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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 677-690页

作者： Huang Huan Li Yingxiong Li Yuyu College of water conservancy and Civil Engineering South China Agricultural UniversityGuangzhou 510642China inst.tute of Smart City and Intelligent Transportation Southwest Jiaotong UniversityChengdu 611756China

An efficient approach is proposed for the equivalent linearization of frame structures.with plastic hinges under nonstationary seismic *** concentrated plastic hinges,described by the Bouc-Wen model,are assumed to occur at the two ends of a linear-elastic beam *** auxiliary differential equations governing the plastic rotational displacements and their corres.onding hysteretic displacements are replaced with linearized differential ***,the two sets of equations of motion for the original nonlinear system can be reduced to an expanded-order equivalent linearized equation of motion for equivalent linear *** solve the equation of motion for equivalent linear systems,the nonstationary random vibration analysis is carried out based on the explicit time-domain method with high ***,the proposed treatment method for initial values of equivalent parameters is investigated in conjunction with parallel computing technology,which provides a new way of obtaining the equivalent linear systems at different time *** on the explicit time-domain method,the key res.onses of interes. of the converged equivalent linear system can be calculated through dimension reduction analysis with high *** examples indicate that the proposed approach has high computational efficiency,and shows good applicability to weak nonlinear and medium-intensity nonlinear systems.

关键词： nonstationary random vibration plastic hinge equivalent linearization method explicit time-domain method parallel computation

Numerical study of submerged bending vegetation under unidirectional flow

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water Science and Engineering 2024年第1期17卷 92-100页

作者： Pei-pei Zhang Yi-qing Gong Ken Vui Chua Jie Dai Jing-qiao Mao College of water conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China inst.tute of water Science and Technology Hohai UniversityNanjing 210098China School of Engineering Cardiff UniversityCardiff CF243AAUK

Submerged vegetation commonly grows and plays a vital role in aquatic ecosystems,but it is also regarded as a barrier to the passing *** simulations of flow through and over submerged vegetation were carried out to investigate the effect of vegetation density on flow *** simulations were computationally set up to replicate flume experiments,in which vegetation was mimicked with flexible plastic *** fluid-structure interaction between flow and flexible vegetation was solved by coupling the two modules of the COMSOL *** cases with different vegetation densities were simulated,and the res.lts were successfully validated against.the experimental *** contours of the simulated time-averaged streamwise velocity and Reynolds stres. were extracted to highlight the differences in mean and turbulent flow *** turbulence intensity was found to be more sensitive to vegetation density than the time-averaged *** developing length increased with the spacing between *** snapshots of the bending vegetation under inst.ntaneous velocity and vorticity revealed that flexible vegetation res.onded to the effects of eddies in the shear layer by swaying *** first two rows of vegetation suffered stronger approaching flow and were prone to more streamlined *** addition,the origin of tip vortices was investigated via the distribution of *** res.lts reveal the variation of flow properties with bending submerged vegetation and provide useful reference for optimizationofres.orationprojects.

关键词： Computational fluid dynamics Fluid-structure interaction Turbulence Flexible and submerged vegetation

Biochar regulates biogeochemical cycling of iron and chromium in a soil-rice system by stimulating Geobacter and Clostridium

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Pedosphere 2024年第5期34卷 929-940页

作者： Min XU Yang LIN Jing MA Lulu LONG Chao CHEN Gang YANG Chun SONG Jun WU Xiaohong ZHANG Peng GAO College of Environmental Science Sichuan Agricultural University Soil Water and Ecosystem Sciences Department University of Florida College of water conservancy and Hydropower Engineering Sichuan Agricultural University Department of Environmental and Occupational Health University of Pittsburgh School of Public Health

In soil-rice systems,microbial reduction of iron （Fe） has been recognized as a crucial biogeochemical process that regulates Fe and chromium （Cr）translocation;however,the underlying processes are *** investigate the impacts of biochar on the biochemical cycling of Fe and Cr and their toxicity to rice,maize straw biochar was applied at 1%（weight/weight） to a paddy soil spiked with 300 mg kg-1Cr under two phosphorus （P） levels (0 or 90 mg kg-1) in a pot *** key microbial groups affecting Fe dissimilatory reduction and their environmental drivers were *** inhibited root Cr uptake by 36%,owing to the promoted iron plaque （IP） formation on the rice root *** analysis showed that Fe concentration in pore water was strongly linked to the abundances of Geobacter （r=0.81–0.94,Pwater P concentrations were the key determinants influencing Fe-reducing bacterial abundances,accounting for 42%and 32%of the variation in community composition,***,biochar increased Fe and P concentrations in root cell walls,which retained more ***,Cr stres. in rice under biochar treatment was relieved through increasing IP formation and altering subcellular *** mechanistic insights had important implications for reducing Cr uptake by rice.

