Numerical simulation on thermal accumulation of cemented tailings backfill

Based on the collaborative exploitation of deep mineral resources and geothermal resources, the thermal accumulation process of cemented tailings backfill(CTB) was studied by numerical simulation. The effects of thermal accumulation time, slurry proportions and temperature conditions on the thermal accumulation of backfill are analyzed, the influence of the heat conduction between backfill and surrounding rock, the heat convection between backfill and airflow on thermal accumulation were compared simultaneously. The results show that the total thermal accumulation capacity increases by approximately 85% within 10-90 d. The influence of surrounding rock temperature and initial temperature on total thermal accumulation capacity is more significant and it is approximately 2 times of the influence of slurry proportions under the conditions of this study. It is clear that the rise of surrounding rock temperature and the decrease of initial temperature can improve the thermal accumulation capacity more effectively. Moreover, the heat conduction accounts for a considerable proportion in the process of thermal accumulation, the average heat conduction capacity is approximately 25 times of the heat convection capacity. This study can provide the theoretical basis and application reference for the optimization of thermal accumulation process of CTB in the exploitation of geothermal resources.

Femtosecond Laser Thermal Accumulation-Triggered Micro-/Nanostructures with Patternable and Controllable Wettability Towards Liquid Manipulating

Versatile liquid manipulating surfaces combining patternable and controllable wettability have recently motivated considerable attention owing to their significant advantages in droplet-solid impacting behaviors,microdroplet self-removal,and liquid–liquid interface reaction applications.However,developing a facile and efficient method to fabricate these versatile surfaces remains an enormous challenge.In this paper,a strategy for the fabrication of liquid manipulating surfaces with patternable and controllable wettability on Polyimide(PI)film based on femtosecond laser thermal accumulation engineering is proposed.Because of its controllable micro-/nanostructures and chemical composition through adjusting the local thermal accumulation,the wettability of PI film can be tuned from superhydrophilicity(~3.6°)to superhydrophobicity(~151.6°).Furthermore,three diverse surfaces with patternable and heterogeneous wettability were constructed and various applications were successfully realized,including water transport,droplet arrays,and liquid wells.This work may provide a facile strategy for achieving patternable and controllable wettability efficiently and developing multifunctional liquid steering surfaces.