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Proposed numerical and machine learning models for fiber-reinforced polymer concrete-steel hollow and solid elliptical columns

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frontiers of Structural and Civil Engineering 2024年第8期18卷 1169-1194页

作者： Tang QIONG Ishan JHA Alireza BAHRAMI Haytham f.ISLEEM Rakesh KUMAR Pijush SAMUI School of Applied Technologies Qujing Normal UniversityQujing 655011China Department of Civil Engineering Indian Institute of Technology-BHUVaranasi 221005India Department of Building Engineering Energy Systems and Sustainability ScienceFaculty of Engineering and Sustainable DevelopmentUniversity of GävleGävle 80176Sweden Department of Civil Engineering National Institute of Technology-PatnaPatna 800005India

This study employs a hybrid approach,integrating finite element method(fEM)simulations with machine learning(ML)techniques to investigate the structural performance of double-skin tubular columns(DSTCs)reinforced with glass fiber-reinforced polymer(GfRP).The investigation involves a comprehensive examination of critical parameters,including aspect ratio,concrete strength,number of GfRP confinement layers,and dimensions of steel tubes used in DSTCs,through comparative analyses and parametric *** ensure the credibility of the findings,the results are rigorously validated against experimental data,establishing the precision and trustworthiness of the *** present research work examines the use of the columns with elliptical cross-sections and contributes valuable insights into the application of fEM and ML in the design and evaluation of structural systems within the field of structural engineering.

关键词： elliptical column fiber-reinforced polymer machine learning finite element method ABAQUS

SnRK1a1, a new player in the sucrose-Opaque2 network during endosperm filling

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Molecular Plant 2024年第8期17卷 1172-1174页

作者： Kelly Mayrink Balmant Marcio f.R.Resende Jr. Horticultural Sciences Department University of FloridaGainesvilleFLUSA

Maize(Zea mays)endosperm is an important food source for humans and *** addition,it is considered an excellent model for research on seed development because of its relatively large size for both embryo and endosperm compared to those of other crop species,such as rice(Oryza sativa)and wheat(Triticum aestivum).After double fertilization,early maize endosperm development includes three stages:(i)a multinucleate coenocyte stage;(i)a cellularization stage,in which the cellular endosperm is formed;and(ii)a stage of differentiation into distinct *** early differentiation,four major cell types with specific functions differentiate within the endosperm:starchy endosperm,aleurone layer,basal endosperm transfer layer(BETL),and embryo surrounding *** subaleurone,conducting zone,basal intermediate zone,and endosperm adjacent to scutellum arise in late differentiation(Sabelli and Larkins 2009).After the main cell types are established,maize endosperm undergoes intensive cell proliferation,which marks the transition to the endosperm-filling *** the endosperm-flling stage,the maternal sucrose products are transported to seeds through the BETL region,where they will act as the main carbon substrate for storage products such as starch and proteins(Chen et al.,2023).In fact,the endosperm of maize seeds accounts for approximately 90%of the total grain weight,serving as an important nutrient reservoir(flint-Garcia et al.,2009).

关键词： endosperm reservoir flint

Effects of dust controls on respirable coal mine dust composition and particle sizes:case studies on auxiliary scrubbers and canopy air curtain

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International Journal of Coal Science & Technology 2024年第3期11卷 86-101页

作者： f.Animah C.Keles W.R.Reed E.Sarver Department of Mining and Minerals Engineering Virginia Polytechnic Institute&State UniversityBlacksburgVAUSA National Institute of Occupational Safety and Health(NIOSH) PittsburghPAUSA

Control of dust in underground coal mines is critical for mitigating both safety and health *** decades,the National Institute of Occupational Safety and Health(NIOSH)has led research to evaluate the effectiveness of various dust control technologies in coal *** studies have included the evaluation of auxiliary scrubbers to reduce respirable dust downstream of active mining and the use of canopy air curtains(CACs)to reduce respirable dust in key operator *** detailed dust characterization was not a focus of such studies,this is a growing area of *** preserved filter samples from three previous NIOSH studies,the current work aims to explore the effect of two different scrubbers(one wet and one dry)and a roof bolter CAC on respirable dust composition and particle size *** this,the preserved filter samples were analyzed by thermogravimetric analysis and/or scanning electron microscopy with energy dispersive *** indicate that dust composition was not appreciably affected by either scrubber or the ***,the wet scrubber and CAC appeared to decrease the overall particle size *** an effect of the dry scrubber was not consistently observed,but this is probably related to the particular sampling location downstream of the scrubber which allowed for significant mixing of the scrubber exhaust and other return *** from the insights gained with respect to the three specific dust control case studies revisited here,this work demonstrates the value of preserved dust samples for follow-up investigation more broadly.

