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Trigonometric multiplicative chaos and applications to random distributions

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Science China Mathematics 2023年第1期66卷 3-36页

作者： Aihua Fan Yves meyer School of Mathematics and Statistics Central China Normal UniversityWuhan 430079China LAMFA CNRSUMR7352University of PicardieAmiens 80039France CMLA ENS-CachanCNRSUniversityof Paris-SaclayParis 91190France

The random trigonometric series∑∞n=1ρn cos(nt+ωn)on the circle T are studied under the conditions∑|ρn|^(2)=∞andρn→0,where{ωn}are independent and uniformly distributed random variables on *** are almost surely not Fourier-Stieltjes series but determine *** leads us to develop the theory of trigonometric multiplicative chaos,which produces a class of random *** kernel and the image of chaotic operators are fully studied and the dimensions of chaotic measures are exactly *** behavior of the partial sums of the above series is proved to be *** theory holds on the torus Tdof dimension d≥1.

关键词： multiplicative chaos random Fourier series Hausdorff dimension Riesz potential

Impact of insulator layer thickness on the performance of metal-MgO-ZnO tunneling diodes

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Nano Research 2016年第5期9卷 1290-1299页

作者： Yousong Gu max A. Migliorato Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Municipal Key Laboratory of New Energy Materials and Technologies Beijing 100083 China School of Electrical and Electronic Engineering University of Manchester Manchester M13 9PL UK

The performance of metal-insulator-semiconductor （MIS） type tunneling diodes based on ZnO nanostructures is investigated through modeling. The framework used in this work is the Schr6dinger equation with an effective-mass approximation. The working mechanism of the MIS type tunneling diode is investigated by examining the electron density, electric field, electrostatic potential, and conduction band edge of the device. We show that a valley in the electrostatic potential is formed at the ZnO/MgO interface, which induces an energy barrier at the ZnO side of this interface. Therefore, electrons need to overcome two barriers： the high and narrow MgO barrier, and the barrier from the depletion region induced at the ZnO side of the ZnO/MgO interface. As the MgO layer becomes thicker, the valley in electrostatic potential becomes deeper. At the same time, the barrier induced at the ZnO/MgO interface becomes higher and wider. This leads to a fast decrease in the current passing through the MIS diode. We optimize the thickness of the MgO insulating layer, sandwiched between a ZnO film （in this work we use a single ZnO nanowire） and a metal contact, to achieve maximum performance of the diode, in terms of rectification ratio. An optimal MgO layer thickness of 1.5 nm is found to yield the highest rectification ratio, of approximately 169 times that of a conventional metal-semiconductor-metal Schottky diode. These simulated results can be useful in the design and optimization of ZnO nanodevices, such as light emitting diodes and UV photodetectors.

关键词： metal-insulator-semicon ductor (MIS) diode ZnO nanodevices MgO layer tunneling mechanism

Pathology-induced NG2 proteoglycan expression in microglia

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Neural Regeneration Research 2023年第4期18卷 801-802页

作者： Erika meyer Anja Scheller Molecular Physiology Center for Integrative Physiology and Molecular MedicineUniversity of SaarlandHomburgGermany(Meyer EScheller A)Laboratory of Brain Ischemia and NeuroprotectionDepartment of Pharmacology and TherapeuticsState University of MaringáMaringáBrazil

Oligodendrocyte precursor cells(OPCs)and microglia are two very fascinating cell types with a multitude of important but different *** a first glance,they appear not to share many cellular properties,nor are directly related to one another or derived from a common *** all differences,emerging data show that both cell types express the protein nerve/glial antigen 2(NG2)after pathological insults(Figure 1).For years,it remained controversial whether microglia really could express NG2 upon injury,with contradictory results reported among different disease *** this question,we could recently show by using triple transgenic knock-in mice and either an acute injury model(stab wound injury)or the middle cerebral artery occlusion combined with immunohistochemistry that a subset of microglia activates the cspg4 gene in a disease dependent manner leading to a bonafide microglia-specific NG2 protein expression besides OPCs and *** data show that the cspg4 gene not only gets transcribed in microglia based on reporter expression after recombination,but also the protein itself is expressed(Huang et al.,2020).

关键词： NG2 wound Figure

Bridging Methods for Atomistic-to-Continuum Coupling and Their Implementation

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Communications in Computational Physics 2010年第4期7卷 831-876页

作者： Pablo Seleson max Gunzburger Department of Scientific Computing Florida State UniversityTallahasseeFL 32306-4120USA

Several issues connected with bridging methods for atomistic-to-continuum(AtC)coupling are *** coupling approaches using various energy blending models are studied as well as the influence that model parameters,blending functions,and grids have on simulation *** use the Lagrange multiplier method for enforcing constraints on the atomistic and continuum displacements in the bridge *** also show that continuum models are not appropriate for dealing with problems with singular loads,whereas AtC bridging methods yield correct results,thus justifying the need for a multiscale *** investigate models that involve multiple-neighbor interactions in the atomistic region,particularly focusing on a comparison of several approaches for dealing with Dirichlet boundary conditions.

