基于超声波的汽车防撞系统

在现有的汽车防撞系统中,主要都是使用雷达进行测距,这类系统的价格较高,不能大面积推广.在现有的汽车防撞系统上优化测距算法,采用超声波传感器进行测距,建立相关的防撞模型,根据不同的测量距离发出不同的报警信息.实验结果表明,在一定范围内报警信息准确.     

基于超声波的汽车防撞系统（英文）

在现有的汽车防撞系统中,主要都是使用雷达进行测距,这类系统的价格较高,不能大面积推广.在现有的汽车防撞系统上优化测距算法,采用超声波传感器进行测距,建立相关的防撞模型,根据不同的测量距离发出不同的报警信息.实验结果表明,在一定范围内报警信息准确.     

汽车防撞系统中的非接触式测距

以单片机为控制核心,采用模块化设计以及超声波传感器实现了汽车防撞系统的非接触式测距,有效解决了汽车倒车监控及报警问题。     

基于AVR单片机的超声波测距在倒车防撞中的应用

以AVR单片机ATmega16作为主控制器,结合超声波发射、接收模块DYP-ME007,巧妙地利用AVR单片机特有的输入信号捕捉功能,实现3cm～3.5m的非接触式距离感测,并实时显示距离和报警。分析了DYP-ME007模块的超声波测距原理,给出了测距系统的整体设计和硬件组成结构图,并具体阐述了系统软件设计过程并提供了程序框图。经实际测试证明本系统实现了超声波测距和报警功能。     

非同步方式电力机车防撞测距报警器

为了改变在矿山生产过程中运输环节经常发生安全事故的现状,开发了非同步方式电力机车防撞测距报警器,该系统利用超声波测距原理,结合单片计算机的控制和运算功能,采用独特的算法,实现了机动车车辆的识别、相对速度的动态显示和报警的功能。将现代化的技术转化为保障行车安全的措施。     

基于单片机的汽车全方位防撞系统设计

阐述了一种基于单片机的汽车全方位报警体系的设计,该系统主要将超声波测距与AT89C51单片机组合在一起,设计出一种具有高测量精度的汽车防撞报警装置。文章主要从该系统的设计原理、可行性分析、超声波测距以及系统软件设计方面加以阐述。通过对系统的理论及实际分析使系统在实际生活中充分发挥其系统的优越性,帮助司机构建一个安全的行车环境。     

一种汽车倒车防撞系统设计

文章采用超声波来测距,并结合红外避障技术的优越性,以51单片机STC89C52RC为控制核心,通过倒车雷达,实现测距的功能.显示电路测出的距离精确地显示出来;报警电路实现遇到障碍时的声光报警;车尾测障电路实现在驾驶员盲区范围内的防撞;汽车电控刹车电路实现汽车的自动刹车.此设计实现了汽车倒车雷达的各种基本功能,能够主动防御.为了提高超声波测距的探测精度,用推挽形式将方波信号加到超声波换能器两端,可以提高超声波的发射强度.输出端采用两个反相器并联,以提高驱动能力.此系统有效地降低倒车防撞系统的成本,其可靠性和抗干扰性能良好.     

基于单片机的超声波倒车雷达系统设计

利用超声波测距原理,出于低成本、高精度的目的,提出了一种基于单片机的汽车泊车防撞预警装置。本装置根据超声波发射信号及接收信号,自动判断与障碍物之间的距离,并实时显示及报警。主要由超声波收发模块、温度测量模块、报警显示模块及单片机控制模块组成。测试结果显示该系统测量精度误差为1cm,测量距离为0.1m到2m,该系统达到了较高的控制精度,硬件电路简单,工作可靠,有良好的测量精度和灵敏度。     

倒车防撞报警系统的设计

基于超声波测距原理,介绍了一种以单片机AT89C51为主控制器的倒车防撞报警系统。此系统在汽车倒车时自动启动,由装置于车尾保险杠上的探头发送超声波,遇到障碍物产生回波信号,传感器接收到回波信号后经控制器进行数据处理,判断出障碍物的位置,达到设定的距离时显示并播报。为了减小测距的误差在数据处理部分还采用了温度补偿和最小二乘法来修正距离。实验表明该倒车系统在30 cm~500 cm范围内可实现准确测距,具有可靠性较高、外围电路简单、实用性强等优点。     

基于ARM微处理器的语音报警系统设计与实现

介绍了由集成ARM微处理器的EX44B0开发板和语音芯片ZY1420A组成的语音报警系统的原理与实现过程。该系统具有报警速度快、报警直观、可靠性好、电路简单等优点。     

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     

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