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Characterization of image spaces of Riemann-Liouville fractional integral operators on Sobolev spaces W^(m,p)(Ω)

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Science China Mathematics 2021年第12期64卷 2611-2636页

作者： Lijing Zhao Weihua deng Jan S.Hesthaven School of Mathematics and Statistics Northwestern Polytechnical UniversityXi'an 710129China School of Mathematics and Statistics Gansu Key Laboratory of Applied Mathematics and Complex SystemsLanzhou UniversityLanzhou 730000China epfl-SB-MATHICSE-MCSS Ecole Polytechnique Federale de LausanneLausanne CH-1015Switzerland

fractional operators are widely used in mathematical models describing abnormal and nonlocal *** there are extensive numerical methods for solving the corresponding model problems,theoretical analysis such as the regularity result,or the relationship between the left-side and right-side fractional operators is seldom *** of considering the fractional derivative spaces,this paper starts from discussing the image spaces of Riemann-Liouville fractional integrals of L_(p)(Ω) functions,since the fractional derivative operators that are often used are all *** the high regularity situation-the image spaces of Riemann-Liouville fractional integral operators on the W^(m,p)(Ω) space is *** characterizations of the defined spaces,as well as those of the intersection of the left-side and right-side spaces are *** behavior of the functions in the defined spaces at both the nearby boundary point/points and the points in the domain is demonstrated in a clear ***,tempered fractional operators are shown to be reciprocal to the corresponding Riemann-Liouville fractional operators,which is expected to contribute some theoretical support for relevant numerical ***,we also provide some instructions on how to take advantage of the introduced spaces when numerically solving fractional equations.

关键词： image space Riemann-Liouville integral regularity property approximation

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Comparison Between Reconstructions of Global Anthropogenic Land Cover Change over Past Two Millennia

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Chinese Geographical Science 2013年第2期23卷 131-146页

作者： YAN Mi WANG Zhiyuan Jed Oliver KAPLAN LIU Jian MIN Shen WANG Sumin Key Laboratory of Virtual Geographic Environment of Ministry of Education School of Geography ScienceNanjing Normal University State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences University of Chinese Academy of Science Environmental Engineering Institute Ecole Polytechnique Fédérale de Lausanne

Three global datasets, the History database of the Global Environment （HYde）, Kaplan and Krurnhardt （KK） and Pongratz of reconstructed anthropogenic land cover change （ALCC） were introduced and compared in this paper. The HYde dataset was recon- structed by Goldewijk and his colleagues at the National institute of Public ttealth and the Environment in Netherland, covering the past 12 000 years. The KK dataset was reconstructed by Kaplan and his colleagues, the Soil-Vegetation-Atmosphere Research Group at the Institute of Environmental Engineering in Switzerland, covering the past 8000 years. The Pongratz dataset was reconstructed by Pon- gratz and her colleagues at the Max Planck Institute for Meteorology in Germany, coveting Ad 800-1992. The results show that the reconstructed datasets are quite different from each other due to the different methods used. The three datasets all allocated the historical ALCC according to human population density. The main reason causing the differences among the three datasets lies on the different relationships between population density and land use used in each reconstructed dataset. The KK dataset is better than the other two datasets for two important reasons. first, it used the nonlinear relationship between population density and land use, while the other two used the linear relationship. Second, Kaplan and his colleagues adopted the technological development and intensification parameters and considered the wood harvesting and the long-term fallow area resulted from shifting cultivation, which were neglected in the recon- structions of the other two datasets. Therefore, the KK dataset is more suitable as one of the anthropogenic forcing fields for climate simulation over the past two millennia that is recently concerned by two projects, the National Basic Research Program and the Strategic and Special frontier Project of Science and Technology of the Chinese Academy of Sciences.

关键词： anthropogenic land cover change (ALCC) spatial pattern vegetation type global dataset last two millennia

Automated phenotyping of Caenorhabditis elegans embryos with a high-throughput-screening microfluidic platform

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Microsystems & Nanoengineering 2020年第1期6卷 1103-1116页

作者： Huseyin Baris Atakan Tunc Alkanat Matteo Cornaglia Raphael Trouillon Martin A.M.Gijs Laboratory of Microsystems Ecole Polytechnique Federale de Lausanne1015 LausanneSwitzerland department of Electrical Engineering Eindhoven University of Technology5600MB EindhovenThe Netherlands

The nematode Caenorhabditis elegans has been extensively used as a model multicellular organism to study the influence of osmotic stress conditions and the toxicity of chemical compounds on developmental and motility-associated ***,the several-day culture of nematodes needed for such studies has caused researchers to explore *** particular,*** embryos,due to their shorter developmental time and immobile nature,could be exploited for this purpose,although usually their harvesting and handling is ***,we present a multiplexed,high-throughput and automated embryo phenotyping microfluidic approach to observe *** embryogenesis after the application of different chemical *** performing experiments with up to 800 embryos per chip and up to 12h of time-lapsed imaging per embryo,the individual phenotypic developmental data were collected and analyzed through machine learning and image processing *** proof-of-concept platform indicates developmental lag and the induction of mitochondrial stress in embryos exposed to high doses(200mM)of glucose and NaCl,while small doses of sucrose and glucose were shown to accelerate ***,our new technique has potential for use in large-scale developmental biology studies and opens new avenues for very rapid high-throughput and high-content screening using *** embryos.

