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Magnetic flux ropes in the solar corona: structure and evolution toward eruption

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Research in Astronomy and Astrophysics 2020年第10期20卷 287-328页

作者： rui liu CAS Key Laboratory of Geospace Environment Department of Geophysics and Planetary SciencesUniversity of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Comparative Planetology Hefei 230026China Mengcheng National Geophysical Observatory University of Science and Technology of ChinaMengcheng 233500China

Magnetic flux ropes are characterized by coherently twisted magnetic field lines,which are ubiquitous in magnetized *** the core structure of various eruptive phenomena in the solar atmosphere,flux ropes hold the key to understanding the physical mechanisms of solar eruptions,which impact the heliosphere and planetary *** strongest disturbances in the Earth’s space environments are often associated with large-scale flux ropes from the Sun colliding with the Earth’s magnetosphere,leading to adverse,sometimes catastrophic,space-weather ***,it remains elusive as to how a flux rope forms and evolves toward eruption,and how it is structured and embedded in the ambient *** present paper addresses these important questions by reviewing current understandings of coronal flux ropes from an observer’s perspective,with an emphasis on their structures and nascent evolution toward solar eruptions,as achieved by combining observations of both remote sensing and in-situ detection with modeling and *** paper highlights an initiation mechanism for coronal mass ejections(CMEs)in which plasmoids in current sheets coalesce into a’seed’flux rope whose subsequent evolution into a CME is consistent with the standard model,thereby bridging the gap between microscale and macroscale dynamics.

关键词： magnetic fields magnetic reconnection Sun:magnetic fields Sun:corona Sun:coronal mass ejections(CMEs) Sun:flares Sun:filaments,prominences

Lightweight privacy-preserving truth discovery for vehicular air quality monitoring

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Digital Communications and Networks 2023年第1期9卷 280-291页

作者： rui liu Jianping Pan Department of Computer Science University of VictoriaVictoriaBCV8P 5C2Canada

Air pollution has become a global concern for many *** crowdsensing systems make it possible to monitor air quality at a fine *** better utilize the sensory data with varying credibility,truth discovery frameworks are ***,in urban cities,there is a significant difference in traffic volumes of streets or blocks,which leads to a data sparsity problem for truth *** the privacy of participant vehicles is also a crucial *** first present a data masking-based privacy-preserving truth discovery framework,which incorporates spatial and temporal correlations to solve the sparsity *** further improve the truth discovery performance of the presented framework,an enhanced version is proposed with anonymous communication and data *** frameworks are more lightweight than the existing cryptography-based *** also evaluate the work with simulations and fully discuss the performance and possible extensions.

关键词： Privacy preserving Truth discovery Crowdsensing Vehicular networks

Instance-sequence reasoning for video question answering

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Frontiers of Computer Science 2022年第6期16卷 93-101页

作者： rui liu Yahong HAN College of Intelligence and Computing Tianjin UniversityTianjin300350China Tianjin Key Lab of Machine Learning Tianjin UniversityTianjin300350China

Video question answering(Video QA)involves a thorough understanding of video content and question language,as well as the grounding of the textual semantic to the visual content of ***,to answer the questions more accurately,not only the semantic entity should be associated with certain visual instance in video frames,but also the action or event in the question should be localized to a corresponding temporal *** turns out to be a more challenging task that requires the ability of conducting reasoning with correlations between instances along temporal *** this paper,we propose an instance-sequence reasoning network for video question answering with instance grounding and temporal *** our model,both visual instances and textual representations are firstly embedded into graph nodes,which benefits the integration of intra-and ***,we propose graph causal convolution(GCC)on graph-structured sequence with a large receptive field to capture more causal connections,which is vital for visual grounding and instance-sequence ***,we evaluate our model on TVQA+dataset,which contains the groundtruth of instance grounding and temporal localization,three other Video QA datasets and three multimodal language processing *** experiments demonstrate the effectiveness and generalization of the proposed ***,our method outperforms the state-of-the-art methods on these benchmarks.

