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

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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OPTIMUM ORDERING POLICY FOR PREVENTIVE AGE REPLACEMENT

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Journal of Systems Science and Systems Engineering 2009年第3期18卷 283-291页

作者： young T. park Jing sun Department of Systems Management Engineering Sungkyunkwan University School of Economics and Management Tsinghua University Beijing 100084 China

Most of the spare ordering policies treated up to now have assumed that preventive and corrective replacement costs are equal, which implies in essential that there is no significant need for preventive replacement. This paper presents an ordering policy for preventive age replacement with minimal repair. Introducing the replacement, repair, inventory holding and shortage costs, the expected cost rate is derived. A procedure to determine jointly the ordering time for a spare and the preventive replacement time for the operating unit so as to minimize the expected cost rate is proposed. To explain the ordering policy and the optimization procedure, a numerical example is also included.

关键词： Ordering policy spare age replacement minimal repair

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Martensite decomposition under thermal-mechanical coupling conditions to fabricate an ultrafine-grained Ti6Al4Mo4Zr1W0.2Si alloy

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Journal of Materials Science & Technology 2024年第1期168卷 157-168页

作者： Taoyu Zhou Jiuxu Yang Nan Li Hao sun Bohua Zhang Zibo Zhao Qingjiang Wang Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The fabrication of ultrafine-grained microstructures(grain size below 1μm)in titanium alloys is beneficial for improving their mechanical properties at room temperature and medium tempera-tures(400-550°C).However,a long-standing challenge involves the low-cost manufacturing of bulk ultrafine-grained titanium *** this work,we developed a facile strategy through martensite de-composition at thermal-mechanical coupling conditions,to fabricate an equiaxed microstructure in a Ti6Al4Mo4Zr1W0.2Si model alloy with an averageαgrain size of 315±62 *** formation of the ultrafine-grained microstructure was because the lattice strain stored in the martensitic initial mi-crostructure enhanced the nucleation rate of dynamic recrystallization,meanwhile,the pinning role of martensite decomposition productsβand(Ti,Zr)_(5)Si_(3)phases suppressed grain coarsening at high *** to conventional(α+β)alloys,the tensile strength of this alloy improved by 20%-30%at both room temperature and 550°C,without decreasing its *** situ SEM observations revealed that the ultrafine-grained microstructure would not only suppress dislocation motions but also contribute to the homogenous deformation in the matrix of the material,therefore,it resulted in higher mechanical *** research results may be of great significance to the development of next-generation aviation titanium alloys.

关键词： Ultrafine-grained Titanium alloy In situ observation Deformation mechanism Thermostability

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Three-dimensional stability calculation method for high and large composite slopes formed by mining stope and inner dump in adjacent open pits

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International Journal of Mining Science and Technology 2024年第4期34卷 507-520页

作者： Zuchao Liang Dong Wang Guanghe Li Guangyu sun Mingyu Yu Dong Xia Chunjian Ding College of Mining Engineering Liaoning Technical UniversityFuxin 123000China Inner Mongolia Pingxi Baiyinhua Coal Industry Co. Ltd.Xilingol League 026000China Guoneng Baorixile Energy Co. Ltd.Hulunbuir 021008China

The 2D limit equilibrium method is widely used for slope stability ***,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical ***,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope *** the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding *** integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is ***,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is *** analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear *** spatial form equation of the sliding mass comprises an ellipsoid and weak plane *** analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite ***,the3D stability coefficient of the composite slope exhibits an exponential co

关键词： Composite slope Destabilization mechanism 3D mechanical effect Three-dimensional stability Coordinated development distance

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Quantum dot-enabled infrared hyperspectral imaging with single-pixel detection

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Light(Science & Applications) 2024年第6期13卷 1112-1121页

作者： Heyan Meng Yuan Gao Xuhong Wang Xianye Li Lili Wang Xian Zhao Baoqing sun School of Information Sciences and Engineering Shandong UniversityQingdaoChina Center for Optics Research and Engineering(CORE) Key Laboratory of Laser&Infrared System(Shandong University)Ministry of EducationShandong UniversityQingdaoChina School of Mechanical Electrical and Information EngineeringShandong UniversityWeihaiChina

