图像分辨率测试卡的结构与标准

分辨率测试卡是客观描述射线实时成像检测系统分辨率和实时成像检测图像分辨率（包括射线照相底片分辨率）质量指标的重要器具，概述了图像分辨率测试卡的结构和正在制订的《无损检测射线透视检测用分辨率测试卡》行业标准进展情况。     

小径管自动X射线实时数字成像检测系统设计

比较和分析了各种小径管对接焊缝X射线实时成像技术,开发出一种性价比极高的自动X射线实时数字成像检测方法和设备。实际应用的结果表明,系统具有检测速度快、灵敏度和分辨率高的特点,成像质量优于JB 4730—2005标准中规定的AB级。     

基于CMOS探测器的环焊缝检测系统设计

针对常规X射线照相检测技术检测环焊缝时工作效率低的问题,结合数字成像技术的发展,利用空间分辨率较高的CMOS成像面板,拆除成像板中的扫描驱动机构,重新设计检测系统,对环焊缝进行数字化扫描检测,从而快速、高质量地完成环焊缝的射线检测工作。     

金属缺陷的分辨率研究

根据微小焦点X射线成像检测的基本原理,建立系统点扩展函数模型,并推导出检测系统的分辨率关系,最佳放大倍数以及最小检测缺陷公式。对成像检测具有指导作用。并给出在金属缺陷检测中的实际应用。     

X射线实时成像系统分辨率及其影响因素

概述了X射线实时成像系统的基本配置和反映系统质量特性的调制传递函数以及提高X射线实时成像系统分辨率的基本方法。     

曝光参数对X射线数字成像系统图像质量的影响

通过设计正交试验,分析了X射线数字成像(DR)系统中曝光参数对图像对比度和分辨率的影响,讨论了曝光参数对DR检测系统图像质量的影响,为该DR检测系统曝光曲线的制作提供了数据支持。结果表明,选择较低能量的X射线可以提高衰减系数,从而提高图像对比度。     

分辨率测试卡的结构及图像分辨率测试方法

分辨率是X射线实时成像检测图像质量的重要指标之一，概述了分辨率测试卡的结构及图像分辨率的测试方法。     

实时成像技术在钎焊蜂窝结构检测上的应用

介绍了金属蜂窝钎焊件生产制造过程中的实时成像检测。传统射线照相技术受限于管径及射线束角度,透照有效区域小,大型蜂窝结构件检测效率低;同时还会发生由于工件厚度变化致使芯格影像变形的问题,影响检测结果的判断。运用实时成像技术对蜂窝结构件移动扫描检测,有效地解决了上述问题,同时使用分辨率测试卡,保障了系统的分辨力,获得了满意结果。     

数字射线检测实用指导(一)——射线检测系统的分类

随着数字化技术的不断发展,各类射线数字成像检测技术的应用已成为发展的趋势。为使无损检测人员更加系统地了解和掌握各类射线检测系统,并能针对不同的检测对象、不同的应用场合等特定条件,按照各类射线检测系统的不同结构、成像机理等合理地选择射线检测系统。对目前市场上不同的射线检测系统进行了归纳、分类,如按照成像结果分为模拟成像和数字成像;按照检测系统与被检工件的运动状态分为静态成像和动态成像等。最后就DR数字成像检测系统的组成、原理、相较于胶片照相的特点及其成像技术分类进行了概述。     

射线实时成像检测中的图像清晰度与分辨率

清晰度与分辨率是X射线实时成像检测中的重要质量特性，分析检测图像的清晰度与分辨率问题及相互关系，介绍分辨率测试卡结构和使用方法以及提高图像分辨率的途径。     

Study of ultrasonic phased array inspection imaging technology for NDT

A research about the ultrasonic phased array imaging principle from A-scan signal to B-scan image for non-destructive testing （NDT） was conducted in this paper, the ultrasonic phased array inspection imaging system used in industrial field was developed and the experiment was performed on the steel testing block by the system with 64 elements, 5 MHz phased array transducer. Experimental results show that the flaws could be accurately detected and the flaws size could be estimated from the B-scan images, and the B-scan images could clearly show the location of the flaws, but the quality of B-scan images needs to be enhanced by digital signal processing and controlling dynamic focusing for improving the image resolution.     

图像增强器式线阵列X射线数字成像系统

针对现有线阵列X射线数字成像技术的设计原理和存在的不足,利用图像增强器和图像传感器的最新技术成果,研制成功新型线扫描成像系统。该系统在检测速度为6m／min的条件下,最高分辨率可达10．0Lp／mm,IQI灵敏度1．25～1．60％,图像质量满足JB／T4730-2005标准AB级要求。系统可广泛应用于锅炉压力容器和压力管道焊缝及铸造零件的内部缺陷检测。     

