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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 histories.In 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 materials.the obtained ML models are then seamlessly embedded into the FEM to solve the BVP of a biaxial compression case and a rigid strip footing case.the obtained solutions are comparable to results from the FEM-DEM multiscale modelling but achieve significantly improved efficiency.the 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

Photoluminescence and ratiometric thermo-response of Eu2+ and Eu3+ in BaAl2B2O7:Eu2+,Eu3+ phosphor materials

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

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

A novel Eu2+-Eu3+co-activated ratiometric thermo-sensitive phosphor was developed and synthesized by solid-state reaction.the valence state of Eu,photoluminescence and thermo-sensitive performance of the phosphor prepared either in ambient air or carbothermally were investigated and discussed.the phosphor shows high sensitivity(Sa=0.0173 K-1,Sr=0.461%/K) and superior signal discriminability(Δv～10380 cm-1).the thermo-sensitive performance is subject to the dual effects of different thermoresponses by Eu2+versus Eu3+combined with energy transfer from Eu2+to Eu3+,so that the sensitivity of the phosphor in the temperature range presents a non-monotonic trend.the development of the BaAl2B2O7:Eu2+,Eu3+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 Eu2+-Eu3+co-activated ratiometric thermo-sensitive phosphors.

关键词： Eu2+/Eu3+ Phosphor Photoluminescence Rare earths Ratiometric thermo-response

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 high-metallicity.Further 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

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 functionalization.therefore,they may replace Pt-based catalysts in oxygen reduction reaction(ORR)applications.Herein,a simple method is developed to design hierarchical nano-frame structures assembled via 2D NiO and N-doped graphene(NG)nanosheets.this procedure can yield nanostructures that satisfy the criteria correlated with improved electrocatalytic performance,such as large surface area,numerous undercoordinated atoms,and high defect densities.Further,porous NG nanosheet architectures,featuring NiO nanosheets densely coordinated with accessible holey Fe_(2)O_(3) moieties,can enhance mesoporosity and balance hydrophilicity.Such improvements can facilitate charge transport and expose formerly inaccessible reaction sites,maximizing active site density utilization.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 sites.Our 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 interactions.Ultimately,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

Morphological and molecular description of a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii sp.nov.(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 sp.nov.(Diptera:Psychodidae)from Western Ghats,India.Methods: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 year.Deoxyribonucleic acid barcoding of samples was performed targeting mitochondrial cytochrome oxidase I(COI)gene and sequence generated was subjected to phylogenetic analysis.Results: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 Neophlebotomus.Mitochondrial 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 species.Conclusions:the Western Ghats'being an important biodiversity hotspot and has dearth of systematic entomological surveys on sandflies.the 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

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 process.the 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 mechanism.Each 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

Detailed seismic zoning of the East Kazakhstan region in the Republic of Kazakhstan

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Geodesy and Geodynamics 2024年第2期15卷 156-165页

作者： Natalya V.Silacheva N.P.Stepanenko O.K.Kurilova A.D.Kudabayeva A.t.Danabayeva Institute of Seismology Ministry of Emergency SituationsAlmaty 050060Kazakhstan

Kazakhstan is currently drafting new construction regulations that comply with the major provisions of the Eurocodes.Such regulations are created on the basis of seismic zoning maps of various degrees of detail,developed by our Institute of Seismology using a new methodological approach for Kazakhstan.the article is about creating the first normative map of the Detailed Seismic Zoning on a probabilistic foundation for the Republic of Kazakhstan’s East Kazakhstan region.We carried out the probabilistic assessment of seismic hazard using a methodology consistent with the main provisions of Eurocode 8and updated compared with that used in developing maps of Kazakhstan’s General Seismic Zoning and seismic microzoning of Almaty.the most thorough and current data accessible for the area under consideration were combined with contemporary analytical techniques.Updates have been done to not only the databases being used but also the way seismic sources were shown,including active faults now.On a scale of 1:1000000,precise seismic zoning maps of the East Kazakhstan region were created for two probabilities of exceedance:10%and 2%in 50 years in terms of peak ground accelerations and macroseismic intensities.the obtained seismic hazard distribution is generally consistent with the General Seismic Zoning of Kazakhstan’s previous findings.However,because active faults were included and a thoroughly revised catalog was used,there are more pronounced zones of increased danger along the fault in the western part of the region.In the west of the territory,acceleration values also increased due to a more accurate consideration of seismotectonic conditions.Zoning maps are the basis for developing new state building regulations of the Republic of Kazakhstan.

