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A radar-infrared compatible broadband absorbing surface:Design and analysis

Chinese Physics B 2021年第7期30卷 605-612页

作者： Qing-Tao Yu Yuan-Song Zeng Guo-Jia Ma Aviation Key Laboratory of Science and Technology on Advanced Surface Engineering AVIC Manufacturing Technology InstituteBeijing 100024China

A radar-infrared compatible stealth surface is designed and *** modifying the radar absorbing material(RAM),the design can theoretically achieve radar-infrared compatibility and broadband radar absorption through surface patterns and structures.A transmission-line-based model(TLM)is developed to analyze the radar absorbing performance of the *** of the structure geometries is conducted aiming to maximize the-10 d B absorption bandwidth in 2–18 *** with optimized structure geometries exhibits a superior absorption bandwidth,more than twice the bandwidth of the original 1.5 mm RAM slab,while maintaining a relatively low infrared emissivity.

关键词： stealth infrared-radar compatible broadband absorbing patterned surface

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The dielectric behavior and efficient microwave absorption of doped nanoscale LaMnO_(3)at elevated temperature

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Nano Research 2022年第8期15卷 7731-7741页

作者： Zhigang Mu Guoke Wei Hang Zhang Lu Gao Yue Zhao Shaolong Tang Guangbin Ji College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aviation Key Laboratory of Science and Technology on Advanced Surface Engineering AVIC Manufacturing Technology InstituteBeijing 100024China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China

LaMnO_(3)perovskite has great potential in microwave absorption at high temperature due to its complex doping effect and super *** current research mainly focuses on the doping ratio regulation,while the mechanism of doping effect at high temperature is still lack of sufficient *** this work,La1−xSrxMn1−yFeyO_(3)(LaMnO_(3),La_(0.7)Sr_(0.3)MnO_(3),and La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3))nanostructures with different doping sites were successfully prepared by the solid phase reaction ***,the high temperature dielectric test samples were obtained by mixing with cordierite(2MgO·2Al_(2)O_(3)·5SiO_(2)(MAS)).The results showed that the temperature dependence of Mn ion spin state had a significant impact on the high temperature dielectric behavior of La_(1−x)Sr_(x)Mn_(1−y)FeyO_(3).Particularly,when the thickness is only 1.9 mm,La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)/MAS can achieve the widest bandwidth of 4.2 GHz covered the entire X-band(8.2–12.4 GHz)and a minimum reflection loss(RL)value of−17.99 dB at 500℃.In order to improve the operating temperature of La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)/MAS,a cellular array structure was designed by using computer simulation technology(CST)software to introduce magnetic *** the outer length of the hexagon is 1 mm and the coating thickness is 1.9 mm,the widest bandwidth covers the X-band and the minimum RL value is−15.35 dB at 800℃.Therefore,La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)has a great prospect as an efficient high temperature microwave absorber.

关键词： microwave absorption doping perovskite high temperature dielectric behavior

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Prediction of New Functional Fluorooxoborates with Expected Anionic Framework:A Case of CaB_(3)O_(5)F

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Chinese Physics Letters 2025年第3期42卷 85-92页

作者： Ke-Wang Zhang Wen-Qi Jin Ke Li Abudukadi Tudi Lin-Lin Liu Cong-Wei Xie Yu Xie Research Center for Crystal Materials CAS Key Laboratory of Functional Materials and Devices for Special Environmental ConditionsXinjiang Key Laboratory of Functional Crystal MaterialsXinjiang Technical Institute of Physics&ChemistryCASUrumqi 830011China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Materials Simulation Methods&Software of Ministry of Education International Center of Future ScienceKey Laboratory of Physics and Technology for Advanced Batteries(Ministry of Education)College of PhysicsJilin UniversityChangchun 130012China

The prediction of new fluorooxoborates as ultraviolet(UV)/deep ultraviolet(DUV)opto-electronic functional materials from a largely unexplored chemical space is a challenging *** has been suggested that the anionic frameworks formed by B–O and B–O–F units significantly determine the physical properties of ***,the rational design of anionic frameworks could facilitate the materials discovery ***,we propose that a candidate anionic framework can be efficiently derived from an existing one by slightly altering its oxygen *** this idea,we hypothesized the existence of a 1D[B_(3)O_(5)F]_(∞)chain from the wellknown 2D[B_(6)O_(9)F_(2_)]_(∞)***,seven CaB_(3)O_(5)F structures with the expected anionic framework were successfully ***-principles calculations show that all these structures have potential in the UV/DUV birefringent or nonlinear optical(NLO)material field,indicating that the 1D[B_(3)O_(5)F]_(∞)chain is indeed a promising anionic framework for achieving UV/DUV birefringent and NLO performance.

