45,519 research outputs found
A Taxonomic and Ecological Study of the Asilidae of Michigan
Seventy-two species of Asilidae have been recorded from Michigan. An additional seven which may occur are included. Keys to subfamilies, genera and species are given. Two subfamilies and twenty-five genera are represented. A discussion of specific identification, habitat, and distribution is given where possible.
The Laphria canis complex, index complex, and aeatus complex are discussed. One new species, Laphria calvescenta is described. Laphria disparella has been raised from synonymy. Machimus virginicus was removed from Asilus sensu-latu and placed in the genus Machimus
Exciton-polaron complexes in pulsed electrically-detected magnetic resonance
Several microscopic pathways have been proposed to explain the large magnetic
effects observed in organic semiconductors, but identifying and characterising
which microscopic process actually influences the overall magnetic field
response is challenging. Pulsed electrically-detected magnetic resonance
provides an ideal platform for this task as it intrinsically monitors the
charge carriers of interest and provides dynamical information which is
inaccessible through conventional magnetoconductance measurements. Here we
develop a general time domain theory to describe the spin-dependent reaction of
exciton-charge complexes following the coherent manipulation of paramagnetic
centers through electron spin resonance. A general Hamiltonian is treated, and
it is shown that the transition frequencies and resonance positions of the
exciton-polaron complex can be used to estimate inter-species coupling. This
work also provides a general formalism for analysing multi-pulse experiments
which can be used to extract relaxation and transport rates
Design of an inert fluid injection system, phase 3 Final report
Research, development, and design of velocity trim system for third stage of Delta launch vehicl
Stability of shear flow with density gradient and viscosity
Stability of shear flow with density gradient and viscosit
Using coherent dynamics to quantify spin-coupling within triplet-exciton/polaron complexes in organic diodes
Quantifying the spin-spin interactions which influence electronic transitions
in organic semiconductors is crucial for understanding their
magneto-optoelectronic properties. By combining a theoretical model for three
spin interactions in the coherent regime with pulsed electrically detected
magnetic resonance experiments on MEH-PPV diodes, we quantify the spin-coupling
within complexes comprising three spin-half particles. We determine that these
particles form triplet-exciton:polaron pairs, where the polaron:exciton
exchange is over 5 orders of magnitude weaker (less than 170 MHz) than that
within the exciton. This approach providing a direct spectroscopic approach for
distinguishing between coupling regimens, such as strongly bound trions, which
have been proposed to occur in organic devices.Comment: 5 pages, 4 figure
Aircraft and satellite measurement of ocean wave directional spectra using scanning-beam microwave radars
A microwave radar technique for remotely measuring the vector wave number spectrum of the ocean surface is described. The technique, which employs short-pulse, noncoherent radars in a conical scan mode near vertical incidence, is shown to be suitable for both aircraft and satellite application, the technique was validated at 10 km aircraft altitude, where we have found excellent agreement between buoy and radar-inferred absolute wave height spectra
MULTIPAC, a multiple pool processor and computer for a spacecraft central data system, phase 2 Final report
MULTIPAC, multiple pool processor and computer for deep space probe central data syste
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