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RHEOLOGICAL CHARACTERISTICS OF Al-6.5WT.%Si SEMISOLID METAL SLURRIES

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RHEOLOGICAL CHARACTERISTICS OF Al-6.5WT.%Si SEMISOLID METAL ...

第二届半固态金属加工技术研讨会

作者： j.y.chen L.P.ju Z.Fan Department of Physics Shenyang Normal University Shenyang 110034 P R China International Center for Materials Physics Chinese Academy of Sciences Shenyang 110016 P R China Dept of Mech. Eng. Brunei University Uxbridge Middlesex UB8 3PH UK

In this paper, the rheological model developed by present authors is applied to study the steady state and transient state behaviour of Al-6.5wt.%Si semi-solid metal (SSM) slurries. Application of the model has revealed a number of microstructural and rheological characteristics of SSM slurries. The theoretical analysis shows that there is a strong coupling between the microstructure and the steady state viscosity. It is shown that steady state viscosity of a SSM slurry decreases with increasing shear rate and approaches an asymptotic viscosity. This theoretical prediction is in good agreement with experimental results in the literature. Concerning time dependent properties, it is demonstrated that, irrespective of the flow conditions, the apparent viscosity of a SSM slurry with a specified solid fraction is exclusively determined by its structure, while the effect of shear rate and shearing time is reflected by their effect on slurry structure. The present model also indicates that the deagglomeration kinetics is about two orders of magnitude faster than the agglomeration kinetics for Al-6.5wt.%Si. The model has also been successfully applied to predict the hysteresis loops under various cyclic deformation conditions.

关键词： Rheology modeling pseudoplastisity thixotropy Al-alloy

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亚微米窄沟NMOS的增强辐照效应

微电子学 1984年第5期 54-57页

作者： j.y.chen 宁振球休斯飞机公司

我们已经观察了窄沟NMOS晶体管的增强辐射灵敏度。辐射导致的阈值漂移随沟道宽度在4μm以下减少而迅速增加。例如,同是4.5μm沟道长度,0.8μm宽FET器件的辐射灵敏度是5μm宽器件的两倍。这种几何图形依赖性可由2维电势计算来定量解释。... 详细信息

我们已经观察了窄沟NMOS晶体管的增强辐射灵敏度。辐射导致的阈值漂移随沟道宽度在4μm以下减少而迅速增加。例如,同是4.5μm沟道长度,0.8μm宽FET器件的辐射灵敏度是5μm宽器件的两倍。这种几何图形依赖性可由2维电势计算来定量解释。这些计算表明,辐射以后边缘场对阀值电压的影响减弱,这对窄沟器件来说就导致较大的阀值移动。

关键词：窄沟器件晶体管电压半导体三极管 NMOS 沟道长度氧化层电荷阈值电压漂移场氧化层亚微米

THE SyNERGISTIC INHIBITION STUDIES OF SEVERAL AMINES AND CHLORIDE ION ON IRON IN THE ACIDIC PERCHLORIDE SOLUTIONS

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Acta Metallurgica Sinica(English Letters) 1999年第5期12卷 952-957页

作者： j.H.Dong 1) ,j.y.chen 2,3) and. C.N.Cao 1) 1) State Key Laboratory for Corrosion and Protection of Metals, Institute of Corrosion and Protection of Metals, The Chinese Academy of Sciences, Shenyang 110015, China 2) The International Center

The effect of chloride ion on the corrosion inhibition of iron caused by dencylamine(DA), dipentylamine(DDA) and dodecylamine(DPA) has been investigated by measuring the inhibitory coefficients for the anodic and cathodic processes at corrosion potential. It has been shown that the major synergistic inhibition effects between amines and chloride ions occur in the cathodic process, very weak in the anodic process. The anodic inhibition mechanism follows the competing adsorptive model, while the cathodic inhibition mechanism follows the cooperative adsorptive model.

关键词： synergistic inhibition organic amine chloride ion

Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO_(2)thin films

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X chen M M chen y Liu D W Cao G j chen Department of Microelectronics Jiangsu UniversityZhenjiang 212013China Department of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–Hong Kong–Macao joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CMOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)

Rescattering of stimulated Raman side scattering in nonuniform plasmas

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Matter and Radiation at Extremes 2024年第5期9卷 68-76页

作者： S.Tan Q.Wang y.chen W.B.yao C.Z.Xiao j.F.Myatt School of Physics and Electronics Hunan UniversityChangsha 410082China Institute of Applied Physics and Computational Mathematics Beijing 100094China School of Electrical and Information Engineering Anhui University of Science and TechnologyHuainanAnhui 232001China Department of Electrical and Computer Engineering University of Alberta9211116 St.NWEdmontonAlberta T6G 1H9Canada

Rescattering of stimulated Raman side scattering(SRSS)is observed for the first time via two-dimensional(2D)particle-in-cell(PIC)*** construct a theoretical model for the rescattering process,which can predict the region of occurrence of mth-order SRSS and estimate its *** rescattering process is identified by the 2D PIC simulations under typical conditions of a direct-drive inertial confinement fusion *** electrons produced by second-order SRSS propagate nearly perpendicular to the density gradient and gain nearly the same energy as in first-order SRSS,but there is no cascade acceleration to produce superhot *** studies for a wide range of ignition conditions show that SRSS and associated rescatterings are robust and important processes in inertial confinement fusion.

