Element parameters including volume filled ratio,surface dimensionless distance,and surface filled ratio for DFDM(direct finite difference method)were proposed to describe shape and location of free surfaces in castin...Element parameters including volume filled ratio,surface dimensionless distance,and surface filled ratio for DFDM(direct finite difference method)were proposed to describe shape and location of free surfaces in casting mold filling processes.A mathematical model of the filling process was proposed specially considering the mass,momentum and heat transfer in the vicinity of free surfaces.Furthermore,a method for gas entrapment was established by tracking flow of entrapped gas.The model and method were applied to practical ADC1 high pressure die castings.The gas entrapment prediction was compared with the fraction and maximum size of porosities in the different casting parts.The comparison shows validity of the proposed model and method.The study indicates that final porosities in high pressure die castings are dependent on both gas entrapment during mold filling process and pressure transfer within solidification period.展开更多
This study aimed at determining the effects of Angelica sinensis(AS) on urinary metabolites in blood deficiency mice and exploring its replenishing blood mechanism. Gas chromatography–mass spectrometry(GC-MS) was app...This study aimed at determining the effects of Angelica sinensis(AS) on urinary metabolites in blood deficiency mice and exploring its replenishing blood mechanism. Gas chromatography–mass spectrometry(GC-MS) was applied to detect metabolites in the urine samples in different collection periods. Principal component analysis(PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA) were used to investigate the differences in metabolic profiles among control group(CG), blood deficiency model group(MG), AS groups, and Colla Corii Asini group(CCAG). The potential biomarkers were identified based on the variable importance in the projection(VIP), T-test, and National Institute of Standards and Technology(NIST) and mass spectra library. The metabolites were analyzed using metabolomics pathway analysis(Met PA) to build the metabolic pathways. Our results indicated that, on the seventh day, the levels of glucose, lactic acid, pyruvic acid, alanine, acetoacetic acid, and citric acid changed significantly in blood deficiency mice. However, these metabolic deviations came to closer to normal levels after AS intervention. The reversing blood-deficiency mechanism of AS might involve regulating synthesis and degradation of ketone bodies, Pyruvate metabolism, TCA cycle, and Glycolysis / Gluconeogenesis. In conclusion, metabonomics is a robust and promising means for the identification of biomarkers and elucidation of the mechanisms of a disease, thereby highlighting its importance in drug discovery.展开更多
基金Project(50975093)supported by the National Natural Science Foundation of ChinaProject(08-0209)supported by New Century Excellent Talent in University,Ministry of Education,ChinaProject(2009ZM0283)supported by the Fundamental Research Funds for the Central Universities,China
文摘Element parameters including volume filled ratio,surface dimensionless distance,and surface filled ratio for DFDM(direct finite difference method)were proposed to describe shape and location of free surfaces in casting mold filling processes.A mathematical model of the filling process was proposed specially considering the mass,momentum and heat transfer in the vicinity of free surfaces.Furthermore,a method for gas entrapment was established by tracking flow of entrapped gas.The model and method were applied to practical ADC1 high pressure die castings.The gas entrapment prediction was compared with the fraction and maximum size of porosities in the different casting parts.The comparison shows validity of the proposed model and method.The study indicates that final porosities in high pressure die castings are dependent on both gas entrapment during mold filling process and pressure transfer within solidification period.
基金financially supported by the Natural Science Foundation of China(No.31272600)
文摘This study aimed at determining the effects of Angelica sinensis(AS) on urinary metabolites in blood deficiency mice and exploring its replenishing blood mechanism. Gas chromatography–mass spectrometry(GC-MS) was applied to detect metabolites in the urine samples in different collection periods. Principal component analysis(PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA) were used to investigate the differences in metabolic profiles among control group(CG), blood deficiency model group(MG), AS groups, and Colla Corii Asini group(CCAG). The potential biomarkers were identified based on the variable importance in the projection(VIP), T-test, and National Institute of Standards and Technology(NIST) and mass spectra library. The metabolites were analyzed using metabolomics pathway analysis(Met PA) to build the metabolic pathways. Our results indicated that, on the seventh day, the levels of glucose, lactic acid, pyruvic acid, alanine, acetoacetic acid, and citric acid changed significantly in blood deficiency mice. However, these metabolic deviations came to closer to normal levels after AS intervention. The reversing blood-deficiency mechanism of AS might involve regulating synthesis and degradation of ketone bodies, Pyruvate metabolism, TCA cycle, and Glycolysis / Gluconeogenesis. In conclusion, metabonomics is a robust and promising means for the identification of biomarkers and elucidation of the mechanisms of a disease, thereby highlighting its importance in drug discovery.