关键词： doses fluid harvesting

Experimental evidence of Bloch surface waves on photonic crystals with thin-film LiNbO_3 as a top layer

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Photonics Research 2017年第6期5卷 168-172页

作者： TATIANA KOVALEVICH dJAffAR BELHARET LAURENT ROBERT MYUN-SIK KIM HANS PETER HERZIG THIERRY GROSJEAN MARIA-PILAR BERNAL département d'Optique P.M.duffieux Institut FEMTO-ST UMR 6174 CNRS Université Bourgogne Franche-Comté Optics & Photonics Technology Laboratory Ecole Polytechnique Fédérale de Lausanne (EPFL)

Strong nonlinear, electro-optical, and thermo-optical properties of lithium niobate(LN) have gained much attention. However, the implementation of LiNbO_3 in real devices is not a trivial task due to difficulties in manufacturing and handling thin-film LN. In this study, we investigate an optical device where the Bloch surface wave(BSW) propagates on the thin-film LN to unlock its properties. first, access to the LN film from air(or open space) is important to exploit its properties. Second, for sustaining the BSW, one-dimensional photonic crystal(1dPhC) is necessary to be fabricated under the thin-film LN. We consider two material platforms to realize such a device: bulk LN and commercial thin-film LN. Clear reflectance dips observed in far-field measurements demonstrate the propagation of BSWs on top of the LN surface of the designed 1dPhCs.

关键词： LN Li Experimental evidence of Bloch surface waves on photonic crystals with thin-film LiNbO3 as a top layer

Stacking transition in rhombohedral graphite

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frontiers of physics 2019年第1期14卷 67-73页

作者： Tataiana Latychevskaia Seok-Kyun Son Yaping Yang dale Chancellor Michael Brown Servet Ozdemir Ivan Madan Gabriele Berruto fabrizio Carbone Artem Mishchenko Kostya S. Novoselov Institute of Physics Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES)école Polytechnique Fédérale de Lausanne (EPFL) CH-1015 Lausanne Switzerland National Graphene Institute University of Manchester Oxford Road Manchester M13 9PL UK School of Physics and Astronomy University of Manchester Oxford Road Manchester M13 9PL UK

few-layer graphene (fLG) has recently been intensively investigated for its variable electronic properties, which are defined by a local atomic arrangement. While the most natural arrangement of layers in fLG is ABA (Bernal) stacking, a metastable ABC (rhombohedral) stacking, characterized by a relatively high-energy barrier, can also occur. When both types of stacking occur in one fLG device, the arrangement results in an in-plane heterostructure with a domain wall (dW). In this paper, we present two approaches to demonstrate that the ABC stacking in fLG can be controllably and locally turned into the ABA stacking. In the first approach, we introduced Joule heating, and the transition was characterized by 2d peak Raman spectra at a submicron spatial resolution. The transition was initiated in a small region, and then the dW was controllably shifted until the entire device became ABA stacked. In the second approach, the transition was achieved by illuminating the ABC region with a train of 790-nm-wavelength laser pulses, and the transition was visualized by transmission electron microscopy in both diffraction and dark-field imaging modes. further, using this approach, the dW was visualized at a nanoscale spatial resolution in the dark-field imaging mode.

关键词： graphene graphite van der Waals heterostructures domain wall Raman spectroscopy transmission electron microscopy electron diffraction structural transition

A Technical Review of Hydro-Project development in China

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Engineering 2016年第3期2卷 302-312页

作者： Rafael duarte António Pinheiro Anton J. Schleiss Laboratory of Hydraulic Constructions (LCH) école polytechnique fédérale de Lausanne (EPFL) Civil Engineering Research and Innovation for Sustainability (CERIS) Instituto Superior Técnico Universidade de Lisboa

This paper summarizes the development of hydro-projects in China,blended with an international *** expounds major technical progress toward ensuring the safe construction of high dams and river harnessing,and covers the theorization of uneven non-equilibrium sediment transport,inter-basin water diversion,giant hydro-generator units,pumped storage power stations,underground caverns,ecological protection,and so on.

