Graphene is one of the most promising thermal protection materials for high-speed aircraft due to its lightweight and excellent thermophysical properties. At high Mach numbers, the extremely high postshock temperature would dissociate the surrounding air into a mixture of atomic and molecular components in a highly thermochemical nonequilibrium state, which greatly affects the subsequent thermal chemical reactions of the graphene interface. Through establishing a reactive gas-solid interface model, the reactive molecular dynamics method is employed in this study to reveal the influences of the thermochemical nonequilibrium gas mixture on the thermal oxidation and nitridation mechanisms of graphene sheet.
View Article and Find Full Text PDFThe transfer of Pb from the soil to crops is a serious food hygiene security problem in China because of industrial, agricultural, and historical contamination. In this study, the characteristics of exogenous Pb transfer from 17 Chinese soils to a popular wheat variety (Xiaoyan 22) were investigated. In addition, bioaccumulation prediction models of Pb in grain were obtained based on soil properties.
View Article and Find Full Text PDFEcotoxicol Environ Saf
August 2016
The application of current Chinese agriculture soil quality standards fails to evaluate the land utilization functions appropriately due to the diversity of soil properties and plant species. Therefore, the standards should be amended. A greenhouse experiment was conducted to investigate arsenic (As) enrichment in various soils from 18 Chinese provinces in parallel with As transfer to 8 wheat varieties.
View Article and Find Full Text PDFEcotoxicol Environ Saf
March 2015
At present, soil quality standards for agriculture have not been improved for many years and are applied uniformly for a diverse variety of crops and different soil types, not fully considering the effects of soil properties on cadmium (Cd) uptake via soil-plant transfer. In this study, the characteristics of Cd transfer from soil to eight wheat varieties were investigated, and the results showed that Xiaoyan 22 was moderately sensitive to Cd. Upon growing Xiaoyan 22 in 18 different Chinese soils, we studied the major controlling factors of Cd transfer and constructed a bioaccumulation prediction model from the soil properties.
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