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A Novel Method for Frequency Selective Surface Design Using Deep Learning with Improved Particle Swarm Algorithm 9

A Novel Method for Frequency Selective Surface Design Using ...

9th IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, MAPE 2022

作者： Cong, Riqiu Liu, Ning Gao, Xiang Zhang, Chunbo Yang, Kaihua Sheng, Xianjun Dalian University of Technology Dalian China Lianyungang Jari Electronics Co. Ltd Lianyungang China Aerospace Institute of Advanced Material & Processing Technology Beijing China

ISBN: (数字)9781665427753

ISBN: (纸本)9781665427753

This paper presents a design method for frequency selective surface (FSS) based on the deep neural network and improved particle swarm algorithm (IPSO). In the proposed method, the forward prediction network (FPN) based on the fully connected network is established to fast predict the transmission coefficient of FSS. Combined with the FPN, the IPSO is used to optimize the structural parameters of FSS. Compared with the traditional iterative optimization method based on full-wave simulation, this method greatly improves the optimization efficiency of FSS. For example, a band-stop FSS is optimized with the proposed method in 210.6s, and the optimization efficiency increases by more than 99%. Simulation results show that the transmission coefficient errors of key frequency points between optimization results and objectives are less than 1 dB. And the deviation of the center frequency and the bandwidth of the target frequency bands is less than 0.81% and 4.1%, respectively. © 2022 IEEE.

关键词： Deep neural networks

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High-entropy spinel ferrites MFe_(2)O_(4)(M=Mg,Mn,Fe,Co,Ni,Cu,Zn)with tunable electromagnetic properties and strong microwave absorption

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Journal of advanced Ceramics 2022年第5期11卷 754-768页

作者： Jiabin MA Biao ZHAO Huimin XIANG Fu-Zhi DAI Yi LIU Rui ZHANG Yanchun ZHOU Henan Key Laboratory of Aeronautical Materials and Application Technology School of Materials Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China School of Material Science and Engineering Shaanxi University of Science and TechnologyXi'an 710021China School of Materials Science and Engineering Luoyang Institute of Science and TechnologyLuoyang 471023China

Ferrites are the most widely used microwave absorbing materials to deal with the threat of electromagnetic(EM)***,the lack of sufficient dielectric loss capacity is the main challenge that limits their *** cope with this challenge,three high-entropy(HE)spineltype ferrite ceramics including(Mg_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))Fe_(2)O_(4),(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2))Fe_(2)O_(4),and(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Zn_(0.2))Fe_(2)O_(4)were designed and successfully prepared through solid state *** results show that all three HE MFe_(2)O_(4) samples exhibit synergetic dielectric loss and magnetic *** good magnetic loss ability is due to the presence of magnetic components;while the enhanced dielectric properties are attributed to nano-domain,hopping mechanism of resonance effect and HE *** three HE spinels,(Mg_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))Fe_(2)O_(4)shows the best EM wave absorption performance,e.g.,its minimum reflection loss(RL_(min))reaches-35.10 dB at 6.78 GHz with a thickness of 3.5 mm,and the optimized effective absorption bandwidth(EAB)is 7.48 GHz from 8.48 to 15.96 GHz at the thickness of 2.4 *** to the easy preparation and strong EM dissipation ability,HE MFe_(2)O_(4) are promising as a new type of EM absorption materials.

