The control of grain size in superalloys is critical in the manufacture of gas turbine blades.The aim of the present research is to provide the technology for producing complicated hollow turbine blades with fine surf...The control of grain size in superalloys is critical in the manufacture of gas turbine blades.The aim of the present research is to provide the technology for producing complicated hollow turbine blades with fine surface grains and better comprehensive mechanical properties.By melt superheating treatment and coating the internal surfaces of shell mould using a cobalt aluminate-bearing coating material,the in-uence of cobalt aluminate as inoculant on the surface grain sizes of turbine blade was studied with addition of cobalt aluminate:0,35%,45%-65% and 100% respectively.At the same time,the effects of cooling circumstances of the blades on surface grain sizes were also experimented under the same addition of cobalt aluminate.The results showed that the melt superheating treatment plays a significant role in the grain size and carbide morphology;and fine surface grains were obtained when the internal surfaces of shell mould were coated using cobalt aluminate coatings.When the addition of cobalt aluminate in coating is between 45%-65%,and the melt is poured into preheated shell moulds with fine silica sand as backing sand,the blades satisfied the surface grain size requirement is over 90%.In addition,comparisons of the surface grain size and the mechanical properties were also conducted between home-made and foreign-made blades.展开更多
目的对孕产妇出院准备度进行范围综述,旨在为未来临床母婴护理研究及实践提供参考。方法采用澳大利亚乔安娜布里格斯研究所的范围综述指南为方法学框架,计算机检索PubMed、Web of Science、Scopus、中国知网、万方数据库、中文科技期刊...目的对孕产妇出院准备度进行范围综述,旨在为未来临床母婴护理研究及实践提供参考。方法采用澳大利亚乔安娜布里格斯研究所的范围综述指南为方法学框架,计算机检索PubMed、Web of Science、Scopus、中国知网、万方数据库、中文科技期刊数据库和中国生物医学文献数据库孕产妇出院准备度的相关研究。检索时限为建库至2022年10月20日。结果纳入24篇文献。孕产妇出院准备度的影响因素包括社会人口学因素、孕产因素、心理因素、子女因素、家庭社会因素、医护人员相关因素和其他因素。孕产妇出院准备度的干预措施包括组建出院准备小组、入院至产前措施、产后至出院当日措施和出院后措施。孕产妇出院准备度评估量表种类较多,尚未统一评估标准。结论孕产妇的出院准备度水平不一,需关注孕产妇出院准备度的影响因素。未来可进一步研究孕产妇出院准备度的干预措施和评估标准,为提高孕产妇出院准备度水平提供参考。展开更多
文摘The control of grain size in superalloys is critical in the manufacture of gas turbine blades.The aim of the present research is to provide the technology for producing complicated hollow turbine blades with fine surface grains and better comprehensive mechanical properties.By melt superheating treatment and coating the internal surfaces of shell mould using a cobalt aluminate-bearing coating material,the in-uence of cobalt aluminate as inoculant on the surface grain sizes of turbine blade was studied with addition of cobalt aluminate:0,35%,45%-65% and 100% respectively.At the same time,the effects of cooling circumstances of the blades on surface grain sizes were also experimented under the same addition of cobalt aluminate.The results showed that the melt superheating treatment plays a significant role in the grain size and carbide morphology;and fine surface grains were obtained when the internal surfaces of shell mould were coated using cobalt aluminate coatings.When the addition of cobalt aluminate in coating is between 45%-65%,and the melt is poured into preheated shell moulds with fine silica sand as backing sand,the blades satisfied the surface grain size requirement is over 90%.In addition,comparisons of the surface grain size and the mechanical properties were also conducted between home-made and foreign-made blades.
文摘目的对孕产妇出院准备度进行范围综述,旨在为未来临床母婴护理研究及实践提供参考。方法采用澳大利亚乔安娜布里格斯研究所的范围综述指南为方法学框架,计算机检索PubMed、Web of Science、Scopus、中国知网、万方数据库、中文科技期刊数据库和中国生物医学文献数据库孕产妇出院准备度的相关研究。检索时限为建库至2022年10月20日。结果纳入24篇文献。孕产妇出院准备度的影响因素包括社会人口学因素、孕产因素、心理因素、子女因素、家庭社会因素、医护人员相关因素和其他因素。孕产妇出院准备度的干预措施包括组建出院准备小组、入院至产前措施、产后至出院当日措施和出院后措施。孕产妇出院准备度评估量表种类较多,尚未统一评估标准。结论孕产妇的出院准备度水平不一,需关注孕产妇出院准备度的影响因素。未来可进一步研究孕产妇出院准备度的干预措施和评估标准,为提高孕产妇出院准备度水平提供参考。