便携式位置探测仪信号接收装置电路设计

清管器在管道中运行时,其上的信号发射器发射出电磁脉冲信号,通过便携式位置探测仪上的信号接收装置接收信号,经过信号处理部分对信号进行解码、识别,最终将探测结果显示在液晶显示屏上。为了满足便携性的要求,探测仪采用低功耗设计,并大量使用贴片元件和功能集成的IC。经过深入的理论研究和测试,制造出了试验样机,该样机圆满地完成了多种环境下的试验,并取得了良好的效果。     

管道清管器电磁跟踪定位系统接收机的设计与实现

介绍了清管器电磁跟踪定位的基本原理。提出了清管器电磁跟踪定位系统接收机的总体方案。研制了低噪声、窄通频带、高精度数据采集电路,实现了微弱磁信号的准确检测。实测表明,所设计的清管器电磁跟踪定位系统接收机,有效跟踪范围可达10米,可以满足油气管道工程实际需求。     

行波磁场对电磁发射装置性能影响的实验研究

电磁发射装置中的行波磁场是推动射弹最重要的因素.为研究行波磁场对铝质射弹的作用规律,基于圆筒型直线感应电机的相关理论,研制了电磁发射装置样机.通过实验,系统地研究了行波磁场对电磁发射装置推进性能的影响.实验结果表明:随着外加三相电源频率或电压的升高,电磁推力增大、射弹的运动速度提高,与理论分析结果一致.     

舰载激光武器的研制进展

美国海军激光武器系统(LaWS)作为第1套海军的固体激光武器样机,已经安装在现役军舰庞塞号上.介绍了LaWS系统的应用需求、研制团队及系统结构,分析了激光器、发射装置及控制系统的构成,并由系统参量评估了LaWS系统的作战性能.回顾了LaWS系统已进行的系列演示试验,总结了每次试验暴露的技术问题及采取解决途径.由分析可知,LaWS系统的发射装置采用了天文望远镜的共孔径设计方式;作战光源采用了光纤激光器的非相干合成;在系统集成中,除了少量的定制部件外,广泛采用了工业激光器、惯性测量装置、传感器、视频跟踪器等大量商用器件;LaWS 系统在研制中采用了逐步改进的方式,这些都在一定程度上减少了系统风险和研制成本.最后分析了其下一步的技术发展方向.     

浅析ECM微波通道信号质量在设计和生产中的控制要素

目前ECM系统中,大多采用先将输入的射频信号下变频,再将中频存储后上变频并放大发射的体制。从ECM系统微波通道原理出发,定性分析了影响整个通道信号质量的主要因素变频本振、变频器隔离度、发射装置输入信号与发射装置之间的信号强度匹配以及通道的寄生信号,在此基础上提出了在ECM系统设计和生产过程中需要控制的要素。     

加固计算机的高功率微波防护

高功率微波武器(HPMW)由于波束宽,作用距离远,破坏性强,无需精密跟踪瞄准,所以HPM防护研究是一个既难又必要的课题。在研究高功率微波的性能特点、破坏过程以及破坏效应的基础上,从电源滤波、主板PCB设计、信号传输以及机箱屏蔽等方面给出了针对于加固计算机高功率微波防护的具体措施,并研制了试验样机。在样机的基础上针对性地进行了高功率微波辐照试验,并给出了样机的试验结果。     

双色探测激光引信抗海浪技术

阐述了双色激光引信探测的原理,提出采用双色探测,利用海水对红外激光与蓝绿激光回波特性时域差异显著,而舰船对二者的反射特性相近的特点,区分目标与海面,提出抗海浪干扰和判别目标的双色激光引信方案。双色激光引信利用激光发射系统同时发出红外和蓝绿窄脉冲激光,激光接收系统采用两路探测器分别接收两种波长的回波信号,信息处理系统对两路激光回波信号进行高速实时采集,获得两路回波信号幅度、脉冲宽度、回波率等区分目标和海面。通过设计样机并进行海面试验,试验结果表明,双色激光引信抗海浪干扰效果良好。     

基于分布式光纤振动传感系统的清管器跟踪定位

针对清管器跟踪定位设备无法实时连续跟踪的问题,将与油气管道伴行的通信光缆作为振动传感器,接入分布式光纤测振系统,实现清管器工作过程中的跟踪定位。清管器经过管道焊接缝隙时会发生撞击产生强烈振动波,通过采集和识别此种特殊的振动信号,经过时域和空域的分析,实现清管器实时跟踪定位。现场实验证明该技术可以有效进行清管器的实时跟踪定位,具有很高的工程应用价值。     

