Trace Element Analysis by PIYE and ICP-AES of Raw Material and Ancient Serpentine Artifacts from China.

This work mainly talks about serpentine mineral with the aim to explore the possible raw materials sources of ancient serpentine artifacts by trace element content analysis. The major and trace elements of serpentine samples from several typical deposits in China were nondestructively determined by external-beam proton-induced X-ray emission (PIXE). For comparison, trace element concentrations were destructively measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The results showed the trend of the trace element contents of serpentine jade obtained by the two methods have preferably coherence, which indicate that the nondestructive technique of PIXE can be applied to trace element analysis of serpentine. The relationship between trace element contents and serpentine formation mechanism was discussed. The difference of the trace elements contents in these serpentine minerals is obvious. It can be used to distinguish the different kinds of serpentine formed by different mechanisms. A low amount of Ni and almost no Cr and Co were found in type I serpentine group mineral, whereas significant amounts of Cr, Co and Ni were found in Type II serpentine group mineral. The chemical composition of 18 ancient serpentine artifacts were analyzed by PIXE, they were unearthed from 14 sites and tombs in provinces of Zhejing, Jiangsu, Henan, Anhui and Hubei and dated from Neolithic Age to the Warring States Period (4585 BC­231 BC). By comparing the trace element contents between ancient serpentine artifacts and two kinds of serpentine samples, the provenance of ancient serpentine artifacts were preliminarily inferred. It is beneficial to try to explore the possible raw material of ancient serpentine artifacts based on the relationship between the trace element contents and serpentine formation mechanism in this article.

[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.

[Application of calibration curve method and partial least squares regression analysis to quantitative analysis of nephrite samples using XRF].

The authors tried to find a method for quantitative analysis using pXRF without solid bulk stone/jade reference samples. 24 nephrite samples were selected, 17 samples were calibration samples and the other 7 are test samples. All the nephrite samples were analyzed by Proton induced X-ray emission spectroscopy (PIXE) quantitatively. Based on the PIXE results of calibration samples, calibration curves were created for the interested components/elements and used to analyze the test samples quantitatively; then, the qualitative spectrum of all nephrite samples were obtained by pXRF. According to the PIXE results and qualitative spectrum of calibration samples, partial least square method (PLS) was used for quantitative analysis of test samples. Finally, the results of test samples obtained by calibration method, PLS method and PIXE were compared to each other. The accuracy of calibration curve method and PLS method was estimated. The result indicates that the PLS method is the alternate method for quantitative analysis of stone/jade samples.

[Coloration mechanism and chromaticity of Xiuyan Jade of China].

The coloration mechanism of Xiuyan Jade was studied with the chemical composition, valance and coordination states of transition metal ions. The result of inductively-coupled plasma atom emission spectrometer (ICP-AES) indicated that there are little other transition metal elements except for iron and manganese. Electron paramagnetic resonance (EPR) revealed that Fe3+ ions locate at both octahedral sites and tetrahedral sites. Optical absorption spectrum (OAS) showed the presence of Fe2+ and Fe3+ ions. Moreover, depending on the results of OAS, Fe2+ ions determine the green color of Xiuyan Jade, while the coexistence of Fe3+ and Fe2+ ions introduces the yellow color of Xiuyan Jade. The chromaticity coordinate was calculated according to diffuse reflectance spectrum. The result demonstrated that chromaticity coordinates can be used to quantitatively distinguish Xiuyan Jade with similar color, which can provide a scientific reference for the evaluation of the value of Xiuyan Jade.

[Influence of cations on the laser Raman spectra of silicate glasses].

