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Effect of Wave Nonlinearity on the Instantaneous Seabed Liquefaction

China Ocean Engineering 2024年第1期38卷 93-103页

作者： WANG Zhao-jun SUI Ti-ti zhang Chi PAN jun-ning Key Laboratory of Port Waterway and Sedimentation Engineering of the Ministry of TransportNanjing Hydraulic Research InstituteNanjing 210024China Key Laboratory of Coastal Disaster and Protection(Hohai University) Ministry of EducationNanjing 210098China The National Key Laboratory of Water Disaster Prevention Nanjing 210098China

The nonlinear variation of wave is commonly seen in nearshore area,and the resulting seabed response and liquefaction are of high concern to coastal *** this study,an analytical formula considering the nonlinear wave skewness and asymmetry is adopted to provide wave pressure on the seabed *** liquefaction depth attenuation coefficient and width growth coefficient are defined to quantitatively characterize the nonlinear effect of wave on seabed *** on the 2D full dynamic model of wave-induced seabed response,a detailed parametric study is carried out in order to evaluate the influence of the nonlinear variation of wave loadings on seabed ***,new empirical prediction formulas are proposed to fast predict the maximum liquefaction under nonlinear *** indicate that(1)Due to the influence of wave nonlinearity,the vertical transmission of negative pore water pressure in the seabed is hindered,and therefore,the amplitude decreases significantly.(2)In general,with the increase of wave nonlinearity,the liquefaction depth of seabed decreases *** under asymmetric and skewed wave loading,the attenuation of maximum seabed liquefaction depth is the most significant among all the nonlinear wave ***,highly skewed wave can cause the liquefaction depth of seabed greater than that under linear wave.(3)The asymmetry of wave pressure leads to the increase of liquefaction width,whereas the influence of skewedness is not significant.(4)Compared with the nonlinear waveform,seabed liquefaction is more sensitive to the variation of nonlinear degree of wave loading.

关键词： nonlinear wave seabed response seabed liquefaction numerical simulation liquefaction prediction

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Unveiling evapotranspiration patterns and energy balance in a subalpine forest of the Qinghai-Tibet Plateau:observations and analysis from an eddy covariance system

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Journal of Forestry Research 2024年第3期35卷 175-188页

作者： Niu Zhu Jinniu Wang Dongliang Luo Xufeng Wang Cheng Shen ning Wu ning zhang Binghui Tian Aihong Gai Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041People's Republic of China College of Resources and Environmental Sciences Gansu Agricultural UniversityLanzhou 730070People's Republic of China Mangkang Ecological Monitoring Station Tibet Ecological Security Barrier Ecological Monitoring NetworkQamdo 854500People's Republic of China Northwest Institute of Eco Environmental Resources Chinese Academy of SciencesLanzhou 730000People's Republic of China

Evapotranspiration is an important parameter used to characterize the water cycle of *** under-stand the properties of the evapotranspiration and energy balance of a subalpine forest in the southeastern Qinghai-Tibet Plateau,an open-path eddy covariance system was set up to monitor the forest from November 2020 to October 2021 in a core area of the Three Parallel Rivers in the Qing-hai-Tibet *** results show that the evapotranspira-tion peaked daily,the maximum occurring between 11:00 and 15:*** factors had significant effects on evapotranspiration,among them,net radiation the greatest(R^(2)=0.487),and relative humidity the least(R^(2)=0.001).The energy flux varied considerably in different seasons and sensible heat flux accounted for the main part of turbulent *** energy balance ratio in the dormant season was less than that in the growing season,and there is an energy imbalance at the site on an annual time scale.

关键词： Evapotranspiration Energy balance Subalpine forest Three Parallel Rivers region Southeast Qinghai-Tibet Plateau

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An Improved Modulation Strategy for Single-phase Three-level Neutral-point-clamped Converter in Critical Conduction Mode

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 981-990页

作者： ning Li Yujie Cao Xiaokang Liu Yan zhang Ruotong Wang Lin Jiang Xiao-Ping zhang School of Electrical Engineering Xi’an University of TechnologyXi’anChina the Department of Electronics Information and BioengineeringPolitecnico di MilanoMilanItaly Xi’an Jiaotong University Xi’anChina the Department of Electrical Engineering and Electronics University of LiverpoolLiverpoolU.K. the Department of Electronic Electrical and Systems EngineeringUniversity of BirminghamBirminghamU.K.

Two-level totem-pole power factor correction(PFC)converters in critical conduction mode(CRM)suffer from the wide regulation range of switching ***,in highfrequency applications,the number of switching times increases,resulting in significant switching *** solve these issues,this paper proposes an improved modulation strategy for the single-phase three-level neutral-point-clamped(NPC)converter in CRM with *** optimizing the discharging strategy and switching state sequence,the switching frequency and its variation range have been efficiently *** detailed performance analysis is also presented regarding the switching frequency,the average switching times,and the effect of voltage gain.A 2 k W prototype is built to verify the effectiveness of the proposed modulation strategy and analysis *** with the totem-pole PFC converter,the switching frequency regulation range of the three-level PFC converter is reduced by 36.48%and the average switching times is reduced by 45.10%.The experimental result also shows a 1.2%higher efficiency for the three-level PFC converter in the full load range.