基于波束仿真的合成孔径聚焦成像研究

超声成像检测技术在现代工业无损检测中具有重要地位,已成为定量检测的重要手段。提高分辨率是目前超声成像的发展方向,成像分辨率是评价超声成像系统的重要的性能指标之一。但超声波在被检测物体中传播时,探测的深度与获得高分辨率是一对固有的矛盾,即高频超声系统的分辨率高但穿透深度浅,低频超声系统的分辨率低但其穿透深度深。通过对合成孔径的成像原理、成像算法、方位分辨率等问题的分析,从理论上论证了合成孔径成像的分辨率只和孔径的大小有关,而和脉冲频率的高低没有关系,阐述了应用合成孔径技术在超声波无损探伤系统的可行性。通过Matlab对单阵元合成孔径聚焦波束和多阵元合成孔径聚焦波束进行了仿真,为今后的实际应用提供了依据。     

TFT面阵探测器X射线数字透射成像

通过对裂纹模拟缺陷试件的数字透射成像检测试验,分析并研究了面阵探测器成像检测系统、透照参数、检测工艺与检测图像质量的关系,并给出了检测过程中应该注意的问题。具体试验表明：面阵探测器X射线数字成像系统在一定厚度范围内的检测效果（主要是图像的单丝像质计指数）优于同厚度的射线照相B级要求。     

Magnetooptical sensors using in-plane biased garnet films supporting domains

Rare-earth iron garnet films are currently used as magnetooptical indicator films for visualization of magnetic leakage fields in nondestructive testing. For gray scale imaging in-plane magnetized films are used yielding a high spatial resolution. On the other hand, garnet films supporting magnetic domains can be prepared having a very high sensitivity, while their resolution is limited by the size of the domains. This behavior can be improved considerably by applying a bias induction B in the plane of the sensor film. Just above the collapse-induction B_,coll the in-plane magnetized film offers a high spatial resolution with still high sensitivity. Experiments demonstrate a clear improvement of the quality of the magnetooptical imaging. The experimental results are in agreement with calculations.     

Nanoscale femtosecond spectroscopy for material science and nanotechnology

The design and implementation of a novel facility to perform ultrafast spectroscopy and three-dimensional (3D) fabrication at the nanoscale is reported. Single and multiphoton femtosecond excitation coupled to a laser scanning confocal microscope and a photon counting streak camera system allows to perform photoluminescence (PL) spectroscopy with in-plane spatial resolution of the order of 100 nm and temporal resolution of ∼2 ps. The facility combines high performance imaging capabilities in 3D with high sensitivity detection system and time-resolution of the photoluminescence. Imaging and spectroscopy are performed on the same spatial position thus allowing a direct correlation of the morphological features with the spectroscopic properties. The use of a laser scanning confocal microscope gives the advantages of far-field microscopy (possible sample perturbation as in the case of near-field technique is prevented) with spatial resolution well below the diffraction limit, and fast laser scanning for fast data acquisition and lower sample photodegradation. A possible application of this optical nano-probe is in the spectroscopic investigation and imaging of the active areas of molecular electronic and optoelectronic devices, such as TFTs, LEDs and PVs cells. The morphology of active layers within working devices can be correlated to field distributions, charge flows, charge recombination and light emission. We show the potential of this novel experimental set-up for the study of organic, hybrid, biological nanostructures and nanodevices.     

上海光源X射线成像及其在材料科学上的应用研究进展

上海光源是第三代同步辐射光源,其X射线成像具有高空间分辨、快时间分辨、高衬度分辨的特点,可对材料样品实现原位、无损、高分辨、三维和动态成像,利用同步辐射光源的高度相干性可以实现相位衬度成像,从而可以实现聚合物等低Z材料的高衬度X射线成像,而传统的X射线吸收衬度成像在对轻元素材料成像上获得的衬度极低。为更好地支持用户,基于上海光源X射线成像线站,建立和发展了定量相衬成像、动态CT成像、基于多种衬度机制的CT成像、快速CT重构等成像方法。本文简要介绍了上海光源X射线成像方法学发展及其在材料科学上的应用研究进展。     

磁共振成像超导接收线圈品质因数的实验研究

射频接收线圈是磁共振成像系统中的重要部件,主要针对超导接收线圈的品质因数进行实验研究,并给出了测试原理和方法。使用一种双探测线圈法对Bi2223/Ag超导带材制作的接收线圈在室温和液氮温度下的品质因数进行了测试,并与铜制谐振回路的测试结果进行对比分析。结果表明,在77K下超导接收线圈比室温下铜线圈的品质因数高约两倍。这说明使用超导材料制作射频接收线圈,可有效提高谐振回路的品质因数,从而进一步改善磁共振成像系统的信噪比及成像质量。     

Non-destructive thermal-wave-radar imaging of manufactured green powder metallurgy compact flaws (cracks)

Thermal wave radar imaging (TWRI) was developed to detect manufacturing cracks in automotive powder metallurgy components (transmission sprockets) in their green (unsintered) state. The crack detection capability of the TWRI phase was validated by two sets of cracked/crack-free green and sintered sprockets which were sectioned after TWRI measurements. An automatic defect recognition (ADR) TWR image processing method was also developed to differentiate cracks from local defects. Measurement results demonstrated that TWRI is superior to conventional lock-in thermography imaging (LITI) in both flaw detection resolution and speed, and thus is a viable green-sprocket manufacturing flaw imaging technology.