关键词： Multiscale modeling atomistic-to-continuum coupling boundary treatment

Reconstruction of paleocoastlines for the northwestern South China Sea since the Last Glacial maximum

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Science China Earth Sciences 2009年第8期52卷 1127-1136页

作者： HARFF Jan meyer Michael Leibniz Institute for Baltic Sea Research Warnemünde

The range of relative sea level rise in the northwestern South China Sea since the Last Glacial maximum was over 100 m. As a result, lowland regions including the Northeast Vietnam coast, Beibu Gulf, and South China coast experienced an evolution from land to sea. Based on the principle of reconstructing paleogeography and using recent digital elevation model, relative sea level curves, and sediment accumulation data, this paper presents a series of paleogeographic scenarios back to 20 cal. ka BP for the northwestern South China Sea. The scenarios demonstrate the entire process of coastline changes for the area of interest. During the late glacial period from 20 to 15 cal. ka BP, coastline slowly retreated, causing a land loss of only 1×104 km2, and thus the land-sea distribution remained nearly unchanged. Later in 15-10 cal. ka BP coastline rapidly retreated and area of land loss was up to 24×104 km2, causing lowlands around Northeast Vietnam and South China soon to be underwater. Coastline retreat continued quite rapidly during the early Holocene. From 10 to 6 cal. ka BP land area had decreased by 9×104 km2, and during that process the Qiongzhou Strait completely opened up. Since the mid Holocene, main controls on coastline change are from vertical crustal movements and sedimentation. Transgression was surpassed by regression, resulting in a land accretion of about 10×104 km2.

关键词： relative sea level change paleocoastline reconstruction Last Glacial maximum northwestern South China Sea

Nanomaterials for Clean Air, Energy and Water

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Progress in Natural Science:Materials International 2018年第2期28卷 97-98页

作者： G.Q.(max) Lu University of Surrey

In the last decade,environmental pressures due to air and water pollution and the drive for clean energy supply are rising,which have led to the tremendous interest and investment in sustainable materials *** has been at the forefront of research and development of clean technologies for air,water and energy not surprisingly because of the strong need for such technologies to balance development and

关键词： Energy and Water Nanomaterials for Clean Air

Numerical micro-texture optimization for lubricated contacts-A critical discussion

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Friction 2022年第11期10卷 1772-1809页

作者： max MARIAN Andreas ALMQVIST Andreas ROSENKRANZ Michel FILLON Department of Mechanical and Metallurgical Engineering Pontificia Universidad Católica de ChileSantiago 690411Chile Division of Machine Elements LuleåUniversity of TechnologyLuleåSE-97187Sweden Department of Chemical Engineering Biotechnology and MaterialsFCFMUniversity of ChileSantiago 8370456Chile Institut Pprime CNRSUniversity of PoitiersPoitiers Cedex TSA 4112386073France

Despite numerous experimental and theoretical studies reported in the literature,surface micro-texturing to control friction and wear in lubricated tribo-contacts is still in the trial-and-error *** tribological behaviour and advantageous micro-texture geometries and arrangements largely depend on the contact type and the operating *** scale implementation is hampered by the complexity of numerical *** substantiates the urgent need to numerically design and optimize micro-textures for specific *** these aspects have not been covered by other review articles yet,we aim at summarizing the existing state-of–the art regarding optimization strategies for micro-textures applied in hydrodynamically and elastohydrodynamically lubricated *** analysis demonstrates the great potential of optimization strategies to further tailor micro-textures with the overall aim to reduce friction and wear,thus contributing toward an improved energy efficiency and sustainability.

关键词： micro-texturing hydrodynamics elastohydrodynamics tribo-simulation optimization

Superlubricity on the nanometer scale

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Friction 2014年第2期2卷 106-113页

作者： Ernst meyer Enrico GNECCO Department of Physics University of BaselKlingelbergstr.824056 BaselSwitzerland IMDEA Nanociencia Campus Universitario de CantoblancoCalle Faraday 928049 MadridSpain

The transition from atomic stick-slip to continuous sliding has been observed in a number of *** extended contacts are moved in different directions,so-called structural lubricity is observed when the two surface lattices are ***,a“superlubric”state of motion can be achieved if the normal force is reduced below a certain threshold,the temperature is increased,or the contact is actuated *** processes have been partially demonstrated using atomic force microscopy,and they can be theoretically understood by proper modifications of the Prandtl−Tomlinson model.

关键词： structural lubricity dynamic superlubricity atomic force microscopy friction force microscopy themolubricity Prandtl−Tomlinson model

Why did life develop on the surface of the Earth in the Cambrian？

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Geoscience Frontiers 2016年第6期7卷 865-873页

作者： Carlo Doglioni Johannes Pignatti max Coleman Department of Earth Sciences Sapienza University 00185 Rome Italy NASA Jet Propulsion Laboratory California Institute of Technology Pasadena CA 91109 USA NASA Astrobiology Institute USA

Life was limited for most of Earth＇s history, remaining at a primitive stage and mostly marine until about 0.55 Ga. In the Paleozoic, life eventually exploded and colonized the continental realm. Why had there been such a long period of delayed evolution of life？ Early life was dominated by Archaea and Bacteria, which can survive ionizing radiation better than other organisms. The magnetic field preserves the atmosphere, which is the main shield of UV radiation. We explore the hypothesis that the Cambrian explosion of life could have been enabled by the increase of the magnetic field dipole intensity due to the solidification of the inner core, caused by the cooling of the Earth, and the concomitant decrease with time of the high-energy solar flux since the birth of the solar system. Therefore, the two phenomena could be responsible for the growth and thickening of the atmosphere and the development of land surface life.

关键词： Origin of lifeInner core solidificationSolar ionizing radiations