A Preliminary List of the Lichens of Dickinson and Emmet Counties, lowa

A list of lichen species collected in Dickinson and Emmet Counties is presented

Notes on the Lichen Flora of Boone and Webster Counties, Iowa

Numerous collections of lichens have been made during the past several years from a variety of habitats in Boone and Webster counties. This progress report summarizes some of the authors\u27 general observations on the lichen flora of this area

A Guide to the Common Lichens of Boone and Story Counties, lowa

A key to the common lichens of Boone and Story Counties, Iowa is presented with brief descriptions of the genera and common species

Local Structure and Bonding of Carbon Nanothreads Probed by High-Resolution Transmission Electron Microscopy

Carbon nanothreads are a new one-dimensional sp^3-bonded nanomaterial of CH stoichiometry synthesized from benzene at high pressure and room temperature by slow solid-state polymerization. The resulting threads assume crystalline packing hundreds of micrometers across. We show high-resolution electron microscopy (HREM) images of hexagonal arrays of well-aligned thread columns that traverse the 80–100 nm thickness of the prepared sample. Diffuse scattering in electron diffraction reveals that nanothreads are packed with axial and/or azimuthal disregistry between them. Layer lines in diffraction from annealed nanothreads provide the first evidence of translational order along their length, indicating that this solid-state reaction proceeds with some regularity. HREM also reveals bends and defects in nanothread crystals that can contribute to the broadening of their diffraction spots, and electron energy-loss spectroscopy confirms them to be primarily sp^3-hybridized, with less than 27% sp^2 carbon, most likely associated with partially saturated “degree-4” threads