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Acta Mathematica Scientia 2024年第1期44卷 78-102页

作者：段晓曼关庄丹 School of Mathematics and Statistics Henan UniversityKaifeng475004China Department of Mathematics The University of California at RiversideRiversideCA92521USA

In this article,we study Kahler metrics on a certain line bundle over some compact Kahler manifolds to find complete Kahler metrics with positive holomorphic sectional(or bisectional)***,we apply a strategy to a famou... 详细信息

关键词： Kahler Metrics complete Riemannian metrics open complex manifolds holomorphic bisectional curvature C*bundle almost homogeneous manifolds

Investigation on the influence of vortex generator on particle resuspension

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Particuology 2024年第3期86卷 126-136页

作者： Dongchi Yu Jun-Li Lin Jin-Han Xie ASML 80W Tasman DrSan Jose95134CaliforniaUSA Department of Mechanics and Engineering Science at College of Engineering and State Key Laboratory for Turbulence and Complex Systems Peking UniversityBeijing100081China

The vortex generator(VG)and its well-known effect in flow optimization are widely studied and employed across different engineering ***,while the same working principles of VG may be well suited for the applications on surface-cleaning technologies,such promising potential is hardly,if any,explored in the published ***,in the present study,the influence on flow-induced particle resuspension brought by a rectangular vG in a channel flow is investigated with the help of highfidelity computational fluid dynamics *** increases of particle removal forces and resuspension rates are discovered in long,strip-like regions with reduced boundary-layer thickness resulted from the vG-induced vortices,and the enhancement effect is especially significant for configurations with the VG installed at a greater angle of *** is also shown that while the resuspension enhancements on the lower and the upper surfaces of the channel exhibit distinct statistical characteristics,having a VG in the channel improves the overall particle-removing capability of the channel flow by introducing higher surface-averaged removal forces and particle resuspension *** but not least,the increase of resuspension rate is especially significant for the smaller,micron-scale particles which are otherwise hardly disturbed by a VG-less channel flow,and such resuspension-enhancement effectgenerally subsides with increasing particle size.

关键词： Particle resuspension Vortexgenerator CFD Surface cleaning

Upcycling plastic wastes into value-added products via electrocatalysis and photoelectrocatalysis

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Journal of Energy Chemistry 2024年第4期91卷 522-541页

作者： Sungsoon Kim Dongjae Kong Xiaolin Zheng Jong Hyeok Park Department of Chemical&Biomolecular Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Mechanical Engineering Stanford UniversityStanfordCA 94305USA

Plastic,renowned for its versatility,durability,and cost-effectiveness,is indispensable in modern ***,the annual production of nearly 400 million tons of plastic,coupled with a recycling rate of only 9%,has led to a monumental environmental *** recycling has emerged as a vital response to this crisis,offering sustainable solutions to mitigate its environmental *** these recycling efforts,plastic upcycling has garnered attention,which elevates discarded plastics into higher-value ***,electrocatalytic and photoelectrocatalytic treatments stand at the forefront of advanced plastic *** or photoelectrocatalytic treatments involve chemical reactions that facilitate electron transfer through the electrode/electrolyte interface,dr.ven by electrical or solar energy,*** methods enable precise control of chemical reactions,harnessing potential,current density,or light to yield valuable chemical *** review explores recent progress in plastic upcycling through electrocatalytic and photoelectrocatalytic pathways,offering promising solutions to the plastic waste crisis and advancing sustainability in the plastics industry.

关键词： Plastic upcycling Electrocatalytic reaction Photoelectrocatalytic reaction Value-added product

New evidence for the epigenetic regulation of skeletal stem cells

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Science Bulletin 2024年第13期69卷 2004-2006页

作者： Liming Zhao Jun Xiao Charles K.F.Chan Institute for Stem Cell Biology and Regenerative Medicine Stanford University School of MedicineStanford CA 94305USA Department of Surgery Division of Plastic and Reconstructive SurgeryStanford University School of MedicineStanford CA 94305USA Department of Orthopaedic Surgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Skeletal stem cells(SSCs)are crucial for skeletal development and regeneration,yet the epigenetic regulation of these cells remains poorly *** studies have delineated the epigenetic landscape across the developmental trajectory of SSCs,highlighting the involvement of Ptip in regulating SSC *** skeletal system undergoes dynamic remodeling throughout *** stem cells(SSCs),residing within the skeleton and lineage-restricted,serve as a cellular reserve to foster development and maintain skeletal *** categorized within the broader mesenchymal stromal/stem cells(MSCs).

