开关变换器的潜电路特性及其分析方法

在谐振开关电容变换器中已存在潜电路现象的基础上,系统地提出潜电路路径的图论分析方法,并从能量平衡的角度出发,得到潜电路的发生规律.由此总结出电力电子开关变换器潜电路的一般化分析方法,从而在开发与设计过程中开展安全诊断,及时发现潜电路,必要时加以消除或利用.实验结果证明了该分析方法的正确性.     

OrCAD电路性能分析方法在电路仿真实验中的应用

使用OrCAD／PSpice电路仿真软件的电路性能分析方法,能够定量分析元件参数与电路特性的关系,从而为电路仿真实验提供了有效途径。此文旨在通过具体的实验事例,阐述电路性能分析方法在电路仿真中的应用过程。     

从一个电路的多种解法谈电路的分析方法

通过对线性电阻电路基本分析方法的比较,阐明不同分析方法之间的区别与联系,其思路和方法对动态和稳态电路的分析依然适用。     

对悬浮元器件的类Y参数变换

本文针对现在集成电路集成度的提高和规模的加大,其电路分析所用的时间加长的难题提出了一种新的电路分析方法——类Y参数变换,并与现有的电路分析方法相比,可以减少一计算量,节约分析时间,缩短设计周期。     

一类振荡电路的微分方程分析法及其改进电路

通过微分方程稳定性的分析方法对单元振荡电路Colpitts振荡器进行了研究，得出电路的起振、稳定与其电路参数的密切关系，并对振荡规律进行了解释。根据振荡频率的表达式，给出一种改进后的电路，提出了振荡电路的另一类分析方法。     

电路本质安全性能计算机分析方法

直流低压本质安全电路在IEC火花试验装置上进行爆炸检测时会产生电弧放电。如果将火花试验装置的电极在闭合或断开时的放电电弧看作一个非线性电阻，则可以实现电路本质安全性能的计算机辅助分析方法。介绍了电路本质安全性能计算机分析方法的评价原则；给出了3种不同性质电路(电阻、电感和电容)的电弧放电数学模型；介绍了计算机辅助分析方法的步骤以及电路本质安全性能分析的特殊问题：最后给出计算机分析软件的流程图和结果样例。为设计人员预估电路本质安全性能提供一个方便的方法。     

运算放大电路教学方法研究

运算放大电路是模拟电子技术的核心电路之一,经典教材中分析该电路功能特性时采用线性电路多种分析方法,在教学中发现学生难以接受。该文明确提出利用元件约束VCR和结构约束KCL结合理想运放虚短虚断特点分析电路,经过课堂实践,发现该分析方法有助于学生对运算放大电路的理解,提升了学生对该知识点的掌握,有助于模拟电子技术课程的学习。     

计算电磁学中的场路协同仿真方法综述

随着集成电路的集成度和脉冲信号速度的提高,电路中的波效应越来越明显,单纯使用电路分析方法已不能满足精度要求,这种情况下必须对原问题分而治之.采用3维电磁场全波方法对封装与互连结构进行分析,采用电路分析方法对电路元件或电路模块进行分析,最后将二者耦合起来实现场路协同仿真.论文首先对计算电磁学中的场路协同仿真问题进行分类,然后分别介绍各类场路协同仿真的国内外研究现状,最后探讨场路协同仿真的未来研究方向.     

LCR电路暂态方程中各项正负号的确定

本文从回路电压方程出发,首先分析LR和RC电路的暂态方程,在这一基础上,再来分析LCR电路的暂态方程,从而得到不同电路暂态方程的一般分析方法。     

任意图同构判定及其应用

建立了任意图的伴随电路模型,使用电路分析方法求解伴随电路,通过解出的节点电压来确定原图拓扑结构的对应顶点,并由此提出了可应用于任意图的同构判定算法.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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