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Macro and micro issues in turbulent mixing

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Science China(technological Sciences) 2013年第10期56卷 2355-2360页

作者： MELVIN j KAUFMAN R LIM H KAMAN t RAO P GLIMM j Department of Applied Mathematics and Statistics Stony Brook UniversityStony Brook NY 11794 USA

Numerical prediction of turbulent mixing can be divided into two subproblems: to predict the geometrical extent of a mixing region and to predict the mixing properties on an atomic or molecular scale, within the mixing region. the former goal suffices for some purposes, while important problems of chemical reactions(e.g. flames) and nuclear reactions depend critically on the second goal in addition to the first one. Here we review recent progress in establishing a conceptual reformulation of convergence, and we illustrate these concepts with a review of recent numerical studies addressing turbulence and mixing in the high Reynolds number limit. We review significant progress on the first goal, regarding the mixing region, and initial progress on the second goal, regarding atomic level mixing properties. New results concerning non-uniqueness of the infinite Reynolds number solutions and other consequences of a renormalization group point of view, to be published in detail elsewhere, are summarized *** notion of stochastic convergence(of probability measures and probability distribution functions) replaces traditional pointwise convergence. the primary benefit of this idea is its increased stability relative to the statistical "noise" which characterizes turbulent flow. Our results also show that this modification of convergence, with sufficient mesh refinement, may not be needed. However, in practice, mesh refinement is seldom sufficient and the stochastic convergence concepts have a *** to this circle of ideas is the observation that turbulent mixing, in the limit of high Reynolds number, appears to be non-unique. Not only have multiple solutions been observed(and published) for identical problems, but simple physics based arguments and more refined arguments based on the renormalization group come to the same *** of the non-uniqueness inherent in numerical models of high Reynolds number turbulence and mixing, we also include here numeri

关键词： stochastic convergence turbulent mixing renormalization group dynamic subgrid scale models

Formation of tiAlSi intermetallics during heating ti-A356 Al mixed powder compact at semisolid temperature

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journal of Materials Science & technology 2021年第35期94卷 247-263页

作者： M.Gao t.j.Chen Z.X.Zhang State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China

Due to the similarity in composition and crystal structure of some ti Al Si ternary intermetallics,it is quite difficult to accurately confirm their physic characteristics,and thus,to tailor microstructure to improve mechanical properties of metal materials related to the ti Al Si ***,the formation process of ti Al Si intermetallics was investigated during heating ti-A356 mixed powder compact at a A356 alloy semisolid temperature of 595℃.the results indicated that two kinds of intermetallics ofτ1(tetragonal,I41/amd)andτ2(orthorhombic,Cmcm)generated,and both the concentration and supply direction of ti atoms,which are related to local breakage of oxide films on neighboring ti and A356 alloy powders,determined the phase and morphology of the intermetallics.τ1 andτ2 crystals all had an intrinsic plate morphology,butτ2 crystals were thinner due to more anisotropic growth resulted from their high density of stacking faults(SFs).τ1 lamellar domains generated during growth ofτ2 crystals,which were accompanied by decrease in density of *** combined effect of size difference and internal energy difference betweenτ1 andτ2 crystals made largeτ1 crystals coarsen at the expense ofτ2 crystals in Ostwald ripening,leading them to finally evolve into an agglomerate of largeτ1 plates.

关键词： Intermetallics Stacking faults Growth Phase transformation

A simulation study of the e^+/e^- sensitivity of a low resistive phosphate glass electrode in a RPC using GEANt MC

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Chinese Physics C 2010年第3期34卷 359-362页

作者： M.jamil j.t.Rhee Y.j.jeon Institute for Advanced Physics Department of Physics Konkuk University Liquid Crystal Research Center Konkuk University

the resistivity of conventional glass is quite high and is unacceptable in a high rate environment. Low resistive glass-electrodes could be a solution for this problem. the present study reports the e^＋/e^- simulation results of an RPC detector made from low resistive phosphate glass electrodes. the detailed geometrical configuration of the content materials which are the essential components of the glass of the RPC detector have been created with the GEANt4 simulation code. two different types of particle sources, i.e. for e^＋/e^- , have been located on the detectors surface to evaluate the performance of the phosphate glass RPC. Both of the particles have been simulated as a function of their respective energies in the range of 0.1 MeV 1.0 GeV. the present simulation work has shown that the resistive electrode plays an important role for the particle production in the RPC configuration.