关键词： Respirable dust Dust control SEM–EDX Scrubber Canopy air curtain Silica

Converting TREx-RGB green-channel data to 557.7 nm auroral intensity:Methodology and initial results

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Earth and Planetary Physics 2024年第1期8卷 258-274页

作者： Jun Liang D.M.Gillies E.Spanswick E.f.Donovan University of Calgary CalgaryT2N 1N4Canada

The recently deployed Transition Region Explorer(TREx)-RGB(red-green-blue)all-sky imager(ASI)is designed to capture“true color”images of the aurora and *** the 557.7 nm green line is usually the brightest emission line in visible auroras,the green channel of a TREx-RGB camera is usually dominated by the 557.7 nm *** this rationale,the TREx mission does not include a specific 557.7 nm imager and is designed to use the RGB green-channel data as a proxy for the 557.7 nm *** this study,we present an initial effort to establish the conversion ratio or formula linking the RGB green-channel data to the absolute intensity of 557.7 nm auroras,which is crucial for quantitative uses of the RGB *** illustrate two approaches:(1)through a comparison with the collocated measurement of green-line auroras from the TREx spectrograph,and(2)through a comparison with the modeled green-line intensity according to realistic electron precipitation flux measurements from low-Earth-orbit satellites,with the aid of an auroral transport *** demonstrate the procedures and provide initial results for the TREx-RGB ASIs at the Rabbit Lake and Lucky Lake *** RGB response is found to be *** conversion ratios or formulas between RGB green-channel data and the green-line auroral intensity are given and can be applied immediately by TREx-RGB data *** methodology established in this study will also be applicable to the upcoming SMILE ASI mission,which will adopt a similar RGB camera system in its deployment.

关键词： TREx RGB green-line aurora auroral transport model

Assembly structures of coastal woody species of eastern South America:Patterns and drivers

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Plant Diversity 2024年第5期46卷 611-620页

作者： Eduardo Vinícius da Silva Oliveira Myrna friederichs Landim Sidney f.Gouveia Graduate Program in Ecology and Conservation Federal University of SergipeSão CristovãoSergipeBrazil National Institute of Science and Technology Ecology Evolution and Conservation of Biodiversity(INCT-EECBio)GoiâniaGoiasBrazil Department of Biology Federal University of SergipeSão CristóvãoSergipeBrazil Department of Ecology Federal University of SergipeSão CristóvãoSergipeBrazil

Tropical regions have provided new insights into how ecological communities are *** dry coastal communities,water stress has been hypothesized to determine plant assembly structure by favoring preadapted lineages from neighboring ecosystems,consistent with functional ***,it is unclear whether this hypothesis is sufficient to explain how coastal communities in tropical ecosystems are ***,we test whether water stress or other factors drive community assembly in woody plant communities across the coastal zone of Brazil,a tropical *** characterized functional and phylogenetic structures of these communities and determined the underlying environmental factors(e.g.,water stress,historical climate stability,edaphic constraints,and habitat heterogeneity)that drive their community *** of coastal woody species show geographically varied patterns,including stochastic arrangements,clustering,and overdispersion of species relative to their traits and phylogenetic *** complexity,water vapor pressure,and soil nutrient availability best explained the gradient in the functional *** deficit,water vapor pressure,and soil organic carbon were the best predictors of variation in phylogenetic *** results support the water-stress conservatism hypothesis on functional and phylogenetic structure,as well as the effect of habitat heterogeneity on functional structure and edaphic constraints on functional and phylogenetic *** effects are associated with increased phenotypic and phylogenetic divergence of woody plant assemblages,which is likely mediated by abiotic filtering and niche opportunities,suggesting a complex pattern of ecological assembly.

关键词： Brazil Completeness Clustering Restinga vegetation Water constraints

Tracking the Ti^(4+)substitution in phlogopite by spectroscopic imaging:A tool for unravelling the growth of micas at HP-HT conditions

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Geoscience frontiers 2024年第3期15卷 1-13页

作者： G.Della Ventura N.El Moutaouakkil B.Boukili S.Bernardini A.Sodo L.Pronti M.Cestelli-Guidi f.Holtz f.Lucci Dipartimento di Scienze UniversitàRoma TreRomaItaly INfN-LNf via Fermi 200040 FrascatiRomaItaly INGV Via di Vigna Murata 60500143 RomaItaly Laboratory of Géosciences Water and Environment.Department of Earth Sciences.Faculty of SciencesUniversity Mohammed VRabatMorocco Leibnitz Universität Hannover Institute of MineralogyCallinstr 330167 HannoverGermany Dipartimento di Scienze della Terra e Geoambientali Universitàdi Bari“Aldo Moro”BariItaly

