电话智能遥控系统的设计与实现

电话智能遥控系统以单片机AT89C51和解码芯片MT8870集成电路为核心，通过电话实现对远程设备智能化控制．文章介绍了该系统的组成、工作原理及程序设计方法．同时对“振铃检测、模拟摘机、双音频解码及电器控制”等电路作了详细的说明．本装置适用于家庭、商店等场所，应用电话来控制电器设备．     

基于电话线控制与传输的复飞远程告警

本文介绍了基于电话线路进行远程控制与传输的告警器设计与实现方案.结合深圳机场双跑道运行条件下塔台的实际需求,提出复飞告警作为塔台与珠海建立联系的辅助手段.基于电话线路进行设计,可以最大程度利用现行深珠传输链路资源.     

基于PSTN网络的远程监控装置设计与实现

为实现某型装备任何时间、任何地点的远程监测控制,基于使用最为广泛的公用电话网,综合使用线路信号检测芯片判断线路状态、双音多频收发芯片接收发送双音多频信号进行命令交互,采用单片机集中控制制作完成。该装置在某型装备的远程监测控制使用中,经过固定电话、GSM手机、CDMA手机等方式,控制准确率均达到设计要求。该装置使用于语音编码速率低于8kb/s电话系统中,由于双音多频信号识别率过低,无法达到远程监控目的。     

基于MSP430单片机的多传感器家居安全告警系统设计

设计了一个以MSP430单片机为核心的多传感器现代居家安全告警系统．以MSP430G2553单片机为控制核心,采用多传感器集成的模块化方式进行设计,系统主要包括电源控制模块、信号处理模块、传感器模块、键盘控制模块、液晶显示模块及告警输出六个模块．传感器模块采用可扩展设计模式,告警输出采用分级设计模式,方便不同用户的需求．同时强化了系统自身安全的监控,双供电模式、自身震动监控、告警模块防爆设计、紧急告警模式等能有效的保证系统安全并在第一时间内发出告警信息．实验结果表明系统具备良好的稳定性和可靠性,达到实际使用要求．     

基于光电传感器的毛丝检测电路系统的研究

本文提出了一种能在粘胶长丝的络丝工艺过程中实时检测毛丝的方法，基于此方法设计了毛丝检测装置，该装置以毛丝检测电路为基础，使用89C51单片机作为系统的主控制器，通过信号处理电路，计数测量电路，功率调节电路，键盘显示电路，执行机构驱动电路，完成毛丝检测和计数的功能。经过实际运行表明，该系统测量稳定可靠，成本低廉，而且体积小。     

解决电话控制问题的方法探讨

该文对电话计费控制问题进行了探讨，介绍了一种话机外接硬件控制系统，用来防止长途受限用户非法拨打长途电话，并对授权用户显示和记录被叫号码及通话时间长。该文还描述了系统的总体框图、电路原理、设计原则及实现方法。     

DTMF接收器在程控电话上的应用

主要介绍单片机控制的ＤＴＭＦ信号接收器在程控交换机键控电话系统中的应用，详细分析了ＭＴ８８７０的内部结构和使用典型线路，描述了８０Ｃ３１单片机对ＭＴ８８７０接收器的控制工作原理，并应用该原理给出了设计长途电话控制加密器的电路方法。     

PI控制的故障电弧电流还原装置设计

针对故障电弧保护电器动作特性测试的试验周期长、效率低等问题，设计了基于PI控制的电弧电流还原装置.通过搭建Multisim与LabVIEW联合仿真环境对电流还原装置的硬件电路进行仿真，以此验证方案的可行性.同时调试硬件装置进行试验验证，对比原始信号与还原信号的时域、频域特征参数和THD值作为电流还原度指标.试验结果表明，电弧电流还原整体还原度良好，该装置基于原始电弧故障数据给电弧故障检测算法和AFDD产品测试提供了更加真实和便利的测试条件.     

家庭智能留言电路的设计

家庭智能留言电路的设计是针对家庭留言电路中门铃留言和电话留言的研究,主要实现门铃留言和电话留言两个功能。主要是由控制电路、电话振铃电路、电话摘机电路、语音录放电路、红外线反射电路、功率放大电路、数字集成电路及电源组成。该电路以控制电路为中心,控制电路检测到电话振铃电路和数字集成电路送来的信号,根据信号大小的不同,控制电话摘机电路的摘机或挂机和语音录放电路的录音或放音。     

基于CAN总线的煤矿供电系统线路保护装置设计

设计了一种对煤矿供电系统输电线路进行保护的装置.该装置以32位ARM处理器MB9BF518S为控制核心,以CAN总线为通信网络,实现了对煤矿供电系统输电线路电压、电流、有功功率、无功功率等参数的测量和监控,并可以对输电线路发生的短路、过电流、低电压等故障进行有效的保护.叙述了保护装置的总体功能和基本结构,给出了信号变换电路、CAN总线接口电路和开关量输入电路的设计方案,分析了电流速断保护和反时限过流保护的保护逻辑,并给出了保护装置的部分测试数据.该保护装置结构简单、操作方便、可靠性高,能够满足煤矿供电系统对输电线路保护的要求.     

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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