Snowflake growth provides a fascinating example of spontaneous pattern formation in nature.Attempts to understand this phenomenon have led to important insights in non-equilibrium dynamics observed in various active s...Snowflake growth provides a fascinating example of spontaneous pattern formation in nature.Attempts to understand this phenomenon have led to important insights in non-equilibrium dynamics observed in various active scientific fields,ranging from pattern formation in physical and chemical systems,to self-assembly problems in biology.Yet,very few models currently succeed in reproducing the diversity of snowflake forms in three dimensions,and the link between model parameters and thermodynamic quantities is not established.Here,we report a modified phase field model that describes the subtlety of the ice vapour phase transition,through anisotropic water molecules attachment and condensation,surface diffusion,and strong anisotropic surface tension,that guarantee the anisotropy,faceting and dendritic growth of snowflakes.We demonstrate that this model reproduces the growth dynamics of the most challenging morphologies of snowflakes from the Nakaya diagram.We find that the growth dynamics of snow crystals matches the selection theory,consistently with previous experimental observations.展开更多
A self-organisation is an universal phenomenon in nature and,in particular,is highly important in materials systems.Our goal was to develop a new theory that provides a computationally effective approach to this probl...A self-organisation is an universal phenomenon in nature and,in particular,is highly important in materials systems.Our goal was to develop a new theory that provides a computationally effective approach to this problem.In this paper a quasiparticle theory of a diffusional self-organisation of atoms in continuum space during the diffusional time scale has been introduced.This became possible due to two novelties,a concept of quasiparticles,fratons,used for a description of dynamic degrees of freedom and model Hamiltonian taking into account a directionality,length and strength of interatomic bonds.To illustrate a predictive power and achievable level of complexity of self-assembled structures,the challenging cases of self-assembling of the diamond,zinc-blende,helix and double-helix structures,from a random atomic distribution,have been successfully modelled.This approach opens a way to model a self-assembling of complex atomic and molecular structures in the atomic scale during diffusional time.展开更多
基金financial support through the CISTIC project of programme Investissements d’Avenir LabEx EMC3(ANR-10-LABX-09-01).
文摘Snowflake growth provides a fascinating example of spontaneous pattern formation in nature.Attempts to understand this phenomenon have led to important insights in non-equilibrium dynamics observed in various active scientific fields,ranging from pattern formation in physical and chemical systems,to self-assembly problems in biology.Yet,very few models currently succeed in reproducing the diversity of snowflake forms in three dimensions,and the link between model parameters and thermodynamic quantities is not established.Here,we report a modified phase field model that describes the subtlety of the ice vapour phase transition,through anisotropic water molecules attachment and condensation,surface diffusion,and strong anisotropic surface tension,that guarantee the anisotropy,faceting and dendritic growth of snowflakes.We demonstrate that this model reproduces the growth dynamics of the most challenging morphologies of snowflakes from the Nakaya diagram.We find that the growth dynamics of snow crystals matches the selection theory,consistently with previous experimental observations.
基金supported in part by the grant from the French National Agency for the Research(ANR)project‘Spiderman’.
文摘A self-organisation is an universal phenomenon in nature and,in particular,is highly important in materials systems.Our goal was to develop a new theory that provides a computationally effective approach to this problem.In this paper a quasiparticle theory of a diffusional self-organisation of atoms in continuum space during the diffusional time scale has been introduced.This became possible due to two novelties,a concept of quasiparticles,fratons,used for a description of dynamic degrees of freedom and model Hamiltonian taking into account a directionality,length and strength of interatomic bonds.To illustrate a predictive power and achievable level of complexity of self-assembled structures,the challenging cases of self-assembling of the diamond,zinc-blende,helix and double-helix structures,from a random atomic distribution,have been successfully modelled.This approach opens a way to model a self-assembling of complex atomic and molecular structures in the atomic scale during diffusional time.
