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Comparative study of different machine learning models in landslide susceptibility assessment: A case study of Conghua District, Guangzhou, China

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China Geology 2024年第1期7卷 104-115页

作者： Ao Zhang Xin-wen Zhao Xing-yuezi Zhao Xiao-zhan Zheng Min Zeng Xuan Huang Pan Wu Tuo Jiang Shi-chang Wang Jun He Yi-yong Li Wuhan center China Geological SurveyMinistry of Natural Resources(Geosciences Innovation Center of Central South China)Wuhan 430205China Guangzhou Institute of Geological Survey Guangzhou 510080China Hubei Transportation Planning Design Institute Co. LtdWuhan 430050China

Machine learning is currently one of the research hotspots in the field of landslide *** clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,Conghua District,which is the most prone to landslide disasters in Guangzhou,was selected for landslide susceptibility *** evaluation factors were selected by using correlation analysis and variance expansion factor *** four machine learning methods namely Logistic Regression(LR),Random Forest(RF),Support Vector Machines(SVM),and Extreme Gradient Boosting(XGB),landslide models were *** analysis and evaluation of the model were conducted through statistical indices and receiver operating characteristic(ROC)*** results showed that LR,RF,SVM,and XGB models have good predictive performance for landslide susceptibility,with the area under curve(AUC)values of 0.752,0.965,0.996,and 0.998,*** model had the highest predictive ability,followed by RF model,SVM model,and LR *** frequency ratio(FR)accuracy of LR,RF,SVM,and XGB models was 0.775,0.842,0.759,and 0.822,*** and XGB models were superior to LR and SVM models,indicating that the integrated algorithm has better predictive ability than a single classification algorithm in regional landslide classification problems.

关键词： Landslides susceptibility assessment Machine learning Logistic Regression Random Forest Support Vector Machines XGBoost Assessment model Geological disaster investigation and prevention engineering

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Provenance of the Southeastern South China Block in the Late Triassic and Initiation of Paleo-Pacific Subduction:Evidence from Detrital Zircon U-Pb Geochronology

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Journal of Earth Science 2024年第5期35卷 1426-1446页

作者： Jintao Kong Zhongjie Xu Rihui Cheng Duo Wan College of Earth Sciences Jilin UniversityChangchun 130061China Key Laboratory of Mineral resources Evaluation in Northeast Asia Ministry of Natural and ResourcesChangchun 130061China

During the Late Paleozoic-Early Mesozoic Era,the sediment transport system and tectonic regime in the southeastern margin of the South China Block(SESCB)all changed,significantly affected by the Paleo-Pacific ***,controversy exists about the Paleo-Pacific subduction's initiation *** study uses detrital zircon U-Pb ages to discuss the Late Triassic source-tosink system in the *** provides some references for the Paleo-Pacific subduction process based on crucial age information and zircons'trace *** paleogeography and similarity of detrital zircon age distribution indicate that three sinks were found in the SESCB during the Late Triassic:*** Yangchun-Kaiping-Gaoming area,comprising major age ranges of 260-220,460-400,and 1200-800 Ma,which might be sourced from the Yunkai terrane;*** Jiexi-Kanshi-Nanjing area,characterized by the significant age component of 2000-1800 Ma,which corresponded to the Wuyi terrane;*** Xinan area,consisting of significant age groups of 290-250 and 380-320 Ma,which might be sourced from the magmatic rocks formed by the Huinan Movement and Paleo-Pacific *** that 290-250 Ma zircons were widely distributed in the Upper Triassic strata,and their trace elements suggested the existence of a magmatic arc near the SESCB during the 290-250 ***,we propose that the Paleo-Pacific subduction might have begun in the Early Permian.

关键词： detrital zircon geochronology South China Block Paleo-Pacific Block provenance analysis geochronology geochemistry

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Stress tensor determination by modified hydraulic tests on pre-existing fractures:Method and stress constraints

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1637-1648页

作者： Guiyun Gao Chenghu Wang Ke Gao National Institute of natural Hazards Ministry of Emergency Management of ChinaBeijing100085China Beijing Engineering Research center of Earthquake Observation Beijing100085China Key Laboratory of Compound and Chained natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing100085China Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen518055China

