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Vanadium oxide nanospheres encapsulated in N-doped carbon nanofibers with morphology and defect dual-engineering toward advanced aqueous zinc-ion batteries

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Journal of Energy Chemistry 2024年第2期89卷 599-609,I0013页

作者： Yunfei Song Laiying Jing Rutian Wang Jiaxi Cui Mei Li Yunqiang Zhang School of Materials Science and Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353ShandongChina institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054SichuanChina

Vanadium-based electrodes are regarded as attractive cathode materials in aqueous zinc ion batteries(ZIBs)caused by their high capacity and unique layered ***,it is extremely challenging to acquire high electrochemical performance owing to the limited electronic conductivity,sluggish ion kinetics,and severe volume expansion during the insertion/extraction process of Zn^(2+).Herein,a series of V_(2)O_(3)nanospheres embedded N-doped carbon nanofiber structures with various V_(2)O_(3)spherical morphologies(solid,core-shell,hollow)have been designed for the first time by an electrospinning technique followed thermal *** N-doped carbon nanofibers not only improve the electrical conductivity and the structural stability,but also provides encapsulating shells to prevent the vanadium dissolution and aggregation of V_(2)O_(3)***,the varied morphological structures of V_(2)O_(3)with abundant oxygen vacancies can alleviate the volume change and increase the Zn^(2+)***,the phase transition between V_(2)O_(3)and Zn_XV_(2)O_(5-m)·n H_(2)O in the cycling was also *** a result,the as-obtained composite delivers excellent long-term cycle stability and enhanced rate performance for coin cells,which is also confirmed through density functional theory(DFT)*** assembled into flexible ZIBs,the sample still exhibits superior electrochemical performance,which may afford new design concept for flexible cathode materials of ZIBs.

关键词： Aqueous zinc ion batteries Vanadium trioxide Oxygen vacancy Structure evolution Phase optimization

Preliminary study of the electrospray DPE peculiarities from the liquid surface in the presence of the CSWs

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Plasma Science and technology 2024年第5期26卷 110-120页

作者：贺伟国霍卫杰韩罗峰朱康武王锋王泽坤 School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444People’s Republic of China Shanghai aerospace electronic technology institute Shanghai 201109People’s Republic of China Shanghai aerospace Control technology institute Shanghai 201109People’s Republic of China

The Ultrasonic Electric Propulsion(UEP)system is a cutting-edge propulsion technology that is mostly used on platforms for small satellites(less than 10 kg).The characteristics of droplet partial emissions(DPEs)in the UEP system are investigated using a high-speed imaging technique(an ultra-high speed camera(NAC HX-6)and a long-distance microscope)in this *** experiments demonstrate that there are a few partial emission modes,including left-side emission,double-side emission,and right-side emission,that are present in the droplet emission process of the UEP *** modes are primarily caused by the partial formation of capillary standing waves(CSWs)on the emission surface of the ultrasonic *** emission rate for single-and double-sided emissions varies at different times,indicating that there are different CSWs engaged in droplet emission due to variations in the liquid film thickness and charge state of the liquid ***,as the droplets emit continuously,a raised area on the emission surface appears,with several droplets emitting there as a result of charge ***,photos of the CSWs with emitting droplets are obtained,which highlights the CSWs'distinctive wave morphology.

关键词： ultrasonic electric propulsion system microsatellite high-speed imaging technique droplet partial emissions electric field

Unconditionally stable Crank-Nicolson algorithm with enhanced absorption for rotationally symmetric multi-scale problems in anisotropic magnetized plasma

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Journal of Systems Engineering and electronics 2024年第1期35卷 65-73页

作者： WEN Yi WANG Junxiang XU Hongbing School of Automatic Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Beijing institute of aerospace Systems Engineering Beijing 100076China

Large calculation error can be formed by directly employing the conventional Yee’s grid to curve *** order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized *** the CNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution *** perfectly matched layer(CPML)formulation is proposed to efficiently solve the open region *** example is carried out for the illustration of effectiveness including the efficiency,resources,and *** the results,it can be concluded that the proposed scheme shows considerable performance during the simulation.

