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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

Mode-dependent dynamic gain of all-fiber FM-EDFA under various pump manipulation

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Chinese Optics Letters 2024年第2期22卷 128-134页

作者：方翼鸿张心怡黄锡恒曾研许鸥李建平付松年秦玉文 Institute of Advanced photonics technology School of Information EngineeringGuangdong University of TechnologyGuangzhou 510006China Guangdong Provincial key laboratory of Information photonics technology Guangdong University of TechnologyGuangzhou 510006China key laboratory of photonic technology for Integrated Sensing and Communication Ministry of EducationGuangdong University of TechnologyGuangzhou 510006China

The dynamic gain of a few-mode erbium-doped fiber amplifier(FM-EDFA)is vital for the long-haul mode division multiplexing(MDM)***,we investigate the mode-dependent dynamic gain of an FM-EDFA under various manipulations of the pump ***,we numerically calculate the gain variation with respect to the input signal power,where a modedependent saturation input power occurs under different pump *** under the fixed intensity profile of the pump laser,the saturation input power of each spatial mode is ***,high-order mode pumping leads to a compression of the linear amplification region,even though it is beneficial for the mitigation of the differential modal gain(DMG)arising in all guided ***,we develop an all-fiber 3-mode EDFA,where the fundamental mode of the pump laser can be efficiently converted to the LP_(11)mode using the all-fiber mode-selective coupler(MSC).In comparison with the traditional LP_(01)pumping scheme,the DMG at 1550 nm can be mitigated from 1.61 dB to 0.97 dB under the LP_(11)mode pumping,while both an average gain of 19.93 dB and a DMG of less than 1 dB can be achieved from 1530 nm to 1560 ***,the corresponding signal input saturation powers are reduced by 0.3 dB for the LP_(01)mode and 1.6 dB for the LP_(11)mode,*** theoretical and experimental results indicate that a trade-off occurs between the DMG mitigation and the extension of the linear amplification range when the intensity profile of pump laser is manipulated.

关键词： few-mode erbium-doped fiber amplifier differential modal gain saturation input power

State estimation for delayed switched positive systems: delayed radius approach

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Science China(Information Sciences) 2024年第8期67卷 190-205页

作者： Weizhong CHEN Zhongyang FEI Xudong ZHAO Zheng-Guang WU School of Electronics and Information Xi'an Polytechnic University Research Institute of Intelligent control and Systems Harbin Institute of Technology key laboratory of Intelligent control and Optimization for Industrial Equipment of Ministry of Education Dalian University of Technology School of control Science and Engineering Dalian University of Technology State key laboratory of Industrial control technology Institute of Cyber-Systems and ControlZhejiang University

In this paper, an interval estimation scheme is developed for delayed switched positive systems（DSPS） with mode-dependent average dwell time switching. A lossless zonotopic estimation approach is proposed for the delayed intersection zonotope with the positive generator matrix. First, considering the existence of asynchronism between the system mode and the correction matrix mode, the mismatched intersection zonotope is constructed for DSPS to verify the consistency between the system model and ***, by utilizing the introduced radius definitions, the ?∞performance is addressed to optimize the size of delayed intersection zonotopes. Subsequently, we present a joint-design approach of switching signals and the mode-dependent correction matrix by constructing positive generator matrix-based delayed radius functions. Furthermore, guaranteed nonnegative state bounds are derived for the considered DSPS based on the proposed lossless zonotopic estimation criteria. Finally, detailed simulations are conducted to validate the feasibility and superiority of the developed methods.

关键词： delayed switched positive systems interval estimation asynchronous correction matrix zonotopes mode-dependent average dwell time

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Ultra-wide band gap and wave attenuation mechanism of a novel star-shaped chiral metamaterial

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1261-1278页

作者： Shuo WANG Anshuai WANG Yansen WU Xiaofeng LI Yongtao SUN Zhaozhan ZHANG Qian DING G.D.AYALEW Yunxiang MA Qingyu LIN Department of Mechanics Tianjin University Tianjin key laboratory of Nonlinear Dynamics and control Tianjin University State key laboratory of Metastable Materials Science and technology Yanshan University

