南海一号出水景德镇窑与龙泉窑青瓷特征的无损分析研究

古代陶瓷产地研究是陶瓷考古的重要内容,也是科技考古工作者研究的重点。目前国内古代陶瓷产地研究主要依赖化学成分分析技术,对陶瓷釉层结构特征的无损分析研究却相对缺乏,难以对古代陶瓷进行全方位的认知。该研究首次将光学相干层析(OCT)与X射线荧光(XRF)光谱分析技术相结合,对南海一号沉船出水的南宋初期景德镇窑和龙泉窑青瓷瓷釉的断层结构特征和化学成分特征进行综合无损分析研究。首先采用扫频OCT成像系统对两个窑址青瓷瓷釉断层结构及装饰工艺特征进行了研究,分析了青瓷瓷釉类型、釉层厚度、釉层内气泡、包裹体、表面裂纹等特征及分布状况,对比了两窑址青瓷瓷釉断层结构特征,确定了可能采用的装饰工艺。其次,利用X射线荧光(XRF)光谱分析获得了两窑址青瓷胎釉的化学成分,对比研究了两个窑址青瓷胎釉化学成分差异,进而探讨了瓷釉断层OCT图像特征与釉层化学成分之间存在的联系。实验结果表明,景德镇青瓷和龙泉青瓷样品在釉层厚度、气泡、裂纹、包裹体等瓷釉断层结构特征上差异明显,在胎釉化学成分方面,两类青瓷在胎釉着色相关元素、釉层碱性氧化物等成分含量上也存在差异。同时,瓷釉断面结构特征差异与釉层化学成分差异存在紧密联系。实验证明,将OCT与XRF相结合是一种有效的辨别瓷器窑口的科学技术方法。     

河南省清凉寺窑址出土富铁釉瓷的无损分析研究

富铁釉瓷在中国古陶瓷史上具有重要地位，综合利用光学相干层析成像技术(OCT)、光学显微镜(OM)、激光拉曼光谱技术(LRS)和X射线荧光光谱分析技术(XRF) 对河南省宝丰清凉寺窑址出土宋金时期富铁釉瓷样品进行无损分析研究，获取了富铁釉瓷的釉层结构、釉面析晶的物相信息及胎釉化学成分等信息，探讨了釉层断面OCT灰度图像特征与其显微结构之间的关系以及富铁釉瓷的烧制工艺。结果表明，酱釉瓷和柿叶红釉瓷表面及黑釉红斑区存在富铁析晶层，黑釉瓷釉层表面未发现富铁析晶层的存在。酱釉瓷釉层富铁析晶层中铁的氧化物以ε-Fe₂O₃晶体为主，而柿叶红釉层则主要是α-Fe₂O₃晶体，黑釉红斑层同时存在ε-Fe₂O₃，α-Fe₂O₃晶体以及磁铁矿。上述差异形成的原因与釉层化学成和烧制工艺存在联系。釉层中高含量碱土金属氧化物及氧化铁区域更容易析出氧化铁晶体。黑釉瓷烧成气氛以还原气氛为主，而酱釉瓷和柿叶红釉瓷则倾向于氧化烧成气氛，且柿叶红釉瓷的烧成温度高于酱釉瓷。该研究将OCT，OM，LRS与XRF相结合，有助于加强对富铁釉瓷的整体认知，为富铁釉瓷的断源断代提供更为丰富的线索。     

巩窑唐代早期白瓷的EDXRF线扫描分析

具有悠久瓷器生产历史的巩窑,是我国古代北方烧制白瓷的3个代表性窑口之一。在唐代早期,为了掩盖瓷胎表面的粗糙状态和较深的胎体颜色,提高瓷器的质量和白度,巩窑白瓷在胎的表面施加了一层装饰层——化妆土。用能量色散X射线探针技术对这些白瓷碎片的剖面进行了主要化学成分的线扫描分析,结果表明： 巩窑唐代早期白瓷的化妆土使用了不同的原料,与光学显微镜下观察到的现象相符合。另外,白瓷釉可能是加有草木灰的钙釉。     

