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N. Barnes P. Healey P. McKee A. W. O'Neill M. A. Z. Rejman-Greene E. G. Scott R. P. Webb B. R. White D. Wood 《Optical and Quantum Electronics》1992,24(4):S505-S516
An experimental 16-channel parallel interconnection system able to support 100 Mbits–1 per channel and an opto-electronic neural network operating at up to 50 Mbits–1 have been constructed to demonstrate the potential of optics in processing systems. Both experiments operate at a wavelength of 1.5m. Components developed for these systems include arrays of InGaAs/InP MQW surface modulators for low-power electrical-to-optical conversion; InGaAs/InP for detector arrays, which are hybrid integrated with GaAs amplifier arrays; and computer-generated holograms for efficient beam splitting and to encode weights in the optical beam intensities. Each of these demonstrations has considerable scope for increasing the degree of parallelism and the operating speed. Recent modifications to the neural network enable the weights to be varied and training has been demonstrated with a novel algorithm that uses the high operating speed to advantage. 相似文献
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Alam MS Kim IJ Nemati B O'Neill JJ Romero V Severini H Sun CR Wang P Zoeller MM Crawford G Fulton R Gan KK Kagan H Kass R Lee J Malchow R Morrow F Sung M White C Whitmore J Wilson P Butler F Fu X Kalbfleisch G Lambrecht M Skubic P Snow J Bortoletto D Brown DN Dominick J McIlwain RL Miao T Miller DH Modesitt M Schaffner SF Shibata EI Shipsey IP Battle M Ernst J Kroha H Roberts S Sparks K Thorndike EH Wang C Artuso M Goldberg M Haupt T Horwitz N Kennett R Moneti GC Playfer S Rozen Y Rubin P 《Physical review D: Particles and fields》1992,46(11):4822-4827
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A. E. Stuchbery A. G. White G. D. Dracoulis K. J. Schiffer B. Fabricius 《Zeitschrift für Physik A Hadrons and Nuclei》1991,338(2):135-138
Transient-field precessions were measured simultaneously for levels in the ground-state bands of156, 158, 160Gd as ions of these nuclei traversed a thin polarized Fe foil. Relative g-factors of levels up to 6 1 + were deduced, those of the 4 1 + levels being determined with greatest precision. In contrast with the conclusions of the recent report by Alzner et al. [1], our results are consistent with g(4 1 + ) having the same value in all three isotopes and imply g(2 1 + )=g(4 1 + ) in156Gd, consistent with nuclear structure models. 相似文献
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Spatial!y localized electrochemical activity at Al/Al2O3 electrodes has been investigated using scanning electrochemical microscopy (SECM) in order to establish the relationship between localized corrosion of Al (and Al alloys) with the defect structure of the native Al2O3 film. Local electron transfer at microscopic defects (2 to 50 microm radius) was visualized in acetonitrile solutions using the nitrobenzene/nitrobenzene radical anion (Eo approximately -1.6 V vs. Ag/Ag+) and tetracyanoquinodimethane/tetracyanoquinodimethane radical anion couples (Eo approximately -0.3 V) as redox mediators for imaging. SECM investigations revealed no significant differences in electrochemical activity at Al/AI203 electrodes in the two mediator solutions, indicating that electrical conduction at the defect sites is weakly dependent on interfacial potential and the electric field across the Al2O3 film. The density of electroactive defects observed by SECM varied by 2 to 3 orders of magnitude between electrodes prepared from the same source of Al (either 99.450% and 99.9995%) suggesting that electrical conduction in the native oxide is very sensitive to surface preparation. Defect densities as low as approximately 3 sites cm(-2) were readily measured by SECM. 相似文献