Now showing items 21-30 of 43
2D heteronuclear NMR measurements of spin-lattice relaxation times in the rotating frame of X nuclei in heteronuclear HX spin systems
(Elsevier, 1991-08)
Theoretical and experimental aspects of T1p are discussed for a heteronuclear HX two-spin system (T1pX) where only the X nucleus is spin-locked. An expression for T1pX in terms of spectral density functions and the effective ...
Analytic MODFET models beyond the triangular well approximation
(Elsevier, 1990-07)
A new approach to modeling normal interface modulation doped field-effect transistors (MODFETs) is presented in which the 2-D electron gas density is integrated along the channel instead of the channel potential. With this ...
Modulation of twin-emitter semiconductor lasers beyond the frequency of relaxation oscillations
(Elsevier, 1991-04-15)
Self-modulation above the relaxation oscillation frequency has been previously observed in a phased-array semiconductor lasers. Rate equations for a twin-emitter phased-array semiconductor laser are used to show that active ...
An alexandrite pumped Nd:glass regenerative amplifier for chirped pulse amplification
(Elsevier, 1992-08-15)
An alexandrite pumped, Nd:glass regenerative amplifier is demonstrated. This amplifier has been used with chirped pulse amplification to produce millijoule, picosecond pulses. Using this technique the overall gain bandwidth ...
Bias circuit instabilities and their effect on the d.c. current-voltage characteristics of double-barrier resonant tunneling diodes
(Elsevier, 1991-02)
Bias circuit stability has important implications for the study and application of double-barrier resonant tunneling structures. Stability criteria for resonant tunneling diodes are investigated for the common bias circuit ...
Numerical modeling of abrupt heterojunctions using a thermionic-field emission boundary condition
(Elsevier, 1993-03)
We present a numerical model in which the thermionic and tunneling mechanisms across an abrupt heterojunction interface are taken into account on the basis of the one dimensional drift-diffusion formulation. We use an ...
Retrospective correction of surface coil MR images using an automatic segmentation and modeling approach
(John Wiley & Sons, Ltd., 1997-05)
The use of surface coils in magnetic resonance imaging offers significant improvements in the signal-to-noise ratio over volume coils for many applications. However, the inhomogeneous reception profile of surface coils ...