数字式温度测量系统的设计

采用单片机和数字式温度传感器DS18B20,设计一种温度测量系统.介绍51单片机和温度传感器DS18B20,以及温度传感器DS18B20的工作时序.给出温度测量系统的硬件电路和软件程序设计的方法,以及51单片机对DS18B20的初始化程序,读、写等相关程序.实现了对测量温度的采集和显示.实验表明,该系统具有测量精确,测量范围大,体积小,便于控制及结构简单、抗干扰能力强、适用范围广等优点.     

基于单片机的温度远程显示系统设计

介绍了利用单总线数字温度传感器DS18B20及单片机实现温度测量,并利用RS-485总线实现远程监控的一种智能温度监测系统的设计。系统的主要硬件是AT89C51单片机、RS-485总线和数字温度传感器DS18B20。可实现对环境温度信号的采集并把采集到的信号送给单片机进行处理,然后通过与单片机相连的LCD液晶显示屏显示温度。另外,单片机可以通过自带的串行接口通过RS-485总线与PC机进行通信,PC对现场温度进行实时监测。硬件设计包括三个部分,分别是单片机外围电路部分,单片机和传感器的连接部分,PC机与单片机的连接部分。软件设计包括DS18B20传感器的读写程序,LCD液晶显示屏的显示程序,PC机和单片机的485通信程序。     

单片机和DS1 8B20组成的多点温度测控系统

介绍了单线数字式温度传感器DS18B20的基本原理,给出了用89C51单片机和DS18B20构成的多点温度测控系统的硬件电路及软件设计.     

基于DS18B20的单片机温度测量系统

根据数字温度传感器DS18B20的单总线结构特点,利用简单的接口与单片机组成一个温度测量系统,通过键盘和LED显示数码管对系统进行控制和显示,给出了用DS18B20和AT89C51单片机构成的温度测量系统的应用电路和参考程序。     

基于DS18B20的多点温度检测系统

该文提出了采用单总线数字式温度传感器DS18B20和单片机组成的新型智能多点温度检测系统。在文中,首先介绍了DS18B20的基本特性,然后给出了相应的硬件接口电路、软件流程及主要程序代码。DS18B20具有直接输出数字信号、单总线接口、成本低等优点。经试验,基于单总线器件DS18B20的多点温度检测系统测量温度准确、测温范围宽、体积小、控制方便。     

基于单片机超声波测距仪的设计

本文采用以AT89S51单片机为核心的低成本、高精度、微型化数字显示超声波测距仪的硬件电路和软件设计方法。在分析超声波测距原理的基础上,设计了基于单片机控制的测距系统;考虑到温度对超声波传播速度的影响,阐述了DS18B20在测距时的温度补偿方法。对超声波的发射电路和接收电路、DS18B20温度采集电路、LCD显示电路做了硬件制作和软件设计;对系统进行了误差分析。相关部分附有硬件电路图、控制程序。该系统硬件结构简单、工作可靠、有良好的测量精度和灵敏度。     

基于DS18B20的单总线数字温度计

介绍了一种基于单片机AT89S52和数字温度传感器DS18B20来进行温度测量的单总线数字温度计,包括温度传感器芯片的选取、单片机与温度传感器接口电路的设计,以及实现温度信息采集和数据传输的软件设计。DS18820数字温度传感器是单总线器件与51单片机组成的测温系统,具有线路简单、体积小等特点,而且在一根通信线上,可以挂接多个DS18B20,因此特别适合构成多点温度测控系统。     

基于AT89C51单片机与DS18B20的温度测量系统

介绍了单总线数字温度传感器DS18B20的特性及工作原理,给出了AT89C51单片机与DS18B20构成温度测量系统并详细介绍利用汇编语言编程实现对DS18B20访问。实际测试结果表明这种测温系统转换速度快、精度高,整个系统具有稳定性强等特点。     

基于PIC18F248的温度监控系统的研究

为了监控大电流磁体电源的温度变化,采用微处理器PIC18F248进行实时监控。首先设计传感器DS18B20的调理电路,通过添加共模抑制线圈提高系统的抗干扰能力,然后利用CAN总线完成多路多点的数据采集,最后采用LabVIEW驱动CAN接口卡并设计系统接收界面。     

DS18B20在单片机温控系统中的应用

DS18B20新型单总线数字温度传感器集温度测量和A/D转换于一体,直接输出数字量,与单片机接口电路简单。作者介绍了一种基于DS18B20和AT89C2051单片机的温度测量及控制系统的硬件结构及汇编程序设计。     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has