Brownian dynamics was used to simulate the behavior of the different length polymer single-chains through the nanopores at different temperatures and flow rates.The presence of critical flow rate was confirmed.The results showed the translocation probability increased with the decrease of system temperature at the same flow.The loss of conformational entropy caused by the translocation was lower at lower temperatures

and then the critical flow Jc decreased.This might pullthe smaller chains flow through holes easier.The slopes of translocation probability of samples containing different chain lengths versus flow were almost coincided

which meant that the critical flow Jc was irrelevant with the length of polymer chains.The simulation results were all consistent with theoretical prediction.The translocation time of the polymer chain increased linearly with the length of polymer chain under the constant flow rate.Polymer chains were stretched along the x direction of the flow field when they crossed through the nanopores during the translocation process.The stretching stress reached the highest value when half of the single-polymer chain passed the nanopore.This was because the confinement of polymer chain reached the highest at this moment.And the polymer chain in the vertical direction of the flow field had no obvious effect.