具有参数设置及统计功能抢答控制系统的设计和应用

为了克服传统的基于PLC开发的抢答器控制系统的功能简单、编程繁琐、系统扩展困难等缺点,本设计采用PLC、触摸屏、数码管、蜂鸣器等组成抢答器硬件系统.采用PLC功能指令进行编程,用触摸屏作为人机界面,开发的多功能抢答控制系统具有数值显示、声响报警、现场参数设置及实时数据统计分析等功能.现场测试结果与设计要求一致.     

数字竞赛抢答器的设计与实现

基于数字时序控制电路原理,采用元器件设计实现了一种显示倒计时的数字竞赛抢答器。该抢答器由组合逻辑电路中的编码器、锁存器、译码器,时序逻辑电路中的计数器和555定时器组合而成。该抢答器具有手动复位功能,倒计时功能和显示功能。经测试表明,该抢答器可以准确显示倒计时时间和抢答号码,反应灵敏,工作性能稳定可靠。     

基于FPGA的多路抢答器设计与仿真

针对现有抢答器性能不稳定、不精确等问题,以FPGA芯片EP2C35F672C8为实现载体,通过QUARTUSII9.0和VHDL设计并实现一款新颖的八人四组抢答器.采用VHDL设计各模块并生成逻辑符号图,按照抢答器的工作原理,将逻辑符号图级联构成抢答器的顶层电路,通过功能仿真、下载验证目标文件.实验结果表明,该抢答器能...     

基于EDA技术的抢答器的设计与实现

从实际应用出发,利用电子设计自动化(EDA)技术,用可编程逻辑器件设计具有扩充功能的抢答器.该抢答器利用Protel99完成了原理图设计、利用VHDL完成了控制主电路设计,具有数字显示电路、倒计时显示电路、违犯规定电路、编码译码电路功能,并利用的MAX-PLUSⅡ工具软件完成了编译仿真验证;硬件选择Altera的MAX740005系列的EPM7128LC84-15芯片来实现抢答器的系统功能,该抢答器具有很强的功能扩充性,应用效果良好.     

基于74系列八路抢答器的设计

本文介绍了一种用74系列常用集成电路设计的数码显示八路抢答器的电路组成、设计思路及功能。数字抢答器由优先编码电路、锁存器、译码电路将参赛队的输入信号在显示器上输出;经过布线、焊接、调试等工作后数字抢答器成形。     

PLC应用于抢答器中的三个编程设计技巧

可编程序控制器（简称PLC）是以微处理器为核心,将自动化技术,计算机技术和通讯技术融为一体的新型工业自动控制装置。用PLC做抢答器的核心控制元件,则抢答器的各项功能及如何操作均由存储在PLC内的控制程序来决定。控制程序就是抢答器的灵魂。本文以三菱FX1S的PLC为控制器,介绍PLC应用于知识竞赛抢答器中控制程序的三个编程设计技巧。     

基于AT89S52单片机的抢答器设计与实现

AT89S52单片机是一个低功耗，高性能CMOSS位微控制器，本文基于AT89S52单片机的功能，从硬件和软件方面设计TAT89S52单片机的抢答器。     

FPGA之基于Verilog语言实现优先抢答锁存模块的实现①

抢答模块和锁存模块的基本实现是抢答器,抢答器是比赛和竞赛中一种常用且必备的装置,其原理是一种非常典型的数字逻辑电路,其中含有时序逻辑电路和基本逻辑电路组成,其项目包含D触发器,锁存器,分频器,7段数码管的译码器,主持人按开始按钮示意开始抢答,本文将使用Verilog HDL语言实现其功能,并通过对抢答器电路设计的分析加深对其功能实现电路的认识和理解。     

基于单片机的八路抢答器设计与实现

以AT89S51单片机为核心器件,设计实现了八路抢答器系统.软件仿真和硬件实现的结果表明该系统实现了八路抢答器的功能.具有反应快、操作简便、实用性强等特点.     

用数字集成电路设计时间鉴别电路

论述了用数学集成电路设计时间鉴别电路，分析了设计抢答器电路的基本方法，给出了两种电路简单，原理清楚并且实用的抢答器电路。     

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