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Set-Membership Filtering Approach to Dynamic Event-Triggered Fault Estimation for a Class of Nonlinear Time-Varying Complex Networks

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 638-648页

作者： Xiaoting Du Lei zou Maiying Zhong the College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China IEEE the College of Information Science and Technology Donghua UniversityShanghai 201620 the Engineering Research Center of Digitalized Textile and Fashion Technology Ministry of EducationShanghai 201620China

The present study addresses the problem of fault estimation for a specific class of nonlinear time-varying complex networks,utilizing an unknown-input-observer approach within the framework of dynamic event-triggered mechanism(deTM).In order to optimize communication resource utilization,the deTM is employed to determine whether the current measurement data should be transmitted to the estimator or *** guarantee a satisfactory estimation performance for the fault signal,an unknown-input-observer-based estimator is constructed to decouple the estimation error dynamics from the influence of fault *** aim of this paper is to find the suitable estimator parameters under the effects of deTM such that both the state estimates and fault estimates are confined within two sets of closed ellipsoid *** techniques of recursive matrix inequality are applied to derive sufficient conditions for the existence of the desired estimator,ensuring that the specified performance requirements are met under certain ***,the estimator gains are derived by minimizing the ellipsoid domain in the sense of trace and a recursive estimator parameter design algorithm is then ***,a numerical example is conducted to demonstrate the effectiveness of the designed estimator.

关键词： Dynamic event-triggered mechanism(deTM) fault estimation nonlinear time-varying complex networks set-member-ship filtering unknown input observer

Ecological network analysis reveals complex responses of tree species life stage interactions to stand variables

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Journal of Forestry Research 2024年第1期35卷 29-43页

作者： Hengchao zou Huayong Zhang Tousheng Huang Research Center for Engineering Ecology and Nonlinear Science North China Electric Power UniversityBeijing 102206People’s Republic of China

Tree interactions are essential for the structure,dynamics,and function of forest ecosystems,but variations in the architecture of life-stage interaction networks(LSINs)across forests is ***,we constructed 16 LSINs in the mountainous forests of northwest Hebei,China based on crown overlap from four mixed forests with two dominant tree *** results show that LSINs decrease the complexity of stand densities and basal areas due to the interaction cluster *** addition,we found that mature trees and saplings play different roles,the first acting as“hub”life stages with high connectivity and the second,as“bridges”controlling information flow with high *** the forests,life stages with higher importance showed better parameter stability within *** results reveal that the structure of tree interactions among life stages is highly related to stand *** efforts contribute to the understanding of LSIN complexity and provide a basis for further research on tree interactions in complex forest communities.

关键词： Tree interactions Life stages Interaction networks Ecological complexity

Convection-Permitting Simulations of Current and Future Climates over the Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第10期41卷 1901-1916页

作者： Liwei zou Tianjun ZHOU LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

The Tibetan Plateau(TP)region,also known as the“Asian water tower”,provides a vital water resource for downstream *** studies of water cycle changes over the TP have been conducted with climate models of coarse resolution in which deep convection must be *** this study,we present results from a first set of highresolution climate change simulations that permit convection at approximately 3.3-km grid spacing,with a focus on the TP,using the Icosahedral Nonhydrostatic Weather and Climate Model(ICON).Two 12-year simulations were performed,consisting of a retrospective simulation(2008–20)with initial and boundary conditions from ERA5 reanalysis and a pseudoglobal warming projection driven by modified reanalysis-derived initial and boundary conditions by adding the monthly CMIP6 ensemble-mean climate change under the SSP5-8.5 *** retrospective simulation shows overall good performance in capturing the seasonal precipitation and surface air *** the central and eastern TP,the average biases in precipitation(temperature)are less than−0.34 mm d−1(−1.1℃)throughout the *** simulated biases over the TP are ***(wet)biases are found in summer(winter)above 5500 *** future climate simulation suggests that the TP will be wetter and warmer under the SSP5-8.5 *** general features of projected changes in ICON are comparable to the CMIP6 ensemble projection,but the added value from kilometer-scale modeling is evident in both precipitation and temperature projections over complex topographic *** ICON-downscaled climate change simulations provide a high-resolution dataset to the community for the study of regional climate changes and impacts over the TP.

