tation mechanism via inner-shell vacancies for the Pb + Pb and Pb + U systems. These calculations and the extrapolation for the U+ U system, which does not include effects from the spreading of the lsa state in the negative-energy continuum, reproduce the absolute positron yield as well as its dependence on Z and on the distances of closest approach within the limits of error.We would like to acknowledge the achievements of the UNILAC crew in making excellent U beams, P. Maier-Komor and E. Kellner for fabricating the delicate U targets, M. Richter, R. Hadsell, and F. Weik for their computational assistance, and H. Stettmeier and L. Richter for helping us during the initial phase of the work. We thank A large-amplitude ion-acoustic cylindrical soliton launched in an axisymetric cylindrical system collapses at the center of the cylinder. The highly nonlinear nature of the interaction is observed after the collapse, showing that many isolated pulses are emitted abruptly and propagate out without clear evolution of their wave forms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.