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Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

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Journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： Y.B.Zhang S.J.Song f.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3D CPfE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).By detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic *** by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

Sb^(3+)and Sm^(3+)co-doped lead-free Cs_(2)NaInCl_(6)double perovskite nanocrystals for single-component cold white emitter

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Journal of Rare Earths 2024年第9期42卷 1646-1651,I0001页

作者： Biao Zhou Xiangtong Zhang Ranran Hu Ruixue Hou william w.Yu Key Laboratory for Special functional Materials of Ministry of Education National&Local Joint Engineering Research Centre for High-Efficiency Display and Lighting TechnologySchool of Materials and EngineeringCollaborative Innovation Centre of Nano Functional Materials and ApplicationsHenan UniversityKaifeng475000China School of Chemistry and Chemical Engineering Shandong UniversityJinan250100China

Metal halide perovskites exhibit promising prospect in light-emitting diodes,solar cells,photodetectors and ***,the workhorse of metal halide perovskites relies on toxicity lead element,which severely damages human body and *** lead-free perovskites,Cs_(2)NaInCl_(6)double perovskite is one of the most promising candidates because of its great stability and easy synthesis,but suffers inadequate optical ***,we doped Sb^(3+)and Sm^(3+)into Cs_(2)NaInCl_(6)nanocrystals by a hot injection ***_(2)NaInCl_(6):Sb^(3+)exhibits blue emission at 447 ***_(2)NaInCl_(6):Sm^(3+),Sb^(3+)nanocrystals simultaneously generate the blue emission of Sb^(3+)and the multiple emissions of Sm^(3+)at 565,602,650 and 710 *** the increase of Sm^(3+)feed ratio,the emission color of Cs_(2)NaInCl_(6):Sm^(3+),Sb^(3+)gradually moves to cold white region at(0.27,0.28)in CIE chromaticity diagram and correlated color temperature of 11840 *** work shows the potential application of Cs_(2)NaInCl_(6):Sm^(3+),Sb^(3+)nanocrystals as a single-component cold white emitter.

关键词： Lead-free Double perovskites Single component white emitter Doping Rare earths

Plant grafting:Molecular mechanisms and applications

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Molecular Plant 2024年第1期17卷 75-91页

作者： Ming feng frauke Augstein Abdul Kareem Charles w.Melnyk Department of Plant Biology Linnean Center for Plant BiologySwedish University of Agricultural SciencesAlmas allé575651 UppsalaSweden

People have grafted plants since antiquity for propagation,to increase yields,and to improve stress *** cutting and joining of tissues activates an incredible regenerative ability as different plants fuse and grow as *** over a hundred years,people have studied the scientific basis for how plants ***,new techniques and a deepening knowledge of the molecular basis for graft formation have allowed a range of previously ungraftable combinations to ***,we review recent developments in our understanding of graft formation,including the attachment and vascular formation *** analyze why plants graft and how biotic and abiotic factors influence successful *** also discuss the ability and inability of plants to graft,and how grafting has transformed both horticulture and fundamental plant *** our knowledge about plant grafting improves,new combinations and techniques will emerge to allow an expanded use of grafting for horticultural applications and to address fundamental research questions.

关键词： plant grafting regeneration mobile molecules tissue adhesion vascular differentiation stress tolerance

On the analytical solution of transient friction in channel flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： f.J.GARCíA-GARCíA P.fARINAS-ALVARINO Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULf)and the purely turbulent component(PTC),and the contributions are analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant for plane-parallel laminar flows is reported,and the role of the time constant in a turbulent mean flow is *** is shown that the time constant is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

Effective yield strength of a saturated porous medium with a spheroidal meso-pore and spherical micro-pores

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第1期3卷 97-104页

作者： w.Q.Shen College of Architecture and Energy Engineering Wenzhou University of TechnologyWenzhou325000China Department of Civil Engineering Polytech LilleUniversity of LilleFrance

