分子机器中链状分子热传导性质的 理论研究分子机器中链状分子热传导性质的 理论研究.pdf

Modern Physics 现代物理, 2017, 7(6), 227-234 Published Online November 2017 in Hans. /journal/mp /10.12677/mp.2017.76026 Theoretical Study on the Heat Conductivities of Chain Molecules in Molecular Machines Jianping Huang1*, Jing Tang2 1 College of Information Science and Technology, Hunan Normal University, Changsha Hunan 2 College of Physics and Information Science, Hunan Normal University, Changsha Hunan th th th Received: Oct. 20 , 2017; accepted: Nov. 4 , 2017; published: Nov. 10 , 2017 Abstract The formula for energy flux of chain molecule vibrations in molecular machines was derived based on the lattice dynamics, and then the formula for heat conductivities of chain molecules was derived based on energy flux formula and Green-Kubo formula. In view of the fact that the line- widths of all phonons should be needed during the calculations of the heat conductivities of chain molecules, the formula for phonons’ linewidths was derived based on lattice dynamics and Green’s function theory. Finally the numerical calculations were carried out, and the results show that the heat conductivities of chain molecules increase and tend to infinity when their lengths increase and tend to infinity, and there is a big difference between the heat conductivities of a chain mole- cule and a cyclic molecule with the same length. The numerical results also show that the main contributions to the heat conductivities of long chain molecules were made by phonons with short wave vectors. Keywords Chain Molecule, Heat Conductivity, Energy Flux, Linewidth of Phonon, Lattice Dynamics 分子机器中链状分子热传导性质的 理论研究 1* 2 黄建平 ，唐 婧