Entity

Time filter

Source Type

Taipei, Taiwan

Yu B.-S.,National Taipei University of Technology | Fang J.-N.,National Taiwan Museum | Huang E.-P.,Meiho University
Journal of Raman Spectroscopy | Year: 2013

Archaeological malachites, represented by the malachites found on the ancient Chinese and Vietnamese copper/bronze coins, may also incorporate those on other archaeological objects. The Raman spectra with Ar laser of these malachites differ slightly from those of the natural malachites found in mines. In this study, 120 measurements of the malachites on 40 coins identified 26 bands, while only around 18 of them are frequently observed. The wavenumbers (cm-1), shifts (±)and relative intensities (in parentheses) of the 18 common bands read, respectively: 153±4 (0-vs), 179±7 (m-vs), 217±8 (m-vs), 274±7 (0-vs), 355±5 (0-m), 431±4 (0-vs), 514±3 (0-m), 533±5 (0-s), 566±3 (0-m), 599±2 (0-m), 718±6 (0-m), 754±2 (0-m), 1061±7 (0-m), 1093±10 (0-m), 1365±9 (0-m), 1491±7 (0-vs), 3321±11 (0-vs) and 3380±7 (0-vs). In comparison with those of the 105 measurements on the natural malachites in five mines, the Raman spectra of the archaeological malachites tend to show less bands, higher backgrounds and greater shifts in the wavenumber position. The weakening or loss of bands is in the order of the OH stretch (3300 cm-1) (most severe), CO3 (600-1500 cm-1) and CuO (<600 cm-1) (less severe) groups, indicating successive stages of corrosion. The malachites on the coins from three climate zones show their own characteristics. Several coins may have experienced two or more climatic or geologic episodes and show complex Raman spectra different from those of the natural malachites. Copyright © 2012 John Wiley & Sons, Ltd. Source


Huang E.-P.,National Cheng Kung University | Huang E.,Chung Chou University of Science and Technology | Yu S.-C.,National Cheng Kung University | Chen Y.-H.,National Cheng Kung University | And 2 more authors.
Materials Letters | Year: 2010

This study presents the results of the first use of the moissanite anvil cell (MAC) for the in-situ high-temperature and pressure Raman spectroscopy measurement of diamond. It is observed that the T2g vibrational mode of diamond shifts toward low frequency with increasing temperature; on the other hand, the vibration band shifts toward high frequency with increasing pressure. In the high-temperature and pressure process, the slope (∂υ/∂T) becomes zero which indicates the thermal expansion. It resulted from the temperature effect, and the pressure caused by MAC will reach a balanced state about 1.6 GPa and 175 °C. The behavior of diamonds at high temperature and high pressure is mainly dominated by temperature effects for the temperature below 320 °C and the pressure less than 5 GPa. Crown Copyright © 2009. Source


Huang E.-P.,National Cheng Kung University | Huang E.,Chung Chou University of Science and Technology | Yu S.-C.,National Cheng Kung University | Chen Y.-H.,National Cheng Kung University | And 2 more authors.
Physics and Chemistry of Minerals | Year: 2010

Kerogen samples were treated at temperatures and pressures up to 25-600°C and ~9 GPa, respectively. In situ micro-Raman spectroscopy was used to measure the systematic changes in the first-order Raman spectral features during the process of temperature or pressure increment. Three Raman bands, D1, D2, and G bands, were examined to characterize the structural and chemical changes of kerogen at high temperatures and pressures. We found that the wavenumbers of D1, D2 and G bands showed a linear variation with both temperature and pressure. Therefore, a correlation between R1 and R2 and the peak temperature in regionally metamorphosed rocks cannot be applied to this work. This result implies that the G band may serve as a temperature or pressure indicator during the promotion of maturation of kerogen. Kerogen possesses reversible properties in contrast with the natural samples recovered from the field suffered from prolonged thermal history during regional metamorphism. © 2010 Springer-Verlag. Source


Wang L.-C.,National Taiwan Museum | Wang L.-C.,University of Gottingen | Behling H.,University of Gottingen | Kao S.-J.,Xiamen University | And 4 more authors.
Journal of Asian Earth Sciences | Year: 2015

We used multi-decadal pollen and diatom records from sediment core TFL-1 from Tsuifong Lake to reconstruct the vegetation dynamics and hydroclimate in northeastern Taiwan during the past 3500. cal BP. Coarse grained sediments in association with higher percentages of wetland pollen (Cyperaceae) and upper conifer pollen (. Tsuga and Pinus) in the lower part of the core indicate low lake levels and a relatively cold/dry climate between 3500 and 2030. cal BP, reflecting a decline of the East Asian summer monsoon (EASM). Muddy sediments coupled with reduction of wetland pollen represent the rise of lake levels, implying the re-strengthening of the EASM during the past 2000. years. Paleotemperature was inferred from the variation of pollen origin from the upper and lower mountain forest, indicating the global temperature anomalies of the Medieval Warm Period (MWP) and the Little Ice Age (LIA). In comparison to the main climate forces in the North Pacific, we suggest that the long-term climatic trend in Taiwan was controlled by variations in EASM intensity, while increased precipitation over the past 2000. years may also be linked to warmer sea surface temperature (SST) of the western Pacific Warm Pool (WPWP) and increased El Niño-Southern Oscillation (ENSO) events, which increased typhoon intensity. Higher diatom-inferred pH during 2930-2030. cal BP and the LIA suggest strong hydrological disturbances, reflecting more typhoons passing over Taiwan. The frequent typhoon events could be linked by an abrupt shift of typhoon track, due to the reduction of the WPWP and expansion of the Northwestern Pacific High, which move typhoons in a more westerly direction. © 2015 Elsevier Ltd. Source


Lee J.C.-I.,National Taiwan University | Lee J.C.-I.,Institute of Forensic Medicine | Tsai L.-C.,Central University of Costa Rica | Hwa P.-Y.,Central University of Costa Rica | And 7 more authors.
Molecular and Cellular Probes | Year: 2010

We report on a novel and rapid strategy for the simultaneous identification of both avian species and gender by analyzing a section of the CHD gene. The CHD gene is carried by the avian sex determining chromosomes where a female bird carries both a W and Z chromosome but a cock bird carries two copies of the Z chromosome. Two primer pairs, CHD1F/CHD1R and P2/P8, were used to amplify a part of the CHD gene from 144 samples corresponding to 58 avian species. For all species tested, two fragments were observed at least in one amplification for female samples. All tested species produced species specific size fragments allowing both sex determination and species identification using these primer pairs. However, special care is still warranted as so few samples have been characterised. This novel strategy for avian species and gender identification using the CHD gene was developed for a number of applications from ecology to forensic science. © 2009 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations