To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator a...To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator at temperatures of 380-440℃and strain rates of 0.05-1 s^(−1).The Johnson-Cook model,Hensel-Spittel model,strain-compensated Arrhenius model,and critical fracture strain model were established.Results show that through the evaluation of the models using the correlation coefficient(R)and the average absolute relative error,the strain-compensated Arrhenius model can represent the flow behavior of the alloy more accurately.Shear bands are more pronounced in the as-homogenized specimens,whereas dynamic recrystallization is predominantly observed in as-rolled specimens.Fracture morphology analysis reveals that a mixed fracture mechanism is prevalent in the as-homogenized specimen,whereas a ductile fracture mechanism is predominant in the as-rolled specimen.The processing maps indicate that the unstable region is reduced in the as-rolled specimens compared with that in the as-homogenized specimens.The optimal hot working windows for the as-homogenized and as-rolled specimens are determined as 410-440℃/0.14-1 s^(−1)and 380-400℃/0.05-0.29 s^(−1),respectively.展开更多
目的探究双相情感障碍(bipolar disorder,BD)伴精神病性症状患者基于电子病历的生物标志物,开发具有可解释性的风险预测模型,为识别高危人群和及时临床干预提供决策支持。方法使用医院电子病历系统收集四川大学华西医院收治的2352名双...目的探究双相情感障碍(bipolar disorder,BD)伴精神病性症状患者基于电子病历的生物标志物,开发具有可解释性的风险预测模型,为识别高危人群和及时临床干预提供决策支持。方法使用医院电子病历系统收集四川大学华西医院收治的2352名双相情感障碍患者,并在该人群基础上分为双相抑郁(bipolar disorder depression,BDD)和双相躁狂(bipolar disorder mania,BDM)两个亚组。使用逻辑回归(logistic regression,LR)算法训练和验证预测模型,并使用可解释方法分析每个特征对个体的贡献及特征对特定目标预测决策的影响。结果各逻辑回归模型在BD、BDD、BDM三组中表现良好,曲线下面积(area under the curve,AUC)均大于81.6%。核心预测特征包括血小板分布宽度(platelet distribution width,PDW)、纤维蛋白原(fibrinogen,FIB)、大血小板比率(platelet large cell ratio,P-LCR)、活化部分凝血活酶时间(activated partial thromboplastin time,APTT)、凝血酶原时间(prothrombin time,PT)、甘油三酯(triglyceride,TG)。逻辑回归模型提供了良好的可解释性,并结合了列线图进行直观的风险量化和个体化预测。结论通过逻辑回归模型能快速简便筛出伴有精神病性症状的BD患者,双相抑郁组和双相躁狂组血液标志物变化模式的差异丰富了对其潜在病理生理机制的理解,强调了考虑亚型对于干预管理患者的重要性。展开更多
文摘To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator at temperatures of 380-440℃and strain rates of 0.05-1 s^(−1).The Johnson-Cook model,Hensel-Spittel model,strain-compensated Arrhenius model,and critical fracture strain model were established.Results show that through the evaluation of the models using the correlation coefficient(R)and the average absolute relative error,the strain-compensated Arrhenius model can represent the flow behavior of the alloy more accurately.Shear bands are more pronounced in the as-homogenized specimens,whereas dynamic recrystallization is predominantly observed in as-rolled specimens.Fracture morphology analysis reveals that a mixed fracture mechanism is prevalent in the as-homogenized specimen,whereas a ductile fracture mechanism is predominant in the as-rolled specimen.The processing maps indicate that the unstable region is reduced in the as-rolled specimens compared with that in the as-homogenized specimens.The optimal hot working windows for the as-homogenized and as-rolled specimens are determined as 410-440℃/0.14-1 s^(−1)and 380-400℃/0.05-0.29 s^(−1),respectively.
文摘目的探究双相情感障碍(bipolar disorder,BD)伴精神病性症状患者基于电子病历的生物标志物,开发具有可解释性的风险预测模型,为识别高危人群和及时临床干预提供决策支持。方法使用医院电子病历系统收集四川大学华西医院收治的2352名双相情感障碍患者,并在该人群基础上分为双相抑郁(bipolar disorder depression,BDD)和双相躁狂(bipolar disorder mania,BDM)两个亚组。使用逻辑回归(logistic regression,LR)算法训练和验证预测模型,并使用可解释方法分析每个特征对个体的贡献及特征对特定目标预测决策的影响。结果各逻辑回归模型在BD、BDD、BDM三组中表现良好,曲线下面积(area under the curve,AUC)均大于81.6%。核心预测特征包括血小板分布宽度(platelet distribution width,PDW)、纤维蛋白原(fibrinogen,FIB)、大血小板比率(platelet large cell ratio,P-LCR)、活化部分凝血活酶时间(activated partial thromboplastin time,APTT)、凝血酶原时间(prothrombin time,PT)、甘油三酯(triglyceride,TG)。逻辑回归模型提供了良好的可解释性,并结合了列线图进行直观的风险量化和个体化预测。结论通过逻辑回归模型能快速简便筛出伴有精神病性症状的BD患者,双相抑郁组和双相躁狂组血液标志物变化模式的差异丰富了对其潜在病理生理机制的理解,强调了考虑亚型对于干预管理患者的重要性。
