(color online) Thermal conductivity of resonant and kinked NWs. (a) Thermal conductance ratio for alkyl functionalized Si NWs with different branch lengths n (top panel) and for nanotrees with different branch lengths L_B (bottom panel). The insets show the phonon transmission function at low energies, and Fano-like resonant scattering is observed. (b) Phonon dispersion for pristine Si NWs, and two-side branched Si NWs with branch length 1.63 nm and 3.26 nm. (c) Relative thermal conductivity versus number of kinks in kinked Si NWs of 11.0 Å in diameter and 190.0 Å in length along the axial direction. (d) Thermal conductivity of boron carbide nanowires which are straight, with defect-free kinks, and with defective kinks, respectively. Panels adapted with permission from (a) Ref. [117], ©2009 APS; (b) Ref. [40], ©2016 APS; (c) Ref. [41], ©2013 ACS; (d) Ref. [118], ©2017 ACS.