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The recirculation flow after different cross-section shaped high-rise buildings with applications to ventilation assessment and drag parameterization

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Building Simulation 2024年第4期17卷 509-524页

作者： Keyi chen Ziwei Mo jian.Hang School of Atmospheric Sciences Sun Yat-sen University&Southern Marine Science and Engineering Guangdong LaboratoryZhuhai519082China Key Laboratory of Tropical Atmosphere-Ocean System Ministry of EducationZhuhai519000China

The building cross-section shape significantly affects the flow characteristics around buildings,especially the recirculation region behind the high-rise *** generic building shapes including square,triangle,octagon,T-shaped,cross-shaped,#-shaped,H-shaped and L-shaped are examined to elucidate their effects on the flow patterns,recirculation length L and areas A using computational fluid dynamics(CFD)simulations with Reynolds-averaged Navier-Stokes(RANS)*** sizes and positions of the vortexes behind the buildings are found to be substantially affected by the building shapes and subsequently changing the recirculation *** recirculation length L is in the range of 1.6b-2.6b with an average of *** maximum L is found for L-shaped building(2.6b)while the shortest behind octagon building(1.6b).The vertical recirculation area Av is in the range of 1.5b^(2)-3.2b^(2)and horizontal area Ah in 0.9b^(2)-2.2b^(2).The L,Av and Ah generally increase with increasing approaching frontal area when the wind direction changes but subject to the dent structures of the#-shaped and cross-shaped *** area-averaged wind velocity ratio(AVR),which is proposed to assess the ventilation performance,is in the range of 0.05 and 0.14,which is around a three-fold difference among the different building *** drag coefficient parameterized by Ah varies significantly,suggesting that previous models without accounting for building shape effect could result in large uncertainty in the drag *** findings provide important reference for improving pedestrian wind environment and shed some light on refining the urban canopy parameterization by considering the building shape effect.

关键词： recirculation region cross-section shape ventilation assessment drag parameterization computational fluid dynamics

Advances in the application of hydrogel-based scaffolds for tendon repair

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Genes & Diseases 2024年第4期11卷 296-313页

作者： Renqiang chen Fanglin chen Kenian chen jian.Xu Department of Orthopedics The First Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang 310003China Department of Orthopedics The Fourth Affiliated Hospital of Guangxi Medical UniversityLiuzhou Guangxi 545005China

Tendon injuries often lead to joint dysfunction due to the limited self-regeneration capacity of *** tendons is a major challenge for surgeons and imposes a signif-icant financial burden on ***,there is an urgent need to develop effective stra-tegies for repairing injured *** tissue engineering using hydrogels has emerged as a promising approach that has attracted considerable *** possess excellent biocompatibility and biodegradability,enabling them to create an extracellular matrix-like growth environment for *** can also serve as a carrier for cells or other substances to accelerate tendon *** the past decade,numerous studies have made significant prog-ress in the preparation of hydrogel scaffolds for tendon *** review aims to provide an overview of recent research on the materials of hydrogel-based scaffolds used for tendon tis-sue engineering and discusses the delivery systems based on them.

关键词： Application Hydrogel-based Repairscaffolds Review Tendon injury Tissue engineering

Data-Driven Active Disturbance Rejection Control of Plant-Protection Unmanned Ground Vehicle Prototype: A Fuzzy Indirect Iterative Learning Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1892-1894页

作者： Tao chen Ruiyuan Zhao jian.chen Zichao Zhang College of Engineering China Agricultural UniversityBeijing 100083China Key Laboratory of Smart Agricultural Technology in Tropical South China Ministry of Agriculture and Rural AffairsGuangzhou 510642China

Dear Editor,This letter proposes a fuzzy indirect iterative learning(FIIL)active disturbance rejection control(ADRC)scheme to address the impact of uncertain factors of plant-protection unmanned ground vehicle(UGV),in which ADRC is a data-driven model-free control algorithm that only relies on the input and output data of the *** on the established nonlinear time-varying dynamic model including dynamic load(medicine box),the FIIL technology is adopted to turn the bandwidth and control channel gain online,in which the fuzzy logic system is used to update the gain parameters of iterative learning in real *** and experiment show the FIIL-ADRC scheme has better control performance.

关键词： Active scheme iterative

Generalized Inverses and Units in a Unitary Ring

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1000-1014页

作者： Yu Kun ZHOU jian.Long chen School of Mathematics Southeast UniversityNanjing 210096P.R.China

Let R be a unitary ring and a,b∈R with ab=*** find the 2/3 property of Drazin invertibility:if any two of a,b and a+b are Drazin invertible,then so is the third ***,we combine the 2/3 property of Drazin invertibility to characterize the existence of generalized inverses by means of *** applications,the need for two invertible morphisms used by You and chen to characterize the group invertibility of a sum of morphisms is reduced to that for one invertible morphism,and the existence and expression of the inverse along a product of two regular elements are obtained,which generalizes the main result of Mary and Patricio(2016)about the group inverse of a product.