关键词： anisotropic magnetized plasma body-of-revolution(BOR) Crank-Nicolson Douglas-Gunn(CNDG) finite-difference time-domain(FDTD) perfectly matched layer(PML) rotationally symmetric multi-scale problems

SAR regional all-azimuth observation orbit design for target 3D reconstruction

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Journal of Systems Engineering and electronics 2024年第3期35卷 609-618页

作者： WANG Yanan ZHOU Chaowei LIU Aifang MAO Qin Beijing institute of Tracking and Communication technology Beijing 100094China Nanjing Research institute of electronics technology Nanjing 210012China Shanghai aerospace electronic technology institute Shanghai 201109China

Three-dimensional(3D) synthetic aperture radar(SAR)extends the conventional 2D images into 3D features by several acquisitions in different aspects. Compared with 3D techniques via multiple observations in elevation, e.g. SAR interferometry(InSAR) and SAR tomography(TomoSAR), holographic SAR can retrieve 3D structure by observations in azimuth. This paper focuses on designing a novel type of orbit to achieve SAR regional all-azimuth observation(AAO) for embedded targets detection and holographic 3D reconstruction. The ground tracks of the AAO orbit separate the earth surface into grids. Target in these grids can be accessed with an azimuth angle span of360°, which is similar to the flight path of airborne circular SAR(CSAR). Inspired from the successive coverage orbits of optical sensors, several optimizations are made in the proposed method to ensure favorable grazing angles, the performance of 3D reconstruction, and long-term supervision for SAR sensors. Simulation experiments show the regional AAO can be completed within five hours. In addition, a second AAO of the same area can be duplicated in two days. Finally, an airborne SAR data process result is presented to illustrate the significance of AAO in 3D reconstruction.

关键词： synthetic aperture radar(SAR) orbit design all-azimuth observation(AAO) three-dimensional(3D)reconstruction successive coverage

MEMS reservoir computing system with stiffness modulation for multi-scene data processing at the edge

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Microsystems & Nanoengineering 2024年第3期10卷 421-432页

作者： Xiaowei Guo Wuhao Yang Xingyin Xiong Zheng Wang Xudong Zou The State Key Laboratory of Transducer technology Aerospace Information Research InstituteChinese Academy of SciencesBeijingChina School of electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijingChina QILU aerospace Information Research institute JinanChina

Reservoir computing(RC)is a bio-inspired neural network structure which can be implemented in hardware with *** has been applied across various fields such as memristors,and electrochemical reactions,among which the microelectro-mechanical systems(MEMS)is supposed to be the closest to sensing and computing *** previous MEMS RCs have demonstrated their potential as reservoirs,the amplitude modulation mode was found to be inadequate for computing directly upon *** achieve this objective,this paper introduces a novel MEMS reservoir computing system based on stiffness modulation,where natural signals directly influence the system stiffness as *** this innovative concept,information can be processed locally without the need for advanced data collection and *** present an integrated RC system characterized by small volume and low power consumption,eliminating complicated setups in traditional MEMS RC for data discretization and *** simulation and experiment were conducted on our *** performed nonlinearity tuning for the resonator and optimized the post-processing algorithm by introducing a digital mask ***,our MEMS RC is capable of both classification and forecasting,surpassing the capabilities of our previous non-delay-based *** method successfully processed word classification,with a 99.8%accuracy,and chaos forecasting,with a 0.0305 normalized mean square error(NMSE),demonstrating its adaptability for multi-scene data *** work is essential as it presents a novel MEMS RC with stiffness modulation,offering a simplified,efficient approach to integrate sensing and *** approach has initiated edge computing,enabling emergent applications in MEMS for local computations.

关键词： computing hardware stiffness

Fault Estimation for a Class of Markov Jump Piecewise-Affine Systems: Current Feedback Based Iterative Learning Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 418-429页

作者： Yanzheng Zhu Nuo Xu Fen Wu Xinkai Chen Donghua Zhou IEEE College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China College of Mechanical Engineering and Automation Huaqiao UniversityXiamen 361021China Department of Mechanical and aerospace Engineering North Carolina State UniversityRaleigh NC 27695 USA Department of electronic and Information Systems Shibaura Institute of TechnologySaitama 337-8570Japan

In this paper, the issues of stochastic stability analysis and fault estimation are investigated for a class of continuoustime Markov jump piecewise-affine(PWA) systems against actuator and sensor faults. Firstly, a novel mode-dependent PWA iterative learning observer with current feedback is designed to estimate the system states and faults, simultaneously, which contains both the previous iteration information and the current feedback mechanism. The auxiliary feedback channel optimizes the response speed of the observer, therefore the estimation error would converge to zero rapidly. Then, sufficient conditions for stochastic stability with guaranteed performance are demonstrated for the estimation error system, and the equivalence relations between the system information and the estimated information can be established via iterative accumulating ***, two illustrative examples containing a class of tunnel diode circuit systems are presented to fully demonstrate the effectiveness and superiority of the proposed iterative learning observer with current feedback.