关键词： Monte Carlo simulation resistive plate chamber GEANt4 simulation

Ballistic model for the prediction of penetration depth and residual velocity in adobe:A new interpretation of the ballistic resistance of earthen masonry

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Defence technology（防务技术） 2018年第5期14卷 607-611页

作者： t.Li Piani j.Weerheijm L.j.Sluys tU Delft Stevinweg 12628 CNDelftThe Netherlands tNO PO Box 452280 AARijswijkThe Netherlands NLDA Faculty of Military Sciences1781 CADen HelderThe Netherlands

In this paper, a new one-dimensional phenomenological model is developed for the assessment of the ballistic performance of Adobe. Adobe is a masonry largely spread in areas of the world involved in military operations. Addressing fundamental ballistic parameters such as residual velocity or penetration depth for this building technology is necessary. the model follows the hypotheses for the ballistic response of concrete targets to high velocity impacts, provided with a dominant contribution of shear friction typical of soils. the hypotheses at the basis of the model are consistent with all experimental evidence collected by authors on Adobe. Adobe brick and mortar belong to the material class of concrete,whereas the overall mechanical parameters are determined by the internal soil mixture, including the percentage of fibre reinforcement. Despite its relative simplicity, the model is capable of well predicting ballistic test results currently available in literature for Adobe, including the data of an experimental campaign recently performed by the authors on real Adobe walls in the field.

关键词： Impact Penetration Depth Residual velocity Adobe Wall Brick Mortar Ballistic

Novel insight into dry sliding behavior of Cu-Pb-Sn in-situ composite with secondary phase in different morphology

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journal of Materials Science & technology 2020年第5期40卷 158-167页

作者： B.W.Dong S.H.Wang Z.Z.Dong j.C.jie t.M.Wang t.j.Li School of Material Science and Engineering Dalian University of TechnologyDalian 116024China

the Cu-24 Pb-x Sn(wt%)(x=0,2,4,6)alloys with Pb-rich second-phase particles(SPPs)in different shapes show obviously differently mechanical and self-lubricating *** influence of the SPPs’shape difference on the alloys’mechanical and self-lubricating properties was ***-24 Pb alloy with continuously netty SPPs shows much more intensive stick-slip phenomenon during dry sliding than the other three alloys with independently rodlike *** is mainly due to insufficient lubrication resulted by the netty SPPs’splitting *** the SPPs transforming from netty to rodlike shape under the addition of Sn,the stick-slip phenomenon was notably weakened,which was proven to be related to the higher self-lubricating property of alloys with rodlike ***,the simultaneous increase of ductility and tensile strength was observed in the Cu-24 Pb-x Sn alloys with increasing Sn content,which is because the netty SPPs’splitting behavior will be weakened with them replaced by the rodlike SPPs.

关键词： Second-phase particles Netty shape Rodlike shape Stick-slip Mechanical property Self-lubricating property

Improving QoS Using Mobility-Based Optimized Multipath Routing Protocol in MANEt

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Computer Systems Science & Engineering 2023年第7期46卷 1169-1181页

作者： S.j.Sangeetha t.Rajendran Department of Computer Science Periyar UniversitySalem636011India PG and Research Department of Computer Science Government Arts and Science CollegeKangeyam638108India