Na2O(K2O)-CaO(MgO)-SiO2, Na2O(K2O)-Al2O3-SiO2, Na2O(K2O)-B2O3-SiO2, Na2O(K2O)-PbO-SiO2 and PbO-BaO-SiO2 glass systems were investigated using laser Raman spectroscopic technique. The modification of short-range structure of glass caused by network modifier cations will influence Raman signature. Alkali and alkali-earth ions can weaken the bridging oxygen bond, thus lower the frequency of Si-O(b)-Si anti-symmetric stretching vibration. When coordina ted by oxygen ions, B3+ can form [BO4] tetrahedron and enter the silicon-oxygen network, but this effect had little impact on the frequency of Raman peaks located in the high-frequency region. Al3+ can also be coordinated by oxygen ions to form [AlO4] tetrahedron. [AlO4] will increase the disorder degree of network while entering network. Ba2+ can increase the density of electron cloud along the Si-O(nb) bond when it bonds with non-bridging oxygen, which will lead to a higher peak intensity of O-Si-O stretching vibration. The Raman peaks of alkli- and alkali-earth silicate glasses are mainly distributed in the region of 400 - 1 200 cm(-1), while in the spectrum of Na2O(K2O)-PbO-SiO2 glass system a 131 cm(-1) peak existed. The authors assigned it to the Pb-O symmetric stretching vibration. Some of the samples were produced in the laboratory according to the average compositions of ancient glasses, so this research is very significant to discriminating ancient silicate glasses of different systems by Laser Raman spectroscopic technique.

[Influence of ancient glass samples surface conditions on chemical composition analysis using portable XRF].

Portable X-ray fluorescence analysis (PXRF) is one kind of surface analysis techniques, and the sample surface condition is an important factor that influences the quantitative analysis results. The ancient glass samples studied in the present paper were excavated from Xinjiang, Guangxi, Jiangsu provinces, and they belong to Na2O-CaO-SiO2, K2O-SiO2, and PbO-BaO-SiO2 system, respectively. Quantitative analysis results of weathered surface and inside of the ancient glass samples were compared. The concentration change of main fluxes in different parts of the samples was pointed out. Meanwhile, the authors studied the effect of distance between the sample and the reference plane, and curve shape of the sample on the quantitative results. The results obtained were calibrated by three methods, and the validity of these three methods was proved. Finally, the normalizing method was proved to be a better method for quantitative analysis of antiques. This paper also has guiding significance for chemical composition analysis of ancient jade samples using PXRF.

[Nondestructive analysis of chemical composition, structure and mineral constitution of jadeite jade].

The techniques of portable energy-dispersive X-ray fluorescence analysis (PXRF), proton induced X-ray emission spectroscopy (LRS) were employed to analyze the chemical composition, structure and mineral constitution of 12 samples. The results indicated that the chemical compositions determined by PXRF and PIXE are well comparable and most samples are constituted by almost pure jadeite with low concentration of secondary elements. One sample contains a little omphacite and one sample is composed only by omphacite. Raman characteristic peaks of jadeite occurred at 201, 372, 698, 985 and 1 037 cm(-1), while those of omphacite located at 680 and 1 017 cm(-1). By using laser Raman spectroscopy for testing the fissures of the samples, wax in 3 samples and epoxy resin in one sample were found. Raman characteristic peaks of wax located at 2 846 and 2 880 cm(-1) and those of epoxy resin occurred at 2 924 and 3 065 c(-1). The application of nondestructive techniques in jadeite jade broadens the range of samples for future study and provides technical support for jadeite jade's further study, identification and classification.

[Applacation of portable energy-dispersive X-ray fluorescence spectrometer in chemical composition analysis of Chinese ancient glass].

Chemical composition is one of the most important aspects in the study of Chinese ancient glasses, as it could provide scientific proofs for the technical origin and development of Chinese ancient glasses. It is very necessary to find out some new an alyzing techniques. One of the most remarkable advantages for portable X-ray fluorescence technique is its portability, which allows antiques that can't be allowed to move out of museum to be analyzed. The basic principles, performances and analysis process of the equipment that was improved by OURSTEX company and Center of Sci-tech Archaeology of Shanghai Institute of Optics and Fine Mechanics are presented in detail. Some examples for the application of portable X-ray fluorescence spectrometer in chemical composition analysis of Chinese ancient glass samples excavated from Xinjiang province are also given. The results are compared with that determined by the proton induced X-ray fluorescence technique. There is a potential application for portable X-ray fluorescence technique in on site analysis.

