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Fractional order distance regularized level set method with bias correction

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 64-82页

作者： Cai Xiumei He Ningning Wu Chengmao liu xiao liu Hang School of Automation Xi'an University of Posts and TelecommunicationsXi'an 710121China School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

The existing level set segmentation methods have drawbacks such as poor convergence,poor noise resistance,and long iteration *** this paper,a fractional order distance regularized level set segmentation method with bias correction is *** method firstly introduces fractional order distance regularized term to punish the deviation between the level set function(LSF)and the signed distance *** a series of covering template is constructed to calculate fractional derivative and its conjugate of image *** introducing the offset correction term and fully using the local clustering property of image intensity,the local clustering criterion of image intensity is defined and integrated with the neighborhood center to obtain the global criterion of image ***,the fractional distance regularization,offset correction,and external energy constraints are combined,and the energy optimization segmentation method for noisy image is established by level *** results show that the proposed method can accurately segment the image,and effectively improve the efficiency and robustness of exiting state of the art level set related algorithms.

关键词： image segmentation fractional order distance regularization level set function fractional derivative bias correction

Impacts of Water-Sediment Regulation Scheme on Chromophoric Dissolved Organic Matter in the Lower Yellow River

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Journal of Ocean University of China 2024年第2期23卷 455-466页

作者： liu xiao JIANG Xueyan liu Qian SUI Juanjuan ZOU Li Key Laboratory of Marine Chemistry Theory and Technology of Ministry of Education Ocean University of ChinaQingdao 266100China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China School of Earth Sciences University of BristolBristolBS81RJUK North China Sea Environmental Monitoring Center State Oceanic AdministrationQingdao 266033China Key Laboratory of Ecological Prewarning Protection and Restoration of Bohai SeaMinistry of Natural ResourcesQingdao 266033China Key Laboratory of Marine Environment and Ecology of Ministry of Education Ocean University of ChinaQingdao 266100China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China

As a river with more than 3000 reservoirs in its watershed,the Yellow River has been affected by dams not only on the sediment load,but also on the water ***-sediment regulation scheme(WSRS),which has been carried out annually in the Yellow River since 2002,is a typical human activity affecting river water *** dissolved organic matter(CDOM)in river is susceptible to changes in ecological and environmental conditions as well as human ***,we report variations in dissolved organic carbon concentrations,compositions and sources of CDOM in time series samples in the lower Yellow River during *** addition,a parallel factor fluorescence analysis(PARAFAC)method is applied to identify different fluorescent components in water samples during WRSR,showing four major components including tryptophan-like component(C1),microbial humic-like component(C2),terrestrial humic-like component(C3)and tyrosine-like component(C4).In general,C1 increased after water regulation,while C2 and C3 increased after sediment regulation,indicating that the water and sediment released by the dam have different effects on CDOM *** the impacts of the dam,source of CDOM in the lower Yellow River is mainly autochthonous related to microbial activities,and is regulated by the terrestrial input during WSRS *** resuspension inhibits microbial activities and reduces the production of autochthonous ***,human activities especially WSRS,as exemplified here,significantly alter the quality and quantity of CDOM in the lower Yellow River,affecting CDOM dynamics and biogeochemical processes in the estuarine environment.

关键词： chromophoric dissolved organic matter(CDOM) water-sediment regulation scheme(WSRS) Yellow River optical properties

Novel stacking models based on SMOTE for the prediction of rockburst grades at four deep gold mines

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Underground Space 2024年第6期19卷 169-188页

作者： Peng xiao Zida liu Guoyan Zhao Pengzhi Pan State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China School of Resources and Safety Engineering Central South UniversityChangsha 410083China

Rockburst is a frequently encountered hazard during the production of deep gold *** prediction of rockburst is an important measure to prevent rockburst in gold *** study considers seven indicators to evaluate rockburst at four deep gold *** research and rock tests were performed at two gold mines in China to collect these seven indicators and rockburst *** collected database was oversampled by the synthetic minority oversampling technique(SMOTE)to balance the categories of rockburst *** models combining tree-based models and logistic regression(LR)were established by the balanced *** datasets from another two deep gold mines were implemented to verify the applicability of the predictive *** stacking model combining extremely randomized trees and LR based on SMOTE(SMOTE-ERT-LR)was the best model,and it obtained a training accuracy of 100%and an evaluation accuracy of 100%.Moreover,model evaluation suggested that SMOTE can enhance the prediction performance for weak rockburst,thereby improving the overall ***,sensitivity analysis was performed for *** results indicated that the SMOTE-ERT-LR model can achieve satisfactory performance when only depth,maximum tangential stress index,and linear elastic energy index were available.

