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Probing dark matter particles from evaporating primordial black holes via electron scattering in the CDEX-10 experiment

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Science China(Physics,Mechanics & Astronomy) 2024年第10期Mechanics & Astronomy) .卷 87-95页

作者： Zhenhua Zhang Litao Yang Qian Yue Kejun Kang Yuanjing Li Haipeng An Greeshma C. Jianping Chang Yunhua Chen Jianping Cheng Wenhan Dai Zhi Deng Changhao Fang Xinping Geng Hui Gong Qiuju Guo Tao Guo Xuyuan Guo Li He Shengming He Jinwei Hu Hanxiong Huang Tuchen Huang Lin Jiang S.Karmakar Haubin Li Hanyu Li Jianmin Li Jin Li Qianyun Li Renmingjie Li Xueqian Li Yulan Li Yifan Liang Bin Liao FongKay Lin ShinTed Lin Jiaxuan Liu Shukui Liu Yandong Liu Yu Liu Yuanyuan Liu Hao Ma Yucai Mao Qiyuan Nie Jinhua Ning Hui Pan Ningchun Qi Jie Ren Xichao Ruan Monoj Kumar Singh Tianxi Sun Changjian Tang Yang Tian Guangfu Wang Junzheng Wang Li Wang Qing Wang Yufeng Wang Yunxiang Wang Henry Tsz-King Wong Shiyong Wu Yucheng Wu Haoyang Xing Rui Xu Yin Xu Tao Xue Yulu Yan Nan Yi Chunxu Yu Haijun Yu Jianfeng Yue Ming Zeng Zhi Zeng Bingtao Zhang Fengshou Zhang Lei Zhang Zhenyu Zhang Jizhong Zhao Kangkang Zhao Minggang Zhao Jifang Zhou Zuying Zhou Jingjun Zhu CDEX Collaboration Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of engineering Physics Tsinghua University Department of Physics Tsinghua University Institute of Physics Academia Sinica NUCTECH Company YaLong River hydropower Development Company College of Nuclear Science and Technology Beijing Normal University College of Physics Sichuan University school of Physics Peking University Department of Nuclear Physics China Institute of Atomic Energy Sino-French Institute of Nuclear and Technology Sun Yet-sen University school of Physics Nankai University Department of Physics Banaras Hindu University Department of Physics Beijing Normal University

Dark matter（DM） is a major constituent of the ***,no definite evidence of DM particles（denoted as “χ”） has been found in DM direct detection（DD） experiments to *** is a novel concept of detectingχfrom evaporating primordial black holes（PBHs）.We search forχemitted from PBHs by investigating their interaction with target *** examined PBH masses range from 1×1015to 7×1016g under the current limits of PBH abundance *** 205.4 kg·day data obtained from the CDEX-10 experiment conducted in the China Jinping Underground Laboratory,we exclude the χ-electron（χ-e） elastic-scattering cross section σχe～5×10-29cm2for χ with a mass ■ keV from our *** the higher radiation background but lower energy threshold（160 eV）,CDEX-10 fills a part of the gap in the previous *** (mχ,σχe) can be determined in the future,DD experiments are expected to impose strong constraints on fPBHfor large MPBHs.

关键词： CDEX primordial black hole light dark matter particle dark matter-electron scattering high purity germanium detector

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THEORETICAL RELATIONS OF BOUNDARY DISPLACEMENT DERIVATIVES AND TRACTIONS AT SINGULAR BOUNDARY POINT FOR 2D ISOTROPIC ELASTIC PROBLEMS

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Acta Mechanica Solida Sinica 2008年第5期21卷 389-402页

作者： Zailiang Li Cheng Wang Digital engineering and Simulation Research Center School of Hydropower and Digitalization Engineering Huazhong University of Science ＆ Technology Wuhan 430074 China

Although boundary displacement and traction are independent field variables in boundary conditions of an elasticity problem at a non-singular boundary point, there exist definite relations of singularity intensities between boundary displacement derivatives and tractions at a singular boundary point. The analytical forms of the relations at a singular smooth point for 2D isotropic elastic problems have been established in this work. By using the relations, positions of the singular boundary points and the corresponding singularity intensities of the unknown boundary field variables can be determined a priori. Therefore, more appropriate shape functions of the unknown boundary field variables in singular elements can be constructed. A numerical example shows that the accuracy of the BEM analysis using the developed theory is greatly increased.

