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Fermi-Energy Edge Singularity And Excitonic Enhancement Associated With The Second Subband In Asymmetric Modulation-Doped Quantum Wells , T. A. Fisher, Philip E. Simmonds, M. S. Skolnick, A. D. Martin, R. S. Smith
Fermi-Energy Edge Singularity And Excitonic Enhancement Associated With The Second Subband In Asymmetric Modulation-Doped Quantum Wells , T. A. Fisher, Philip E. Simmonds, M. S. Skolnick, A. D. Martin, R. S. Smith
Faculty of Engineering - Papers (Archive)
A study of the Fermi-energy edge singularity (FEES) in the second (n=2) subband of asymmetric modulation-doped (AlGa)As-(InGa)As-GaAs quantum wells (AMDQW’s) is reported. In one of the AMDQW’s a Schottky gate is employed to vary the electron density in the n=2 subband (ns,2) from 0 to 1×1011 cm-2. Temperature-dependent photoluminescence excitation (PLE) measurements clearly show that the n=2 PLE feature has FEES character for ns,2≳0.4×1011 cm-2. In contrast to PLE, photoluminescence (PL) intensity is not a true measure of oscillator strength, since PL intensity can be affected by competing recombination pathways. Temperature-dependent PL measurements have been performed on two types of …
Hartree-Fock Method Posed As A Density-Functional Theory: Application To The Be Atom, A. Holas, N. H. March, Y. Takahashi, C. Zhang
Hartree-Fock Method Posed As A Density-Functional Theory: Application To The Be Atom, A. Holas, N. H. March, Y. Takahashi, C. Zhang
Faculty of Engineering - Papers (Archive)
The Hartree-Fock ground-state energy and electron density are first shown to be derivable from a local one-body effective potential v(r). As a nontrivial example, attention is then focused on the Be atom and isoelectronic atomic ions, the wave functions being written in terms of the density amplitude and phase. Some related general comments on the two-level one-dimensional system are included; kinetic-energy density is shown to be a local functional of electron density generated by the harmonic-oscillator potential.
Theory Of The Piezo-Zeeman Effect For Shallow Acceptors In Group-Iv Semiconductors , K. J. Duff
Theory Of The Piezo-Zeeman Effect For Shallow Acceptors In Group-Iv Semiconductors , K. J. Duff
Faculty of Engineering - Papers (Archive)
Theory is presented for the energy splittings and transition intensities for a single hole system initially of Td symmetry which is then subject to the simultaneous application of a uniaxial stress and uniform magnetic field. Four combinations of stress and field directions are considered.
Discussion And Authors Closure On Performance Of Test Embankment Constructed To Failure On Soft Clay, Buddhima Indraratna
Discussion And Authors Closure On Performance Of Test Embankment Constructed To Failure On Soft Clay, Buddhima Indraratna
Faculty of Engineering - Papers (Archive)
Extract: RESPONSE TO DISCUSSION BY SlEW-ANN TAN It has been explained in the paper (page 18) that the Cam-clay parameters have been selected so that the undrained experimental stress-strain curve coincides with the undrained predictions from the modified Cam-clay theory. The method of parameter estimation proposed by Britto and Gunn (1987) is most appropriate if the conditions of associated flow rule and the normally consolidated behavior are satisfied... RESPONSE TO DISCUSSION BY E. W. BRAND Brand has correctly recognized the difference between the findings of the current study and previous predictions given elsewhere by Balasubramaniam et al. (1989). The authors …
High-Field Zeeman Effect Of Shallow Acceptors In Germanium , P. Fisher, G. J. Takacs, R. Vickers, A. D. Warner
High-Field Zeeman Effect Of Shallow Acceptors In Germanium , P. Fisher, G. J. Takacs, R. Vickers, A. D. Warner
Faculty of Engineering - Papers (Archive)
Zeeman absorption spectra have been obtained for B and Ga in Ge for B∥〈100〉 in the Voigt configuration with plane-polarized radiation. All twelve allowed transitions were observed for both the G and D lines. The corresponding excited states of these two lines for both impurities behave identically; two recent theoretical results are in good agreement. The measurements are a sensitive probe of the ground states; there are differences between the behavior of these for the two acceptors.
