基于单片机的水浴温度控制系统的设计

介绍了基于89C52单片机的水浴温度控制系统硬件电路的组成、设计方法和工作原理．PT100温度传感器和精密电阻构成的电桥测量电路输出微弱的电压信号．AD620组成的精密放大电路完成调零和放大后送到A／D电路，再将模拟信号变换成数字信号．单片机根据输入量和设定量进行模糊运算，输出--路开关量和--路数字量．开关量控制制冷系统，数字量经D／A变换后通过调功模块控制加热量将温度控制在设定值。     

通用CAN节点电路的设计及其应用

介绍一种通用CAN节点的电路结构、相关应用程序及在工业中频感应加热设备控制现场总线中的应用。多功能CAN节点线路板上包含11路12位模数转换，8路开关量输入，3路开关量输出，1个RS—232S微机通信串行口，1个CAN通信口，可作为通用CAN接口用于自动控制系统中数据采集器及上位微机的转换接口。     

多路CAN总线转换卡的设计

针对在工厂监控系统中，CAN总线的监测节点数目受限制的问题，采用了高速低阻抗电子开关MAX4684，设计了多路CAN总线转换卡的硬件电路和软件编程．实验结果表明，所设计的多路CAN总线转换卡简单实用，可靠性高，成功地解决了工厂监测系统中的实际问题。     

通用CAN节点电路的设计及其应用

介绍一种通用CAN节点的电路结构、相关应用程序及在工业中频感应加热设备控制现场总线中的应用。多功能CAN节点线路板上包含11路12位模数转换,8路开关量输入,3路开关量输出,1个RS-232S微机通信串行口,1个CAN通信口,可作为通用CAN接口用于自动控制系统中数据采集器及上位微机的转换接口。     

多功能通用控制器MGC

本文推出了一种多功能通用控制器ＭＧＣ（Ｍｕｌｔｉ－ｆｕｎｃｔｉｏｎＧｅｎｅｒａｌＣｏｎｔｒｏｌｌｅｒ），它为用户提供了８位开关控制量；两组４个互锁开关控制量；４路数字循环开关控制量；４路模拟循环开关控制量；２路市电（５０ＨＺ）调压输出。文中对ＭＧＣ的技术背景、设计思想、工作原理作了详细介绍。     

基于CAN总线的电力调配微机监测分析网络系统

介绍一种基于CAN总线的电力系统电力调配微机实时监测分析网络系统设计。由CAN总线监测节点的PC机械成的高可靠系统实现对多路模拟量和开关量的检测,并对电压和电流信号进行故障录波、快速傅叶变换和数据分析。因此,系统可快速对故障线路做出判断并执行相应的控制。     

通信电源设备集中监控系统中的开关量采集

将电源系统中各种开关量归结为３类进行了讨论。针对通信电源系统的特殊性，提出了开关量采集的技术要求及采集接入方式，并就所采用的调理技术进行了详细分析。分析了３种开关量采集电路及其运行情况。     

电动汽车车载充电器辅助电源的高效设计

为了满足电动汽车车载充电器系统辅助电源要实现宽范围电压输入和多路隔离输出的实际需求,选择单端反激式多路输出作为辅助电源主电路拓扑,详细介绍了其主电路中高频变压器、RCD电路和输出电容设计步骤及参数确定依据.控制系统采用电压外环和电流内环相结合的控制方案,其中电流内环采用峰值电流控制,基于Iw1691控制芯片将自适应多模式控制和谷值开关控制相结合,减少开关管开关损耗,实现系统的高效运行.最后,通过系统仿真测试和样机测试证实设计方案的合理有效性.     

DSP+IPM的异步电机变频调速系统设计

通过设计异步电动机的变频调速系统,其主电路采用交-直-交型电路形式,控制方式采用恒压频比(U/F)控制策略,根据系统参数对电路器件进行参数计算和选型,采用智能功率模块(IPM)作为逆变电路功率开关器件,同时以TI公司的DSP(TMS320LF2407A)作为控制核心来提高系统的精度和稳定性。实验及仿真结果表明该驱动系统工作性能稳定、抗干扰性强,具有很高的应用价值。     

多路开关遥测遥控系统

提出一种通用于工业自动化中的多路开关遥测遥控系统，主要由多路开关采集发送单元和多路开关数据接收单元组成。每对收发单元可实现１５个开关量的测控，并可以方便地进行级联或并联以组成更多开关量的测控系统。系统全部由硬件构成，具有体积小、成本低、抗干扰、灵活方便、测控距离远、通用性强等优点。     

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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