College of Mathematics and Computational Science, Hunan First Normal University, Changsha 410205, China;
School of Mathematics and Statistics, Central South University, Changsha 410083, China;
LMBA, UMR CNRS 6205, Université de Bretagne-Sud, F-56000 Vannes, France;
School of Mathematics and Statistics, Changsha University of Science and Technology, Changsha 410004, China;
branching; random; walk; random; environment; quenched; moments; weighted; moments;