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(1+2)-Dimensional Radially Symmetric Wave Maps Revisit

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Chinese Annals of Mathematics,Series B 2022年第5期43卷 785-796页

作者： yi zhou School of Mathematical Sciences Fudan UniversityShanghai 200433China

The author gives an alternative and simple proof of the global existence of smooth solutions to the Cauchy problem for wave maps from the(1+2)-dimensional Minkowski space to an arbitrary compact smooth Riemannian manifold without boundary, for arbitrary smooth, radially symmetric data. The author can also treat non-compact manifold under some additional assumptions which generalize the existing ones.

关键词： Cauchy problem Wave maps Global smooth solution

Generalized Persistence of Entropy Weak Solutions for System of Hyperbolic Conservation Laws

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Chinese Annals of Mathematics,Series B 2022年第4期43卷 499-508页

作者： yi zhou School of Mathematical Sciences Fudan UniversityShanghai 200433China

Let u(t,x)be the solution to the Cauchy problem of a scalar conservation law in one space *** is well known that even for smooth initial data the solution can become discontinuous in finite time and global entropy weak solution can best lie in the space of bounded total *** is impossible that the solutions belong to,for example,H^(1) because by Sobolev embedding theorem H^(1) functions are Holder ***,the author notes that from any point(t,x),he can draw a generalized characteristic downward which meets the initial axis at y=α(t,x).If he regards u as a function of(t,y),it indeed belongs to H^(1) as a function of y if the initial data belongs to H^(1).He may call this generalized persistence(of high regularity)of the entropy weak *** main purpose of this paper is to prove some kinds of generalized persistence(of high regularity)for the scalar and 2×2 Temple system of hyperbolic conservation laws in one space dimension.

关键词： Quasilinear hyperbolic system Cauchy problem Entropy weak solution Vanishing viscosity method

Ultrasonic enhancement of persulfate oxidation system governs emerging pollutants decontamination

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Green Energy & Environment 2024年第11期9卷 1666-1678页

作者： Yanpan Li Yanbo zhou yi zhou National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical ProcessEast China University of Science and Technology130 Meilong RoadShanghai200237China Shanghai Engineering Research Center for Multi-media Environmental Catalysis and Resource Utilization East China University of Science and Technology130 Meilong RoadShanghai200237China Shanghai Institute of Pollution Control and Ecological Security Shanghai200092China

Emerging contaminants (ECs) are widely present in aquatic environments, posing potential risks to both ecosystems and human health. Theultrasound-assisted persulfate oxidation process has attracted considerable attention in the degradation of ECs due to its ability to generate bothsulfate radicals and cavitation effects, enhancing degradation effects. In this paper, the principle of ultrasonic synergistic Fenton-like oxidationsystem for degrading organic pollutants was reviewed, divided into homogeneous system, non-homogeneous system, and single-atom system toexplore the synergistic effect of ultrasound-enhanced persulfate technology in three aspects, and the effects of environmental factors such asultrasonic frequency and power, system pH, temperature, and initial oxidant concentration on the system's decontamination performance werediscussed. Finally, future research on ultrasonically activated persulfate technology is summarized and prospected.

关键词： Ultrasound Persulfate Emerging contaminants Reaction mechanism Synergistic effects

LOCAL EXISTENCE THEOREM FOR FIRST ORDER SEMILINEAR HYPERBOLIC SYSTEMS IN SEVERAL SPACE DIMENSIONS

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Chinese Annals of Mathematics,Series B 1997年第2期18卷 223-232页

作者： zhou yi Institut of Mathematics Fudan UniversityShanghai 200433China.

This paper studies first order semilinear hyperbolic systems in n(n≥2)space *** the hypothesis that the system satisfies so called`null condition',the local well posedness for its Cauchy problem with initial data in ... 详细信息

关键词： Semilinear hyperbolic systems Local well posedness Cauchy problem

A Class of Large Solutions to the 3D Incompressible MHD and Euler Equations with Damping

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Acta Mathematica Sinica,English Series 2018年第1期34卷 63-78页

作者： yi zhou yi ZHU School of Mathematical Sciences Fudan University

In this paper, we derive the global existence of smooth solutions of the 3D incompressible Euler equations with damping for a class of large initial data, whose Sobolev norms H8 can be arbitrarily large for any s ≥0. The approach is through studying the quantity representing the difference between the vortieity and velocity. And also, we construct a family of large solutions for MHD equations with damping.

关键词： Large solutions euler equations MHD equations damping

Field measurements for calibration of simplified models of the stiffening effect of infill masonry walls in high-rise RC framed and shear-wall buildings

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Earthquake Engineering and Engineering Vibration 2020年第1期19卷 87-104页

作者： zhou Yun Pei yilin zhou yi Hyeon-Jong Hwang yi Weijian College of Civil Engineering Hunan UniversityChangsha 410082China Hunan Provincial Key Lab on Damage Diagnosis for Engineering Structures Hunan UniversityChangsha 410082China Key Laboratory for Green&Advanced Civil Engineering Materials and Application Technology of Hunan Province Hunan UniversityChangsha 410082China

As a type of nonstructural component, infill walls play a significant role in the seismic behavior of high-rise buildings. However, the stiffness of the infill wall is generally either ignored or considered by simplified empirical criteria that lead to a period shortening. The difference can be greatly decreased by using a structural identification methodology. In this study, an ambient vibration test was performed on four on-site reinforced concrete high-rise buildings, and the design results were compared with the PKPM models using corresponding finite element(FE) models. A diagonal strut model was used to simulate the behavior of the infill wall, and the identified modal parameters measured from the on-site test were employed to calibrate the parameters of the diagonal strut in the FE models. The SAP2000 models with calibrated elastic modulus were used to evaluate the seismic response in the elastic state. Based on the load-displacement relationship of the infill wall, nonlinear dynamic analysis models were built in PERFORM-3 D and calibrated using the measured modal periods. The analysis results revealed that the structural performance under small/large earthquake records were both strengthened by infill walls, and the contribution of infill walls should be considered for better accuracy in the design process.

