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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 51-63页

作者： Li Zhenya Pan Yunchao He Xianbin Lv Chong Mohammad Towhid Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing 210098China Geotechnical research institute Hohai UniversityNanjing 210098China MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou 310058China

This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction ***,the pile-soil system is partitioned into finite segments in the vertical direction and the Voigt model is applied to simulate the vertical support of the surrounding soil acting on the pile *** surrounding soil is divided into finite ring-shaped zones in the radial direction to consider the construction ***,the shear complex stiffness at the pile-soil interface is derived by solving the dynamic equilibrium equation for the soil from the outermost to innermost *** displacement impedance at the top of an arbitrary pile segment is obtained by solving the dynamic equilibrium equation for the pile and is combined with the vertical support of the surrounding soil to derive the displacement impedance at the bottom of the upper adjacent ***,the displacement impedance at the pile head is obtained based on the impedance function transfer ***,the reliability of the proposed solution is verified,followed by a sensitivity analysis concerning the coupling effect of the pile parameters,construction disturbance and the vertical support of the surrounding soil on the displacement impedance of the pile.

关键词： tapered pipe pile longitudinal vibration vertical support of the surrounding soil construction disturbance displacement impedance

Sample Generation for Security Region Boundary Identification Based on Topological Features of Historical Operation Data

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1087-1095页

作者： Xiaokang Wu Wei Xu Feng Xue College of Energy and Electrical Engineering Hohai UniversityNanjingChina NARI Group Corporation NanjingChina State Grid Electric Power research institute NanjingChina

Since the scale and uncertainty of the power sys-tem have been rapidly increasing,the computation efficiency of constructing the security region boundary(SRB)has become a prominent *** on the topological features of histori-cal operation data,a sample generation method for SRB identi-fication is proposed to generate evenly distributed samples,which cover dominant security *** boundary sample pair(BSP)composed of a secure sample and an unsecure sam-ple is defined to describe the feature of *** resolution,sampling,and span indices are designed to evaluate the cover-age degree of existing BSPs on the SRB and generate samples closer to the *** on the feature of flat distribution of BSPs over the SRB,the principal component analysis(PCA)is adopted to calculate the tangent vectors and normal vectors of ***,the sample distribution can be expanded along the tangent vector and corrected along the normal vector to cover different security ***,a sample set is randomly gen-erated based on the IEEE standard example and another new sample set is generated by the proposed *** results in-dicate that the new sample set is closer to the SRB and covers different security modes with a small calculation time cost.

关键词： Clustering analysis principal component analysis(PCA) sample generation security region boundary(SRB)

Trend of Storm Surge Induced by Typical Landfall Super Typhoons During 1975–2021 in the Eastern China Sea

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Journal of Ocean university of China 2024年第2期23卷 277-286页

作者： LUO Feng WANG Yi TAO Aifeng SHI Jian WANG Yongzhi ZHANG Chi College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210098China Nantong Ocean and Coastal Engineering research institute Hohai UniversityNantong 226000China Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai UniversityNanjing 210098China College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China The First institute of Oceanography MNRQingdao 266061China

Climate change affects the activity of global and regional tropical cyclones(TCs).Among all TCs,typical super typhoons(STYs)are particularly devastating because they maintain their intensity when landing on the coast and thus cause casualties,economic losses,and environmental *** a 3D tidal model,we reconstructed the typhoon(TY)wind field to simulate the storm surge induced by typical *** TY activity was then analyzed using historical *** showed a downtrend of varying degrees in the annual frequency of STYs and TCs in the Western North Pacific(WNP)Basin,with a significant trend change observed for TCs from 1949 to 2021.A large difference in the interannual change in frequency was found between STYs and TCs in the WNP and Eastern China Sea(ECS).Along the coast of EC,the frequency of landfall TCs showed a weak downtrend,and the typical STYs showed reverse micro growth with peak activity in ***,Fujian,and Taiwan were highly vulnerable to the frontal hits of typical *** by climate change,the average lifetime maximum intensity(LMI)locations and landfall locations of typical STYs in the ECS basin showed a significant poleward migration *** addition,the annual average LMI and accumulated cyclone energy showed an uptrend,indicating the increasing severity of the disaster *** by the typical STY activity in the ECS,the maximum storm surge area also showed poleward migration,and the coast of North China faced potential growth in high storm surge risks.