关键词： boundary displacement and traction discontinuity of the first kind weak singularity boundary element method

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Advancing flood susceptibility modeling using stacking ensemble machine learning: A multi-model approach

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Journal of Geographical Sciences 2024年第8期34卷 1513-1536页

作者： YANG Huilin YAO Rui DONG Linyao SUN Peng ZHANG Qiang WEI Yongqiang SUN Shao AGHAKOUCHAK Amir school of Geography and Tourism Anhui Normal UniversityWuhu 241002AnhuiChina Changjiang River Scientific Research Institute Wuhan 430015China Advanced Interdisciplinary Institute of Environment and Ecology Beijing Normal UniversityZhuhai 519087GuangdongChina Hunan Institute of Water Resources and hydropower Research Changsha 410007China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Department of Civil and Environmental engineering University of California IrvineIrvineCA 92697USA

Flood susceptibility modeling is crucial for rapid flood forecasting, disaster reduction strategies, evacuation planning, and decision-making. Machine learning(ML) models have proven to be effective tools for assessing flood susceptibility. However, most previous studies have focused on individual models or comparative performance, underscoring the unique strengths and weaknesses of each model. In this study, we propose a stacking ensemble learning algorithm that harnesses the strengths of a diverse range of machine learning models. The findings reveal the following:(1) The stacking ensemble learning, using RF-XGBCB-LR model, significantly enhances flood susceptibility simulation.(2) In addition to rainfall,key flood drivers in the study area include NDVI, and impervious surfaces. Over 40% of the study area, primarily in the northeast and southeast, exhibits high flood susceptibility, with higher risks for populations compared to cropland.(3) In the northeast of the study area,heavy precipitation, low terrain, and NDVI values are key indicators contributing to high flood susceptibility, while long-duration precipitation, mountainous topography, and upper reach vegetation are the main drivers in the southeast. This study underscores the effectiveness of ML, particularly ensemble learning, in flood modeling. It identifies vulnerable areas and contributes to improved flood risk management.

关键词： flood susceptibility assessment machine learning stacking ensemble learning flood drivers XiangjiangRiverBasin

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Rockburst criterion and evaluation method for potential rockburst pit depth considering excavation damage effect

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Journal of Rock Mechanics and Geotechnical engineering 2024年第5期16卷 1649-1666页

作者： Jinhao Dai Fengqiang Gong Lei Xu engineering Research Center of Safety and Protection of Explosion & Impact of Ministry of Education (ERCSPEIME) Southeast UniversityNanjing211189China school of Civil engineering Southeast UniversityNanjing211189China

Excavation-induced disturbances in deep tunnels will lead to deterioration of rock properties and formation of excavation damaged zone(EDZ).This excavation damage effect may affect the potential rockburst pit *** two diversion tunnels of Jinping II hydropower station for example,the relationship between rockburst pit depth and excavation damage effect is first *** results indicate that the rockburst pit depth in tunnels with severe damage to rock masses is relatively ***,the excavation-induced damage effect is characterized by disturbance factor D based on the Hoek-Brown criterion and wave velocity *** is found that the EDZ could be further divided into a high-damage zone(HDZ)with D=1 and weak-damage zone(WDZ),and D decays from one to zero *** this,a quantitative evaluation method for potential rockburst pit depth is established by presenting a three-element rockburst criterion considering rock strength,geostress and disturbance *** evaluation results obtained by this method match well with actual *** addition,the weakening of rock mass strength promotes the formation and expansion of potential rockburst *** potential rockburst pit depth is positively correlated with HDZ and WDZ depths,and the HDZ depth has a significant contribution to the potential rockburst pit depth.

关键词： Deep tunnel Rockburst Rockburst pit Excavation damage effect Hoek-Brown criterion

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A combined computational/experimental study of anode-concerned voltage drop in aqueous primary Mg-air batteries

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Journal of Magnesium and Alloys 2024年第5期12卷 1854-1866页

作者： Wen Xu Min Deng Darya Snihirova Linqian Wang Yulong Wu Sviatlana V.Lamaka Mikhail L.Zheludkevich Daniel Hoche Institute of Surface Science Helmholtz-Zentrum Hereon21502 GeesthachtGermany school of Materials Science and engineering Hebei University of Technology300000TianjinChina Institute for Materials Science Faculty of EngineeringKiel University24143 KielGermany

The voltage drop appearing at Mg anode-electrolyte interface is a critical issue for the battery power and energy density of aqueous primary Mg-air *** respective voltage loss is typically assigned to the deposits layer forming on the anode surface during *** this work,we experimentally and computationally investigate the critical factors affecting the voltage drop at Mg anode towards a deeper understanding of the contribution of deposit and its growth.A two-dimensional(2D)mathematical model is proposed to compute the voltage drop of Mg-0.15Ca wt.%alloy(Mg-0.15Ca)by means of a semi-empirical formulas and experiments-based modification model,considering the effect of discharge current density,the negative difference effect(NDE)and surface deposits layer *** model is utilized to simulate the discharge potential of the anode at predefined experimental current *** computed voltage drop(half-cell voltage)is in good agreement with the experimental *** applicability of the mathematical model is successfully validated on the second material(namely high-purity Mg).

