Synthesis and microwave absorption properties of graphene-oxide(GO)/polyaniline nanocomposite with gold nanoparticles*Project supported by the National Basic Research Program of China (Grant Nos. 2011CB932700 and 2011CB932703), the National Natural Science Foundation of China (Grant Nos. 61335006, 61378073, and 61077044), and the Beijing Natural Science Fund (Grant No. 4132031). (August 2015)