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Integration of Electrical Properties and Polarization Loss Modulation on Atomic Fe–N‑RGO for Boosting Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第2期17卷 517-532页

作者： Kaili Zhang Yuefeng Yan Zhen Wang Guansheng Ma Dechang Jia Xiaoxiao Huang Yu Zhou State Key Laboratory of Precision Welding&Joining of Materials and Structures Harbin Institute of TechnologyHarbin 150001People’s Republic of China School of Materials science and Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China MIIT Key Laboratory of Advanced Structural‑Functional Integration Materials&Green Manufacturing technology Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Developing effective strategies to regulate graphene’s conduction loss and polarization has become a key to expanding its application in the electromagnetic wave absorption(EMWA)*** on the unique energy band structure of graphene,regulating its bandgap and electrical properties by introducing heteroatoms is considered a feasible ***,metal-nitrogen doping reduced graphene oxide(M–N-RGO)was prepared by embedding a series of single metal atoms M–N_(4) sites(M=Mn,Fe,Co,Ni,Cu,Zn,Nb,Cd,and Sn)in RGO using an N-coordination atom-assisted *** composites had adjustable conductivity and polarization to optimize dielectric loss and impedance matching for efficient EMWA *** results showed that the minimum reflection loss(RL_(min))of Fe–N-RGO reaches−74.05 dB(2.0 mm)and the maximum effective absorption bandwidth(EAB_(max))is 7.05 GHz(1.89 mm)even with a low filler loading of only 1 wt%.Combined with X-ray absorption spectra(XAFS),atomic force microscopy,and density functional theory calculation analysis,the Fe–N_(4) can be used as the polarization center to increase dipole polarization,interface polarization and defect-induced polarization due to d-p orbital hybridization and structural ***,electron migration within the Fe further leads to conduction loss,thereby synergistically promoting energy *** study demonstrates the effectiveness of metal-nitrogen doping in regulating the graphene′s dielectric properties,which provides an important basis for further investigation of the loss mechanism.

关键词： Electromagnetic wave absorption Fe-N-RGO Dipole polarization Conduction loss Impedance matching

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Principle and key technology of generalized high precision simulation of TT&C channel

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Journal of Systems Engineering and Electronics 2013年第2期24卷 318-323页

作者： Yang Zhou Zhe Zheng Siliang Wu School of Information and Electronics Beijing Institute of Technology

A generalized simulation method of the tracking,telemetry and control（TT＆C） channel,which is applicable to wideband and arbitrary radio frequency（RF） signal,is *** can accurately simulate the dynamic transmission delay of the arbitrary RF signal in channels,especially regardless of any prior knowledge including signal form,signal parameters,and so *** proposed method orthogonally demodulates the wideband and arbitrary RF signal to complex baseband by a known local oscillator（LO） ***,it takes measures to obtain the delay reconstruction signal of baseband signals based on the dynamic transmission delay between a ground station and a ***,it manages to obtain the delay reconstruction signal of LO *** simulation output signal（the delayed RF signal） can be achieved through the synthesis of the two delay reconstruction signals mentioned *** principle and its related key technology are described in detail,and the realizable system architecture is given.

关键词： generalization channel simulation high precision dynamic delay reconstruction dynamic delay cancellation

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Robust adaptive control of hypersonic vehicle considering inlet unstart

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Journal of Systems Engineering and Electronics 2022年第1期33卷 188-196页

作者： WANG Fan FAN Pengfei FAN Yonghua XU Bin YAN Jie College of Astronautics Northwestern Polytechnical UniversityXi’an 710072China College of Automation Northwestern Polytechnical UniversityXi’an 710072China

In this paper,a model reference adaptive control(MRAC)augmentation method of a linear controller is proposed for air-breathing hypersonic vehicle(AHV)during inlet *** the development of hypersonic flight technology,hypersonic vehicles have been gradually moving to the stage of *** the maneuvers,changes of attitude,Mach number and the back pressure can cause the inlet unstart phenomenon of *** unstart causes significant changes in the aerodynamics of AHV,which may lead to deterioration of the tracking performance or instability of the control ***,we firstly establish the model of hypersonic vehicle considering inlet unstart,in which the changes of aerodynamics caused by inlet unstart is described as nonlinear ***,an MRAC augmentation method of a linear controller is proposed and the radial basis function(RBF)neural network is used to schedule the adaptive parameters of ***,the Lyapunov function is constructed to prove the stability of the proposed ***,numerical simulations show that compared with the linear control method,the proposed method can stabilize the attitude of the hypersonic vehicle more quickly after the inlet unstart,which provides favorable conditions for inlet restart,thus verifying the effectiveness of the augmentation method proposed in the paper.

