Ternary Zn-0.5A1-0.5Mg and quatemary Zn-0.5A1-0.5Mg-xBi （x = 0.1, 0.3 and 0.5） alloys were studied to evaluate the thermal and structural characteristics, mechanical properties, cytotoxicity and in vitro degradation...Ternary Zn-0.5A1-0.5Mg and quatemary Zn-0.5A1-0.5Mg-xBi （x = 0.1, 0.3 and 0.5） alloys were studied to evaluate the thermal and structural characteristics, mechanical properties, cytotoxicity and in vitro degradation behavior. Thermal analysis and microstructural observations showed that Zn-0.5A1-0.5Mg is composed of FCC-A1 ＋ HCP- Zn ＋ Mg2（Zn,A1）ll while a new phase a-Mg3Bi2 appeared after the addition of Bi to the Zn-0.5A1-0.5Mg ternary alloy. The results revealed that the quaternary Zn-A1-Mg-Bi alloys have higher tensile strength, elongation and hardness but slightly lower corrosion resistance than those of the temary Zn-AI-Mg alloy. Based on the MTT assay, the Zn-A1-Mg and Zn-A1-Mg-Bi alloys were found to be biocompatible, and thus, they can be considered for further investigation in an in vivo environment.展开更多
Numerical simulations have been carried out for laminar sinusoidal pulsating flow in a tube with smooth single constriction.A second-order finite volume method has been developed to solve the fluid flow governing equa...Numerical simulations have been carried out for laminar sinusoidal pulsating flow in a tube with smooth single constriction.A second-order finite volume method has been developed to solve the fluid flow governing equations on a nonstaggered non-orthogonal grid.The effects of the Reynolds number,the Womersley number,the pulsatile amplitude,the constriction ratio and the constriction length on fluid flow in constricted tube will be investigated.It will be demonstrated that the dynamic nature of the pulsating flow greatly depends on the frequency of the flow changes.It is observed that the peak wall vorticity seems to increase with the increase of Reynolds number,the pulsating amplitude and the constriction ratio.The peak values of instantaneous wall vorticity are not greatly affected by the variation of Womersly number.The constriction length does not put a significant impact on the flow instantaneous streamline behaviors compared with other parameters.However,the peak wall vorticity increases monotonically with the decrease of the constriction length.展开更多
文摘Ternary Zn-0.5A1-0.5Mg and quatemary Zn-0.5A1-0.5Mg-xBi （x = 0.1, 0.3 and 0.5） alloys were studied to evaluate the thermal and structural characteristics, mechanical properties, cytotoxicity and in vitro degradation behavior. Thermal analysis and microstructural observations showed that Zn-0.5A1-0.5Mg is composed of FCC-A1 ＋ HCP- Zn ＋ Mg2（Zn,A1）ll while a new phase a-Mg3Bi2 appeared after the addition of Bi to the Zn-0.5A1-0.5Mg ternary alloy. The results revealed that the quaternary Zn-A1-Mg-Bi alloys have higher tensile strength, elongation and hardness but slightly lower corrosion resistance than those of the temary Zn-AI-Mg alloy. Based on the MTT assay, the Zn-A1-Mg and Zn-A1-Mg-Bi alloys were found to be biocompatible, and thus, they can be considered for further investigation in an in vivo environment.
文摘Numerical simulations have been carried out for laminar sinusoidal pulsating flow in a tube with smooth single constriction.A second-order finite volume method has been developed to solve the fluid flow governing equations on a nonstaggered non-orthogonal grid.The effects of the Reynolds number,the Womersley number,the pulsatile amplitude,the constriction ratio and the constriction length on fluid flow in constricted tube will be investigated.It will be demonstrated that the dynamic nature of the pulsating flow greatly depends on the frequency of the flow changes.It is observed that the peak wall vorticity seems to increase with the increase of Reynolds number,the pulsating amplitude and the constriction ratio.The peak values of instantaneous wall vorticity are not greatly affected by the variation of Womersly number.The constriction length does not put a significant impact on the flow instantaneous streamline behaviors compared with other parameters.However,the peak wall vorticity increases monotonically with the decrease of the constriction length.
