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2. An insight into the origin of elemental chromium in the lacquer of Qin terracotta warriors

Author

Yang Chenchen, Rong Bo, Huang Jing, Chen Xutong, Lan Desheng, He Fengyi, Yan Shaojun, He Ling, Meng Lingjie, Liang Junyan, and Lu Wenxian

Subjects
Qin terracotta warriors, Lacquer, Elemental chromium, Migration, Mechanism, Fine Arts, Analytical chemistry, QD71-142
Abstract

Abstract The origin of elemental chromium for the archaeological weapons from the pits of Qin terracotta warriors in China has been highly controversial. Although previous studies have highlighted that the chromium on the surface of weapon originated from the contamination of surrounding lacquer, the exact origin of chromium in the lacquer remains unclear. In this work, the measurement by inductively coupled plasma-mass spectrometer (ICP-MS) firstly confirmed that the elemental chromium was indeed contained in the archaeological Qin original lacquer. Nevertheless, the amount of elemental chromium in the Qin lacquer was as low as 0.0759 μg/mg, disclosing that it was impossible to artificially add extra refined chromium-containing substance to the lacquer in the preparation of the terracotta warriors. The soil from the archaeological site of Qin lacquer was found to have a chromium amount of 0.0660 μg/mg by ICP-MS. After the hygrothermal and soil-buried aging cycles for the lab-prepared lacquer, the surface and depth elemental analyses by time of flight-secondary ion mass spectrometer (TOF–SIMS) showed a gradient distribution of elemental chromium from the surface to interior of aged lacquer, indicating the migration and enrichment behavior of elemental chromium from the burial soil towards the lacquer. To explore the migration mechanism of elemental chromium, fluorescence imaging technique was employed in combination with Fourier transform infrared spectrometry (FT-IR) and X-ray photoelectron spectroscopy (XPS) characterizations. The results revealed that catechol-containing fragments were formed during hygrothermal and soil-buried aging of lacquer and consequently coordinated with chromium ions, inducing the migration of elemental chromium towards the lacquer.

Published
2024
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3. The Chinese H{\alpha} Solar Explorer (CHASE) mission: An overview

Author

Li, Chuan, Fang, Cheng, Li, Zhen, Ding, MingDe, Chen, PengFei, Qiu, Ye, You, Wei, Yuan, Yuan, An, MinJie, Tao, HongJiang, Li, XianSheng, Chen, Zhe, Liu, Qiang, Mei, Gui, Yang, Liang, Zhang, Wei, Cheng, WeiQiang, Chen, JianXin, Chen, ChangYa, Gu, Qiang, Huang, QingLong, Liu, MingXing, Han, ChengShan, Xin, HongWei, Chen, ChangZheng, Ni, YiWei, Wang, WenBo, Rao, ShiHao, Li, HaiTang, Lu, Xi, Wang, Wei, Lin, Jun, Jiang, YiXian, Meng, LingJie, and Zhao, Jian

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The Chinese H{\alpha} Solar Explorer (CHASE), dubbed "Xihe" - Goddess of the Sun, was launched on October 14, 2021 as the first solar space mission of China National Space Administration (CNSA). The CHASE mission is designed to test a newly developed satellite platform and to acquire the spectroscopic observations in the H{\alpha} waveband. The H{\alpha} Imaging Spectrograph (HIS) is the scientific payload of the CHASE satellite. It consists of two observational modes: raster scanning mode and continuum imaging mode. The raster scanning mode obtains full-Sun or region-of-interest spectral images from 6559.7 to 6565.9 {\AA} and from 6567.8 to 6570.6 {\AA} with 0.024 {\AA} pixel spectral resolution and 1 minute temporal resolution. The continuum imaging mode obtains photospheric images in continuum around 6689 {\AA} with the full width at half maximum of 13.4 {\AA}. The CHASE mission will advance our understanding of the dynamics of solar activity in the photosphere and chromosphere. In this paper, we present an overview of the CHASE mission including the scientific objectives, HIS instrument overview, data calibration flow, and first results of on-orbit observations., Comment: 9 pages, 6 figures

Published
2022
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15. Unveiling the secrets of the mid-infrared Moon

Author

Wu, Yunzhao, Jin, Qi, Li, Cui, Xu, Tianyi, Qi, Wenwen, Tan, Wei, Li, Xiaoman, Shi, Zhicheng, He, Hongyan, Dai, Shuwu, Li, Guo, Liu, Fengjing, Wang, Jingqiao, Wang, Xiaoyan, Lu, Yu, Cai, Wei, Wang, Qi, and Meng, Lingjie