关键词： high-entropy ceramics(HECs) spinel-type ferrite electromagnetic(EM)wave absorption dielectric loss magnetic loss

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Tunnel-structured willemite Zn_(2)SiO_(4):Electronic structure,elastic,and thermal properties

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Journal of advanced Ceramics 2022年第8期11卷 1249-1262页

作者： Ruqiao DAI Renfei CHENG Jiemin WANG Chao ZHANG Cuiyu LI Hailong WANG Xiaohui WANG Yanchun ZHOU Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Advanced Computing East China Sub-center Suma Technology Company LimitedKunshan 215300China School of Material Science and Engineering Zhengzhou UniversityZhengzhou 450001China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China

Willemite Zn_(2)SiO_(4)crystallizes in such a way that Zn and Si are tetrahedrally coordinated with O in an ionic–covalent manner to form ZnO_(4)and SiO_(4)tetrahedra as the building *** tetrahedra are corner-sharing,of which one SiO_(4)tetrahedron connects eight ZnO_(4)tetrahedra,and one ZnO_(4)tetrahedron links four ZnO_(4)tetrahedra and four SiO_(4)*** unique crystallographic configuration gives rise to parallel tunnels with a diameter of 5.7Åalong the c-axis *** tunnel structure of Zn_(2)SiO_(4)definitely correlates with its interesting elastic and thermal *** the one hand,the elastic modulus,coefficient of thermal expansion(CTE),and thermal conductivity are ***_(2)SiO_(4)has low Vickers hardness of 6.6 GPa at 10 N and low thermal conductivity of 2.34 W/(m·K)at 1073 *** the other hand,the elastic modulus and CTE along the c-axis are significantly larger than those along the a-and b-axes,showing obvious elastic and thermal expansion ***,the Young’s modulus along the z direction(Ez=179 GPa)is almost twice those in the x and y directions(Ex=Ey=93 GPa).The high thermal expansion anisotropy is ascribed to the empty tunnels along the c-axis,which are capable of more accommodating the thermal expansion along the a-and *** striking properties of Zn_(2)SiO_(4)in elastic modulus,hardness,CTE,and thermal conductivity make it much useful in various fields of ceramics,such as low thermal expansion,thermal insulation,and machining tools.

关键词： Zn_(2)SiO_(4) electronic structure elastic properties thermal expansion thermal conductivity

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Effect of densification process on mechanical enhancement of graphene laminates

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Nano materials Science 2025年第02期 240-248页

作者： Yue Zhu Yalong Liao Meng Wang Jingxin Dai Chaoshuai Lei Xiaobo Liu Pengyu Mu Wenjing Li Hao Zhang Aerospace Institute of Advanced Material & Processing Technology Academy of Deep Earth Sciences China Coal Research Institute

Graphene nanosheets have attracted great attention in the field of nanotechnology applications due to their extraordinary mechanical properties. While the structural defects such as gaps will occur during the preparation of graphene laminates, which will greatly damage the performance of the macroscopic material. Hence, a simple and promising mechanical compression method is used to improve the mechanical properties of graphene laminates. However, the roles of the densification process in the mechanical enhancement mechanism of graphene laminates are not clear. In our work, the mechanical enhancement of the compressed graphene (PG) laminates was investigated by the coarse-grained molecular dynamics simulation method. The tensile strength of PG model could be increased by increasing the graphene nanosheet size and the degree of compression in the system. And the model has the stronger van der Waals effect between graphene sheets due to the larger graphene size as well as the higher overlap ratio. Furthermore, two kinds of PG laminates were prepared by densification method, and the tensile strength was consistent with the upward trend of the PG model. This work provides an in-depth understanding on the mechanical enhancement of the densification process and lays a foundation for the future practical application of graphene laminates.

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Theoretical predictions and experimental verification on the phase stability of enthalpy-stabilized HE TMREB_(2)s

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Journal of materials Science & technology 2022年第26期121卷 154-162页

作者： Ze Zhang Shizhen Zhu Fu-Zhi Dai Huimin Xiang Yanbo Liu Ling Liu Zhuang Ma Shijiang Wu Fei Liu Kuang Sun Yanchun Zhou School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing 100076China National Key Laboratory of Science and Technology on Materials Under Shock and Impact Beijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing 314019China Zibo Firststar New Material Incorporated Co. Ltd.Zibo 255000China Shanghai Chenhua Science and Technology Corporation Ltd. Shanghai 201804China