Near-infrared(NIR)hyperspectral imaging is a powerful technique that enables the capture of three-dimensional(3D)spectra-spatial information within the NIR spectral range,offering a wide array of ***,the high cost associated with InGaAs focal plane array(FPA)has impeded the widespread adoption of NIR hyperspectral *** this challenge,in this study,we adopt an alternative approach—single-pixel detection for NIR hyperspectral *** investigation reveals that single-pixel detection outperforms conventional FPA,delivering a superior signal-to-noise ratio(SNR)for both spectral and imaging *** implement this strategy,we leverage self-assembled colloidal quantum dots(CQDs)and a digital micromirror device(DMD)for NIR spectral and spatial information multiplexing,complemented by single-pixel detection for simultaneous spectral and image *** experimental results demonstrate successful NIR hyperspectral imaging with a detection window about 600 nm and an average spectral resolution of 8.6 nm with a pixel resolution of 128×*** resulting spectral and spatial data align well with reference instruments,which validates the effectiveness of our *** circumventing the need for expensive and bulky FPA and wavelength selection components,our solution shows promise in advancing affordable and accessible NIR hyperspectral imaging technologies,thereby expanding the range of potential applications.

关键词： spectral Quantum mirror

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Multi-Material magnetic field-assisted additive manufacturing system for flexible actuators with programmable magnetic arrangements

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Frontiers of Mechanical Engineering 2024年第2期19卷 109-120页

作者： Yujie HUANG Haonan sun Chengqian ZHANG Ruoxiang GAO Hongyao SHEN Peng ZHAO The State Key Laboratory of Fluid Power and Mechatronic Systems College of Mechanical EngineeringZhejiang UniversityHangzhou 310027China The Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province College of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Center for X-Mechanics Department of Engineering MechanicsZhejiang UniversityHangzhou 310027China

Manufacturing flexible magnetic-driven actuators with complex structures and magnetic arrangements to achieve diverse functionalities is becoming a popular *** various manufacturing technologies,magnetic-assisted digital light processing(DLP)stands out because it enables precise manufacturing of macro-scale structures and micro-scale distributions with the assistance of an external magnetic *** research on manufacturing magnetic flexible actuators mostly employs single materials,which limits the magnetic driving performance to some *** on these characterizations,we propose a multi-material magnetic field-assisted DLP technology to produce flexible actuators with an accuracy of 200μ*** flexible actuators are printed using two materials with different mechanical and magnetic *** the interface connectivity of multi-material printing,the effect of interfaces on mechanical properties is also *** results indicate good chemical affinity between the two materials we *** overlap or connection length of the interface moderately improves the tensile strength of multi-material *** addition,we investigate the influence of the volume fraction of the magnetic part on *** and experimental results indicate that increasing the volume ratio(20%to 50%)of the magnetic structure can enhance the responsiveness of the actuator(more than 50%).Finally,we successfully manufacture two multi-material flexible actuators with specific magnetic arrangements:a multi-legged crawling robot and a flexible gripper capable of crawling and grasping *** results confirm that this method will pave the way for further research on the precise fabrication of magnetic flexible actuators with diverse functionalities.

关键词： multi-material magnetic field-assisted manufacturing digital light processing flexible actuators magnetic arrangement

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Scale effect removal and range migration correction for hypersonic target coherent detection

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Journal of Systems Engineering and Electronics 2024年第1期35卷 14-23页

作者： WU Shang sun Zhi JIANG Xingtao ZHANG Haonan DENG Jiangyun LI Xiaolong CUI Guolong School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

The detection of hypersonic targets usually confronts range migration(RM)issue before coherent integration(CI).The traditional methods aiming at correcting RM to obtain CI mainly considers the narrow-band radar ***,with the increasing requirement of far-range detection,the time bandwidth product,which is corresponding to radar’s mean power,should be promoted in actual ***,the echo signal generates the scale effect(SE)at large time bandwidth product situation,influencing the intra and inter pulse integration *** eliminate SE and correct RM,this paper proposes an effective algorithm,i.e.,scaled location rotation transform(ScLRT).The ScLRT can remove SE to obtain the matching pulse compression(PC)as well as correct RM to complete CI via the location rotation transform,being implemented by seeking the actual rotation *** to the traditional coherent detection algorithms,Sc LRT can address the SE problem to achieve better detection/estimation *** last,this paper gives several simulations to assess the viability of ScLRT.