关键词： chromium translocation iron plaque iron reduction maize straw biochar microbial reduction paddy soil phosphorus fertilization subcellular distribution

Creep damage evolution process of asphalt binder based on viscoelastic characteristics

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 497-506页

作者： Xiaofei Qi Shuang Tian Liyan Shan Shuang Liu Yajie Wang School of Transportation Science and Engineering Harbin Institute of TechnologyHarbin 150090China College of water conservancy&Architectural Engineering Shihezi UniversityShihezi 832003China

The creep damage evolution of asphalt binder plays a significant role in investigating the formation mechanism of *** rutting is the common distres. at high temperatures.for asphalt ***,the reliability of existing creep damage parameters is under questioned,and these parameters cannot accurately illustrate the change of intrinsic microstructure for asphalt *** this paper,a new test protocol was given access to study the evolution of viscoelastic parameters during creep *** was completed by inserting the frequency sweep during creep *** frequency sweep curve clusters were fitted by the generalized Kelvin-Voigt model for obtaining the change law of model *** on the change law and sensitivity analysis of model parameters,(E_(2)+E_(3))/2 was proposed as the creep damage *** to the curve of(E_(2)+E_(3))/2 versus loading time,two stages during the creep test could be identified:an approximate constant value in phase I and a linear decrease in phase *** differences about creep property of binders could be determined by this new proposed *** res.lts not only ensure better understanding of the creep damage mechanism of binders,but also lay the theoretical foundation on predicting the anti-rutting performance of binders.

关键词： Asphalt binder Multi-stage creep test Damage variable Evolution law

What control the spatial patterns and predictions of runoff res.onse over the contiguous USA?

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Journal of Geographical Sciences 2024年第7期34卷 1297-1322页

作者： JIANG Shanhu DU Shuping REN Liliang GONG Xinglong YAN Denghua YUAN Shanshui LIU Yi YANG Xiaoli XU Chongyu The National Key Laboratory of water Disaster Prevention Hohai UniversityNanjing210098China College of Hydrology and water res.urces Hohai UniversityNanjing210098China School of water conservancy&Civil Engineering Northeast Agricultural UniversityHarbin150030China Department of water res.urces China Institute of Water Resources and Hydropower ResearchBeijing100038China Department of Geosciences University of OsloOsloNorway

Understanding the nonlinear relationship between hydrological res.onse and key factors and the cause behind this relationship is vital for water res.urce management and earth system *** this study,we undertook several steps to explore the ***,we partitioned runoff res.onse change(RRC)into multiple components associated with climate and catchment properties,and examined the spatial patterns and smoothness indicated by the Moran's Index of RRC across the contiguous United States(CONUS).Subsequently,we employed a machine learning model to predict RRC using catchment attribute predictors encompassing climate,topography,hydrology,soil,land use/cover,and ***,we identified the primary factors influencing RRC and quantified how these key factors control RRC by employing the accumulated local effect,which allows for the repres.ntation of not only dominant but also secondary ***,we explored the relationship between ecoregion patterns,climate gradients,and the distribution of RRC across *** findings indicate that:(1)RRC demonstrating significant connections between catchments tends to be well predicted by catchment attributes in space;(2)climate,hydrology,and topography emerge as the top three key attributes nonlinearly influencing the RRC patterns,with their second-order effects determining the heterogeneous patterns of RRC;and(3)local Moran's I signifies a collaborative relationship between the patterns of RRC and their spatial smoothness,climate space,and ecoregions.