关键词： high-rise building ambient vibration test model calibration infi ll wall seismic performance nonlinear dynamic analysis

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扭曲双层石墨烯的层间电导特性研究

原子与分子物理学报 2025年第6期42卷 83-88页

作者：陶懿洲刘超方贺男南京邮电大学电子与光学工程学院南京210023

扭曲双层石墨烯(TBG)由于具有莫特绝缘和非常规超导等新奇的电学特性,在纳米技术领域存在巨大的应用潜力.本文基于光学衍射物理方法,构建了一个适用于TBG的理论模型,并利用该理论模型研究了TBG的层间电导特性.研究结果较好地解释了TBG... 详细信息

扭曲双层石墨烯(TBG)由于具有莫特绝缘和非常规超导等新奇的电学特性,在纳米技术领域存在巨大的应用潜力.本文基于光学衍射物理方法,构建了一个适用于TBG的理论模型,并利用该理论模型研究了TBG的层间电导特性.研究结果较好地解释了TBG层间电导随扭转角变化的实验结果,并阐明了其物理机制.此外,本文还计算了电极参数、隧穿层厚度以及界面势强度等物理因素对层间电导特性的影响.计算结果表明:随着电极化学势的增大,层间电导关于扭转角的变化曲线近似整体向上平移;层间电导随着上层隧穿层厚度的增加而衰减并趋于稳定,而随着下层隧穿层厚度振荡;TBG两层扭转石墨烯的界面势强度越强,则层间电导随扭转角下降得越快.

关键词：低维物理层间电导光学衍射方法扭曲双层石墨烯

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Automatic facade recovery from single nighttime image

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Frontiers of Computer Science 2020年第1期14卷 95-104页

作者： yi zhou Qichuan GENG Zhong zhou Wei WU State Key Laboratory of Virtual Reality Technology and Systems Beihang UniversityBeijing 100083China

Nighttime images are difficult to process due to insufficient brightness,lots of noise,and lack of ***,they are always removed from time-lapsed image *** is interesting that nighttime images have a unique and wonderful building features that have robust and salient lighting cues from human *** variation depicts both the statistical and individual habitation,and it has an inherent man-made repetitive structure from architectural *** by this,we propose an automatic nighttime fa?ade recovery method that exploits the lattice structures of window ***,a simple but efficient classification method is employed to determine the salient bright regions,which may be lit *** we groupwindows into multiple lattice proposals with respect to fa?ades by patch matching,followed by greedily removing overlapping *** the horizon constraint,we solve the ambiguous proposals problem and obtain the correct ***,we complete the generated fa?ades by filling in the missing *** method is well suited for use in urban environments,and the results can be used as a good single-view compensation method for daytime *** method also acts as a semantic input to other learning-based 3D image reconstruction *** experiment demonstrates that our method works well in nighttime image datasets,and we obtain a high lattice detection rate of 82.1%of 82 challenging images with a low mean orientation error of 12.1±4.5 degrees.

关键词： facade recovery nighttime images lattice detection

Oxidation of emerging organic contaminants by in-situ H_(2)O_(2) fenton system

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Green Energy & Environment 2024年第3期9卷 417-434页

作者： Yuqin Ni Chuxiang zhou Mingyang Xing yi zhou State Environmental Protection Key Lab of Environmental Risk Assessment and Control on Chemical Processes School of Resources&Environmental EngineeringEast China University of Science and TechnologyShanghai200237China Key Laboratory for Advanced Materials and Institute of Fine Chemicals National Engineering Laboratory for Industrial Wastewater TreatmentSchool of Chemistry and Molecular EngineeringEast China University of Science and Technology130 Meilong RoadShanghai200237China Department of Applied Natural Sciences Technische Hochschule LubeckMonkhofer Weg 23923562 LubeckGermany

The existence and risk of emerging organic contaminants(EOCs)have been under consideration and paid much effort to degrade these *** system is one of the most widely used technologies to solve this *** original Fenton system relies on the hydroxyl radicals produced by Fe(Ⅱ)/H_(2)O_(2) to oxidize the organic ***,the application of the Fenton system is limited by its low iron cycling efficiency and the high risks of hydrogen peroxide transportation and *** introduction of external energy(including light and electricity etc.)can effectively promote the Fe(Ⅲ)/Fe(Ⅱ)cycle and the reduction of oxygen to produce hydrogen peroxide in *** review introduces three in-situ Fenton systems,which are electro-Fenton,Photo-Fenton,and chemical *** mechanism,influencing factors,and catalysts of these three in-situ Fenton systems in degrading EOCs are discussed *** review strengthens the understanding of Fenton and in-situ Fenton systems in degradation,offering further insight into the real application of the in-situ Fenton system in the removal of EOCs.

关键词： In-situ H_(2)O_(2)production Fenton Emerging organic contaminants Photocatalysis Electrocatalysis