关键词： Leftπ-regular element stronglyπ-regular element group inverse Drazin inverse inverse along an element

Enhanced properties of stone coal-based composite phase change materials for thermal energy storage

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 206-215页

作者： Baoshan Xie Huan Ma Chuanchang Li jian.chen Key Laboratory of Renewable Energy Electric-Technology of Hunan Province School of Energy and Power EngineeringChangsha University of Science and TechnologyChangsha 410114China State Key Laboratory of Disaster Prevention and Reduction for Power Grid Changsha University of Science and TechnologyChangsha 410114China

Phase change materials (PCMs) can be incorporated with low-cost minerals to synthesize composites for thermal energy storage in building *** coal (SC) after vanadium extraction treatment shows potential for secondary utilization in composite *** prepared SC-based composite PCMs with SC as a matrix,stearic acid (SA) as a PCM,and expanded graphite (EG) as an *** combined roasting and acid leaching treatment of raw SC was conducted to understand the effect of vanadium extraction on promoting loading *** showed that the combined treatment of roasting at 900℃ and leaching increased the SC loading of the composite by 6.2%by improving the specific surface *** loading capacity and thermal conductivity of the composite obviously increased by 127%and 48.19%,respectively,due to the contribution of 3wt% *** data were supported by the high load of 66.69%and thermal conductivity of 0.59 W·m^(-1)·K-1of the designed *** obtained composite exhibited a phase change temperature of 52.17℃,melting latent heat of 121.5 J·g^(-1),and good chemical *** SC-based composite has prospects in building applications exploiting the secondary utilization of minerals.

关键词： thermal energy storage phase change material stone coal vanadium extraction secondary utilization

Product quality prediction based on RBF optimized by firefly algorithm

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Journal of Systems Engineering and Electronics 2024年第1期35卷 105-117页

作者： HAN Huihui WANG jian.chen Sen YAN Manting College of Electronics and Information Engineering Tongji UniversityShanghai 201804China

With the development of information technology,a large number of product quality data in the entire manufacturing process is accumulated,but it is not explored and used *** traditional product quality prediction models have many disadvantages,such as high complexity and low *** overcome the above problems,we propose an optimized data equalization method to pre-process dataset and design a simple but effective product quality prediction model:radial basis function model optimized by the firefly algorithm with Levy flight mechanism(RBFFALM).First,the new data equalization method is introduced to pre-process the dataset,which reduces the dimension of the data,removes redundant features,and improves the data *** the RBFFALFM is used to predict product *** expe riments conducted on real-world product quality datasets validate that the new model RBFFALFM combining with the new data pre-processing method outperforms other previous me thods on predicting product quality.

关键词： product quality prediction data pre-processing radial basis function swarm intelligence optimization algorithm

Two-dimensional and absolutely entanglement-breaking subspaces

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Communications in Theoretical Physics 2024年第9期76卷 21-26页

作者： jian.Yan Lin chen LMIB(Beihang University) Ministry of Educationand School of Mathematical SciencesBeihang UniversityBeijing 100191China International Research Institute for Multidisciplinary Science Beihang UniversityBeijing 100191China

Entanglement-breaking(EB)subspaces determine the additivity of entanglement of formation(EOF),which is a long-standing issue in quantum *** explicitly construct the twodimensional EB subspaces of any bipartite system,when system dimensions are equal,and we apply the subspaces to construct EB spaces of arbitrary *** also present partial construction when system dimensions are ***,we present the notion and properties of EB subspaces for some systems,and in particular the absolute EB *** construct some examples of absolute EB subspaces,as well as EB subspaces for some systems by using multiqubit Dicke states.

关键词： entanglement-breaking subspaces entanglement of formation absolutely EB subspaces entanglement cost additivity

Neuronomodulation of Excitable Neurons

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Neuroscience Bulletin 2024年第1期40卷 103-112页

作者： Yizhang chen Lin Xiao jian.Qiu Institute of Neuroscience Second Military Medical UniversityShanghai 200433China Institute for Brain Research and Rehabilitation Key Laboratory of BrainCognition and Education Sciences of Ministry of EducationSouth China Normal UniversityGuangzhou 510631China Department of Chemical Physiology and Biochemistry Oregon Health and Science UniversityPortlandOR 97239USA

Neuronomodulation refers to the modulation of neural conduction and synaptic transmission(i.e.,the conduction process involved in synaptic transmission)of excitable neurons via changes in the membrane potential in response to chemical substances,from spillover neuro-transmitters to paracrine or endocrine hormones circulating in the *** can be direct or indirect,depending on the transduction pathways from the ligand binding site to the ion pore,either on the same molecule,*** ion channel,or through an intermediate step on different *** major players in direct neurono-modulation are ligand-gated or voltage-gated ion *** key process of direct neuronomodulation is the binding and chemoactivation of ligand-gated or voltage-gated ion channels,either orthosterically or allosterically,by various *** neuronomodulation involves metabotropic receptor-mediated slow potentials,where steroid hormones,cytokines,and chemokines can implement these *** neuronomodulation is of great significance for understanding the physiological mechanisms of brain function,and the occurrence and treatment of diseases.

关键词： Neuron Membrane potential Excitability Chemoactivation Neuronomodulation

Control of 2-D Semi-Markov Jump Systems:A View from Mode Generation Mechanism

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 258-260页

作者： Yunzhe Men jian.Sun Jie chen the National Key Laboratory of Autonomous Intelligent Unmanned Systems the School of AutomationBeijing Institute of TechnologyBeijing 100081 the Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China the Department of Control Science and Engineering Tongji UniversityShanghai 201804 the National Key Laboratory of Autonomous Intelligent Unmanned Systems Beijing Institute of TechnologyBeijing 100081China

Dear Editor,Two-dimensional(2-D) systems have wide applications in image data processing,gas absorption and fluid dynamics analysis [1]-[3].When there exist abrupt changes in 2-D systems,they are usually modeled by 2-D Markov jump systems(MJSs) or 2-D semi-Markov jump systems(SMJSs).This letter investigates the control of 2-D SMJSs based on a novel mode generation mechanism,which could avoid mode ambiguousness phenomenon caused by the evolution of system mode in two different *** criterion that guarantees the almost surely exponential stability of the system is obtained.A thermal process is studied to demonstrate the availability of the proposed method.

关键词： Markov mode system