The present work is focused on the relationship between effective segregation coefficient keff and tem- perature of melting zone for purification of phosphorus by zone melting method. Values of keff at four temperatur...The present work is focused on the relationship between effective segregation coefficient keff and tem- perature of melting zone for purification of phosphorus by zone melting method. Values of keff at four temperatures of melting zone are obtained for zone pass n = 1 at travel velocity of molten zone v = 5x 10^-3 m. h^-1 and initial impu- rity concentration C0〈10 μg.g-1, lnkeff is a linear function of 1/T. The keff values of A1, Ca, Cr, Fe, Cd and Sb in- crease with temperatures while that of Mg is almost constant. The purification is acceptable at lower temperature of melting zone such as 323 K. The variations of enthalpy and entropy between impurities and phosphorus in the liq- uid and solid ohases are also 19resented.展开更多
The effective segregation coefficient K-e of oxygen in terbium metal was deduced from a comparison of the theoretical curves with the concentration distributions found experimentally after a floating zone refining tre...The effective segregation coefficient K-e of oxygen in terbium metal was deduced from a comparison of the theoretical curves with the concentration distributions found experimentally after a floating zone refining treatment. Thp result shows that K-e is equal to 1.2 which is an important parameter for floating zone refining terbium.展开更多
The model of effective segregation coefficient(Keff) of solute atoms has been developed by considering the effect of environment work on barrier potential of atom motion at solid/liquid interface.It was found that not...The model of effective segregation coefficient(Keff) of solute atoms has been developed by considering the effect of environment work on barrier potential of atom motion at solid/liquid interface.It was found that not only the amount but also the type of environ ment work strongly affected the Keff in addition to the growth velocity R.展开更多
Molecular dynamics simulations are employed to investigate the effect of thermal convection induced only by dissipative lateral walls on density segregation of the strongly driven binary granular gases under low gravi...Molecular dynamics simulations are employed to investigate the effect of thermal convection induced only by dissipative lateral walls on density segregation of the strongly driven binary granular gases under low gravity conditions. It is found that the thermal convection due to dissipative lateral walls has significant influence on the segregation intensity of the system. The dominant factor in determining the degree of segregation achieved by the system is found to be the relative convection rate between differing species. Moreover, a qualitative explanation is proposed for the relationship between the thermal convection due to dissipative lateral walls and the observed segregation intensity profiles.展开更多
We discuss some dynamic properties of the segregation in vertically vibrated binary granular mixtures with the same size.We present a method that can accurately calculate the order parameter in the simulation.By use o...We discuss some dynamic properties of the segregation in vertically vibrated binary granular mixtures with the same size.We present a method that can accurately calculate the order parameter in the simulation.By use of the time evolution of the order parameter,we have found that the convergence of the segregated state depends at least on the vibration amplitude,the total mass of the particles,and also the density difference between the lighter and heavier particles.The convergence is quicker for larger vibration amplitude,lighter total mass of the particles and more density difference between the lighter and heavier particles.We have also found that thefluctuation is larger even after the steady state is reached for lighter total mass of the particles and less density difference between the lighter and heavier particles.展开更多
文摘The present work is focused on the relationship between effective segregation coefficient keff and tem- perature of melting zone for purification of phosphorus by zone melting method. Values of keff at four temperatures of melting zone are obtained for zone pass n = 1 at travel velocity of molten zone v = 5x 10^-3 m. h^-1 and initial impu- rity concentration C0〈10 μg.g-1, lnkeff is a linear function of 1/T. The keff values of A1, Ca, Cr, Fe, Cd and Sb in- crease with temperatures while that of Mg is almost constant. The purification is acceptable at lower temperature of melting zone such as 323 K. The variations of enthalpy and entropy between impurities and phosphorus in the liq- uid and solid ohases are also 19resented.
文摘The effective segregation coefficient K-e of oxygen in terbium metal was deduced from a comparison of the theoretical curves with the concentration distributions found experimentally after a floating zone refining treatment. Thp result shows that K-e is equal to 1.2 which is an important parameter for floating zone refining terbium.
文摘The model of effective segregation coefficient(Keff) of solute atoms has been developed by considering the effect of environment work on barrier potential of atom motion at solid/liquid interface.It was found that not only the amount but also the type of environ ment work strongly affected the Keff in addition to the growth velocity R.
基金Supported by the National Natural Science Foundation of China under Grant No 11404104the Natural Science Foundation of Hubei Province of China under Grant No 2014CFC1127
文摘Molecular dynamics simulations are employed to investigate the effect of thermal convection induced only by dissipative lateral walls on density segregation of the strongly driven binary granular gases under low gravity conditions. It is found that the thermal convection due to dissipative lateral walls has significant influence on the segregation intensity of the system. The dominant factor in determining the degree of segregation achieved by the system is found to be the relative convection rate between differing species. Moreover, a qualitative explanation is proposed for the relationship between the thermal convection due to dissipative lateral walls and the observed segregation intensity profiles.
基金the National Natural Science Foundation of China(Grant Nos.10875166 and 11274355)。
文摘We discuss some dynamic properties of the segregation in vertically vibrated binary granular mixtures with the same size.We present a method that can accurately calculate the order parameter in the simulation.By use of the time evolution of the order parameter,we have found that the convergence of the segregated state depends at least on the vibration amplitude,the total mass of the particles,and also the density difference between the lighter and heavier particles.The convergence is quicker for larger vibration amplitude,lighter total mass of the particles and more density difference between the lighter and heavier particles.We have also found that thefluctuation is larger even after the steady state is reached for lighter total mass of the particles and less density difference between the lighter and heavier particles.
