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Stability behavior of the Lanxi ancient flood control levee after reinforcement with upside-down hanging wells and grouting curtain

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Journal of Mountain Science 2024年第1期21卷 84-99页

作者： QIn Zipeng TIAn Yan GAO Siyuan ZHOU Jianfen he Xiaohui he Weizhong GAO Jingquan School of Water conservancy and Environment Engineering Zhejiang University of Water Resources and Electric PowerHangzhou 310018China Department of civil Engineering Imperial College LondonLondonSW71BFEngland Lanxi Water Affairs Bureau Lanxi 321102China Zhejiang Water conservancy Engineering consulting co. LtdHangzhou 310051China

The stability of the ancient flood control levees is mainly influenced by water level fluctuations, groundwater concentration and rainfalls. This paper takes the Lanxi ancient levee as a research object to study the evolution laws of its seepage, displacement and stability before and after reinforcement with the upside-down hanging wells and grouting curtain through numerical simulation methods combined with experiments and observations. The study results indicate that the filled soil is less affected by water level fluctuations and groundwater concentration after reinforcement. A high groundwater level is detrimental to the levee's long-term stability, and the drainage issues need to be fully considered. The deformation of the reinforced levee is effectively controlled since the fill deformation is mainly borne by the upside-down hanging wells. The safety factors of the levee before reinforcement vary significantly with the water level. The minimum value of the safety factors is 0.886 during the water level decreasing period, indicating a very high risk of the instability. While it reached 1.478 after reinforcement, the stability of the ancient levee is improved by a large margin.

关键词： Stability analysis Multiple factors Antiseepage reinforcement Upside-down hanging well Grouting curtain Ancient levee

characterization of a novel Esterase Belonging to Family V from Marinobacter flavimaris

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Journal of Ocean University of china 2024年第1期23卷 221-232页

作者： he Jingjing ZHAnG Yunhui WU Leilei WAnG Yaru ZHAnG he LIU Zhengang SHI Xiaochong Frontiers Science center for Deep Ocean Multispheres and Earth System and College of Marine Life SciencesOcean University of ChinaQingdao 266003China Laboratory for Marine Ecology and Environmental Science Laoshan LaboratoryQingdao 266237China Institute of Evolution&Marine Biodiversity Ocean University of ChinaQingdao 266003China

Lipolytic enzymes have attracted enormous attentions because of their ability in ester hydrolysis,ester synthesis,transesterification and other biochemical *** are important sources of lipolytic enzymes applied in ***,a novel lipolytic enzyme encoded by esterase gene est1347 was identified in Marinobacter flavimaris WLL162,and was purified and *** lipolytic enzyme Est1347 consisted of 312 amino acid residues and a 21-amino-acids n-terminal signal peptide with a predicted molecular weight of 34.2 *** belongs to family V of bacterial lipolytic enzymes based on the amino acid sequence homology ***1347 is a mesophilic and alkali-resistant enzyme with the highest activity at 45℃and pH 8.5;it is stable at temperatures below 50℃and pH 7.5–***1347 showed a preference for middle-length chain substrate p-nPc10 and a wide range of other *** Km,Vmax,Kcat and Kcat/Km values of Est1347 for p-nPc10 in pH 8.5 at 45℃were 0.9411 mmol L^(−1),1285μmol min^(−1)mg^(−1),698.91 s^(−1)and 743.65 s^(−1)(mmol L^(−1))^(−1),*** is also tolerant to the metal ions,organic solvents and *** conclusion,the esterase Est1347 laid a foundation for further study of bacterial lipolytic enzyme family V.

关键词： esterase Marinobacter flavimaris enzymatic properties lipolytic enzyme family V

A Fractional-Order Ultra-Local Model-Based Adaptive neural network Sliding Mode control of n-DOF Upper-Limb Exoskeleton With Input Deadzone

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IEEE/cAA Journal of Automatica Sinica 2024年第3期11卷 760-781页

作者： Dingxin he HaoPing Wang Yang Tian Yida Guo the School of Automation Nanjing University of Science and TechnologyNanjing 210094China IEEE norinco Group Institute of navigation and control Technology Beijing 100089China

