提高工业数字射线照相灵敏度的新途径

介绍工业数字射线照相提高钢焊缝中微小缺陷检测灵敏度的新途径：利用微焦点X射线源＋高灵敏探测器＋最佳投影放大率，能陵其IQI（像质计）灵敏度、影像对比度和空间分辨率，达到等价于甚至优于常规ISO T3类射线胶片的效果。     

工业射线照相影像质量评价

射线照相影像质量对保证工业射线无损探伤检测的可靠性和有效性具有重要意义。本文概述射线照相影像质量三要素一对比度，不清晰度和颗粒度的涵义，并重点介绍像质核心-射线照相三维灵敏度（对比灵敏度，细节灵敏度和裂纹灵敏度）的评价方法。本文分六个部分：1，概述，2，射线照相对比度；3，射线照相清晰度；4，颗粒性和颗粒度；5，信噪比；6、射线照相灵敏度。本期刊登其1和2两部分，其他部分将在以后各期陆续刊出。     

工业X-射线胶片射线特性检测方法的研究

工业Ｘ－射线胶片射线特性检测方法的研究阿尔梅感光化学公司（无锡２１４１６５）赵潭元曹进庆方志钧太原工业大学（太原０３００００）危昭才１．前言工业Ｘ－线胶片与其它常规卤化银胶片重要的差别在于工业Ｘ－线胶片直接记录Ｘ－射线（或γ射线）信息，而常规卤化银胶...     

外螺纹中径三针法测量技术研究

为适应公司生产形势的需要,在原测长机检测外螺纹中径的手段显得单一的基础上,在螺纹中径检测方法上拓出了一条新路。本文从螺纹中径检测入手,从测长机到立式光学计,重点阐明了立式光学计测量外螺纹中径的方法及可行性分析,最终得出了结论意见:立式光学计三针法测外螺纹中径的方法完全可以在生产中实施。     

不等厚对接管道焊缝射线检测技术探究

选用合适的透照工艺,能够显著提升射线检测的精准度,满足工程应用及相关领域技术标准的要求。对不等厚对接管道的焊缝进行射线检测,技术人员应该采用科学的管道焊接数字射线检测方法,在管道内采用X射线机进行焊缝的透射检测,技术人员应该控制透照厚度,并且根据射线编号和射线直径计算管道像质指数,及时发现对接管道内壁中存在的缺陷问题。本文从不等厚对接管道焊缝射线检测技术应用特点展开分析,提出几点有利于提升检测有效性的建议。     

一种四极质谱残余气体分析的实用方法

高真空系统残气分析对提高电真空器件的性能、质量和寿命具有重要作用。四极质 谱计与微机联用是必然的趋势。四极质谱计与微机联用是必然的趋势。四极质谱定性分 析是定量分析的基础。绝对灵敏度常数法和相对灵敏度常数法可以通过四极质谱计的灵 敏度定义相互联系起来。以相对灵敏度常数法为基础，将四极质谱计与电离真空计结合 起来，进行分压强和总压强测定的方案具有很高的灵敏度，能得到更好的重复性。     

射线数字成像检测系统不均匀性分析与校正

图像高低频畸变(即不均匀)会导致射线数字检测系统检测灵敏度的下降和误判,而造成畸变的原因是系统中射线源强度分布不均匀、闪烁体屏发光不均匀、镜头渐晕、科学级CCD暗电流和光响应不均匀。在此分析的基础上提出了一种校正方法,该方法利用实验得出校正矩阵,通过软件校正,先校正CCD暗电流和光响应不均匀性,再对其它三个因素合并校正。在便携式X射线源下,对三号透度计在15mm均匀钢板上的图像进行了校正实验,结果表明,灵敏度由校正前的1.67%提高到1.33%,图像不均匀性得到明显改善,空间分辨力大于3.5lp/mm。系统具有检测灵敏度高(≤1.5%)和适应射线能量范围大(50keV-15MeV)的优点。     

