loss(RL) of C@Ni composite was-54.1 dB with a thickness of 3.4 mm, meanwhile the effective absorbing band could reach over 5.5 GHz at only a1.8 mm thickness. Broad absorption bandwidth with RL below-10 d B could achieve 6.0 GHz and 6.7 GHz for C@Co and C@Ni Co composites with a thin 2.1 mm thickness, respectively. Our exciting findings might lead a guide on the novel structure design for the functional core-shell structural composites used for microwave absorption.

关键词： Microwave absorption Core-shell structure C@magnetic metal composite Interfacial polarization magnetic coupling

Hierarchical design of FeCo-based microchains for enhanced microwave absorption in C band

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Nano Research 2023年第1期16卷 1773-1778页

作者： Yixuan Han Mukun He Jinwen Hu Panbo Liu Zhongwu Liu Zhonglei Ma Wenbo Ju Junwei Gu Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China School of Physics and Optoelectronics and School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510640China

Microwave absorbing materials(MAMs)has been intensively investigated in order to meet the requirement of electromagnetic radiation control,especially in S and C band.In this work,FeCo-based magnetic MAMs are hydrothermally synthesized via a magnetic-field-induced process.The composition and morphology of the MAMs are capable of being adjusted simultaneously by the atomic ratio of Fe2+to Co2+in the precursor.The hierarchical magnetic microchain,which has a core–shell structure of twodimensional FexCo1−xOOH nanosheets anchored vertically on the surface of a one-dimensional(1D)Co microchain,shows significantly enhanced microwave absorption in C band,resulting in a reflection loss(RL)of lower than−20 dB at frequencies ranging from 4.4 to 8.0 GHz under a suitable matching thickness.The magnetic coupling of Co microcrystals and the double-loss mechanisms out of the core-shell structure are considered to promote the microwave attenuation capability.The hierarchical design of 1D magnetic MAMs provides a feasible strategy to solve the electromagnetic pollution in C band.

关键词： one-dimensional micromagnets hierarchical structure microwave absorbing material magnetic coupling double-loss mechanisms

Manipulating coupling state and magnetism of Mn-doped ZnO nanocrystals by changing the coordination environment of Mn via hydrogen annealing

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Chinese Physics B 2016年第1期25卷 762-769页

作者：程岩李文献郝维昌许怀哲徐忠菲郑离荣张静窦士学王天民 Department of Physics and Center of Materials Physics and Chemistry Beihang UniversityBeijing 100191China Solar Energy Technologies School of ComputingEngineering and MathematicsUniversity of Western SydneyPenrithNSW 2751Australia Institute for Superconducting and Electronic Materials(ISEM) University of WollongongWollongongNSW 2522Australia Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

Mn-doped ZnO nanocrystals are synthesized by a wet chemical route and treated in H2/Ar atmosphere with different H2/Ar ratios. It is found that hydrogen annealing could change the coordination environment of Mn in ZnO lattice and manipulate the magnetic properties of Mn-doped ZnO. Mn ions initially enter into interstitial sites and a Mn3＋ 06 octahedral coordination is produced in the prepared Mn-doped ZnO sample, in which the nearest neighbor Mn3＋ and 02 ions could form a Mn3＋-O2--Mn3＋ complex. After H2 annealing, interstitial Mn ions can substitute for Zn to generate the Mn2＋O4 tetrahedral coordination in the nanocrystals, in which neighboring Mn2＋ ions and H atoms could form a Mn2＋-O2--Mn2＋ complex and Mn-H-Mn bridge structure. The magnetic measurement of the as-prepared sample shows room temperature paramagnetic behavior due to the Mn3＋-O2--Mn3＋ complex, while the annealed samples exhibit their ferromagnetism, which originates from the Mn-H-Mn bridge structure and the Mn-Mn exchange interaction in the Mn2＋-O2--Mn2＋ complex.

关键词： coordination environment magnetic coupling x-ray absorption fine structure

DFT-BS study on the magnetic coupling of superhalogen systems

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DFT-BS study on the magnetic coupling of superhalogen system...