The hydraulic testing of pre-existing fractures(HTPF)is one of the most promising in situ stress measurement methods,particularly for three-dimensional stress tensor ***,the stress tensor determination based on the HTPF method requires at least six tests or a minimum of 14-15 tests(under different conditions)for reliable *** this study,we modified the HTPF method by considering the shear stress on each pre-existing fracture,which increased the number of equations for the stress tensor determination and decreased the number of tests *** shear stresses were attributed to different fractures by random sampling;therefore,the stress tensors were obtained by searching for the optimal solution using the least squares criterion based on the Monte Carlo ***,we constrained the stress tensor based on the tensile strength criterion,compressive strength criterion,and vertical stress *** inverted stress tensors were presented and analyzed based on the tensorial nature of the stress using the Euclidean mean stress *** stress-measurement campaigns in Weifang(Shandong Province,China)and Mercantour road tunnel(France)were implemented to highlight the validity and efficiency of the modified HTPF(M-HTPF)*** results showed that the M-HTPF method can be applied for stress tensor inversion using only three to four tests on pre-existing fractures,neglecting the stress *** inversion results were confined to relatively small distribution dispersions and were significantly reliable and stable due to the shear stresses on the fractures and the stress constraints *** M-HTPF method is highly feasible and efficient for complete stress tensor determination in a single borehole.

关键词： Stress tensor Hydraulic tests on pre-existing fractures Mean stress Stress constraint Hydraulic fracturing

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Responding of zooplankton to environmental factor changes in the Changjiang River estuarine regions in spring-summer from 2016 to 2020

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Journal of Oceanology and Limnology 2024年第2期42卷 544-559页

作者： Jieqing YANG Dongrong ZHANG Yuange CHEN Longling OUYANG Yangyang YANG Jin ZHOU Yunrong SHI East China Sea Fisheries Research Institute Chinese Academy of Fishery SciencesKey Laboratory of East China Sea Fishery Resources ExploitationMinistry of Agriculture and Rural AffairsShanghai 200090China Key Laboratory of Engineering Oceanography Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China College of Marine Ecology and Environment Shanghai Ocean UniversityShanghai 201306China

The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in ***,understanding the relationships between zooplankton and environmental factors help us know the water *** achieve co-existence with species in similar ecological group or habit,they could inevitably alter themselves to fit the ecology and adjust the function according to the competitive exclusion in ecological ***,information of the co-existence of dominant species in the Changjiang(Yangtze)River estuary(CRE)and adjacent waters remains *** explored the relationships between dominant zooplankton and environmental factors in the study region in spring-summer from 2016 to 2020,involving particularly the composition of dominant species,ecological groups,their relationships with environmental factors,and co-existence of important species,using the non-multidimensional scale analysis(nMDS)method and redundancy *** show that Labidocera euchaeta and Tortanus vermiculus were dominant species in the study *** turnover rate of dominant zooplankton was greater(>50%)in spring while the species number was higher in *** dominant species were estuarine,offshore,and eurytopic based on the adaptation to *** spring,the ecological groups were dominated by estuarine species,while in summer by estuarine and offshore *** addition,the nMDS showed that the dominant species in the same ecological group were more dispersed and not prominently clustered;the dominant species were staggered among different ecological *** temperature,salinity,pH,dissolved oxygen,and chlorophyll a were the main environmental factors on the distribution of the dominant species in spring,while in summer were dissolved oxygen,temperature,salinity,and *** domination of medusae of Nemopsis bachei and Pleurobrachia globosa in zo

关键词： Changjiang River estuary(CRE) zooplankton dominant species ecological group environmental factor co-existence

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A demand forecasting model for urban air mobility in Chengdu,China

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Green Energy and Intelligent Transportation 2024年第3期3卷 11-23页

作者： Wenqiu Qu Jie Huang Chenglong Li Xiaohan Liao State Key Laboratory of resources and Environment information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of resources and Environment University of Chinese Academy of SciencesBeijing 100101China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Civil Aviation Flight University of China Guanghan618307China The Research center for UAV Applications and Regulation CASBeijing 100101China

The successful application of new technologies such as remotely piloted aircraft systems,distributed electric propulsion systems,and automatic control systems on electric vertical take-off and landing(eVTOL)aircraft has prompted Urban Air Mobility(UAM)to be mentioned *** is a newly raised transport mode of using eVTOL aircraft to transport people and cargo in urban areas,which is thought to share some of the traffic on the *** of the prerequisites for UAM to operate on a regular basis is that its demand can support the operating costs,so forecasting UAM demand is *** conduct UAM demand forecasting based on the four-step method,focusing on improving the third-step modal split,and propose a demand forecasting model based on the logit *** model combines a nested logit(NL)model with a multinomial logit(MNL)model to solve the problem of non-existent UAM sharing *** use Chengdu,China as an example,and focus on forecasting the UAM traffic demand in 2030 with the help of the four-step *** results show that UAM is suitable for shared operation during the early *** a fully shared operation,the UAM share rate increases by 0.73%for every kilometer increase in ***,UAM is more competitive than other modes for delivery distances exceeding 15 ***,using the distributions of the share rate and traffic flow pattern from the simulation,we propose the routes that can be prioritized for UAM operations in Chengdu.

