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Deformations at Earth’s dayside magnetopause during quasi-radial IMF conditions:Global kinetic simulations and Soft X-ray Imaging

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Earth and Planetary Physics 2024年第1期8卷 59-69页

作者： ZhongWei Yang RiKu Jarvinen XiaoCheng Guo TianRan Sun Dimitra Koutroumpa George K.Parks Can Huang BinBin Tang QuanMing Lu Chi Wang State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Finnish Meteorological Institute FI-00101 HelsinkiFinland LATMOS/IPSL CNRSUVSQ UniversitéParis-SaclaySorbonne UniversitéGuyancourt78280France Space Sciences Laboratory University of CaliforniaBerkeleyCalifornia 94720USA CAS Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029 China Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China

The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)is a joint mission of the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS).Primary goals are investigating the dynamic response of the Earth's magnetosphere to the solar wind(SW)impact via simultaneous in situ magnetosheath plasma and magnetic field measurements,X-Ray images of the magnetosheath and magnetic cusps,and UV images of global auroral *** deformations associated with magnetosheath high speed jets(HSJs)under a quasi-parallel interplanetary magnetic field condition are studied using a threedimensional(3-D)global hybrid *** X-ray intensity calculated based on both physical quantities of solar wind proton and oxygen ions is *** obtain key findings concerning deformations at the magnetopause:(1)Magnetopause deformations are highly coherent with the magnetosheath HSJs generated at the quasi-parallel region of the bow shock,(2)X-ray intensities estimated using solar wind h+and self-consistentO7+ions are consistent with each other,(3)Visual spacecraft are employed to check the discrimination ability for capturing magnetopause deformations on Lunar and polar orbits,*** SMILE spacecraft on the polar orbit could be expected to provide opportunities for capturing the global geometry of the magnetopause in the equatorial plane.A striking point is that SMILE has the potential to capture small-scale magnetopause deformations and magnetosheath transients,such as HSJs,at medium altitudes on its *** results also demonstrate that a lunar based imager(e.g.,Lunar Environment heliospheric X-ray Imager,LEXI)is expected to observe a localized brightening of the magnetosheath during HSJ events in the meridian *** preliminary results might contribute to the pre-studies for the SMILE and LEXI missions by providing qualitative and quantitative soft X-ray estimates of dayside kinetic processes.

关键词： collisionless shock SMILE mission foreshock

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Two-photon emission from a superlattice-based superconducting light-emitting structure

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Light(Science & Applications) 2024年第7期13卷 1331-1340页

作者： Shlomi Bouscher Dmitry Panna Ronen Jacovi Fauzia Jabeen Christian Schneider Sven Höfling Alex Hayat Department of Electrical Engineering TechnionHaifa 32000Israel. Technische Physik Universität WürzburgAm HublandD-97074 WürzburgGermany. Institute of Physics Carl von Ossietzky Universität OldenburgD-26111 OldenburgGermany

Superconductor-semiconductor hybrid devices can bridge the gap between solid-state-based and photonics-based quantum systems,enabling new hybrid computing schemes,offering increased scalability and *** example for a hybrid device is the superconducting light-emitting diode(SLED).SLEDs have been theoretically shown to emit polarization-entangled photon pairs by utilizing radiative recombination of Cooper ***,the twophoton nature of the emission has not been shown experimentally *** demonstrate two-photon emission in a GaAs/AlGaAs *** electroluminescence spectra reveal unique two-photon superconducting features below the critical temperature(Tc),while temperature-dependent photon-pair correlation experiments(g(2)(τ,T))demonstrate temperature-dependent time coincidences below Tc between photons emitted from the *** results pave the way for compact and efficient superconducting quantum light sources and open new directions in light-matter interaction studies.