This paper proposes an adaptive neural network sliding mode control based on fractional-order ultra-local model for n-DOF upper-limb exoskeleton in presence of uncertainties,external disturbances and input *** the model complexity and input deadzone,a fractional-order ultra-local model is proposed to formulate the original dynamic system for simple controller ***,the control gain of ultra-local model is considered as a *** fractional-order sliding mode technique is designed to stabilize the closed-loop system,while fractional-order time-delay estimation is combined with neural network to estimate the lumped ***,a fractional-order ultra-local model-based neural network sliding mode controller(FO-nnSMc) is ***,to avoid disadvantageous effect of improper gain selection on the control performance,the control gain of ultra-local model is considered as an unknown ***,the nussbaum technique is introduced into the FO-nnSMc to deal with the stability problem with unknown ***,a fractional-order ultra-local model-based adaptive neural network sliding mode controller(FO-AnnSMc) is ***,the stability analysis of the closed-loop system with the proposed method is presented by using the Lyapunov ***,with the co-simulations on virtual prototype of 7-DOF iReHave upper-limb exoskeleton and experiments on 2-DOF upper-limb exoskeleton,the obtained compared results illustrate the effectiveness and superiority of the proposed method.

关键词： Adaptive control input deadzone model-free control n-DOF upper-limb exoskeleton neural network

Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

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Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： he-xiang Wu Jia Qu Lin-zhi Wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

Investigation on the Velocity-Dependent Adhesion Hysteresis via Molecular Dynamics Simulation

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Acta Mechanica Solida Sinica 2024年第3期37卷 423-429页

作者： Jinshan he Yiran Li Zhaoyang Ma Ganyun Huang Department of Mechanics School of Mechanical EngineeringTianjin UniversityTianjin300350China

Adhesion plays an important role in miniaturized devices and technologies,which depends not only on indentation depth but also on the history of contact making and breaking,giving rise to adhesion *** the present work,adhesion hysteresis has been investigated via molecular dynamics simulations on approaching and retracting a rigid tip to and from a *** results show that hysteresis in the force-displacement curve that depends on approaching and retraction velocities arises under both elastic and plastic *** underlying mechanisms have been *** implications of the results in friction have been discussed briefly.

关键词： Adhesion hysteresis Molecular dynamics simulation contact instability Plastic deformation

TGF-βsignaling in health,disease,and therapeutics

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1466-1505页

作者： Ziqin Deng Tao Fan chu Xiao he Tian Yujia Zheng chunxiang Li Jie he Department of Thoracic Surgery National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China

ransforming growth factor(TGF)-βis a multifunctional cytokine expressed by almost every tissue and cell *** signal transduction of TGF-βcan stimulate diverse cellular responses and is particularly critical to embryonic development,wound healing,tissue homeostasis,and immune homeostasis in *** dysfunction of TGF-βcan play key roles in many diseases,and numerous targeted therapies have been developed to rectify its pathogenic *** the past decades,a large number of studies on TGF-βsignaling have been carried out,covering a broad spectrum of topics in health,disease,and ***,a comprehensive overview of TGF-βsignaling is required for a general picture of the studies in this *** this review,we retrace the research history of TGF-βand introduce the molecular mechanisms regarding its biosynthesis,activation,and signal *** also provide deep insights into the functions of TGF-βsignaling in physiological conditions as well as in pathological ***-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are *** the summary of previous knowledge and recent updates,this review aims to provide a systematic understanding of TGF-βsignaling and to attract more attention and interest to this research area.

关键词： homeostasis healing wound

Regulating Melting Process in the Energy Storage of Solid-Liquid PcM based on Double MRT-LBM Simulation

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Journal of Thermal Science 2024年第5期33卷 1688-1700页

作者： chen Weiqi SOnG Zhichao QUAn Dongliang he Yurong School of Energy Science&Engineering Harbin Institute of TechnologyHarbin 150001China heilongjiang Key Laboratory of new Energy Storage Materials and Processes Harbin 150001China Zhengzhou Research Institute of Harbin Institute of Technology Zhengzhou 450000China Innovation&Research Institute of Hiwing Technology Academy Beijing 100074China

