The longitudinal-random-fieM mixed Ising model consisting of arbitrary spin values has been studied by the use of an effective field theory with correlations （EFT）. The phase diagrams of systems with mixed spins： ...The longitudinal-random-fieM mixed Ising model consisting of arbitrary spin values has been studied by the use of an effective field theory with correlations （EFT）. The phase diagrams of systems with mixed spins： σ = 1/2, S = 1; σ = 1/2, S = 3/2 are plotted. Not only the discontinuity at T = 0 K, is found when both longitudinal fields are trimodal distributed, but also the trieritical behavior is observed in these phase diagrams between the bimodal and trimodal distributions of longitudinal fields, which is different from the single-spin one. The appearance of tricritical point is independent of the coordination number and spin values.展开更多
Recently, small hydroelectric generators have gained attention as a further development in water turbine technology for ultra low head drops in open channels. The authors have evaluated the application of cross-flow w...Recently, small hydroelectric generators have gained attention as a further development in water turbine technology for ultra low head drops in open channels. The authors have evaluated the application of cross-flow water turbines in open channels as an undershot type after removing the casings and guide vanes to substantially simplify these water turbines. However, because undershot cross-flow water turbines are designed on the basis of cross-flow water turbine runners used in typical pipelines, it remains unclear whether the number of blades has an effect on the performance or flow fields. Thus, in this research, experiments and numerical analyses are employed to study the performance and flow fields of undershot cross-flow water turbines with varying number of blades. The findings show that the turbine output and torque are lower, the fluctuation is significantly higher, and the turbine efficiency is higher for runners with 8 blades as opposed to those with 24 blades.展开更多
基金Supported by the Research Fund of Education Department under Grant No. 2009A305Science and Technology Department under Grant No. 20061023 in Liaoning Province of China+2 种基金National Natural Science Foundation of China under Grant No. 10874062National 211 Development Fund for Key Engineering Program of Liaoning UniversityYouth Foundation of Liaoning University under Grant No. 2007LDQN03
文摘The longitudinal-random-fieM mixed Ising model consisting of arbitrary spin values has been studied by the use of an effective field theory with correlations （EFT）. The phase diagrams of systems with mixed spins： σ = 1/2, S = 1; σ = 1/2, S = 3/2 are plotted. Not only the discontinuity at T = 0 K, is found when both longitudinal fields are trimodal distributed, but also the trieritical behavior is observed in these phase diagrams between the bimodal and trimodal distributions of longitudinal fields, which is different from the single-spin one. The appearance of tricritical point is independent of the coordination number and spin values.
文摘Recently, small hydroelectric generators have gained attention as a further development in water turbine technology for ultra low head drops in open channels. The authors have evaluated the application of cross-flow water turbines in open channels as an undershot type after removing the casings and guide vanes to substantially simplify these water turbines. However, because undershot cross-flow water turbines are designed on the basis of cross-flow water turbine runners used in typical pipelines, it remains unclear whether the number of blades has an effect on the performance or flow fields. Thus, in this research, experiments and numerical analyses are employed to study the performance and flow fields of undershot cross-flow water turbines with varying number of blades. The findings show that the turbine output and torque are lower, the fluctuation is significantly higher, and the turbine efficiency is higher for runners with 8 blades as opposed to those with 24 blades.
