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Prescribed time control based on the periodic delayed sliding mode surface without singularities

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Science China(Information Sciences) 2024年第7期67卷 256-270页

作者： Bin ZHOU Yi ding kang-kang ZHANG Guang-Ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, nonsingular prescribed-time control is studied based on periodic delayed sliding mode surfaces. Different from the existing sliding mode control, where either singularity problems may appear or the convergence time depends on the initial state, the proposed sliding mode control approaches can achieve prescribed-time convergence without singularity. The proposed nonsingular sliding mode control approaches can be applied to both second-order and high-order nonlinear systems with prescribed-time convergence. As applications of the proposed sliding mode control approaches, the control of hypersonic vehicle systems is revisited. Numerical simulations on the nonlinear model of the hypersonic vehicle system show the effectiveness of the proposed methods.

关键词： prescribed-time control smooth periodic delayed feedback sliding mode control high-order nonlinear systems hypersonic vehicle systems

Construction of ZnO@CDs@Co_(3)O_(4) sandwich heterostructure with multi-interfacial electron-transfer toward enhanced photocatalytic CO_(2) reduction

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Chinese Chemical Letters 2024年第4期35卷 147-152页

作者： Xiuzheng Deng Yi Ke Jiawen ding Yingtang Zhou Hui Huang Qian Liang Zhenhui kang Advanced Catalysis and Green Manufacturing Collaborative Innovation Center CNPC-CZU Innovation AllianceSchool of Petrochemical EngineeringChangzhou UniversityChangzhou 213164China Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou 215123China Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control National Engineering Research Center for Marine AquacultureMarine Science and Technology CollegeZhejiang Ocean UniversityZhoushan 316004China

Photocatalytic conversion of CO_(2) into small-molecule chemical feedstocks can meet the growing demand for energy and alleviate the global warming. Herein, a p-n ZnO@CDs@Co_(3)O_(4) heterojunction with sandwich structure was constructed by calcination method of self-assembled ZIF-8@CDs@ZIF-67. The ZnO@CDs@Co_(3)O_(4) with well-defined interfacial structure exhibited the significantly enhanced photocatalytic CO_(2) reduction activity, and the optimal catalyst indicated the(CO + CH_(4)) evolution rate of 214.53μmol g^(-1)h^(-1) under simulated solar light, which was superior to ZnO, Co_(3)O_(4) and binary ZnO@Co_(3)O_(4).The internal cavity, exposed active sites, multiple interfaces and constructed p-n heterojunction can facilitate the light harvesting and photoexcited electron transfer. Besides, after introduction of CDs placed in the middle layer between ZnO and Co_(3)O_(4), CDs with excellent photoelectric property further promoted charge separation and migration. This work represents an appealing strategy to construct well-defined photocatalysts for boosting CO_(2) photoreduction.

关键词： Metal-organic framework Photocatalytic CO_(2) reduction Carbon dots p-n heterojunction Sandwich heterostructure

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Gradient sparsification for efficient wireless federated learning with differential privacy

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Science China(Information Sciences) 2024年第4期67卷 272-288页

作者： kang WEI Jun LI Chuan MA Ming ding Feng SHU Haitao ZHAO Wen CHEN Hongbo ZHU School of Electronic and Optical Engineering Nanjing University of Science and Technology Zhejiang Lab Key Laboratory of Computer Network and Information Integration(Southeast University) Ministry of Education Data61 Commonwealth Scientific and Industrial Research Organisation School of Information and Communication Engineering Hainan University School of Communications and Information Engineering Nanjing University of Posts and Telecommunications School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University

Federated learning(FL) enables distributed clients to collaboratively train a machine learning model without sharing raw data with each other. However, it suffers from the leakage of private information from uploading models. In addition, as the model size grows, the training latency increases due to the limited transmission bandwidth and model performance degradation while using differential privacy(DP)protection. In this paper, we propose a gradient sparsification empowered FL framework with DP over wireless channels, to improve training efficiency without sacrificing convergence performance. Specifically, we first design a random sparsification algorithm to retain a fraction of the gradient elements in each client’s local model, thereby mitigating the performance degradation induced by DP and reducing the number of transmission parameters over wireless channels. Then, we analyze the convergence bound of the proposed algorithm, by modeling a non-convex FL problem. Next, we formulate a time-sequential stochastic optimization problem for minimizing the developed convergence bound, under the constraints of transmit power, the average transmitting delay, as well as the client’s DP requirement. Utilizing the Lyapunov drift-plus-penalty framework, we develop an analytical solution to the optimization problem. Extensive experiments have been implemented on three real-life datasets to demonstrate the effectiveness of our proposed algorithm. We show that our proposed algorithms can fully exploit the interworking between communication and computation to outperform the baselines, i.e., random scheduling, round robin, and delay-minimization algorithms.