The melting process of solid-liquid phase change materials(PcM)has a significant impact on their energy storage *** more effectively apply solid-liquid PcM for energy storage,it is crucial to study the regulation of melting process of solid-liquid PcM,which is numerically investigated based on double multiple relaxation time lattice Boltzmann method(MRT-LBM)in this *** this work we pay more attention to the effects of different Stefan numbers(Ste)and Rayleigh numbers(Ra)on the melting *** results indicate that the PcM melting is greatly influenced by the Ste number and Ra number,which can be divided into the heat conduction dominant stage and the convection dominant stage,according to the onset time of convection Fo_(c).In order to describe the contribution of the heat conduction dominant stage to the whole melting process quantitatively,we firstly propose the ratio of the heat conduction dominant stage R_(pc),which can be defined as the ratio of Fo_(c)to the complete melting time Fo_(M).R_(pc)gradually decreases as the Ra number increases,and when the Ste number rises:R_(pc)=90.0%when Ste=1.0 and Ra=1×10^(5),R_(pc)=39.6%when Ste=0.1 and Ra=1×10^(5),and R_(pc)=14.0%when Ste=1.0 and Ra=1×10~7.A regime map about the effects of different Ste numbers and Ra numbers on R_(pc)has been further *** discovered findings would be helpful in regulating melting process in the energy storage of solid-liquid PcM.

关键词： latent thermal energy storage solid-liquid phase change double MRT-LBM dominant melting mechanism

non-convex optimization for inverse problem solving in computer-generated holography

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Light(Science & Applications) 2024年第8期13卷 1464-1486页

作者： Xiaomeng Sui Zehao he Daping chu Liangcai cao Department of Precision Instruments Tsinghua UniversityBeijing 100084China Department of Engineering Centre for Photonic Devices and SensorsUniversity of Cambridge9 JJ Thomson AvenueCambridge CB30FAUK cambridge University nanjing centre of Technology and Innovation 23 Rongyue RoadJiangbei New AreaNanjing 210000China

computer-generated holography is a promising technique that modulates user-defined wavefronts with digital *** appropriate holograms with faithful reconstructions is not only a problem closely related to the fundamental basis of holography but also a long-standing challenge for researchers in general fields of *** the exact solution of a desired hologram to reconstruct an accurate target object constitutes an ill-posed inverse *** general practice of single-diffraction computation for synthesizing holograms can only provide an approximate answer,which is subject to limitations in numerical *** non-convex optimization algorithms are thus designed to seek an optimal solution by introducing different constraints,frameworks,and ***,we overview the optimization algorithms applied to computer-generated holography,incorporating principles of hologram synthesis based on alternative projections and gradient descent *** is aimed to provide an underlying basis for optimized hologram generation,as well as insights into the cuttingedge developments of this rapidly evolving field for potential applications in virtual reality,augmented reality,head-up display,data encryption,laser fabrication,and metasurface design.

关键词： optimization convex inverse

Improved Subsynchronous Oscillation Parameter Identification with Synchrophasor Based on Matrix Pencil Method in Power Systems

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Journal of Modern Power Systems and clean Energy 2024年第1期12卷 22-33页

作者： Xiaoxue Zhang Fang Zhang Wenzhong Gao Jinghan he the School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China the Department of Electrical and computer Engineering University of DenverDenverUSA

The subsynchronous oscillations(SSOs)related to renewable generation seriously affect the stability and safety of the power *** realize the dynamic monitoring of SSOs by utilizing the high computational efficiency and noise-resilient features of the matrix pencil method(MPM),this paper propos es an improved MPM-based parameter identification with syn *** MPM is enhanced by the angular frequency fitting equations based on the characteristic polynomial coeffi cients of the matrix pencil to ensure the accuracy of the identi fied parameters,since the existing eigenvalue solution of the MPM ignores the angular frequency conjugation constraints of the two fundamental modes and two oscillation ***,the identification and recovery of bad data are proposed by uti lizing the difference in temporal continuity of the synchropha sors before and after noise *** proposed parameter identification is verified with synthetic,simulated,and actual measured phase measurement unit(PMU)*** with the existing MPM,the improved MPM achieves better accuracy for parameter identification of each component in SSOs,better real-time performance,and significantly reduces the effect of bad data.

关键词： Subsynchronous oscillations(SSOs) synchrophasor parameter identification matrix pencil method bad data