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A multiphysics model for studying transient crevice corrosion of stainless steel

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Journal of Materials Science & Technology 2021年第1期60卷 186-196页

作者： Jiawei Ding Haitao Wang En-Hou Han CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China

The transient crevice corrosion behavior of 304 stainless steel in NaCl solution has been investigated by a multiphysics coupling model.The model considers local electrochemical reactions,transport of diffe rent species,and homogeneous reactions.The moving mesh method is used to obtain the geometrical change of the crevice wall with time due to corrosion.The level set method is employed to quantitatively describe the influence of the precipitation process on electrochemical reactions.The transient crevice corrosion morphology,potential and current distributions,and pH and chloride ion concentration distributions are obtained by simulation.The effect of crevice geometry factors on the corrosion process is also discussed.The simulation results are in good agreement with the experiments,showing that the model has high reliability.

关键词： Stainless steel Crevice corrosion Simulation Multiphysics transient behavior

Sigma-delta modulator modeling analysis and design

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Journal of Semiconductors 2010年第9期31卷 79-83页

作者：葛彬杰王新安张兴冯晓星汪清勤 Key Laboratory of Integrated Microsystem Science & Engineering Applications Shenzhen Graduate School of Peking University

This paper introduces a new method for SC sigma-delta modulator modeling.It studies the integrator＇s different equivalent circuits in the integrating and sampling phases.This model uses the OP-AMP input pair＇s tail current（I_0） and overdrive voltage（v_（on）） as variables.The modulator＇s static and dynamic errors are analyzed.A group of optimized I0 and von for maximum SNR and power x area ratio can be obtained through this model.As examples, a MASH21 modulator for digital audio and a second order modulator for RFID baseband are implemented and tested, and they can achieve 91 dB and 72 dB respectively,which verifies the modeling and design criteria.

关键词： sigma-delta modeling transient behavior optimization

transient Analysis of Bandwidth Allocation Strategies in Broadband ISDN

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Wuhan University Journal of Natural Sciences 1996年第1期1卷 76-80页

作者： Yan Puliu Hou Jiechang (College of Electronic Information, Wuhan University, Wuhan 430072,China)

We study the transient behavior of B-ISDN bandwidth allocation strategies in tills paper. First, we present the united state transition equations and obtain the steady-state probability distribution vector by the matrixgeometric solution method. Second, we treat the problem in a uniform way that establishing the coupled differential equations describing the dynamic flow process of B-ISDN channel with the steady state probability as its initial condition and solve it numerically based on the fourth-order Runge-kutta procedure which allows a good balance between computing time and accuracy. Finally, experiment results and discussion are given to illustrate the effectes of the method presented in this paper and show that the idea and analysis way can be extended to all dynamic traffic controlling and management in B-ISDN systems.

关键词： B-ISDN transient behavior bandwidth allocation

一种非线性光电反馈光学双稳装置的瞬态特性研究

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东南大学学报(自然科学版) 1988年第6期 130-134页

作者：崔一平杨正名魏先任南京工学院电子工程系

自从Smith等人于1977年提出了“混合型”双稳装置以来,许多文献对此方案进行了改进。文献[8],[9]对线性反馈混合型光学双稳态的特性作了详细分析。此后李淳飞等人报道了一种非线性光电反馈的光学双稳装置的实验结果。随后他们又引入了... 详细信息

自从Smith等人于1977年提出了“混合型”双稳装置以来,许多文献对此方案进行了改进。文献[8],[9]对线性反馈混合型光学双稳态的特性作了详细分析。此后李淳飞等人报道了一种非线性光电反馈的光学双稳装置的实验结果。随后他们又引入了静态稳定度来分析双稳态的稳定性。本文对文献[10]所提出的非线性反馈双稳态的开关时间

关键词： nonlinear optoelectric feedback hybrid optical bistability transient behavior critical slowing down.