The dynamic mechanical properties of Fe-30Mn-3Si-4A1 twinning induced plasticity （TWIP） steel were studied by the split-Hopkinson pressure bar （SHPB） at temperatures of 298-1073 K and strain rates of 700, 2500, an...The dynamic mechanical properties of Fe-30Mn-3Si-4A1 twinning induced plasticity （TWIP） steel were studied by the split-Hopkinson pressure bar （SHPB） at temperatures of 298-1073 K and strain rates of 700, 2500, and 5000 s-1. The TWIP steel indicates strain rate hardening effect between 700 and 2500 s-1, but it shows strain rate softening effect between 2500 and 5000 s-1. In addition, the strain rate softening effect enhances with an increase in deformation temperature. After deformation, the microstructures were studied by optical microscopy （OM）. It is shown that the deformation bands become more convergence, a part of which become interwoven with an increase in strain rate, and the dynamic recovery and recrystallization are enhanced with an increase in both temperature and strain rate.展开更多
Background： Despite the rapid growth in the incidence of acute myocardial infarction （AMI） in China, there is limited information about patients＇ experiences after AMI hospitalization, especially on long-tern1 adv...Background： Despite the rapid growth in the incidence of acute myocardial infarction （AMI） in China, there is limited information about patients＇ experiences after AMI hospitalization, especially on long-tern1 adverse events and patient-reported outcomes （PROs）. Methods： The China Patient-centered Evaluative Assessment of Cardiac Events （PEACE）-Prospective AMI Study will enroll 4000 consecutive AM I patients from 53 diverse hospitals across China and follow them longitudinally for 12 months to docunlent their treatment, recovery, and outcomes. Details of patients＇ medical history, treatment, and in-hospital outcomes are abstracted from medical charts. Comprehensive baseline interviews are being conducted to characterize patient demographics, risk factors, presentation, and healthcare utilization. As part of these interviews, validated instruments are administered to measure PROs, including quality of life, symptoms, mood, cognition, and sexual activity. Follow-up interviews, measuring PROs, medication adherence, risk factor control, and collecting hospitalization events are conducted at 1, 6, and 12 months after discharge. Supporting documents for potential outcomes are collected for adjudication by clinicians at the National Coordinating Center. Blood and urine samples are also obtained at baseline, 1 - and 12-month follow-up. In addition, we are conducting a survey of participating hospitals to characterize their organizational characteristics. Conclusion： The China PEACE-Prospective AMI study will be uniquely positioned to generate new information regarding patient＇s experiences and outcomes alter AMI in China and seiwe as a foundation for quality improveinent activities.展开更多
As twinning-induced plasticity （TWIP） steel is one potential material for shaped charge liner due to the combination of high strength and high plasticity, deformation mechanism at high strain rate and high temperatu...As twinning-induced plasticity （TWIP） steel is one potential material for shaped charge liner due to the combination of high strength and high plasticity, deformation mechanism at high strain rate and high temperature is required to study. Compression experiments of Fe 30Mn-3Si-4Al TWIP steel were conducted using a Gleeble 1500 thermal simulation machine and a split-Hopkinson pressure bar （SHPB） between 298 and 1073 K at strain rates of 10 3 and 700 s-1 , respectively. Microstructures were observed using optical microscopy （OM） and transmission e- lectron microscopy （TEM）. Results show that flow stress and densities of deformation twins and dislocations de crease with increasing deformation temperature at strain rates of 10 3 and 700 s -1. The stack fault energy （SFE） values （Г） of Fe-30Mn-3Si-4Al TWIP steel at different temperatures were calculated using thermodynamic data. Based on corresponding microstructures, it can he inferred that at 700 s -1 , twinning is the main deformation mecha- nism at 298-573 K for 30 mJ/m2≤Г≤63 mJ/m2 , while dislocation gliding is the main deformation mechanism above 1 073 K for Г≥145 mJ/m2. In addition, with increasing strain rate from 10-3 to 700 s -1 , the SFE range of twinning is enlarged and the SEF value of twinning becomes higher.展开更多
文摘The dynamic mechanical properties of Fe-30Mn-3Si-4A1 twinning induced plasticity （TWIP） steel were studied by the split-Hopkinson pressure bar （SHPB） at temperatures of 298-1073 K and strain rates of 700, 2500, and 5000 s-1. The TWIP steel indicates strain rate hardening effect between 700 and 2500 s-1, but it shows strain rate softening effect between 2500 and 5000 s-1. In addition, the strain rate softening effect enhances with an increase in deformation temperature. After deformation, the microstructures were studied by optical microscopy （OM）. It is shown that the deformation bands become more convergence, a part of which become interwoven with an increase in strain rate, and the dynamic recovery and recrystallization are enhanced with an increase in both temperature and strain rate.
文摘Background： Despite the rapid growth in the incidence of acute myocardial infarction （AMI） in China, there is limited information about patients＇ experiences after AMI hospitalization, especially on long-tern1 adverse events and patient-reported outcomes （PROs）. Methods： The China Patient-centered Evaluative Assessment of Cardiac Events （PEACE）-Prospective AMI Study will enroll 4000 consecutive AM I patients from 53 diverse hospitals across China and follow them longitudinally for 12 months to docunlent their treatment, recovery, and outcomes. Details of patients＇ medical history, treatment, and in-hospital outcomes are abstracted from medical charts. Comprehensive baseline interviews are being conducted to characterize patient demographics, risk factors, presentation, and healthcare utilization. As part of these interviews, validated instruments are administered to measure PROs, including quality of life, symptoms, mood, cognition, and sexual activity. Follow-up interviews, measuring PROs, medication adherence, risk factor control, and collecting hospitalization events are conducted at 1, 6, and 12 months after discharge. Supporting documents for potential outcomes are collected for adjudication by clinicians at the National Coordinating Center. Blood and urine samples are also obtained at baseline, 1 - and 12-month follow-up. In addition, we are conducting a survey of participating hospitals to characterize their organizational characteristics. Conclusion： The China PEACE-Prospective AMI study will be uniquely positioned to generate new information regarding patient＇s experiences and outcomes alter AMI in China and seiwe as a foundation for quality improveinent activities.
文摘As twinning-induced plasticity （TWIP） steel is one potential material for shaped charge liner due to the combination of high strength and high plasticity, deformation mechanism at high strain rate and high temperature is required to study. Compression experiments of Fe 30Mn-3Si-4Al TWIP steel were conducted using a Gleeble 1500 thermal simulation machine and a split-Hopkinson pressure bar （SHPB） between 298 and 1073 K at strain rates of 10 3 and 700 s-1 , respectively. Microstructures were observed using optical microscopy （OM） and transmission e- lectron microscopy （TEM）. Results show that flow stress and densities of deformation twins and dislocations de crease with increasing deformation temperature at strain rates of 10 3 and 700 s -1. The stack fault energy （SFE） values （Г） of Fe-30Mn-3Si-4Al TWIP steel at different temperatures were calculated using thermodynamic data. Based on corresponding microstructures, it can he inferred that at 700 s -1 , twinning is the main deformation mecha- nism at 298-573 K for 30 mJ/m2≤Г≤63 mJ/m2 , while dislocation gliding is the main deformation mechanism above 1 073 K for Г≥145 mJ/m2. In addition, with increasing strain rate from 10-3 to 700 s -1 , the SFE range of twinning is enlarged and the SEF value of twinning becomes higher.