Mobile Ad-hoc Networks(MANEts)connect numerous nodes to communicate data from the sender node to the target *** to the lack of an infrastructure network,mobile nodes communicate through wireless without an access *** does not have a centralized controller and has a dynamic network topology,which increases link failure and energy consumption resulting in excessive path delay,loss of Quality of service(QoS),and reduced throughput during data *** is a significant problem when the QoS of the link carrying the data is *** is one of the vital challenges of MANEt due to the very dynamic and distributed nature of *** article introduces a Mobility-Based Optimized Multipath Routing Protocol(MBOMRP)and an Efficient Reliable Link-State transmission(ERLSt)algorithm to overcome these *** proposed Mobility-Based Optimized Multipath Routing Protocol(MBOMRP)is utilized for route discovery and maintenance to efficiently avoid traffic and sleeping *** algorithm is used for efficient data transmission to increase QoS measurement parameters like throughput,Packet Delivery Ratio(PDR),and minimize the latency *** proposed MBOMRP-ERLSt algorithm improves data communication network lifetime,avoids link failures,and provides efficient results compared with previous algorithms.

关键词： MANEt QoS link failure improve data communication avoid traffic network lifetime MBOMRP-ERLSt

Metastable noble gas atoms in strong-field ionization experiments

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High Power Laser Science and Engineering 2016年第3期4卷 74-100页

作者： j.E.Calvert A.j.Palmer I.V.Litvinyuk R.t.Sang Australian Attosecond Science Facility Center for Quantum Dynamics School of Natural Sciences Griffith University

the interactions of strong-field few-cycle laser pulses with metastable states of noble gas atoms are examined. Metastable noble gas atoms offer a combination of low ionization potential and a relatively simple atomic structure, making them excellent targets for examining ionization dynamics in varying experimental conditions. A review of the current work performed on metastable noble gas atoms is presented.

关键词： COLtRIMS electron holography high power lasers ionization regime metastable atoms spin polarized targets

PHOtOCAtALYtIC PERFORMANCE OF PLASMA SPRAYED tiO_2-ZnFe_2O_4 COAtINGS

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 363-368页

作者： Y.Zeng j.t.Liu W.j.Qian j.H.Gao ShanghaiInstituteofCeramics TheChineseAcademyofSciencesShanghai200050China

A novel tiO2-ZnFe2O4 coating is prepared by plasma spraying. the effects of spra ying parameters and the composition of powders on the microstructure, surface mo rphology and photo-absorption of plasma sprayed coatings are studied. the photoc atalytic efficiency of the as-sprayed coatings is evaluated through the photo mi neralization of methylene blue. It was found that tiO2 coatings can decompose me thylene blue under the illumination of ultraviolet rays, and the degrading effic iency is improved with an increase in the content of FetiO3 in the coatings. How ever, the presence of large amount of ZnFe2O4 compound will substantially lower the photocatalytic efficiency of the tiO2-ZnFe2O4 coatings for the unfavorable p hoto-excited electron-hole transfer process.

关键词： plasma spraying photocatalytic activity tiO2 ZnFe2O4

Investigation of Single and Multiple Mutations Prediction Using Binary Classification Approach

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Intelligent Automation & Soft Computing 2023年第4期36卷 1189-1203页

作者： t.Edwin Ponraj j.Charles Department of Computer Applications Noorul Islam Centre for Higher EducationKumaracoil629180India Department of Software Engineering Noorul Islam Centre for Higher EducationKumaracoil629180India

the mutation is a critical element in determining the proteins’stability,becoming a core element in portraying the effects of a drug in the pharmaceutical *** wet laboratory tests to provide a better perspective on protein mutations is expensive and time-intensive since there are so many potential muta-tions,computational approaches that can reliably anticipate the consequences of amino acid mutations are *** work presents a robust methodology to analyze and identify the effects of mutation on a single protein ***,the context in a collection of words is determined using a knowledge graph for feature selection *** proposed prediction is based on an easier and sim-pler logistic regression inferred binary classiﬁcation *** approach can able to obtain a classiﬁcation accuracy(AUC)Area Under the Curve of 87%when randomly validated against experimental energy ***,for each cross-fold validation,the precision,recall,and F-Score are *** results support the validity of our strategy since it performs the vast majority of prior studies in this domain.

关键词： Proteins data science mutation analysis random forest neighbor proteins single and double mutations