关键词： video question answering instance grounding graph causal convolution

Minimal and Maximal Unconditional Bases with Respect to Framings

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Acta Mathematica Sinica,English Series 2013年第12期29卷 2295-2304页

作者： rui liu Department of Mathematics and LPMC Nankai University

This paper studies framings in Banach spaces, a concept raised by Casazza, Han and Larson, which is a natural generalization of traditional frames in Hilbert spaces and unconditional bases in Banach spaces. The minimal unconditional bases and the maximal unconditional bases with respect to framings are introduced. Our main result states that, if （xi, fi） is a framing of a Banach space X, and （eimin） and （eimax） are the minimal unconditional basis and the maximal unconditional basis with respect to （xi, fi）, respectively, then for any unconditional basis （ei） associated with （xi, fi）, there are A,B 〉 0 such that A｜｜i=1∑∞aieimin｜｜≤｜｜i=1∑∞aiei｜｜≤B｜｜i=1∑∞aieimax｜｜ for all （ai） ∈ c00.It means that for any framing, the corresponding associated unconditional bases have common upper and lower bounds.

关键词： Associated unconditional basis framing maximal unconditional basis minimal unconditional basis

The role of hydrostatic pressure on the metal corrosion in simulated deep-sea environments—a review

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Journal of Materials Science & Technology 2022年第17期112卷 230-238页

作者： rui liu Li liu Fuhui Wang Shenyang National Laboratory for Materials Science Northeastern UniversityNO.3-11 Wenhua RoadShenyang 110819China

This paper reviewed the corrosion behavior of metals in simulated deep-water environments and briefly discussed the effect of hydrostatic pressure on the different corrosion types for the active and the passive alloys.A consensus on the corrosion mechanism is that hydrostatic pressure accelerates the dissolution kinetics,changes the chemical compositions of the product layer or passive films,and promotes the adsorption of Cl^(-)on the metal *** addition,a newly-developed mechanism that hydrostatic pressure facilitates the dissolution process by thinning the electric double layer was reviewed,the synergistic effect of hydrostatic pressure and tensile stress on the stress corrosion cracking was discussed,and the modified coating with chemical bonding interface to prolong the service life in this environment was introduced.

关键词： Corrosion Hydrostatic pressure Deep-sea environments

Experimental Study on Diesel Spray and Flame Asymmetry Characteristics of Dual-Orifice Nozzles for a Medium-Speed Engine

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Journal of Thermal Science 2025年第1期 303-322页

作者： JU Dehao liu rui ZHENG Liang DENG Jiahui ZHANG Wenzheng HUO Jinlu HUANG Li Shanghai Marine Diesel Engine Research Institute National Key Laboratory of Marine Engine Science and Technology Key Laboratory for Power Machinery and Engineering Ministry of EducationShanghai Jiao Tong University

The asymmetry of the multi-orifice spray will cause uneven heat load of the marine diesel engine,thereby affecting its working performance and service ***,an in-depth understanding of the spray and flame characteristics of multi-orifice nozzles will guide the optimization of the nozzle structure,needle design and diesel atomization and combustion *** this reason,four groups of dual-orifice nozzles with different hole diameters(0.1-0.55 mm) and mass flow rates covering the typical marine medium-speed diesel injections are designed and customized,and the constant volume chamber(CVC) with high temperature and pressure is used to simulate the actual in-cylinder working conditions of the diesel engine for the spray visualization *** study the asymmetry of the fuel sprays discharged from a diesel injector,the multi-orifice nozzle is simplified as a dual-orifice nozzle in this *** with X-ray Computed Tomography(CT) imaging technology,the influences of the nozzle internal structure on the spray and flame asymmetry are studied in the constructed supercritical *** is found that the asymmetry of the inlet angle and the equivalent length-diameter ratio is positively correlated with the inconsistency of the dual *** an increase in the injection pressure and nozzle diameter,the asymmetry of the dual spray becomes more pronounced,resulting in greater disparities in the ignition delay times and ignition positions of the two ***,the increase in nozzle diameter also leads to combustion instability,resulting in a flame with a serrated *** the increase of ambient temperature,the proportion of liquid phase in the jet decreases and the relative density of spray front decreases.

