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Ginzburg-Landau Vortex and Mean Curvature Flow with External Force Field

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Acta Mathematica Sinica,English Series 2006年第6期22卷 1831-1842页

作者： huai yu jian Yan Nan LIU Department of Mathematical Sciences Tsinghua University Beijing 100084 P. R. China

This paper is devoted to the study of the vortex dynamics of the Cauchy problem for a parabolic Ginzburg Landau system which simulates inhomogeneous type II superconducting materials and three-dimensional superconducting thin films having variable thickness. We will prove that the vortex of the problem is moved by a codimension k mean curvature flow with external force field. Besides, we will show that the mean curvature flow depends strongly on the external force, having completely different phenomena from the usual mean curvature flow.

关键词： system of parabolic equations Ginzburg-Landau vortex mean curvature flow

Spacelike Hypersurfaces of Prescribed Gauss-Kronecker Curvature in Exterior Domains

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Acta Mathematica Sinica,English Series 2009年第3期25卷 491-502页

作者： Yong HUANGWuhan huai yu jian Ning SU Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 P. R. China Department of Mathematical Sciences Tsinghua University Beijing 100084 P. R. China nsu@math tsinghua edu. cn

In this paper, we prove an existence theorem for spacelike convex hypersurfaces of prescribed Gauss curvature in Minkowski space.

关键词： Gauss-Kronecker curvature Minkowski space Monge-Ampere type equation

Evolution of hypersurfaces by the mean curvature minus an external force field

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Science China Mathematics 2007年第2期50卷 231-239页

作者： Yan-nan LIU huai-yu jian Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

In this paper, we study the evolution of hypersurface moving by the mean curvature minus an external force field. It is shown that the flow will blow up in a finite time if the mean curvature of the initial surface is larger than some constant depending on the boundness of derivatives of the external force field. For a linear force, we prove that the convexity of the hypersurface is preserved during the evolution and the flow has a unique smooth solution in any finite time and expands to infinity as the time tends to infinity if the initial curvature is smaller than the slope of the force.

关键词： parabolic equation mean curvature flow maximum principle (for tensor) 35K45 53A05

Shoot Apex Demand Determines Assimilate and Nutrients Partitioning and Nutrient-uptake Rate in Tobacco Plants

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Journal of Integrative Plant Biology 2007年第11期49卷 1654-1661页

作者： huai-yu Yang Chun-jian Li Fu-Suo Zhang The Key Laboratory of Plant Nutrition Ministry of Agriculture Key Laboratory of Plant-Soil Interactions Ministry of Education Department of Plant Nutrition China Agricultural University Beijing 100094 China

Our previous experiment revealed that apex-removed plants have larger root systems but a lower K＋-uptake rates than intact tobacco plants. Since the apex is not only a center of growth and metabolism, but also an important place of auxin synthesis and export, the aims of this study were to distinguish whether the apex demand or auxin synthesized in the apex regulates assimilate and nutrients partitioning within plant, and to explain the reason for the lower K＋-uptake rate of the apex-removed plant. In comparison with the control plant, covering the shoot apex with a black transparent plastic bag reduced net increases in dry matter and nutrients; however, the distribution of the dry matter and nutrients between shoot and roots and nutrient-uptake rates were not changed. Removal of the shoot apex shifted the dry mass and nutrients distributions to roots, and reduced the rate of nutrient uptake. Application of 1-naphthylacetic acid （NAA） could partly replace the role of the removed apex, stimulated assimilate and nutrient deposition into the treated tissue, and enhanced the reduced plasma membrane ATPase activity of roots to the control level. However, treatment of the apex-removed plants with NAA could not rescue the reduced nutrient uptake rate and the shifted assimilates and nutrients partitioning caused by excision of the apex. Higher nutrient uptake rate of the intact plants could not be explained by root growth parameters, such as total root surface area and number of root tips. The results from the present study indicate that strong apex demand determined assimilates and nutrients partitioning and nutrient-uptake rate in tobacco （Nicotiana tabacum） plants.

关键词： assimilate and nutrient partitioning auxin nutrient uptake removal of the shoot apex shoot apex demand tobacco (Nicotiana tabacum).

Output Consensus of Heterogeneous Linear MASs via Adaptive Event-Triggered Feedback Combination Control

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IEEE/CAA Journal of Automatica Sinica 2025年第1期12卷 285-287页

作者： Shuo yuan Chengpu yu jian Sun the School of Automation Beijing Institute of Technology the Beijing Institute of Technology Chongqing Innovation Center

Dear Editor,This letter studies output consensus problem of heterogeneous linear multiagent systems over directed graphs. A novel adaptive dynamic event-triggered controller is presented based only on the feedback combination of the agent's own state and neighbors' output,which can achieve exponential output consensus through intermittent communication. The controller is obtained by solving two linear matrix equations, and Zeno behavior is excluded.

关键词： Directed graphs

Towards reliable object representation via sparse directional patches and spatial center cues

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FUNDAMENTAL RESEARCH 2025年第1期5卷 354-359页

作者： jian, Muwei yu, Hui Shandong Univ Finance & Econ Sch Comp Sci & Technol Jinan 250014 Peoples R China Univ Portsmouth Sch Creat Technol Portsmouth 200021 Hants England

In the process of image understanding, the human visual system (HVS) performs multiscale analysis on various objects. HVS primarily focuses on marginally conspicuous image patches located within or around distinct objects rather than scanning the image pixels point by point. Inspired by the HVS mechanism, in this paper, we aimed to describe and exploit multiscale decomposition-based patch detection models for automatic visual feature representation and object localization in images. Our investigation into mimicking and modeling the HVS to capture conspicuous sparse patches and their spatial distribution clues makes a profound contribution to the automatic comprehension and characterization of images by machines. This study demonstrates that the sparse patch-based visual representation with spatial center cues is intrinsically tolerant to object positioning and understanding beyond object variations in spatial position, multiresolution, and chrominance, which has significant implications for many vision-based automatic object grabbing and perception applications, such as robotics, human -machine interaction, and unmanned aerial vehicles (UAVs).