关键词： Current feedback fault estimation iterative learning observer Markov jump piecewise-affine system

On-chip ultra-high rejection and narrow bandwidth filter based on coherency-broken cascaded cladding-modulated gratings

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Photonics Research 2024年第5期12卷 979-985页

作者： JINZHAO WANG TING LI YANG FENG JIEWEN LI WANXIN LI LUWEI DING YONG YAO JIANAN DUAN WEI LIU FENG HE YI ZOU XIAOCHUAN XU Guangdong Provincial Key Laboratory of Integrated Photonic-electronic Chip Guangdong Provincial Key Laboratory of Aerospace Communication and Networking TechnologyHarbin Institute of TechnologyShenzhenShenzhen 518055China School of Information Science and technology ShanghaiTech UniversityShanghai 201210China

Bragg filters are of essential importance for chip-scale photonic ***,the implementation of filters with sub-nanometer bandwidth and rejection beyond 70 dB is hindered by the high index contrast of the siliconon-insulator platform,which makes filters prone to fabrication *** this paper,we propose to combine coherency-broken cascading architecture and cladding modulation to circumvent the intrinsic *** cascading architecture effectively prevents the accumulation of phase errors,while the cladding modulation offers additional design freedom to reduce the coupling coefficient.A bimodal Bragg filter with a testingequipment-limited rejection level of 74 dB and a 40 dB bandwidth of 0.44 nm is experimentally *** minimum feature size is 90 nm,which significantly relieves the fabrication constraints.

关键词： filter cladding narrow

Enhancing alkaline water oxidation with NiFe alloy-encapsulated nitrogen-doped vertical graphene array

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Nano Research 2024年第6期17卷 4790-4796页

作者： Jue Nan Beirong Ye Xun He Chen Li Wanli Zhang Qian Liu Luming Li Wei Chu Xuping Sun Yongqi Zhang School of Integrated Circuit Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China institute of Fundamental and Frontier Science University of Electronic Science and Technology of ChinaChengdu 611731China institute for Advanced Study Chengdu UniversityChengdu 610106China College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJinan 250014China

Advancing efficient and affordable electrocatalysts to boost the oxygen evolution reaction(OER)is pivotal for sustainable green hydrogen ***,we propose the fabrication of nickel-iron alloy nanoparticles-encapsulated on N-doped vertically aligned graphene array on carbon cloth(NiFe@NVG/CC)as a highly active three-dimensional(3D)catalyst electrode for *** 1 M KOH,such NiFe@NVG/CC demonstrates outstanding catalytic performance,necessitating merely overpotential of 245 mV for achieving a current density of 10 mA·cm^(−2),a remarkably low Tafel slope of 36.2 mV·dec^(−1).Furthermore,density functional theory calculations validate that the incorporate of N species into graphene can reinforce the electrocatalytic activity though reducing the reaction energy barrier during the conversion of*O to*OOH *** outstanding performance and structural benefits of NiFe@NVG/CC offer valuable insights for the development of innovative and efficient electrocatalysts for water oxidation.

关键词： NiFe alloy N-doped vertical graphene array electrocatalyst oxygen evolution reaction density functional theory

Relaxed Stability Criteria for Time-Delay Systems:A Novel Quadratic Function Convex Approximation Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 996-1006页

作者： Shenquan Wang Wenchengyu Ji Yulian Jiang Yanzheng Zhu Jian Sun College of Electrical and electronic Engineering Changchun University of TechnologyChangchun 130012China the College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Complex Systems Intelligent Control and Decision Beijing Institute of TechnologyBeijing 100081China

This paper develops a quadratic function convex approximation approach to deal with the negative definite problem of the quadratic function induced by stability analysis of linear systems with time-varying *** introducing two adjustable parameters and two free variables,a novel convex function greater than or equal to the quadratic function is constructed,regardless of the sign of the coefficient in the quadratic *** developed lemma can also be degenerated into the existing quadratic function negative-determination(QFND)lemma and relaxed QFND lemma respectively,by setting two adjustable parameters and two free variables as some particular ***,for a linear system with time-varying delays,a relaxed stability criterion is established via our developed lemma,together with the quivalent reciprocal combination technique and the Bessel-Legendre *** a result,the conservatism can be reduced via the proposed approach in the context of constructing Lyapunov-Krasovskii functionals for the stability analysis of linear time-varying delay ***,the superiority of our results is illustrated through three numerical examples.

关键词： Equivalent reciprocal combination technique quadratic function convex approximation approach stability timevarying delay