关键词： skeletal involvement maintain

Iterative Subregion Correction Preconditioners with Adaptive Tolerance for Problems with Geometrically Localized Stiffness

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Communications on Applied Mathematics and Computation 2024年第2期6卷 811-836页

作者： Michael Franco Per-Olof Persson Will Pazner Department of Mathematics University of CaliforniaBerkeleyBerkeleyCA 94720-3840USA Fariborz Maseeh Department of Mathematics and Statistics Portland State UniversityPortlandOR 97201USA

We present a class of preconditioners for the linear systems resulting from a finite element or discontinuous Galerkin discretizations of advection-dominated *** preconditioners are designed to treat the case of geometrically localized stiffness,where the convergence rates of iterative methods are degraded in a localized subregion of the *** convergence may be caused by a number of factors,including the mesh size,anisotropy,highly variable coefficients,and more challenging *** approach taken in this work is to correct well-known preconditioners such as the block Jacobi and the block incomplete LU(ILU)with an adaptive inner subregion *** goal of these preconditioners is to reduce the number of costly global iterations by accelerating the convergence in the stiff region by iterating on the less expensive reduced *** tolerance for the inner iteration is adaptively chosen to minimize subregion-local work while guaranteeing global convergence *** present analysis showing that the convergence of these preconditioners,even when combined with an adaptively selected tolerance,is independent of discretization parameters(e.g.,the mesh size and diffusion coefficient)in the *** demonstrate significant performance improvements over black-box preconditioners when applied to several model convection-diffusion ***,we present performance results of several variations of iterative subregion correction preconditioners applied to the Reynolds number 2.25×10^(6)fluid flow over the NAca 0012 airfoil,as well as massively separated flow at 30°angle of attack.

关键词： Subregion correction Nested Krylov Geometrically localized stiffness

Soluble alpha-synuclein post-translational modifications:unexpected regulators of pathological alpha-synuclein amplification

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Neural Regeneration Research 2024年第5期19卷 959-960页

作者： Simran Kapila Yuhan Sun Chao Peng Shujing Zhang Department of Neurology David Geffen School of MedicineUniversity of CaliforniaLos AngelesCAUSA Molecular Biology Institute Brain Research InstituteMary S.Easton Center for Alzheimer’s ResearchUniversity of CaliforniaLos AngelesCAUSA

The build-up of misfoldedα-synuclein(α-syn)in the central nervous system is the pathological hallmark of a number of neurodegenerative diseases that are known asα-*** include Parkinson’s disease(PD),Parkinson’s disease with dementia(PDD),dementia with Lewy body(LB),multiple system atrophy(MSA),and a subset of Alzheimer’s *** evidence underscores that the intercellular transmission and amplification of pathologicalα-syn are critical processes underlying the progression ofα-synucleinopathies(Peng et al.,2020),and as such,the study of these processes could lead to the identification of promising therapeutics to mitigate disease *** previous studies have focused solely on pathological seeds in relation to disease progression.

关键词： pathological diseases

Deep Energies for Estimating Three-Dimensional Facial Pose and Expression

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Communications on Applied Mathematics and Computation 2024年第2期6卷 837-861页

作者： Jane Wu Michael Bao Xinwei Yao Ronald Fedkiw Department of Computer Science Stanford University353 Jane Stanford WayStanfordCA 94305USA Epic Games 620 Crossroads BlvdCaryNC 27518USA

While much progress has been made in capturing high-quality facial performances using motion capture markers and shape-from-shading,high-end systems typically also rely on rotoscope curves hand-dr.wn on the *** curves are subjective and difficult to dr.w consistently;moreover,ad-hoc procedural methods are required for generating matching rotoscope curves on synthetic renders embedded in the optimization used to determine three-dimensional(3D)facial pose and *** propose an alternative approach whereby these curves and other keypoints are detected automatically on both the image and the synthetic renders using trained neural networks,eliminating artist subjectivity,and the ad-hoc procedures meant to mimic *** generally,we propose using machine learning networks to implicitly define deep energies which when minimized using classical optimization techniques lead to 3D facial pose and expression estimation.

