1. CCDC-Army Research Laboratory, FCDD-RLW-WA, Aberdeen Proving Ground, Maryland 21005-5066, USA
2. Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
3. Materials Science and Engineering Department, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA
4. Lawrence Livermore National Laboratory, 7000 East Ave., L-282, Livermore, California 94550, USA