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
Many laboratories in the world have built telescope arrays based on silicon strip position-sensitive detectors such as MUST2^([1]),However,these methods lack detec-tion and identi cation capability of a large number o...Many laboratories in the world have built telescope arrays based on silicon strip position-sensitive detectors such as MUST2^([1]),However,these methods lack detec-tion and identi cation capability of a large number of low-energy particles produced over a wide range of beam en-ergies.To improve the present experimental capabilities,we have developed a trapezoid-shaped Frisch-grid ioniza-tion chamber(TFG-IC)as part of a telescope system to cover the identi cation of low-energy incident particles.展开更多
Heavy ion collision experiments are one of the important means to study the properties of nuclear matter.The CSR External-target Experiment(CEE)is a low-temperature,high-density nuclear matter measurement spectrom-ete...Heavy ion collision experiments are one of the important means to study the properties of nuclear matter.The CSR External-target Experiment(CEE)is a low-temperature,high-density nuclear matter measurement spectrom-eter used for heavy ion collision experiments,and it will become the rst large-scale nuclear physics experimental facility in China to operate in the GeV energy range after its completion.展开更多
An energy model for the melt of bulk metallic glass (BMG) with clusters was estab- lished, the Gibbs free energy and interfacial energy for the Zr-Al-Ni ternary alloy melt with Zr2Ni clusters were calculated, and the ...An energy model for the melt of bulk metallic glass (BMG) with clusters was estab- lished, the Gibbs free energy and interfacial energy for the Zr-Al-Ni ternary alloy melt with Zr2Ni clusters were calculated, and the effects of the clusters on the Gibbs free energy, interfacial energy and nucleation rate were analyzed. The results showed that the existence of the clusters in the Zr-Al-Ni ternary alloy melt enables the Gibbs free energy to decrease in the composition range where bulk metallic glass forms easily, makes the interfacial energy increase and changes the distribu- tion of the interfacial energy with the alloy composition. Because of the clusters in the melt, the Gibbs free energy of the Zr66Al8Ni26 alloy melt decreases about 0.3-1 kJ/mol and the interfacial energy between the melt and crystal nucleus increases about 0.016 J/m2. The nucleation rate of the undercooled Zr66Al8Ni26 alloy melt de- creases evidently under the influence of the clusters on Gibbs free energy and the interfacial energy, and the maximum of the nucleation rate in the melt with the Zr2Ni clusters is only about 107 mol1s1.展开更多
The influence of the low voltage pulsed magnetic field(LVPMF)on the microstructure transition of K4169 superalloy was investigated.The gradient microstructure of K4169 superalloy composed of columnar grains,coarse gra...The influence of the low voltage pulsed magnetic field(LVPMF)on the microstructure transition of K4169 superalloy was investigated.The gradient microstructure of K4169 superalloy composed of columnar grains,coarse grains,and fine grains was prepared through the combined method of LVPMF with directional solidification,which provided a new approach for the preparation of superalloy with gradient microstructure.The distribution of the Lorentz force and flow field under LVPMF effect was simulated,and therefore the microstructure transition mechanism was revealed.Results show that the microstructure transition should be attributed to the coupling effects of the Lorentz force and forced convection.展开更多
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.
文摘Many laboratories in the world have built telescope arrays based on silicon strip position-sensitive detectors such as MUST2^([1]),However,these methods lack detec-tion and identi cation capability of a large number of low-energy particles produced over a wide range of beam en-ergies.To improve the present experimental capabilities,we have developed a trapezoid-shaped Frisch-grid ioniza-tion chamber(TFG-IC)as part of a telescope system to cover the identi cation of low-energy incident particles.
文摘Heavy ion collision experiments are one of the important means to study the properties of nuclear matter.The CSR External-target Experiment(CEE)is a low-temperature,high-density nuclear matter measurement spectrom-eter used for heavy ion collision experiments,and it will become the rst large-scale nuclear physics experimental facility in China to operate in the GeV energy range after its completion.
基金the National Natural Science Foundation of China (Grant No. 50395100)
文摘An energy model for the melt of bulk metallic glass (BMG) with clusters was estab- lished, the Gibbs free energy and interfacial energy for the Zr-Al-Ni ternary alloy melt with Zr2Ni clusters were calculated, and the effects of the clusters on the Gibbs free energy, interfacial energy and nucleation rate were analyzed. The results showed that the existence of the clusters in the Zr-Al-Ni ternary alloy melt enables the Gibbs free energy to decrease in the composition range where bulk metallic glass forms easily, makes the interfacial energy increase and changes the distribu- tion of the interfacial energy with the alloy composition. Because of the clusters in the melt, the Gibbs free energy of the Zr66Al8Ni26 alloy melt decreases about 0.3-1 kJ/mol and the interfacial energy between the melt and crystal nucleus increases about 0.016 J/m2. The nucleation rate of the undercooled Zr66Al8Ni26 alloy melt de- creases evidently under the influence of the clusters on Gibbs free energy and the interfacial energy, and the maximum of the nucleation rate in the melt with the Zr2Ni clusters is only about 107 mol1s1.
基金National Key Research and Development Program of China(2018YFA0702900)National Science and Technology Major Project(J2019-VII-0002-0142)National Natural Science Foundation of China(51831007)。
文摘The influence of the low voltage pulsed magnetic field(LVPMF)on the microstructure transition of K4169 superalloy was investigated.The gradient microstructure of K4169 superalloy composed of columnar grains,coarse grains,and fine grains was prepared through the combined method of LVPMF with directional solidification,which provided a new approach for the preparation of superalloy with gradient microstructure.The distribution of the Lorentz force and flow field under LVPMF effect was simulated,and therefore the microstructure transition mechanism was revealed.Results show that the microstructure transition should be attributed to the coupling effects of the Lorentz force and forced convection.