关键词： Aqueous Mg-air battery Voltage drop NDE Charge transfer Deposits-related resistances

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Identification of the non-stationarity of extreme temperature events and teleconnections with solar activity and large-scale atmospheric circulation: A case study in the Yangtze River Economic Belt

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Journal of Earth Science 2024年

作者： Lin Zhang Jingyun Ling Shengzhi Huang Hongbin Zhan Yi Wu Menggui Jin Qiang Huang State Key Laboratory of Eco-hydraulics in Northwest Arid Region， Xi'an University of Technology College of Design and engineering， National University of Singapore Yinshanbeilu Grassland Eco-Hydrology National Observation and Research Station， China Institute of Water Resources and hydropower Research Department of Geology and Geophysics， Texas A&M University， College Station school of Earth System Science， Tianjin University school of Environmental Studies， China University of Geosciences

In recent decades， extreme climate events have become a major problem worldwide. To understand the uncertainty in the response of extreme events to global warming， regional assessments are required for various climatic and geographic regions. The spatiotemporal distribution of extreme temperature events in the Yangtze River Economic Belt (YREB) from 1960 to 2019， including interannual changes and their teleconnections with solar activity and large-scale atmospheric circulation， were analyzed using eight indices of extreme temperature events. Over the past six decades， the climate in the YREB region has seen a warming trend， characterized by an increase in extreme warm events and a decrease in extreme cold events. The extreme temperature indices exhibit strong spatial variability. The warm extremes display a significant upward trend across the YREB， while cold extremes are primarily concentrated in the western part of the region. In recent decades， both warm and cold extremes have significant interannual variations， and these events predominantly oscillate over periods of less than four years. After 1985， the relationship between El Ni?o-Southern Oscillation (ENSO)， Arctic Oscillation (AO)， Pacific Decadal Oscillation (PDO) and extreme temperature events has changed significantly compared with pre-1985， and the direction of the phase angle can determine the positive and negative effects of the two time-series. ENSO， AO and PDO mainly have positive impacts on extreme temperature events， with ENSO and AO exerting greater impacts than PDO. In contrast， solar activity mainly has a negative impact on these events. Furthermore， the notable interdecadal changes in extreme temperature events， especially warm extremes， may be caused by the shift in the PDO phase. Therefore， the results of the study are important for the YREB region to take effective measures to mitigate the potential impacts of human activities on regional warming.

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Effects of the Rainfall-Triggered Lisse Effect on the Stability of Loess Slopes

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Journal of Earth Science 2024年第4期35卷 1254-1262页

作者： Zhizhou Yang Donghui Cheng Jun Xia school of Water and Environment Chang’an UniversityXi’an710054China Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education Chang’an UniversityXi’an710054China Key Laboratory of Eco-Hydrology and Water Security in Arid and Semi-Arid Regions of the Ministry of Water Resources Chang’an UniversityXi’an710054China Key Laboratory of Water Cycle&Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China State Key Laboratory of Water Resources&hydropower engineering Sciences Wuhan UniversityWuhan430000China

This paper coupled a water-air two-phase hydrodynamic(WATPH)model with the Iverson’s method to analyze the influence of the Lisse effect on the fast groundwater pressure(P_(w))response and the slope ***,the sensitivities of the driving force and loess soil parameters were *** showed that the WATPH model simulated the height and rise of the depth to the water table reasonably *** depth to water table before rainfall(H0)had a significant impact on the Lisse effect and the slope *** the H_(0) was less than approximately 1 m,the rainfall triggered a significant Lisse effect and decreased the slope factor of safety(F_(s)).When the rainfall intensity(R_(i))was higher than the saturated hydraulic conductivity(K_(s)),the Lisse effect and the F_(s) slightly changed with the increase of the R_(i),and the slope tended to be unstable with continuous *** increasing K_(s),the Lisse effect noticeably increased,and the minimum F_(s) quickly *** analysis of the normalized sensitivity coefficient revealed that H_(0) had a dramatic impact on the Lisse effect and loess slope *** different R_(i) and K_(s) values had prominent influences on the Lisse effect and slight impacts on F_(s).