关键词： hydrological res.onse prediction machine learning accumulated local effect Moran’s Index large-sample study

Optimization Study of Active-Passive Heating System Parameters in Village Houses in the Southern Xinjiang Province

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Energy Engineering 2024年第7期121卷 1963-1990页

作者： Xiaodan Wu Jie Li Yongbin Cai Sihui Huang College of water conservancy&Architectural Engineering Shihezi UniversityShihezi823000China Scientific res.arch Department Shihezi UniversityShihezi823000China

Aiming at the problems of large energy consumption and serious pollution of winter heating existing in the rural buildings in Southern Xinjiang,a combined active-passive heating system was proposed,and the simulation software was used to optimize the parameters of the system,according to the parameters obtained from the optimization,a test platform was built and winter heating test was carried *** simulation res.lts showed that the thickness of the air layer of 75 mm,the total area of the vent holes of 0.24 m^(2),and the thickness of the insulation layer of 120 mm were the optimal construction for the passive part;solar collector area of 28 m^(2),hot water storage tank volume of 1.4 m^(3),mass flow rate of 800 kg/h on the collector side,mass flow rate of 400 kg/h on the heat exchanger side,and output power of auxiliary heat source of 5∼9 kWwere the optimal constructions for active heating *** res.lts showed that during the heating period,the system could provide sufficient heat to the room under different heating modes,and the indoor temperature reached over 18°C,which met the heating *** economic and environmental benefits of the system were analyzed,and the economic benefits of the systemwere better than coal-fired heating,and the CO_(2) emissionswere reduced by 3,292.25 kg compared with *** res.lts of the study showed that the combinedactive-passiveheating systemcouldeffectively solve the heating problems existing in rural buildings in Southern Xinjiang,and it also laid the theoretical foundation for the popularization of the combined heating systems.

关键词： Trombe wall biomass boilers active-passive combined heating systems parameter optimization villages and towns

Characteristics and influencing factors of greenhouse gas emissions from res.rvoirs in the Yellow River Basin:A Meta-analysis

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Science China Earth Sciences 2024年第7期67卷 2210-2225页

作者： Shurui HUANG Peijia ZHANG Wenxiu ZHENG Jiajia ZHANG Yang LI Yuanjian WANG Enhui JIANG Shaoda LIU Xinghui XIA State Key Laboratory of water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 00875China Yellow River inst.tute of Hydraulic res.arch Yellow River Conservancy CommissionZhengzhou 450003China

res.rvoir construction and operation profoundly alter the hydrological,hydrodynamic,and carbon and nitrogen cycling processes of ***,current res.arch still lacks a systematic understanding of the characteristics of greenhouse gas(GHG)emissions from res.rvoirs in arid/semi-arid *** study integrates existing monitoring data to discuss the characteristics of GHG emissions from res.rvoirs in the Yellow River Basin and illustrate the controlling factors and underlying mechanism of these *** res.lts indicate that while CO_(2) emission flux from res.rvoirs is lower than that from river channels,the emission fluxes of CH_(4) and N_(2)O are 1.9 times and 10 times those from rivers,res.ectively,indicating that the emission of GHG with stronger radiative effect is significantly enhanced in *** to the res.rvoirs in humid climates(e.g.,the Three Gorges res.rvoir),res.rvoirs in the Yellow River Basin exhibit relatively lower emissions of CO_(2) and CH_4 due to lower organic matter concentrations,but significantly higher N_(2)O emissions due to higher nitrogen *** Carlo simulations for 237 res.rvoirs in the Yellow River Basin showed that total emission of the three GHGs is 3.05 Tg CO_(2)-eq yr^(-1),accounting for 0.39% of the total emission from global res.rvoirs and lower than the area percentage of the basin(0.53%).This study has important implications on revealing the GHG emission characteristics and control mechanisms of res.rvoirs in arid/semi-arid regions.

关键词： Yellow River Basin res.rvoir Greenhouse gas Emission flux water quality

Numerical simulation of transient characteristics in a bulb turbine during the load rejection process

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Journal of Hydrodynamics 2024年第1期36卷 170-183页

作者： Yue Lu Yu-quan Zhang Zhong-wei He Yuan Zheng College of water conservancy and Hydropower Engineering Hohai UniversityNanjing210098China College of Energy and Electrical Engineering Hohai UniversityNanjing210098China Huadong Engineering Corporation Ltd. Hangzhou311122China

To evaluate the safety of the bulb tubular turbine,the dynamic hydraulic characteristics of a hydropower station system during the load rejection process are studied through numerical simulations and a prototype *** the developed model,a dynamic grid technology(DGT)controls the closure of the guide vane and the blade,whilst the moment balance equation and the user-defined function(UDF)provide the runner’s rotation *** 3-D transient simulation method can well predict the rotation speed and mass flow curves in the state of load *** simulation outcomes of the system performance are basically consistent with the measurement data of the *** observed,the runner is subjected to the reversely increased torque and axial force,the system is in a braking phase,and the maximum speed peaks at 144.6%of the rated ***,the internal flow of the runner is greatly affected by the closure of the guide vane,and the draft tube forms an eccentric spiral vortex *** breaks downstream,aggravating the inst.bility of the draft ***,the transient characteristics span for the first five seconds,demonstrating the importance of establishing an efficient governing *** obtained res.lts are useful for designing the turbine’s flow channel with a double regulating function and comprehending the turbine’s transient characteristics.

