China is at a crucial stage of overcoming the middle-income trap, with the factors that drive economic growth having undergone significant changes, and domestic consumption playing a more important role in economic gr...China is at a crucial stage of overcoming the middle-income trap, with the factors that drive economic growth having undergone significant changes, and domestic consumption playing a more important role in economic growth. It is necessary, at this point, to promote mass consumption by expanding the middle-income group. The present paper puts forward the concept of the ＂double middle-income traps.＂ This refers to the situation in which an economy＇s per capita output stagnates and the size of the middle- income group is unable to expand for an extended period of time. These two factors are closely related. Based on data from the Chinese Social Survey conducted by the Institute of Sociology at the Chinese Academy of Social Sciences, the present paper analyzes the scale and development of middle-income groups, and the relationship among middle- income groups, the middle-class and middle-class identity. The marginal consumption propensities of middle-income groups are also considered. The findings of the paper indicate that the expansion of the middle-income group plays an important role in promoting mass consumption, maintaining continuous and stable economic growth, and overcoming the double middle-income traps.展开更多
The current article presents conceptual,preliminary and detailed aero-thermal redesign of a typical high pressure turbine nozzle guide vane.Design targets are lower coolant consumption,reduced manufacturing costs an...The current article presents conceptual,preliminary and detailed aero-thermal redesign of a typical high pressure turbine nozzle guide vane.Design targets are lower coolant consumption,reduced manufacturing costs and improved durability.These goals are sought by 25%reduction in vane count number and lower number of airfoils per segment.Design challenges such as higher airfoil loading,associate aerodynamic losses and higher thermal loads are discussed.In order to maximize coolant flow reduction and avoid higher aerodynamic losses,airfoil Mach distribution is carefully controlled.There has been an effort to limit design changes so that the proven design features of the original vane are used as much as possible.Accordingly,the same cooling concept is used with minor modifications of the internal structures in order to achieve desired coolant flow and internal heat transfer distribution.Platforms of the new design are quite similar to the original one except for cooling holes and application of thermal barrier coating(TBC).Detailed aerodynamics/heat transfer simulations reveals that the reduced trailing edge(T.E.)blockage and skin friction dominated the negative effect of increased secondary losses.As a result the reduced design performs acceptable in terms of total pressure loss and improving stage efficiency for a wide range of varying pressure ratio.Moreover,more than 20%cooling mass flow can be saved;while maximum and average metal temperatures as well as cross sectional temperature gradients have not been changed much.展开更多
文摘China is at a crucial stage of overcoming the middle-income trap, with the factors that drive economic growth having undergone significant changes, and domestic consumption playing a more important role in economic growth. It is necessary, at this point, to promote mass consumption by expanding the middle-income group. The present paper puts forward the concept of the ＂double middle-income traps.＂ This refers to the situation in which an economy＇s per capita output stagnates and the size of the middle- income group is unable to expand for an extended period of time. These two factors are closely related. Based on data from the Chinese Social Survey conducted by the Institute of Sociology at the Chinese Academy of Social Sciences, the present paper analyzes the scale and development of middle-income groups, and the relationship among middle- income groups, the middle-class and middle-class identity. The marginal consumption propensities of middle-income groups are also considered. The findings of the paper indicate that the expansion of the middle-income group plays an important role in promoting mass consumption, maintaining continuous and stable economic growth, and overcoming the double middle-income traps.
文摘The current article presents conceptual,preliminary and detailed aero-thermal redesign of a typical high pressure turbine nozzle guide vane.Design targets are lower coolant consumption,reduced manufacturing costs and improved durability.These goals are sought by 25%reduction in vane count number and lower number of airfoils per segment.Design challenges such as higher airfoil loading,associate aerodynamic losses and higher thermal loads are discussed.In order to maximize coolant flow reduction and avoid higher aerodynamic losses,airfoil Mach distribution is carefully controlled.There has been an effort to limit design changes so that the proven design features of the original vane are used as much as possible.Accordingly,the same cooling concept is used with minor modifications of the internal structures in order to achieve desired coolant flow and internal heat transfer distribution.Platforms of the new design are quite similar to the original one except for cooling holes and application of thermal barrier coating(TBC).Detailed aerodynamics/heat transfer simulations reveals that the reduced trailing edge(T.E.)blockage and skin friction dominated the negative effect of increased secondary losses.As a result the reduced design performs acceptable in terms of total pressure loss and improving stage efficiency for a wide range of varying pressure ratio.Moreover,more than 20%cooling mass flow can be saved;while maximum and average metal temperatures as well as cross sectional temperature gradients have not been changed much.