关键词： photon quantum utilizing

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United under stress:High-speed transport network emerging at bacterial living edge

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Fundamental Research 2024年第3期4卷 563-569页

作者： Xiaodong Wen Jingjing Feng Yuqian Sang Feng Ge Hugues Chaté Yan He Department of Chemistry Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyTshinghua UniversityBeijing 100084China Service de Physique de l'Etat Condensé CEACNRSUniversitéParis-SaclayCEA-SaclayGif-sur-Yvette 91191France Beijing Computational Science Research Center Beijing 100094China

Individuals tend to move freely when there is enough room but would act collectively for their survival under external *** the case of living cells,for instance,when a drop of low-density flagellated bacterial solution is transferred onto the agar surface,the initially disordered movement of individual bacteria would be replaced with coordinated cell swarming after a lag phase of a few ***,we study how such cooperation is established while overcoming the disorder at the onset of the lag phase with single nanoparticle *** the spreading of the droplet,the bacteria in the solution cluster and align near the almost immobilized contact line confining the drop,forming a narrow ring of *** individual cells move in and out of the ring continuously,certain flow patterns emerge in the inter-bacterial *** reveal high-speed long-distance unidirectional flows with definite chirality along the outside of the ring,along the inside of the ring and across the *** speculate that these flows enable the fast and efficient transport,facilitating the communication and unification of the bacterial community.

关键词： Bacterial droplet Environmental stress Single particle tracking Biological edge Flow transport network

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Investigating the inflow into a granular bed using a locally resolved method

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Particuology 2024年第2期85卷 89-101页

作者： Maximilian Brommer Maik Scharnowski Enric Illana Mahiques Siegmar Wirtz Viktor Scherer Ruhr university Bochum Institute of Energy Plant TechnologyUniversitätsstraβe 15044780BochumGermany

Discrete Element Method-Computational Fluid Dynamics(DEM/CFD)simulations of industrial-scale granular systems employ spatial averaging(porous media approach)for the fluid-particle interaction in the whole domain,which can lead to poor accuracy,for instance at flow inlets,as local particle bulk morphology is not *** paper presents an approach where the interstitial flow in crucial areas with large gradients can be resolved locally in an otherwise unresolved domain,so that a mixed resolved-unresolved method is *** a generic example to show the feasibility and performance of the new approach,the inflow of ambient air into a flat-bottom hopper through a narrow orifice is *** an experimental setup,the vertical profile of the pressure decay through the inlet and across the packing is chosen for com-parison with respective *** obtained with the conventional porous media method and the locally resolved approach are compared to these experiments for varying volume flow rates and for two different particle *** of different size as well as dodecahedrons are *** is found that although averaging methods already provide good approximations,the locally resolved method can improve the result especially when conventional drag laws are not applicable due to wall effects or if large velocity gradients exist.

关键词： DEM/CFD Packed bed Pressure drop

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2023: Weather and Climate Extremes Hitting the Globe with Emerging Features

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Advances in Atmospheric Sciences 2024年第6期41卷 1001-1016页

作者： Wenxia ZHANG Robin CLARK Tianjun ZHOU Laurent LI Chao LI Juan RIVERA Lixia ZHANG Kexin GUI Tingyu ZHANG Lan LI Rongyun PAN Yongjun CHEN Shijie TANG Xin HUANG Shuai HU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Met Office Hadley Centre Exeter EX13PBUK university of Chinese Academy of Sciences Beijing 100049China Laboratoire de Météorologie Dynamique CNRSSorbonne UniversitéEcole Normale SupérieureEcole PolytechniqueParis 75230France Max Planck Institute for Meteorology Hamburg 20146Germany Instituto Argentino de Nivología Glaciología Y Ciencias Ambientales(IANIGLA)CCT CONICETMendoza CP 5500Argentina Shanghai Typhoon Institute China Meteorological AdministrationShanghai 200030China Asia-Pacific Typhoon Collaborative Research Center Shanghai 201306China

Globally,2023 was the warmest observed year on record since at least 1850 and,according to proxy evidence,possibly of the past 100000 *** in recent years,the record warmth has again been accompanied with yet more extreme weather and climate events throughout the ***,we provide an overview of those of 2023,with details and key background causes to help build upon our understanding of the roles of internal climate variability and anthropogenic climate *** also highlight emerging features associated with some of these extreme *** extremes are occurring earlier in the year,and increasingly simultaneously in differing parts of the world(e.g.,the concurrent hot extremes in the Northern Hemisphere in July 2023).Intense cyclones are exacerbating precipitation extremes(e.g.,the North China flooding in July and the Libya flooding in September).Droughts in some regions(e.g.,California and the Horn of Africa)have transitioned into flood *** extremes also show increasing interactions with ecosystems via wildfires(e.g.,those in Hawaii in August and in Canada from spring to autumn 2023)and sandstorms(e.g.,those in Mongolia in April 2023).Finally,we also consider the challenges to research that these emerging characteristics present for the strategy and practice of adaptation.

