To better understand the role of dissolved oxygen(DO) in affecting corrosion behavior of zirconium alloys,the Zr-0.85 Sn-0.16 Nb-0.37 Fe-0.18 Cr(wt.%) alloy was corroded in super-heated steam at 500℃ and 10.3 MPa und...To better understand the role of dissolved oxygen(DO) in affecting corrosion behavior of zirconium alloys,the Zr-0.85 Sn-0.16 Nb-0.37 Fe-0.18 Cr(wt.%) alloy was corroded in super-heated steam at 500℃ and 10.3 MPa under 1×10-6 DO and deaeration conditions.The microstructure of the alloy and oxide films was investigated by SEM,TEM,EDS and EBSD.Results show that the corrosion is aggravated under 1×10-6 DO.Compared with the deaeration condition,the oxide film is looser,and has more micro-cracks and more uneven inner surface under DO condition.For the oxide film forming under deaeration condition,the selected area diffraction(SAED) spots of planes(002)m,■ and(101)t are strong,while those of the(001)m and■ are weak.However,for the oxide film forming under DO condition,the SAED spots of planes(111)m,(200)m and(101)t are strong,while those of the(100)m and(110)m are weak.The higher DO content in super-heated steam accelerates the growth of oxide films,thus decreasing the corrosion resistance of zirconium alloys.展开更多
目的分析基于STEAM[S(science),T(technology),E(engineering),A(art),M(mathematics)]理念联合以问题为基础的教学法(problem base learning,PBL)在急诊医学教学中应用效果。方法选择2021年6月—2022年6月滨州医学院急诊科80名本临床...目的分析基于STEAM[S(science),T(technology),E(engineering),A(art),M(mathematics)]理念联合以问题为基础的教学法(problem base learning,PBL)在急诊医学教学中应用效果。方法选择2021年6月—2022年6月滨州医学院急诊科80名本临床医学专业实习生为研究对象,将其随机分为对照组、试验组,各40名。对照组接受传统教学,试验组接受基于STEAM理念联合PBL教学法。对比2组教学前后理论知识及实践操作考试成绩、实习生对教学的满意度、学习依从度及教学前后实习生职业特质评分。结果教学前,2组考核成绩对比,差异无统计学意义(P>0.05);教学3个月后,2组基础理论、实践操作考核成绩均明显提升,但试验组提升幅度更大,差异有统计学意义(P<0.001)。试验组实习生学习依从性(97.50%)高于对照组(85.00%),差异有统计学意义(P<0.001)。试验组教学方法、学术能力、带教态度管理质量评分高于对照组,差异有统计学意义(P<0.001)。教学前,2组实习生职业特质评分对比,差异无统计学意义(P>0.05);教学3个月后,试验组评分高于对照组,差异有统计学意义(P<0.001)。结论在急诊医学教学中,基于STEAM理念联合PBL教学法有利于提升实习生的综合能力,提高理论实践成绩和学习依从性。展开更多
基金Projects(51871141,51471102)supported by the National Natural Science Foundation of China
文摘To better understand the role of dissolved oxygen(DO) in affecting corrosion behavior of zirconium alloys,the Zr-0.85 Sn-0.16 Nb-0.37 Fe-0.18 Cr(wt.%) alloy was corroded in super-heated steam at 500℃ and 10.3 MPa under 1×10-6 DO and deaeration conditions.The microstructure of the alloy and oxide films was investigated by SEM,TEM,EDS and EBSD.Results show that the corrosion is aggravated under 1×10-6 DO.Compared with the deaeration condition,the oxide film is looser,and has more micro-cracks and more uneven inner surface under DO condition.For the oxide film forming under deaeration condition,the selected area diffraction(SAED) spots of planes(002)m,■ and(101)t are strong,while those of the(001)m and■ are weak.However,for the oxide film forming under DO condition,the SAED spots of planes(111)m,(200)m and(101)t are strong,while those of the(100)m and(110)m are weak.The higher DO content in super-heated steam accelerates the growth of oxide films,thus decreasing the corrosion resistance of zirconium alloys.
文摘目的分析基于STEAM[S(science),T(technology),E(engineering),A(art),M(mathematics)]理念联合以问题为基础的教学法(problem base learning,PBL)在急诊医学教学中应用效果。方法选择2021年6月—2022年6月滨州医学院急诊科80名本临床医学专业实习生为研究对象,将其随机分为对照组、试验组,各40名。对照组接受传统教学,试验组接受基于STEAM理念联合PBL教学法。对比2组教学前后理论知识及实践操作考试成绩、实习生对教学的满意度、学习依从度及教学前后实习生职业特质评分。结果教学前,2组考核成绩对比,差异无统计学意义(P>0.05);教学3个月后,2组基础理论、实践操作考核成绩均明显提升,但试验组提升幅度更大,差异有统计学意义(P<0.001)。试验组实习生学习依从性(97.50%)高于对照组(85.00%),差异有统计学意义(P<0.001)。试验组教学方法、学术能力、带教态度管理质量评分高于对照组,差异有统计学意义(P<0.001)。教学前,2组实习生职业特质评分对比,差异无统计学意义(P>0.05);教学3个月后,试验组评分高于对照组,差异有统计学意义(P<0.001)。结论在急诊医学教学中,基于STEAM理念联合PBL教学法有利于提升实习生的综合能力,提高理论实践成绩和学习依从性。
