电子校准件的Window CE驱动开发

电子校准件由于使用方便快捷,测量稳定精确,已普遍应用在台式矢量网络分析仪的校准中。而手持式矢量网络分析仪由于使用WindowsCE操作系统,若要正常使用电子校准件,需开发其在WindowsCE系统下的USB驱动。本文介绍了一种电子校准件的流驱动开发技术。     

矢量网络分析仪的测量精度

矢量网络分析仪具有强大的测试功能,其测量精度主要取决于校准标准件的性能、误差修正技术所决定,本文分别讨论了这两方面对矢量网络仪测量的影响。     

网络分析仪及其应用

导出了双口网络的特性参数和Ｓ参数，分析了网络分析仪的工作原理，给出了利用网络分析仪测量网络参数的方法。     

基于矢量网络分析仪的信道链路标校方法

卫星导航系统中收发信道链路的时延标定与测量对系统性能和定位精度具有重要意义,介绍了常见的收发设备零值标校方法,重点分析了基于矢量网络分析仪的绝对时延测量方法,通过校准和测量原理以及测量精度的比较,突出了基于矢量网络分析仪的梳状波发生器法(SMC+Phase)进行时延测量的优势。     

矢量网络分析仪的误差分析和处理

矢量网络分析仪的主要测试目标是电磁波,通过对电磁波的测试,可以为微波元器件的应用和设计的提供参考,促使微波元器件的功能性可以得到有效的发挥。但是在实际的测试过程中,误差是切实存在的,影响测试的效果和测量的质量,使得的测量结果不能有效的对真实情况进行反应。为此,需要科学的展开误差分析工作,为误差处理提供助力,提高微波元器件的功能性。以下该文就矢量网络分析仪误差分析展开探讨,结合实际的测量情况,提出有效的误差处理措施,旨在为相关技术人员提供参考,促使矢量网络分析仪的功能性可以得到进一步提升,提高其测量的精确度和可靠性。     

矢量网络分析仪3mm扩频技术

本文介绍了一种基于微波矢量网络分析仪实现3毫米频段扩频的技术方案及工作原理,重点对高本振谐波混频技术、毫米波定向耦合器设计制造技术、定向检波器技术、内置倍频源幅度及平坦度控制技术、毫米波校准技术等关键技术进行介绍。文末给出了应用本方案实现的3毫米矢量网络分析仪的成果及应用情况。     

基于虚拟仪器技术的薄膜电磁参量测量

基于谐振腔微扰技术,利用先进的矢量网络分析仪,结合虚拟仪器技术研制了一套测量薄膜微波电磁参量的自动测量系统．该系统可以方便、快捷地测量薄膜在微波频率下的复介电常数和复磁导率．图形化编程语言LabVIEW大大缩短了系统开发时间,提高了编程效率．     

基于反射和传输方式的误差网络校准方法

针对矢量网络分析仪的误差网络e00，e01，e11,e22，e30,e32六参数的求解，文中提出了一种新的基于反射和传输测试网络的方法，获得了误差参数的解，经过实验验证，该方法在5GHz频率范围内，测量值与理论值吻合得非常好。     

LVDS远距离通信电缆参数估计

随着数据传输系统对速度和距离要求的提高,为实现测量数据的高速远距离可靠传输,本文针对百米普通双绞线缆,建立了线缆的参数模型,通过最小二乘法估计出模型参数,并用矢量网络分析仪对线缆进行了测试。实验表明,所估计出的参数模型表征的衰减特性与矢量网络分析仪的实测结果具有较好的一致性,为分析LVDS信号通过双绞线高速远距离可靠传输提供了依据。     

同轴法测量微波吸收材料反射率研究

为了准确方便地测量微波吸收材料(RAM)的吸波性能,提出用HP8722ET矢量网络分析仪和APC-7mm空气线进行吸波材料反射率简便测量的同轴法.研究结果表明:该方法可以测量0.05～18 GHz范围内吸波材料的反射率,无需微波暗室等实验条件;在普通实验室条件下,可以不受外界电磁波的干扰准确测量吸波材料的反射率.单层与双层吸波材料的反射率测试结果表明:同轴法测试结果与理论计算值非常吻合,比弓形法具有更高的准确性.该方法可以应用于其他型号的矢量网络分析仪和同轴空气线构成的测试系统.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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