CompactPCI/PCI总线高速数字IO的设计

CompactPCI／PCI总线是一种高速的，独立于CPU的总线结构，其本地总线接口逻辑的设计是应用CompactPCI／PCI总线开发高性能数字通信产品的难点所在。本文通过基于CompactPCI／PCI总线的高速数字IO的设计，详细分析了PCI9054本地总线接口控制逻辑，给出了接口电路的实现结构，并给出了最终的设计方案。     

基于FPGA的PCI总线接口设计

PCI是一种高性能的局部总线规范,可实现各种功能标准的PCI总线卡。随着总线技术的发展,PCI局部总线以其优异性价比和适应性成为大多数系统的主流总线。本文简要介绍了PCI总线的特点、信号与命令,提出了一种利用高速FPGA实现PCI总线接口的设计方案。     

USB2.0的激光光绘机接口系统设计

针对激光光绘机数据传输系统在PCI总线传输模式下难以维护与升级的缺陷,提出了一种新的基于USB2.0协议的激光光绘机接口技术.该技术充分利用了USB2.0高速的数据传输特性,将高速FPGA器件与USB控制芯片CY7C68013有机的结合,使激光光绘系统的使用更灵活、更方便,并有效地降低了设备的成本.介绍了系统的工作原理、硬件设计和相应的软件实现,并通过实验测量分析,证实该技术将完全能够取代PCI总线在激光光绘机接口系统中的应用.     

外围部件互连总线接口电路设计方案的研究

本文在研究PCI（Peripheral Component Interconnect）总线即外围部件互连总线的基础上，对采用专用接口芯片 CPLD和高速CPLD器件 PCI软件包的两种PCI总线接口设计方案。在性能，成本及设计复杂程度等方面进行了分析和比较，提出了一种采用S5933 CPLD实现通用高速PCI接口电路的设计方案。     

PXI总线接口技术研究

PXI总线是美国国家仪器公司于1997年9月1日发布的一种全新的、开放的模块化仪器标准总线.PCI 9030是PLX技术公司开发的PCI总线目标模块专用接口芯片,它完全符合PCI 2.2版规范,是业界首个支持CompactPCI热拔插的目标设备具有许多先进的特性.本文介绍其功能、特点,提出了采用PCI 9030+CPLD设计PXI总线接口电路的方法,应用PCI 9030完成基本的PCI总线接口,利用CPLD的可编程功能完成PXI总线接口逻辑控制.最后给出了在PXI总线开关模块中的应用实例.     

术语解释

PCIe： 全称为PCI—Express，是被广为采用的总线和接口标准，由英特尔公司在2001年提出，目前最新的PCIe标准为3．0版本。PCIe属于高速串行点对点双通道高带宽传输，所连接的设备分配独享通道带宽，不共享总线带宽，主要支持主动电源管理、     

基于PCI总线数据采集系统研究

本文主要讲述了基于PCI总线规范2．2的高速适时数据采集系统，32路外界信号经传感器转换成电信号输入A/D，转换后的数字信号通过总线接口设备PLX9030送到PCI总线。CPU处理过的数字信号又通过PLX9030送到局部总线，D／A转换后控制现场。     

数据采集系统的PCI总线接口设计

介绍了一种基于PCI总线的高速数据采集传输系统的实现方法。概述了快速、简易PCI总线控制专用芯片CH365的主要特点,描述了其本地硬件地址的实现方法,并给出了在12通道数据采集系统中的一个应用实例。     

基于PCI总线的激光粒度测量系统

本文设计了基于PCI总线的激光粒度测量系统,采用专用接口芯片S5933与CPLD相结合的方式实现PCI总线接口的设计,用CPLD开发了PCI数据采集的ADD-ON逻辑,通过DMA方式实现粒度测量系统数据由ADD-ON总线向PCI总线的传输,充分利用了PCI总线的高性能、高可靠性等特点,为激光粒度测量数据的实时采集、显示、处理提供了可靠的保证。     

基于AMBA总线的PCIE视音频处理卡设计

PCI Express总线高性能的数据吞吐率在高速数据处理系统中,特别是在高清视音频处理系统中获得了广泛的应用。为了增强图形、图像的处理能力,这类系统常带有帧缓存。如何设计高效的存储策略,让PCIE总线的高速、宽带性能得以充分实现,是DDR2＋PCIEFPGA方案设计中面临的一个关键问题。基于广泛使用的AMBA总线,很好的解决了多个（3个）非同步、高速数据源对DDR2存储设备的竞争性访问。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.