Protein channels allow the selective passage of ions and molecules through the plasma membrane of cells.Due to the rapid and selective transport properties,these protein channels have a wide range of potential application,such as,DNA sequencing,protein translocation and polynucleotides.However,the weak mechanical properties and rigorous environmental demands of the protein channels show great limitation to their practical applications.To solve these limitations,biomimetic solid-state nanochannels by fabricating nanoscale confinement and altering surface chemical characteristic have been recently extensively studied.To understand and evaluate ion-transport behavior in the artificial nanochannels requires to understand the surface effects.Especially,when the size of nanochannel is reduced down to 1-2 nm in 2 dimensions,the electrostatic interactions,hydration force and van der Waals forces should have great influence on the ion-transport than 1-Dimensional nanochannels.In this work,we present a microscopic view of ion transport through barrier layer of porous anodic alumina membrane by using MD and experiment.First,the KCl and CaCl2 transport through the anodic alumina ion channel(AAIC)with different concentrations have been studied by using MD.The results show that ionic hydration plays an important role on ionic current rectification(ICR)in AAIC.The energy cost of removing the first-shell water molecules from ions significantly affects ions selectivity of AAIC.Part of transport potential compensates for the loss of ion stability as a result of desolvation.In addition,the desolvation of ions increases as bulk concentration decreases,which can be attributed to the electrostatic and steric interactions.Divalent cation(Ca2+)will induce the charge inversion in the negatively charged AAIC with concentration of 1 M.The charge inversion is mainly caused by interaction of water and ion.The phenomena will disappear at the concentration of CaCl2 reducing to 100 mM.