A novel hollow star-shaped chiral metamaterial(SCM) is proposed by incorporating chiral structural properties into the standard hollow star-shaped metamaterial, exhibiting a wide band gap over 1 500 Hz. To broaden the band gap,solid single-phase and two-phase SCMs are designed and simulated, which produce two ultra-wide band gaps(approximately 5 116 Hz and 6 027 Hz, respectively). The main reason for the formation of the ultra-wide band gap is that the rotational vibration of the concave star of two novel SCMs drains the energy of an elastic wave. The impacts of the concave angle of a single-phase SCM and the resonator radius of a two-phase SCM on the band gaps are studied. Decreasing the concave angle leads to an increase in the width of the widest band gap, and the width of the widest band gap increases as the resonator radius of the two-phase SCM increases. Additionally,the study on elastic wave propagation characteristics involves analyzing frequency dispersion surfaces, wave propagation directions, group velocities, and phase velocities. Ultimately, the analysis focuses on the transmission properties of finite periodic structures. The solid single-phase SCM achieves a maximum vibration attenuation over 800, while the width of the band gap is smaller than that of the two-phase SCM. Both metamaterials exhibit high vibration attenuation capabilities, which can be used in wideband vibration reduction to satisfy the requirement of ultra-wide frequencies.

关键词： metamaterial ultra-wide band gap wave propagation vibration suppression O421 + .5 74H45

Progress and challenges of electrolyte modulation in aqueous zinc-ion batteries

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Rare Metals 2024年第7期43卷 2940-2967页

作者： Qi-Hang Yang Lu-Fei Wang Xiao-Yu Wang Meng-Meng Zhen Tianjin key laboratory of Clean Energy and Pollution control School of Energy and Environmental EngineeringHebei University of Technology

As a new type of green battery system,aqueous zinc-ion batteries（AZIBs） have gradually become a research hotspot due to their low cost,high safety,excellent stability,high theoretical capacity(820 mAh·g-1) of zinc anode,and low redox potential(-0.76 V *** hydrogen electrode（SHE）).AZIBs have been expected to be an alternative to lithium-ion batteries for large-scale commercial energy storage ***,they are facing thorny issues such as degradation of cycling performance,zinc dendrites,and side *** the same time,these problems cause short cycling life of batteries,thus severely limiting their commercial *** recent years,many more researches have been conducted on the modification of anode and cathode materials of AZIBs,but there is a lack of in-depth discussion on the characteristics and mechanism of electrolyte *** this review,we will make a systematic summary of the current problems with two electrodes in AZIBs,as well as the types and functions of electrolyte ***,we further systematically describe the modulation mechanism of electrolyte additives in the performance of the cathode and *** prospects and development directions of additive modulation strategies for AZIBs electrolytes are prospected.

关键词： Electrolyte additives Aqueous zinc-ion batteries Zinc anode protection Cathode chemistry

Whittle’s Index Based Sensor Scheduling for Multiprocess Systems Under DoS Attacks

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Journal of Systems Science & Complexity 2024年第1期37卷 329-350页

作者： CAI Zai DING Kemi Shenzhen key laboratory of control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China.

In this paper,the authors consider how to design defensive countermeasures against DoS attacks for remote state estimation of multiprocess *** each system,a sensor will measure its state and transmits the data packets through an unreliable channel which is vulnerable to be jammed by an *** limited communication bandwidth,only a subset of sensors are allowed for data transmission,and how to select the optimal one to maximize the accuracy of remote state estimation is the focus of the proposed *** authors first formulate this problem as a Markov decision process and investigate the existence of optimal ***,the authors demonstrate the piecewise monotonicity structure of optimal *** the difficulty of obtaining an optimal policy of large-scale problems,the authors develop a suboptimal heuristic policy based on the aforementioned policy structure and Whittle’s ***,a closed form of the indices is derived in order to reduce implementation complexity of proposed scheduling policy and numerical examples are provided to illustrate the proposed developed results.

关键词： DoS attacks Kalman filter remote state estimation Whittle’s index.

