In situ observations of fullerene fusion and ejection in carbon nanotubes. by Gorantla, S, Börrnert, F, Bachmatiuk, A, Dimitrakopoulou, M, Schönfelder, R, Schäffel, F, Thomas, J, Gemming, T, Borowiak-Palen, E, Warner, J, Yakobson, B, Eckert, J, Büchner, B, Rümmeli, M