关键词： Probabilistic seismic hazard assessment Detailed seismic zoning Peak ground acceleration Microseismical intensity

Aerodynamics of a tandem-Bladed Axial Compressor Rotor under Circumferential Distortion at Different Rotational Speeds

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Journal of thermal Science 2024年第4期33卷 1340-1356页

作者： Amit KUMAR Jerry t.JOHN A.M.PRADEEP R.A.D.AKKERMANS Dragan KOZULOVIC Department of Aerospace Engineering Indian Institute of Technology Bombay Department of Automotive and Aeronautical Engineering Hamburg University of Applied Sciences Institute of Jet Propulsion Bundeswehr University Munich

For most aircraft engines,inflow distortion is inevitable.Inflow distortion is known to degrade the aerodynamic performance and stable operating limits of a compressor.tandem rotor configuration is an arrangement that effectively controls the growth of the boundary layer over the suction surface of the blade.therefore,a higher total pressure rise can be achieved through this unconventional design approach involving the splitting of the blade into forward and aft sections.It is expected that the effect of inlet flow distortion would be more severe for a tandem-rotor design due to the greater flow turning inherent in such designs.However,this aspect needs to be thoroughly examined.the present study discusses the effect of circumferential distortion on the tandem-rotor at different rotational speeds.Full-annulus RANS simulations using ANSYS CFX are used in the present study.the performance of the rotor at a particular flow coefficient and different rotational speeds is compared.the total pressure and efficiency are observed to drop at lower mass flow rates under the influence of circumferential distortion.the loss region in each blade passage is mainly associated with the blade wake,tip leakage vortex,secondary flow,and boundary layer.However,their contribution varies from passage to passage,particularly in the distorted sector.At the lower span,the wake width is found to be higher than that at a higher span.Due to the redistribution of the mass flow,the circumferential extent reduces at a higher span.In the undistorted sector,the strength of the tip leakage vortex is significantly higher at the design rotational speed than at lower speeds.the distortion near the tip region promotes an early vortex breakdown even at the design operating condition.this adversely affects the total pressure,efficiency,and stall margin.Under clean flow conditions,this phenomenon is only observed near the stall point.At the design operating condition,the breakdown of the forward rotor tip leakage vortex is detected in four blade passages

关键词： tandem rotor circumferential distortion loss tip leakage vortex vortex breakdown diffusion factor aerodynamics of compressor blade

Mechanism of action, benefits, and research gap in fermented soybean meal utilization as a high-quality protein source for livestock and poultry

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Animal Nutrition 2024年第1期16卷 130-146页

作者： Modinat t.Lambo Haokai Ma Haosheng Zhang Peng Song Hongxiang Mao Guowen Cui Baisheng Dai Yang Li Yonggen Zhang College of Animal Science and technology Northeast Agricultural University Wilmar (Shanghai) Biotechnology Research and Development Center Co. Ltd College of Electrical Engineering and Information Northeast Agricultural University

Animal nutritionists have incessantly worked towards providing livestock with high-quality plant protein feed resources.Soybean meal (SBM) has been an essential and predominantly adopted vegetable protein source in livestock feeding for a long time;however,several SBM antinutrients could potentially impair the animal's performance and growth,limiting its use.Several processing methods have been employed to remove SBM antinutrients,including fermentation with fungal or bacterial microorganisms.According to the literature,fermentation,a traditional food processing method,could improve SBM's nutritional and functional properties,making it more suitable and beneficial to livestock.the current interest in health-promoting functional feed,which can enhance the growth of animals,improve their immune system,and promote physiological benefits more than conventional feed,coupled with the ban on the use of antimicrobial growth promoters,has caused a renewed interest in the use of fermented SBM (FSBM) in livestock diets.this review details the mechanism of SBM fermentation and its impacts on animal health and discusses the recent trend in the application and emerging advantages to livestock while shedding light on the research gap that needs to be critically addressed in future studies.FSBM appears to be a multifunctional high-quality plant protein source for animals.Besides removing soybean antinutrients,beneficial bioactive peptides and digestive enzymes are produced during fermentation,providing probiotics,antioxidants,and immunomodulatory effects.Critical aspects regarding FSBM feeding to animals remain uncharted,such as the duration of fermentation,the influence of feeding on digestive tissue development,choice of microbial strain,and possible environmental impact.

关键词： Soybean meal Protein feed Fermentation Microorganism Livestock