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Chinese Annals of Mathematics,Series B 2001年第1期22卷 93-114页

作者： l. lEVI g. VAllET Université de Pau & CNRS Laboratoire de Mathématiques Appliquées ERS 2055 I. P. R. A. Avenue de l'Université 64000 PAU France

This paper is devoted to the existence and the uniqueness of the entropy solution for a general scalar conservation law associated with a forced bilateral obstacle condition in a bounded domain of Rp, p>= 1. The method of penalization is used with a view to obtaining an existence result. However, the former only gives uniform l -estimates and so leads in fact to look for an Entropy Measure-Valued Solution, according to the specific properties of bounded sequences in l . The uniqueness of this EMVS is proved. Classically, it first ensures the existence of a bounded and measurable function U entropy solution and then the strong convergence in lq of approximate solutions to U.

关键词： Obstacle problem Measure-valued solution Scalar conservation law

Computational Investigation of the Substituent Effect on the Intramolecular Proton Transfer Reaction of 3-Hydroxytropolone

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Chinese Journal of Structural Chemistry 2014年第12期33卷 1757-1767页

作者： gül Vedat IsIN Dilara ozbakir Chemistry Department Faculty of ScienceCumhuriyet University 58140 SivasTurkey

The effects of substituent type and position on the proton transfer reaction of 3-hydroxytropolone(3-OHTRN) have been investigated theoretically by using density functional theory at the level of B3lYP/ 6-31+g** method. The influence of solvent on the proton transfer reactions of substituted 3-OHTRN has been examined using the self-consistent isodensity polarized continuum model(SCI-PCM) in water. As a result, while the proton transfer reaction is kinetically the easiest by substitution on position 3 of-NH2 group in the gas phase, it is kinetically the easiest by substitution on position 5 of the same group in water. In addition, these reactions are either kinetically or thermodynamically easier in the gas phase than that in water, except the reaction of structure with-NH2 group at position 6.

关键词： tropolone derivative 3-hydroxytropolone the proton transfer reaction density functional theory

新概念英语英汉对照流利英语附练习答案 3版

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Tracer advection in an idealised river bend with groynes

1988年

作者：（英）l.g.亚历山大陆英士韩益译

来源：汇雅图书（南通市图书馆... 评论

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Journal of Hydrodynamics 2018年第5期30卷 780-790页

作者： Mohammad Mahdi Jalali Alistair g.l.Borthwick Institute for Energy Systems School of Engineering The University of Edinburgh

This paper presents numerical simulations of particle advection in the bend of an open channel containing groynes, which is an idealised form of a shallow river bend in a wide river. The flow field is computed using a boundary-fitted solver of the non-orthogonal, curvilinear shallow water equations. The computational.g.id is generated by solving Poisson-type elliptic partial differential equations using an iterative multi-grid scheme for prescribed boundary coordinates. The shallow water equations are discretised with finite differences in space, and 4 t h order Runge-Kutta integration in time. Tracers introduced at specific initial locations have their trajectories computed using l.g.angian particle tracking. The numerical shallow flow model is verified by comparison to the analytical solution of fully developed flow in an open channel. The combined shallow flow and l.g.angian particle-tracking model is then used to simulate the advection of tracer particles in a rectangular channel containing a pair of parallel.g.oynes, and tracer particles in a curved open channel containing groynes, of dimensions roughly equivalent to a Danube River bend.

关键词： Shallow water equations tracer advection l.g.angian particle curvilinear coordinates system river bend groynes

Boundary discontinuous Fourier analysis of thick beams with clamped and simply supported edges via CUF

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Chinese Journal of Aeronautics 2017年第5期30卷 1708-1718页

作者： F.g.CANAlES J.l.MANTARI Faculty of Mechanical Engineering Universidad de Ingenieriay Tecnologia ( UTEC) Lima 15063 Peru Department of Mechanical Engineering University of New Mexieo Albuquerque 87131 USA

This paper presents an analytical solution for static analysis of thick rectangular beams with different boundary conditions. Carrera＇s Unified Formulation（CUF） is used in order to consider shear deformation theories of arbitrary order. The novelty of the present work is that a boundary discontinuous Fourier approach is used to consider clamped boundary conditions in the analytical solution, unlike Navier-type solutions which are restricted to simply supported *** equations are obtained by employing the principle of virtual work. The numerical accuracy of results is ascertained by studying the convergence of the solution and comparing the results to those of a 3D finite element solution. Beams subjected to bending due to a uniform pressure load and subjected to torsion due to opposite linear forces are considered. Overall, accurate results close to those of 3D finite element solutions are obtained, which can be used to validate finite element results or other approximate methods.

关键词： Analytical solution Beam Clamped Fourier Unified formulation

Tracer advection in a pair of adjacent side-wall cavities, and in a rectangular channel containing two groynes in series

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Journal of Hydrodynamics 2018年第4期30卷 564-572页

作者： Mohammad Mahdi Jalali Alistair g.l.Borthwick Institute for Energy Systems School of Engineering The University of Edinburgh

A model is presented of particle advection near groynes in an open channel. Open channel hydrodynamics is modelled using the shallow water equations, obtained as the depth-averaged form of Reynolds-averaged continuity and Navier-Stokes momentum equations. A l.g.angian particle-tracking model is used to predict trajectories of tracer particles advected by the flow field, with bilinear interpolation representing the continuous flow field. The particle-tracking model is verified for chaotic advection in an alternating flow field of a pair of blinking vortices. The combined shallow flow and l.g.angian particle-tracking model is applied to the simulation of tracer advection in flow past a pair of side-wall cavities separated by a groyne, and in an open rectangular channel containing a pair of parallel.g.oynes oriented normal to the channel wall. The study is potentially useful in understanding mixing processes in shallow flow fields near hydraulic structures in wide rivers.