关键词： Lisse effect landslides safety factor rainfall

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2000-2021年降水对黄河流域植被和地表水的影响

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Journal of Geographical Sciences 2024年第4期34卷 633-653页

作者：时晓蕊杨鹏夏军张永勇黄河清朱艳超 Hubei Key Laboratory of Regional Ecology and Environmental Change School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China National engineering Research Center for Geographic Information System China University of GeosciencesWuhan 430074China State Key Laboratory of Water Resources and hydropower engineering Science Wuhan UniversityWuhan 430072China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China

The Yellow River Basin (YRB) is a vital ecological zone in China owing to its sensitive and fragile *** the long-term influence of climate changes and artificial factors,the relationship between precipitation,vegetation,and surface water in the YRB has changed drastically,ultimately affecting the water resources and environmental ***,we applied multivariate statistical analysis to investigate the precipitation,normalized difference vegetation index (NDVI),and surface water changes in the YRB from 2000to ***,we attempted to clarify the ecological effects of precipitation by explaining the relationship between precipitation and vegetation in terms of the time-lag relationship using the Integrated Multi-satellite Retrievals for Global Precipitation Measurement algorithm,Moderate Resolution Imaging Spectroradiometer,and hydrological ***,vegetation,and area of surface water in the YRB showed increasing trends from 2000–2021 (e.g.,7.215 mm/yr,0.004 NDVI/yr,and 0.932 km^(2)/yr,respectively).The water level in the upper reaches of the YRB showed a downward trend,whereas that in the middle and lower reaches exhibited an upward *** in precipitation had a positive effect on vegetation and surface water in the YRB,with correlation coefficients of 0.63 and0.51,*** responses of NDVI and surface water elevation to precipitation were heterogeneous and delayed,with the majority showing a lag time of approximately≤16 ***,the lag times of Longyangxia Lake and Ngoring-Co Lake were 0 and 8 days,*** showed that precipitation variability can effectively explain vegetation improvement and increases in surface water elevation,while providing a proven scenario for predicting the surface water and vegetation productivity under the influence of climate change.

关键词： precipitation vegetation cover surface water spatial and temporal variation Yellow River Basin

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Theoretical analysis and numerical simulation of mechanical energy loss and wall resistance of steady open channel flow

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Journal of Hydrodynamics 2016年第3期28卷 489-496页

作者：刘士和薛娇 school of Water Resources and hydropower engineering Wuhan University

The mechanical energy loss and the wall resistance are very important in practical engineering. These problems are investigated through theoretical analysis and numerical simulation in this paper, The results are as follows. （1） A new mechanical energy equation for the total flow is obtained, and a general formula for the calculation of the mechanical energy loss is proposed. （2） The general relationship between the wall resistance and the mechanical energy loss for the steady channel flow is obtained, the simplified form of which for the steady uniform channel flow is in consistent with the formula used in Hydraulics deduced by 7r theorem and dimensional analysis. （3） The steady channel flow over a backward facing step with a small expansion ratio is numerica- lly simulated, and the mechanical energy loss, the wall resistance as well as the relationship between the wall resistance and the mechanical energy loss are calculated and analyzed.

关键词： channel flow energy equation mechanical energy loss resistance

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Improving Network Availability through Optimized Multipath Routing and Incremental Deployment Strategies

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Computers, Materials & Continua 2024年第7期80卷 427-448页

作者： Wei Zhang Haijun Geng Computer Application Teaching and Research Section China University of Labor RelationsBeijing100048China school of Automation and Software engineering Shanxi UniversityTaiyuan030006China

Currently,distributed routing protocols are constrained by offering a single path between any pair of nodes,thereby limiting the potential throughput and overall network *** approach not only restricts the flow of data but also makes the network susceptible to failures in case the primary path is *** contrast,routing protocols that leverage multiple paths within the network offer a more resilient and efficient *** routing,as a fundamental concept,surpasses the limitations of traditional shortest path first *** not only redirects traffic to unused resources,effectively mitigating network congestion,but also ensures load balancing across the *** optimization significantly improves network utilization and boosts the overall performance,making it a widely recognized efficient method for enhancing network *** further strengthen network resilience against failures,we introduce a routing scheme known as Multiple Nodes with at least Two Choices(MNTC).This innovative approach aims to significantly enhance network availability by providing each node with at least two routing *** doing so,it not only reduces the dependency on a single path but also creates redundant paths that can be utilized in case of failures,thereby enhancing the overall resilience of the *** ensure the optimal placement of nodes,we propose three incremental deployment *** algorithms carefully select the most suitable set of nodes for deployment,taking into account various factors such as node connectivity,traffic patterns,and network *** deployingMNTCon a carefully chosen set of nodes,we can significantly enhance network reliability without the need for a complete overhaul of the existing *** have conducted extensive evaluations of MNTC in diverse topological spaces,demonstrating its effectiveness in maintaining high network availability with minimal path *** results are impressive,sh

关键词： Multipath routing network availability incremental deployment schemes genetic algorithm

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