▎ 摘　　要

(Received 13 May 2022; revised 31 August 2022; accepted 3 November 2022; published 17 November 2022) It is shown using the method of molecular dynamics that the motion of carbon nanoparticles (rectangular graphene flakes, spherical fullerenes of size L < 10 nm) on the surface of a thermalized graphene sheet lying on a flat substrate can be described as the motion of particles in a viscous medium with a constant coefficient of friction, the value of which depends on the temperature and particle size. It has been shown that there are two types of effective friction: diffusion and ballistic. In the ballistic regime of motion (at velocities v > 200 m/s), deceleration occurs due to the interaction of moving nanoparticles with thermal out-of-plane bending vibrations of a graphene sheet. Because of this, with the increasing temperature, the coefficient of friction monotonically increases. In the diffusion regime of motion (at v < 20 m/s), friction arises due to the need for the particle to overcome local energy barriers, therefore it decreases with increasing temperature. The difference between ballistic and diffusion friction is most pronounced at low temperatures, since the mobility of nanoparticles in the ballistic regime of motion decreases with increasing temperature, while in the diffusion regime it monotonously increases. Thermophoresis modeling shows that at large values of the temperature gradient along the substrate, a ballistic mode of motion of nanoparticles is realized. In this mode, the mobility of nanoparticles does not depend on their shape and size, but is determined only by the value of the temperature gradient. It is shown that the presence of a normal force pressing the nanoparticle to the substrate leads to an increase in its friction with the substrate.