The microstructural constituents and the crystallographic morphology of the primary intermetallic phases in permanent-mould-cast Mg-Zn-Al alloys with typical compositions within high zinc castable domain were investig...The microstructural constituents and the crystallographic morphology of the primary intermetallic phases in permanent-mould-cast Mg-Zn-Al alloys with typical compositions within high zinc castable domain were investigated. Three kinds of primary compounds with distinct morphology were identified as Mg32(Al,Zn)49(τ), MgZn(ε), and a ternary icosahedral quasi-crystalline compound (denoted with Q). The constituent is found to change with Zn and Al content and their concentration ratio. Alloys with middle mass ratio of Zn to Al and Al content, consist of α-Mg and τ phase, while alloys with high mass ratio of Zn to Al and low Al are composed of α-Mg, ε and a small amount of τ, those with low ratio of Zn to Al and high Al consist of α-Mg with Q. Solidification characteristics and process were proposed. The solidification ranges and liquidus temperature decrease with increasing Zn and Al content for τ-and Q-type alloys, whereas ε-type alloy shows reverse tendency. The second phase transformation moves to higher temperature range when Al content increases and ratio of Zn to Al decreases.展开更多
Atopic dermatitis(AD)is a common disease clinically characterized by chronic recurrent eczematous lesions,dry skin,and pruritus.AD can negatively impact patients’quality of life.The prevalence of AD in China has been...Atopic dermatitis(AD)is a common disease clinically characterized by chronic recurrent eczematous lesions,dry skin,and pruritus.AD can negatively impact patients’quality of life.The prevalence of AD in China has been increasing during the past few decades.Based on the most recent advances in the treatment of AD,we updated the 2014 version of the Guidelines for Diagnosis and Treatment of Atopic Dermatitis in China regarding the definition,epidemiology,pathogenesis,clinical classification,diagnosis,prevention,and treatment of AD.展开更多
基金Project(50301018) supported by the National Natural Science Foundation of China
文摘The microstructural constituents and the crystallographic morphology of the primary intermetallic phases in permanent-mould-cast Mg-Zn-Al alloys with typical compositions within high zinc castable domain were investigated. Three kinds of primary compounds with distinct morphology were identified as Mg32(Al,Zn)49(τ), MgZn(ε), and a ternary icosahedral quasi-crystalline compound (denoted with Q). The constituent is found to change with Zn and Al content and their concentration ratio. Alloys with middle mass ratio of Zn to Al and Al content, consist of α-Mg and τ phase, while alloys with high mass ratio of Zn to Al and low Al are composed of α-Mg, ε and a small amount of τ, those with low ratio of Zn to Al and high Al consist of α-Mg with Q. Solidification characteristics and process were proposed. The solidification ranges and liquidus temperature decrease with increasing Zn and Al content for τ-and Q-type alloys, whereas ε-type alloy shows reverse tendency. The second phase transformation moves to higher temperature range when Al content increases and ratio of Zn to Al decreases.
文摘Atopic dermatitis(AD)is a common disease clinically characterized by chronic recurrent eczematous lesions,dry skin,and pruritus.AD can negatively impact patients’quality of life.The prevalence of AD in China has been increasing during the past few decades.Based on the most recent advances in the treatment of AD,we updated the 2014 version of the Guidelines for Diagnosis and Treatment of Atopic Dermatitis in China regarding the definition,epidemiology,pathogenesis,clinical classification,diagnosis,prevention,and treatment of AD.
