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On fixity of arc-transitive graphs

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science China Mathematics 2021年第12期64卷 2603-2610页

作者： florian Lehner Primoz Potocnik Pablo spiga institute of Discrete Mathematics Graz University of TechnologyGraz 8010Austria Faculty of Mathematics and Physics University of LjubljanaLjubljana 1000Slovenia Dipartimento di Matematica Pura e Applicata University of Milano-BicoccaMilano 20126Italy

The relative xity of a permutation group is the maximum proportion of the points xed by a non-trivial element of the group,and the relative xity of a graph is the relative xity of its automorphism group,viewed as a permutation group on the vertex-set of the *** prove in this paper that the relative xity of connected 2-arc-transitive graphs of a xed valence tends to 0 as the number of vertices grows to in *** prove the same result for the class of arc-transitive graphs of a xed prime valence,and more generally,for any class of arc-transitive locally-L graphs,where L is a xed quasiprimitive graph-restrictive permutation group.

关键词： permutation group xity minimal degree graph automorphism group vertex-transitive arc-transitive xed points

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Recording spatially Resolved Plasma Parameters in Microwave-Driven Plasmas

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Plasma science and Technology 2013年第1期15卷 43-51页

作者： Gerhard FRANZ florian sCHAMBERGER igor KRsTEV stefan UMRATH Munich University of Applied sciences Munich D-80335

in an almost cubical reactor 90 1 in volume which is intended to deposit organic polymers by plasma-enhanced chemical vapor deposition （PECVD）, microwave power is coupled into the volume via a quartz window which extends to approximately 1/10 of the sidewall area. since the plasma is excited locally, plasma parameters like electron temperature and plasma density are expected to exhibit a spatial variation. The compilation of these plasma quantities has been accomplished with a bendable single Langmuir probe. To isolate the tungsten wire against its grounded housing tube, it was coated with polyparylene. After having compared this construction with our Langmuir probe, which has been now in use for more than a decade, we have taken data of more than half the volume of the reactor with argon and have found a definitive radial inhomogenity for all plasma parameters. To investigate whether this conduct can be determined applying optical emission spectroscopy, we improved our spectrometer which had been used for endpoint detection purposes and plasma diagnostics in chlorine-containing ambients where we could detect also a spatial dependence. This behavior is discussed in terms of Lieberman＇s global model.

关键词： high frequency and RF discharges optical measurements electric and mag-netic measurements

Prediction of sooting index of Fuel Compounds for spark-ignition Engine Applications Based on a Machine Learning Approach

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Journal of Thermal science 2023年第2期32卷 521-530页

作者： CHEN Zhuo VOM LEHN florian PiTsCH Heinz CAi Liming school of Automotive studies Tongji UniversityShanghai 201804China institute for Combustion Technology RWTH Aachen UniversityAachen 52056German

A joint consideration of potential combustion and emission performance in spark-ignition engines is essential for designing gasoline fuel replacements and additives,for which the knowledge of the fuels’characteristic properties forms the *** aim of this study is to predict sooting tendency of fuel molecules for spark-ignition engine applications in terms of their yield sooting indexes(Ysi).in conjunction with our previously developed database for gasoline compounds,which includes the physical and chemical properties,such as octane numbers,laminar burning velocity,and heat of vaporization,for more than 600 species,the identification of fuel replacements and additives can thus be performed jointly with respect to both their potential thermal efficiency benefits and emission formation characteristics in spark-ignition *** this purpose,a quantitative structure-property relationship(QsPR)model is developed to predict the Ysi of fuel species by using artificial neural network(ANN)techniques with 21 well-selected functional group descriptors as input *** model is trained and cross-validated with the Ysi database reported by Yale *** is then applied to estimate the Ysi values of fuels available in the database for gasoline compounds and to explore the sensitivity of fuel’s sooting tendency on molecular *** addition,the correlation of Ysi values with other properties available in the gasoline fuel database is examined to gain insights into the dependence of these ***,a selection of potential gasoline blending components is carried out exemplarily,by taking the fuels’potential benefits in thermal engine efficiency and their soot formation characteristics jointly into account in terms of efficiency merit function and Ysi,respectively.

