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iEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 1039-1050页

作者： chi Ma Dianbiao Dong the School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China

This paper studies the problem of time-varying formation control with finite-time prescribed performance for nonstrict feedback second-order multi-agent systems with unmeasured states and unknown *** eliminate nonlinearities,neural networks are applied to approximate the inherent dynamics of the *** addition,due to the limitations of the actual working conditions,each follower agent can only obtain the locally measurable partial state information of the leader *** address this problem,a neural network state observer based on the leader state information is ***,a finite-time prescribed performance adaptive output feedback control strategy is proposed by restricting the sliding mode surface to a prescribed region,which ensures that the closed-loop system has practical finite-time stability and that formation errors of the multi-agent systems converge to the prescribed performance bound in finite ***,a numerical simulation is provided to demonstrate the practicality and effectiveness of the developed algorithm.

关键词： Finite-time control multi-agent systems neural network prescribed performance control time-varying formation control

Opinion Dynamics in Two-Layer Networks with Hypocrisy

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Journal of the Operations Research Society of china 2024年第1期12卷 109-132页

作者： chi Zhao Elena Parilina Saint Petersburg State University Saint Petersburg199034Russia Qingdao University School of Mathematics and StatisticsQingdao 266071ShandongChina

We propose a general concealed voter model(GCVM),in which individuals interact in two layers and can exchange their opinions in the internal *** interaction is not allowed in a *** exchanging opinions in the internal layer,we mean that individuals share their real or internal opinions with their close *** process of opinion formation in GCVM is presented in the *** make the series of numerical simulations of GCVM with different network structures(both external and internal)and get some counterintuitive *** instance,we find out that sometimes with a relatively simple network structure of an external layer the consensus within the individuals’opinions cannot be reached,and if individuals in the network are not good at expressing their opinions publicly(in an external layer),exchanging opinions with their close friends(in an internal layer)is almost useless.

关键词： Opinion dynamics Voter model Concealed voter model General concealed voter model

Beyond the lab:a nanoimprint metalens arraybased augmented reality

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Light(Science & Applications) 2024年第5期13卷 801-802页

作者： chi Lio Haoran Ren School of Physics and Astronomy Monash UniversityMelbourneVICAustralia

A see-through augmented reality prototype has been developed based on an ultrathin nanoimprint metalens array,opening up a full-colour,video-rate,and low-cost 3D near-eye display.

关键词： cost ens imprint

Global collaboration of eye research--personal experience

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international Journal of Ophthalmology(English edition) 2024年第6期17卷 985-990页

作者： chi-Chao Chan Laboratory of immunology National Eye InstituteNational Institutes of HealthBethesdaMD 20892-1858USA Zhongshan Ophthalmic Center Sun Yat-sen UniversityGuangzhou 5410060Guangdong ProvinceChina

On December 9,2023,i was privileged to be honored and participate in the *** Chao Chan Symposium on Global Collaboration of Eye Research as the Global Eye Genetic Consortium(GEGC)session,which was held in the 16th Congress of the Asia-Pacific Vitreo-Retina Society(APVRS)in Hong *** with my talk on“Global collaboration of eye research:personal experience”,other prominent international speakers provided their own perspectives on opportunities for networking,collaboration,and exchange of ideas with global leaders and experts in ophthalmic practice,research,and education.

关键词： speakers collaboration Global

Fixed-Time Cluster Optimization for Multi-Agent Systems Based on Piecewise Power-Law Design

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iEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1301-1303页

作者： Suna Duan Xinchun Jia Xiaobo chi School of Mathematical Sciences Shanxi UniversityTaiyuan 030006China School of Automation and Software Engineering Shanxi UniversityTaiyuan 030013China

Dear Editor,This letter focuses on the fixed-time(FXT)cluster optimization problem of first-order multi-agent systems(FOMASs)in an undirected network,in which the optimization objective is the sum of the objective functions of all clusters.A novel piecewise power-law control protocol with cooperative-competition relations is ***,a sufficient condition is obtained to ensure that the FOMASs achieve the cluster consensus within an FXT.

关键词： agent cluster optimization

A Systematic Analysis of Early Life Exposure to the chinese Famine(1959-1961)and the Health of Older Adults-china,2008-2023

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china CDC weekly 2024年第11期6卷 203-207,I0001-I0003页

作者： chi Shen Xi Chen School of Public Policy and Administration Xi’an Jiaotong UniversityXi’an CityShaanxi ProvinceChina Department of Health Policy and Management Yale School of Public HealthNew HavenCTU.S Department of Economics Yale UniversityNew HavenCTU.S

What is already known about this topic?There is mounting evidence indicating that the aging process initiates during early life stages,with in utero the individual’s environment playing a significant ***,it is crucial to comprehend the enduring effects of early life circumstances on health in old *** is added by this report?in this study,we conducted a meta-analysis to examine the effects of the chinese Famine(1959–1961)on the health of older *** also explored potential mechanisms underlying these *** are the implications for public health practice?The complex interplay between early life circumstances,multiple health-related sectors,and healthy aging necessitates a comprehensive life-course approach and strategic interventions to enhance public health in an aging society.