关键词： weather and climate extremes temperature extremes extreme precipitation drought wildfires

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Minimal Legendrian surfaces in the tangent sphere bundle of R3

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Science China Mathematics 2024年第11期67卷 2607-2628页

作者： Mingyan Li Guofang Wang School of Mathematical Sciences Ocean University of China Mathematisches Institut Albert-Ludwigs-Universit?t Freiburg

In this paper,we study minimal Legendrian surfaces Σ immersed in the tangent sphere bundle *** classify(1) totally geodesic Legendrian surfaces,(2) closed minimal Legendrian surfaces of genus smaller than or equal to 1 and complete minimal Legendrian surfaces with the non-negative Gauss curvature,and(3) complete stable minimal Legendrian surfaces.

关键词： 53C24 53C42 classification Legendrian surface stable minimal surface tangent sphere bundle

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Structural insight into palladium-nickel clusters over mordenite zeolite for carbene-insertion reaction

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 89-99页

作者： Guangchao Li Ping-Luen Baron Ho Bryan Kit Yue Ng Tai-Sing Wu Pawel Rymarz Shik Chi Edman Tsang Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityHong Kong 999077China Department of Chemistry University of OxfordOxford OX13QRUK Synchrotron Radiation Research Center Hsinchu 30076China

The advancement of heterogeneous catalysts incorporating metal clusters in the nanometric size range has garnered significant attention due to their extraordinary catalytic activity and *** detailed characterization and understanding of the atomic structure of these metal clusters within catalysts is crucial for elucidating the underlying reaction *** the present study,a distinctive three-atom PdNi cluster,characterized by two Pd atoms at terminal positions and a central Ni atom,was synthesized over mordenite *** presence of atomic PdNi clusters within the eight-membered ring side pocket area was confirmed by multiple advanced analytical techniques,including magic-angle spinning nuclear magnetic resonance spectroscopy,synchrotron X-ray powder diffraction,extended X-ray absorption fine structure spectroscopy,and high-angle annular dark-field scanning transmission electron *** catalytic activity of the confined active species was examined by the carbene-mediated reactions of ethyl-2-diazoacetate to ethyl-2-methoxyacetate as a model *** to the Pd-mordenite and Ni-mordenite,the PdNi-mordenite catalyst incorporates a PdNi cluster,which demonstrates a superior performance,achieving 100%conversion and high selectivity under the same reaction *** study elucidates the potential of constructing bimetallic clusters in zeolites,providing valuable insights for developing new heterogeneous catalysts applicable to a wide range of catalytic processes.

关键词： zeolite metal cluster synchrotron X-ray diffraction carbene-mediated reaction

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Controlling the reaction network of Ni/silica derived conversion of bio-oil surrogate guaiacol

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Carbon Resources Conversion 2024年第1期7卷 39-60页

作者： Nils Kretzschmar Oliver Busse Markus Seifert Technische universität Dresden Faculty of Chemistry and Food Chemistry01062 DresdenGermany

Replacing fossil carbon sources with green bio-oils is a promising route to switch to a sustainable chemical industry,although their high oxygen contents are *** hydrodeoxygenation is a favored route to upgrade bio-oils to renewable fuels and basic *** this work,we investigated Ni/SiO2 catalysts with differing metal dispersity in continuous mode conversion of guaiacol with a statistical experimental design for 250℃to 400℃,2 h up to 5 h time on stream(ToS)and subsequently different residence time besides other *** low temperature(250℃)promotes cyclohexanol formation from guaiacol,high temperature(400℃)inhibits hydrogenation,leading to phenol and *** medium temperature(340℃),the selectivity for cyclohexanone *** and cyclohexanone(KA-oil)are the industrial basis for polyamide ***,we clarified the role of 2-methoxycyclohexanol(2MC)in the reaction network towards KA-oil for continuous-mode *** analysis was used to predict and optimize product selectivity and yield,leading to the best yield of cyclohexanone/-ol at 327.5℃,low ToS,medium residence time,high particle dispersity,and medium hydrogen pressure(15 bar(g)).

