基于AT89S51单片机的光栅智能测量仪的设计

本文介绍了用AT89S51单片机和光栅传感器设计一种智能测量仪。利用光栅传感器把位移转换成电脉冲的特点,同时利用AT89S51单片机的低功耗、高性能和高集成度的优点,阐述了该测量仪的测量原理、方案实现和软件设计。主要用于与光栅尺配套进行位移测量。     

提高光栅测距精度的四倍频判向电路

光栅是一种精密的位移检测装置，它的输出很容易和计算机接口．本文介绍了一种可提高光栅测距精度、工作稳定可靠的四倍频判向电路     

基于CMOS图像光栅传感器的位移测量系统的实现

目前在科技研究、工业生产等各行业中,对于位移的高精度测量都是不可或缺的。利用光栅传感器完成测量是目前的主要方法。光栅传感器利用光电转换的原理将位移转换为电信号,该信号经过整形、细分后输出给后级电路完成对信号的处理,最后得到位移大小方向。本文在分析光栅传感器工作原理的基础上,提出借助CMOS图像传感器代替传统的硅光电池检测莫尔条纹,完成信号的细分,实现对位移的高精度测量。文中介绍了整体电路的设计和单片机系统的硬件及软件流程。     

可编程控制器对光栅传感器信号进行高速处理

针对采用PLC进行光栅位移传感器信号高速处理的有关问题进行了详细的分析，对光栅传感器输出信号的形式及其信号处理电路进行了重点阐述。尤其是对PDC9301鉴相倍频集成电路的封装形式、管脚排列以及应用电路进行了详细的说明，并从实用的角度出发介绍了光栅传感器信号与PDC9301及PLC连接电路，叙述了可编程序控制器PLC程序的设计方法。     

单片机控制的光电测速仪

提出了一个用８０３１单片机和光电编码器组成的转速与转角测试方案,介绍其实现的基本原理和结构特点,给出了接口电路和软件设计方法。由于采用了单片机和光电传感器,该系统具有硬件电路简单、测量精度高、性能稳定可靠等优点,其适用于自动控制、自动检测及各种转速与方位角的测量与控制等领域。     

光栅传感器及在轮毂椭圆度测量中的应用

阐述了光栅传感器的测量原理,并利用光栅精密测量的特性,开发了车轮毂椭圆度的测量装置。该装置应用光栅传感器采集位移信号,采用光栅莫尔条纹和光电转换原理将被测位移量转换成数字脉冲信号输出,采用脉冲辨向及四倍频细分电路以实现信号方向识别及提高测量精度,将产生的脉冲信号通过单片机控制程序实现数字显示。     

端电压位置检测电路中无源低通滤波器的优化仿真

无位置传感器直流电机以其众多的优点得到广泛的应用，位置的检测可通过一个电子式的端电压检测电路来获取。借助于Madab仿真软件，通过计算机仿真，从减小电动机转矩脉动的角度对检测电路中的滤波器进行了仿真研究，并对仿真结果进行分析，得出了一些有用的结论。     

纳米级位移传感器接口电路的研究

从降低噪声的角度，研究了用于微位移传感器的接口电路，介绍了几个主要环节的设计与参数选择，该接口电路及成功用于纳米级位传感器中。     

机床低速爬行参数的测试与分析

提出了一种以周期法测试机床低速爬行参数的方法,并设计了一套以直线式光栅位移传感器的基准件,配以接口电路和微机的测试与分析处理系统,实现了集数据采集,分析与处理为一体的测试分析方法。     

一种新型船用油分浓度检测仪

采用双入射通道相互切换的方法,设计出一种新型的船用油分浓度检测仪．检测仪由传感器、信号调理电路、A／D转换电路、单片机控制电路和符合IEEE1451．2标准的电子表格TEDS及与外部网络相连的标准TII接口组成,保证了油分浓度的检测精度,有利于保护海洋环境．     

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.     

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     

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

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