关键词： process borate anionic

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Underestimated benefits of NO_(x) control in reducing SNA and O_(3) based on missing heterogeneous HONO sources

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Frontiers of Environmental science & Engineering 2024年第3期18卷 57-67页

作者： Shuping Zhang Haotian Zheng Jun Liu Yao Shi Tianzeng Chen Chaoyang Xue Fenfen Zhang Yueqi Jiang Xiangping Zhang Shovan Kumar Sahu Biwu Chu Jia Xing State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China China Academy of Civil Aviation Science and Technology Beijing 100028China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Yellow River Institute of Hydraulic Research Zhengzhou 450003China Centre for Climate Research Singapore Meteorological Service SingaporeSingapore 537054Singapore

Substantial NO_(x) emission mitigation is crucial for the synergistic reduction of particulate matter and ozone(O_(3))pollution in *** traditional air quality model does not consider heterogeneous HONO chemistry,leading to uncertainties in estimating the benefits of NO_(x) *** studies have shown that the parameterization of heterogeneous HONO formation increases both the simulated value of sulfate–nitrate–ammonium(SNA)and that of O_(3),thus adding the heterogeneous reactions of HONO into air quality models inevitably leads to changes in the estimated benefits of NO_(x) *** we investigated the changes in SNA and O_(3)concentrations from NO_(x) emission reduction before and after adding heterogeneous HONO reactions in the Community Multi-Scale Air Quality(CMAQ)*** heterogeneous HONO reactions in the simulation improved the benefits of NO_(x) reduction in terms of SNA control in *** 80%NO_(x) reduction,the reduction in SNA increased from 36.9%without considering heterogeneous HONO reactions to 42.8%with heterogeneous HONO *** reduction in the maximum daily 8h average(MDA8)O_(3)in summer caused by NO_(x) reduction increased slightly from 4.7%to 5.2%after adding heterogeneous HONO *** results in this study highlight the enhanced effectiveness of NO_(x) controls for the reduction of SNA and O_(3)after considering heterogeneous HONO formation in a complex chemical ambient,demonstrating the importance of NO_(x) controls in reducing PM2.5 and O_(3)pollution in China.

关键词： Heterogeneous HONO NO_(x) reduction PM_(2.5) O_(3)

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Rare earth element Ce enables high thermoelectric performance in n-type SnSe polycrystals

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Journal of Materials science & technology 2023年第12期143卷 234-241页

作者： Shan Li Li Yin Yijie Liu Xiaodong Wang Chen Chen Qian Zhang School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710072China School of Materials Science and Engineering and Institute of Materials Genome&Big DataHarbin Institute of TechnologyShenzhen 518055China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

SnSe exhibits excellent thermoelectric performance in both n-and p-type single crystals,but its n-type polycrystals are restricted because of the lower electrical ***,we dually introduced rare earth element Ce and PbTe to optimize the thermoelectric properties of n-type SnSe *** is demonstrated that Ce is an effective cationic dopant to convert SnSe from p-to n-type conductor,and an enhanced peak zT value of∼0.9 at 823 K was obtained in Sn 0.97 Ce 0.03 Se due to the improved power ***,PbTe alloying not only reduced the band gap to increase the carrier concentration,but also enhanced the density-of-states effective mass,and hence further increased the power factor in the whole measured temperature ***,the lattice thermal conductivity was significantly reduced owing to the enhanced phonon scattering by the mass and strain *** a result,the peak zT value was increased to∼1.3 for Sn 0.9 Pb 0.07 Ce 0.03 Se 0.93 Te 0.07 together with a high average zT value of∼0.52 in the temperature range of 300 to 823 K.

