The early stage evolution of local atomic structures in a multicomponent metallic glass during its crystallization process has been investigated via molecular dynamics simulation.It is found that the initial thermal s...The early stage evolution of local atomic structures in a multicomponent metallic glass during its crystallization process has been investigated via molecular dynamics simulation.It is found that the initial thermal stability and earliest stage evolution of the local atomic clusters show no strong correlation with their initial short-range orders,and this leads to an observation of a novel symmetry convergence phenomenon,which can be understood as an atomic structure manifestation of the ergodicity.Furthermore,in our system we have quantitatively proved that the crucial factor for the thermal stability against crystallization exhibited by the metallic glass is not the total amount of icosahedral clusters,but the degree of global connectivity among them.展开更多
The solid-liquid viscous system formed by high viscosity crystallization solution impacts the flow and separation performance.Therefore,it is very important to study the viscosity mechanism to improve viscosity and re...The solid-liquid viscous system formed by high viscosity crystallization solution impacts the flow and separation performance.Therefore,it is very important to study the viscosity mechanism to improve viscosity and regulate crystallization,ensuring a seamless production process.Herein,the viscosity of crystallization solution was taken as the measurement parameter of caffeine as a model drug.We investigated the viscosity mechanism of caffeine crystallization solutions by combining experiment and simulation.The results indicated that the weak interactions between caffeine and water result in increased viscosity of the caffeine crystallization solutions.Moreover,caffeine crystals possess elongated needle-like shapes,featuring a substantial specific surface area.Additionally,there isπ-πstacking occurring between the(200)crystal face and(110)crystal face,effectively fostering coalescence of the crystals towards the radial side of the crystal along its elongated axis,resulting in a more viscous crystallization system.The results contribute to comprehending the viscosity mechanism of crystal systems and provide theoretical foundation to enhance engineering efficiency in crystallization.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 52031016 and 11804027)the China Scholarship Council for financial support during part of this work
文摘The early stage evolution of local atomic structures in a multicomponent metallic glass during its crystallization process has been investigated via molecular dynamics simulation.It is found that the initial thermal stability and earliest stage evolution of the local atomic clusters show no strong correlation with their initial short-range orders,and this leads to an observation of a novel symmetry convergence phenomenon,which can be understood as an atomic structure manifestation of the ergodicity.Furthermore,in our system we have quantitatively proved that the crucial factor for the thermal stability against crystallization exhibited by the metallic glass is not the total amount of icosahedral clusters,but the degree of global connectivity among them.
基金supported by National Natural Science Foundation of China(grant No.21878067).
文摘The solid-liquid viscous system formed by high viscosity crystallization solution impacts the flow and separation performance.Therefore,it is very important to study the viscosity mechanism to improve viscosity and regulate crystallization,ensuring a seamless production process.Herein,the viscosity of crystallization solution was taken as the measurement parameter of caffeine as a model drug.We investigated the viscosity mechanism of caffeine crystallization solutions by combining experiment and simulation.The results indicated that the weak interactions between caffeine and water result in increased viscosity of the caffeine crystallization solutions.Moreover,caffeine crystals possess elongated needle-like shapes,featuring a substantial specific surface area.Additionally,there isπ-πstacking occurring between the(200)crystal face and(110)crystal face,effectively fostering coalescence of the crystals towards the radial side of the crystal along its elongated axis,resulting in a more viscous crystallization system.The results contribute to comprehending the viscosity mechanism of crystal systems and provide theoretical foundation to enhance engineering efficiency in crystallization.
