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Cellular automata modelling of grain coarsening during reheating——Ⅱ. Abnormal grain growth

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Journal of University of science and Technology Beijing 2005年第1期12卷 26-32页

作者： WanhuaYu E.J.palmiere s.p.banks JingtaoHan DepartmentofMaterialsEngineering UniversityofScienceandTechnologyBeijingBeijing100083China DepartmentofEngineeringMaterials UniversityofSheffieldS13JDSheffieldUK DepartmentofAutomaticControlandsystemsEngineering UniversityofSheffieldS13JDSheffieldUK

The 2-dimensional cellular automata (CA) simulation technique has been utilized to investigate the abnormal grain coarsening. The growth of abnormal grains is modelled under this assumption that different grains have different boundary energies and boundary mobilities. As temperature increases, some grains may first get rid of the particle pinning effect. Thus a high probability is obtained for atoms to jump over the boundary, so that they can consume other primary retained grains quickly. From the simulation, the characteristics of the abnormal grain coarsening under different conditions are demonstrated successfully. An experiment has also been carried out to reflect the abnormal grain coarsening on the microalloy steel. simulation results are quite close to the experimental evidence.

关键词： computer simulation grain growth microstructure reheating

CELLULAR AUTOMATA MODELLING OF GRAIN COARsENING DURING REHEATING AND VALIDATION WITH THE EXpERIMENTAL REsULTs

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Acta Metallurgica sinica(English Letters) 2005年第2期18卷 113-120页

作者： W.H.Yu E.J.palmiere s.p.banks J.T.Han schoolofMaterialsscienceandEngineering UniversityofScienceandTechnologyBeijingBeijing100083China DepartmentofEngineeringMaterials UniversityofSheffieldSheffieldS13JDUK DepartmentofAutomaticControlandsystemsEngineering UniversityofSheffieldSheffieldS13J-DUK

A novel 2D cellular automata (CA) model has been developed for description of normal grain coarsening and abnormal grain coarsening process. The program reflects the grain coarsening quite well even through the average grain size becomes very large. Follow results have been obtained: (a) The model reflect the normal grain growth kinetics gradually increase with probability and grain growth speed can be controlled. Based on this result, temperature can be coupled in the model. (b) Abnormal grain growth is modelled successfully. (c) Methodology has been put forward to find the relationship between the experiment results and modelling results. The experimental work on the grain coarsening has been carried out. Graphical output matched the realistic microstructure in every detail. Because many physical parameters can be taken into account in the CA programme, this CA model could not only qualitatively demonstrate the grain growth process, but also quantitatively predict and analyse the grain coarsening process.

关键词： computer simulation grain growth microstructure reheating

Robust Cross-Linked Na_(3)V_(2)(pO_(4))_(2)F_(3) Full sodium-Ion Batteries

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Energy & Environmental Materials 2024年第1期7卷 9-20页

作者： Jinqiang Gao Ye Tian Lianshan Ni Baowei Wang Kangyu Zou Yingchang Yang Ying Wang Craig E.banks Dou Zhang Kechao Zhou Huan Liu Wentao Deng Guoqiang Zou Hongshuai Hou Xiaobo Ji College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China College of Material and Chemical Engineering Tongren UniversityTongren 554300China Department of Chemistry The Chinese University of Hong KongShatinN.T.Hong Kong S.A.R.China Faculty of science and Engineering Manchester Metropolitan UniversityManchester UK state Key Laboratory of powder Metallurgy Central South UniversityChangsha 410083China school of Materials science and Engineering Hunan Provincial Key Lab of Advanced Materials for New Energy Storage and ConversionHunan University of Science and TechnologyXiangtan 411201China school of Materials and Engineering Zhengzhou UniversityZhengzhou 450001China

sodium-ion batteries(sIBs)have rapidly risen to the forefront of energy storage systems as a promising supplementary for Lithium-ion batteries(LIBs).Na_(3)V_(2)(pO_(4))_(2)F_(3)(NVpF)as a common cathode of sIBs,features the merits of high operating voltage,small volume change and favorable specific energy ***,it suffers from poor cycling stability and rate performance induced by its low intrinsic ***,we propose an ingenious strategy targeting superior sIBs through cross-linked NVpF with multi-dimensional nanocarbon frameworks composed of amorphous carbon and carbon nanotubes(NVpF@C@CNTs).This rational design ensures favorable particle size for shortened sodium ion transmission pathway as well as improved electronic transfer network,thus leading to enhanced charge transfer kinetics and superior cycling *** from this unique structure,significantly improved electrochemical properties are obtained,including high specific capacity(126.9 mAh g^(-1)at 1 C,1 C=128 mA g^(-1))and remarkably improved long-term cycling stability with 93.9%capacity retention after 1000 cycles at 20 *** energy density of 286.8 Wh kg^(-1)can be reached for full cells with hard carbon as anode(NVpF@C@CNTs//HC).Additionally,the electrochemical performance of the full cell at high temperature is also investigated(95.3 mAh g^(-1)after 100 cycles at 1 C at 50℃).such nanoscale dual-carbon networks engineering and thorough discussion of ion diffusion kinetics might make contributions to accelerating the process of phosphate cathodes in sIBs for large-scale energy storages.