[Application of Raman spectroscopic technique to the identification and investigation of Chinese ancient jades and jade artifacts].

Laser Raman spectroscopic technique is one of the essential methods in scientific archaeological research, which belongs to the nondestructive analysis. As a very good nondestructive analysis approach, it has not been widely applied in the research of the Chinese ancient jade artifacts. First of all in the present paper the fundamentals of laser Raman spectroscopic technique and the new research progress in this field were reviewed. Secondly, the Raman spectra of five familiar jades including nephrite (mainly composed of tremolite), Xiuyan Jade (mainly composed of serpentine), Dushan Jade (mainly composed of anorthite and Zoisite), turquoise and lapis lazuli were summarized respectively. As for an example, the Raman spectra of the four Chinese ancient jade artifacts excavated from Liangzhu Site of Zhejiang Province and Yinxu Site of Anyang in Henan Province were compared with that of the nephrite sample in Hetian of Xinjiang Province. It was shown that the Raman spectroscopic technique is a good nondestructive approach to the identification and investigation of the structures and mineral composition of Chinese ancient jade artifacts. Finally, the limitations and the foreground of this technique were discussed.

[Cooperative luminescence in Yb:YAG crystals].

Cooperative luminescence phenomenon of Yb:YAG crystals was studied. Up-converted blue luminescence was obviously observed in Yb:YAG under excitation in the near-infrared region with a wavelength 940 nm. Experimental evidence was provided by the fact that the intensity of 498 nm luminescence shows a quadratic dependence on excitation power, and the intensity of blue luminescence increased with the increase in Yb ion concentration. It is concluded that this luminescence is due to a cooperative process resulting from a strong interaction of Yb ions. The cooperative luminescence is possiblely assigned to the strong interaction of 4f(13) electrons and neighboring Yb3+ ions in a covalent host lattice such as YAG. Theoretical cooperative luminescence spectrum was calculated.

[Study on the spectral properties of a new fluorene derivative].

A new big pi-conjugated, symmetrical fluorene derivative, 9, 9-bis(2-ethylhexyl)-2,7-bis(2-(4-methoxy) benzene-2, 1-ethenyl) fluorene (abbreviated as MO-Flu-MO) was synthesized and characterized by elemental analysis, mass spectral, UV-Vis and IR spectral. Spectral characteristics of this compound, including linear absorption spectral and one-photon fluorescence spectral, were measured in acetonitrile, methylene chloride, tetrahydrofuran and hexane at room temperature. It was found that solvent effects have different influence on absorption spectral and fluorescence spectral, major reasons of such spectral behavior are discussed.

[Spectroscopy of alpha-isoxazoleazoxyl-beta-diketone derivatives and their tautomers].

In this paper, the IR and UV-Vis spectroscopy of five novel alpha-isoxazoleazoxyl-beta-diketone derivatives with different structures have been studied, and their keto-enol and azo-hydrazone tautomeric phenomena have been discussed. It was found that all compounds, which are in the solid or in the solution, exist in the form of hydrazodiketo and azoenol isomers. The authors can also see that there are two absorption bands which are in the range 246-262 nm and 326-339 nm, respectively, for all compounds in the UV spectra, and the intensities of long wavelength absorption bands which are attributed to azoenol forms are stronger than short wavelength absorption bands which are attributed to hydrazodiketo forms. This shows that the quantities of azoenol forms in the compounds are more than hydrazodiketo forms, and it may be due to that the varieties of the azoenol isomers can easily form six-membered rings structure in the form of intramolecular hydrogen bonding, and make chemical structures more stable.

[Ester derivatives of tetracyanoquinodimethane and their CT complexes: synthesis and studies by infrared spectroscopy].

Three ester derivatives of tetracyanoquinodimethane and their CT complexes were synthesized and characterized by elementary analysis and infrared spectra. The principal infrared absorption peaks were assigned and discussed for the region of 4000-400 cm(-1). Principal factors affecting principal infrared absorption were analyzed.