The Concept And Design Of Programmable Array Manipulator, Philip Ciufo, Fazel Naghdy, Christopher D. Cook, Pak Chung Wong
The Concept And Design Of Programmable Array Manipulator, Philip Ciufo, Fazel Naghdy, Christopher D. Cook, Pak Chung Wong
Faculty of Engineering - Papers (Archive)
This paper is the complement to the Programmable Array Manipulator, Part 1. It presents an overview of the R & D program associated with the development of the PAM. The aspects of the control scheme are given as are some experimental results showing the preliminary capabilities of the PAM.
Systems Of Illative Combinatory Logic Complete For First Order Propositional And Predicate Calculus, Henk Barendregt, Martin Bunder, Wil Dekkers
Systems Of Illative Combinatory Logic Complete For First Order Propositional And Predicate Calculus, Henk Barendregt, Martin Bunder, Wil Dekkers
Faculty of Engineering and Information Sciences - Papers: Part A
Illative combinatory logic consists of the theory of combinators or lambda calculus extended by extra constants (and corresponding axioms and rules) intended to capture inference. The paper considers systems of illative combinatory logic that are sound for first-order propositional and predicate calculus. The interpretation from ordinary logic into the illative systems can be done in two ways: following the propositions-as-types paradigm, in which derivations become combinators or, in a more direct way, in which derivations are not translated. Both translations are closely related in a canonical way. The two direct translations turn out to be complete. The paper fulfills the …
Molecular Epidemiology Of Escherichia Coli 0157:H7 Strains By Bacteriophage A Restriction Fragment Length Polymorphism Analysis: Application To A Multistate Foodborne Outbreak And A Day-Care Center Cluster, Mansour Samadpour, Linda M. Grimm, B Desai, Dalia Alfi, Jerry E. Ongerth, Phillip I. Tarr
Molecular Epidemiology Of Escherichia Coli 0157:H7 Strains By Bacteriophage A Restriction Fragment Length Polymorphism Analysis: Application To A Multistate Foodborne Outbreak And A Day-Care Center Cluster, Mansour Samadpour, Linda M. Grimm, B Desai, Dalia Alfi, Jerry E. Ongerth, Phillip I. Tarr
Faculty of Engineering and Information Sciences - Papers: Part A
Genomic DNAs prepared from 168 isolates of Escherichia coli 0157:H7 were analyzed for restriction fragment length polymorphisms on Southern blots probed with bacteriophage A DNA. The isolates analyzed included strains from a recent large multistate outbreak of E. coli 0157:H7 infection associated with consumption of poorly cooked beef in restaurants, a day-care center cluster, and temporally and geographically unrelated isolates. E. coli 0157:H7 isolates recovered from the incriminated meat and from 61 (96.8%) of 63 patients from Washington and Nevada possessed identical A restriction fragment length patterns. The A restriction fragment length polymorphisms observed in 11 (91.7%) of 12 day-care …
Markov Pyramid Models In Image Analysis, Jennifer L. Davidson, Noel A. Cressie
Markov Pyramid Models In Image Analysis, Jennifer L. Davidson, Noel A. Cressie
Faculty of Engineering and Information Sciences - Papers: Part A
The use of statistical pattern recognition techniques in image processing has led to simplifying assumptions on the statistical interdependence of the pixel value of an image, which allow theoretical analysis and/or computational implementation to be achieved. For instance, the assumption of statistical independence of the values or that their joint distributions are multivariate normal, simplifies the analysis enormously. However, these results are very limiting in representing models for data, and do not allow for analysis of arbitrary spatial dependencies, in the data. One method for modeling two-dimensional data on a lattice array has been developed by Abend et al. called …
Stochastic Recognition Of Closed Object Boundaries In Images, J Helterbrand, Noel A. Cressie
Stochastic Recognition Of Closed Object Boundaries In Images, J Helterbrand, Noel A. Cressie
Faculty of Engineering and Information Sciences - Papers: Part A
Engineering-based edge detection techniques generally use local intensity information to identify whether a pixel location is part of a boundary. Boundaries are presumed present where sharp transitions in the observed intensities occur. Unfortunately, these approaches are sensitive to error and hidden partial boundaries, which hinders the determination of closed object boundaries. In this research, a method to obtain statistically optimal closed object boundaries is presented.