关键词： air-breathing hypersonic vehicle(AHV) inlet unstart model reference adaptive control augmentation(MRAC) radial basis function(RBF)neural network

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A hollow tubular NiCo layacknered double hydroxide@Ag nanowire structure for high-power-density flexible aqueous Ni//Zn battery

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Journal of Energy Chemistry 2022年第7期31卷 593-603,I0015页

作者： Xiaoyang Xuan Min Qian Likun Pan Ting Lu Yang Gao Lu Han Lijia Wan Yueping Niu Shangqing Gong School of Physics East China University of Science and TechnologyShanghai 200237China shanghai Key Laboratory of Magnetic Resonance School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237China

Flexible aqueous Ni//Zn batteries have attracted much attention as promising candidates for energy storage in the field of flexible ***,the Ni-based cathodes still face the challenges of poor conductivity,confined charge/mass transfer,and *** this work,we designed a hollow tubular structure consisting of a conductive silver nanowire (Ag NW) wrapped by active Ni Co layered double hydroxide (LDH),for enhancing the electrical conductivity,improving the charge/mass transfer kinetics,and facilitating the ion *** optimizing the contents of Ni,Co and Ag NW,the Ni_(4)Co LDH@Ag_(1.5)NW composite shows a maximum specific capacity of 115.83 m Ah g^(-1)at 0.1 A g^(-1)measured in a two-electrode ***,the flexible aqueous Ni//Zn battery assembled by Ni_(4)Co LDH@Ag_(1.5)NW interwoven with multi-walled carbon nanotube cathode and Zn foil anode realizes a high power density of 160μW cm^(-2)at the energy density of 23.14μWh cm^(-2),which is superior compared with those of oxide/hydroxide based devices and even higher than those of many carbon-based supercapacitors,showing its promising potentials for flexible energy storage applications.

关键词： NiCo layered double hydroxide Silver nanowire Hollow tubular morphology Flexible Ni//Zn battery

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DBS imaging based on Keystone transform

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Journal of Systems Engineering and Electronics 2012年第3期23卷 342-348页

作者： Jing Tian Wei Cui Lin Ma Siliang Wu Radar Research Institute Beijing Institute of TechnologyBeijing 100081E R.China

To correct the range walk through resolution cell in Doppler beam sharpening （DBS） imaging, a new DBS imaging algorithm based on Keystone transform is proposed. Without the exact values of the movement parameters and the look angle of the radar platform in the multi-targets environment, a linear trans- form on the received data is employed to correct different range walk values accurately under the condition of Doppler frequency ambiguity in this algorithm. This method can realize the cohe- rent integration in azimuth dimension and improve the azimuth resolution. In order to reduce the computational burden, a fast implementation of Keystone transform is used. Theoretical anal- ysis and simulation results demonstrate the effectiveness of the new algorithm. And through comparing the computational load of the fast implementation with several other algorithms, the real-time processing ability of the proposed algorithm is superior to that of other algorithms.

关键词： Doppler beam sharpening (DBS) Keystone transform range walk coherent integration.

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A Novel Generalized Simulation technology of aerospace TT&C Channel

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Chinese Journal of Electronics 2014年第1期23卷 204-208页

作者： ZHOU Yang ZHENG Zhe WU Siliang School of Information and Electronics Beijing Institute of Technology

A novel generalized simulation method is proposed to simulate the dynamic transmission delay of wideband and arbitrary signal in aerospace Tracking,telemetry and command(TT&C) channel. This method orthogonally demodulates the wideband and arbitrary Radio-frequency(RF) signal into complex baseband by a Local oscillator(LO) signal. Then the method of dynamic interpolation and delay reconstruction is proposed to obtain the delay reconstruction signal of complex baseband signal based on the variation rules of satellite-to-earth location. Meanwhile, the method of satellite-to-earth distance subsection and polynomial fitting is applied to obtain the delay reconstruction signal of LO signal. The simulated output signal is achieved through the synthesis of two delay reconstruction signals mentioned above. The proposed method can accurately simulate the variation characteristics of time delay and Doppler when wideband and arbitrary RF signal transmits in channel, without knowing any priori knowledge, such as signal form, signal parameters,and so on.

关键词： Generalization Simulation High precision dynamic interpolation and delay reconstruction Satellite-to-earth distance subsection and polynomial fitting

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Si/TiO_(2) carbon fiber core encapsulated in hierarchical multiple MXene@Co-MoS_(2) shells for constructing a free-standing anode of lithium storage

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Rare Metals 2024年第9期43卷 4222-4233页

作者： Xian-ping Du Ying Huang Jia-ming Wang Zhen-he Feng Xu Sun MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China shanghai Institute of Space Power-Sources Shanghai 200245China Ningbo Institute of Northwestern Polytechnical University Ningbo 315103China

Silicon-based(Si-based) materials offer more possibilities for generating new portable electronic devices due to their high specific capacities. However, their inferior electrical conductivity and volume expansion during cycling seriously limit their development. The optimum solution is to select specific materials to establish an exceptionally conductive and volume buffer structure,which can assist Si materials in developing their excellent lithium storage properties. In this study, Si particles were confined in TiO_(2)carbon fibers(TiO_(2)CFs) via electrospinning, after which they were encapsulated with MXene and Co-MoS_(2)(CMS) nanosheets to fabricate hierarchical ST-2@MXene@CMS films. TiO_(2)CF, MXene and CMS were employed to establish a coherent conductive network with one-, two-and three-dimensional electronic pathways to permit the unimpeded flow of electrons inside the electrode material. TiO_(2)CF, MXene and CMS acted precisely as multilayered buffers to ameliorate the volume change of Si particles during cycling. In addition, the CMS nanosheets were involved in lithium storage, contributing to the final electrochemical performance. Ultimately, the ST-2@MXene@CMS films served as free-standing electrodes, avoiding the impact of inactive interfaces on the electrochemical performance and fulfilling the lightweight requirement for new energy storage devices.