关键词： Multiscale analysis Image patches Visual perception Shearlet transform Object representation

Mechanism of AsperosaponinⅥRelated to EGFR/MMP9/AKT/PI3K Pathway in Treatment of Rheumtoid Arthritis

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Chinese Journal of Integrative Medicine 2025年第2期31卷 131-141页

作者： LUO Jin-fang yu Yang LIU jian-xin School of Basic Medicine Guizhou University of Traditional Chinese MedicineGuiyang(550025)China Sino-Pakistan Center on Traditional Chinese Medicine China-Pakistan International Science and Technology Innovation Cooperation Base for Ethnic Medicine Development in Hunan ProvinceSchool of Pharmaceutical SciencesHunan University of MedicineHuaihua CityHunan Province(418000)China

Objective:To explore the mechanism of action of asperosaponinⅥ(AⅥ)in the treatment of rheumatoid arthritis(RA)and validate it in ex vivo experiments using network pharmacology and molecular docking ***:The predicted targets of AⅥwere obtained from PharmMaper,UniProt and Swiss Target Prediction platforms,the disease targets were collected from Online Mendelian Inheritance in Man,Therapeutic Target Database and Gene Cards databases,the intersection targets of AⅥand RA were obtained from Venny 2.1.0,and the protein-protein interaction(PPI)network was obtained from STRING database,which was analyzed by Cytoscape software and screened to obtain the core *** software was used to analyze PPI network and screen the core *** on the Database for Annotation,Visualization and Integrated Discovery database,Gene Ontology functional and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed,and Cytoscape software was used to construct the"DiseasePathway-Target-Drug"network,which was finally verified by molecular docking and animal ***:Network pharmacological studies showed that AⅥwas able to modulate 289 targets,with 102 targets for the potential treatment of RA,with the core pathway being the AKT/PI3K signaling pathway,and the core targets being the epidermal growth factor receptor(EGFR)and matrix metalloproteinase 9(MMP9).Molecular docking results showed that AⅥcould produce strong binding with both of the 2 core *** vitro cellular experiments showed that AⅥreduced nitric oxide,prostaglandin E_2,tumor necrosis factor-alpha(TNF-α),interleukin-6(IL-6),and IL-1βlevels(P<0.05)and inhibited cyclooxygenase-2,nitric oxide synthase,EGFR,MMP9,phosphorylated phosphoinositide 3-kinase(p-PI3K),and phosphorylated serine-threonine kinase(p-AKT)proteins(P<0.05).The results of in vivo studies showed that AⅥimproved RA score and foot swelling thickness and decreased TNF-α,IL-6,p-PI3K and p-AKT levels in RA rat

关键词： inflammation rheumatoid arthritis network pharmacology asperosaponinⅥ EGFR/MMP9/AKT/PI3K pathway

Ideal Bi‑Based Hybrid Anode Material for Ultrafast Charging of Sodium‑Ion Batteries at Extremely Low Temperatures

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Nano-Micro Letters 2025年第3期17卷 152-167页

作者： Jie Bai jian Hui Jia yu Wang Chun Cheng Yang Qing jiang Key Laboratory of Automobile Materials(Jilin University) Ministry of EducationSchool of Materials Science and EngineeringJilin UniversityChangchun 130022People’s Republic of China

Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or ***,the key capability of ultrafast charging at ultralow temperature for SIBs is rarely ***,a hybrid of Bi nanoparticles embedded in carbon nanorods is demonstrated as an ideal material to address this issue,which is synthesized via a high temperature shock *** a hybrid shows an unprecedented rate performance(237.9 mAh g^(−1) at 2 A g^(−1))at−60℃,outperforming all reported SIB anode *** with a Na_(3)V_(2)(PO_(4))_(3)cathode,the energy density of the full cell can reach to 181.9 Wh kg^(−1) at−40°*** on this work,a novel strategy of high-rate activation is proposed to enhance performances of Bi-based materials in cryogenic conditions by creating new active sites for interfacial reaction under large current.

关键词： Bi nanoparticles High temperature shock High-rate activation Ultrafast charging Low-temperature sodium-ion batteries

Hyperbranched Poly(α-aminonitrile)s Constructed via Catalyst-Free Multicomponent Polymerization of Trialdehydes,Diamines and Trimethylsilyl Cyanide

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Chinese Journal of Polymer Science 2025年第2期43卷 341-349页

作者： Tian-yu Cheng jian-Qing Ding yu-Xin Tong Jun-Guo Fang Jia Wang School of Chemical and Environmental Engineering Anhui Polytechnic UniversityWuhu241000China Songshan Lake Materials Laboratory Dongguan523808China

Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse ***,the development of simple and efficient reactions to prepare hyperbranched polymers is of great *** this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological ***,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high *** work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.

关键词： Catalyst-free Multicomponent polymerization Hyperbranched polymer Post-polymerization