▎ 摘　　要

The electronic and transport properties of new hybrid 2D-1D-2D structures of carbon atoms, which are graphene sheets continuously connected through a fragment of a single-layer carbon nanotube, frequently observed experimentally, are theoretically studied. The evolution of the electronic properties of such systems with "zigzag" carbon nanotubes of various diameters with chirality indices (14, 0), (15, 0), (16, 0), and (18, 0) is studied using the tight coupling method within electron density functional theory. The calculation of the transmission coefficient demonstrates a strong nonlinearity in the behavior of the transport properties of these structures near the Fermi energy as a function of the diameter of carbon nanotubes, which explains discrepancies in the previously obtained experimental data.