关键词： Hydrodeoxygenation Design of experiments Bio-oil Nickel silica catalyst Continuous mode flow reactor KA-oil Cyclohexanol Cyclohexanone

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From Control Theory to Gravitational Waves

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Advances in Pure Mathematics 2024年第2期14卷 49-100页

作者： Jean-Francois Pommaret CERMICS Ecole des Ponts Paris Tech Paris France

When D:ξ→η is a linear ordinary differential (OD) or partial differential (PD) operator, a “direct problem” is to find the generating compatibility conditions (CC) in the form of an operator D1:η→ξ such that Dξ = η implies D1η = 0. When D is involutive, the procedure provides successive first-order involutive operators D1,...,Dn when the ground manifold has dimension n. Conversely, when D1 is given, a much more difficult “inverse problem” is to look for an operator D:ξ→η having the generating CC D1η = 0. If this is possible, that is when the differential module defined by D1 is “torsion-free”, that is when there does not exist any observable quantity which is a sum of derivatives of η that could be a solution of an autonomous OD or PD equation for itself, one shall say that the operator D1 is parametrized by D. The parametrization is said to be “minimum” if the differential module defined by D does not contain a free differential submodule. The systematic use of the adjoint of a differential operator provides a constructive test with five steps using double differential duality. We prove and illustrate through many explicit examples the fact that a control system is controllable if and only if it can be parametrized. Accordingly, the controllability of any OD or PD control system is a “built in” property not depending on the choice of the input and output variables among the system variables. In the OD case and when D1 is formally surjective, controllability just amounts to the formal injectivity of ad(D1), even in the variable coefficients case, a result still not acknowledged by the control community. Among other applications, the parametrization of the Cauchy stress operator in arbitrary dimension n has attracted many famous scientists (G. B. Airy in 1863 for n = 2, J. C. Maxwell in 1870, E. Beltrami in 1892 for n = 3, and A. Einstein in 1915 for n = 4).

关键词： Differential Operator Differential Sequence Killing Operator Riemann Operator Bianchi Operator Cauchy Operator Control Theory Controllability Elasticity General Relativity

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Experimental study on influence of blade angle and particle size on particle mechanics on a batch-operated single floor of a multiple hearth furnace

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Particuology 2024年第2期85卷 224-240页

作者： Max Kriegeskorte Nikoline Hilse Phil Spatz Viktor Scherer Institute for Energy Plant Technology(LEAT) Ruhr University BochumUniversitätsstraβe 15044780 BochumGermany

In industry,multiple hearth furnaces are used for the thermal treatment of particulate *** current contribution concentrates on the experimental analysis of particle mechanics for a batch-operated single floor of a multiple hearth *** particles are agitated on the circular floor by a single,rotating rabble arm equipped with three flat rabble blades of 10 mm *** blade angle,defined as the angle,which the blade is inclined against the tangential direction,is varied from 0°to 90°.A single layer of spherical polyoxymethylene(POM)particles with three different diameters(5,10 and 20 mm)is placed on the *** analyze the results,two parameters have been extracted from image analysis when the bed of particles is agitated,first,the area not covered by particles and second,the frequency distribution of the mean distance among the *** particle free surface area increases with the inclination of the *** evolution of the particle free surface area differs for the different particle *** general,the maximum particle free area for all blade angles is the largest for the 5 mm particles followed by the 20 mm *** the 10 mm particles,the particle free surface area starts for a blade angle of 0°at larger values than for the 20 mm particles but the values fall below the values for the 20 mm particles for larger blade *** reason for this behavior is discussed in *** mean distance among the particles is a parameter characterizing the length scales dominating the effects on the *** frequency distribution of the mean distance among particles provides infor-mation about the morphology of the particle bulk,for example,whether the free surface area is inter-spersed with particles.

关键词： Hearth furnace floor Particle movement Spherical particles Particle free surface area Mean distance among particles

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