关键词： Bulb tubular turbine load rejection numerical simulation dynamic grid prototype test

Numerical Simulation-Based Analysis of the Impact of Overloading on Segmentally Assembled Bridges

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Structural Durability & Health Monitoring 2024年第5期18卷 663-681页

作者： Donghui Ma Wenqi Wu Yuan Li Lun Zhao Yingchun Cai Pan Guo Shaolin Yang Shanghai Urban Construction and Maintenance Management Co. Ltd.Shanghai200023China School of water conservancy and Transportation Zhengzhou UniversityZhengzhou450001China

Segmentally assembled bridges are increasinglyﬁnding engineering applications in recent years due to their unique advantages,especially as urban *** loads are one of the most important variable loads acting on bridge ***,the inﬂuence of overloaded vehicles on existing assembled bridge structures.is an urgent concern at *** paper establishes theﬁnite element model of the segmentally assembled bridge based on ABAQUS software and analyzes the inﬂuence of vehicle overload on an assembled girder bridge ***,aﬁnite element model corres.onding to the target bridge is established based on ABAQUS software,and the load is controlled to simulate vehicle movement in each area of the traveling zone at different ***-ond,the key cross-sections of segmental girder bridges are monitored in real time based on the force character-istics of continuous girder bridges,and they are compared with the simulation ***,a material damage ontology model is introduced,and the structural damage caused by different overloading rates is compared and *** show that theﬁnite element modeling method is accurate by comparing with on-site measured data,and it is suitable for the numerical simulation of segmental girder bridges;Dynamic sensors inst.lled at 1/4L,1/2L,and 3/4L of the segmental girder main beams could be used to identify the dynamic res.onse of segmental girder bridges;The bottom plate of the segmental girder bridge is mostly damaged at the position where the length of the precast beam section changes and the midspan *** the increase in load,damage in the direction of the bridge develops faster than that in the direction of the transverse ***ﬁndings of this study can guide maintenance departments in the management and maintenance of bridges and vehicles.

关键词： Segmentally assembled bridge dynamic res.onse moving loads overloading structural damage ﬁnite element analysis

Advancement of metal(loid)res.arch on farmland

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Frontiers of Agricultural Science and Engineering 2024年第3期11卷 442-467页

作者： Qiang ZHENG Chenchen WEI Yanbing CHI Peiling YANG College of water res.urces and Civil Engineering China Agricultural UniversityBeijing 100083China Agricultural water conservancy Department Changjiang River Scientific Research InstituteWuhan 430019China Zhejiang University of water res.urces and Electric Power Hangzhou 310018China

Metal(loid)pollution has emerged as a pres.ing environmental issue in agriculture,garnering extensive public ***(loid)s are potentially toxic substances that infiltrate the soil through diverse pathways,leading to food chain contamination via plant uptake and subsequent animal *** poses a serious threat to environmental quality,food security,and human ***,the remediation of metal(loid)-contaminated agricultural soil is an urgent concern demanding immediate ***,the majority of res.arch papers concentrate on established,isolated remediation technologies,often overlooking comprehensive field management *** is imperative to provide a comprehensive summary of remediation technologies and identify future development *** review aims to comprehensively summarize a range of soil remediation and enhancement technologies,incorporating insights from multiple disciplines including physics,chemistry,biology,and their interdisciplinary *** review examines the mechanisms of action,suitable scenarios,advantages,disadvantages,and benefits associated with each remediation *** relevant is the examination of metal(loid)sources,as well as the mechanisms behind both established and innovative,efficient remediation and enhancement ***,the future evolution of remediation technologies are considered with the aim of offering a scientific res.arch foundation and inspiration to fellow *** is intended to facilitate the advancement of remediation technologies and establish a robust foundation for sustainable development of soil.

关键词： Metal(loid)pollution metal(loid)remediation metal(loid)sources soil