UScholar Works
 
Filters: Collection: "ir_uspace" School Or College: "College of Science" Type: "Text" Format: "application/pdf"
276 - 300 of 1,922
Number of results to display per page
CreatorTitleDescriptionSubjectDate
276 Vardeny, Zeev ValentineTransient-photomodulation-spectroscopy studies of carrier thermalization and recombination in α-Si:HThe transient response of mid-gap absorption in a-Si:H to pulsed optical excitation is studied as a function of time (300 ns to 30 ms) and sample temperature (10-220 K) with use of probe wavelengths ranging from 0.75 to 5.5 fim. A numerical inversion process applied to the data gives the distributio...Amorphous silicon; a-Si:H; Transient-photomodulation-spectroscopy; Carrier thermalization; Carrier recombination; Pulsed optical excitation1988-07
277 Gondolo, PaoloIndirect detection of dark matter in km-size neutrino telescopesNeutrino telescopes of kilometer size are currently being planned. They will be two or three orders of magnitude bigger than presently operating detectors, but they will have a much higher muon energy threshold. We discuss the trade-off between area and energy threshold for indirect detection of neu...Neutrino telescopes; Energy threshold; Neutralino annihilations; Supersymmetric models1998-11
278 Lupton, John MarkDevice model for polymer light emitting diodes: effect of temperature and oxidationWe present a temperature-dependent single carrier device model for polymer light-emitting diodes. The model includes both the injection of charge carriers over a barrier and the transport of charges across the device. To test the model, the temperature dependence of an LED based on the conjugated po...Single carrier; Temperature dependent; Poly(phenylene vinylene); Transport measurements; ITO; Disorder1999
279 Seger, JonConditional relatedness, recombination, and the chromosome numbers of insectsIf two polymorphic loci are out of phase equilibrium, a homozygote at one of these loci is more highly related to its kin, at the other locus, than is an equivalent heterozygote. As a result, selection can favor (1) phenotypic responses to relative heterozygosity, and (2) increased recombination bet...Coefficients of relatedness; Conditional relatedness1983
280 Vardeny, Zeev ValentinePhotoresponse and electroresponse of polymers light emitting diodesWe have studied the photoresponse and electroresponse of light emitting diodes (LEDs ) made from a variety of soluble conducting polymers sandwiched between indium tin oxide (ITO) and metals including calcium, aluminum and copper. Under illumination all freshly prepared LEDs exhibit relatively large...Photoresponse; Electroresponse; Photovoltage; I-V curves1995
281 Ailion, David CharlesNuclear double resonance: cross relaxation rates between two spin speciesA rotating-frame nuclear-double-resonance experiment is reported in which the cross-relaxation rates between 7Li and 6Li in powdered lithium metal were measured. The theory developed my McArthur, Hahn, and Walstedt (MHW) is applied to these data and good agreement is obtained. We also apply this t...Nuclear-double-resonance; Lithium; MHW; Cross-relaxation1977
282 Goller, FranzLateralization as a symmetry breaking process in birdsongThe singing by songbirds is a most convincing example in the animal kingdom of functional lateralization of the brain, a feature usually associated with human language. Lateralization is expressed as one or both of the bird's sound sources being active during the vocalization. Normal songs require ...Lateralization; Syringeal muscles; Respiration; Gating2007-03
283 Saam, BrianUniversal long-time behavior of nuclear spin decays in a solidMagnetic resonance studies of nuclear spins in solids are exceptionally well suited to probe the limits of statistical physics. We report experimental results indicating that isolated macroscopic systems of interacting nuclear spins possess the following fundamental property: spin decays that start ...Nuclear spin decays; Hyperpolarized solid xenon; Chaos2008-08
284 Boehme, ChristophSpin-dependent processes at the crystalline Si-SiO2 interface at high magnetic fieldsAn experimental study on the nature of spin-dependent excess charge-carrier transitions at the interface between (111)-oriented phosphorous-doped ([P]) ~ 1015 cm−3) crystalline silicon and silicon dioxide at high magnetic field (B0~8.5 T) is presented. Electrically detected magnetic-resonance (E...Silicon interfaces; Spin-dependent recombination2008-07
285 Symko, Orest GeorgeObservation of a narrow pseudogap near the Fermi level of AlCuFe quasicrystalline thin filmsWe present the first experimental determination by tunneling spectroscopy of the density of states (DOS) close to the Fermi energy of AlCuFe quasicrystalline thin film samples. The measurements show that the Fermi level in a quasicrystal lies in a deep narrow pseudogap 60 m e V wide. Above an applie...AlCuFe; Quasicrystalline thin films; Pseudogap; Fermi level; Density of states; DOS1995-05
286 Boehme, ChristophUltra-sensitive electrical detection of spin Rabi oscillation at paramagnetic defectsA short review of the pulsed electrically detected magnetic resonance (pEDMR) experiment is presented. PEDMR allows the highly sensitive observation of coherent electron spin motion of charge carriers and defects in semiconductors by means of transient current measurements. The theoretical foundatio...Rabi oscillations; Electron spin resonance; Paramagnetic defects2006-04