关键词： storm surge super typhoons tropical cyclones eastern China Sea poleward migration

RB-DEM Modeling and Simulation of Non-Persisting Rough Open Joints Based on the IFS-Enhanced Method

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 337-359页

作者： Hangtian Song Xudong Chen Chun Zhu Qian Yin Wei Wang Qingxiang Meng Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China research institute of Geotechnical Engineering Hohai UniversityNanjing210098China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China

When the geological environment of rock masses is disturbed,numerous non-persisting open joints can appear within *** is crucial to investigate the effect of open joints on the mechanical properties of rock ***,it has been challenging to generate realistic open joints in traditional experimental tests and numerical *** paper presents a novel solution to solve the *** utilizing the stochastic distribution of joints and an enhanced-fractal interpolation system(IFS)method,rough curves with any orientation can be *** Douglas-Peucker algorithm is then applied to simplify these curves by removing unnecessary points while preserving their fundamental ***,open joints are created by connecting points that move to both sides of rough curves based on the aperture *** modeling is performed to construct the final mesh ***,the RB-DEM method is applied to transform the mesh model into a discrete element model containing geometric information about these open ***,this study explores the impacts of rough open joint orientation,aperture,and number on rock fracture *** method provides a realistic and effective approach for modeling and simulating these non-persisting open joints.

关键词： Non-persisting rough open joints stochastic distribution of joints enhanced-IFS method RB-DEM

Stability of the Stratification of Water Bodies in the North Passage of the Yangtze River Estuary Based on the EFDC Model

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Journal of Ocean university of China 2024年第1期23卷 23-32页

作者： WU De’an LI Xin WANG Yigang College of Harbor Coastal and Offshore EngineeringHohai UniversityNanjing 210098China Tianjin research institute For Water Transport Engineering Tianjin 300456China

To study the stratified stability of a water column in the North Passage of the Yangtze River Estuary,a numerical model of the hydrodynamics of this estuary is established using the EFDC *** the basis of EFDC results,this paper derives and pro-vides the discriminative index of water body stability caused by salinity and analyzes the along-range variation in water body strati-fication stability in the North Passage of the Yangtze River Estuary and the periodic variation at a key location(bend area)based on the simulation results of the numerical *** work shows that the water body in the bend area varies between mixed and strati-fied types,and the vertical average flow velocity has a good negative correlation with the differential velocity between the surface and bottom layers of the water *** model simulation results validate the formulae for the stratified stability discriminant during spring tides.

关键词： Yangtze Estuary North Passage EFDC model stratification stability salinity distribution

Sources, enrichment mechanisms, and resource effects of rare metal elements-enriched geothermal springs in Xizang, China

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Science China Earth Sciences 2024年第11期67卷 3476-3499页

作者： Fei XUE Hongbing TAN Xiying ZHANG Jinbao SU School of Earth Sciences and Engineering Hohai University Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes Qinghai Institute of Salt Lakes Chinese Academy of Sciences School of Oceanology Hohai University

Rare metals such as lithium(Li), rubidium(Rb), and cesium(Cs) are strategically crucial mineral resources for the development of emerging industries in China. Ensuring a stable long-term supply of these resources is essential. The geothermal systems in Xizang, China are well-developed, with a wide distribution of various types. Most high-temperature geothermal systems in Xizang are exceptionally enriched in rare metal elements(RMEs) and have the potential to become a new source of rare metals to secure China's strategic mineral resource supply in the future. A close relationship also exists between the geothermal system and the special salt lake resources on the Tibetan Plateau. Geothermal springs thus play a key role in the migration and enrichment of RMEs from deep to shallow parts of the crust, in the transition between endogenous and exogenous mineralization, and source-to-sink processes. However, the mechanisms of element enrichment and evolution in these springs have not been systematically discussed, and many theoretical issues remain to be investigated. Based on summarizing and analyzing previous research, this study employs hydrochemical and isotopic geochemistry methods to investigate typical geothermal springs across Xizang and explore the anomalous enrichment mechanism of RMEs, and the resource effects of geothermal springs. Comprehensive analysis shows that the total dissolved solids(TDS) and hydrochemical types of geothermal springs are similar to those of major geothermal fields worldwide, but the Tibetan springs are abnormally rich in Li(averaging5.48 mg/L), Rb(averaging 0.75 mg/L), and Cs(averaging 3.58 mg/L), which are hundreds to thousands of times more concentrated than natural waters. The distribution of these enriched geothermal springs is controlled by the Yarlung Zangbo suture zone and the extended N-S trending rifts, especially in the intersection zone of the two, where the geothermal springs are the most enriched. Based on the spatial distr

