颈椎骨折或脱位(Vertebral fracture or luxation)是指颈椎和支撑性软组织结构的外伤或病理性破裂导致椎骨骨折或脱位,病因常见于外力冲击所致,而一些不常见因素包括牵拉、营养代谢病或肿瘤疾病等导致骨结构异常^([1])。寰枢椎脱位或骨...颈椎骨折或脱位(Vertebral fracture or luxation)是指颈椎和支撑性软组织结构的外伤或病理性破裂导致椎骨骨折或脱位,病因常见于外力冲击所致,而一些不常见因素包括牵拉、营养代谢病或肿瘤疾病等导致骨结构异常^([1])。寰枢椎脱位或骨折往往发生于颈颅联合与后段颈椎之间,因此枢椎成为压力受力点,而作用于颈椎的外伤力量最终到达枢椎,对寰枢椎关节稳定性产生破坏,当抵抗这些压力的脊椎支持结构受损导致骨折或脱位.展开更多
The microstructure evolutions of two A1-Zn-Mg alloys, one of which was alloyed with Sc and Zr, and the kinetics of A13（SCl-xZrx） precipitates in the A1-Zn-Mg alloy during homogenization were investigated. Both alloy...The microstructure evolutions of two A1-Zn-Mg alloys, one of which was alloyed with Sc and Zr, and the kinetics of A13（SCl-xZrx） precipitates in the A1-Zn-Mg alloy during homogenization were investigated. Both alloys under as-cast condition with supersaturated, non-equilibrium T（Mg32（A1, Zn）49） phase and impurities phase were displayed. When the homogenization temperatures are below 350 ~C, Zn and Mg atoms precipitate from matrix; however, when the temperatures are above 400 ~C, T phase dissolves into matrix, enhancing solid-solution strengthening. Kinetics of A13（Scl.xZrx） precipitates was studied based on Jmat Pro software calculation and the difference values between the hardness of the two alloys in each homogenization condition. The calculations predict that the Sc and Zr solubilities in ct-A1 decline with the presence of Mg and Zn. Investigation of the difference values reveals that when the temperature is between 300 ~C and 350 ~C, the nucleation rate of A13（Sc1-xZrx） precipitates is the highest and the strengthening effect from A13（SCl_xZrx） precipitates is the best. After homogenization at 470℃ for 12 h, non-equilibrium T phase disappears, while impurity phase remains. The mean diameter of A13（Scl_xZrx） precipitates is around 18 urn. Ideas about better fulfilling the potentials of Sc and Zr were proposed at last.展开更多
文摘颈椎骨折或脱位(Vertebral fracture or luxation)是指颈椎和支撑性软组织结构的外伤或病理性破裂导致椎骨骨折或脱位,病因常见于外力冲击所致,而一些不常见因素包括牵拉、营养代谢病或肿瘤疾病等导致骨结构异常^([1])。寰枢椎脱位或骨折往往发生于颈颅联合与后段颈椎之间,因此枢椎成为压力受力点,而作用于颈椎的外伤力量最终到达枢椎,对寰枢椎关节稳定性产生破坏,当抵抗这些压力的脊椎支持结构受损导致骨折或脱位.
基金Project(JPPT-115-2-948) supported by the National Civilian Matched Project of China
文摘The microstructure evolutions of two A1-Zn-Mg alloys, one of which was alloyed with Sc and Zr, and the kinetics of A13（SCl-xZrx） precipitates in the A1-Zn-Mg alloy during homogenization were investigated. Both alloys under as-cast condition with supersaturated, non-equilibrium T（Mg32（A1, Zn）49） phase and impurities phase were displayed. When the homogenization temperatures are below 350 ~C, Zn and Mg atoms precipitate from matrix; however, when the temperatures are above 400 ~C, T phase dissolves into matrix, enhancing solid-solution strengthening. Kinetics of A13（Scl.xZrx） precipitates was studied based on Jmat Pro software calculation and the difference values between the hardness of the two alloys in each homogenization condition. The calculations predict that the Sc and Zr solubilities in ct-A1 decline with the presence of Mg and Zn. Investigation of the difference values reveals that when the temperature is between 300 ~C and 350 ~C, the nucleation rate of A13（Sc1-xZrx） precipitates is the highest and the strengthening effect from A13（SCl_xZrx） precipitates is the best. After homogenization at 470℃ for 12 h, non-equilibrium T phase disappears, while impurity phase remains. The mean diameter of A13（Scl_xZrx） precipitates is around 18 urn. Ideas about better fulfilling the potentials of Sc and Zr were proposed at last.
