Effects of the content of Dy on structure and magnetic properties of DyxFe60.5-xPt39.5 alloys（x = 0, 0.5, 1.0, 1.5） were investigated. The results of XRD analysis proved that the phase-transitional temperature of Dy...Effects of the content of Dy on structure and magnetic properties of DyxFe60.5-xPt39.5 alloys（x = 0, 0.5, 1.0, 1.5） were investigated. The results of XRD analysis proved that the phase-transitional temperature of DyxFe60.5-xPt39.5 alloys from disordered face-centered-cubic structure to ordered face-centered-tetragonal cubic structure decreases with the increase of the content of Dy（x）. Suitable content of Dy can improve the exchange coupling between soft magnetic phase and hard magnetic phase by refining grain size, while the remanence ratio and coercivity of the Fe60.5Pt39.5 alloy can be significantly improved by a small replacement of Fe by Dy, good magnetic properties were obtained in Dy0.5Fe60.0Pt39.5 alloys.展开更多
The nanocrystalline structure of annealed Fe73.5 Cu1 W3Si13.5B9 alloy has been investigated by using the XRD and the TEM methods. The relation between the initial permeability and the microstructure of the annealed al...The nanocrystalline structure of annealed Fe73.5 Cu1 W3Si13.5B9 alloy has been investigated by using the XRD and the TEM methods. The relation between the initial permeability and the microstructure of the annealed alloy has been discussed. The crystalline phase in annealed Fe73.5 Cu1 W3Si13.5B9 alloy is the α-Fe(Si) phase with DO3 superstructure. The volume fraction, Si content and degree of order of the αFe(Si) phase increase with increasing annealing temperature. In the temperature range of 490-570℃, the α-Fe(Si) phase has a size of 13 nm, and its grain number increases as the annealing temperature is increased. The DO3 ordered region in the α-Fe(Si) grain is spherical approximately, and its size increases as the annealing temperature increases. The size of the DO3 ordered region is 12.8 nm at the temperature of 570℃,which is close to that of the α-Fe(Si) grain. There is obvious change in the structure of the residual amorphous phase during annealing, and the nearest atomic distance and the short-range order of residual amorphous phase reach maximum and minimum at 530℃, respectively. The initial permeability of annealed Fe73.5 Cu1 W3Si13.5 B9 alloy is not only dependent on the size, volume fraction and Si content of the α-Fe(Si) phase but also related to the structure state of the residual amorphous phase.展开更多
The optimization model based on Markov chain is established to optimize the prediction of industrial structure and provide reference for policy adjustment.The vectorization operator is used to transform the Markov pre...The optimization model based on Markov chain is established to optimize the prediction of industrial structure and provide reference for policy adjustment.The vectorization operator is used to transform the Markov prediction model into an optimization problem with constraints,which highlights the theoretical proof and computational rigor.Based on the data of three industrial structures in Yunnan Province from 1989 to 2019,this paper establishes Markov optimization model to predict the proportion of three industrial structures in Yunnan Province from 2020 to 2030.The maximum percentage average absolute error and hill inequality coefficient of the prediction are 1.2335%and 0.2,respectively.The order-degree of the three industrial structures is a stable series,which is stable around 1 after 1996.The sample data and the predicted values show four stages of change characteristics.After 2020,the three industrial structures are stable in the"three,two and one"structure.展开更多
基金Funded by the National Natural Science Foundation of China(No.50261002&50661002)
文摘Effects of the content of Dy on structure and magnetic properties of DyxFe60.5-xPt39.5 alloys（x = 0, 0.5, 1.0, 1.5） were investigated. The results of XRD analysis proved that the phase-transitional temperature of DyxFe60.5-xPt39.5 alloys from disordered face-centered-cubic structure to ordered face-centered-tetragonal cubic structure decreases with the increase of the content of Dy（x）. Suitable content of Dy can improve the exchange coupling between soft magnetic phase and hard magnetic phase by refining grain size, while the remanence ratio and coercivity of the Fe60.5Pt39.5 alloy can be significantly improved by a small replacement of Fe by Dy, good magnetic properties were obtained in Dy0.5Fe60.0Pt39.5 alloys.
文摘The nanocrystalline structure of annealed Fe73.5 Cu1 W3Si13.5B9 alloy has been investigated by using the XRD and the TEM methods. The relation between the initial permeability and the microstructure of the annealed alloy has been discussed. The crystalline phase in annealed Fe73.5 Cu1 W3Si13.5B9 alloy is the α-Fe(Si) phase with DO3 superstructure. The volume fraction, Si content and degree of order of the αFe(Si) phase increase with increasing annealing temperature. In the temperature range of 490-570℃, the α-Fe(Si) phase has a size of 13 nm, and its grain number increases as the annealing temperature is increased. The DO3 ordered region in the α-Fe(Si) grain is spherical approximately, and its size increases as the annealing temperature increases. The size of the DO3 ordered region is 12.8 nm at the temperature of 570℃,which is close to that of the α-Fe(Si) grain. There is obvious change in the structure of the residual amorphous phase during annealing, and the nearest atomic distance and the short-range order of residual amorphous phase reach maximum and minimum at 530℃, respectively. The initial permeability of annealed Fe73.5 Cu1 W3Si13.5 B9 alloy is not only dependent on the size, volume fraction and Si content of the α-Fe(Si) phase but also related to the structure state of the residual amorphous phase.
基金This research was funded by“Analysis of the Influence Mechanism of Modern Service Industry in Yunnan Province Based on Bayes Method”on the Project of Yunnan University Joint Fund(2017FH001-068).
文摘The optimization model based on Markov chain is established to optimize the prediction of industrial structure and provide reference for policy adjustment.The vectorization operator is used to transform the Markov prediction model into an optimization problem with constraints,which highlights the theoretical proof and computational rigor.Based on the data of three industrial structures in Yunnan Province from 1989 to 2019,this paper establishes Markov optimization model to predict the proportion of three industrial structures in Yunnan Province from 2020 to 2030.The maximum percentage average absolute error and hill inequality coefficient of the prediction are 1.2335%and 0.2,respectively.The order-degree of the three industrial structures is a stable series,which is stable around 1 after 1996.The sample data and the predicted values show four stages of change characteristics.After 2020,the three industrial structures are stable in the"three,two and one"structure.
