1. Laboratory of Mechanics of Novel Nanomaterials, Institute of Advanced Manufacturing Technologies, Peter the Great St. Petersburg Polytechnic University, Politecnicheskaya Str. 29, St. Petersburg 195251, Russia
2. Saint Petersburg State University, Universitetskya emb. 7/9, St. Petersburg 199034, Russia
3. Laboratory of Mechanics of Nanomaterials and Theory of Defects, Institute for Problems of Mechanical Engineering, Russian Academy of Sciences, Bolshoy pr. 61, St. Petersburg 199178, Russia
4. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China