Toward understanding the cross-linking from molecular chains to aggregates by engineering terminals of supramolecular hyperbranched polysiloxane

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Aggregate

Aggregate 2024年第1期5卷 228-235页

作者： Yuanbo Zhang Junshan Yuan Jingzhi Hu Zhixuan Tian Weixu Feng Hongxia Yan Shaanxi key laboratory of Macromolecular Science and technology Xi’an Key Laboratory of Hybrid Lumines-cent Materials and Photonic DeviceSchool of Chemistry and Chemical engineeringNorthwestern Polytechnical UniversityXi’anChina

Crosslinking thermosets with hyperbranched polymers confers them superior comprehensive ***,it still remains a further understanding of polymer crosslinking from the molecular chains to the role of *** this study,three hyperbranched polysiloxane structures(HBPSi-R)are synthesized as model macromolecules,each featuring distinct terminal groups(R denotes amino,epoxy,and vinyl groups)while similar molecular backbone(Si-O-C).These structures were subsequently copolymerized with epoxy monomers to construct interpenetrating HBPSi-R/epoxy/anhydride co-polymer *** spatial molecular configuration and flexible Si-O-C branches of HBPSi-R endow them with remarkable reinforcement and toughening ***,an optimum impact strength of 28.9 kJ mol^(−1) is achieved with a mere 3%loading of HBPSi-V,nearly three times that of the native epoxy(12.9 kJ mol^(−1)).By contrasting the terminal effects,the aggregation states and crosslinking modes were proposed,thus clarifying the supramolecular-dominant aggregation mechanism and covalent-dominant dispersion mechanism,which influences the resulting material *** work underscores the significance of aggregate science in comprehending polymer crosslinking and provides theoretical insights for tailoring material properties at a refined molecular level in the field of polymer science.

关键词： aggregates crosslinking hyperbranched polymers

Unified numerical predictor-corrector guidance based on characteristic model

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中国空间科学技术(中英文) 2024年第4期44卷 40-49页

作者： MENG Bin ZHANG Hangning ZHAO Yunbo Beijing Institute of control Engineering National key laboratory of Space Intelligent control University of Science and technology of China

Aerocapture is one of the key technologies for low-cost transportation, with high demands of autonomy, accuracy, and robustness of guidance and control, due to its high reliability requirements for only one chance of trying.A unified numerical predictor-corrector guidance method based on characteristic models for aerocapture is *** numerical predictor-corrector guidance method is used to achieve autonomy and high accuracy, and the characteristic model control method is introduced to achieve *** the same time, by transforming path constraints, characteristic model equations including apogee deviation and altitude differentiation are *** on the characteristic model equations, a unified guidance law which can satisfy path constraints and guidance objectives simultaneously is *** guidance problems, guidance deviation is not directly obtained from the output of the dynamics at present, but is calculated through integral and algebraic ***, the method of directly discretizing differential equations cannot be used to establish characteristic models, which brings great difficulty to characteristic modeling.A method for characteristic modeling of guidance problems is proposed, and convergence analysis of the proposed guidance law is also ***, a joint numerical simulation of guidance and control considering navigation deviation and various uncertainties is conducted to verify the effectiveness of the proposed *** proposed unified method can be extended to general aerodynamic entry guidance designs, providing theoretical and methodological support for them.

关键词： aerocapture characteristic model convergence path constraint unified numerical predictor-corrector guidance

A Tutorial on Quantized Feedback control

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 5-17页

作者： Minyue Fu IEEE the School of System Design and Intelligent Manufacturing Shenzhen Key Laboratory of Control Theory and Intelligent Systems and Centre for Control Science and TechnologySouthern University of Science and TechnologyShenzhen 518055China

In this tutorial paper, we explore the field of quantized feedback control, which has gained significant attention due to the growing prevalence of networked control systems. These systems require the transmission of feedback information, such as measurements and control signals, over digital networks, presenting novel challenges in estimation and control design. Our examination encompasses various topics, including the minimal information needed for effective feedback control, the design of quantizers, strategies for quantized control design and estimation,achieving consensus control with quantized data, and the pursuit of high-precision tracking using quantized measurements.

关键词： Consensus control high-precision control networked control quantized estimation quantized feedback control robust control