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DEM prediction of industrial and geophysical particle flows

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Particuology 2010年第2期8卷 106-118页

作者： Paul w. Cleary CSIRO Mathematical and Information Sciences Private Bag 33 Clayton South 3169 Australia

Simulation of industrial particle flows using DEM （Discrete Element Method） offers the opportunity for better understanding of the flow dynamics by the inclusion of particle scale physics that often determine the nature of these flows. Increased understanding from the models can lead to improvements in equip- ment design and operation, potentially leading to large increases in equipment and process efficiency, throughput and]or product quality. Industrial applications are typically large and involve complex par- ticulate behaviour in complex geometries. This paper explores the critical influence of particle shape on granular system behaviour and then discusses examples of DEM applied to several large industrial problems. 2009 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. All rights reserved.

关键词： DEMGranular flowLandslideMillScreenMixing

A PERSONAL MEMOIR OF wEIMIN ZHENG-“A MAN FOR ALL SEASONS”

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Journal of Systems Science and Systems Engineering 2013年第4期22卷 499-504页

作者： Keith w.HIPEL Department of Systems Design Engineering University of Waterloo

In 1951 Professor weimin Zheng returned to the People＇s Republic of China from the United Kingdom to assist in building his country into a modern nation. Rather than pursue a doctoral degree at the California Institute of Technology, or Caltech as it is popularly called, Professor Zheng, unselfishly and patriotically, decided that he would devote his many talents to providing a first-class education to Chinese students within a strong university system. In particular,

关键词： A MAN FOR ALL SEASONS A PERSONAL MEMOIR OF wEIMIN ZHENG

An Introduction to Advanced Hot-Formed Steel for Automobile

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Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 373-382页

作者： w.J.Liu Research Academy Northeastern University

A recently developed advanced hot-formed （AHF） steel for automobile is introduced and three physical metallurgy concepts based on which the AHF steel was designed are reviewed, they are dynamic carbon partitioning （DCP）, flash copper precipitation and bake toughening. AHF steel is an upgrade of the existing hot-formed steel especially suitable for making components with superior crashworthiness; it can be processed by regular hot stamping equipment and process. A kinetics model for DCP is expressed in detail, which can be used to calculate the volume fraction of retained austenite based on four materials and processing parameters. The flash copper precipitation used as an additional strengthening mechanism for AHF steel is also discussed and its ultrafast kinetics can be attributed to the enhancement of quenched-in vacancies on copper diffusion. Also, the bake toughening of AHF steel is addressed; the mechanism of which may be related to the elimination of the less stable block-like retained austenite.

关键词： Advanced hot-formed (AHF) steel Dynamic carbon partitioning Flash copper precipitation Bake toughening Hot stamping

SYNTHESIS OF AN EPOXY-TERMINATED HYPERBRANCHED AROMATIC POLYESTER

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Chinese Journal of Polymer Science 2002年第6期20卷 585-590页

作者： w.J.Feast IRC in Polymer Science and Technology Durham University South Road Durham DH1 3LE UK

An epoxy-terminated hyperbranched aromatic polyester (P3) was synthesized from a hyperbranched aromatic polyester containing carboxylic acid end groups (P1), which was derived from the condensation polymerization of the AB(2) monomer, 5-acetoxyisophthalic acid. Polymer P1 was converted into the polymeric acid chloride by reaction with thionyl chloride. The acid chloride was reacted with ethanol and glycidol to form a poly(ethyl ester) (P2) and an epoxy terminated material (P3), respectively. The reaction conditions in each step of these processes had to be controlled very carefully to avoid unwanted cross-linking reactions. The characterization of products and intermediates, including molecular weight distributions and thermal properties, are reported.

关键词： hyperbranched polymer hyperbranched aromatic polyester epoxy-terminated hyperbranched aromatic polyester

Hyperspectral imaging and pulse characterization

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Light(Science & Applications) 2022年第10期11卷 2258-2259页

作者： Spencer w.Jolly Service Opera-Photonique Universitélibre de Bruxelles(ULB)BrusselsBelgium

An advanced method for hyperspectral imaging was combined with phase retrieval and standard pulse characterization techniques to characterize ultrashort laser pulses and ultrashort processes to a new level of precisio... 详细信息

关键词： pulse ultrashort characterization

Higher-Level Hardware Synthesis of the KASUMI Algorithm

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Journal of Computer Science & Technology 2007年第1期22卷 60-70页

