Two-dimensional nanopores are very promising for high-permeance molecular sieving. but the molecular backflow from permeate-side to feed-side is not beneficial for improving molecular permeance. We study the quasi-unidirectional molecular transport through a graphene-hexagonal boron nitride bilayer nanopore. aiming to realize a high-permeance molecular sieving. https://yeswellneses.shop/product-category/fish/