[Preliminary Research on Bubble Characteristics of Ancient Glaze Using OCT Technology].

The bubble is one of the most common feature in ancient glaze. The size and distribution of bubbles are closely associated with recipes of the raw materials for the body and glaze and the making process. To characterize the bubbles is essential for the study of ceramic production process, production places, times characteristics and so on. In order to explore the possibility of using the optical coherence tomography (OCT) imaging technology to characterize the bubbles and the bubble distribution characteristic in glaze of ancient porcelain, sweep frequency OCT imaging system is used to detect five different types ancient porcelain chips. According to the two dimensional sectional images and three dimensional tomographic images of the transparent layer of glaze obtained by the OCT imaging system, the two dimensional sectional images characteristics and three dimensional slices characteristics of the bubbles in glaze are studied. The bubble characteristics in the glaze and its possible causes that gases in the body of the ceramic overflow to the glaze layer in the firing process are comprehensively analyzed. Meantime, the size of bubble is calculated according to the two dimensional sectional images based on pixel, and the result is compared with the traditional microscopic test result. The bubble size, two dimensional sectional characteristics and three dimensional tomographic image characteristics of opaque glaze are also studied. Experimental results show that the bubble characteristics in glaze of different ancient porcelain chips are obvious difference, the result of the bubble size calculated based on pixel coincides with the result of the bubble size observed by traditional microscope with ten times magnification, slices of the body near the body-glaze binding region based on OCT imaging technology three dimensional tomography can effectively reflect the bubble characteristics in glaze. The measurement of using OCT imaging technology to characterize bubble characteristics of the glaze is proposed, and the feasibility and the validity of the measurement are certified, and the nondestructive detection of bubble characteristics in ancient porcelain glaze is realized. Especially for the analysis of bubble characteristics of opaque glaze, the OCT imaging technology overcomes the limitations of using the traditional microscope technology to study the distribution of bubble in glaze in the past, and provides a novel, reliable analysis method for the analysis of ceramic glaze bubble characteristics.

[The Non-Destructive Analysis of Some Ancient Jade Artifacts Unearthed from Henan Province by a Variety of Optical Techniques].

A total of 14 pieces of ancient jade artifact unearthed from Henan Province were non-destructively analyzed by means of a portable X-ray fluorescence spectrometer (pXRF), laser Raman spectroscopy (portable and mobile) and optical coherence tomography (OCT) technology, comprehensively. The raw materials of ancient jade artifacts could be determined accurately through the combination of pXRF and portable Raman spectrometer in a short time. With the advantages of small size and easy-operation, these two instruments are suitable to in situ non-destructive analysis of ancient jade artifacts. The results of the pXRF shows that these ancient jade artifacts can be divided into 6 categories such as rich in Si Al K, rich in Ca, rich in Si Ca, rich in Si Mg, rich in Si, rich in Ca P. Their main phases have been successfully identified by the portable Raman spectrometer. In the lab, the mobile confocal laser Raman spectrometer, which help us find the Raman vibration peak of [OH] in the tremolite jade, is used to make up the disadvantages of the portable Raman spectrometer such as lower spectral resolution, lower accuracy and narrower measuring range. We can use the OCT to analyze the transparency, fiber fineness and inclusion etc. of the jade artifacts. The confocal laser Raman spectroscopy combined with OCT is used to analyze 2 containing inclusion of tremolite jade samples. OCT image can visually display the distribution characteristics of the inclusion in these 2 samples. Confocal laser Raman spectroscopy can accurately locate the sample surface of inclusion, then we can observe the micro morphology and analyze its phase. The results show that the black inclusion is graphite. This work is very significant to study the geographical origin of jade. Through the study we find, the use of pXRF, laser Raman spectroscopy (portable and mobile) and OCT can be achieved on the identification and analysis of cultural relic's phase composition and texture feature and meet the basic requirements of field archaeological work analysis.

[Nondestructive analysis of the silicate artifacts excavated from Baofeng and Xinzheng, Henan Province].

Nondestructive analysis plays an important role in the studies of ancient artifacts. The present paper reports the chemical compositions and micro-area phases of 21 silicate artifacts samples analyzed by portable X-ray fluorescence spectrometer and laser Raman spectrometer. Based on the chemical compositions, these samples can be divided into PbO-BaO-SiO2, K2O-SiO2 glass systems, faience and PbO-BaO glassy faience which were discussed respectively, and preliminary investigation of colorants in different parts of some samples was also involved. By laser Raman spectroscopy, Chinese blue (BaCuSi4O10), Chinese purple (BaCuSi2O6) and Chinese dark blue (BaCu2Si2O7) were identified invasively in the blue pigment of some eye beads and circle beads, and then a variety of mineral phase including quartz, calcite, lead carbonate, burnt umber and terre verte were also analyzed successfully in the same way. According to the archaeological research results, the provenances of these samples were discussed briefly. PbO-BaO-SiO2 glass, K2O-SiO2 ear pendant and PbO-BaO glassy faience were made in China while the faience was suspected to be from the west. Those results illustrated the communications of culture and technologies among different regions of ancient China, and between ancient China and the western regions. The combination of portable X-ray fluorescence spectrometer and laser Raman spectrometer can provide chemical and phase information of relics, and has great advantages in scientific analysis of ancient artifacts, which supports future studies of archaeology.