Phlogopite solid-solutions have a wide pressure-temperature(P-T)stability field and are ubiquitous in a wide variety of geological settings,from deep lithosphere magmatic environments to upper crust metamorphic *** composition represents therefore a valuable physical-chemical archive and may provide important information regarding its crystallization and the petrogenesis of the *** this paper we examine the phlogopite phenocrysts from the well-known fort Regent mica-bearing lamprophyre minette from ***(Island of Jersey,UK).Phlogopite phenocrystals from lamprophyres generally show normal-step and continuous compositional zoning,however those from the fort Regent minette show a peculiar texture characterized by dark brown high-Ti(average TiO_(2)≈8.5 wt.%)cores enveloped by euhedral low-to mid-amplitude zonation due to oscillatory contents in Ti,fe and ***-barometry modelling based on biotite-only composition yields relatively high P-T estimates(T≈970±54℃at P≈0.73±0.13 GPa)for cores whereas lower values(T≈790±54℃at P≈0.29±0.13 GPa)are obtained for the outer *** temperatures(T≈1075±54℃)but extremely high and anomalous pressure values(P≈1.82±0.13 GPa)are obtained for the yellowish inner *** combination of electron micro probe(EMP)analysis and single-crystal infra-red(fTIR)imaging in the OH-stretching region shows that the exceptional and oscillatory Ti contents are due to the Ti-vacancy substitution,typical of crystallization and growth processes of HP/HT *** imaging provides additional insight for this process,confirming the dominant dioctahedral nature for the Ti-fe-rich cores and outer *** of thermobaric estimates obtained from the phlogopite compositiononly model,based on the fine-scale compositional evolution,shows that pressure-temperature values from low-Ti high-Mg domains should be carefully evaluated because the substitution mechanisms during the dark mica growth are not univocal

关键词： Ti-phlogopite Jersey minette(UK) Ti-substitution fTIR imaging Raman imaging Thermobarometric modelling

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL J.CHOI S.f.SHAH C.LEE S.LEE Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyCo_(z)O_(2)(x>0.8)(NMC)

Asymmetric reversible structural switching of a diene coordination polymer promoted by UV-visible light

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Science China Chemistry 2024年第2期67卷 536-541页

作者： Yong Wang Qiaoqiao Zhang Yong-Yong Cao Qi Liu Brendan f.Abrahams Jian-Ping Lang College of Chemistry Chemical Engineering and MaterialsSoochow UniversitySuzhou215123China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai200032China College of Biological Chemical Science and EngineeringJiaxing UniversityJiaxing314001China School of Chemistry University of MelbourneVictoria3010Australia

In natural and artificial systems,reversible reactions are commonly asymmetric with respect to the time scale and nature of the stimuli which drive the forward and backward *** applications for which switching behavior is required,it is desirable that the reversible reaction goes as close to symmetric as possible;however,such systems are ***,we report an example of ultraviolet(UV)-visible light-regulated asymmetric reversible structural switching involving a diene-based coordination polymer,CP1 and its monocyclobutane product,*** is possible to cycle at least ten times through a forward [2+2] photocycloaddition reaction and the reverse,photocleavage reaction.A single cycle can be completed within a few *** transformation is accompanied by fast and distinct fluorescence changes,arising from optimisation of the reaction *** functional theory calculations allow rationalisation of the asymmetric reversible transformation between CP1 and CP1a rather than between CP1 and its dicyclobutane product *** work provides a clear illustration of reversible structural switching which approaches symmetric behaviour with respect to reaction rate and *** insights gained from this work also assist in the design of fast,reversible switching materials.

关键词： asymmetrical reversible structural switching coordination polymer photocycloaddition UV-visible light-controlled fluorescence switching

Modelling the brittle rock failure by the quaternion-based bonded-particle model in DEM

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第2期3卷 87-95页

作者： Tao Zhao Philip E.f.Collins Department of Civil and Environmental Engineering Brunel University LondonLondonUB83PHUnited Kingdom

This paper presents an investigation of brittle rock failure by the quaternion-based bonded-particle model in discrete element method(DEM).Unlike traditional approaches that utilize Euler angles or rotation matrices,this model employs unit quaternions to represent the spatial rotations of *** method simplifies the rep-resentation of 3D rotations,providing a more intuitive framework for modelling complex interactions in granular *** numerical model was validated by the uniaxial compression tests on rock,with good agreement with well-documented experimental data in terms of the rock uniaxial compression strength(UCS)and failure *** loading,the rock sample demonstrated a linear-elastic response at an axial strain of smaller than 0.45%.However,as internal bond breakage accumulated,this linear relationship weakened,and the stress-strain curve began to deviate from its initial linear *** bond breakage and the overall deformation of the rock were primarily controlled by the shear bonding *** UCS was achieved at an axial strain of 0.625%,at which point the internal shear bonding force chains were predominantly aligned *** brittle failure occurred when the internal damage of solids nucleated to form an interconnected failure plane,accompanied by a sharp rise in the internal damage *** area of failure plane increased with the loading strain rate,gradually transforming the failure pattern from the local damage to a complete fragmentation.

关键词： Brittle failure Quaternion DEM bonded model Uniaxial compression test Rate dependent Internal damage