IMPROVED FORMULA FOR FATIGUE CRACK GROWTH RATEUNDER DIFFERENT STRESS RATIO

An improved formula for fatigue crack growth rate in mode I,mode III and mixed mode I-III under different stress ratio R was proposed,which was based on J-integral range ΔJ. In the formula,the test data under different R could be normalized by correction factor M,which changed the test ΔJ under different R to ΔJeq0under R = 0,and the relationship of M and R was obtained empirically. The proposed formula was validated with available experimental fatigue crack growth data in mode I,mode III and mixed mode I-III under different stress ratio from literatures. It transpires that these test data can be well described with the present formula

A metabolomic investigation of the effects of metal pollution in oysters Crassostrea hongkongensis

Metal pollution has been of great concern in the estuaries in Southern China. In this study, metabolic differences between oysters Crassostrea hongkongensis from clean and metal-polluted sites were characterized using NMR-based metabolomics. We collected oyster samples from one clean (Jiuzhen) and two metal polluted sites (Baijiao and Fugong). The metal concentrations in oyster gills indicated that both the Baijiao and Fugong sites were severely polluted by several metals, including Cr, Ni, Cu, Zn, Ag, Cd and Pb. In particular, Cu and Zn were the major contaminants from the Baijiao and Fugong sites. Compared with those oysters from the clean site (JZ), metal pollution in BJ and FG induced disturbances in osmotic regulation and energy metabolism via different metabolic pathways, as indicated by different metabolic biomarkers. This study demonstrates that NMR-based metabolomics is a useful tool for characterizing metabolic responses induced by metal pollution. (C) 2014 Elsevier Ltd. All rights reserved

A metabolomic investigation of the effects of metal pollution in oysters Crassostrea hongkongensis

Metal pollution has been of great concern in the estuaries in Southern China. In this study, metabolic differences between oysters Crassostrea hongkongensis from clean and metal-polluted sites were characterized using NMR-based metabolomics. We collected oyster samples from one clean (Jiuzhen) and two metal polluted sites (Baijiao and Fugong). The metal concentrations in oyster gills indicated that both the Baijiao and Fugong sites were severely polluted by several metals, including Cr, Ni, Cu, Zn, Ag, Cd and Pb. In particular, Cu and Zn were the major contaminants from the Baijiao and Fugong sites. Compared with those oysters from the clean site (JZ), metal pollution in BJ and FG induced disturbances in osmotic regulation and energy metabolism via different metabolic pathways, as indicated by different metabolic biomarkers. This study demonstrates that NMR-based metabolomics is a useful tool for characterizing metabolic responses induced by metal pollution

Investigating the late neolithic millet agriculture in Southeast China: New multidisciplinary evidences

作为南岛语族起源假说的一部分，小米农业被学界认为可能在新石器时代晚期随着中国东南沿海的南岛语族先民一起向太平洋岛屿扩散。然而，作为这一扩散链条上关键一环的福建地区长期缺乏有关粟作农业的确凿证据。 在该文中，研究者综合运用植物考古、骨胶原碳、氮稳定同位素分析和碳十四年代学方法，揭示了福建地区新石器时代晚期小米农业的发展状况。除此之外，研究团队还根据从昙石山到屏风山不时同期动物骨胶原中碳、氮同位素比值的历时性变化，考察了人类对海洋性资源依赖程度的变化。 文章第一作者和通讯作者葛威副教授强调本项研究是团队合作的结果。参与研究的除了我校历史系师生，还有来自福建博物院、美国丹佛艺术博物馆、我校化学化工学院、环境与生态学院以及国家海洋局第三研究所的研究人员，充分显示了考古学研究的跨学科特点。【Abstract】The spread of millet agriculture to southeast China is critical to understanding the region’s economic pattern and its potential impact on the proposed initial expansion of proto-Austronesians. In this study, we present new multidisciplinary evidence for the development of millet agriculture from three Neolithic sites in Fujian Province, China: Hulushan, Pingfengshan and Huangguashan. The carbonized seeds from Hulushan indicate the existence of millet agriculture around 3842-3649 cal. BP. Meanwhile, we tested stable carbon and nitrogen isotope ratios of faunal remains (n=22) from Pingfengshan and Huangguashan shell midden sites in a coastal area of Fujian. The stable isotope results for pigs (δ15N values range from 4.9 to 11.2‰, and δ13C values range from -24.1 to -11.2‰) show significant variations, suggesting that these pigs were fed different foods, including C3 plants, C4 plants and marine resources. Specifically, two samples of pig collagen with strong millet signals were directly dated to about 4000-3600 cal. BP. These new findings provide substantial evidence for a new understanding of the development of millet agriculture in Southeast China.This research was supported by the National Social Science Foundation of China (No.18BKG002). We thank Liu Xinyi from the Department of Anthropology of Washington University in St. Louis for valuable discussions

A metabolomic investigation of the effects of metal pollution in oysters Crassostrea hongkongensis

Metal pollution has been of great concern in the estuaries in Southern China. In this study, metabolic differences between oysters Crassostrea hongkongensis from clean and metal-polluted sites were characterized using NMR-based metabolomics. We collected oyster samples from one clean (Jiuzhen) and two metal polluted sites (Baijiao and Fugong). The metal concentrations in oyster gills indicated that both the Baijiao and Fugong sites were severely polluted by several metals, including Cr, Ni, Cu, Zn, Ag, Cd and Pb. In particular, Cu and Zn were the major contaminants from the Baijiao and Fugong sites. Compared with those oysters from the clean site (JZ), metal pollution in BJ and FG induced disturbances in osmotic regulation and energy metabolism via different metabolic pathways, as indicated by different metabolic biomarkers. This study demonstrates that NMR-based metabolomics is a useful tool for characterizing metabolic responses induced by metal pollution. (C) 2014 Elsevier Ltd. All rights reserved.Metal pollution has been of great concern in the estuaries in Southern China. In this study, metabolic differences between oysters Crassostrea hongkongensis from clean and metal-polluted sites were characterized using NMR-based metabolomics. We collected oyster samples from one clean (Jiuzhen) and two metal polluted sites (Baijiao and Fugong). The metal concentrations in oyster gills indicated that both the Baijiao and Fugong sites were severely polluted by several metals, including Cr, Ni, Cu, Zn, Ag, Cd and Pb. In particular, Cu and Zn were the major contaminants from the Baijiao and Fugong sites. Compared with those oysters from the clean site (JZ), metal pollution in BJ and FG induced disturbances in osmotic regulation and energy metabolism via different metabolic pathways, as indicated by different metabolic biomarkers. This study demonstrates that NMR-based metabolomics is a useful tool for characterizing metabolic responses induced by metal pollution. (C) 2014 Elsevier Ltd. All rights reserved