关键词： Critical conduction mode(CRM) on-board charger switching frequency range switching times power factor correction(PFC) three-level converter

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Reinforcement Learning-Based MAS Interception in Antagonistic Environments

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 270-272页

作者： Siqing Sun Defu Cai Hai-Tao zhang ning Xing the School of Artificial Intelligence and Automation the MOE Engineering Research Center of Autonomous Intelligent Unmanned Systemsthe Guangdong Engineering Technology Research Center of Fully Autonomous Unmanned Surface VehiclesHuazhong University of Science and TechnologyWuhan 430074China the State Grid Hubei Electric Power Research Institute Wuhan 430074China IEEE

Dear Editor, As a promising multi-agent systems(MASs) operation, autonomous interception has attracted more and more attentions in these years, where defenders prevent intruders from reaching *** far, most of the relevant methods are applied in ideal environments without agent damages. As a remedy, this letter proposes a more realistic interception method for MASs suffered by damages.

关键词： agent MAS destination

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Weight Analysis of Impact Factors of Interbedded Anti-Inclined Slopes Block-Flexure Toppling Based on Support Vector Regression

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Journal of Earth Science 2024年第2期35卷 568-582页

作者： Bocheng zhang Huiming Tang Yibing ning Kun Fang Ding Xia Department of Engineering Geology and Geotechnical Engineering Faculty of EngineeringChina University of GeosciencesWuhan430074China Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan430074China College of Geological Engineering and Geomatics Chang’an UniversityXi’an710054China

Block-flexure toppling failure is frequently encountered in interbedded anti-inclined rock(IAR)slopes,and seriously threatens the construction of hydropower *** this study,we first investigated the Lean Reservoir area’s geological setting and the Linda landslide’s ***,uniform design and random design were used to design 110 training datasets and 31 testing datasets,***,the toppling response was obtained by using the discrete element ***,support vector regression was used to obtain the influence weights of 21 impact *** results show that the influence weight of the slope angle and rock formation dip angle on the toppling deformation among tertiary impact factors is 25.96%and 17.28%,respectively,which are much greater than the other 19 impact factors within the research *** the primary impact factors,the influence weight is sorted from large to small as slope geometry parameters,joints parameters,and rock mechanics *** parameters,especially the geometric parameters,cannot be ignored when evaluating the stability of IAR *** numerical simulation,it was qualitatively determined that failure surfaces of slopes were controlled by cross joints and that the rocks in the slope toe play a role in preventing slope deformation.

关键词： interbedded anti-inclined slopes block-flexure toppling impact factors numerical simulation support vector regression engineering geology

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Extraction of Acoustic Normal Mode Depth Functions Using Range-Difference Method with Vertical Linear Array Data

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Journal of Ocean University of China 2024年第4期23卷 871-882页

作者： GAO Siyu LI Weilu zhang Yinquan LI Xiaolei WANG ning College of Marine Technology Ocean University of ChinaQingdao 266100China National Marine Data and Information Service Tianjin 300171China

Data-derived normal mode extraction is an effective method for extracting normal mode depth functions in the absence of marine environmental ***,when the corresponding singular vectors become nonunique when two or more singular values obtained from the cross-spectral density matrix diagonalization are nearly equal,this results in unsatisfactory extraction outcomes for the normal mode depth *** address this issue,we introduced in this paper a range-difference singular value decomposition method for the extraction of normal mode depth *** performed the mode extraction by conducting singular value decomposition on the individual frequency components of the signal's cross-spectral density *** was achieved by using pressure and its range-difference matrices constructed from vertical line array *** proposed method was validated using simulated *** addition,modes were successfully extracted from ambient noise.

关键词： range difference depth function extraction normal mode

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Ballistic performance of spherical fragments penetrating PCrNi3MoV target plates

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Defence Technology（防务技术） 2024年第3期33卷 295-307页

作者： Dou Hong Wenbin Li Yu Zheng Yiming Li ning Jiang Kebin zhang Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjingChina

PCrNi3MoV steel is a medium-carbon,low-alloy quenched and tempered steel that finds its applications in military gun barrels due to the high wear resistance and ablation *** study the penetration and failure modes of PCrNi3MoV plates impacted by tungsten spheres,tungsten spheres of various diameters(5 mm,8 mm,and 10 mm)were used to impact PCrNi3MoV steel plates with thicknesses of 6 mm,9 mm,and 14 *** penetration performance of the spheres was analyzed for different velocities,and the ultimate penetration velocity of the plate was *** was found that the primary failure modes of the PCrNi3MoV plate were compression pitting failure and shear *** the dimensional analysis method,a relationship between the bulge height of the steel plate and the fragment velocity,an equation for the ultimate penetration velocity,and a relationship between the target penetration energy and the fragment velocity were ***,a projectile-target action index was proposed to describe the process of tungsten spheres with different velocities impacting target *** results suggested that under the same thickness of the target plate,a larger-diameter fragment required more kinetic energy to obtain the same ultimate penetration effect as a smaller-diameter *** equations obtained through dimensional analysis predicted values that agreed well with experimental values,indicating that these equations can be applied to engineering applications.