关键词： Numerical optimization Neural networks Motion capture Face tracking

Harness High-Temperature Thermal Energy via Elastic Thermoelectric Aerogels

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Nano-Micro Letters 2024年第8期16卷 196-210页

作者： Hongxiong Li Zhaofu Ding Quan Zhou Jun Chen Zhuoxin Liu Chunyu Du Lirong Liang Guangming Chen College of Materials Science and Engineering Shenzhen UniversityShenzhen 518055People’s Republic of China Department of Bioengineering University of CaliforniaLos AngelesCA 90095USA

Despite notable progress in thermoelectric(TE)materials and devices,developing TE aerogels with high-temperature resistance,superior TE performance and excellent elasticity to enable self-powered high-temperature monitoring/warning in industrial and wearable applications remains a great ***,a highly elastic,flame-retardant and high-temperature-resistant TE aerogel,made of poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/single-walled carbon nanotube(PEDOT:PSS/SWCNT)composites,has been fabricated,displaying attractive compression-induced power factor *** as-fabricated sensors with the aerogel can achieve accurately pressure stimuli detection and wide temperature range ***,a flexible TE generator is assembled,consisting of 25 aerogels connected in series,capable of delivering a maximum output power of 400μW when subjected to a temperature difference of 300 *** demonstrates its outstanding high-temperature heat harvesting capability and promising application prospects for real-time temperature monitoring on industrial high-temperature ***,the designed self-powered wearable sensing glove can realize precise wide-range temperature detection,high-temperature warning and accurate recognition of human hand *** aerogel-based intelligent wearable sensing system developed for firefighters demonstrates the desired self-powered and highly sensitive high-temperature fire warning *** from these desirable properties,the elastic and high-temperature-resistant aerogels present various promising applications including self-powered high-temperature monitoring,industrial overheat warning,waste heat energy recycling and even wearable healthcare.

关键词： Thermoelectrics Aerogel Self-powered High-temperature monitoring High-temperature warning

SRMD:Sparse Random Mode Decomposition

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Communications on Applied Mathematics and Computation 2024年第2期6卷 879-906页

作者： Nicholas Richardson Hayden Schaeffer Giang Tran University of Waterloo WaterlooONCanada University of British Columbia VancouverBCCanada University of california Los AngelesCAUSA

Signal decomposition and multiscale signal analysis provide many useful tools for timefrequency *** proposed a random feature method for analyzing time-series data by constructing a sparse approximation to the *** randomization is both in the time window locations and the frequency sampling,which lowers the overall sampling and computational *** sparsification of the spectrogram leads to a sharp separation between time-frequency clusters which makes it easier to identify intrinsic modes,and thus leads to a new data-dr.ven mode *** applications include signal representation,outlier removal,and mode *** benchmark tests,we show that our approach outperforms other state-of-the-art decomposition methods.

关键词： Sparse random features Signal decomposition Short-time Fourier transform

A REDUCED ORDER SCHWARZ METHOD FOR NONLINEAR MULTIScaLE ELLIPTIC EQUATIONS BASED ON TWO-LAYER NEURAL NETWORKS

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Journal of Computational Mathematics 2024年第2期42卷 570-596页

作者： Shi Chen Zhiyan Ding Qin Li Stephen J.Wright Mathematics Department University of Wisconsin-MadisonMadisonWI 53706USA Department of Mathematics University of California-BerkeleyBerkeley CA 94720USA Mathematics Department and Discovery Institute University of Wisconsin-Madison MadisonWI 53706USA Computer Sciences Department University of WisconsinMadisonWI 53706USA

Neural networks are powerful tools for approximating high dimensional data that have been used in many contexts,including solution of partial differential equations(PDEs).We describe a solver for multiscale fully nonlinear elliptic equations that makes use of domain decomposition,an accelerated Schwarz framework,and two-layer neural networks to approximate the boundary-to-boundarymap for the subdomains,which is the key step in the Schwarz ***,the boundary-to-boundary map requires solution of boundary-value elliptic problems on each *** leveraging the compressibility of multiscale problems,our approach trains the neural network offline to serve as a surrogate for the usual implementation of the boundary-to-boundary *** method is applied to a multiscale semilinear elliptic equation and a multiscale p-Laplace *** both cases we demonstrate significant improvement in efficiency as well as good accuracy and generalization performance.

关键词： Nonlinear homogenization Multiscale elliptic problem Neural networks Do-main decomposition