RASS声发射系统的设计

论述了某气象雷达为满足测量大气低层温度需要而设计的RASS声发射装置的工作原理和技术要点。声发射装置由音频信号产生器、音频功放和声天线三部分组成。     

一种智能温度控制器的设计

本文介绍了一种基于STC12C5620AD单片机控制的智能温度控制器,该系统通过控制SHT21传感器采集室内外的温度值,并通NRF24L01模块将数据传输至单片机,单片机通过控制红外发射装置发出控制信号来控制空调温度,避免人从室外至室内时,由于室内外温差过大,而引起不适甚至危害健康。     

基于RFID的生猪养殖监控系统研究

针对生猪管理的现状,本文提出将无线射频电子标识（RFID）技术应用于现代化的生猪养殖、屠宰加工环节。通过RFID耳标跟踪猪只的整个养殖流程,并把相应数据录入管理数据库,我们构建一套切实有效的RFID生猪养殖监控系统,从而实现对生猪养殖过程的统一管理。     

海底管道检测用线聚焦超声探头声场研究

海底管道缺陷的检测是由管道内智能猪完成的,智能猪上的超声探头阵列以恒定的速度一次性爬过管道,采集并记录缺陷数据供离线分析。所以探头的种类和性能直接影响对缺陷的检出率。论文针对智能猪用柱形曲面声透镜水浸式线聚焦探头,建立了其声场模型,并对其轴线声场和焦距进行了数值模拟。最后,实测了其轴线声场分布。     

Strength characterization of silicon microprobes inneurophysiological tissues

Experimentally determined strength characteristics of thin-silicon probes in neural tissues are discussed. It is shown that by proper selection of the substrate length, width, and thickness, silicon substrates can be designed and used to penetrate a variety of biological tissues without breakage or excessive dimpling. Thin-silicon structures have a maximum fracture stress which is a factor of six larger than that of bulk silicon and are very flexible and capable of bending to angles larger than 90°. Silicon substrates 15 μm thick×30 μm wide can easily penetrate guinea pig and rat pia arachnoid layers with minimum dimpling and no breakage, while substrates 30 μm thick×80 μm wide can penetrate guinea pig and rat dura mater repeatedly without breakage. Quantitative comparison on the relative toughness of neurophysiological tissues in rat and guinea pig have also been experimentally obtained     

基于激光诱导击穿光谱技术的生铁中硅锰钛偏析的同步分析

到目前为止,尚没有适用于大型金属材料试样元素偏析定量检测的有效方法。该研究将新兴的激光诱导击穿光谱（LIBS）技术应用于生铁中Si、Mn、Ti元素偏析的同步检测,选取Si（288.16 nm）、Mn（293.31 nm）和Ti（334.94 nm）作为三种元素的定量分析谱线,同时选取Fe（263.58 nm,441.51 nm,370.79 nm）分别作为三种元素的内标谱线,使用内标法降低基体效应的影响。定标拟合系数R2分别为0.991 7、0.990 3和0.991 2,因此证明LIBS适用于对生铁中Si、Mn、Ti元素的准确同步定量检测。随后将取自高炉的铁样切割为两个圆形的铁块,用空间分辨的LIBS装置对样品表面进行面扫描分析并得出元素分布图,基于元素分布图识别出Si、Mn、Ti元素的偏析区域并计算最大正偏析度和负偏析度。该研究证明了LIBS用于同步检测生铁中Si、Mn、Ti元素偏析的可行性,同时也揭示了生铁中合金元素的偏析规律,有利于加深对凝固过程元素迁移和分布的理解和认识。     

局部氧疗联合封闭负压引流干预促进豚鼠Ⅲ期压疮创面愈合的实验研究

目的：观察局部氧疗联合封闭负压引流干预促进豚鼠Ⅲ期压疮创面愈合的疗效,并优化其工作参数。方法：实验分疗效对比实验和参数优化实验两部分。疗效对比实验：选取20只清洁级雄性白色豚鼠,在左侧大转子处构建Ⅲ期压疮创面。20个创面随机分为五组：A组（持续-125mmHg负压治疗320min后给予5L／min的局部氧疗160min）、B组（-125mmHg负压治疗40min,5L／min的局部氧疗20min,交替8次）、C组（-125mmHg负压治疗40min后暂停20min,重复8次）、D组（5L／min的局部氧疗20min后暂停40min,重复8次）、E组（对照组）。在创面形成第0、1、3、7、11测量创面面积,计算创面面积收缩率。参数优化实验：构建23只Ⅲ期压疮豚鼠模型,采用均匀实验设计和多元回归分析,考察局部氧疗联合封闭负压引流干预方法的负压强度、氧流量、一小时内局部氧疗的工作时间和干预频次对日平均创面面积收缩率的影响。结果：在相同时相点,局部氧疗和封闭负压引流联合干预组创面面积收缩率均高于单纯负压、氧疗或空白组（P〈0．001）,且交替运行方式优于序贯运行方式。最优工作参数为干预频次12次／13、一小时内局部氧疗干预时间50min、封闭负压引流负压强度-125mmHg和局部氧疗氧流量10L／min。结论：局部氧疗和封闭负压引流联合干预方法能显著促进豚鼠Ⅲ期压疮创面愈合。均匀设计和回归模型可以对实验结果进行高精度预测,优化了工作参数。     

