非线性电路与系统的计算机符号仿真程序

本文介绍了一个非线性电路与系统的计算机符号仿真程序ＳＡＰＮＣ，它可以对线性时不变电路、弱非线性电路、单变量强非线性高阶电路和时变电路进行符号分析。该程序便于有关专业的学生、教师及研究者使用，对于提高洞察电路性能的能力，特别是提高对非线性电路和非线性机理的理解能力及指导电路设计是有价值的辅助工具。     

大线性电阻电路的单故障诊断的一种方法

提出了非线性模拟电路故障诊断的一种测前模拟法。应用伴随电路及特勒根定理导出故障诊断方程，用等电位屏蔽技术识别故障，非线性元件用其工作点参数等效线性化，可对故障电路逐级分块诊断，适用于大规模线性和非线性模拟电路。     

非线性电阻电路的单故障诊断的一种方法

提出了非线性模拟电路故障诊断的一种测前模拟法．应用伴随电路及特勒根定理导出故障诊断方程，用等电位屏蔽技术识别故障．非线性元件用其工作点参数等效线性化，可对故障电路逐级分块诊断，适用于大规模线性和非线性模拟电路．     

二极管非线性应用中两个问题的简析

二极管非线性应用时，在混频电路中的线性等效网络及在检波电路中输出音频电压的计算。     

蔡氏电路静态非线性子电路的直接设计方法

首先总结蔡氏电路中静态非线性电路的两个并联限幅运算放大器构成分段的线性负电阻特性的电路结构,分析这种电路结构的不足之处是负电阻非线性的构成方法是两个不同折点线性叠加构成的间接方法.提出由一个负电阻电路产生分段非线性的非线性正电阻直接构成方法,指出这是一种钳位电路,设计出两种类具体电路,分别给出了电路仿真实验结果,分析了电路误差并指出这一误差并不影响电路性能的原因,也给出进一步修正误差的设计方法,分析了物理电路设计的问题.     

一个新的非线性电容混沌电路的证明

选取一个含分段线性负电容的三阶自治电路,根据拓扑共轭的概念,归纳总结一般性的分段线性向量场线性共轭和线性等价关系.利用共轭等效判据,证明了非线性电容三阶自治电路与蔡氏电路非线性共轭.说明本电路具有潜在的研究价值,属一类能产生双涡卷混沌的新三阶自治电路.     

含非线性时变互感电路的计算机辅助分析

基于电路理论和数值积分和原理，导出非线性时变互感关于梯形算法的电路模型，提出一种便于用计算机对含非线性时变互感电路进行瞬态分析的方法，将含非线性时变互感电路的瞬态分析简化为若干非线性时不变电阻性电路的直流分析。     

用分段线性化法分析受迫二阶非线性电路的混沌振荡

采用分段性线化方法，分析了一个由线性电感，线性电阻，非线性电容，以在正弦电压源所构成的串联电路，电容的库伏特性用５段折线特性逼近，计算机仿真结果表明，分段线性化方法能够揭示电路的非线性动态演变过程，只是在某些细节上有所偏差，文中还用Ｍｅｌｎｉｋｏｖ方法导出存在横截同宿轨道的条件。     

负反馈能改善阻容耦合放大器中何种失真？

信号辅入最大电路后，由于放大电路中存在非线性元件和线性电抗元件，使输出信号失真。对阻容耦合放大器而言，当放大电路引入负反馈后，只能改善非线性失真，及线性失真中的幅度失真，不能改善线性失真中的相位失真等。负反馈展宽了最大电路的通频带，但不等于改善了频率失真。     

低阶混沌电路非线性力学特性的实验研究

通过对实验对二阶非自治混沌电路，三阶蔡氏电路和四阶非自治混沌电路进行了详尽研究，证明这些电路能够产生复杂的非线性动力学行为，以电路实验数据为依据，首次绘制出两个混沌电路的稳定岛图。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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