动态物位测定系统的组成和测量原理

在分析国内外各种物位检测方法的基础上，结合工厂实际要求，提出在特殊工况条件下用应变式传感器测量散粒体颗粒动态物位的新方法．建立了散粒体颗粒动态物位分布的数学模型，并以此设计高精度全桥式电阻应变传感器，信号调理采用集成2831电路，以非常简洁的方法实现传感信号的调理．应用表明这种方法能较好地解决特殊工况下散粒体颗粒物动态物位测量的问题．     

均匀传输线理论在物位传感器中的应用

从均匀传输线理论出发，推导出电容式物位传感器挂料层的电阻与传感探极和挂料层以绝缘层为介质所形成的电容的容抗在数值上相等，由此得出通过测量传感电极的复数阻抗来消除挂料误差对测量的影响。理论与实验证明，该方法在测量具有粘附性的导电物料时对克服挂料引起的误差有很大的实用性。     

浅析智能开关的设计

本文介绍的这种开关是集单片机、各类传感器、电力开关于一体新型开关,是未来的发展方向。     

MPX压力传感器在气柜保护中的开关应用

介绍了固态压力传感器MPX系列中的压力开关敏感元件的特性,并给出了由MPX压力传感器组成的开关应用电路.该电路的设计充分利用了MPX压力传感器的开关应用功能.使用较少和常用的元、器件,设计出了能满足工程应用的实用电路.化工生产中常用气柜来作为各种气体的存贮和缓冲设备.但气柜常有被抽瘪的情况发生.将该套由MPX压力传感器组成的压力开关装置应用到气柜的运行保护中,可有效地防止气柜被抽瘪的事故发生.     

基于串行扩展技术的霍尔液位传感器

目的针对低精度的液位测量,设计一种液位测量传感器。方法利用开关霍尔元件和串行扩展技术。结果设计了测量电路、信号处理电路和软件。结论传感器性能稳定,设计方案可行。     

自感式料位数字传感器

设计了一种新型料位传感器及其单片机控制系统。它可应用在钢厂除尘器设备上粉尘料位的检测。针对钢厂粉尘的铁磁质性质,设计整个自感线圈,固定在传感器的支撑杆上,在料位到达时,自感线圈中的感生电流显著变小,应用单片机进行控制,采集其开关量,可实现料位的连续检测,单线圈在料位到达时断电,卸料后恢复通电,即去除了铁心的磁性,又减少了线圈发热,同时线圈采用高性能漆包线,并对其进行散热处理。该传感器可以从室温到100℃的变温环境下正常工作,其结构简单可靠。     

传感器在印刷机中的应用

阐述了传感器的工作原理及特性.以接近开关为例,讨论了传感器在印刷机中的应用.     

无位置传感器开关磁阻电机伺服传动系统研究

该文在对比几种无位置传感器方法分析开关磁阻电机伺服传动系统特点的基础上 ,通过相电流和相电流相对转子位置角变化率的研究 ,建立了基于查表法的无位置传感器方法 ,并进行MATLAB仿真研究。结果表明 ,这种无位置传感器方法的实用性     

MPX压国传感器在气柜保护中的开关应用

介绍了固态压力传感器MPX系列中的压力开关敏感元件的特性,并给出了由MPX压力传感器组成的开关应用电路,该电路的设计充分利用了MPX压力传感器的开关应用功能,使用较少和常用的元,器件,设计出了能满足工程应用的实有电路,化工生产中常有气杠来作为各种气体的存贮和缓冲设备,但气柜常有被抽瘪的情况发生,将该套由MPX压力传感器组成的压力开关装置应用到气柜的运行保护中,可有效地防止气杠被抽瘪的事故发生。     

智能电动玩具小汽车的控制

本文介绍了智能电动玩具小汽车控制系统的硬件电路以及软件算法设计。控制系统的硬件部分主要包括传感器、控制器、功率放大和电机驱动模块。传感器采用反射式红外开关管,控制器使用8位MCS51系列单片机89C51,驱动模块采用TTL电平直接控制的L298驱动直流电机。软件主要是PWM算法和电机制动。     

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