关键词： Urban air mobility Four-step method Demand forecasting Logit model Share rate

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Characteristics and triggering mechanisms of early negative Indian Ocean Dipole

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Acta Oceanologica Sinica 2024年第3期43卷 59-65页

作者： Yue Fang Shuangwen Sun Yongcan Zu Jianhu Wang Lin Feng First Institute of Oceanography and Key Laboratory of Marine Science and Numerical ModelingMinistry of Natural ResourcesQingdao 266061China Laboratory for Regional Oceanography and Numerical Modeling Qingdao Marine Science and Technology CenterQingdao 266237China Shandong Key Laboratory of Marine Science and Numerical Modeling Qingdao 266061China

Negative Indian Ocean Dipole(nIOD)can exert great impacts on global climate and can also strongly influence the climate in *** nIOD is a major type of nIOD,which can induce more pronounced climate anomalies in summer than La Niña-related ***,the characteristics and triggering mechanisms of early nIOD are *** results based on reanalysis datasets indicate that the early nIOD and La Niña-related nIOD are the two major types of nIOD,and the former accounts for over one third of all the nIOD events in the past six *** two types of nIODs are similar in their intensities,but are different in their spatial patterns and seasonal *** early nIOD,which develops in spring and peaks in summer,is one season earlier than the La Niña-related *** spatial pattern of the wind anomaly associated with early nIOD exhibits a winter monsoon-like pattern,with strong westerly anomalies in the equatorial Indian Ocean and eastly anomalies in the northern Indian *** to the triggering mechanism of early positve IOD,the early nIOD is induced by delayed Indian summer monsoon *** results of this study are helpful for improving the prediction skill of IOD and its climate impacts.

关键词： Indian Ocean Dipole(IOD) triggering mechanism Indian summer monsoon seasonal cycle negative IOD

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Supplementation of alanine improves biomass accumulation and lipid production of Chlorella pyrenoidosa by increasing the respiratory and metabolic processes

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Journal of Oceanology and Limnology 2024年第2期42卷 570-579页

作者： Yongfu LI Tianze ZHAO Wei SUN Ruiwen GAO Guangyuan MA Jiangsu Province Engineering Research center for Marine Bioresources Sustainable Utilization Key Laboratory of Marine Hazards ForecastingMinistry of Natural ResourcesHohai UniversityNanjing 210098China College of Oceanography Hohai UniversityNanjing 210098China Jiangsu Innovation center of Marine Bioresources Jiangsu Coast Development Group Co.Ltd.Nanjing 210019China

The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was *** shows that the supplementation of Ala increased *** biomass and lipid production in an 8-d batch *** concentration of 10 mmol/L of Ala was optimum and increased the microalgal cell biomass and lipid content by 39.3%and 21.4%,respectively,compared with that in the control(0-mmol/L Ala).Ala supplementation reduced photosynthetic activity while boosting respiratory activity and pyruvate levels,indicating that *** used exogenous Ala for biomass accumulation through the respiratory metabolic *** accelerated respiratory metabolism due to Ala supplementation elevated the substrate pool and improved the lipogenic gene expression,promoting lipid production at *** study provided a novel method for increasing biomass accumulation and lipid production and elucidated the role of Ala in regulating lipid production.

关键词： alanine Chlorella pyrenoidosa lipid respiration lipogenic gene

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Global patterns of soil phosphatase responses to nitrogen and phosphorus fertilization

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Pedosphere 2024年第1期34卷 200-210页

作者： Xiaomei GOU Yongqing REN Xin QIN Xiaorong WEI Jingjing WANG State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau the Research Center of Soil and Water Conservation and Ecological EnvironmentChinese Academy of Sciences and Ministry of EducationYangling 712100China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China River and Lake Management Office Shaanxi Provincial Department of Water ResourcesXi'an 710004China College of natural resources and Environment Northwest A&F UniversityYangling 712100China University of Chinese Academy of Sciences Beijing 100049China CAS center for Excellence in Quaternary Science and Global Change Xi'an 710061China