关键词： Geothermal springs Rare metal elements Enrichment mechanisms Salt lakes Tibetan Plateau

Nitrogen isotope stratigraphy of the Early Cambrian successions in the Tarim Basin:Spatial variability of nitrogen cycling and its implication for paleo-oceanic redox conditions

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Acta Geochimica 2024年第4期43卷 785-801页

作者： Bi Zhu Xuefeng Li Lu Ge Yongquan Chen institute of Earth’s Critical Zone School of Earth Sciences and EngineeringHohai UniversityNanjing 210098China research institute of Exploration and Development Tarim Oil Field CompanyPetroChinaKorlaChina

The Early Cambrian represents a critical time period characterized by extraordinary biological innovations and dynamic redox conditions in *** isotopic signatures of ancient sediments have the potential to elucidate the evolutionary path of marine redox states and the biogeochemical nitrogen cycle within the water column of the Early Cambrian *** existing research on this topic has predominantly focused on South China,the exploration of other continental margins has been limited,leaving contradictory hypotheses *** this study,pairedδ^(15)N andδ^(13)C org analyses were performed on the Lower Cambrian successions from the Shiairike section(inner ramp)and Well Tadong 2(deep shelf/basin)in the northwestern and eastern Tarim Basin,*** data from the Shiairike section reveal a discernible shift in the operation of different nitrogen cycles for the black chert-shale unit,also referred to as the black rock series in Chinese literature,of the Yurtus Formation(Fortunian stage to lower Stage 3).Oscillatingδ^(15)N values for its lower part are suggestive of alternating anaerobic assimilation of NH 4+and denitrification/*** is likely attributed to a shallow,unstable chemocline consistent with the upwelling and incursion of deep,anoxic waters during a major *** contrast,aerobic nitrogen cycling,indicated by positiveδ^(15)N values of>2‰,dominated the upper part alongside a reduction in upwelling *** the other hand,theδ^(15)N signatures of Xishanbulake and Xidashan Formations of Well Tadong 2,which encompass a time interval from the Cambrian Fortunian Age to Age 4,are indicative of N_(2)fixation by diazotrophs as the major nitrogen *** two studied intervals,although not time-equivalent,exhibit separated states of nitrogen cycling at least during the deposition of the Yurtus black rock *** spatially different nitrogen cycling of the studied sections is compatible with a redox-stratified ocean dur

关键词： Nitrogen isotopes Early Cambrian Tarim Black rock series

Floating plants reduced methane fluxes from wetlands by creating a habitat conducive to methane oxidation

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Journal of Environmental Sciences 2024年第1期135卷 149-160页

作者： Fuwei Wang Songhe Zhang Xiuren Hu Xin Lv Min Liu Yu Ma Benjamin Manirakiza Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Ministry of EducationHohai UniversityNanjing 210098China College of Environment Hohai UniversityNanjing 210098China China Machinery International Engineering Desigh and research institute co. Ltd.East China Regional CenterNanjing 210008China

Wetlands are one of the important natural sources of atmospheric methane (CH_4),as an important part of wetlands,floating plants can be expected to affect methane ***,the effects of floating plants on methane release are *** this study,methane fluxes,physiochemical properties of the overlying water,methane oxidation potential and rhizospheric bacterial community were investigated in simulated wetlands with floating plants Eichhornia crassipes,Hydrocharis dubia,and Trapa *** found that ***,***,and *** plants could inhibit 84.31%-97.31%,4.98%-88.91%and 43.62%-92.51%of methane fluxes at interface of water-atmosphere compared to Control,*** fluxes were negatively related to nutrients concentration in water column but positively related to the aerenchyma proportions of roots,stems,and *** the same biomass,root of *** (36.44%) had the highest methane oxidation potential,followed by *** (12.99%) and *** (11.23%).Forty-five bacterial phyla in total were identified on roots of three plants and 7 bacterial genera (2.10%-3.33%) were known *** I methanotrophs accounted for 95.07%of total *** pmoA gene abundances ranged from 1.90×10^(16)to 2.30×10^(18)copies/g fresh weight of root *** of pmoA gene was significantly positively correlated with environmental *** (5.40%) and methanotrophy (3.75%) function were closely related to methane *** study highlights that floating plant restoration can purify water and promote carbon neutrality partially by reducing methane fluxes through methane oxidation in wetlands.