关键词： Shallow water equations l.g.angian particle tracking chaotic advection blinking vortices side-wall cavities groynes

Vibrational behavior of isotropic plate structures in contact with a bounded fluid via unified formulation

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Chinese Journal of Aeronautics 2019年第4期32卷 921-937页

作者： F.g.CANAlES J.l.MANTARI Faculty of Mechanical Engineering Instituto de Investigación en Ingeniería Naval(IDIIN)Universidad Nacional de Ingenieria(UNI) Department of Mechanical Engineering University of New Mexico

This paper presents an analytical solution for free vibration analysis of thick rectangular isotropic plates coupled with a bounded fluid for various boundary conditions. In order to consider displacement theories of an arbitrary order, the Carrera Unified Formulation(CUF) is used. The eigenvalue problem is obtained by using the energy functional, considering plate and fluid kinetic energies as well as the potential energy of the plate. The Ritz method is used to evaluate the displacement variables, and the functions used in the Ritz series can be adjusted to consider any of the classical boundary conditions. The convergence of the solution is analyzed, and a validation of results considering open literature and 3D finite element software is performed. Parametric studies are carried out to obtain natural frequencies as a function of the side-to-thickness ratio, plate aspect ratio, fluid domain size, plate boundary conditions, and fluid-solid density ratio. Pressure and velocity in the fluid domain are evaluated in order to establish the consistency of the *** results for thick plates are obtained with a much lower computational cost compared to that of 3D finite element solutions.

关键词： Added mass Fluid-structure interaction Plate Ritz method Unified formulation Vibration

Active elastic metamaterials for subwavelength wave propagation control

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Acta Mechanica Sinica 2015年第3期31卷 349-363页

作者： Y.Y.Chen g.l.Huang Department of Mechanical and Aerospace Engineering University of Missouri

Recent research activities in elastic metamaterials demonstrate a significant potential for subwavelength wave propagation control owing to their interior locally resonant mechanism. The growing technol.g.cal developments in electro/magnetomechanical couplings of smart materials have introduced a controlling degree of freedom for passive elastic metamaterials. Active elastic metamaterials could allow for a fine control of material physical behavior and thereby induce new functional properties that cannot be produced by passive approaches. In this paper, two types of active elastic metamaterials with shunted piezoelectric materials and electrorheol.g.cal elastomers are proposed. Theoretical analyses and numerical validations of the active elastic metamaterials with detailed microstructures are pre- sented for designing adaptive applications in band gap structures and extraordinary waveguides. The active elastic metamaterial could provide a new design methodol.g. for adaptive wave filters, high signal-to-noise sensors, and structural health monitoring applications.

关键词： Active elastic metamaterials Subwavelengthwave control Adaptive metastructures Smart materials

Different effects of economic and structural performance indexes on model construction of structural topol.g. optimization

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Acta Mechanica Sinica 2015年第5期31卷 777-788页

作者： g.l.Yi Y.K.Sui Coll.g. of Mechanical Engineering and Applied Electronics Technol.g. Beijing University of Technology Department of Mechanical and Aerospace Engineering Seoul National University

The objective and constraint functions related to structural optimization designs are classified into economic and performance indexes in this *** influences of their different roles in model construction of structural topol.g. optimization are also ***,two structural topol.g. optimization models,optimizing a performance index under the limitation of an economic index,represented by the minimum compliance with a volume constraint（MCVC）model,and optimizing an economic index under the limitation of a performance index,represented by the minimum weight with a displacement constraint（MWDC）model,are *** on a comparison of numerical example results,the conclusions can be summarized as follows：（1）under the same external loading and displacement performance conditions,the results of the MWDC model are almost equal to those of the MCVC model;（2）the MWDC model overcomes the difficulties and shortcomings of the MCVC model;this makes the MWDC model more feasible in model construction;（3）constructing a model of minimizing an economic index under the limitations of performance indexes is better at meeting the needs of practical engineering problems and completely satisfies safety and economic requirements in mechanical engineering,which have remained unchanged since the early days of mechanical engineering.

关键词： Economic index Performance index Structural topol.g. optimization models MCVC model MWDC model Safety and economy

Beneficiation of the gold bearing ore by gravity and flotation

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 106-110页

作者： Alim gül Olga Kangal Ayhan A. Sirkeci güven nal Mineral Processing Engineering Department Istanbul Faculty of Mines Technical University Istanbul 34469 Turkey

gold concentration usually consists of gravity separation, flotation, cyanidation, or the combination of these processes. The choice among these processes depends on the mineral.g.cal characterization and gold content of the ore. Recently, the recovery of gold using gravity methods has gained attention because of low cost and environmentally friendly operations. In this study, gold pre-concentrates were produced by the stepwise gravity separation and flotation techniques. The Knelson concentrator and conventional flotation were employed for the recovery of gold. gold bearing ore samples were taken from gümüshane Region, northern east part of Turkey. As a result of stepwise Knelson concentration experiments, a gold concentrate assaying around 620 g/t is produced with 41.4wt% recovery. On the other hand, a gold concentrate about 82 g/t is obtained with 89.9wt% recovery from a gold ore assaying 6 g/t Au by direct flotation.

关键词： gold ore treatment beneficiation gold gravity separation flotation