Hydrolysis of organic phosphorus(P) by soil phosphatases is an important process of P cycling in terrestrial ecosystems, significantly affected by nitrogen(N) and/or P fertilization. However, how soil acid phosphatase(ACP) and alkaline phosphatase(ALP) activities respond to N and/or P fertilization and how these responses vary with climatic regions, ecosystem types, and fertilization management remain unclear. This knowledge gap hinders our ability to assess P cycling and availability from a global perspective. We performed a meta-analysis to evaluate the global patterns of soil ACP and ALP activities in response to N and/or P addition. We also examined how climatic regions(arctic to tropical), ecosystem types(cropland, grassland, and forest), and fertilization management(experiment duration and fertilizer type and application rate) affected changes in soil phosphatases after fertilization. It was shown that N fertilizer resulted in 10.1% ± 2.9% increase in soil ACP activity but a minimal effect on soil ALP activity. In contrast, P fertilizer resulted in 7.7% ± 2.6% decrease in soil ACP activity but a small increase in soil ALP activity. The responses of soil ACP and ALP activities to N and/or P fertilization were largely consistent across climatic regions but varied with ecosystem types and fertilization management, and the effects of ecosystem types and fertilization management were enzyme-dependent. Random forest analysis identified climate(mean annual precipitation and temperature) and change in soil pH as the key factors explaining variations in soil ACP and ALP activities. Therefore, N input and ecosystem types should be explicitly disentangled when assessing terrestrial P cycling.

关键词： acid phosphatase alkaline phosphatase ecosystem type fertilization management meta-analysis phosphorus cycling phosphorus limitation

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Improving landscape connectivity through habitat restoration:application for Asian elephant conservation in Xishuangbanna Prefecture,China

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Integrative Zoology 2024年第2期19卷 319-335页

作者： Bin WAN Wenwen LI Peng LIU Nian YANG Shang CHEN Xianming GUO Bin WANG Li ZHANG Key Laboratory for Biodiversity Science and Ecological Engineering Ministry of EducationCollege of Life SciencesBeijing Normal UniversityBeijingChina Research center for Coastal Zone Science and Marine Development Strategy First Institute of OceanographyMinistry of Natural ResourcesQingdaoChina School of Biological Sciences The University of Hong KongPokfulamHong KongChina Research Institute of Xishuangbanna National Nature Reserve JinghongChina Xishuangbanna Asian Elephant Conservation and Management center JinghongChina

Habitat restoration is an effective method for improving landscape connectivity,which can reduce habitat *** landscape connectivity could promote connections between habitat,which is extremely essential to preserve gene flow and population *** study proposes a methodological framework to analyze landscape connectivity for Asian elephant habitat conservation,aiming to provide practical options for reducing habitat fragmentation and improving habitat *** approach involved combining a species distribution model using MaxEnt and landscape functional connectivity models using graph theory to assess the impact on connectivity improvement via farmland/plantation restoration as *** results showed that:(1)there were 119 suitable habitat patches of Asian elephant covering a total area of 1952.41 km^(2).(2)The connectivity between habitats improved significantly after vegetation restoration and the gain first decreased and then increased with the increase of dispersal distance.(3)The first few new habitat patches that were identified played an important role in improving connectivity,and the variation rate of connectivity gradually leveled off as the number of new habitats increased.(4)Prioritization of the 25 best new habitat patches increased connectivity from 0.54%to 5.59%as the dispersal distance increased and mainly was located between two Asian elephant distribution regions and two *** of new habitat patches was effective for improving or restoring *** findings can be used as guidance for improving the studied fragmented Asian elephant habitats,and they can also be used as a reference for the habitat restoration of other endangered species heavily affected by habitat fragmentation.

关键词： Asian elephant connectivity habitat restoration habitat suitability landscape graphs

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Groundwater recharge via precipitation in the Badain Jaran Desert,China

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Journal of Groundwater Science and Engineering 2024年第1期12卷 109-118页

作者： Zhe Wang Li-juan Wang Jian-mei Shen Zhen-long Nie Le Cao Ling-qun Meng Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China Technology Innovation center for Geothermal&Hot Dry Rock Exploration and Development Ministry of Natural ResourcesShijiazhuang 050061China

Precipitation infiltration serves as a significant source of groundwater in the Badain Jaran *** investigate variations in precipitation infiltration within the desert,this study collected data on moisture content and temperature from the vadose zone through in-situ field *** these data,a numerical model is employed to explore the mechanism of groundwater recharge via *** results are as follows:(1)Moisture content and temperature in the shallow vadose zone exhibit significant seasonal variations,with moisture content diminishing with increasing depth;(2)Groundwater recharge via precipitation infiltration initially increases and then decreases with groundwater level depth(GWD).Peak groundwater recharge via precipitation occurs at a GWD of 0.75 m,decreasing to merely 0.012 cm at GWDs exceeding 2 m;(3)Groundwater is no longer susceptible to phreatic water evaporation when the GWD reaches approximately 3.7 ***,GWD plays a crucial role in governing groundwater recharge via precipitation in the Badain Jaran Desert.

关键词： Badain Jaran Desert Vadose zone Groundwater recharge In situ monitoring Numerical simulation

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