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Coarse Embedding into Uniformly Convex Banach Spaces

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Chinese Annals of mathematics,Series B 2014年第5期35卷 733-742页

作者： Qinggang ren College of Computer Science Chongqing University

In this paper, the author studies the coarse embedding into uniformly convex Banach spaces. The author proves that the property of coarse embedding into Banach spaces can be preserved under taking the union of the metric spaces under certain condi- tions. As an application, for a group G strongly relatively hyperbolic to a subgroup H, the author proves that B（n） = {g ∈ G／ │g│suЭe≤ n} admits a coarse embedding into a uniformly convex Banach space if H does.

关键词： Coarse embedding Uniformly convex Banach spaces Relative hyper-bolic groups

NUmERICAL STUDY OF THE NOTCH EFFECT ON THE CREEP BEHAVIOR AND LIFE OF NICKEL-BASE SINGLE CRYSTAL SUPERALLOYS

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Acta metallurgica Sinica(English Letters) 2004年第4期17卷 487-492页

作者： Q.m.Yu z.F.Yue Department of Engineering mechanics Northwestern Polytechnical University Xi'an 710072 ChinaDepartment of Engineering Mechanics Northwestern Polytechnical University Xi'an 710072 China

Numerical calculations of creep damage development and life behavior of circular notched specimens of nickel-base single crystal had been performed. The creep stress distributions depend on the specimen geometry. For a small notch radius, von mises stress has an especial distribution. The damage distribution is greatly influenced by the notch depth, notch radius as well as notch type. The creep crack initiation place is different for each notched specimen. The characteristics of notch strengthening and notch weakening depend on the notch radius and notch type. For the same notch type, the creep rupture lives decrease with the decreasing of notch radius. A creep life model has been presented for the multiaxial stress states based on the crystallographic slip system theory.

关键词： creep damage life model notched specimen nickel-base single crystal superalloys

Collaborative Supply Chain management: A Critical Redesigning Factor

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厦门大学学报（自然科学版） 2002年第S1期41卷 257-258页

作者： z m Udin Department of mechanical and medical Engineering

In improving the competitiveness of business organi sa tion in the 21st century, minimising cost and increasing productivity are no lon ger factors that could promise the success. The changes in customer trends whic h focusing more on product or service customising, high quality and short delive ry times are additional crucial factors that organisation should be aware of. T hese factors have direct relations on how the management could utilise the capab ility of its supply chain management (SCm). The importance of SCm in organisati on specifically to manufacturer is to play a vital role in managing the flow of material and information along the chain from suppliers to customers. In a trad itional way, SCm is mainly manage by the production department in organisation b ut with the advancement in information technology, resulted the changes in worki ng environment. One of the ways that could be implemented in decision making p rocess in order to improve the effectiveness and efficiency of the decision is t hrough collaborative environment. Due to this situation, there is a need to rede sign the existing SCm in order to optimise its capability and functionality in t he way to ensure the organisation competitiveness is sustainable. A minor or ma jor alignment to SCm business processes should be done in order to streamline th e flow of information, which could also affect the flow of materials. Factors s uch as SCm operational, structural and even its managerial are among the issues that are critical in redesigning its business process. Each of these factors has its own attributes such as lead-times, complexity, frequency and organisationa l setting that could lead in improving organisational competitiveness. In additi on, by identifying these factors, it would help the management to plan and desig n the collaborative SCm that would effectively correspond to the changes in busi ness and customer trends. The intention of the paper is to promote a list of fa ctors and attr

关键词： SCm A Critical Redesigning Factor Collaborative Supply Chain management

REAL-TImE FLOOD FORECASTING mODELING OF 1D UNSTEADY CHANNEL FLOW AND KALmAN FILTER

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Journal of Hydrodynamics 2001年第1期13卷 64-69页

作者： Li, z.J. Weng, m.H. Coll. of Water Res. and Environ. Hohai Univ. Nanjing 210024 China

The model of 1D unsteady channel flow combined with the Kalman filter for real-time channel flood forecasting was attempted. The suitable upstream and downstream boundary conditions were suggested. The system equation was given by the linearization of the finite difference equations of the mass conservation and momentum equations as well as the boundary conditions. In the Kalman filter updating model, because the number of measurement variable is less than that of state-space variables, the measurement error covariance matrix could be estimated in real time through the innovation sequence, and the system error covariance matrix needs to be estimated preliminarily. A real example of flood forecasting in the Huaihe River was given to explain how the method works. The results show that the model is reasonable and effective.

关键词： Channel flow Computer simulation Kalman filtering Unsteady flow

Axisymmetric Stagnation-Point Flow with a General Slip Boundary Condition over a Lubricated Surface

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Chinese Physics Letters 2012年第2期29卷 126-129页

作者： m.Sajid K.mahmood z.Abbas The Abdus Salam International Centre for Theoretical Physics Strada Costiera 1134014TriesteItaly Department of mathematics Riphah International UniversityIslamabad 44000Pakistan Department of mathematics The Islamia University of BahawalpurBahawalpurPakistan

We investigate the axisymmetric stagnation-point flow of a viscous fluid over a lubricated surface by imposing a generalized slip condition at the fluid-fluid *** power law non-Newtonian fluid is considered as a *** lubrication layer is thin and assumed to have a variable *** transformed nonlinear ordinary differential equation governing the flow is linearized using *** method of superposi-tion is adopted to convert the boundary value problem into an initial value problem and the solution is obtained numerically by using the fourth-order Runge-Kutta *** results are discussed to see the influence of pertinent *** limiting cases of Navier and no-slip boundary conditions are obtained as the special cases and found to be in excellent agreement with the existing results in the literature.

