Study of ultrasonic phased array inspection imaging technology for NDT

0Introduction Ultrasonic testing (UT) is one of most common NDTtechniques in detecting discontinuities in structures duringmanufacturing and in service. A conventional transducerwith a single piezoelectric element has a fixed radiationfield in a given specimen, hence the focal depth and theangle of incidence could not be changed. In ultrasonicNDT, it is quite often necessary not only to change the an-gle of incidence of ultrasonic wave to cover given inspec-tion area but also to focus the i…     

水套炉盘管泄漏的原因分析

本文通过对一台水套炉盘管泄漏的原因分析,对油田管理水套炉提供参考建议,对减少水套炉事故有一定的意义。     

测绘信息管理系统混合编程应用技术

以我院开发的广州市黄埔区三级土地信息发布平台系统和广州市控制测量成果子系统中与数据库和应用程序之间的混合编程技术为例子、阐述了利用地理信息技术对测绘数据和资料进行科学、统一管理的方法。     

结合故障相关的软件构件NHPP可靠性模型研究

传统的NHPP类模型是评价软件可靠性的重要模型之一。通过将故障关联融入到NHPP模型中,改进了传统的GO模型。并分析了时间域模型和基于构件模型的不足,提出一种结合两种模型的方法,同时考虑了故障排除和软件体系的方面的问题,使软件可靠性模型更加接近于实际的软件系统。     

Impact fracture morphology of nylon 6 toughened with a maleated polyethylene–octene elastomer

This study aimed at using scanning electron microscopy to study the Izod impact fracture surface morphology of super‐tough nylon 6 blends prepared by blending nylon 6 with a maleic anhydride‐grafted polyethylene‐octene elastomer (POE) in the presence of a multifunctional epoxy resin (CE‐96) as compatibilizer. The fracture surface morphology and the impact strength of the nylon 6 blends were well correlated. The fracture surface morphology could be divided into a slow‐crack‐growth region and a fast‐crack‐growth region. Under low magnification, the fractured surface morphologies of the low‐impact‐strength nylon 6 blends appeared to be featureless. The area of the slow‐crack‐growth region was small. There were numerous featherlike geometric figures in the fast crack growth region. The fractured surface morphologies of the high‐impact‐strength nylon 6 blends exhibited a much larger area in the slow‐crack‐growth region and parabola markings in the fast‐growth region. Under high magnification, some rubber particles of the low‐impact‐strength nylon 6 blends showed limited cavitation in the slow‐crack‐growth region and featherlike markings in the fast‐crack‐growth region. Rubber particles of high‐impact‐strength nylon 6 blends experienced intensive cavitation in the slow‐crack‐growth region and both cavitation and matrix shear yielding in the fast‐crack‐growth region, allowing the blends to dissipate a significant amount of impact energy. A nylon 6 blend containing 30 wt % POEgMA exhibited shear yielding and a great amount of plastic flow of the matrix throughout the entire slow‐crack‐growth region, thus showing the highest impact strength. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1285–1295, 2000     

中国古代织金丝织物织造方法初探

通过对中国古代织金织物的分析,发现织金的方法有各种差异:a)金纬有通梭织入与挖梭织入的不同;b)对金纬的接结有地结与特结的不同;c)地纬与金纬有全越排列和半越排列的差异,各种方法都备有特点及自身发生、发展的历史。中国古代织金织造方法以挖梭、地结、全越为起始,随着通梭、特结、半越等方式的出现,它们即相互结合,共同构成了绚丽多姿的中国织金艺术。     

改进型先验信噪比估计语音增强算法

在DCT域提出了一种改进STNR(M-STNR)算法,其在原算法的第二步中利用信号的高斯模型假设条件,采用MMSE估计来获取当前帧先验信噪比的估计,算法无需语音增强系统增益因子的任何先验条件,在保持简单结构的同时避免了原算法的不足。仿真结果表明,基于该改进方案的语音增强算法在多种噪声背景下具有更出色的语音增强效果。     

人体高原适应性多参数同步监测系统

针对急性高原反应,研发了相关的人体高原适应性多参数同步监测系统。通过无创的方法来监测人体在高海拔环境下相关生理参数（血氧饱和度、心率、心电、脉搏波、呼吸）的变化,同时监测人体所处外界环境参数（海拔、气压、温度、方向、GPS定位）。通过基于无创多参数同步测量系统之上的高原适应性分析算法,对多种参数综合分析,给出人体在高海拔下的高原适应状况的直观判断,通过通讯模块实现数据远距离无线传输。     

抗震结构模糊随机动力可靠性分析

本文对在考虑地震烈度和场地土分类的模糊性的基础上所建立的含模糊参数的地震地面运动随机过程模型,采用分步等效线性化及状态方程法,求出了结构模糊随机变形和能量反应的统计矩;基于单参数(变形或能量)及双参数(变形和能量)的模糊破坏准则,分析了抗震结构的模糊随机动力可靠性。最后给出了两个自由度结构的数值算例,表明双参数准则更为合理和安全。