A macroscopic yield criterion has been derived in the present work for a double saturated porous medium with a spheroidal pore at the mesocale and spherical pores at the *** two types of pores are well separated at two different *** meso spheroidal pore saturated by a pore pressure which is different from the one in the micro spherical pores.A Drucker-Prager type criterion is adopted for the solid phase at the microscopic scale to describe its asymmetric behavior between tension and *** methodology to formulate this criterion is based on the limit analysis approach of a spheroidal volume containing a confocal spheroidal pore subjected to a uniform strain rate boundary *** matrix at the mesoscopic scale obeys to a general elliptic yield *** on a two-step homogenization step,the influence of meso-pore shape(spherical,prolate or oblate),micro-porosity,meso-porosity and the effect of pore pressures at different scales are taken into account explicitly by this macroscopic yield criterion.

关键词： Double porous materials Saturated Spheroidal pore Macroscopic yield criterion Plasticity Gurson-type model

Are we ready to use new endoscopic scores for ulcerative colitis?

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world Journal of Gastroenterology 2024年第10期30卷 1466-1469页

作者： Rodrigo Quera Paulina Núñez f Universidad de los Andes Inflammatory Bowel Disease ProgramClinica Universidad de los AndesDigestive Disease CenterSantiago 7600976RMChile Digestive Disease Center Inflammatory Bowel Disease ProgramClínica Universidad de los AndesSantiago 7620157Chile Department of Gastroenterology Universidad de Chile-Hospital San Juan de DiosSantiago 770123Chile

for ulcerative colitis(UC),the variability in inflammatory activity along the colon poses a challenge in *** focus on achieving endoscopic healing in UC is evident,where the UC Endoscopic Index of Severity and Mayo Endoscopic Subscore are commonly used for ***,these indices primarily consider the most severely affected *** et al recent study validates the Toronto Inflammatory Bowel Disease Global Endoscopic Reporting(TIGER)score offering a comprehensive assessment of inflammatory activity across diverse segments of the colon and rectum and a reliable index correlating strongly with UC Endoscopic Index of Severity and moderately with Mayo Endoscopic Subscore(MES).Despite recommendation,certain aspects warrant further *** calprotectin,an intermediate target,correlates with TIGER and should be *** TIGER scores defining endoscopic remission and response,evaluating agreement with histological activity,and assessing inter-endoscopist agreement for TIGER require *** the correlation between TIGER and intestinal ultrasound,akin to MES,adds value.

关键词： Ulcerative colitis Sigmoidoscopy Colonoscopy Score index

Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

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Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： f.Momo TEMGOUA L.Akana NGUIMDO DNJOMO Environmental Energy Technologies Laboratory(EETL) Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon Department of Electrical and Electronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical modeling of the interaction between solar radiation and the Earth's atmosphere is formalized by the radiative transfer equation(RTE), whose resolution calls for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the development of the phase function and the intensity into a third-order series of Legendre polynomials. This new approach, which adds one more term in the expression of the intensity and the phase function, allows in the conditions of a plane parallel atmosphere a new mathematical formulation of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Delta function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work also determines the conversion function of the proposed New Method using the fundamental definition of two-stream approximation(f-TSA) developed in a previous work. Notably,New Method has generally better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angle μ 0, but tends to deviate from the Disort method with the zenith angle, especially for high values of optical thickness. In spite of this divergence in reflectance for high values of optical thickness, very strong correlation with the Disort method(R ≈ 1) was obtained for most cases of optical thickness in this study. An analysis of the Legendre polynomial series for simple functions shows that the high precision is due to the fact that the approximated functions ameliorate the accuracy when the order of approximation increases, although it has been proven that there is a limit order depending on the function from which the precision is lost. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method Legendre polynomial optical thickness moments of specific intensity conversion function transmittance reflectance

Population dynamics of the tropical oyster Magallana bilineata(Mollusca,Bivalvia,Ostreidae)in Mengkabong Bay,Tuaran,Malaysia

