FPGA原理及其在石油勘探仪器中的应用

随着可编程逻辑器件的发展,FPGA的应用已经越来越广泛,且用可编程逻辑器件代替传统的普通集成电路已成为一种发展的趋势。可编程逻辑器件FPGA以其高集成度、高速度、开发周期短、稳定性好而受到了人们的青睐,并得到了广泛的应用。文章介绍了FPGA的原理及实现技术,并阐述了其在石油勘探仪器中的具体应用。     

408UL仪器与KZ-28震源配套助理软件的设计编程和应用

在实际生产中,经常需要408 UL仪器与KZ-28可控震源ADVⅢ箱体配合施工,但由于这两种设备不兼容,导致了408 UL仪器记录系统产生的单炮文件号与KZ-28震源ADVⅢ箱体系统产生的该炮记录相应的振动编号匹配不上,影响了对单炮记录激发因素指标的分析,不利于后期施工方案的设计。本文介绍的软件可以准确地把单炮记录的文件号、炮点桩号等数据与震源激发产生该记录相应的振动编号、坐标等数据对应起来,最后生成Ex-cel表。该软件具有操作简单、实用性强、结果准确、便于统计等特点,文中主要对该软件的设计思路和编程原理进行了介绍。     

408UL仪器地面站单元电路原理

408UL仪器是目前国内外的主流勘探仪器，本文从408UL采集站、交叉站、电源站的组成和功能着手，详细介绍了408UL地面站单元的工作原理，并阐述了408UL野外数据采集的流程。     

408UL仪器LAUX±24V电源电路原理分析

LAUX作为CM408和野外排列连接的接口,在408UL仪器整个数据链路中起着关键作用.鉴于LAUX硬件故障多数出现在电源电路上,本文根据LAUX实物绘出了它的土24V电源电路原理图,并对该部分电路的工作原理进行了深入分析.     

多套采集系统在高精度二维可控震源施工中的应用

物探工作对数据采集系统的接收能力提出了越来越高的要求,使用多套采集系统进行同步采集施工不失为一种经济、便捷的方法.本文结合实际,重点介绍了使用两套408UL地震仪器系统通过VE432震源控制器进行主从同步采集的施工方案.     

UL796印制线路板安全标准介绍

本文介绍了最新版本UL796《印制线路板》安全标准涉及的主要内容、章节与概要,所作的修订及其特点。     

Synthesis,flame‐retardancy testing,and preliminary mechanism studies of nonhalogenated aromatic boronic acids: A new class of condensed‐phase polymer flame‐retardant additives for acrylonitrile–butadiene–styrene and polycarbonate

This study describes the syntheses and thermal properties of aromatic boronic acids and their use as flame retardants. The possible flame‐retardancy mechanisms are also discussed. The materials were synthesized from aromatic bromides using one of two procedures. The first procedure involved traditional approaches to boronic acids, using lithium–halogen exchange and quenching with trimethylborate followed by hydrolysis. The second procedure used a nickel catalyst and a dialkoxy borane to generate aromatic dialkoxyboronates that were converted to boronic acids by acid hydrolysis. The thermal properties of these aromatic boronic acids were studied using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). These materials were blended into acrylonitrile–butadiene–styrene (ABS) and polycarbonate (PC) resins and tested for ignition resistance, using the UL‐94 flame test. A 10 wt % loading of 1,4‐benzenediboronic acid in polycarbonate gave a UL‐94 V‐0 result. This same diboronic acid showed flame retardancy and char formation in ABS, but this result was not quantifiable by the UL‐94 test. Burn times for the ABS samples often exceeded 5 min, thereby showing unusual resistance to consumption by fire. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1257–1268, 2000     

Full Scale Burn Tests of Television Sets and Electronic Appliances

Ten full-scale burn tests of television sets and electronic appliances were performed to: (1) demonstrate the ignition propensity and fire performance characteristics of materials used in the construction of television sets marketed in the United States and to compare these to the fire performance of television sets marketed in Europe; (2) document the damage to television sets when exposed to nearby burning materials; (3) evaluate and compare the damage to television sets when subjected to different size, duration and types of fires; (4) evaluate fire damage to television sets and electronic appliances when exposed to post flashover conditions; and (5) evaluate electrical damage caused to components of electronic appliances while they are powered and subjected to exposure fires.Ignitability tests showed that television sets constructed with cabinets made of V-0 rated plastics (for the U.S. market) will not ignite and propagate a flame under the test conditions. Television sets made of HB rated plastics (for the European market) will ignite and propagate a flame under the same test conditions and the television set will be consumed in the ensuing fire. The UL 94 tests do not provide rate of heat release data; however, calorimetry test data showed that the rate of heat release and the burning of the electronic appliances and television sets were in part dependent on the size of the exposure fire.Examination of the television sets and electronic appliances after the burn tests showed that the severity of damage and type of damage varied significantly. Electrical fault activity was noted to have occurred both exterior and interior to the powered television sets as well as other powered electronic appliances. In all cases, the fire source was external to the appliance.Post fire examination after the flashover fires showed that fire pattern analysis and burn damage are not necessarily indicative of the area of origin or cause and can be misleading to even experienced fire investigators.     

逻辑系统UL的广义H-赋值

研究了Schweizer-Sklar T-范数（本文讨论p〈0的情况）及其刺佘蕴涵的性质。以此为基础,对泛逻辑基本形式系统UL中的H-g值进行了拓广,引入了广义H-赋值概念,证明了UL在广义H-赋值之下可靠性定理成立。     

Load/unload measurements using laser doppler vibrometry and acoustic emission

The dynamics of the load/unload process are studied using a so-called ‘periscope approach’ which allows us to follow the slider motion during load/unload (L/UL) with the beam of a Laser Doppler Vibrometer (LDV). LDV signals and acoustic emission signals are obtained for three different slider airbearing designs and for load/unload conditions with different vertical velocities and spindle speeds. The load process is investigated statistically using the acoustic emission signal in order to determine the effect of vertical load speed and spindle speed on the probability of contacts between slider and disk.The results indicate that small vertical load speeds decrease the number of head/disk contacts, and that slider designs with a cavity centered close to the trailing edge enable a smooth unloading process.