数控直流电流源

采用高性能单片机C8051F020作为数控直流电流源的控制和测量核心,实现了电流设置、控制、输出、测量和显示.采用C8051F020内部的两路12位DAC电压输出,通过通道切换方式实现大电流和小电流的高精度指标要求;采用C8051F020内部的A/D实现负载电流的采样.通过控制继电器选择合适的主电源电压,提高了电源效率.系统还通过保存电流设置值,实现了普通旋钮仪表的位置调节记忆功能.     

μC/OS-Ⅱ实时操作系统与C8051F020单片机的结合

介绍了μC/OS-Ⅱ实时操作系统和Silicon Laboratories公司的新型低功耗单片机C8051F020,并且将该操作系统成功地移植到C8051F020单片机上,顺利地实现了多任务的设想,展示了嵌入式系统良好的应用前景.     

基于C8051F020的16位PWM信号控制

可编程计数器阵列PCA0模块接收来自C8051F020单片机的数字信号,输出16位PWM触发信号控制变换电路。在产生PWM信号的同时,使用C8051F020单片机的12位ADC0窗口检测器进行输入值超范围报警,并在程序中对PCA0的值进行了修整,实现了PWM控制信号频率可调。     

三相交流电参数综合监测仪的研制

文中介绍用C8051F020单片机和DSP智能芯片来搭建系统实现的三相电参数综合测试系统,系统充分利用C8051F020各种内部资源,使得整个系统设计简单,易于实现,应用领域广泛。     

基于高速C8051F单片机的新型补偿式隔离变压器

以C8051F020为控制核心,设计了新型补偿式隔离变压器,介绍了SoC（System on Chip）高速单片机C8051F020。     

C8051F020在高速通信中的应用

介绍C8051F020在高速通信中的应用。一方面,C8051F020通过RS232方式接收来自PC机的大量数据,并保存到FLASH中。另一方面,C8051F020按规定时序信号,通过RS422方式把FLASH中的数据发送出去。     

基于C8051F020单片机的新型配料控制器设计

首先介绍了高速混合信号系统级芯片（SOC）C8051F020单片机的主要特点，然后介绍了一种基于C8051F020单片机的新型配料控制器的软件和硬件设计方法。以C8051F020为核心的配料控制器，结构简单、可靠性和稳定性高、实时性好、调试容易、编程简单、操作方便，具有广阔的实用前景。     

基于C8051F020的数据采集处理系统的设计与实现

本文采用C8051F020单片机作为核心处理器,设计一个数据采集与处理系统,对C8051F020单片机、数码管驱动和键盘扫描控制芯片CH451的特点进行了介绍,重点介绍了系统的硬件设计电路和系统的软件设计。该系统基于单片机为主控芯片实现数据采集、传输及处理的功能,通过采集压力、温度和流量数据,以模拟信号的形式传输到C8051F020单片机,并在数码管上显示出来,并对数据和采集的时间进行存储。该系统数据采集精度好、可靠性高、成本低、功耗低,可以应用在各种试验的数据采集和处理中,具有很高的工业使用价值。     

嵌入式Web服务器的研究与实现

介绍了基于C8051F020单片机的嵌入式Web服务器系统设计与实现方案。阐述了系统的软硬件实现方法，并说明了实时操作系统μC／OS-Ⅱ的移植。以及嵌入式TCP／IP协议栈的引入和网络驱动程序建立的实现过程和方法。     

转子动不平衡在线检测的数字相关滤波方法

提出了一种转子动不平衡的检测的数字相关滤波算法,采用MatLab软件仿真再现了其在较大噪声背景下提取正弦波幅值和相位的能力,结合摩托车磁电机动不平衡检测系统设计实例,实现并验证了该方法的有效性,并给出了基于C8051F020单片机的动不平衡在线检测中的具体实现方法.结果表明,数字相关滤波方法在转子动不平衡检测中具有很高的识别精度和抗干扰能力,可用于各种转子的动不平衡检测.     

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.     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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