PC机与多台单片机通信构成小型集散控制系统

介绍采用一台工业PC机与多台单片机通信组成集散控制系统的方法。单片机作为下位机,完成对现场控制参数的采集并发出控制信号;PC机作为上位机,完成各种复杂算法的运算并将运算结果传送给下位机。此种控制方式充分利用了PC机与单片机的优势,对多台退火炉的集中温度控制是非常适用的。     

用VB5.0实现PC机与多台单片机控制系统的多机通讯

在分布式控制系统中,采用PC机作为上位机,调度多台下位机,从而实现计算能力强,容量大的分布式控制系统。VB5.0为新一代上位机编程工具,其具有可视化编程特点,可实现良好的人机界面。本文介绍了用VB5.0实现与多台单片机通讯的原理、方法。     

电网分析仪与PC机间串行通讯的设计与实现

文中研究了PC机和电网分析仪组成上位机和下位机之间的通讯过程,该通讯过程采用MODBUS协议。给出了用VB实现上位机监控软件的方法和下位机对上位机的通信实现     

用串行通讯构成工业控制小型集散系统

以串行通讯为基础,由一台ＰＣ机和几台Ｉｎｔｅｌ５１单片机构成的步型集散控制系统,使用自定义的简单通讯协议。上位机分时,循环向各下位机发送信息,被点名的下位机在时间内作出应答,传送的信息中,每一字节都包含地址信息。     

小型智能分装仪的软件设计

本文将PLC的可靠性与PC(Personal Computer)的可控性相结合,研制了电脑自动控制的小型智能分装仪。上位机(计算机)界面采用VB进行编程,通过RS232通讯口使用通讯协议MEWTOCOL完成上位机PC与下位机PLC之间的通信。     

PLC的1:N网络监控系统

对三菱FX系列PLC的1:N网络的构成进行了研究,阐述了实现上位机(PC)和下位机(PLC)、下位机(PLC)和下位机(PLC)之间的实时通讯及组成1:N网络监控系统的方法.     

车载智能通讯系统的研究

主要研究了车载智能系统的数据采集及上、下位机间的通讯，并给出了PC机和单片机间串口通讯的软、硬件设计方案。     

AT89C51单片机和PLC及PC机的通信

介绍了以226CPU作为下位机与PC机(上位机)和多台AT89C51开发的仪表的串行通信.着重介绍了通信协议的设计及PC机、PLC和单片机的通信程序初始设置和相关的程序流程.     

基于现场总线的等离子体表面处理监控系统的设计

设计了一种基于现场总线的等离子体表达处理工艺计算机监控系统,该系统采用现场总线组网,主控机采用工业PC机,下位机为PIC单片机,通过智能仪表及执行机构等,实现了用一台工控PC机管理多台PIC单片机,完成了多台等离子体表面处理设备的实时测控。     

基于现场总线的等离子体表面处理监控系统的设计

设计了一种基于现场总线的等离子体表面处理工艺计算机监控系统.该系统采用现场总线组网,主控机采用工业PC机,下位机为PIC单片机,通过智能仪表及执行机构等,实现了用一台工控PC机管理多台PIC单片机,完成了对多台等离子体表面处理设备的实时测控.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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