关键词： dual-nanocarbon networks full sodium-ion battery ion transfer kinetics Na_(3)V_(2)(pO_(4))_(2)F_(3) NAsICON structure

Nonlinear optimal control of rotating flexible shaft in active magnetic bearings

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science China(Technological sciences) 2011年第5期54卷 1084-1094页

作者： G. s. TOMBUL s. p. banks Department of Automatic Control & systems Engineering The University of Sheffield

The optimal control of nonlinear systems has been studied for years by many researchers. However, the application of optimal control problem to nonlinear non-affine systems needs more attention. In this paper we propose an optimal control design technique for a class of nonlinear and control non-affine equations. The dynamic equations of a flexible shaft supported by a pair of active magnetic bearings (AMBs) are used as the nonlinear control non-affine equations. Mathematical model for the flexible beam is chosen to be the well known Timoshenko beam model, which takes rotary inertia and shear deformations into account, and it is assumed that the shaft is supported by two frictionless bearings at the ends. The effective control of such systems is extremely important for very high angular velocity shafts which are a feature of many modern machines. The control must be able to cope with unbalanced masses and hence be very robust. We shall approach the problem by discretising the Timoshenko beam model and using standard difference formulae to develop a finite-dimensional model of the system. Then we use a recently developed technique for controlling nonlinear systems by reducing the problem to a sequence of linear time-varying (LTV) systems. An optimal control designed for each approximating linear, time-varying system and recent results show that this method will converge uniformly on compact time intervals to the optimal solution.

关键词： approximation technique nonlinear optimal control timoshenko beam active magnetic bearings

Modelling of propagating shear Waves in Biotissue Employing an Internal Variable Approach to Dissipation

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Communications in Computational physics 2008年第3期3卷 603-640页

作者： H.T.banks Nicholas s.Luke Center for Research in scientific Computation North Carolina State UniversityRaleighNC 27695-8205USA.

The ability to reliably detect coronary artery disease based on the acousticnoises produced by a stenosis can provide a simple, non-invasive technique for *** research exploits the shear wave fields in body tissue to detect andanalyze coronary stenoses. The methods and ideas outlined in earlier efforts [6] includinga mathematical model utilizing an internal strain variable approximation tothe quasi-linear viscoelastic constitutive equation proposed by Fung in [19] is extendedhere. As an initial investigation, a homogeneous two-dimensional viscoelastic geometryis considered. Being uniform in θ, this geometry behaves as a one dimensionalmodel, and the results generated from it are compared to the one dimensional resultsfrom [6]. To allow for different assumptions on the elastic response, several variationsof the model are considered. A statistical significance test is employed to determine ifthe more complex models are significant improvements. After calibrating the modelwith a comparison to previous findings, more complicated geometries are *** involving a heterogeneous geometrywith a uniformring running throughthe original medium, a θ-dependent model which considers a rigid partial occlusionformed along the inner radius of the geometry, and a model which combines the ringand occlusion are presented.

关键词： Viscoelasticity partial differential equations shear waves biotissue.

A method to evaluate REE-HFsE mineralised provinces by value creation potential, and an example of application: Gardar REE-HFsE province, Greenland

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Geoscience Frontiers 2020年第6期11卷 2141-2156页

作者： Graham J.banks símun D.Olsen Antonio Gusak Geological survey of Denmark and Greenland Øster Voldgade 10DK-1350CopenhagenDenmark permanent Address:Route to Reserves Ulriksdalvej 13Valby2500CopenhagenDenmark University of Copenhagen Øster Voldgade 10DK-1350CopenhagenDenmark

The rare earth elements and high-field-strength elements(REE-HFsE)exploration sector conducts most evaluations at deposit and smaller *** is not evident how the sector performs a preceding exploration stage—rating and prioritising REE-HFsE mineralised provinces—to determine which provinces are prospective enough to warrant *** we present an objective,repeatable,low-cost method to screen any REE-HFsE province,as a foundation for district-scale investigations or asset *** is original for REE-HFsE screening,and adapted from regional scale copper,cobalt and petroleum exploration,and CO2 storage,screening *** is centred upon a mineralised province’s favourability for potential value creation,and to identify:(a)its main information gaps;(b)its weakest links;(c)its exploration maturity and remaining potential category;(d)how it compares against other REE-HFsE provinces;and(e)if further investigation is *** method incorporates geoscience,strategy,economic and socio-environmental factors in a way that is understandable and directly usable across stakeholder *** workflow is systematic,yet flexible enough to accommodate organisationspecific criteria,and usable for other *** provides the platform to build a global REE-HFsE province map and database consistently across national boundaries and *** for the extent of province exploration maturity and remaining mineral potential are *** illustrate the applicability of these methods using the Gardar REE-HFsE province(GRHp)of south *** conclude that it is a moderate size,frontier province that is currently of questionable favourability for value *** move GRHp into a positive favourability class,its current weak links need strengthening by research,government policy and industry stakeholders:evaluate the mineral system;integrate all information geospatially and place it in the public domain;help the region improve some communi