关键词： nonuniform acceleration scattering

Exponentially Convergent Multiscale Finite Element Method

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Communications on Applied Mathematics and Computation 2024年第2期6卷 862-878页

作者： yifan chen Thomas y.Hou yixuan Wang Applied and Computational Mathematics CaltechPasadena 91106USA

We provide a concise review of the exponentially convergent multiscale finite element method(ExpMsFEM)for efficient model reduction of PDEs in heterogeneous media without scale separation and in high-frequency wave *** ExpMsFEM is built on the non-overlapped domain decomposition in the classical MsFEM while enriching the approximation space systematically to achieve a nearly exponential convergence rate regarding the number of basis *** most generalizations of the MsFEM in the literature,the ExpMsFEM does not rely on any partition of unity *** general,it is necessary to use function representations dependent on the right-hand side to break the algebraic Kolmogorov n-width barrier to achieve exponential ***,there are online and offline parts in the function representation provided by the *** online part depends on the right-hand side locally and can be computed in parallel *** offline part contains basis functions that are used in the Galerkin method to assemble the stiffness matrix;they are all independent of the right-hand side,so the stiffness matrix can be used repeatedly in multi-query scenarios.

关键词： Multiscale method Exponential convergence Helmholtz's equation Domain decomposition Nonlinear model reduction

Multi-population particle swarm optimization algorithm for automatic design of steel frames

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 89-103页

作者： Wenchen SHAN jiepeng LIU yao DING y.Frank chen junwen ZHOU Institute of Smart City and Intelligent Transportation Southwest Jiaotong UniversityChengdu 610000China School of Civil Engineering Chongqing UniversityChongqing 400045China Department of Civil Engineering the Pennsylvania State UniversityMiddletownPA 17057USA

Steel structures are widely used;however,their traditional design method is a trial-and-error procedure which is neither efficient nor cost ***,a multi-population particle swarm optimization(MPPSO)algorithm is developed to optimize the weight of steel frames according to standard design *** are made to improve the algorithm performances including the constraint-based strategy,piecewise mean learning strategy and multi-population cooperative *** proposed method is tested against the representative frame taken from American standards and against other steel frames matching Chinese design *** related parameter influences on optimization results are *** the representative frame,MPPSO can achieve greater efficiency through reduction of the number of analyses by more than 65% and can obtain frame with the weight for at least 2.4%lighter.A similar trend can also be observed in cases subjected to Chinese design *** addition,a migration interval of 1 and the number of populations as 5 are recommended to obtain better MPPSO *** purpose of the study is to propose a method with high efficiency and robustness that is not confined to structural scales and design *** aims to provide a reference for automatic structural optimization design problems even with dimensional *** proposed method can be easily generalized to the optimization problem of other structural systems.

关键词： steel frame multi-population particle swarm optimization automatic structural optimization design

Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/CdS heterojunction with photothermal effect for efficient photocatalytic hydrogen production

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journal of Materials Science & Technology 2024年第4期171卷 1-9页

作者： T.y.Huang Z.yang S.y.yang Z.H.Dai y.j.Liu j.H.Liao G.y.Zhong Z.j.Xie y.P.Fang S.S.Zhang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China School of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/CdS heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)CdS nanosheets on 2D MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous *** unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of *** irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of CdS *** study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure Heterostructure Photothermal effect Photocatalyst Hydrogen evolution

Tailored architecture of composite electrolyte for all-solid-state sodium batteries with superior rate performance and cycle life

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Nano Research 2024年第5期17卷 4171-4180页

作者： Xiang Guan Zhenhua jian Xingan Liao Wenchao Liao yanfei Huang Dazhu chen Robert K.y.Li chen Liu Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518055China Department of Materials Science and Engineering City University of Hong KongHong KongChina

Seeking for composite electrolytes reinforced all-solid-state sodium ion batteries with superior long lifespan and rate performance remains a great ***,a unique strategy to tailor the architecture of composite electrolyte via inserting polymer chains into a small quantity of sulfate sodium grafted C_(48)0H_(28)O_(32)Zr_(6)(UIOSNa)is *** intimate contact between polymer segments and UIOSNa with limited pore size facilitates the anion immobilization of sodium salts and reduction of polymer crystallinity,thereby providing rapid ion conduction and reducing the adverse effect caused by the immigration of *** tNa+grafting of-SO_(3)Na groups on fillers allows the free movement of more sodium ions to further improve and ionic ***,even with the low content of UIOSNa fillers,a high ionic conductivity of 6.62×10^(-4) S·cm^(-1) at 60℃ and a transference number of 0.67 for the special designed composite electrolyte are *** assembled all-solid-state sodium cell exhibits a remarkable rate performance for 500 cycles with 95.96%capacity retention at a high current rate of 4 *** corresponding pouch cell can stably work for 1000 cycles with 97.03%capacity retention at 1 C,which is superior to most of the reported composite electrolytes in the literature.

关键词： solid state sodium battery composite electrolyte rate performance cycle life