263,579 research outputs found
Mix-and-match compatibility in asymmetric system markets
This paper shows that the private incentive for mix-and-match compatibility in system markets diverges from the social planner's incentive if competing suppliers are asymmetric in production cost or product quality. There can be too much or too little compatibility when the market is served by fully integrated system suppliers. Also, the market outcome involves socially too much incompatibility in the form of exclusive technological alliances when the market is composed of independent component suppliers. These results contrast with the standard one obtained in the symmetric setup and shed new light on public policy towards compatibility, technological alliances, and bundling practices in system markets
Pulse-shape discrimination between electron and nuclear recoils in a NaI(Tl) crystal
We report on the response of a high light-output NaI(Tl) crystal to nuclear
recoils induced by neutrons from an Am-Be source and compare the results with
the response to electron recoils produced by Compton scattered 662 keV
-rays from a Cs source. The measured pulse-shape discrimination
(PSD) power of the NaI(Tl) crystal is found to be significantly improved
because of the high light output of the NaI(Tl) detector. We quantify the PSD
power with a quality factor and estimate the sensitivity to the interaction
rate for weakly interacting massive particles (WIMPs) with nucleons, and the
result is compared with the annual modulation amplitude observed by the
DAMA/LIBRA experiment. The sensitivity to spin-independent WIMP-nucleon
interactions based on 100 kgyear of data from NaI detectors is estimated
with simulated experiments, using the standard halo model.Comment: 11page
Electronic structures of ZnCoO using photoemission and x-ray absorption spectroscopy
Electronic structures of ZnCoO have been investigated using
photoemission spectroscopy (PES) and x-ray absorption spectroscopy (XAS). The
Co 3d states are found to lie near the top of the O valence band, with a
peak around eV binding energy. The Co XAS spectrum provides
evidence that the Co ions in ZnCoO are in the divalent Co
() states under the tetrahedral symmetry. Our finding indicates that the
properly substituted Co ions for Zn sites will not produce the diluted
ferromagnetic semiconductor property.Comment: 3 pages, 2 figure
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