关键词： Rockburst prediction Gold mine Stacking model SMOTE

Rbm8a regulates neurogenesis and reduces Alzheimer's disease-associated pathology in the dentate gyrus of 5×FAD mice

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Neural Regeneration Research 2024年第4期19卷 863-871页

作者： Chenlu Zhu xiao Ren Chen liu Yawei liu Yonggang Wang Department of Neurology Lanzhou University Second Hospital Department of Neurology The First Affiliated Hospital of Nanchang University Department of Neurology Xiaogan City Central Hospital Health Service Department of the Guard Bureau of the General Office of the Central Committee of the Communist Party of China Headache Center Department of NeurologyBeijing Tiantan HospitalCapital Medical University

Alzheimer’s disease is a prevalent and debilitating neurodegenerative condition that profoundly affects a patient’s daily functioning with progressive cognitive decline,which can be partly attributed to impaired hippocampal *** in the hippocampal dentate gyrus is likely to persist throughout life but declines with aging,especially in Alzheimer’s *** evidence indicated that RNA-binding protein 8A(Rbm8a)promotes the proliferation of neural progenitor cells,with lower expression levels observed in Alzheimer’s disease patients compared with healthy *** study investigated the hypothesis that Rbm8a overexpression may enhance neurogenesis by promoting the proliferation of neural progenitor cells to improve memory impairment in Alzheimer’s ***,Rbm8a overexpression was induced in the dentate gyrus of 5×FAD mice to validate this *** Rbm8a levels in the dentate gyrus triggered neurogenesis and abated pathological phenotypes(such as plaque formation,gliosis reaction,and dystrophic neurites),leading to ameliorated memory performance in 5×FAD *** sequencing data further substantiated these findings,showing the enrichment of differentially expressed genes involved in biological processes including neurogenesis,cell proliferation,and amyloid protein *** conclusion,overexpressing Rbm8a in the dentate gyrus of 5×FAD mouse brains improved cognitive function by ameliorating amyloid-beta-associated pathological phenotypes and enhancing neurogenesis.

关键词： Adora2a Alzheimer’s disease astrocyte cAMP signaling pathway dentate gyrus dystrophic neurites microglia neurogenesis plaque Rbm8a

Revolution in thermoelectric cooling using PbSe thermoelectrics by grid plainification

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Science China Materials 2024年第5期67卷 1672-1673页

作者： xiao-Lei Shi Qingfeng liu Zhi-Gang Chen School of Chemistry and Physics ARC Research Hub in Zero-emission Power Generation for Carbon Neutralityand Centre for Materials ScienceQueensland University of TechnologyBrisbaneQueensland4000Australia State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing211816China

Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].Howev... 详细信息

关键词： enable thermoelectric constrained

An efficient stiffness analysis model based on shear deformation theory for flexible skin shear variable-sweep wing

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Chinese Journal of Aeronautics 2024年第10期37卷 445-458页

作者： Yue BAI Guang YANG Hong xiao Hongwei GUO Rongqiang liu Bei liu State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China China Aerodynamics Research and Development Center Institute of High-Speed AerodynamicsMianyang 621000China

Fixed-wing aircraft cannot maintain optimal aerodynamic performance at different flight *** a type of morphing aircraft,the shear variable-sweep wing(SVSW)can dramatically improve its aerodynamic performance by altering its shape to adapt to various flight *** order to achieve smooth continuous shear deformation,SVSW’s skin adopts a flexible composite skin design instead of traditional aluminum alloy ***,this also brings about the non-linear difficulty in stiffness modeling and *** this research,a new SVSW design and efficient stiffness modeling method are *** on shear deformation theory,the flexible composite skin is equivalently modeled as diagonally arranged nonlinear springs,simulating the elastic force interaction between the skin and the *** shear loading tests of flexible composite skin,the accuracy of this flexible composite skin modeling method is *** SVSW stiffness model was established,and its accuracy was verified through static loading *** effects of root connection,sweep angles,and flexible composite skin on the SVSW stiffness are ***,considering three typical flight conditions of SVSW:low-speed flow(Ma=0.3,Re=5.8210^(6)),transonic flow(Ma=0.9,Re=3.4410^(6)),and supersonic flow(Ma=3,Re=7.5110^(6)),the stiffness characteristics of SVSW under flight conditions were *** calculated results guide the application of SVSW.

