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Multi-layer perceptron-based data-driven multiscale modelling of granular materials with a novel Frobenius norm-based internal variable

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2198-2218页

作者： Mengqi Wang Y.t.Feng Shaoheng Guan tongming Qu Zienkiewicz Centre for Computational Engineering Faculty of Science and EngineeringSwansea UniversitySwanseaWalesSA18EPUK Institute of theoretical and Computational Physics Graz University of TechnologyGraz8010Austria Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyClearwater BayKowloonHong KongChina

One objective of developing machine learning(ML)-based material models is to integrate them with well-established numerical methods to solve boundary value problems(BVPs).In the family of ML models,recurrent neural networks(RNNs)have been extensively applied to capture history-dependent constitutive responses of granular materials,but these multiple-step-based neural networks are neither sufficiently efficient nor aligned with the standard finite element method(FEM).Single-step-based neural networks like the multi-layer perceptron(MLP)are an alternative to bypass the above issues but have to introduce some internal variables to encode complex loading *** this work,one novel Frobenius norm-based internal variable,together with the Fourier layer and residual architectureenhanced MLP model,is crafted to replicate the history-dependent constitutive features of representative volume element(RVE)for granular *** obtained ML models are then seamlessly embedded into the FEM to solve the BVP of a biaxial compression case and a rigid strip footing *** obtained solutions are comparable to results from the FEM-DEM multiscale modelling but achieve significantly improved *** results demonstrate the applicability of the proposed internal variable in enabling MLP to capture highly nonlinear constitutive responses of granular materials.

关键词： Granular materials History-dependence Multi-layer perceptron(MLP) Discrete element method FEM-DEM Machine learning

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HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9

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Research in Astronomy and Astrophysics 2024年第1期24卷 292-299页

作者： Yan Guo C.Sengupta t.C.Scott P.Lagos Y.Luo Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China Institute of Astrophysics and Space Sciences(IA Porto) Rua das Estrelas4150-762PortoPortugal

We present resolved Giant Metrewave Radio telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a tidal Dwarf Galaxy(tDG) candidate. tDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. the quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved tDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the *** detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment.

关键词： galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM

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Photoluminescence and ratiometric thermo-response of Eu^(2+)and Eu^(3+)in BaAl_(2)B_(2)O_(7):Eu^(2+),Eu^(3+)phosphor materials

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Journal of Rare Earths 2024年第7期42卷 1240-1249,I0002页

作者： Ziyao Wang Haitao Fu Xiufeng Zhan Bo tong Guofeng Ma H.t.(Bert)Hintzen Institute of Innovative Science and technology Shenyang UniversityShenyang110044China College of Mechanical Engineering Shenyang UniversityShenyang110044China Faculty of Applied Sciences Delft University of Technology2629 JBDelftthe Netherlands

A novel Eu^(2+)-Eu^(3+)co-activated ratiometric thermo-sensitive phosphor was developed and synthesized by solid-state *** valence state of Eu,photoluminescence and thermo-sensitive performance of the phosphor prepared either in ambient air or carbothermally were investigated and *** phosphor shows high sensitivity(Sa=0.0173 K^(-1),S_(r)=0.461%/K)and superior signal discriminability(Δν∼10380 cm^(−1)).the thermo-sensitive performance is subject to the dual effects of different thermo-responses by Eu^(2+)versus Eu^(3+)combined with energy transfer from Eu^(2+)to Eu^(3+),so that the sensitivity of the phosphor in the temperature range presents a non-monotonic *** development of the BaAl_(2)B_(2)O_(7):Eu^(2+),Eu^(3+)phosphor is not only expected to be relevant for application in the field of temperature sensing,but also of reference significance for improving the sensitivity by means of energy transfer between co-activator ions over a wider temperature range of Eu^(2+)-Eu^(3+)co-activated ratiometric thermo-sensitive phosphors.