流程管理在漆包线线径检测中的应用

漆包线的线径是影响其电性能的一个重要参数。通过提出漆包线线径质量全流程管理的概念,设定了关键质量监控点位置的选择方式、全流程监控模式下的测试点三要素（数量、位置和时间）、监控策略的选择原则和转移规则,使漆包线线径检测设备具备动态调节能力,是漆包线线径在线、实时检测方法研究上的一个管理性创新。     

工业射线照相影像质量评价(续)--射线照相灵敏度

(续上期)6射线照相灵敏度射线检测工艺的核心是射线照相影像质量,而影像质量的核心就是射线照相灵敏度。所谓射线照相灵敏度,是指在射线照相底片上可发现的自然细节——主要是缺陷最小尺寸的能力。但自然缺陷灵敏度一般很难作准确评价,因为它与被检工件的形状、尺寸、性质、位置和相对于射线束的角度等因素有关。通常多用人为的“细节”——一定尺寸的丝、孔、槽,使其置于透照区最不利的位置,以其显示的最小尺寸来代表射线照相灵敏度,并建立尽可能符合实际的相关灵敏度公式作为评价或选定射线透照工艺参数的理论依据。由前述内容得知,射线照…     

工业射线照相的历史和发展

概述射线照相用于工业无损检测的早期历史,也回顾了近20年来工业射线照相的新发展。指出胶片法射线照相仍然是当前工业无损检测的主流。     

工业CR技术最新动态

概述工业计算机射线照相(CR)技术的最新进展,包括CR成像板荧光体结构的改进,信噪比和分辨率的提高,激光扫描器的多成像板同时输入、扫描和数字图像输出,使得对射线照相质量和灵敏度有较高要求、且对检测速度和周期也要兼顾的承压设备焊缝检测,有了稳定可靠的新基础。EN和ASME有关CR标准的推出,又为焊缝实施CR检测提供了法定技术依据。本文旨在为国内承压设备加速推广应用CR检测起推波助澜作用。     

Co—Fe—Si—B非晶丝的巨磁阻抗效应研究

用旋转水中纺丝法制成几种不同直径的（Ｃｏ０．９４Ｆｅ０．０６）７２．５Ｓｉ１２．５Ｂ１５非晶丝,对丝进行张力退火后,测试了非晶丝热处理前后的磁阻抗性能。结果表明制成的非晶丝具有明显的巨磁阻抗效应,且巨磁阻抗效应随电流频率不同而表现出正磁阻抗和负磁阻抗两种规律。张力退火对正磁阻抗效应有明显改善,而且对直径小的试样,阻抗对轴向外磁场变化的灵敏度更高。实验得到的最大灵敏度为１２４％／Ｏｅ。     

A comparative study of computer assisted assessment of image quality index for mammographic phantom images

Mammographic phantom images are usually used to study the quality of images obtained by dedicated mammographic equipment. The digital image treatment techniques allow us to carry out an automatic analysis of the phantom image. In this work, some techniques of digital image processing are applied to compute a specific image quality index (IQI) for a mammographic phantom, namely CIRS model 11A version SP01. The algorithm designed analyses the phantom image by means of automatic detection of the number of microcalcifications, and the image resolution as the number of line pairs per millimetre. Then, the IQI is calculated from a scoring system. The manner in which the functioning conditions (kV and mAs) of the mammographic equipment and the preprocessing denoising method of the digital image affect the results for the IQI are also studied.     

Transition to Quantum Turbulence Generated by Thin Vibrating Wires in Superfluid 4He

We report the turbulent transition in superfluid ⁴He generated by a vibrating wire as a function of its thickness. The response of a vibrating wire with a 3 μm diameter in superfluid ⁴He at 1.2 K reveals a hysteresis at the turbulent transition between an up sweep and a down sweep of driving force, while no hysteresis appears for wires with a thickness larger than 4.7 μm diameter. These results indicate that the 3 μm wire is efficient for reducing the number of vortex lines attached to it. A cover box and slow cooling also prevent vortex lines from attaching to a wire, resulting in a vortex-free vibrating wire. The effective mass of the vortex-free vibrating wire is almost constant in a wide range of velocities up to 400 mm/s; however, the wire density estimated from the resonance frequency is a half of the expected value of wire material, suggesting that a wire mass becomes lighter or a wire diameter becomes larger in the superfluid effectively.     

