▎ 摘　　要

Pillared 3D carbon architectures, with the graphene layers and carbon nanotubes connected by topological junctions, have been produced and observed, as reported recently. However, the atomistic details of such junctions are hard to discern in microscopy and remain presently unclear. The simplest junction contains six heptagons in the transition region between the nanotube and graphene. Although these junctions make the pillared architectures possible, they are susceptible to failure when the whole structure undergoes mechanical or thermal Stress. In this work we consider "nanochimneys", a variety of special junctions with cones in between the nanotube and graphene parts. We explore the structures of the nanochimneys (NCs) and determine their underlying topological requirements. We also study the thermal conductance of these pillared architectures and show that NCs conduct heat better than regular simple junctions.