关键词： Photoluminescence Ratiometric thermo-response Phosphor Eu^(2+)/Eu^(3+) Rare earths

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Boosting the catalytic activity toward oxygen reduction via a heterostructure of porous iron oxide-decorated 2D NiO/NG nanosheets

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Journal of Energy Chemistry 2024年第6期93卷 669-681,I0016页

作者： Kakali Maiti Matthew t.Curnan Hyung Jun Kim Kyeounghak Kim Jeong Woo Han Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)PohangGyeongbuk 37673Republic of Korea Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoul 08826Republic of Korea Department of Chemical Engineering Clean-Energy Research InstituteHanyang UniversitySeoul 04763Republic of Korea CSIR-Institute of Minerals and Materials technology RRL CampusAcharya ViharBhubaneswarOdisha 751013India

As a noble metal substitute,two-dimensional(2D)hierarchical nano-frame structures have attracted great interest as candidate catalysts due to their remarkable advantages-high intrinsic activity,high electron mobility,and straightforward surface ***,they may replace Pt-based catalysts in oxygen reduction reaction(ORR)***,a simple method is developed to design hierarchical nano-frame structures assembled via 2D NiO and N-doped graphene(NG)*** procedure can yield nanostructures that satisfy the criteria correlated with improved electrocatalytic performance,such as large surface area,numerous undercoordinated atoms,and high defect ***,porous NG nanosheet architectures,featuring NiO nanosheets densely coordinated with accessible holey Fe_(2)O_(3) moieties,can enhance mesoporosity and balance *** improvements can facilitate charge transport and expose formerly inaccessible reaction sites,maximizing active site density *** functional theory(DFt)calculations reveal favored O_(2) adsorption and dissociation on Fe_(2)O_(3) hybrid structures when supported by 2D NiO and NG nanomaterials,given 2D materials donated charge to Fe_(2)O_(3) active *** systematic studies reveal that synergistic contributions are responsible for enriching the catalytic activity of Fe_(2)O_(3)@NiO/NG in alkaline media-encompassing internal voids and pores,unique hierarchical support structures,and concentrated N-dopant and bimetallic atomic ***,this work expands the toolbox for designing and synthesizing highly efficient 2D/2D shelled functional nanomaterials with transition metals,endeavoring to benefit energy conversion and related ORR applications.

关键词： N-doped graphene Holey Fe_(2)O_(3)nanocrystals NiO nanosheets High catalytic performance ORR

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Morphological and molecular description of a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii ***.(Diptera:Psychodidae)from Western Ghats,India

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Asian Pacific Journal of tropical Medicine 2024年第5期17卷 226-234页

作者： Prasanta Saini Harish Kumar Shah Mathew Jessu Sonia t tom Anns KP Amju ICMR-Vector Control Research Centre(Field Station) KottayamKeralaIndia

Objective:to report a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii ***.(Diptera:Psychodidae)from Western Ghats,***:A systematic sandfly survey was conducted in the thrissur and Kollam districts of Kerala,India using mechanical aspirators,light and sticky traps,both indoor and outdoor habitats,for a period of one *** acid barcoding of samples was performed targeting mitochondrial cytochrome oxidase I(COI)gene and sequence generated was subjected to phylogenetic ***:Sergentomyia(Neophlebotomus)ashwanii,a new sandfly species is recorded and described in this communication.A single row of 10-12 pointed teeth in the cibarium with 4-6 small denticles or fore-teeth are the key characteristics that is distinctive from other members of the subgenus *** COI barcode followed by phylogenetic analysis of the nucleotide sequence confirms that specimens of the species belong to the same taxonomic group while the genetic distance(14.2%)with the congeners established it to be a different ***:the Western Ghats'being an important biodiversity hotspot and has dearth of systematic entomological surveys on *** current study tried to fill the void and also report a new sandfly species.

关键词： Sergentomyia(Neophlebotomus)ashwanii COI barcode Western Ghats Phlebotomine sandflies

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Low crude protein formulation with supplemental amino acids for its impacts on intestinal health and growth performance of growing-finishing pigs

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1590-1606页

作者： Marcos Elias Duarte Wanpuech Parnsen Shihai Zhang Marvio L.t.Abreu Sung Woo Kim Department of Animal Science North Carolina State UniversityRaleighNC 27695USA

