A method to calculate thermal conductivity of a nonperiodic system, bamboo Si1−xGex nanowire with axially degraded componentsMinggang Xia, Jinyun Han, Zhaofang Cheng, Shengli Zhang and Baowen LiEur. Phys. J. B, 90 10 (2017) 199DOI: https://doi.org/10.1140/epjb/e2017-80211-8