Transition metal diborides(TMB_(2)s)are the materials of choice in extreme environments due to their excellent thermal and chemical ***,the degradation of oxidation resistance of TMB_(2)s at elevated temperature still hinders their *** cope with this challenge,it is effective to incorporate rare earth elements to form high-entropy transition and rare-earth metal diborides(HE TMREBs).To obtain thermodynamically stable single-phase structures for HE TMREB_(2)s,a“16×16 mixed enthalpy matrix”is constructed using first-principles calculations to predict the single-phase formation ability of120 two-component diborides(TCBs).Through the use of the“16×16 mixed enthalpy matrix”of TCBs,specific combinations of TMB_(2)s and REB_(2)s that are most likely to form single-phase HE TMREB_(2)s are ***,based on the energy distribution of the local mixing enthalpies of all possible configurations,the enthalpy and entropy descriptors of HE TMREB_(2)s(RE=Sc,Lu,Tm,Er,Ho and Dy)are *** is found that the mixing enthalpy plays a critical role in the stability of the single-phase HE TMREB_(2)s,i.e.,HE TMREB_(2)s are enthalpy-stabilized *** experimental results further confirm that enthalpy dominates the thermodynamic domain and drives the stability of REB_(2)s in HE TMREB_(2)*** study validates that enthalpy-stabilized HE TMREB_(2)s can further expand the compositional space of ultrahigh temperature ceramics(UHTCs)and is expected to further improve the oxidation resistance and high temperature properties of UHTCs.

关键词： High-entropy ceramics Ultrahigh temperature ceramics First-principles calculation Mixing enthalpy Transition and rare earth metal diborides

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One-step synthesis and electromagnetic absorption properties of high entropy rare earth hexaborides(HE REB6)and high entropy rare earth hexaborides/borates(HE REB6/HE REB03)composite powders

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Journal of advanced Ceramics 2021年第1期10卷 62-77页

作者： Weiming ZHANG Biao ZHAO Huimin XIANG Fu-Zhi DAI Shijiang WU Yanchun ZHOU Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China Zibo Firststar New Material Incorporated Co. Ltd.Zibo 255000China

Considering the emergence of severe electromagnetic interference problems,it is vital to develop electromagnetic(EM)wave absorbing materials with high dielectric,magnetic loss and optimized impedance ***,realizing the synergistic dielectric and magnetic losses in a single phase material is still a ***,high entropy(HE)rare earth hexaborides(REB6)powders with coupling of dielectric and magnetic losses were designed and successfully synthesized through a facial one-step boron carbide reduction method,and the effects of high entropy borates intermedia phases on the EM wave absorption properties were *** HE REB6 ceramics including(Ce0.2Y0.2Sm0.2Er0.2Yb0.2)B6,(Ce0.2Hu0.2Sm0.2Er0.2Yb0.2)B6,(Ce0.2Y0.2Eu0.2Er0.2Yb0.2)B6,(Ce0.2Ya2Sm0.2Eu0.2Yb0.2)B6,and(Nd0.2Y0.2Sm0.2Eu0.2Yb0.2)B6 possess CsCl-type cubic crystal structure,and their theoretical densities range from 4.84 to 5.25 g/cm^(3).(Ce02Y0.2Sm0.2Er0.2Yb02)B6 powders with the average particle size of 1.86 jim were found to possess the best EM wave absorption properties among these *** RLmin value of(Ce0.2Y0.2Sm0.2Er0.2Yb0.2)B6 reaches-33.4 dB at 11.5 GHz at thickness of 2 mm;meanwhile,the optimized effective absorption bandwidth(EAB)is 3.9 GHz from 13.6 to 17.5 GHz with a thickness of 1.5 *** introduction of HE REB03(RE=Ce,Y,Sm,Eu,Er,Yb)as intermediate phase will give rise to the mismatching impedance,which will further lead to the reduction of reflection ***,the HEREB6/HEREB03 still possess wide effective absorption bandwidth of 4.1 GHz with the relative low thickness of 1.7 *** the better stability,low density,and good EM wave absorption properties,HE REB6 ceramics are promising as a new type of EM wave absorbing materials.