关键词： hypersonic target detection coherent integration(CI) scale effect(SE)removal range migration(RM)correction scaled location rotation transform(ScLRT)

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Anomalous bond lengthening in compressed magnetic doped semiconductor Ba(Zn_(0.95)Mn_(0.05))_(2)As_(2)

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Journal of Semiconductors 2024年第4期45卷 36-41页

作者： Fei sun Yi Peng Guoqiang Zhao Xiancheng Wang Zheng Deng Changqing Jin Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physics University of Chinese Academy of SciencesBeijing 101408China Center for High Pressure Science and Technology Advanced Research Beijing 100094Chin

Applying pressure has been evidenced as an effective method to control the properties of semiconductors,owing to its capability to modify the band configuration around Fermi ***,structural evolutions under external pres-sures are required to analyze the *** high-pressure structure of a magnetic doped semiconductor Ba(Zn_(0.95)Mn_(0.05))_(2)As_(2)is studied with combination of in-situ synchrotron X-ray diffractions and diamond anvil *** materials become ferromagnetic with Curie temperature of 105 K after further 20%K *** title material undergoes an isostruc-tural phase transition at around 19 *** the transition pressure,it is remarkable to find lengthening of Zn/Mn-As bond within Zn/MnAs layers,since chemical bonds are generally shortened with applying *** with the bond stretch,interlayer As-As distances become shorter and the As-As dimers form after the phase *** further compres-sion,Zn/Mn-As bond becomes shortened due to the recovery of isotropic compression on the Zn/MnAs layers.

关键词： magnetic semiconductor high-pressure in-situ X-ray diffraction phase transition

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Sex-specific facilitation and reproduction of the gynodioecious cushion plant Arenaria polytrichoides on the Himalaya-Hengduan mountains,SW China

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Plant Diversity 2024年第2期46卷 247-255页

作者： Xufang Chen Yazhou Zhang Lishen Qian Renyu Zhou Hang sun Jianguo Chen State Key Laboratory of Plant Diversity and Specialty Crops Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnanChina Yunnan Key Laboratory of Plateau Wetland Conservation Restoration and Ecological ServicesSouthwest Forestry UniversityKunmingYunnanChina

When benefiting other beneficiaries,cushion plants may reciprocally receive feedback *** feedback effects on different sex morphs,however,remains *** this study,taking the gynodioecious Arenaria polytrichiodes as a model species,we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio,and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover *** total beneficiary cover ratio was similar between females and *** produced much less flowers but more fruits than *** results suggested that females and hermaphrodites possess similar facilitation intensity,and female cushion *** may allocate more resources saved from pollen production to seed production,while hermaphrodites possibly allocate more resources to pollen production hence reducing seed *** surface areas covered by beneficiaries produced less flowers and fruits than areas without *** addition,strong negative correlations between beneficiary cover and flower cover were detected for both females and hermaphrodites,but the correlation strength were similar for these two sex ***,the correlation between beneficiary cover and fruit cover was only significantly negative for females,suggesting that beneficiary plants negatively affect fruit reproduction of females while have neutral effects on *** the results suggest that to facilitate other beneficiaries can induce reproductive costs on cushion ***,with females possibly suffering greater cost than *** differentiation in reproductive costs between sex morphs,in long-term perspective,may imply sex imbalance in population dynamics.

关键词： Facilitation intensity Feedback effect Sex-specific facilitation Nurse plant Population dynamics Reproductive function

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Large-area ultrastrong and stiff aramid nanofiber based layered nanocomposite films

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Nano Research 2024年第2期17卷 829-835页

作者： Zhidong Nie Yingzhi sun Tianxu Zhou Shengwen Kong Linxing Liu Chuangqi Zhao Mingjie Liu Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China University of Science and Technology of China Hefei 230026China Suzhou Institute for Advanced Research University of Science and Technology of ChinaSuzhou 215123China International Research Institute for Multidisciplinary Science Beihang UniversityBeijing 100191China

One-dimensional(1D)aramid nanofiber(ANF)based nanocomposite films have drawn increasing attentions in various applications due to their excellent mechanical properties and impressive chemical and thermal ***,the large-area fabrication of aramid nanocomposite films with ultrastrong mechanical properties under mild conditions remains a great *** we present a facile superspreading-assisted strategy to produce aramid nanofiber based oriented layered nanocomposites using phase inversion process that occurs at the fully swollen hydrogel *** nanocomposite films based on ANF,carboxylation carbon tube(CNT–COOH),poly(vinyl alcohol)(PVA),and MXene nanosheet exhibit a tensile strength of up to 870.8±85 MPa,a young’s modulus of 21.8±2.2 GPa,and outstanding toughness(up to 43.2±4.6 MJ/m^(3)),which are much better than those conventional aramid nanofiber based *** conductivity of our nanocomposite films reaches the maximum of about 1100 S/*** fabulous mechanical properties combination and continuous production capability render our strategy representing a promising direction for the development of high-performance nanocomposites.

关键词： aramid nanofibers MXene nanosheets nanocomposites ultrastrong and stiff superspreading large-area production

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