基于卷积神经网络的古陶瓷窑口甄别

古陶瓷作为中华文化的瑰宝,自古以来不仅在国内受到追捧,在国外同样被视若珍宝。伴随着古代商贸的进行,中国古陶瓷遍布全球各地,辗转流传被私人或博物馆收藏,还有部分古陶瓷经墓葬发掘以及沉船打捞后被收藏于博物馆,这类古陶瓷的产地溯源一直以来都是陶瓷考古的重点,对于研究古代商贸和文化交流有重要的意义。通过便携式数码显微镜、分光光度计、 X射线荧光等方法对从越窑后司岙、越窑寺龙口、龙泉枫洞岩窑、耀州窑发掘出土的青釉瓷样品进行分析测量,获得了来自四个窑青釉瓷样品的微观气泡尺寸分布特征、紫外可见近红外光谱特征、釉的成分数据。将来自四个窑青釉瓷样品的这三种特征作为变量建立卷积神经网络分类模型进行训练和验证,结果表明青釉瓷的微观气泡尺寸分布特征、紫外可见近红外光谱特征以及瓷釉成分数据均有效,但是不同特征的分类准确率差异非常明显。三十次随机划分训练集与测试集的模型训练平均准确率：微观气泡尺寸分布特征模型为75%,紫外可见近红外光谱特征模型为89.2%,成分数据模型为92.1%,成分数据模型准确率最高且训练集与测试集准确率相差最小。将基于不同特征训练好的模型参数保存进行融合后再训练发现基于紫外可见近红外光谱特...     

OCT系统对人体牙齿组织的非失真成像深度的研究

利用基于蒙特卡罗方法的牙组织光学相干层析(OCT)成像模型,研究了不同牙组织的OCT非失真成像深度。通过模拟入射高斯光束以及光在牙组织中的传输,分别获得了单层牙釉质、单层牙本质以及两层牙组织结构的二维仿真OCT图像,与实验结果具有定性的一致性。通过分析二维仿真OCT图像所对应的一维OCT信号,分别得到了三种牙组织结构的平均非失真成像光学深度。研究结果表明,OCT系统对牙齿组织的非失真成像光学深度在150~2400μm之间,其中牙釉质的非失真成像深度要远大于牙本质的成像深度。所得的结果对于在实验中利用OCT图像对组织结构有效信息进行判断具有一定的参考价值。     

景德镇官窑紫金釉组成及呈色特征

颜色釉是景德镇四大传统名瓷之一,明清时期官窑颜色釉更是其中的杰出代表,蕴含着丰富的科技和文化内涵。采用能量色散X荧光仪和色差计,首次较为系统地分析了景德镇明清官窑紫金釉瓷的胎、釉化学组成和色度值,初步探讨了不同时期官窑紫金釉的组成、配方和呈色特征,及其内在原因。研究表明,紫金釉中钙、镁含量不同于景德镇同时期其他釉种,应刻意选用了镁含量较高的赤褐色或褐色石灰石炼制釉灰入釉;明代紫金釉中镁、铁含量高于清代样品,导致其釉层表面富铁晶体的析出,降低了釉面的明度和光泽度,这也是景德镇明代官窑紫金釉外观呈色更为深沉古朴的主要原因。此外,景德镇明清时期官窑紫金釉瓷胎组成具有"高硅低铝"的特征,且从明代至清代SiO2/Al2O3摩尔比呈下降趋势,表明清代紫金釉制品胎体中高岭土的添加比例有所提高。实验结果填补了我国陶瓷科技发展史研究中关于景德镇明清官窑紫金釉部分的不足,为全面认识景德镇官窑制瓷技术和内涵价值提供了一定的科学素材。     

正向切片光学相干断层成像系统的信号提取方法

光学相干断层成像(OCT)技术因非入侵、非接触特点和断层成像能力,在眼科、血管内窥等临床医学与药物学中有广泛应用。OCT发展至今,根据成像方向的优先次序,产生了两类技术分支。一类是沿光束入射方向逐线(A-line)扫描的标准型OCT,可生成基于纵向断面扫描(B scan)的图像,常用于眼底组织的层析成像;另一类en-face OCT,也叫正向切片OCT,可在与入射光垂直的方向上生成样品层的横向切片图像,且以显微成像方式来显示生物组织的精细结构,大大丰富了OCT的图像采集与呈现方式。en-face OCT系统可采用不同的信号采集方式,在对其分析和归纳的基础上,对该技术的主要发展方向作了展望。     

陕西周原遗址出土西周原始瓷工艺特征的初步研究

南方地区原始瓷出土数量较多且出土地点较为集中,从而对它的工艺和产地研究较为深入;而北方原始瓷因出土地点分布零散和数量的限制,对它的科技分析比较少。随着陕西周原遗址出土了大量原始瓷,有必要对该遗址出土的原始瓷做一个整体分析。为了探讨陕西周原遗址出土西周时期原始瓷的工艺特征,采用超景深三维视频显微系统和能量色散X射线荧光光谱分别对原始瓷胎釉微观结构和化学元素组成进行了观察与测试。显微观察可见：原始瓷胎质粗糙,胎中未熔颗粒、孔隙较多;施釉不均,釉层较为浑浊,分布较多气泡。化学组成测试结果显示：胎中Al₂O₃含量集中在11.8%～17.21%,SiO₂含量分布在75%～80.5%, K₂O含量分布在3%～7.85%;釉中CaO含量分布在11.08%～23.94%, P₂O₅含量分布在1%～3.18%、MnO含量分布在0.24%～1%,而釉中P₂O₅,MnO,K₂O含量较胎相对提高。结果分析表明：原始瓷胎料可能选用含较高钾的瓷石;釉应是添加了草木灰的钙釉;周原遗址的原始瓷工艺尚处于制瓷技术初级阶段。     