关键词： federated learning differential privacy gradient sparsification Lyapunov drift convergence analysis

Design strategies for rechargeable aqueous metal-ion batteries

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Science China Chemistry 2024年第1期67卷 165-190页

作者： Yang Li Xin Zhao Yifu Gao Yichen ding Zhichun Si Liubing Dong Dong Zhou Feiyu kang Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China College of Chemistry and Materials Science Jinan UniversityGuangzhou 511443China

Rechargeable aqueous metal-ion batteries(AMBs)have attracted extensive scientific and commercial interest due to their potential for cost-effective,highly safe,and scalable stationary energy ***,their limited output voltage,inadequate energy density,and poor reversibility of ambiguous electrode reactions in aqueous electrolytes strongly limit their practical *** review aims to elucidate the challenges of existing AMBs from the material design to whole device *** summarize the emerging electrochemistry,fundamental properties,and key issues in interfacial behaviors of various classes of prevailing AMBs,including aqueous alkali metal-ion batteries and multivalent-ion batteries,and present an appraisal of recent advances for addressing the performance ***,the progress of zinc-ion batteries is highlighted to provide a ubiquitous guideline for their commercialization in the grid-scale energy ***,we figure out the dominating general challenges for achieving high-performance AMBs,laying out a perspective for future breakthroughs.

关键词： aqueous metal-ion batteries aqueous alkali metal-ion batteries zinc-ion batteries interfacial behavior stationary energy storage

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Novel strategy of multidimensional information encryption via multi-color carbon dots aggregation-induced emission

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Nano Research 2024年第6期17卷 5680-5687页

作者： Liu ding Xilang Jin Yuchong Gao Shouwang kang Haiyan Bai Xuehao Ma Taotao Ai Hongwei Zhou Weixing Chen Shaanxi Key Laboratory of Photoelectric Functional Materials and Devices Engineering Research Center of Light Stabilizers for Polymer Materials Universities of Shaanxi Province School of Materials and Chemical EngineeringXi’an Technological UniversityXi’an 710021China School of Material Science and Engineering Shaanxi University of TechnologyHanzhong 723000China Department of Materials Science and Engineering University of PennsylvaniaPhiladelphia 19104USA

Carbon dots(CDs)with aggregation-induced emission(AIE)have sparked significant interest in multidimensional anti-counterfeiting due to their exceptional fluorescence ***,the preparation of AIE CDs with multicolor solid-state fluorescence remains a formidable challenge due to its complicated *** the present work,a novel class of multicolor AIE CDs(M-CDs)were fabricated using selected precursor(salicylic acid,thiosalicylic acid,and 2,2'-dithiodibenzoic acid),with an eco-friendly,low-cost one-pot solvothermal *** the dilute organic solution,M-CDs manifested blue emission,but upon aggregation in the presence of water,the red,yellow,green,and blue emissions were displayed due to the AIE *** analysis,coupled with theoretical calculations,revealed that the increase in the size of sp2 domains would lower the Eg and cause a red-shift emission ***,the continuous emission of M-CDs from blue to red can be utilized as ink for multimode printing,enabling the creation of a variety of school badges and quick response *** findings hold promising implications for multi-information encryption applications.

关键词： aggregation-induced emission(AIE) luminescence mechanism multi-color emission information encryption.

Electronic structure tuning of layered double hydroxides for electrochemical sensing and its biomedical applications

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Science China Chemistry 2024年第11期67卷 3614-3630页

作者： Kun Wang Zhiying Cao Qihang ding Jiyoung Yoo Nem Singh Heemin kang Lin Wang Lin Xu Jong Seung Kim School and Hospital of Stomatology Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling Jilin University State Key Laboratory on Integrated Optoelectronics Collage of Electronic Science and Engineering Jilin University Department of Chemistry Korea University Department of Materials Science and Engineering Korea University

Modifying the electrodes of electrochemical sensors is critical to enhance sensitivity, selectivity, and stability, ultimately improving both their effectiveness and performance. In this paper, recent advancements in electrochemical sensors are reviewed,focusing on the utilization of layered double hydroxides(LDHs). The first section explores the advantageous and disadvantageous aspects of electrochemical sensing. Benefits include rapid response, ease of operation, and cost-effectiveness,while drawbacks concern the potential instability of prolonged use, susceptibility to interference, and the risk of biomolecule inactivation. Following this, the second section delves into the synthesis, constituents, and structure of LDHs. Moreover, after introducing the chemical mechanisms and functions of LDHs in electrochemical sensors, we concentrate on diverse modifying materials of LDHs and their different performances. Finally, the applications of LDHs in electrochemical sensing across different fields are discussed. This review aims to facilitate the continued advancement for applying LDHs in electrochemical sensors, as well as inspire the evolution of electrochemical sensing technology.