关键词： Floating plants Methane fluxes Aerenchyma Methanotrophs

Assessment of runoff changes in the sub-basin of the upper reaches of the Yangtze River basin, China based on multiple methods

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Journal of Arid Land 2024年第4期16卷 461-482页

作者： WANG Xingbo ZHANG Shuanghu TIAN Yiman Department of Water Resources China Institute of Water Resources and Hydropower ResearchBeijing 100038China College of Hydrology and Water Resources Hohai UniversityNanjing 210098China

Quantitative assessment of the impact of climate variability and human activities on runoff plays a pivotal role in water resource management and maintaining ecosystem *** study considered six sub-basins in the upper reaches of the Yangtze River basin,China,to reveal the trend of the runoff evolution and clarify the driving factors of the changes during 1956–*** regression,Mann-Kendall test,and sliding t-test were used to study the trend of the hydrometeorological elements,while cumulative distance level and ordered clustering methods were applied to identify mutation *** contributions of climate change and human disturbance to runoff changes were quantitatively assessed using three methods,i.e.,the rainfall-runoff relationship method,slope variation method,and variable infiltration capacity(Budyko)hypothesis ***,the availability and stability of the three methods were *** results showed that the runoff in the upper reaches of the Yangtze River basin exhibited a decreasing trend from 1956 to 2020,with an abrupt change in *** attribution analysis,the runoff series could be divided into two phases,i.e.,1961–1985(baseline period)and 1986–2020(changing period);and it was found that the rainfall-runoff relationship method with precipitation as the representative of climate factors had limited usability compared with the other two methods,while the slope variation and Budyko hypothesis methods had highly consistent *** factors showed different effects in the sub-basins of the upper reaches of the Yangtze River ***,human disturbance was the main factor that contributed to the runoff changes,accounting for 53.0%–82.0%;and the contribution of climate factors to the runoff change was 17.0%–47.0%,making it the secondary factor,in which precipitation was the most representative climate *** results provide insights into how climate and anthropogenic changes synergistically influence the runoff of t

关键词： economic belt runoff change influencing assessment climate human activities

The Short-Term Prediction ofWind Power Based on the Convolutional Graph Attention Deep Neural Network

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Energy Engineering 2024年第2期121卷 359-376页

作者： Fan Xiao Xiong Ping Yeyang Li Yusen Xu Yiqun Kang Dan Liu Nianming Zhang State Grid Hubei Electric Power research institute Wuhan430077China College of Energy and Electrical Engineering Hohai UniversityNanjing210098China

The fluctuation of wind power affects the operating safety and power consumption of the electric power grid and restricts the grid connection of wind power on a large ***,wind power forecasting plays a key role in improving the safety and economic benefits of the power *** paper proposes a wind power predicting method based on a convolutional graph attention deep neural network with multi-wind farm *** on the graph attention network and attention mechanism,the method extracts spatial-temporal characteristics from the data of multiple wind ***,combined with a deep neural network,a convolutional graph attention deep neural network model is ***,the model is trained with the quantile regression loss function to achieve the wind power deterministic and probabilistic prediction based on multi-wind farm spatial-temporal data.A wind power dataset in the *** taken as an example to demonstrate the efficacy of the proposed *** with the selected baseline methods,the proposed model achieves the best prediction *** point prediction errors(i.e.,root mean square error(RMSE)and normalized mean absolute percentage error(NMAPE))are 0.304 MW and 1.177%,*** the comprehensive performance of probabilistic prediction(i.e.,con-tinuously ranked probability score(CRPS))is ***,the significance of multi-wind farm data and spatial-temporal feature extraction module is self-evident.

关键词： Format wind power prediction deep neural network graph attention network attention mechanism quantile regression