湖田窑宋代青白瓷的组成及呈色特征

景德镇宋代以生产青白瓷而闻名,其中湖田窑又是景德镇宋代窑址中最典型的一处,其生产的青白瓷精巧细致,有“假玉器”和“饶玉”之称。研究采用能量色散X荧光光谱分析仪和色差计,分析了湖田窑宋代青白瓷的胎、釉化学组成和色度值,初步探讨了不同时期青白瓷的组成、配方和呈色特征。研究表明,湖田窑北宋和南宋青白瓷胎体组成特征基本一致,均与当地瓷石原料较为接近,极有可能采用了附近的三宝瓷石原料制胎。瓷釉组成结果显示釉中含有较高的CaO和一定量的MnO和P₂O₅,表明湖田窑青白瓷釉为“钙釉”,且釉料配方中引入了一定量的草木灰。色度分析结果显示,湖田窑北宋和南宋青白瓷釉主波长分别为500和496 nm左右,均落在可见光波的绿色波段。但对比北宋和南宋瓷釉组成和色度结果发现,北宋青白瓷釉无论是组成还是色度数据结果均较南宋更为分散,且南宋青白瓷釉层呈色相较北宋样品b值更小,釉色更为偏蓝。研究认为,湖田窑青白瓷从北宋至南宋,釉料配方经历了从探索逐渐走向成熟、稳定的过程。研究结果不仅为景德镇湖田窑青白瓷的断源断代提供了数据支撑,也为湖田窑青白瓷制瓷技艺的传承和传播提供了一定的科学素材。     

基于二维光学点阵形变的面形测量

反射镜是光学仪器的核心元件,其面形的精密测量一直是研究领域的重要内容。利用光场调控产生大小灵活可变的空间周期性分布的光学点阵,并提出了一种基于二维光学点阵形变实现面形快速测量的方法。结合几何光学和空间三维变换理论,建立了二维光学点阵几何形变量与反射镜三维面形的数学关联模型,并提出了基于点阵质心的面形重构算法,研究分析了测量方法的测量范围和单像素点分辨率,并对反射镜进行了多倾角的实验测试,实现了对直径为10.5mm的反射镜的亚微米级的测量。通过将测试数据与商用干涉仪的测量数据进行比较,验证了所提方法的可行性。该方法具有测量精度高、速度快和适应强等特点。     

Study on shock wave-induced cavitation bubbles dissolution process

This study investigated dissolution processes of cavitation bubbles generated during in vivo shock wave(SW)-induced treatments. Both active cavitation detection(ACD) and the B-mode imaging technique were applied to measure the dissolution procedure of bi Spheres contrast agent bubbles by in vitro experiments. Besides, the simulation of SW-induced cavitation bubbles dissolution behaviors detected by the B-mode imaging system during in vivo SW treatments, including extracorporeal shock wave lithotripsy(ESWL) and extracorporeal shock wave therapy(ESWT), were carried out based on calculating the integrated scattering cross-section of dissolving gas bubbles with employing gas bubble dissolution equations and Gaussian bubble size distribution. The results showed that(i) B-mode imaging technology is an effective tool to monitor the temporal evolution of cavitation bubbles dissolution procedures after the SW pulses ceased, which is important for evaluation and controlling the cavitation activity generated during subsequent SW treatments within a treatment period;(ii) the characteristics of the bubbles, such as the bubble size distribution and gas diffusion, can be estimated by simulating the experimental data properly.     

Optical coherence tomography

Optical Coherence Tomography (OCT) is a new technology for performing high-resolution cross sectional imaging. OCT is analogous to ultrasound imaging, except that it uses light instead of sound. OCT can provide cross sectional images of tissue structure on the micron scale in situ and in real time. OCT functions as a type of optical biopsy and is a powerful imaging technology for medical diagnostics because unlike conventional histopathology which requires removal of a tissue specimen and processing for microscopic examination, OCT can provide images of tissue in situ and in real time. OCT can be used where standard excisional biopsy is hazardous or impossible, to reduce sampling errors associated with excisional biopsy, and to guide interventional procedures.     