关键词： life aging mount

Thermodynamic Performance Analysis of E/F/H-Class Gas Turbine Combined Cycle with Exhaust Gas Recirculation and inlet/Variable Guide Vane Adjustment under Part-Load Conditions

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Journal of Thermal Science 2024年第1期33卷 348-367页

作者： Li Keying chi Jinling WANG Bo ZHANG Shijie Key Lab of Advanced Energy and Power Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China University of chinese Academy of Sciences Beijing 100049China School of Mechanical Electronic&information Engineering China University of Mining&Technology-BeijingBeijing 100083China

Exhaust gas recirculation control(EGRC),an inlet air heating technology,can be utilized in combination with inlet/variable guide vane control(iGV/VGVC) and fuel flow control(FFC) to regulate the load,thereby effectively improving the part-load(i.e.,off-design) performance of the gas turbine combined cycle(GTCC).in this study,the E-,F-,and H-Class EGR-GTCC design and off-design system models were established and validated to perform a comparative analysis of the part-load performance under the EGR-iGV-FFC and conventional iGV-FFC strategies in the E/F/H-Class *** show that EGR-iGV-FFC has considerable potential for the part-load performance enhancement and can show a higher combined cycle efficiency than iGV-FFC in the E-,F-,and H-Class ***,the part-load performance improvement in the corresponding GTCC was weakened for the higher class of the gas turbine because of the narrower load range of EGR action and the deterioration of the gas turbine ***,EGR-iGV-FFC was inferior to iGV-FFC in improving the performance at loads below 50% for the H-Class *** results obtained in this paper could help guide the application of EGR-iGV-FFC to enhance the part-load performance of various classes of GTCC systems.

关键词： E/F/H-Class gas turbine combined cycle performance improvement part-load conditions exhaust gas recirculation inlet/variable guide vane

Honeycomb-like biochar framework coupled with Fe_(3)O_(4)/FeS nanoparticles as efficient heterogeneous Fenton catalyst for phenol degradation

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Journal of Environmental Sciences 2024年第2期136卷 390-399页

作者： Aihua Cheng Yi He Xiaohe Liu chi He Department of Environmental Engineering College of Geology and EnvironmentXi’an University of Science and TechnologyXi’an 710054China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China National Engineering Laboratory for VOCs Pollution Control Material and Technology University of Chinese Academy of SciencesBeijing 101408China

Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater ***,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by *** prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the ***,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation ***,biochar can effectively promote cycling stability by limiting Fe *** work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.

关键词： Biomass Biochar Fenton reaction Fe_(3)O_(4)/FeS(Fe/S) Phenol degradation

An impact sensitivity assessment method of spacecraft based on virtual exterior wall

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Defence Technology（防务技术） 2024年第1期31卷 142-157页

作者： Runqiang chi Yuyan Liu Diqi Hu Baojun Pang Hypervelocity impact Research Center Harbin Institute Of TechnologyHarbin150080China

The impact sensitivity assessment of spacecraft is to obtain the probability of spacecraft encountering the OD/M(orbital debris or meteoroid),which is a prerequisite for survivability assessment of on-orbit *** impact sensitivity assessment method of spacecraft based on virtual exterior wall was proposed to improve the computational *** method eliminates determination of the outermost surface elements of the spacecraft before generating the debris rays,which are assumed to originate from a non-concave virtual wall that completely wraps the *** Dist Mesh method was adopted for the generating of the virtual wall to ensure its mesh *** influences of the sizes,mesh densities,shapes of the virtual wall on the efficiency and accuracy were considered to obtain the best combination of the size and mesh density of the wall and *** results of this method were compared with those of S3DE(Survivability of Spacecraft in Space Debris Environment),BUMPER,MDPANTO,ESABASE2/Debris to verify the feasibility of the *** PchiP(Piecewise Cubic Hermite interpolating Polynomial)was used to fit the size *** relationship of the space debris to acquire the impact probability of OD/M with arbitrary size on the spacecraft.

关键词： Sensitivity OD/M Spacecraft Virtual exterior wall

The fast method and convergence analysis of the fractional magnetohydrodynamic coupled flow and heat transfer model for the generalized second-grade fluid

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Science china Mathematics 2024年第4期67卷 919-950页

作者： Xiaoqing chi Hui Zhang Xiaoyun Jiang School of Mathematics and Statistics Shandong UniversityWeihai 264209China School of Mathematics Shandong UniversityJinan 250100China

in this paper,we first establish a new fractional magnetohydrodynamic(MHD)coupled flow and heat transfer model for a generalized second-grade *** coupled model consists of a fractional momentum equation and a heat conduction equation with a generalized form of Fourier *** second-order fractional backward difference formula is applied to the temporal discretization and the Legendre spectral method is used for the spatial *** fully discrete scheme is proved to be stable and convergent with an accuracy of O(τ^(2)+N-r),whereτis the time step-size and N is the polynomial *** reduce the memory requirements and computational cost,a fast method is developed,which is based on a globally uniform approximation of the trapezoidal rule for integrals on the real *** strict convergence of the numerical scheme with this fast method is *** present the results of several numerical experiments to verify the effectiveness of the proposed ***,we simulate the unsteady fractional MHD flow and heat transfer of the generalized second-grade fluid through a porous *** effects of the relevant parameters on the velocity and temperature are presented and analyzed in detail.

关键词： fractional MHD coupled flow and heat transfer model generalized second-grade fuid fast method convergence analysis numerical simulation