关键词： boundary ordinary assumed

Electron localization of H_2^+ in a dc electric field

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Chinese Physics B 2017年第1期26卷 170-175页

作者： z m Jia z N zeng W T Tang R X Li State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China Signal and Information Processing Jingchu University of Technology Jingmen 448000 China

A dc electric field is utilized to steer the electron motion after the molecular ion H2-＋ is excited by an ultrashort ultraviolet laser pulse. The numerical simulation shows that the electron localization distribution and the dissociation control ratio are dependent on the polarization direction and amplitude of the dc electric field. most electrons of the dissociation state move opposite to the dc electric field and stabilize at the dressed-up potential well, for the dressed-down well is occupied by the electrons of the 1 sσg state.

关键词： dissociation localization time dependent Schrdinger equation Coulomb potential ultraviolet laser pulse

microstructure and mechanical properties of hot extruded 6016 aluminum alloy/graphite composites

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Journal of materials Science & Technology 2018年第9期34卷 1580-1591页

作者： mohamed m.El-Sayed Seleman mohamed m.z.Ahmed Sabbah Ataya Department of metallurgical and materials Engineering Faculty of Petroleum and Mining Engineering Suez University 43518 Suez Egypt Suez and Sinai metallurgical and materials Research Center of Scientific Excellence (SSmmR-CSE) 43518 Suez Egypt The British University in Egypt Mechanical Engineering Deportment El-Sherouk City 11837 Cairo Egypt Department of mechanical Engineering College of Engineering AI Imam Mohammad Ibn Saud Islamic University Riyadh 11432 saudi Arabia

The incorporation of graphite particles into AA6016 aluminum alloy matrix to fabricate metal/ceramic composites is still a great challenge and various parameters should be considered. In this study, dense AA6016 aluminum alloy/（0-20 wt%） graphite composites have successfully been fabricated by powder metallurgy process. At first, the mixed aluminum and graphite powders were cold compacted at 200 mPa and then sintered at 500 ℃ for 1 h followed by hot extrusion at 450 ℃. The influence of ceramic phases（free graphite and in-situ formed carbides） on microstructure, physical and mechanical properties of the produced composites were finally investigated. The results show that the fabricated composites have a relative density of over 98%. SEm observations indicate that the graphite has a good dispersion in the alloy matrix even at high graphite content. Hardness of all the produced composites was higher than that of aluminum alloy matrix. No cracks were observed at strain less than 23% for all hot extruded *** strength, reduction in height, ultimate tensile stress, fracture stress, yield stress, and fracture strain of all Al/graphite composites were determined by high precision second order equations. Both compressive and ultimate tensile strengths have been correlated to microstructure constituents with focusing on the in-situ formed ceramic phases, silicon carbide（SiC） and aluminum carbide（Al4 C3）. The ductile fracture mode of the produced composites became less dominant with increasing free graphite content and in-situ formed carbides. Wear resistance of Al/graphite composites was increased with increasing graphite content. Aluminum/20 wt% graphite composite exhibited superior wear resistance over that of AA6016 aluminum alloy.

关键词： AA6016/graphite composites Hot extrusion In-situ carbides mechanical properties Wear resistance Fracture behavior

Surface Characterisation of Silicon Based mEmS

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Chemical Research in Chinese Universities 2004年第4期20卷 407-410页

作者： LI J. CUI z m. A. Baker The Surface Analysis Laboratory School of Engineering University of SurreyRutherford Appleton LaboratoryThe Surface Analysis Laboratory School of Engineering University of Surrey Guildford GU2 7XH UKChilton Didcot UKGuildford GU2 7XH UK

Polysilicon microelectromechanical systems(mEmS) are the subject of intensive researches. Surface chemistry and topography of a mEmS test structure fabricated at Sandia National Laboratory, USA, were studied by means of scanning electron microscopy(SEm), X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFm). XPS C_ 1sand Si_ 2pspectra from the polysilicon components, silicon nitride substrate and a reference silicon wafer were compared. The results confirm the presence of a self-assembled monolayer(SAm) on the mEmS surface. An island-like morphology was found on both polysilicon and silicon nitride surfaces of the mEmS. The islands take the form of caps, being up to 0.5 μm in diameter and 20 nm in height. It is concluded that the co-existence of columnar growth and equiaxed growth during the low pressure chemical vapor deposition(LPCVD) of these layers leads to the observed morphology and the islands are caps to the columnar structures.

关键词： microelectromechanical systems XPS Atomic force microscopy

One-Dimensional Anyon Lattice and slq（2） Algebra Realization

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Chinese Physics Letters 2005年第5期22卷 1207-1209页

作者： z.Bentalha m.Tahiri B.Liani TheoreticalPhysicsLaboratory TlemcenUniversityTlemcenAlgeria LaboratoiredePhysiqueThéorique Universitéd'Essenia31100OranAlgeria

We discuss the connection between anyons (Particles with fractionalstatistics) living on a one-dimensional lattice and sl(q)(2) algebra. We assign to each site-anyonfield, then we demand the anyonic fields to be noncommuting objects in agreement with theChern-Sinions picture of anyons. We show how the anyonic algebra can emerge from these noncommutingobjects. Starting from the emerged algebra we build the Sl(q)(2) algebra at q roots of unity.

关键词： Algebra