Semirational solutions and baseband modulational instability of the AB system in fluid mechanics Lei Wang, Zi-Zhe Wang, Dong-Yang Jiang, Feng-Hua Qi and Rui Guo Eur. Phys. J. Plus, 130 10 (2015) 199 Published online: 12 October 2015 DOI: 10.1140/epjp/i2015-15199-8