关键词： REE HFsE province screening Favourability Value

Absolute parameters of young stars:pU pup

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Research in Astronomy and Astrophysics 2021年第10期21卷 151-163页

作者： Ahmet Erdem Derya surgit Timothy s.banks Burcu Ozkardes Edwin Budding Canakkale Onsekiz Mart University Astrophysics Research Center and Ulupinar ObservatoryTR-17100CanakkaleTurkey Department of physics Faculty of Arts and SciencesCanakkale Onsekiz Mart UniversityTerzioglu KampusuTR-17100CanakkaleTurkey Department of space sciences and Technologies Faculty of Arts and SciencesCanakkale Onsekiz Mart UniversityTerzioglu KampusuTR-17100CanakkaleTurkey Data science Nielsen200 W JacksonChicagoIL 60606USA physics&Astronomy Harper College1200 W Algonquin RdPalatineIL 60067USA Visiting astronomer Mt.John ObservatoryUniversity of CanterburyPrivate Bag 4800Christchurch 8140NZ Carter Observatory Wellington 6012New Zealand school of Chemical&physical sciences Victoria University of WellingtonWellington 6012New Zealand Variable stars south RASNZPO Box 3181WellingtonNew Zealand

We present combined photometric and spectroscopic analyses of the southern binary star pU ***-resolution spectra of this system were taken at the University of Canterbury *** Observatory in the years 2008 and again in *** find the light contribution of the secondary component to be only 2%of the total light of the system in optical wavelengths,resulting in a single-lined spectroscopic *** TEss data revealed grazing eclipses within the light minima,though the tidal distortion,examined also from Hipparcos data,remains the predominating light curve *** model shows pU pup to have the more massive primary relatively close to filling its Roche *** pup is thus approaching the rare‘fast phase’of interactive(Case B)*** adopted absolute parameters are as follows:M_(1)=4.10(±0.20)M_(⊙),M_(2)=0.65(±0.05)M_(⊙),R_(1)=6.60(±0.30)R_(⊙),R_(2)=0.90(±0.10)R_(⊙);T_(1)=11500(±500)K,T_(2)=5000(±350)K;photometric distance=186(±20)pc,age=170(±20)*** less-massive secondary component is found to be significantly oversized and overluminous compared to standard main sequence *** discuss this discrepancy referring to heating from the reflection effect.

关键词： (stars:)binaries(including multiple):close stars:early-type stars:individual(pU pup) Galaxy:stellar content

On Exact Conservation for the Euler Equations with Complex Equations of state

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Communications in Computational physics 2010年第10期8卷 995-1015页

作者： J.W.banks Center for Applied scientific Computing Lawrence Livermore National LaboratoryLivermoreCA 94551USA

Conservative numerical methods are often used for simulations of fluid flows involving shocks and other jumps with the understanding that conservation guarantees reasonable treatment near *** is true in that convergent conservative approximations converge to weak solutions and thus have the correct shock ***,correct shock location results from any discretization whose violation of conservation approaches zero as the mesh is *** we investigate the case of the Euler equations for a single gas using the Jones-Wilkins-Lee(JWL)equation of *** show that a quasi-conservative method can lead to physically realistic solutions which are devoid of spurious pressure ***,we demonstrate that under certain conditions,a quasi-conservative method can exhibit higher rates of convergence near shocks than a strictly conservative counterpart of the same formal order.

关键词： Euler equations complex EOs JWL EOs Godunov methods

Endoscopic endonasal intraconal orbit surgery

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World Journal of Otorhinolaryngology-Head and Neck surgery 2020年第2期6卷 100-105页

作者： Catherine banks Qasim Husain Benjamin s.Bleier Massachusetts Eye and Ear Infirmary Department of OtolaryngologyHarvard Medical SchoolBostonMAUSA

Endoscopic endonasal orbital surgery is *** increasing knowledge,expertise,and technology,the historical limits of the endonasal endoscopic approach to the orbit have been *** review discusses the clinical presentation and etiology,and highlights the pertinent anatomy,and discusses the diagnostic workup and surgical approach to orbital tumors and post-operative *** role of the multidisciplinary team is not to be *** introduction of a classification system to ensure standardization of technical difficulty and outcome data will assist with international collaboration and further consolidate our attainment of knowledge in this developing field.

关键词： Endoscopic endonasal orbital surgery Intraconal space tumors Extraconal space tumors Orbital cavernous hemangioma