关键词： dynamical downscaling convection-permitting Tibetan Plateau pseudo-global warming

Existence and asymptotics of normalized solutions for the logarithmic Schrödinger system

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Science China Mathematics 2024年第9期67卷 2019-2048页

作者： Qian Zhang Wenming zou department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

This paper is concerned with the following logarithmic Schrodinger system:{-Δu_(1)+ω_(1)u_(1)=u_(1)u_(1)logu_(1)^(2)+2p/p+q|u_(2)|^(q)|u_(1)|^(p-2)u_(1),-Δu_(2)+ω_(2)u_(2)=u_(2)u_(2)log u_(2)^(2)+2q/p+q|u_(1)|^(p)|u_(2)|^(q-2)u_(2),∫_(Ω)|u_(i)|^(2)dx=ρ_(i),i=1,2,(u_(1),u_(2))∈H_(0)^(1)(Ω;R^(2)),where Ω=R^(N)or Ω■R^(N)(N≥3)is a bounded smooth domain,andω_(i)R,μ_(i),ρ_(i)>0 for i=1,***,p,q≥1,and 2≤p+q≤2^(*),where 2^(*):=2N/*** using a Gagliardo-Nirenberg inequality and a careful estimation of u log u^(2),firstly,we provide a unified proof of the existence of the normalized ground state solution for all 2≤p+q≤2^(*).Secondly,we consider the stability of normalized ground state ***,we analyze the behavior of solutions for the Sobolev-subcritical case and pass to the limit as the exponent p+q approaches 2^(*).Notably,the uncertainty of the sign of u log u^(2)in(0,+∞)is one of the difficulties of this paper,and also one of the motivations we are interested *** particular,we can establish the existence of positive normalized ground state solutions for the Brézis-Nirenberg type problem with logarithmic perturbations(i.e.,p+q=2^(*)).In addition,our study includes proving the existence of solutions to the logarithmic type Bréis-Nirenberg problem with and without the L^(2)-*** ∫_(Ω)|u_(i)|^(2)dx=ρ_(i)(i=1,2)by two different methods,*** results seem to be the first result of the normalized solution of the coupled nonlinear Schrodinger system with logarithmic perturbations.

关键词： logarithmic Schrodinger system Brézis-Nirenberg problem normalized solution existence and stability behavior of solutions

Microstructure and properties of 35 kg large aluminum alloy flywheel housing components formed by squeeze casting with local pressure compensation

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China Foundry 2024年第5期21卷 563-576页

作者： Ju-fu Jiang Jing Yan Ying-ze Liu Ning Ge Ying Wang Chang-jie Ding de-chao zou School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China Dalian Innovation Die-casting Co. Ltd.Dalian 116600LiaoningChina

The squeeze casting method with local pressure compensation was proposed to form a flywheel housing component with a weight of 35 *** numerical simulation,microstructure observation and phase characterization were performed,and the influence of local pressure compensation on feeding of thick-wall position,microstructure and mechanical properties of the formed components were *** show that the molten metal keeps a good fluidity and the filling is complete during the filling *** the solidification at thick-wall positions of the mounting ports is slow,the local pressure compensation effectively realizes the local forced feeding,significantly eliminating the shrinkage cavity *** the microstructure of AlSi9Mg alloy,α-Al primarily consists of fragmented dendrites and rosette grains,while eutectic Si predominantly comprises needles and short *** impact of local pressure compensation on strength is relatively minimal,yet its influence on elongation is *** local pressure compensation,the average elongation at the compensated areas is 9.18%,which represents a 44.90%higher than that before *** average tensile strength is 209.1 MPa,and the average yield strength is 100.6 *** local pressure compensation can significantly reduce or even eliminate the internal defects in the 35 kg large-weight components formed by squeeze casting.

关键词： squeeze casting local pressure compensation aluminum alloy microstructure mechanical properties large flywheel housing components

Big Theta Equals Small Theta Generically

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Acta Mathematica Sinica,English Series 2024年第3期40卷 717-730页

作者： Rui CHEN Jia Liang zou Institute for Advanced Study in Mathmatics Zhejiang UniversityHangzhou 310058P.R.China department of Mathematics University of Michigan530 Church StAnn ArborMI 48109USA

In this paper we consider the theta correspondence over a non-Archimedean local *** the homological method and the theory of derivatives,we show that under a mild condition the bigtheta lift is irreducible.

