  The process of formation for an ice crystal with elaborate, symmetrical
patterns from the water vapor is usually complicated and the corresponding
mechanism is still not clear. Here, we experimentally constructed the 3D
tubular ice crystals within a thin chamber layer filled with air in a freezer
with high humidity at -27 degrees celsius. We here also propose to investigate
the dynamic formation of hollow structures from the perspective of Turing's
reaction-diffusion process, and a mathematical modelling of the 3D tubular
structures composed of ice crystals is conducted by regarding the cooled air
molecule (C-AM) as the activator and room-temperature air molecules(RT-AM) as
the inhibitor. The simulation generated a hollow tube array that has similar
geometric feature with the ice crystal structure of hollow columns in the
experiment. This model offers a possibility to explore the Turing instability
in the process of ice crystal formation.