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The Moon's optical characteristics in visible and long-wavelength infrared (LWIR) have long been observed with our eyes or with instruments. What the mid-infrared (MIR) Moon looks like is still a mystery. For the first time we present detailed appearance of the MIR Moon observed by a high-resolution geostationary satellite and reveal the essence behind its appearance. The appearance of the MIR Moon is opposite to its normal visible appearance. In addition the MIR Moon shows limb darkening. Both the absolute and the relative brightness distribution of the MIR lunar disk changes with the solar incidence angle. The signatures of the MIR Moon are controlled by both the reflection and emission of the lunar surface. We also show first-ever brightness temperature maps of the lunar disk without needing a mosaic, which better show the temperature variation across the lunar disk. They reveal that the relationship between brightness temperature and solar incidence angle i is cos1/bi, and the power parameter is smaller than the Lambertian temperature model of cos1/4i observed for lunar orbit-based measurements. The slower decrease of the brightness temperature when moving away from the sub-solar point than the Lambertian model is due to topographic effects. The brightness temperature is dominated by albedo and the solar incidence angle and influenced by the topography. Our results indicate that the Moon in the MIR exhibits many interesting phenomena which were previously unknown, and contains abundant information about lunar reflection and thermal emission for future study.

Published
2020
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37. Maytenhoiridosides A and B, two new iridoid glycosides from the branches of Maytenus hookeri.

Author

Lv, Huijing, Kong, Qinghong, Song, Changwei, Yang, Jiawei, and Meng, Lingjie

Abstract

Two new iridoid glycosides, maytenhoiridosides A (1) and maytenhoiridosides B (2), along with three known compounds (3 – 5), were isolated from the branches of Maytenus hookeri. Their chemical structures were elucidated by HR-ESI-MS, 1D and 2D-NMR spectra, acid hydrolysis analysis, and comparison with literature data. Among the isolated compounds, compound 5 exhibited significant cytotoxic activity against the HCT-116, SKOV3 and SK-Hep-1 cells, with IC 50 values of 9.49±1.40, 34.66±1.48 and 12.66±3.32 µM, respectively, while the others showed weak or no activity at 50 μM. [Display omitted] • Two new iridoid glycosides were isolated from Maytenus hookeri. • The structures were confirmed by extensive spectroscopic analyses. • Compound 5 exhibited significant cytotoxic activities. [ABSTRACT FROM AUTHOR]

Published
2024
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38. Undetected Association Between Fatty Acids and Dementia with Lewy Bodies: A Bidirectional Two-Sample Mendelian Randomization Study.

Author

Zhai, Weijie, Zhao, Anguo, Wei, Chunxiao, Xu, Yanjiao, Cui, Xinran, Zhang, Yan, Meng, Lingjie, and Sun, Li

Subjects
OMEGA-6 fatty acids, MONOUNSATURATED fatty acids, UNSATURATED fatty acids, LEWY body dementia, OMEGA-3 fatty acids
Abstract

Background: Although observational studies indicated connections between fatty acids (FAs) and Alzheimer's disease and dementia, uncertainty persists regarding how these relationships extend to dementia with Lewy bodies (DLB). Objective: To explore the potential causal relationships between FAs and the development of DLB, thus clarifying these associations using genetic instruments to infer causality. Methods: We applied a two-sample Mendelian randomization (MR) and multivariable Mendelian randomization (MVMR) approach. Genetic data were obtained from a DLB cohort, comprising 2,591 cases and 4,027 controls of European descent. Eight FAs, including linoleic acid, docosahexaenoic acid, monounsaturated fatty acid, omega-3 fatty acid, omega-6 fatty acid, polyunsaturated fatty acid, saturated fatty acid, and total fatty acid, were procured from a comprehensive GWAS of metabolic biomarkers of UK Biobank, conducted by Nightingale Health in 2020 (met-d), involving 114,999 individuals. Our analysis included inverse-variance weighted, MR-Egger, weighted-median, simple mode, and weighted-mode MR estimates. Cochran's Q-statistics, MR-PRESSO, and MR-Egger intercept test were used to quantify the heterogeneity and horizontal pleiotropy of instrumental variables. Results: Only linoleic acid showed a significant genetic association with the risk of developing DLB in the univariate MR. The odds ratio for linoleic acid was 1.337 with a 95% confidence interval of 1.019–1.756 (pIVW = 0.036). Results from the MVMR showed that no FAs were associated with the incidence of DLB. Conclusions: The results did not support the hypothesis that FAs could reduce the risk of developing DLB. However, elucidating the relationship between FAs and DLB risk holds potential implications for informing dietary recommendations and therapeutic approaches in DLB. [ABSTRACT FROM AUTHOR]

Published
2024
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