  The structure of the unbound nuclei 9He, 10Li and 13Be has been explored
using breakup and proton-knockout from intermediate energy 11Be and 14,15B
beams. In the case of both N=7 isotones, virtual s-wave strength is observed
near threshold together with a higher-lying resonance. A very narrow structure
at threshold in the 12Be+n relative energy spectrum is demonstrated to arise
from the decay of the 14Be*(2+), discounting earlier reports of a strong
virtual s-wave state in 13Be.