Background Low crude protein(CP)formulations with supplemental amino acids(AA)are used to enhance intestinal health,reduce costs,minimize environmental impact,and maintain growth performance of ***,extensive reduction of dietary CP can compromise growth performance due to limited synthesis of non-essential AA and limited availability of bioactive compounds from protein supplements even when AA requirements are ***,implementing a low CP formulation can increase the net energy(NE)content in feeds causing excessive fat *** supplementation of functional AA,coupled with low CP formulation could further enhance intestinal health and glucose metabolism,improving nitrogen utilization,and growth *** experiments were conducted to evaluate the effects of low CP formulations with supplemental AA on the intestinal health and growth performance of growing-finishing *** In Exp.1,90 pigs(19.7±1.1 kg,45 barrows and 45 gilts)were assigned to 3 treatments:CON(18.0%CP,supplementing Lys,Met,and thr),LCP(16.0%CP,supplementing Lys,Met,thr,trp,and Val),and LCPt(16.1%CP,LCP+0.05%SID trp).In Exp.2,72 pigs(34.2±4.2 kg BW)were assigned to 3 treatments:CON(17.7%CP,meeting the requirements of Lys,Met,thr,and trp);LCP(15.0%CP,meeting Lys,thr,trp,Met,Val,Ile,and Phe);and VLCP(12.8%CP,meeting Lys,thr,trp,Met,Val,Ile,Phe,His,and Leu).In Exp.3,72 pigs(54.1±5.9 kg BW)were assigned to 3 treatments and fed experimental diets for 3 phases(grower 2,finishing 1,and finishing 2).treatments were CON(18.0%,13.8%,12.7%CP for 3 phases;meeting Lys,Met,thr,and trp);LCP(13.5%,11.4%,10.4%CP for 3 phases;meeting Lys,thr,trp,Met,Val,Ile,and Phe);and LCPG(14.1%,12.8%,11.1%CP for 3 phases;LCP+Glu to match SID Glu with CON).All diets had 2.6 Mcal/kg *** In Exp.1,overall,the growth performance did not differ among *** LCPt increased(Pession in the duodenum and *** LCP and LCPt increased(Pt-1,4F2hc,and B0At exp

关键词： Amino acids Growing-finishing pigs Growth performance Intestinal health Low crude protein formulation Net energy

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tensile deformation of fine-grained Mg at 4K,78K and 298K

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Journal of Magnesium and Alloys 2024年第6期12卷 2534-2556页

作者： M.Walag A.Kula P.Noga t.tokarski G.Cios M.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland Materials Science and Engineering McMaster UniversityHamiltonCanada

the impact of grain size,ranging from 0.9μm to 9μm,on the mechanical properties of commercially pure Mg is investigated at temperatures of 4K,78K,and *** mechanisms governing plastic flow are influenced by both grain size and *** 4K and 78K,dominant deformation modes in Mg involve dislocation glide and extension twinning,regardless of grain *** interactions between basal and non-basal dislocations and dislocations with grain boundaries promote an unusually high rate of work hardening in the plastic regime,leading to premature *** yield stress follows the Hall-Petch relationshipσ_(y)∼k/√d,with the slope k increasing with decreasing *** 298K,in addition to dislocation glide and twinning,grain boundary sliding(GBS)becomes significant in samples with grain sizes below 3μm,considerably enhancing the material’s *** activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries,facilitating their absorption during sliding and *** ofσrelationship suggests that the basal slip is the dominant dislocation mode in Mg at *** grain size suppresses dislocation activity and twinning and increases GBS,resulting in lowerandσ*** conventional deformation modes coupled with enhanced GBS yields stress softening,breaking down the Hall-Petch relationship in Mg below 3μm grain size,leading to an inverse Hall-Petch *** work reports new data on the strength,ductility,work hardening and fracture behaviour,and their variations with Mg grain size across different temperature regimes.

关键词： Polycrystalline Mg Mechanical properties Deformation mechanisms Work-hardening texture evolution Cryogenic temperatures Hall-Petch relationship

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How Common can the Origin of Clusters Cha Ⅰ, Cha Ⅱ, ∈Cha and η Cha be?