关键词： Impact damage Ultimate penetration velocity Bulge height Target penetration energy Failure modes

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Communication Resources Allocation for Time Delay Reduction of Frequency Regulation Service in High Renewable Penetrated Power System

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 468-480页

作者： Hongjie He ning zhang Chongqing Kang Song Ci Fei Teng Goran Strbac State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Department of Electrical and Electronic Engineering Imperial College LondonSW72BULondonU.K

The high renewable penetrated power system has severe frequency regulation *** resources can provide frequency regulation services but are limited by com-munication time *** paper proposes a communication resources allocation model to reduce communication time delay in frequency regulation *** device resources and wireless spectrum resources are allocated to distributed resources when they participate in frequency *** reveal impact of communication resources allocation on time delay reduction and frequency regulation ***,we study communication resources allocation solution in high renewable energy penetrated power *** provide a case study based on the HRP-38 *** show communication time delay decreases distributed resources'ability to provide frequency regulation *** the other hand,allocating more communication resources to distributed resources'communica-tion services improves their frequency regulation *** power systems with renewable energy penetration above 70%,required communications resources are about five times as many as 30%renewable energy penetrated power systems to keep frequency performance the *** Terms-Communication resources allocation,commun-ication time delay,distributed resource,frequency regulation,high renewable energy penetrated power system.

关键词： Communication resources allocation communication time delay distributed resource frequency regulation high renewable energy penetrated power system

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A comprehensive comparison of different regression techniques and nature-inspired optimization algorithms to predict carbonation depth of recycled aggregate concrete

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 30-50页

作者： Bin XI ning zhang Enming LI Jiabin LI Jian ZHOU Pablo SEGARRA Department of Civil and Environmental Engineering Politecnico Di MilanoMilano 20133Italy Leibniz Institute of Ecological Urban and Regional Development(IOER) Dresden 01217Germany Universidad Politécnica de Madrid-ETSI Minas y Energía Madrid 28003Spain Department of Civil Engineering KU Leuven CampusBrugge 8200Belgium School of Resources and Safety Engineering Central South UniversityChangsha 410083China

The utilization of recycled aggregates(RA)for concrete production has the potential to offer substantial environmental and economic ***,RA concrete is plagued with considerable durability concerns,particularly *** advance the application of RA concrete,the establishment of a reliable model for predicting the carbonation is *** the one hand,concrete carbonation is a long and slow process and thus consumes a lot of time and energy to *** the other hand,carbonation is influenced by many factors and is hard to *** this,this paper proposes the use of machine learning techniques to establish accurate prediction models for the carbonation depth(CD)of RA *** types of regression techniques and meta-heuristic algorithms were employed to provide more alternative predictive *** was found that the best prediction performance was obtained from extreme gradient boosting-multi-universe optimizer(XGB-MVO)with R^(2) value of 0.9949 and 0.9398 for training and testing sets,***-MVO was used for evaluating physical laws of carbonation and it was found that the developed XGB-MVO model could provide reasonable predictions when new data were *** also showed better generalization capabilities when compared with different models in the ***,this paper emphasizes the need for sustainable solutions in the construction industry to reduce its environmental impact and contribute to sustainable and low-carbon economies.

关键词： recycled aggregate concrete carbonation depth nature-inspired optimization algorithms extreme gradient boosting technique parametric analysis

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pH Induced Self-assembly of AIE Fluorescent Probe for Tumor Imaging

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Chinese Journal of Polymer Science 2024年第1期42卷 7-13,I0005页

作者： Jing-Yuan Xiang Wen-Long zhang He-Ting Li Ya-ning He Department of Chemical Engineering Key Laboratory of Advanced Materials(MOE)Tsinghua UniversityBejing 100084China

This work reported an AIE fluorescent probe for tumor imaging based on the p H induced self-assembly strategy. The fluorescent probe was composed of an acid-responsive soluble copolymer PEG-b-PAMA-DMMA with a maleic acid amide group and an anionic soluble aggregation-induced emission fluorogen(AIEgen) TPE-2SO_(3)^(-). The polymer could be transformed into a protonated amine-containing polymer after the hydrolysis of maleic acid amide in acidic tumor microenvironment, which would be further self-assembled with TPE-2SO_(3)^(-)to form aggregated nanoparticles. The transition of TPE-2SO_(3)^(-)from dispersed state to aggregated state led to an obvious increase in fluorescence intensity due to its AIE characteristics.

关键词： p H-responsive Self-assembly Fluorescent probe AIE Tumor imaging

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