Effects of spherical quasi-crystal contained in Mg-Zn-Y-Mn master alloy on the microstructure and as-cast mechanical properties of ZA155 high zinc magnesium alloy have been investigated by means of optical microscopy,...Effects of spherical quasi-crystal contained in Mg-Zn-Y-Mn master alloy on the microstructure and as-cast mechanical properties of ZA155 high zinc magnesium alloy have been investigated by means of optical microscopy,XRD,SEM,EDS,tensile test,impact test and hardness test.Experimental results show that the addition of spherical quasi-crystal contained in the Mg-Zn-Y-Mn master alloy into the ZA155 high zinc magnesium alloy resulted in grain refinement of the matrix,changing the morphologies of φ-Al2Mg5Zn2 phase and τ-Mg32(Al,Zn)49 phase from continuous net-like structures to discontinuous strip-like structure and blocky one,respectively.In the present research,the best comprehensive mechanical properties of reinforced ZA155 high zinc magnesium alloy has been obtained when 5.0wt% spherical quasi-crystal was introduced from the Mg-Zn-Y-Mn master alloy into the target alloy system.In such case,the room-temperature tensile strength reached 207 MPa,about 23% higher than that of the base alloy;the impact toughness peaked at 5.5 J/cm2,about 40% higher than that of the base alloy;and the elevated-temperature tensile strength reached 203 MPa,indicating improved heat resistance.展开更多
目的评价适龄儿童一款水痘减毒活疫苗(Varicella attenuated live vaccine,VarV)接种不良反应发生率。方法在安徽省5个地市预防接种门诊招募1-12岁健康儿童,观察接种1剂次VarV后0-30 d不良反应,分析不良反应发生率。结果本研究共纳入916...目的评价适龄儿童一款水痘减毒活疫苗(Varicella attenuated live vaccine,VarV)接种不良反应发生率。方法在安徽省5个地市预防接种门诊招募1-12岁健康儿童,观察接种1剂次VarV后0-30 d不良反应,分析不良反应发生率。结果本研究共纳入9169例受试者,接种VarV后不良反应总发生率为1.09%(100例),其中局部反应、全身反应发生率分别为0.69%(63例)、0.46%(42例),各以接种部位疼痛(0.40%)和发热(0.26%)发生率最高,未发生3级/4级或严重不良反应和特殊关注不良事件。1-3岁、4-12岁受试者不良反应发生率分别为1.47%(64/4347)、0.75%(36/4822)(χ^(2)=11.16,P<0.001)。结论1-12岁健康儿童接种1剂次VarV后不良反应轻微,发生率在预期范围内。展开更多
基金supported by both the National Natural Science Foundation of China (No. 50571073)the Natural Science Foundation of Shanxi Province (No. 2009011028-3,20051052)
文摘Effects of spherical quasi-crystal contained in Mg-Zn-Y-Mn master alloy on the microstructure and as-cast mechanical properties of ZA155 high zinc magnesium alloy have been investigated by means of optical microscopy,XRD,SEM,EDS,tensile test,impact test and hardness test.Experimental results show that the addition of spherical quasi-crystal contained in the Mg-Zn-Y-Mn master alloy into the ZA155 high zinc magnesium alloy resulted in grain refinement of the matrix,changing the morphologies of φ-Al2Mg5Zn2 phase and τ-Mg32(Al,Zn)49 phase from continuous net-like structures to discontinuous strip-like structure and blocky one,respectively.In the present research,the best comprehensive mechanical properties of reinforced ZA155 high zinc magnesium alloy has been obtained when 5.0wt% spherical quasi-crystal was introduced from the Mg-Zn-Y-Mn master alloy into the target alloy system.In such case,the room-temperature tensile strength reached 207 MPa,about 23% higher than that of the base alloy;the impact toughness peaked at 5.5 J/cm2,about 40% higher than that of the base alloy;and the elevated-temperature tensile strength reached 203 MPa,indicating improved heat resistance.
文摘目的评价适龄儿童一款水痘减毒活疫苗(Varicella attenuated live vaccine,VarV)接种不良反应发生率。方法在安徽省5个地市预防接种门诊招募1-12岁健康儿童,观察接种1剂次VarV后0-30 d不良反应,分析不良反应发生率。结果本研究共纳入9169例受试者,接种VarV后不良反应总发生率为1.09%(100例),其中局部反应、全身反应发生率分别为0.69%(63例)、0.46%(42例),各以接种部位疼痛(0.40%)和发热(0.26%)发生率最高,未发生3级/4级或严重不良反应和特殊关注不良事件。1-3岁、4-12岁受试者不良反应发生率分别为1.47%(64/4347)、0.75%(36/4822)(χ^(2)=11.16,P<0.001)。结论1-12岁健康儿童接种1剂次VarV后不良反应轻微,发生率在预期范围内。