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Research in Astronomy and Astrophysics 2024年第5期24卷 28-34页

作者： V.V.Bobylev A.t.Bajkova Pulkovo Astronomical Observatory St.-Petersburg 196140Russia

the trajectories of the groupings η Cha,∈Cha and Cha I,Cha II,constructed backward in time,have been *** concluded that the hypothesis about the joint formation of all four of these clusters from one molecular cloud cannot be completely ***,10–15 Myr ago,all these four clusters were located at approximately the same height above the plane of the ***,the gas-dust clouds from which all these four clusters were formed were located on one broad *** is possible that the appearance of the Cha I,Cha II,∈Cha and η Cha clusters may be associated with the impact on such a front of shock waves formed after supernova explosions in the Scorpius–Centaurus *** estimates of the kinematic ages of the clusters Cha I and Cha II are obtained as 0.12±0.19 and 0.05±0.15,*** is shown that the minimum size of the Cha I-north and Cha I-south clusters corresponded to the time of 0.55±0.24 Myr and 0.04±0.18 Myr ago,respectively,and approximately1.5 Myr ago the distance between the trajectories of these two groupings was minimal.

关键词： stars distances-stars kinematics and dynamics-galaxies star formation

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thermoluminescence characterization of natural and synthetic irradiated Ce-monazites

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Journal of Rare Earths 2024年第4期42卷 643-650页

作者： V.Correcher C.Boronat J.Garcia-Guinea J.F.Benavente t.Rivera-Montalvo CIEMAt Av.Complutense 4028040MadridSpain MNCN-CSIC J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico Nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

the thermoluminescence(tL)emission of synthetic and natural Ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each tL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic CePO_(4):Nd_(0.20),La_(0.25)).the main differences appreciated in these complex tL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on Nd and La).the behavior of the dose response in the range of 1-8 Gy is similar for both samples;the tL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,Ce3+?Ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,Frenkel defects,ODCs or NBOHCs).

关键词： thermoluminescence Kineticparameters Phosphate Ce-monazite Defects Rare earths

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Multi-scale habitat influences sprainting and group size of a freshwater-obligate smooth-coated otter(Lutrogale perspicillata) in tungabhadra Otter Conservation Reserve, India

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Ecological Processes 2024年第1期13卷 159-175页

作者： Ankit Moun P.Ramesh Kumar M.Malathi Priya t.Ramesh Riddhika Kalle Sálim Ali Centre for Ornithology and Natural History Deputy Conservator of Forests Bellary Territorial Forest Division Deputy Conservator of Forests Working Plan and Survey and Research WingBellary Territorial Forest Division Centre for Functional Biodiversity University of Kwa Zulu-Natal

Background the impact of changing land-use patterns and associated anthropogenic threats on scale-dependent habitat use of semi-aquatic mustelids in scent-marking and social behaviour can provide important insights into the habitat ecology of smooth-coated otters(Lutrogale perspicillata).Methods We sampled 180 stream segments(100–400 m) as spatial replicates of 60 1-km2 sites to record indirect evidence(i.e. spraints and mass latrine sites) and group sizes of smooth-coated otters along the tungabhadra Otter Conservation Reserve(tOCR) during the dry season. to quantify habitat, we recorded stream characteristics, riparian vegetation, and anthropogenic disturbances at the local scale, and hydro-environmental characteristics and land uses at the landscape scale. Using Markovian-chain detection and occupancy models, we assessed the multi-scale habitat use of otters in their selection of suitable areas for scent-marking based on repeated presence-absence data on spraint/latrine locations along the tOCR. We further used linear regression techniques to explore relationships between the number of individuals in smooth-coated otter group and hydro-environmental characteristics, spraint/latrine encounter rate, anthropogenic pressure, land cover, topography, and *** At the local scale, the probability of spraint deposition and group size decreased with anthropogenic disturbance while the probability of spraint detections decreased with grass cover. At the landscape scale, the probability of otter site use for spraint deposition and group sizes increased in southeast flowing streams. Spraint deposition increased with the proportion of sugarcane fields, whereas in contrast, group size decreased with proportion of sugarcane *** Our findings highlight the first empirical evidence on multi-scale habitat use of a southern Indian population of smooth-coated otters in an inland freshwater ecosystem surrounded by the scrub jungle–agriculture matrix. We sug

关键词： Presence-absence modelling Inland river Freshwater ecosystem Semi-aquatic mammal Smooth-coated otter

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