作者： Issam w. Damaj Electrical and Computer Engineering Department Dhofar University P.O. Box 2509 Salalah 211 Oman

Programmable Logic Devices （PLDs） continue to grow in size and currently contain several millions of gates. At the same time, research effort is going into higher-level hardware synthesis methodologies for reconfigurable computing that can exploit PLD technology. In this paper, we explore the effectiveness and extend one such formal methodology in the design of massively parallel algorithms. we take a step-wise refinement approach to the development of correct reconfigurable hardware circuits from formal specifications. A functional programming notation is used for specifying algorithms and for reasoning about them. The specifications are realised through the use of a combination of function decomposition strategies, data refinement techniques, and off-the-shelf refinements based upon higher-order functions. The off-the-shelf refinements are inspired by the operators of Communicating Sequential Processes （CSP） and map easily to programs in Handel-C （a hardware description language）. The Handel-C descriptions are directly compiled into reconfigurable hardware. The practical realisation of this methodology is evidenced by a case studying the third generation mobile communication security algorithms. The investigated algorithm is the KASUMI block cipher. In this paper, we obtain several hardware implementations with different performance characteristics by applying different refinements to the algorithm. The developed designs are compiled and tested under Celoxica＇s RC-1000 reconfigurable computer with its 2 million gates Virtex-E FPGA. Performance analysis and evaluation of these implementations are included.

关键词： data encryption formal models gate array methodology parallel algorithms

State of the art of friction modelling at interfaces subjected to elastohydrodynamic lubrication(EHL)

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Friction 2021年第2期9卷 207-227页

作者： Zhuming BI Donald w.MUELLER Chris w.J.ZHANG Civil and Mechanical Engineering Purdue University Fort WayneIN 46805USA Department of Mechanical Engineering University of SaskatchewanSaskatoon SK S7N 5A9Canada

Elastohydrodynamic lubrication(EHL)is a type of fluid-film lubrication where hydrodynamic behaviors at contact surfaces are affected by both elastic deformation of surfaces and lubricant *** of contact interfaces under EHL is challenging due to high nonlinearity,complexity,and the multi-disciplinary *** paper aims to understand the state of the art of computational modelling of EHL by(1)examining the literature on modeling of contact surfaces under boundary and mixed lubricated conditions,(2)emphasizing the methods on the friction prediction occurring to contact surfaces,and(3)exploring the feasibility of using commercially available software tools(especially,Simulia/Abaqus)to predict the friction and wear at contact surfaces of objects with relative reciprocating motions.

关键词： elastohydrodynamic lubrication(EHL) lubricant rheology finite element analysis(FEA) friction prediction Simulia/Abaqus surface roughness coefficient of friction(CoF)

Sintering effect on electrical properties and pulse aging behavior of(V_2O_5-Mn_3O_4-Er_2O_3 )-doped zinc oxide varistor ceramics

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Journal of Rare Earths 2014年第1期32卷 29-36页

作者： Choon-w.Nahm Semiconductor Ceramics Laboratory Department of Electrical Engineering Dongeui University

The effect of sintering temperature on microstructure, electrical properties, and pulse aging behavior of （V2O5-Mn3O4-Er2O3）-doped zinc oxide varistor ceramics was systematically studied. when the sintering temperature increased, the average grain size increased from 6.1 to 8.7μm and the sintered density decreased from 5.52 to 5.43 g/cm3. The breakdown field decreased from 3856 to 922 V/cm with an increase in the sintering temperature up to 900 °C, whereas a further increase to 2352 V/cm at 925 °C. The nonlinear coefficient increased pronouncedly from 4.6 to 30.0 with an increase in the sintering temperature. The varistor ceramics sintered at 850 °C exhibited the best clamping characteristics, with the clamp voltage ratio of the range of 2.22-2.88 for pulse current of 1-25 A. The varistor ceramics sintered at 925 °C exhibited the strongest stability, with %ΔE1 mA/cm2=-8.8% after applying the multi-pulse current of 25 A.

关键词： ceramics sintering electrical properties pulse aging behavior varistors rare earths

Comparison of Patent Foramen Ovale and Aortic Atherosclerosis in Patients with Cryptogenic Ischemic Stroke or Transient Ischemic Attack

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Comparison of Patent Foramen Ovale and Aortic Atherosclerosi...