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991.
Wang K.-C. Beccue S.M. Chang M.-C.F. Nubling R.B. Cappon A.M. Tsen T.C.-T. Chen D.M. Asbeck P.M. Kwok C.Y. 《Solid-State Circuits, IEEE Journal of》1992,27(10):1372-1378
A novel logic approach, diode-HBT logic (DHL), that is implemented with GaAlAs/GaAs HBTs and Schottky diodes to provide high-density and low-power digital circuit operation is described. This logic family was realized with the same technology used to produce emitter-coupled-logic/current-mode-logic (ECL/CML) circuits. The logic operation was demonstrated with a 19-stage ring oscillator and a frequency divider. A gate delay of 160 ps was measured with 1.1 mW of power per gate. The divider worked properly up to 6 GHz. Layouts of a DHL flip-flop and divider showed that circuit area and transistor count can be reduced by about a factor of 3, relative to ECL/CML circuits. The new logic approach allows monolithic integration of high-speed ECL/CML circuits with high-density DHL circuits with high-density DHL circuits 相似文献
992.
P. Oswald 《Liquid crystals》1991,10(5):709-714
We describe the dynamics of spreading of a smectic A liquid crystal deposited on a rotating disc. We show the existence of several regimes according to the film thickness. If it is thick enough, the thinning is controlled by bulk permeation; at intermediate thicknesses the surface dissipation dominates, whereas viscous effects begin to be felt only at very small thickness. 相似文献
993.
The kinetics and mechanism of the oxidation of 3,3′-dimethoxybenzidine (oda, o-dianisidine) by potassium bromate in aqueous acidic medium were studied by monitoring the formation rate of the reaction product, 3,3′-dimethoxy 4,4′-diphenoquinone at 447 nm. The reaction is, first order with respect to both the substrate and oxidant, and second order with respect to H+. The oda: bromate stoichiometric ratio is 1:1. Plausible mechanism and rate laws are proposed accounting the experimental findings. Computer simulations were done using the proposed mechanism. 相似文献
994.
Optoelectronic properties of asymmetrically strained II-VI CdZnTe single-quantum-well structures grown by molecular-beam epitaxy are reported. Indium doping CdZnTe n-type using a two-dimensional electron gas heterostructure achieved a carrier mobility of 5000 cm2·V-1 s-1 at 40 K. A shallow donor ionization energy of 14.5 meV was determined from Hall effect measurements. Fabrication of a large-area-mesa heterostructure device allowed us to investigate exciton absorption of the mixed type-I and type-II single quantum well. Control of the electron concentration in the quantum well allows optical absorption modulation using both the quantum-confined Stark effect (QCSE) and phase-space absorption quenching. Separation of electron and hole photocurrents in different layers is demonstrated and results in photogain. A heavy-hole red-shift of 9.9 meV/V due to the reverse QCSE is reported 相似文献
995.
Experimental results on adiabatic coupling into SOI photonic Crystal coupled-cavity waveguides 总被引:1,自引:0,他引:1
P. Sanchis J. Marti W. Bogaerts P. Dumon D. Van Thourhout R. Baets 《Photonics Technology Letters, IEEE》2005,17(6):1199-1201
The experimental implementation of an adiabatic coupling technique for efficient coupling between photonic crystal single-line defect waveguides and coupled-cavity waveguides is reported. The samples were fabricated in a silicon-on-insulator substrate using 248-nm-deep ultraviolet lithography. Experimental results are compared with three-dimensional (3-D) finite-difference time-domain simulations. Furthermore, the discrepancies between two-dimensional and 3-D simulation results are analyzed. 相似文献
996.
Time-dependent reorientations of resorcinol-based acridinidione (ADR) dyes in glycerol were studied using steady-state and
time-resolved fluorescence studies. The difference between fluorescence anisotropy decays recorded at 460 nm when exciting
at 250 nm and those obtained when exciting at 394 nm are reported. When exciting at 394 nm, the fluorescence anisotropy decay
is bi-exponential, while on exciting at 250 nm a mono-exponential fluorescence anisotropy decay is observed. We interpret
this in terms of different directions of the absorption dipole at 394 and 250 nm with the emission dipole respectively, which
is experimentally validated and further analysed as a prolate model of ellipsoid. 相似文献
997.
998.
Frateschi N.C. Osinski J.S. Beyler C.A. Dapkus P.D. 《Photonics Technology Letters, IEEE》1992,4(3):209-212
Low-threshold current (as low as 3.0 mA) and high-external efficiency (≈88%) InGaAs/GaAs lasers emitting at 1 μm under a stable fundamental transverse mode were obtained by using the temperature engineered growth technique for the growth on prepatterned substrates 相似文献
999.
P. Weibel D. Malterre M. Grioni B. Dardel Y. Baer 《Zeitschrift für Physik B Condensed Matter》1992,87(2):165-168
High resolution photoemission and bremsstrahlung isochromat spectroscopy experiments have been carried out on CeAg and LaAg. From a comparison between these two compounds, we extract the cerium 4f spectral function, we compare it with band structure calculations and with many-body model simulations based on the single-impurity Anderson Hamiltonian. We show that the localized 4f charge estimated from previous band structure calculations cannot be identified with the 4f occupation number deduced from the Anderson model. 相似文献
1000.
Algoet P.H. Marcus B.H. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1992,38(4):1276-1291
An irreducible Markov chain with stationary transition probabilities on a finite directed graph is considered. The probability of large deviations of the random variable denoting the empirical type of the first n transitions is investigated 相似文献