MOF-Derived Ni1-xCox@Carbon with Tunable Nano-Microstructure as Lightweight and Highly Efficient Electromagnetic Wave Absorber

第六届全国物理无机化学会议

作者： Bing Yin~*,Zhen-Yi Wen Shaanxi Key Laboratory of Physico-InorganicChemistry,MOE Key Laboratory of Synthetic and Natural Functional Molecule Chemistry,College of Chemistry & Materials Science,North-west University,Xi’an,710069.

Superhalogen species are kinds of molecular clusters consisting of highly electronegative ligands and central atoms .The most important characteristics of superhalogens is the extremely high electron affinities(EA) wh... 详细信息

关键词： superhalogen transition metal DFT-BS magnetic coupling

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Nano-Micro Letters 2020年第11期12卷 90-106页

作者： Lei Wang Mengqiu Huang Xuefeng Yu Wenbin You Jie Zhang Xianhu Liu Min Wang Renchao Che Laboratory of Advanced Materials Department of Materials Science and Collaborative Innovation Center of Chemistry for Energy Materials(iChem)Fudan UniversityShanghai 200438People’s Republic of China Key Laboratory of Materials Processing and Mold(Zhengzhou University) Ministry of EducationZhengzhou 450002People’s Republic of China

Intrinsic electric-magnetic property and special nano-micro architecture of functional materials have a significant effect on its electromagnetic wave energy conversion,especially in the microwave absorption(MA) field.Herein,porous Ni1-xCox@Carbon composites derived from metal-organic framework(MOF)were successfully synthesized via solvothermal reaction and subsequent annealing treatments.Benefiting from the coordination,carbonized bimetallic Ni-Co-MOF maintained its initial skeleton and transformed into magnetic-carbon composites with tunable nano-micro structure.During the thermal decomposition,generated magnetic particles/clusters acted as a catalyst to promote the carbon sp^2 arrangement,forming special core-shell architecture.Therefore,pure Ni@C microspheres displayed strong MA behaviors than other Ni1-xCox@Carbon composites.Surprisingly,magnetic-dielectric Ni@C composites possessed the strongest reflection loss value-59.5 dB and the effective absorption frequency covered as wide as 4.7 GHz.Meanwhile,the MA capacity also can be boosted by adjusting the absorber content from 25% to 40%.magnetic-dielectric synergy effect of MOF-derived Ni1-xCox@Carbon microspheres was confirmed by the off-axis electron holography technology making a thorough inquiry in the MA mechanism.

关键词： Metal-organic frameworks Polarization magnetic coupling Microwave absorption Electromagnetic parameters

magnetic interactions in a proposed diluted magnetic semiconductor(Ba_(1-x)K_x)(Zn_(1-y)Mn_y)_2P_2

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Chinese Physics B 2018年第6期27卷 369-375页

作者：杨焕成刘凯卢仲毅 Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices Renmin University of China

By using first-principles electronic structure calculations, we have studied the magnetic interactions in a proposed BaZn2P2-based diluted magnetic semiconductor（DMS）. For a typical compound Ba（Zn（0.944）Mn（0.056））2P2 with only spin doping, due to the superexchange interaction between Mn atoms and the lack of itinerant carriers, the short-range antiferromagnetic coupling dominates. Partially substituting K atoms for Ba atoms, which introduces itinerant hole carriers into the p orbitals of P atoms so as to link distant Mn moments with the spin-polarized hole carriers via the p–d hybridization between P and Mn atoms, is very crucial for the appearance of ferromagnetism in the compound. Furthermore, applying hydrostatic pressure first enhances and then decreases the ferromagnetic coupling in（Ba0.75 K0.25）（Zn（0.944）Mn（0.056））2P2 at a turning point around 15 GPa, which results from the combined effects of the pressure-induced variations of electron delocalization and p–d hybridization. Compared with the BaZn2 As2-based DMS, the substitution of P for As can modulate the magnetic coupling effectively. Both the results for BaZn2 P2-based and BaZn2As2-based DMSs demonstrate that the robust antiferromagnetic（AFM） coupling between the nearest Mn–Mn pairs bridged by anions is harmful to improving the performance of these Ⅱ–Ⅱ–Ⅴ based DMS materials.

关键词： magnetic semiconductor p-d hybridization magnetic coupling first-principles calculations