关键词： Si particles MXene Co-MoS_(2)nanosheets Hierarchical structure Lithium-ion batteries

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A soft sensor for industrial melt index prediction based on evolutionary extreme learning machine

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Chinese Journal of Chemical Engineering 2016年第8期24卷 1013-1019页

作者： Miao Zhang Xinggao Liu Zeyin Zhang State Key Laboratory of Industrial Control technology Department of Control Science and Engineering Zhejiang University Department of Mathematics Zhejiang University

In propylene polymerization(PP) process, the melt index(MI) is one of the most important quality variables for determining different brands of products and different grades of product quality. Accurate prediction of MI is essential for efficient and professional monitoring and control of practical PP processes. This paper presents a novel soft sensor based on extreme learning machine(ELM) and modified gravitational search algorithm(MGSA) to estimate MI from real PP process variables, where the MGSA algorithm is developed to find the best parameters of input weights and hidden biases for ELM. As the comparative basis, the models of ELM, APSO-ELM and GSAELM are also developed respectively. Based on the data from a real PP production plant, a detailed comparison of the models is carried out. The research results show the accuracy and universality of the proposed model and it can be a powerful tool for online MI prediction.

关键词： Propylene polymerization Melt index prediction Extreme learning machine Gravitational search algorithm

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Testability evaluation using prior information of multiple sources

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Chinese Journal of Aeronautics 2014年第4期27卷 867-874页

作者： Wang Chao Qiu Jing Liu Guanjun Zhang Yong science and technology on Integrated Logistics Support Laboratory National University of Defense Technology College of Mechatronic Engineering and Automation National University of Defense Technology

Testability plays an important role in improving the readiness and decreasing the lifecycle cost of equipment. Testability demonstration and evaluation is of significance in measuring such testability indexes as fault detection rate（FDR） and fault isolation rate（FIR）, which is useful to the producer in mastering the testability level and improving the testability design, and helpful to the consumer in making purchase decisions. Aiming at the problems with a small sample of testability demonstration test data（TDTD） such as low evaluation confidence and inaccurate result, a testability evaluation method is proposed based on the prior information of multiple sources and Bayes theory. Firstly, the types of prior information are analyzed. The maximum entropy method is applied to the prior information with the mean and interval estimate forms on the testability index to obtain the parameters of prior probability density function（PDF）, and the empirical Bayesian method is used to get the parameters for the prior information with a success-fail form. Then, a parametrical data consistency check method is used to check the compatibility between all the sources of prior information and TDTD. For the prior information to pass the check, the prior credibility is calculated. A mixed prior distribution is formed based on the prior PDFs and the corresponding credibility. The Bayesian posterior distribution model is acquired with the mixed prior distribution and TDTD, based on which the point and interval estimates are ***, examples of a flying control system are used to verify the proposed method. The results show that the proposed method is feasible and effective.

关键词： Bayes theory Consistency check Multiple sources Prior credibility Prior information Testability evaluation

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High-speed maneuvering target detection approach based on joint RFT and keystone transform

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science China(Information sciences) 2013年第6期56卷 93-105页

作者： TIAN Jing CUI Wei SHEN Qing WEI ZiXiang WU SiLiang Radar Research Laboratory Beijing Institute of Technology

Increasing the integration time is an effective method to improve small maneuvering target detection performance in radar ***,range migration and Doppler spread caused by maneuvering target motion during the integration time make it difficult to improve the coherent accumulation of target's energy and detection *** this study,a new method based on Radon Fourier transform(RFT) and keystone transform(KT) for high-speed maneuvering target detection is *** proposed algorithm utilizes second-order KT to correct the range curvature,and the improved dechirping method to compensate for the Doppler *** is then used to correct the range walk for target coherent *** method is capable of correcting the range migration and the time-varied Doppler frequency of the target without knowing its velocity and *** advantage of the proposed method is that it can increase the coherent integration time and improve detection performance under the condition of Doppler frequency *** with the second-order RFT algorithm,the computational burden of the proposed method is greatly reduced under the premise that the two methods have similar estimation accuracy of range,velocity and *** experiments demonstrate the validity of the proposed algorithm.

关键词： high-speed maneuvering target range migration correction Doppler spread coherent integration keystone transform

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