关键词： Thermoelectric N-type SnSe Ce doping PbTe alloying

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Sign reversal and manipulation of anomalous Hall resistivity in facing-target sputtered Pt/Mn_(4)N bilayers

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Rare Metals 2023年第2期42卷 591-601页

作者： Ze-Yu Zhang Jia-Wei Jiang Xiao-Hui Shi Xiang Liu Xia Chen Zhi-Peng Hou Wen-Bo Mi Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology School of ScienceTianjin UniversityTianjin300354China School of Physics and Electronic Engineering Linyi UniversityLinyi276000China College of Science Civil Aviation University of ChinaTianjin300300China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology&Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China

The magnetic and electronic transport properties manipulated by spin-orbit torque have been devoted much attention as they show a great promise for future spintronic ***,the spin dependent transport properties of the facing-target sputtered Pt/Mn_(4)N bilayers on MgO(001)substrates have been investigated *** Hall resistivity of Pt/Mn_(4)N bilayers is strongly dependent on temperature,applied current intensity,Mn_(4)N and Pt layer *** temperature-dependent sign reversal of anomalous Hall resistivity appears in Pt/Mn_(4)N bilayers,which is dominated by the competition between the magnetic proximity and spin Hall ***,the magnitude of anomalous Hall resistivity can be manipulated by applied current *** critical and saturation currents are related to Mn_(4)N and Pt layer ***,a Dzyaloshinskii-Moriya interaction coefficient(D)of 5.63 mJ·m^(-2)is calculated in Pt/Mn_(4)N/MgO *** details of the anomalous Hall effects in Pt/Mn_(4)N bilayers are helpful to understand the interfacial effects between heavy metals and ferrimagnets.

关键词： Pt/Mn_(4)N bilayer Hall resistivity Magnetic proximity effect Spin Hall effect(SHE) DzyaloshinskiiMoriya interaction(DMI)

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A Grey Wolf Optimizer Variant with Weighted-leader Strategy 24

A Grey Wolf Optimizer Variant with Weighted-leader Strategy

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3rd International Conference on Signal Processing, Computer Networks and Communications, SPCNC 2024

作者： Liang, Yajun Yan, Su Ma, Qian Huang, Shunlun Liu, Xin China Aerodynamics Research & Development Center Sichuan Mianyang China Science and Technology on Complex Aviation Systems Simulation Laboratory Beijing China State Key Laboratory of Air Traffic Management System Beijing China Beijing Aviation Meteorological Institute Beijing China

ISBN: (纸本)9798400710834

To enhance the convergence capability of grey wolf optimizer (GWO), this research investigates an evolved GWO using weighted-leader strategy (WLS), namely WLSGWO. The key issue of WLS is realizing the adaptive adjustment of position weighting according to the control parameters, thus well overcoming the drawback of premature convergence in the basic GWO. The newly developed method’s performance is assessed through experiments conducted on a standardized test suite. Additionally, comparisons are made by utilizing GWO alongside other advanced optimization techniques. The results of non-parametric studies validate the outperformance of the WLSGWO, thus proving the efficiency of the proposed strategy. © 2024 Copyright held by the owner/author(s).

关键词： Swarm intelligence

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Outer delocalized electron aggregation of bromide bridged core–shell CuBr@C for hydrogen evolution reaction

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Nano Research 2023年第5期16卷 6608-6614页

作者： Tianyi Xu Ruoyu Li Lei Zhang Dongxu Jiao Yilong Dong Ming Gong Dantong Zhang Jinchang Fan Dewen Wang Yanhua Liu Xiao Zhao Wei Zhang Weitao Zheng Xiaoqiang Cui State Key Laboratory of Automotive Simulation and Control School of Materials Science and EngineeringKey Laboratory of Automobile Materials of MOEJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsElectron Microscopy CenterJilin UniversityChangchun 130012China College of Chemistry Jilin UniversityChangchun 130012China Center of Multiscale Crystal Materials Research Institute of Advanced Materials Science and EngineeringShenzhen Intitute of Advanced TechnologyChinese Academy of ScienceShenzhen 518055China

Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic ***,we address this challenge by bridging the inner and outer layers of the core–shell structure through the bridge Br *** shell wrapped copper bromide nanorods(CuBr@C)are constructed for the first time by chemical vapour deposition with hexabromobenzene(HBB).HBB pyrolysis provides both bridge Br atom and C *** C shell protects the stability of the internal halide structure,while the bridge Br atom triggers the rearrangement of the surface electrons and exhibits excellent electrocatalytic ***,the hydrogen evolution reaction(HER)activity of CuBr@C is significantly better than that of commercial N-doped carbon nanotubes,surpassing commercial Pt/C at over 200 mA·cm^(−2).Density functional theory(DFT)calculations reveal that bridge Br atoms inspire aggregation of delocalized electrons on C-shell surfaces,leading to optimization of hydrogen adsorption energy.

关键词： bridge Br atoms delocalized electron aggregation core–shell nanorods C-shell wrapped CuBr hydrogen evolution reaction

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Influence of Alloying Elements Content on High Temperature Properties of Ti-V-Cr and Ti-Al-V Series Titanium Alloys: A JMatPro Program Calculation Study

Influence of Alloying Elements Content on High Temperature P...

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Chinese Materials Conference 2022-2023

作者： Sun, Ruochen Mi, Guangbao Aviation Key Laboratory of Science and Technology on Advanced Titanium Alloys AECC Beijing Institute of Aeronautical Materials Beijing100095 China

For the issues of high temperature performance affected by the alloying elements content in Ti-V-Cr and Ti-V-Cr alloys, the thermodynamic calculation method based on JMatPro program was applied in this study. The research is mainly focused on the analysis of phase composition, thermodynamic parameters and mechanical properties of Ti-Al-V and Ti-V-Cr series alloys with different element proportions under high temperature environment. Those obtained results show that the proportion of Al in Ti-Al-V alloys has a great influence on the high temperature properties. Increasing the content of Al not only increases the transformation temperature of β single-phase structure and delays the transformation process of α/β microstructure to β single-phase structure, but also helps to improve the high temperature thermal conductivity and elastic deformation resistance of the alloy. In Ti-V-Cr alloys, the influence of V element on high temperature properties is mainly focused on the improvement of thermal conductivity and high temperature deformation properties, while the influence of Cr element is relatively weak. Besides, adding a small amount of Al element to Ti-V-Cr alloy can further improve the thermal conductivity of the alloy. The Young's modulus of the Ti-V-Cr alloy increases when 0.3%-1% of C element is added. Finally, the effect of Si element on the high temperature elastic deformation of the alloy is relatively weak. © Published under licence by IOP Publishing Ltd.

关键词： Titanium alloys

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Rubik’s cube as in-situ programmable matter and a reconfigurable mechanical metamaterial

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science China(Technological sciences) 2024年第10期67卷 3221-3234页

作者： ZHU ShaoWei CHEN Huan YANG XiaoQiang TAN Li JIN Shuai CHEN LiMing LIU Tao TAN XiaoJun WANG LianChao WANG Bing MUAMER Kadic State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China College of Aerospace Engineering Chongqing UniversityChongqing 400030China School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710129China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Institut FEMTO-ST CNRS UMR 6174University BourgogneFranche-ComtBesan¸con 25000France

As part of the 4th industrial revolution,programmable mechanical metamaterials exhibit great application potential in flexible robotics,vibration control,and impact ***,maintaining a programmed state without sustaining the external stimulus is often challenging and leads to additional energy *** by Rubik’s cube,we design and study an in-situ programmable and distribution-reconfigurable mechanical metamaterial(IPDR-MM).A matrix model is developed to model IPDR-MMs and describe their morphological *** on this model,the reinforcement learning method is employed to find the pathways for morphological *** find that IPDR-MMs have controllable stiffness across several orders of magnitude and a wide range of adjustable anisotropies through morphology ***,because of the independence of the directions of morphology transformation and bearing,IPDR-MMs exhibit good stability in bearing and can readily achieve high *** Rubik’s cube-inspired design concept is also instructive for other deformable structures and metamaterials,and the current version of the proposal should be sufficiently illustrative to attract and broaden interdisciplinary interests.

关键词： mechanical metamaterials in-situ programmable distribution-reconfigurable Rubik’s cube controllable stiffness and anisotropy

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