2,450 research outputs found

    Biology of the Genus \u3ci\u3eHemileuca\u3c/i\u3e (Lepidoptera: Saturniidae) in Michigan

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    The habitats and host plants of buckmoths (Hemileuca: Saturniidae: Hernileucinae) in Michigan are described and compared to those of the three species known from eastern North America, H. maia, H. nevadensls, and H. lucina. Michigan populations show variation in host plant and habitat use spanning the entire range of all three species. The presence of transitional phenotypes and the host plant and habitat data suggest that Michigan populations are a single, variable species. These things combined with the intermediate geographical location of Michigan\u27s populations call into question the taxonomic distinctness of the three eastern buckmoth species

    Reticulate Evolution In The Appalachian Aspleniums

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137493/1/evo00117.pd

    Plant Speciation: The Classical Approach

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137527/1/evo05555.pd

    The Genus Diellia And The Value Of Characters In Determining Fern Affinities

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141528/1/ajb206446.pd

    (13) Proposal to designate reproductively competent species of hybrid origin by an × placed in brackets (reword Article H.3 Note 1)

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149747/1/tax01103.pd

    Superconducting tantalum disulfide nanotapes; growth, structure and stoichiometry

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    Superconducting tantalum disulfide nanowires have been synthesised by surface-assisted chemical vapour transport (SACVT) methods and their crystal structure, morphology and stoichiometry studied by powder X-ray diffraction (PXD), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and nanodiffraction. The evolution of morphology, stoichiometry and structure of materials grown by SACVT methods in the Ta-S system with reaction temperature was investigated systematically. High-aspect-ratio, superconducting disulfide nanowires are produced at intermediate reaction temperatures (650 degrees C). The superconducting wires are single crystalline, adopt the 2H polytypic structure (hexagonal space group P6(3)/mmc: a = 3.32(2) angstrom, c = 12.159(2) angstrom; c/a = 3.66) and grow in the <2<(1)over bar>(1) over bar0> direction. The nanowires are of rectangular cross-section forming nanotapes composed of bundles of much smaller fibres that grow cooperatively. At lower reaction temperatures nanowires close to a composition of TaS3 are produced whereas elevated temperatures yield platelets of 1T TaS2

    Precise Neutron Magnetic Form Factors

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    Precise data on the neutron magnetic form factor G_{mn} have been obtained with measurements of the ratio of cross sections of D(e,e'n) and D(e,e'p) up to momentum transfers of Q^2 = 0.9 (GeV/c)^2. Data with typical uncertainties of 1.5% are presented. These data allow for the first time to extract a precise value of the magnetic radius of the neutron.Comment: 10 pages, 2 figures, submitted to Physics Letters

    Measurement of the recoil polarization in the p (\vec e, e' \vec p) pi^0 reaction at the \Delta(1232) resonance

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    The recoil proton polarization has been measured in the p (\vec e,e'\vec p) pi^0 reaction in parallel kinematics around W = 1232 MeV, Q^2 = 0.121 (GeV/c)^2 and epsilon = 0.718 using the polarized c.w. electron beam of the Mainz Microtron. Due to the spin precession in a magnetic spectrometer, all three proton polarization components P_x/P_e = (-11.4 \pm 1.3 \pm 1.4) %, P_y = (-43.1 \pm 1.3 \pm 2.2) %, and P_z/P_e = (56.2 \pm 1.5 \pm 2.6) % could be measured simultaneously. The Coulomb quadrupole to magnetic dipole ratio CMR = (-6.4\pm 0.7_{stat}\pm 0.8_{syst}) % was determined from P_x in the framework of the Mainz Unitary Isobar Model. The consistency among the reduced polarizations and the extraction of the ratio of longitudinal to transverse response is discussed.Comment: 5 pages LaTeX, 1 table, 2 eps figure
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