基于FPGA和PCI总线的数据采集卡设计

本文提出一种基于FPGA和PCI总线的数据采集卡的实现方法。该采集卡VXFPGA为控制核心进行多通道数据采集,并通过PCI总线进行数据传输,有效地解决了数据传输和处理的实时性。本文主要阐述该采集卡的系统设计原理及FPGA各个模块的逻辑功能实现。     

PCI总线检测器的设计

对 PCI总线的性能作了简单的介绍 ,针对 PCI总线的检测问题给出了一个设计实例。提出了使用硬件电路和软件控制的方法去显示PCI总线上的信息 ,以达到确定从 CPU到 BIOS整个一段总线的传输是否正常的目的。     

双通道数据传输PXI总线接口控制程序设计与实现

PXI总线是NI公司在计算机外设总线PCI的基础上实现的新一代仪器总线,已经成为业界开放式总线的标准。基于PXI总线的数字化仪器模块是现代测试系统中重要的一种数据记录与处理设备。本文将介绍一种基于PXI总线的双通道信号解调板的PXI总线实时性传局部总线应用提供了宝贵的经验。     

基于PCI总线的RS485接口卡的设计

随着PCI总线的出现和发展,各种基于PCI的数据接口卡越来越被普遍使用。本文介绍了一种基于PCI总线的RS485通讯接口卡的设计,该接口卡通过选用PCI桥接芯片PCI9025来实现PCI接口。     

基于PCI总线的CAN接口卡设计

论述了PCI及CAN总线的主要特点,阐述了PCI通用状态机设计,提出一种利用SJA1000实现PCI总线CAN接口卡的设计方案和基于VHDL语言的PCI通信状态机的软件设计方案,给出了PC驱动程序的详细结构和实现.     

一种基于视觉的三维轮廓检测系统

设计了一套基于机器视觉的三维轮廓检测系统,用于生产线上零件三维轮廓的在线检测.该系统主要由基于CCD的激光三角法数据采集模块、基于FPGA的嵌入式数据处理模块、基于USB总线的数据传输模块和基于OpenGL的图形显示模块组成.该系统结构紧凑,对于生产线上的高速运动物体,也能获得较高的分辨率.数据处理模块也允许多种算法在该平台上运行,便于实际应用中选择最优算法.通用的USB数据传输接口能提供较快的数据传输速度,允许在开机状态下插拔设备,避免了PCI等插槽式数据传输方式需要打开机箱的缺点.基于VC的显示模块,将检测结果以图形方式显示出来,更加直观,并且方便实现人机交互.     

CDMA2000基站模块中PCI和Local总线冲突问题的研究

CDMA2000 BTS(基站收发信机)中的信道处理模块与主控模块之间的通信存在异常导致系统无法启动.为了找出故障的根源,对基站系统进行逐层深入的分析,并且进行了大量的时序测试工作.故障最终定位为数据在PCI总线与Local总线之间转移时存在冲突,产生了一个异常的重读操作,导致基于FIFO架构的存储数据存在丢失.问题的定位对于研究CDMA2000基站的架构、对于正确应用PCI和Local总线,具有参考价值.     

PCI总线接口设计与数据采集的实现

介绍一种基于PCI总线在高速印刷图像检测中所用数据采集传输系统的实现。阐述了PCI总线的特点，PCI接口芯片的功能。所采用的PCIS5933芯片完全符合PCI2．2技术规范的标准。本数据采集卡具有价格低廉、性能稳定、精度较高的优点．可广泛应用于工业控制、科学研究方面。     

下一代总线标准PCI Express

分析了PCI总线标准的缺陷,介绍了PCI Express总线产生的背景和PCI Express总线的主要技术优势,剖析了PCI Express总线的系统架构和分层的体系结构,并对每一个层次给出了详细说明．描述了PCI Express总线物理连接器的结构。     

PCI总线与CAN总线通讯研究

为了方便工业控制计算机接入控制器区域网络CAN总线。提出了一种基于PCI总线与CAN总线的通讯设计方案,划分了PLX9052与LPC2292之间的SRAM以加快两者之间数据传输,并实现了Linux系统下的PCI驱动和微控制器LPC2292上CAN总线的固件程序,为保持适配卡的兼容性,采用通用滤波方式（单滤波和双滤波）的文件,完成滤波功能,从而实现了工业控制计算机总线与CAN的高速连接。     

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