关键词： high entropy rare earth hexaborides(HE REB6) one-step synthesis electromagnetic wave absorbing properties synergistic dielectric and magnetic losses wide effective absorption bandwidth

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Electromagnetic wave absorbing properties of TMCs(TM=Ti,Zr,Hf,Nb and Ta)and high entropy(Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C

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Journal of materials Science & technology 2021年第15期74卷 105-118页

作者： Yanchun Zhou Biao Zhao Heng Chen Huimin Xiang Fu-Zi Dai Shijiang Wu Wei Xu Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing100076China Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou450046China Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin300072China Zibo Firstar New Material Incoqjorated Co.Ltd. Zibo255000China Shanghai Chenhua Science and Technology Coloration Ltd. Shanghai201804China

Electromagnetic wave(EMW)absorbing materials play a vital role in modern communication and information processing technologies to inhibit information leakage and prevent possible damages to environment and human ***,most of EMW absorbing materials are either composites of two or more phases or in the form of nanosheets,nanowires or nanofibers in order to enhance the EMW absorption performance through dielectric loss,magnetic loss and dielectric/magnetic loss ***,the combination of complex shapes/multi phases and nanosizes may compound the difficulties of materials processing,composition and interfaces control as well as performance maintenance during ***,searching for single phase materials with good stability and superior EMW absorbing properties is *** achieve this goal,the EMW absorbing properties of transition metal carbides TMCs(TM=Ti,Zr,Hf,Nb and Ta)and high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C which belong to ultrahigh temperature ceramics,were investigated in this *** to the good electrical conductivity and splitting of d orbitals into lower energy t2glevel and higher energy eglevel in TMC6octahedral arrangement,TMCs(TM=Ti,Zr,Hf,Nb and Ta)exhibit good EMW absorbing ***,Hf C and Ta C exhibit superior EMW absorbing *** minimum reflection loss(RLmin)value of Hf C is-55.8 d B at 6.0 GHz with the thickness of 3.8 mm and the effective absorption bandwidth(E_(AB))is 6.0 GHz from 12.0 to 18.0 GHz at thickness of 1.9 mm;the RL_(minvalue)of Ta C reaches-41.1 d B at 16.2 GHz with a thickness of 2.0 mm and the EABis 6.1 GHz with a thickness of 2.2 ***,the electromagnetic parameters,i.e.,complex permittivity and permeability are tunable by forming single phase solid solution or high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))*** R_(Lminvalue)of high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C is-38.5 d B at 9.5 GHz with the thickness of 1.9 mm,and the EA

关键词： Transition metal carbides High entropy ceramics Microwave absorption Electromagnetic parameters Electronic structure Crystal field theory

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Characterization of plasma rotating electrode atomized Nb-Ti based alloy powder

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Metal Powder Report 2020年第2期75卷 82-91页

作者： Li, Qijun Zhang, Lin Chen, Xiaowei Wei, Dongbin Zhang, Peng Chen, Yan Qu, Xuanhui Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and Technology University of Science and Technology Beijing100083 China Aerospace Research Institute of Material and Processing Technology Beijing100076 China

Nb-Ti based alloy powder was prepared by plasma rotating electrode process. The relationship between microstructure, particle size and cooling rate was investigated. Phase constituents and surface state of the powder were characterized. The results indicated that particle size of the Nb-Ti based alloy powder ranged from 30 to 165 μm. Most of the atomized Nb-Ti based alloy powder particles had a smooth surface and near-perfect spherical shape. The atomized powder was found to be single β phase with dendritic, cellular or microcrystalline structure. The reduction in powder size and the increase in cooling rate had transformed the solidification morphologies of the PREP powder from dendrite in major to a cellular structure. The secondary dendritic spacing was measured to be 1.32 ∼ 2.71 μm, and the corresponding cooling rates were estimated to be in the range of 4.50 × 104 ∼ 3.75 × 105 K·s−1. Oxygen contamination on the surface of the powder existed in the form of Nb2O5 and TiO2, and the thickness of the oxide layer was about 8 nm. © 2019 Elsevier Ltd

