Now showing items 21-30 of 37
High resolution laser spectroscopy of relaxation and the excitation lineshape of excitons in GaAs quantum well structures
(Elsevier, 1990-04-01)
A new class of measurements on GaAs quantum well structures based on frequency domain nonlinear laser spectroscopy is described. Room temperature measurements of the excitation relaxation show an interference effect in the ...
Properties and device applications of deep quantum well resonant tunneling structures
(Elsevier, 1990-04-01)
A self-consistent quantum mechanical simulation is used to study the effects of doping, spacer layers, barrier height, barrier width and well doping on the bound state and bound state charge in a deep quantum well resonant ...
Synthesis and reactivity of rhodium(I) and iridium(I) complexes of the dianions of 2,3-pyrazinedicarboxylic and 2,5-pyrazinedicarboxylic acid
(Elsevier, 1990-03-27)
Rhodium and iridium complexes of the title ligands have been prepared containing cyclooctadiene, carbonyl, phosphine and phosphite ancillary ligands. The complexes are mononuclear or dinuclear depending on the method of ...
Epitaxial growth and characterization of GaAs/Al/GaAs heterostructures
(Elsevier, 1990-04-01)
We report on transmission electron microscopy, secondary ion mass spectroscopy, X-ray and Raman scattering studies of GaAs/Al/GaAs heterostructures grown by migration enhanced epitaxy.
Chemisorption and FTIR study of bimetallic Pt---Au/SiO₂catalysts
(Elsevier, 1990-02)
Pt/SiO₂, Au/SiO₂, and bimetallic Pt---Au/SiO₂ catalysts were prepared by incipient wetness impregnation of nonporous SiO₂. The catalysts were characterized after reduction in H₂ by static volumetric chemisorption and ...
The mechanism of the oxidation of propene to acrolein over antimony-tin mixed oxide catalysts
(Elsevier, 1990-05)
The oxidation of propenes such as 13CH2=CH---CH,3, CH2=CH-CD3, cis---CHD=CD---CH3, and CH2---CH---CH3 was studied over Sb6O13, SnO2, and Sb---Sn mixed oxide catalysts. The results with 13CH2=CH---CH3 and CH2=CH---CD3 were ...
Thermodynamics of the (lanthanum + strontium + copper + oxygen) high-Tc superconductors I. Heat capacities of SrCuO2, Sr2CuO3, and Sr14Cu24O41
(Elsevier, 1990-11)
The subambient heat capacities of three (SrO)x(CuO)y inter-oxide samples with x = Y = 1; x = 2, y = 1; and x = 1, y = 2, were measured as a part of an investigation into the chemical thermodynamics of the high-Tc superconducting ...
(1E,3E)-4-acetoxy-1-phenyldimethylsilyl-1,3-butadiene as a surrogate for (1E,3E)-1,4- diacetoxy-1,3-butadiene: a highly efficient synthesis of (+/-)-shikimic acid
(Elsevier, 1990)
The 5-step synthesis of (+/-)-shikimic acid has been achieved in 55% overall yield from (1E,3E)-4-acetoxy-1-phenyldimethylsilyl-1,3-butadiene, starting with its Diels-Alder reaction with 2-(trimethylsilyl)ethyl acrylate ...
Kinetic studies of the deactivation of O 2 ( 1 Σ g + ) and O( 1 D)
(John Wiley & Sons, Inc., 1990-12)
The kinetics of the deactivation of O 2 ( 1 Σ g + ) is studied in real time. O 2 ( 1 Σ g + ) is generated in this system by the O( 1 D) + O 2 reaction following O 3 laser flash photolysis in the presence of excess ...