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The Influence of Co Addition on Phase Transformation Behavior and Mechanical Properties of TiNi Alloys

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Chinese Journal of Aeronautics 2007年第2期20卷 153-156页

作者： JING rui-rui liu Fu-shun School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

The influences of Co-addition on phase transformation behavior and mechanical properties of TiN/alloys were investigated. Resuits indicate that, as a substitute for Ni, Co added to TiNi alloys can dramatically decrease the martensite transformation temperature, and R phase transformation and martensite transformation are accordingly separated. When Co-content reach 10 at.%, the martensite transformation temperature is lower than that of liquid nitrogen. During deformation at room temperature, Ti50Ni48Co2 alloy exhibits good ductility with a lower stress plateau caused by stress-induced martensite and martensite reorientation.

关键词： TiNiCo shape memory alloy martensite transformation mechanical property

Shitsan Pai:the establishment of the first biophysics department in the world

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Protein & Cell 2019年第10期10卷 701-704页

作者： rui liu Department for the History of Science and Scientific Archaeology University of Science and Technology of ChinaHefei 230026China

Since the birth of New China,it suffered from many internal and external problems,and thousands of things waited to be done(Fig.1).In order to improve its status in the intemational comm unity,and con solidate its national defe nse,the Chinese government decided to develop nuclear weapons and aerospace *** 1954,the Soviet Union leader Khrushchev had an official visit to *** his visit,Chairman Mao Zedong put forward a request to Moscow to help China manufacture nuclear weapons.

关键词： visit Chairman Moscow

Construction of multifunctional lanthanum manganese mixed nanoparticles mediated by ionic liquids for selective aerobic oxidation of cyclohexane

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Rare Metals 2024年第5期43卷 2205-2221页

作者： Hao Li rui-rui Zhang Ke-Xin Li Shuang Wei Yu-Mei liu rui-Xia liu Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Selective oxidation of alkanes to produce highvalue chemicals is an essential strategy and means to realize efficient utilization of *** this work,a strategy of lanthanum manganese mixed metal oxides(LMMO)regulated via a facile ionic liquid(IL)-assisted hydrothermal method was proposed to construct the multifunctional catalysts,which exhibited excellent catalytic performance in the selective aerobic oxidation of *** 8.9%cyclohexane conversion with 90%KA oi(cyclohexanol and cyclohexanone)selectivity was achieved over the optimal LMMO catalyst under mild *** effects of anion type,carbon chain length and concentration of ILs on the structure and properties of catalysts were investigated through various characterizations,indicating the structure-directing and template effect of ILs on the multifunctional *** formation of self-assembled spherical nanoparticles followed the"dissolution-nucleation-proliferation"mechanism with the introduction of 1-butyl-3-methylimidazolium hydrogen sulfate,ascribing the synergistic effect between the microenvironment of ILs and the hydrothermal ***,the high reactive oxygen concentration redox capacity,and suitable basic sites of LMMO catalysts mediated by ILs enhance the activation of C-H bonds and molecular oxygen,simultaneously influencing the adsorption and desorption of the substrate.A comprehensive understanding of the high KA oil selectivity and radical reaction mechanism was elucidated based on in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and radical trapping *** recycling and regeneration experiments further illuminated that the removal of adsorbed cyclohexanone acting on the LMMO catalyst was the key to achieve high KA oil selectivity.

关键词： Ionic liquids Nanoparticle Multifunctional catalyst Cyclohexane oxidation