关键词： Particle size

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(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Mo_(0.2))B:A novel high-entropy monoboride with good electromagnetic interference shielding performance in K-band

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Journal of materials Science & technology 2021年第18期77卷 58-65页

作者： Haiming Zhang Biao Zhao Fu-Zhi Dai Huimin Xiang Zhili Zhang Yanchun Zhou Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyNo.1 South Dahongmen RoadBeijing100076China School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing100044China Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou450046China

A novel equimolar high-entropy(HE)transition metal monoboride,(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Mo_(0.2))B,was designed and prepared in powder and bulk form by high temperature elemental reaction method and spark plasma sintering(SPS)method,*** analysis shows that HE(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Mo_(0.2))B possesses orthorhombic structure with Pnma space *** Rietveld refinement,the lattice parameters of HE(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Mo_(0.2))B are a=5.6675,b=2.9714,c=4.2209 and the theoretical density is 6.95 g/cm~*** Vickers hardness and electrical conductivity of HE(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Mo_(0.2))B bulk with relative density of 90%is 12.3±0.5 GPa and 0.49±0.04×10~6 S/m,*** to high electrical conductivity,HE(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Mo_(0.2))B bulk with 3.0 mm thickness displays superior EMI shielding performance in 18.0–26.5 GHz(K-band),and the average values of SET,SER,and SEAare 23.3 dB,13.9 dB,and 9.4 dB,*** EMI shielding mechanism of HE(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Mo_(0.2))B mainly results from reflection.

关键词： High-entropy ceramics Transition metal monoboride Electromagnetic interference(EMI)shielding Mechanical properties Electrical conductive ceramics

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Long-term oxidation resistance of a Ti65 alloy with Cr 2 AlC coating by magnetron sputtering

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Corrosion Communications 2025年 18卷 66-75页

作者： Ke Ma Yang Li Jingjing Li Jinming Wang Jingjun Xu Jun Zuo Meishuan Li Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China School of Materials Science and Engineering University of Science and Technology of China Hefei 230026 China School of Materials Science and Engineering Shenyang Ligong University Shenyang 110159 China Science and Technology on Advanced Functional Composites Laboratory Aerospace Research Institute of Material and Processing Technology Beijing 100076 China

In this study, novel high-quality Cr 2 AlC coating was fabricated on Ti65 alloy substrate as its protective oxidation resistance coating. Isothermal oxidation tests were performed at 650 and 750 °C for up to 400 h in air. The results indicated that Ti65 alloy underwent severe oxidation at 750 °C, accompanied by the presence of the cracking and exfoliating of the oxide scale during oxidation. Compared to the bare Ti65 substrate, the coated samples revealed more excellent oxidation resistance, meeting the parabolic law with low oxidation rate constants of 8.70×10 −13 kg 2 ·m −4 ·s −1 at 650 °C and 2.80×10 −13 kg 2 ·m −4 ·s −1 at 750 °C. At the surface, Al preferentially oxidized to form the protective Al 2 O 3 layer and synchronously Cr 7 C 3 sublayer, retarding the inward diffusion of oxygen and presenting excellent oxidation resistance. Besides, at the coating/substrate interface, Al diffused from Cr 2 AlC coating into the substrate to form an Al-rich layer in substrate adjacent to the coating/substrate interface. Due to the Al consumption, Cr-carbide and nitride, as well as TiN, were thereby formed at the interface reaction layer, which could act as a barrier for the interdiffusion process.

关键词： Ti65 titanium alloy Cr 2 AlC coating Oxidation behaviors Interface reaction Oxidation mechanism

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