A video system for measuring motion in contracting heart cells

The design and characteristics of a video-based device that can noninvasively measure the extent and rate of shortening of isolated cardiac myocytes are discussed. Construction of the motion detector is relatively inexpensive. It is easy to use because edge selection is simple and the video images of contracting cells can be analyzed at the experimenter's convenience. The device also exhibits high spatial and adequate temporal resolution. The physiologic application of the motion detector was examined by measuring overall shortening in enzymatically dispersed adult guinea pig and rabbit cardiac myocytes bathed in Tyrode's solution containing 2.7 mm calcium at 36°C (pH₀ 7.4). When stimulated at 0.5 Hz, myocytes shortened an average of 8.1% (guinea pig) and 9.0% (rabbit) of cell length. respectively. The corresponding mean maximum rates of shortening were 81.7% (guinea pig) and 97.5% (rabbit) of cell length/s, respectively. The motion detector was also used to measure shortening between closely spaced markers on the cell surface     

Lumped-parameter model for in vivo cochlear stimulation

A lumped-parameter model that simulates the in vivo electrical properties of a guinea pig cochlea implanted with a multielectrode stimulating array is presented. A basic model of the low-frequency electroanatomy in a normally functioning guinea pig cochlea is developed by adding critical membrane capacitances to D. Strelioff's resistive network model (1973). The basic model of normal cochlear tissues is modified to account for anatomical and physiological differences between a normal and implanted cochlea, resulting in an impedance model of an implanted cochlea. Simulating the results of in vivo cochlear stimulation verifies the accuracy with which the modified cochlear model represents electrical properties within an electrically stimulated cochlea. Generalized simulations using this model suggest a straightforward phasing scheme capable of achieving sharply focused, channel-independent multielectrode cochlear stimulation     

A Method for the Exposure of Miniature Swine to Vertical 60 Hz Electric Fields

A Plexiglas enclosure was built to hold Hanford miniature swine for exposure to vertical 60 Hz, single-phase electric fields; water was provided through a grounded metal drinking nozzle. The field at the top of a pig's back was increased over the field in the empty enclosure by a factor of 7. A pig's impedance to ground, while standing on a grounded metal plate, was about 2-3 kohms. The average normalized short circuit current for four swine was 6.8 ?A/(kV/m). All of the swine were able to drink with no evidence of shocks at the maximum attainable unperturbed field strength of 55 kV/m. The current between the grounded nozzle and the drinking pig was 1-3 ?A/(kV/m). The threshold of perception of a mouth-to-nozzle current averaged 275 AA. Two swine exhibited ear flicking above 50 k/m, and visible hair motion was observed on the ear of one anesthetized pig at fields larger than 40 kV/m. A behavioral test suggested that swine were able to perceive fields greater than 30 kV/m. Photographic tests detected no corona discharge from an anesthetized pig or the test enclosure.     

Design of an integrated sensor for in vivo simultaneous electrocontractile cardiac mapping

While there is extensive mapping of the spread of electrical activity in the heart, there have been no measurements of electrical and localized mechanical, or contractile, activity. Yet the development of effective treatments for diseases like chronic heart failure and cardiac hypertrophy depend on the ability to quantify improvements in electrocontractile function. In this paper, we present a sensor that is capable of making simultaneous, electrocontractile measurements. Its small size facilitates placement in multiple myocardial sites for multichannel studies. Semiconductor strain gages are used for force sensing, and Ag/AgCl-plated tungsten electrodes act as electrogram sensors. The sensor contains electronics on-board, including instrumentation amplifiers and a microprocessor for data sampling and analog-to-digital conversion. Each sensor can accurately detect 0-245+/-5 mV in two electrogram channels with a sensitivity of 0.96+/-0.2 mV/step and less than 2% error, and 0-144+/-29 g of contractile force with a sensitivity of 0.56+/-0.11 g/step in the analog-to-digital conversion and less than 6% error. The sensor has been tested in vivo in open-chest rabbit and pig mapping studies. These studies indicated that the average peak-to-peak contractile force at the apex is smaller in the rabbit than the pig (13.3 versus 40.3 g), that the average peak-to-peak contractile force in the pig is smaller near the base than near the apex (31.3 versus 40.3 g), and that contractile force is visibly decreased during ventricular fibrillation compared to normal sinus rhythm.     

清管器(Pig)清洗技术

文章对清管器的结构。性能、应用特点进行了全面分析,并对它在输水管、输油管及工业管线清洗中的应用情况做了具体介绍