A simple approach for large-area fabrication of Ag nanorings

A simple and low-cost method based on a two-step heat treatment of AgNO(3)/SiO(2) film has been developed for fabricating metal Ag nanoring arrays. The as-prepared nanorings have an inner diameter of 70-250?nm and an average wall thickness (namely wire diameter) of approximately 30 nm with a number density of approximately 10(9)?cm(-2) on the surface of the SiO(2) matrix. X-ray diffraction (XRD) results reveal that these nanorings exhibit a face-centered cubic crystal structure. Furthermore, a new growth mechanism, namely a molten metal bubble as a self-template, is tentatively proposed for Ag nanorings.     

Irregular Characteristics of Bond Interface Formation in Ultrasonic Wire Wedge Bonding

The mechanism of ultrasonic wire wedge bonding, one of the die/chip interconnection methods, was investigated based on the characteristics of the ultrasonic wire bonding joints. The Al-1%Si wire of 25 μm in diameter was bonded on Au/Ni/Cu pad and the joint cross-section was analyzed by scanning electron microscopy （SEM） and energy-dispersive X-ray spectroscopy （EDX）. The results indicated that it is irregular for the ultrasonic bond formation, non-welded at the centre but joining well at the periphery, especially at the heel and toe of the joint. Furthermore, the diffusion and/or reaction at the cross-section interface are not clear at C-zone, while there exists a strip layer microstructure at P-zone, and the composition is 78.96 at. pct Al and 14.88 at. pct Ni, close to the Al3Ni intermetallic compound. All these observations are tentatively ascribed to the plastic flow enhanced by ultrasonic vibration and repeated cold deformation driving interdiffusion between AI and Ni at bond interface.     

铂丝位错特性对标准铂电阻温度计稳定性影响的研究

铂丝的位错是影响标准铂电阻温度计性能稳定性的重要因素之一。从微观角度出发,借助X射线衍射(XRD)分析方法,开展了退火时间对铂丝位错密度影响的研究,并利用标准铂电阻温度计退火实验数据进行了验证。结果表明:实际用于标准铂电阻温度计直径为0.07mm的新制铂丝(纯度99.999%)平均位错密度随着退火时间呈指数减小,经过100h退火后位错密度从1012cm^-2下降到1011cm^-2,300h后其位错密度基本保持稳定;新制标准铂电阻温度计在退火前300h其水三相点电阻值明显减小,退火300h后水三相点值变化量小于3mK并趋于平稳,此结果从热处理时间上与铂丝位错实验结果基本吻合。研究结果为标准铂电阻温度计制作工艺的提升及计量检定规程的修订提供技术支撑     

Effects of temperature distribution on plasticity in laser dieless drawing

Temperature measurement based on grey body radiation spectrum is used to determine the temperature profile of hot wires in the deformation region in laser dieless wire drawing, with spatial resolution down to a few micrometers. The Voce parameters characterizing the high temperature plastic flow behavior of the wires are calculated using the temperature and diameter profiles of the wires in the deformation region. These parameters are determined for as-drawn and annealed pure nickel wires of 500 m diameter. Recrystallization and grain growth during the drawing process are studied. The effects of temperature, grain size and precursor wire diameter on wire drawability and strain rate are analyzed. The measured temperature and diameter profiles agree well with theoretical results. Grain growth increases rapidly with increasing temperature after recrystallization, and the grain size follows the thermal activation law. The effective activation energy increases for larger wire diameter. Surface morphology of the drawn wires and strain rate calculation show that dislocation motion is the dominant deformation mechanism.