关键词： yield sooting index gasoline replacements and additives quantitative structure-property relationship artificial neural network

Theme Park Metatexts:An Aesthetics of inclusion and Exclusion

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Journal of Foreign Languages and Cultures 2019年第1期3卷 1-10页

作者： florian Freitag Johannes Gutenberg University Mainz

This article uses the examples of guide maps,so-called autothemed rides,and apps to examine the aesthetics of theme park metatexts,that is,medial representations of theme parks or parts thereof that are produced by the parks themselves and that serve as a medial interface between the park landscape and its *** theme park metatexts have frequently been employed as sources in theme park research,but have only very rarely been figured as objects of research *** on Lukas’s description of theme parks’representational strategies as a“politics of inclusion/exclusion,”the essay argues that theme park metatexts stress certain aspects of the park while deemphasizing others,and thus have a major impact on the way visitors anticipate,experience,and remember the *** applies to more“traditional”forms of metatexts such as printed guide maps,which are handed out for free to theme park visitors,to“autothemed”rides,in which the theme park represents itself in the medium of the theme park ride,but especially to theme park apps,which not only further intensify the“politics of exclusion”of,for example,guide maps,but also involve the visitor in their selection processes.

关键词： theme parks Disney popular culture apps cartography

Composite integers n for Which φ(n)|n-1

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Acta Mathematica sinica,English series 2007年第10期23卷 1915-1918页

作者： William D.BANKs florian LUCA Department of Mathematics University of MissouriColumbiaMO 65211USA instituto de Matemáticas Universidad Nacional Autdnoma de MéxicoC.P.58089 MoreliaMichoacánMéxico

in this note, we show that the number of composite integers n ≤ x such that φ（n）｜n - 1 is at most O（x^1/2（loglog x）^1/2）, thus improving earlier results by Pomerance and by shan.

关键词： Euler function Lehmer conjecture

Tension-free Dirac strings and steered magnetic charges in 3D artificial spin ice

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npj Computational Materials 2021年第1期7卷 1127-1134页

作者： sabri Koraltan florian slanovc florian Bruckner Cristiano Nisoli Andrii V.Chumak Oleksandr V.Dobrovolskiy Claas Abert Dieter suess Physics of Functional Materials Faculty of PhysicsUniversity of ViennaViennaAustria Theoretical Division Los Alamos National LaboratoryLos AlamosNMUSA Nanomagnetics and Magnonics Faculty of PhysicsUniversity of ViennaViennaAustria Research Platform MMM Mathematics-Magnetism-Materials University of ViennaViennaAustria

3D nano-architectures presents a new paradigm in modern condensed matter physics with numerous applications in photonics,biomedicine,and *** are promising for the realization of 3D magnetic nano-networks for ultra-fast and low-energy data *** in these systems can lead to magnetic charges or magnetic monopoles,which can function as mobile,binary information ***,Dirac strings in 2D artificial spin ices bind magnetic charges,while 3D dipolar counterparts require cryogenic temperatures for their ***,we present a micromagnetic study of a highly frustrated 3D artificial spin ice harboring tension-free Dirac strings with unbound magnetic charges at room *** use micromagnetic simulations to demonstrate that the mobility threshold for magnetic charges is by 2 eV lower than their unbinding *** applying global magnetic fields,we steer magnetic charges in a given direction omitting unintended *** introduced system paves the way toward 3D magnetic networks for data transport and storage.

关键词： stability magnetic artificial

Effect of spin-orbit coupling on the high harmonics from the topological Dirac semimetal Na3Bi

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npj Computational Materials 2022年第1期8卷 1379-1387页

作者： Nicolas Tancogne-Dejean florian G.Eich Angel Rubio Max Planck institute for the structure and Dynamics of Matter and Center for Free-Electron Laser science Luruper Chaussee 14922761HamburgGermany European Theoretical spectroscopy Facility(ETsF) Donostia-San SebastianSpain HQs Quantum simulations GmbH Haid-und-Neu-Straße 7D-76131KarlsruheGermany Nano-Bio spectroscopy Group Universidad del País Vasco20018San SebastiánSpain Center for Computational Quantum Physics(CCQ) The Flatiron Institute162 Fifth AvenueNew YorkNY10010USA

in this work,we performed extensive first-principles simulations of high-harmonic generation in the topological Diract semimetal Na_(3)Bi using a first-principles time-dependent density functional theory framework,focusing on the effect of spin-orbit coupling(sOC)on the harmonic *** also derived an analytical model describing the microscopic mechanism of strong-field dynamics in presence of spin-orbit coupling,starting from a locally U(1)×sU(2)gauge-invariant *** results reveal that sOC:(i)affects the strong-field excitation of carriers to the conduction bands by modifying the bandstructure of Na_(3)Bi,(ii)makes each spin channel reacts differently to the driven laser by modifying the electron velocity(iii)changes the emission timing of the emitted ***,we show that the sOC affects the harmonic emission by directly coupling the charge current to the spin currents,paving the way to the high-harmonic spectroscopy of spin currents in solids.