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Aquaculture and fisheries 2024年第2期9卷 295-305页

作者： Joanna w.Doinsing Julian Ransangan Politeknik Sandakan Sabah Education HubBatu 10Jalan Sungai BatangSandakanSabah90000Malaysia Borneo Marine Research Institute Universiti Malaysia SabahJalan UMSKota Kinabalu88400Malaysia

Knowledge about the population dynamics within a specific spatial area is vital for the effective planning and management of important fishery *** parameters,including the asymptotic length(L∞),growth coefficient(K),mortalities(Z,f,and M),recruitment pattern,exploitation level(E),and yield per recruit(Y’/R),of the tropical oyster Magallana bilineata in Mengkabong Bay,Tuaran,Malaysia were analyzed by using the fiSAT software,using on the monthly shell length-frequency data collected from April 2019 to March 2020.A total of 435 oysters with shell lengths ranging from 3.64 to 11.16 cm were *** water temperature,salinity,dissolved oxygen,hydrogen ion concentration(pH),and chlorophyll concentration were measured at 29.0-33.7◦C,26.68-35.74 psμ,3.18-6.99 mg/L,6.57-8.29 and 1.51-98.93μg/L,*** logarithmic relationship between the length and weight of Log w=1.9055 Log L+0.1049(R2=0.5431)with exponent b of 1.9055 for combined sexes showed a negative allometric growth(bwth,including the use of genetically selected seeds,selection of new farming sites and adoption of grow-out methods that favour high meat *** length(L∞)and growth coefficient(K)of the von Bertalanffy Growth formula(VBGf)for *** were estimated at 12.13 cm and 1.00 yr􀀀1,*** theoretical ages at length zero(t0)(0.0487)were estimated by substituting L∞and K in Pauly’s *** sizes attained by *** were 3.76,5.04,6.13,7.05,7.83,and 8.49 cm at the end of 2,4,6,8,10,and 12 months,*** calculated growth performance index(φ)for *** in Mengkabong Bay was 2.168,while the estimated lifespan was 3 *** recruitment pattern was observed year-round,with higher recruitment activities in September-October 2019 and January *** total mortality(Z)was analyzed using the length-converted

关键词： Crassostrea iredalei Length-weight relationship Growth parameters Recruitment Exploitation

formation of diffuse and spark discharges between two needle electrodes with the scattering of particles

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Plasma Science and Technology 2024年第9期26卷 32-39页

作者： Victor f TARASENKO Dmitry V BELOPLOTOV Alexei N PANCHENKO Dmitry A SOROKIN Institute of High Current Electronics Siberian BranchRussian Academy of SciencesTomsk 634055Russia National Research Tomsk State University Tomsk 634050Russia

The development of a nanosecond discharge in a pin-to-pin gap filled with air at atmospheric pressure has been studied with high temporal and spatial resolutions from a breakdown start to the spark *** and negative nanosecond voltage pulses with an amplitude of tens of kilovolts were ***-resolved images of the discharge development were taken with a fourchannel Intensified Charge Coupled Device(ICCD)*** minimum delay between the camera channels could be as short as≈0.1 *** made it possible to study the gap breakdown process with subnanosecond *** was observed that a wide-diameter streamer develops from the high-voltage pointed *** ionization processes near the grounded pin electrode started when the streamer crossed half of the *** bridging the gap by the streamer,a diffuse discharge was *** development of spark leaders from bright spots on the surface of the pointed electrodes was observed at the next *** was found that the rate of development of the spark leader is an order of magnitude lower than that of the wide-diameter *** thin luminous tracks were observed against the background of a discharge plasma *** has been established that the tracks are adjacent to brightly glowing spots on the electrodes and are associated with the flight of small particles.

关键词： needle electrodes short voltage pulses atmospheric air streamer breakdown diffuse and spark discharges scattering metal particles