Phase Reentrances and Solid Deformations in Confined Colloidal Crystals.

A simple geometric constraint often leads to novel, complex crystalline phases distinct from the bulk. Using thin-film charge colloidal crystals, a model system with tunable interactions, we study the effects of geometric constraints. Through a combination of experiments and simulations, we systematically explore phase reentrances and solid deformation modes concerning geometrical confinement strength, identifying two distinct categories of phase reentrances below a characteristic layer number, N_{c}: one for bcc bulk-stable and another for fcc bulk-stable systems.

Multiple Scenarios of Low-Temperature Nucleation in Simple Liquids.

Usually, sufficient supercooling of a liquid is employed to bypass the free energy barrier and speed up crystallization. However, lowering the temperature T induces new issues competing with the crystallization, e.g.

Association between sociodemographic status and cardiovascular risk factors burden in community populations: implication for reducing cardiovascular disease burden.

Background: We aimed to evaluate the burden of cardiovascular (CV) risk factors in the community populations of Guangdong Province and its association with sociodemographic status (SDS).

Method: The data were from the community populations of Guangdong Province who have participated in the China PEACE Million Persons Project between 2016 and 2020 (n = 102,358, women 60.5% and mean age 54.

Revealing thermally-activated nucleation pathways of diffusionless solid-to-solid transition.

Solid-to-solid transitions usually occur via athermal nucleation pathways on pre-existing defects due to immense strain energy. However, the extent to which athermal nucleation persists under low strain energy comparable to the interface energy, and whether thermally-activated nucleation is still possible are mostly unknown. To address these questions, the microscopic observation of the transformation dynamics is a prerequisite.

Fast crystal growth at ultra-low temperatures.

It is believed that the slow liquid diffusion and geometric frustration brought by a rapid, deep quench inhibit fast crystallization and promote vitrification. Here we report fast crystal growth in charged colloidal systems under deep supercooling, where liquid diffusion is extremely low. By combining experiments and simulations, we show that this process occurs via wall-induced barrierless ordering consisting of two coupled steps: the step-like advancement of the rough interface that disintegrates frustration, followed by defect repairing inside the newly formed solid phase.

Revealing roles of competing local structural orderings in crystallization of polymorphic systems.

Most systems have more than two stable crystalline states in the phase diagram, which is known as polymorphism. Crystallization in such a system is often under strong influence of competing orderings linked to those crystals. However, how such competition affects crystal nucleation and ordering toward the final crystalline state is largely unknown.