A comparative analysis of reticular crack on ceramic plate driven by thermal shock

Reticular crack is generally found on the surface of ceramic material that has been subjected to a thermal-shock condition. In the present study, a quantitative effect of thermal shock and quench temperature has been studied and investigated. Experimental tests were carried out to characterize the reticular crack that has been found in the Ge Kiln, which is a famous art of the ancient Chinese culture. After comparative analysis between thermal-shock cracks and the glaze crack patterns of the Ge Kiln porcelain, it is found that this study is expected to provide a powerful tool for recurrence of the long-lost firing and cooling process of the Ge Kiln porcelain.     

景德镇五代瓷器组成配方的EDXRF分析

景德镇早期制瓷工艺一直是学术界所关注的焦点问题之一。采用能量色散X射线荧光法分析了景德镇五代时期湘湖窑出土白瓷和青瓷样品的胎釉元素组成,并据此探讨其原料和配方。研究表明,五代时期景德镇湘湖窑白瓷胎体所用原料为瓷石,而青瓷瓷胎应是采用瓷石配以紫金土的二元配方;白瓷和青瓷瓷釉皆使用釉果加釉灰的配方,且青瓷瓷釉配方中釉灰的用量高于白瓷瓷釉。     

In-situ synchrotron X-ray imaging of ultrasound (US)-generated bubbles: Influence of US frequency on microbubble cavitation for membrane fouling remediation

Gaining an in-depth understanding of the characteristics and dynamics of ultrasound (US)--generated bubbles is crucial to effectively remediate membrane fouling. The goal of present study is to conduct in-situ visualization of US-generated microbubbles in water to examine the influence of US frequency on the dynamics of microbubbles. This study utilized synchrotron in-line phase contrast imaging (In-line PCI) available at the biomedical imaging and therapy (BMIT) beamlines at the Canadian Light Source (CLS) to enhance the contrast of liquid/air interfaces at different US frequencies of 20, 28 and 40 KHz at 60 Watts. A high-speed camera was used to capture 2,000 frames per second of the bubble cavitation generated in water under the ultrasound influence. Key parameters at the polychromatic beamlines were optimized to maximize the phase contrast of gas/liquid of the microbubbles with a minimum size of 5.5 µm. ImageJ software was used to analyze the bubble characteristics and their behavior under the US exposure including the microbubble number, size, and fraction of the total area occupied by the bubbles at each US frequency. Furthermore, the bubble characteristics over the US exposure time and at different distances from the transducer were studied. The qualitative and quantitative data analyses showed that the microbubble number or size did not change over time; however, it was observed that most bubbles were created at the middle of the frames and close to the US field. The number of bubbles created under the US exposure increased with the frequency from 20 kHz to 40 kHz (about 4.6 times). However, larger bubbles were generated at 20 kHz such that the average bubble radius at 20 kHz was about 6.8 times of that at 40 kHz. Microbubble movement/traveling through water was monitored, and it was observed that the bubble velocity increased as the frequency was increased from 20 kHz to 40 kHz. The small bubbles moved faster, and the majority of them traveled upward towards the US transducer location. The growth pattern (a correlation between the mean growth ratio and the exposure time) of bubbles at 20 kHz and 60 W was obtained by tracking the oscillation of 22 representative microbubbles over the 700 ms of imaging. The mean growth ratio model was also obtained.     

Laser computed tomography of opaque industrial products measured by coherent detection imaging method

The coherent detection imaging method with a low-power He–Ne laser as the source is used to obtain transillumination laser computed tomographic and two-dimensional (2D) images of opaque industrial products such as fluorescent lamps and electric light bulbs. This method is principally based on the optical heterodyne detection technique that has the highest sensitivity along with excellent selectivity in terms of coherence, polarization and high directionality. Structures of the filament and electrode enclosed in the opaque glass were clearly identified with submillimeter resolution.     

Quantitative 'real-time' imaging of multi-phase flow in ceramic monoliths

An extension of the RARE technique has been developed which acquires multiple images from a single radio-frequency excitation. This pulse sequence has been used to image, in real-time, gas flow through stagnant liquid within parallel-channel ceramic monoliths. From these images, gas-phase volume fractions, and distributions of gas bubble length and velocity as a function of gas flow rate (50-300 cm3 min(-1)) and channel size (300 and 400 channels per square inch, cpsi) are obtained directly. Increasing the gas flow rate increased the number of large bubbles and the average bubble velocity. A bimodal distribution in the bubble velocities was observed for flow within the larger channel size (300 cpsi) in contrast to a broad unimodal distribution characterizing two-phase flow within the smaller channel size (400 cpsi).