关键词： Shear variable-sweep wing(SVSW) Flexible composite skin Morphing mechanism Stiffness analysis Loading tests Structure

A lightweight and high compressive resistance thermal insulation material with dual-network structure

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Nano Research 2024年第5期17卷 4279-4287页

作者： Mengmeng Yang Zhaofeng Chen Yang Ding Wu qiong Tianlong liu Manna Li Lixia Yang Sheng Cui School of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech UniversityNanjing 211816China

Ceramic fibrous aerogels are highly desirable for thermal management materials due to their high porosity,excellent elasticity,thermal conductivity,and good thermal ***,the fabrication of nanofibrous aerogel with super-elasticity and good shape retention at the same time has remained *** meet the requirements,a novel anisotropy nanofibrous-granular aerogel with a quasi-layered multi-arch-like and hierarchical-cellular structure is designed and prepared by vacuum-filtration-assisted freeze-drying and *** quasi-layered multi-arch and flexible nanofibers endowed the aerogels with excellent mechanical robustness(ultimate stress up to 60 kPa with strain 60%)and super-elasticity with recoverable compression strain up to 60%.The introduced SiO_(2) aerogel nanoparticles and nanofibers are assembled into an arch-like structure and become the connection point of adjacent nanofibers,which endows low thermal conductivity(0.024 mW/(m·K))of composite *** novel strategy provides a fresh perspective for the preparation of nanofibrous aerogel with robust mechanical in thermal insulation and other fields.

关键词： nanofibrous aerogel dual-network structure thermal insulation nanofibrous-granular composite aerogels strong mechanical

Top priority current path between SiC particles during ultra-high temperature flash sintering: Presence of PyC “bridges”

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Journal of Advanced Ceramics 2024年第2期13卷 255-262页

作者： Le Lu Tianlong liu Zhaofeng Chen Fei Wang Mengmeng Yang qiong Wu Lixia Yang Huanyong Li International Laboratory for Insulation and Energy Efficiency Materials College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 211106China State Key Laboratory of Solidification Processing School of Materials and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

Flash sintering(FS)is a novel technique for rapidly densifying silicon carbide(SiC)*** work achieved a rapid sintering of SiC ceramics by the utilization of ultra-high temperature flash sintering within 60 *** carbon(PyC)“bridges”were constructed between SiC particles through the carbonisation of phenolic resin,providing a large number of current *** incubation time of the flash sintering process was significantly reduced,and the sintering difference between the centre and the edge regions of the ceramics was minimized,with an average particle size of the centre region and edge region being 12.31 and 9.02μm,*** results showed that the porosity of the SiC ceramics after the flash sintering was reduced to 14.79% with PyC“bridges”introduced,and the Vickers hardness reached 19.62 ***“bridges”gradually evolved from amorphous eddy current carbon to oriented graphite carbon,indicating that the ultra-high temperature environment in which the sample was located during the flash sintering was successfully ***-high temperature flash sintering of SiC is expected to be applied to the local repair of matrix damage in SiC ceramic matrix composites.

关键词： silicon carbide(SiC) flash sintering(FS) pyrolytic carbon(PyC)"bridges" current path instantaneous

Recent advances in vacancy engineering for reliable lithiumsulfur batteries

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Rare Metals 2024年第2期43卷 455-477页

作者： Wen-Dong liu xiao Tang Jun-An Feng Chao-Yue Zhang Hao liu Chuan Shi xiao-Xian Zhao Jian-Jun Song College of Physics School of Chemistry and Chemical EngineeringQingdao UniversityQingdao266071China Faculty of Science Centre for Clean Energy TechnologySchool of Mathematical and Physical SciencesUniversity of Technology SydneySydneyNSW2007Australia Department of Chemistry College of ScienceHebei Agricultural UniversityBaoding071001China

The high-energy-density and low-cost features endow lithium-sulfur batteries with broad application ***,many drawbacks,especially the detrimental shuttle effect,have hindered the further development of *** response,a lot of new structures have been applied to suppress the shuttle effect and promote the development of ***,vacancy engineering has gained the attention of researchers due to its unique electronic *** review aims to analyze the application of vacancy engineering in ***,the electrochemistry of LSBs has been systematically discussed and the existing challenges as well as improvement tactics of LSBs have also been ***,the preparation methods and characterization technologies of various vacancies are summarized,including oxygen vacancies,sulfur vacancies,selenium vacancies,other anion vacancies,cation vacancies,*** latest applications of vacancy engineering in LSBs are also summarized in this ***,some prospects and insights for further investigation and practical application of vacancy engineering in LSBs are put forward.

关键词： Lithium-sulfur batteries(LSBs) Defects Vacancy engineering Electronic structure Shuttle effect