ZE20(Mg-2Zn-0.2Ce)^2 is a new wrought magnesium alloy with improved extrudability and mechanical properties[1].To understand the constitutive behavior and workability of this new alloy,Gleeble thermomechanical testing...ZE20(Mg-2Zn-0.2Ce)^2 is a new wrought magnesium alloy with improved extrudability and mechanical properties[1].To understand the constitutive behavior and workability of this new alloy,Gleeble thermomechanical testing has been carried out in this study.The flow stress behavior of ZE20 was investigated between 250℃–450℃ and 10^–3 s^–1–1.0 s^–1 in isothermal compression.Constitutive descriptions of the flow stress are provided.A new general approach at application of the extended Ludwik equation is demonstrated and was found to be more accurate than the hyperbolic sine Arrhenius model while having a similar number of model constants.Processing maps were developed based on the experimental results and are verified with microstructural investigation.A region of safe processing with non-basal texture and high activity of dynamic recrystallization(DRX)was found between 375℃ and 450℃,from 10^–1 s^–1 to 10^–2.5 s^–1.A region of potentially safe processing with annealing that is associated with shear band nucleation of non-basal grains was identified for temperatures as low as 300℃ and rates as high as 10^–1 s^–1.展开更多
In this paper, the magnetic and transport properties in ABO3-type perovskite-like manganites as functions of the structure have been discussed from the viewpoints of A- and B-site doping, respectively. For the A-site ...In this paper, the magnetic and transport properties in ABO3-type perovskite-like manganites as functions of the structure have been discussed from the viewpoints of A- and B-site doping, respectively. For the A-site doping, two simple parameters, tolerance factor t and variance of the A-cation radius distribution s, can be used to characterize the magnetic/resistive phase diagram. For the B-site doping, the case is complicated due to the direct action to the center of double exchange. However, the dopant-size-induced local strain effect plays an important role in the physical properties besides the size mismatch between A- and B-site ions.展开更多
Introduction: Every year worldwide, the WHO estimates that nearly one million people take their own lives, the equivalent of one suicide occurring every 40 seconds, despite the fact that this harm is preventable. Obje...Introduction: Every year worldwide, the WHO estimates that nearly one million people take their own lives, the equivalent of one suicide occurring every 40 seconds, despite the fact that this harm is preventable. Objective: The aim of this study is to investigate the risk of suicide in the general population in the commune of Parakou in 2022. Methods: Descriptive cross-sectional study conducted from December 2021 to December 2022. Sampling was probabilistic, using the WHO cluster sampling technique. Results: A total of 582 subjects were surveyed, of whom 99 (17.01%) were at risk of suicide (low (7.6%), moderate (5.7%) and high (3.8%)). Evaluation of suicidal behaviors revealed suicidal ideation (15.12%), suicidal planning (4.46%), suicide attempts (3.78%) and suicidal equivalents (6.90%). After multivariate analysis, the following were statically associated with suicidal risk: wet nurse status of less than one month (p = 0.003), family history of suicide attempt (p = 0.004), lack of affection from parents or guardians (p = 0.044), poor relationship with partner (p = 0.033) and depression (p = 0.001). Conclusion: Approximately one person in five is at risk of suicide at the end of this study. There is every interest to implement effective preventive measures at national level.展开更多
基金This work is partially supported by the United States Automotive Materials Partnership(USAMP).
文摘ZE20(Mg-2Zn-0.2Ce)^2 is a new wrought magnesium alloy with improved extrudability and mechanical properties[1].To understand the constitutive behavior and workability of this new alloy,Gleeble thermomechanical testing has been carried out in this study.The flow stress behavior of ZE20 was investigated between 250℃–450℃ and 10^–3 s^–1–1.0 s^–1 in isothermal compression.Constitutive descriptions of the flow stress are provided.A new general approach at application of the extended Ludwik equation is demonstrated and was found to be more accurate than the hyperbolic sine Arrhenius model while having a similar number of model constants.Processing maps were developed based on the experimental results and are verified with microstructural investigation.A region of safe processing with non-basal texture and high activity of dynamic recrystallization(DRX)was found between 375℃ and 450℃,from 10^–1 s^–1 to 10^–2.5 s^–1.A region of potentially safe processing with annealing that is associated with shear band nucleation of non-basal grains was identified for temperatures as low as 300℃ and rates as high as 10^–1 s^–1.
基金This work was supported by MOST of China (G19980613) NSFC (Nos. 29831010 & 20023005)+1 种基金 the Post-Doctoral Foundation of Chinathe Founder Foundation of PKU Corresponding author.
文摘In this paper, the magnetic and transport properties in ABO3-type perovskite-like manganites as functions of the structure have been discussed from the viewpoints of A- and B-site doping, respectively. For the A-site doping, two simple parameters, tolerance factor t and variance of the A-cation radius distribution s, can be used to characterize the magnetic/resistive phase diagram. For the B-site doping, the case is complicated due to the direct action to the center of double exchange. However, the dopant-size-induced local strain effect plays an important role in the physical properties besides the size mismatch between A- and B-site ions.
文摘Introduction: Every year worldwide, the WHO estimates that nearly one million people take their own lives, the equivalent of one suicide occurring every 40 seconds, despite the fact that this harm is preventable. Objective: The aim of this study is to investigate the risk of suicide in the general population in the commune of Parakou in 2022. Methods: Descriptive cross-sectional study conducted from December 2021 to December 2022. Sampling was probabilistic, using the WHO cluster sampling technique. Results: A total of 582 subjects were surveyed, of whom 99 (17.01%) were at risk of suicide (low (7.6%), moderate (5.7%) and high (3.8%)). Evaluation of suicidal behaviors revealed suicidal ideation (15.12%), suicidal planning (4.46%), suicide attempts (3.78%) and suicidal equivalents (6.90%). After multivariate analysis, the following were statically associated with suicidal risk: wet nurse status of less than one month (p = 0.003), family history of suicide attempt (p = 0.004), lack of affection from parents or guardians (p = 0.044), poor relationship with partner (p = 0.033) and depression (p = 0.001). Conclusion: Approximately one person in five is at risk of suicide at the end of this study. There is every interest to implement effective preventive measures at national level.
基金Financial supports from China Scholarship Council and Helmholtz Association of German Research Centers scholarship(No.2010821213) for Wang’s Ph D study in Helmholtz-Zentrum Geesthacht(HZG) are gratefully acknowledged