关键词： layered double hydroxides electrochemical sensor biological field modified electrode

Local tetragonal distortion of Pt alloy catalysts for enhanced oxygen reduction reaction efficiency

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Carbon Energy 2024年第7期6卷 41-52页

作者： Xiaoke Li Xiao Duan kang Hua Yongkang Wu Zhiyan Rui Rui ding Aidong Li Chen Ouyang Jia Li Ting Li Jianguo Liu National Laboratory of Solid-State Microstructures College of Engineering and Applied Sciencesand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjingChina Long-Life Fuel Cell Key Laboratory in Sichuan Province Dongfang Electric(Chengdu)Hydrogen Fuel Cell Technology Co.Ltd.ChengduChina Institute of Energy Power Innovation North China Electric Power UniversityBeijingChina

Platinum-based alloy nanoparticles are the most attractive catalysts for the oxygen reduction reaction at present,but an in-depth understanding of the relationship between their short-range structural information and catalytic performance is still ***,we present a synthetic strategy that uses transition-metal oxide-assisted thermal ***/C catalysts with localized tetragonal distortion were obtained by controlling the thermal diffusion process of transition-metal *** localized structural distortion induced a significant strain effect on the nanoparticle surface,which further shortened the length of the Pt-Pt bond,improved the electronic state of the Pt surface,and enhanced the performance of the ***/C catalysts with special short-range structures achieved excellent mass activity(2.27 Amg_(Pt)^(-1))and specific activity(3.34 A cm^(-2)).In addition,the localized tetragonal distortion-induced surface compression of the Pt skin improved the stability of the *** mass activity decreased by only 13%after 30,000 *** catalyst activity and excellent durability have also been demonstrated in the proton exchange membrane fuel cell *** study provides valuable insights into the development of advanced Pt-based nanocatalysts and paves the way for reducing noble-metal loading and increasing the catalytic activity and catalyst stability.

关键词： electrocatalysts fuel cells local tetragonal distortion oxygen reduction

A Bibliometric Analysis of Global Research Trends of Exercise in Oncology During the Past Three Decades

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Journal of Clinical and Nursing Research 2024年第4期8卷 219-224页

作者： Qiaoli kang Yina ding ZheJiang Cancer Hospital Hangzhou 310000Zhejiang ProvinceChina

Recently, studies have found that exercise can promote recovery in cancer patients. Based on bibliometric analysis, this paper discusses the trends and hot spots of exercise oncology research in the past 30 years. The Science Citation Index Expanded of the Web of Science Core Collection (WoSCC) was searched to obtain information on publications and records published between 1993 to *** and CiteSpace were used to conduct bibliometric and visual analyanalysis on the overall distribution of keywords and highly cited papers, and a total of 1775 articles were retrieved. Harvard University was the institution with the highest number of publications and Fearon ranked first in 2013 with a total of 605 citations.

关键词： Exercise oncology Physical activity Cancer Quality of life Survivors Prevention Consensus

Realizing a dendrite-free metallic-potassium anode using reactive prewetting chemistry

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eScience 2024年第2期4卷 108-116页

作者： Lu-kang Zhao Xuan-Wen Gao Qinfen Gu Xiaochen Ge Zhimin ding Zhaomeng Liu Wen-Bin Luo Institute for Energy Electrochemistry and Urban Mines Metallurgy School of MetallurgyNortheastern UniversityShenyang 110819China Australian Synchrotron(ANSTO) 800 Blackburn RdClaytonVictoria 3168Australia School of Metallurgy and Environment Central South UniversityChangsha 410083China

Potassium metal batteries(PMBs)have become a paramount alternative energy storage technology to lithium-ion batteries,due to their low cost and potential energy ***,uncontrolled dendrite growth interferes with the stability of the interfacial anode,leading to significant capacity degradation and safety ***,a facile reactive prewetting strategy is proposed to discourage dendrite growth by constructing a functional KF/Znrich hybrid interface layer on K *** KF/Zn@K anode design functions like an interconnected paddy field,stabilizing the anode interface through the preferential redistribution of Kþflux/electrons,continuous transport paths,and enhanced transport *** anticipated,symmetrical batteries exhibit an extended cycling lifetime of over 2000 h,with reduced voltage hysteresis at 0.5 mA cm^(-2) and 0.5 mAh cm^(-2).Furthermore,when the KF/Zn@K anode is applied to full batteries coupled with PTCDA,a boosted reversible capacity of 61.6 mAh g1 at 5 C is present over 3000 *** interfacial control creates rational possibilities for constructing highefficiency,stable K metal anodes.

关键词： Potassium metal battery Potassium dendrite Interface Artificial interface layer