关键词： damRiver harnessingWater diversionPumped storage power stationUnderground cavernEcological protection

Rate-distortion optimized frame dropping and scheduling for multi-user conversational and streaming video

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第5期7卷 864-872页

作者： CHAKARESKI Jacob STEINBACH Eckehard ecole polytechnique federale de lausanne Signal Processing Institute LTS4 Lausanne CH-1015 Switzerland Media Technology Group Institute of Communication Networks Munich University of Technology Munich D-80333 Germany

We propose a Rate-distortion (Rd) optimized strategy for frame-dropping and scheduling of multi-user conversa- tional and streaming videos. We consider a scenario where conversational and streaming videos share the forwarding resources at a network node. Two buffers are setup on the node to temporarily store the packets for these two types of video applications. for streaming video, a big buffer is used as the associated delay constraint of the application is moderate and a very small buffer is used for conversational video to ensure that the forwarding delay of every packet is limited. A scheduler is located behind these two buffers that dynamically assigns transmission slots on the outgoing link to the two buffers. Rate-distortion side information is used to perform Rd-optimized frame dropping in case of node overload. Sharing the data rate on the outgoing link between the con- versational and the streaming videos is done either based on the fullness of the two associated buffers or on the mean incoming rates of the respective videos. Simulation results showed that our proposed Rd-optimized frame dropping and scheduling ap- proach provides significant improvements in performance over the popular priority-based random dropping (PRd) technique.

关键词： Rate-distortion optimization, Video frame dropping, Conversational video, Streaming video, distortion matrix, Hinttracks, Scheduling, Resource assignment

Two-dimensional MXenes for lithium-sulfur batteries

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InfoMat 2020年第4期2卷 613-638页

作者： Chuanfang(John)Zhang Linfan Cui Sina Abdolhosseinzadeh Jakob Heier Laboratory for functional Polymers EmpaSwiss Federal Laboratories for Materials Science and TechnologyDubendorfSwitzerland department of Electronics and Nanoengineering Aalto UniversityAaltoFinland Institute of Materials Science and Engineering Ecole Polytechnique Federale de Lausanne(EPFL)LausanneSwitzerland

Rechargeable lithium-sulfur(Li-S)batteries have attracted significant research attention due to their high capacity and energy ***,their commercial applications are still hindered by challenges such as the shuttle effect of soluble lithium sulfide species,the insulating nature of sulfur,and the fast capacity decay of the *** efforts are devoted to address these problems through questing more conductive hosts with abundant polysulfide chemisorption sites,as well as modifying the separators to physically/chemically retard the polysulfides *** dimensional transition metal carbides,carbonitrides and nitrides,so-called MXenes,are ideal for confining the polysulfides shuttling effects due to their high conductivity,layered structure as well as rich surface *** such,MXenes have thus been widely studied in Li-S batteries,focusing on the conductive sulfur hosts,polysulfides interfaces,and ***,in this review,we summarize the significant progresses regarding the design of multifunctional MXene-based Li-S batteries and discuss the solutions for improving electrochemical performances in *** addition,challenges and perspectives of MXenes for Li-S batteries are also outlined.

关键词： flexible electronics Li-S battery MXene polysulfides shuttling two dimensional materials

Effects of the discharge Parameters on the Efficiency and Stability of Ambient Metastable-Induced desorption Ionization

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Plasma Science and Technology 2015年第12期17卷 1048-1052页

作者：张晓天陈池来刘友江王泓伟张乐华孔德义 Mario CHAVARRIA State Key Laboratory of Transducer Technology Hefei Institute of Intelligent MachinesCAS College of Electronic Science and Applied Physics University of Technology department of Automation University of Science and Technology of China Microsystems Laboratory Ecole Polytechnique Federale de Lausanne(EPFL)

Ionization efficiency is an important factor for ion sources in mass spectrometry and ion mobility *** helium as the discharge gas,acetone as the sample,and high-field asymmetric ion mobility spectrometry（fAIMS） as the ion detection method,this work investigates in detail the effects of discharge parameters on the efficiency of ambient metastableinduced desorption ionization（AMdI） at atmospheric *** results indicate that the discharge power and gas flow rate are both significantly correlated with the ionization ***,an increase in the applied discharge power leads to a rapid increase in the ionization efficiency,which gradually reaches equilibrium due to ion ***,when the discharge voltage is fixed at 2.1 kV,a maximum efficiency can be achieved at the flow rate of 9.0 m/*** study provides a foundation for the design and application of AMdI for on-line detection with mass spectrometry and ion mobility spectrometry.

关键词： ambient helium ionization asymmetric desorption metastable saturation acetone reaches unexpected