关键词： coupling harmonic harmonics

The role of polysulfide-saturation in electrolytes for high power applications of real world Li-s pouch cells

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Nano Research 2023年第6期16卷 8313-8320页

作者： Tom Boenke sebastian Kirchhoff florian sReuter florian schmidt Christine Weller susanne Dörfler Kai schwedtmann Paul Härtel Thomas Abendroth Holger Althues Jan J.Weig stefan Kaskel Technische Universität Dresden Chair of Inorganic Chemistry IBergstr.6601069 DresdenGermany Fraunhofer institute for Material and Beam Technology(iWs) Winterbergstr.2801277 DresdenGermany Technische Universität Dresden Chair of Inorganic Molecular ChemistryMommsenstraße 401069 DresdenGermany

The lithium-sulfur(Li-s)technology is the most promising candidate for next-generation batteries due to its high theoretical specific energy and steady progress for applications requiring lightweight batteries such as aviation or heavy electric *** these applications,however,the rate capability of Li-s cells requires significant *** electrolyte formulations in Li-s batteries enable new pathways for cell development and adjustment of all ***,their rate capability at pouch cell level is often neither evaluated nor compared to state of the art(sOTA)LiTFsi/dimethoxyethane/dioxolane(LiTFsi:lithium-bis(trifluoromethylsulfonyl)imide)***,the combination of the sparingly polysulfide(Ps)solvating hexylmethylether/1,2-dimethoxyethane(HME/DME)electrolyte and highly conductive carbon nanotube Buckypaper(CNT-BP)with low porosity was evaluated in both coin and pouch cells and compared to dimethoxyethane/dioxolane reference *** advanced sulfur transfer melt infiltration was employed for cathode production with *** Li+ion coordination in the HME/DME electrolyte was investigated by nuclear magnetic resonance(NMR)and Raman ***,ionic conductivity and viscosity was investigated for the pristine electrolyte and a polysulfide-statured *** electrolytes,DME/DOL-1/1(DOL:1,3-dioxolane)and HME/DME-8/2,are then combined with CNT-BP and transferred to multi-layered pouch *** study reveals that the ionic conductivity of the electrolyte increases drastically over state of(dis)charge especially for DME/DOL electrolyte and lean electrolyte regime leading to a better rate capability for the sparingly polysulfide solvating *** evaluation in prototype cells is an important step towards bespoke adaption of Li-s batteries for practical applications.

关键词： lithium-sulfur pouch cell polysulfide solubility electrolyte characterization high power

Characteristics of developing scour-holes at a sand-embedded cylinder

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international Journal of sediment Research 2008年第3期23卷 258-266页

作者： Oscar LiNK florian PFLEGER Ulrich ZANKE Dept. of Civil Engineering University of Concepción Edmundo Larenas 270 Concepción Chile.Dr.-Ing. Assistant Prof. Doctoral Research Fellow Institute for Hydromechanics Technische Universitt München Arcisstrasse 21 80333 München Germany. institute for Hydraulic and Water Resources Engineering Darmstadt University of Technology Rundeturmstraβe 1 64283 Germany.Full Prof.

Characteristics of developing scour-holes at a sand-embedded 0.2 m diameter circular cylinder are presented. Non-intrusive, high-resolution topographic measurements of developing scour-holes were made with an experimental installation using a laser distance sensor (LDs) and precision step-motors. A clear-water experiment was conducted with bed shear stress equal to 95% of the critical bed shear stress for the initiation of sediment motion at the undisturbed plane sand bed with a d50 of 0.26 mm. During the running experiment of 21 hours duration, measurements were taken by the LDs in different azimuthal half-planes with θ = 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 and 180o in order to study the spatio-temporal variation of geometric properties in developing scour-holes. After 21 hours, the equilibrium condition was approached, with a scour rate less than d50 per hour. Measurement of maximum scour depth in different azimuthal half-planes at different points in time during the experiment show that scour started at the cylinder side and surrounded the cylinder after about 20% of experiment time. slopes of developing scour-holes presented three regions with different inclinations, which were attributed to vortex action. Both maximum scour depth and maximum scour radius at different azimuthal half-planes are well correlated with the maximum scour depth at plane with θ = 0o. When providing maximum scour depth at the cylinder front, the presented correlations are useful for simple calculation of scour-hole topography. This work provides an experimental database for advanced numerical simulation for loose sediment hydraulics.

关键词： scour Bridges Piers sediment transport Loose sediment hydraulics