关键词： Theta correspondence derivatives

Model-driven full system dynamics estimation of PMSM-driven chain shell magazine

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defence Technology（防务技术） 2024年第9期39卷 147-156页

作者： Kai Wei Longmiao Chen Quan zou School of Mechanical Engineering NanJing University of Science and TechnologyNanjing210094China

Based on the system dynamic model, a full system dynamics estimation method is proposed for a chain shell magazine driven by a permanent magnet synchronous motor(PMSM). An adaptive extended state observer(AESO) is proposed to estimate the unmeasured states and disturbance, in which the model parameters are adjusted in real time. Theoretical analysis shows that the estimation errors of the disturbances and unmeasured states converge exponentially to zero, and the parameter estimation error can be obtained from the extended state. Then, based on the extended state of the AESO, a novel parameter estimation law is designed. Due to the convergence of AESO, the novel parameter estimation law is insensitive to controllers and excitation signal. Under persistent excitation(PE) condition, the estimated parameters will converge to a compact set around the actual parameter value. Without PE signal, the estimated parameters will converge to zero for the extended state. Simulation and experimental results show that the proposed method can accurately estimate the unmeasured states and disturbance of the chain shell magazine, and the estimated parameters will converge to the actual value without strictly continuous PE signals.

关键词： Chain shell magazine Full system dynamics estimation Disturbance estimation Parameter estimation Adaptive extended state observer

Nearly degenerate ground states of a checkerboard antiferromagnet and their bosonic interpretation

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 84-89页

作者： Haiyuan zou Fan Yang Wei Ku Key Laboratory of Polar Materials and devices(MOE) School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China department of Physics Beijing Institute of TechnologyBeijing 100081China Tsung-Dao Lee Institute Shanghai 200240China Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education) Shanghai 200240China Shanghai Branch Hefei National LaboratoryShanghai 201315China

The spin-1/2 model system with antiferromagnetic(AF) couplings on a J1-J2checkerboard lattice, known as the planar pyrochlore model, is strongly frustrated and associated with a two-to-one dimensional crossover. Using the Projected Entangled Simplex States tensor network ansatz, we identify a large number of nearly degenerate states in the frustrated region(J_(1)des an intuitive understanding of the low-energy physics. Particularly, it predicts weaker VBS states in the easy-plane limit, which we confirm numerically. Our results clarify the most essential ground state properties of this interesting system and demonstrate the usefulness of bosonic picture in dealing with frustrated magnetism.

关键词： tensor networks frustrated magnetism dimensional crossover degenerate states

Precore mutation enhances viral replication to facilitate persistent infection especially in HBeAg-negative patients

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Virologica Sinica 2024年第2期39卷 319-330页

作者： Guixin Li Danli Yang Xin Liu Ting Zhang hui Liu Jun zou Zimeng Xu Xiangmei Chen Lizhong Dai Hongsong Chen Fengmin Lu Peking University People's Hospital Peking University Hepatology InstituteBeijing Key Laboratory of Hepatitis C and Immunotherapy for Liver DiseasesBeijing International Cooperation Base for Science and Technology on NAFLD DiagnosisBeijing100044China department of Microbiology and Infectious Disease Center School of Basic Medical SciencesPeking UniversityBeijing100191China Baruch S.Blumberg Institute DoylestownPA18901USA Shenzhen Sanyuansheng Biotechnology Co. LtdShenzhen518000China Precision Medicine Center of Zhengzhou University Academy of Medical SciencesZhengzhou UniversityZhengzhou450001China Peking University-Sansure Biotech Joint Laboratory of Molecular Medicine Sansure Biotech Co.LtdChangsha410205China

Naturally occurred precore(PC,G1896A)and/or basal core promoter(BCP,A1762T/G1764A)mutations are prevalent in chronic HBV-infected patients,especially those under HBeAg-negative ***,the replicative capacity of HBV with PC/BCP mutations remains ***,meta-analysis showed that,only under HBeAg-negative status,the serum HBV DNA load in patients with PC mutation was 7.41-fold higher than those without the *** PC mutation alone and BCPþPC mutations promoted HBV replication in cell and hydrodynamic injection mouse *** human hepatocyte chimeric mouse model,BCPþPC mutations led to elevated replicative capacity and intrahepatic core protein ***,preC RNA harboring PC mutation could serve as mRNA to express core and P proteins,and such pgRNA-like function favored the maintenance of cccDNA pool under HBeAg-negative ***,BCPþPC mutations induced more extensive and severe human hepatocyte damage as well as activated endoplasmic reticulum stress and TNF signaling pathway in livers of chimeric *** study indicates that HBeAg-negative patients should be monitored on HBV mutations regularly and are expected to receive early antiviral treatment to prevent disease progression.

关键词： Hepatitis B virus Precore mutation Basal core promoter mutations Endoplasmic reticulum stress