287 Capecchi, Mario R.Measurement of suppressor transfer RNA activity.Transfer RNA (tRNA) suppression of nonsense mutations in prokaryotic systems has been widely used to study the structure and function of different prokaryotic genes. Through genetic engineering techniques, it is now possible to introduce suppressor (Su+) tRNA molecules into mammalian cells. A quanti...Animals; Cells, Cultured; Eukaryotic Cells; Genes, Viral; Mice; Orthomyxoviridae; Peptide Chain Termination, Translational; Protein Biosynthesis1983-08-26
288 Miller, Joel StevenPotential technology directions of molecular metalsIn the past decade, anisotropic molecular conductors have been found which possess unusual electrical, optical, magnetic, and in some cases mechanical properties. Exploiting these properties for specific devices is inevitable, and a number of diverse applications of molecular metals have been repor...Molecular metals1979
289 Beckerle, Mary C.Zyxin and cCRP: Two interactive LIM domain proteins associated with the cytoskeletonInteraction with extracellular matrix can trigger a variety of responses by cells including changes in specific gene expression and cell differentiation. The mechanism by which cell surface events are coupled to the transcriptional machinery is not understood, however, proteins localized at sites o...Zyxin; Cysteine-rich proteins; cCRP; LIM domain1992
290 Hughes, Kelly T.; Chevance, FabienneMechanism of outer membrane penetration by the eubacterial flagellum and implications for spirochete evolutionThe rod component of the bacterial flagellum polymerizes from the inner membrane across the periplasmic space and stops at a length of 25 nm at the outer membrane. Bushing structures, the P- and L-rings, polymerize around the distal rod and form a pore in the outer membrane. The flagellar hook stru...Flagellar assembly; Spirochete evolution; Membrane penetration2007
291 Davidson, Diane W.Tropical arboreal ants: why so abundant?ANTS ARE AMONG the most numerous and readily observed arthropods of tropical forests. Indeed, based on their standing biomass and many effects on other species, ants (Formicidae) are arguably the dominant arthropod family in the canopies of lowland rain forest trees (Tobin 1995). Others have tried t...Arboreal ants; Tropics1996
292 Armentrout, Peter B.Probes of spin conservation in heavy metal reactions: experimental and theoretical studies of the reactions of Re+ with H2, D2, and HDA guided ion beam tandem mass spectrometer is used to examine the kinetic energy dependence of reactions of the third-row transition metal cation, Re1, with molecular hydrogen and its isotopologues. A flow tube ion source produces Re1 in its 7S3 electronic ground state.Endothermic reactions; Transition metal ions; Rhenium ions; Dihydrogen2004
293 Beckerle, Mary C.Targeting of zyxin to sites of actin membrane interaction and to the nucleusThe localization of proteins to particular intracellular compartments often regulates their functions. Zyxin is a LIM protein found prominently at sites of cell adhesion, faintly in leading lamellipodia, and transiently in cell nuclei. Here we have performed a domain analysis to identify regions in ...Zyxin; Actin; LIM domains; Focal adhesions; Lamellipodia; Cytoskeletal architecture2001
294 Wu, Yong-ShiTowards a noncommutative geometric approach to matrix compactificationIn this paper we study generic M(atrix) theory compactifications that are specified by a set of quotient conditions. A procedure is proposed which both associates an algebra to each compactification and leads deductively to general solutions for the matrix variables. The notion of noncommutative g...Matrix theory; Compactification; Noncommutativity; Orbifolds; Orientifolds; Spacetime; Klein bottle; Gauge theory; Torus1998-07
295 Williams, Clayton C.Mapping of mobile charges on insulator surfaces with the electrostatic force microscopeMigration of surface ions in lateral fields on insulator surfaces may modify the electrical characteristics of underlying semiconductor structures causing device instabilities. A high sensitivity electrostatic force microscope is used to image the movement and spatial distribution of surface ions on...Insulator surfaces; Surface ions; Electrostatic force microscope1993
296 Vardeny, Zeev ValentinePhonon anomalies in Cu halidesA great number of the observed phonon anomalies in the zinc-blende phase of Cu-halide crystals are explained by means of a dynamical model. It is assumed that a Cu ion populates four equivalent off-center sites or its ideal position. The off-center Cu+ population is temperature and pressure dependen...Phonon anomalies; Cu-halide crystals; Cuprous halides1979-03
297 Sokolsky, PierreEvidence for correlated changes in the spectrum and composition of cosmic rays at extremely high energiesThe Utah Fly's Eye detector has revealed a change in the cosmic ray composition which is correlated with structure in the all-particle energy spectrum. The data can be fitted by a simple model of a steep power law spectrum of heavy nuclei which is overtaken at high energies by a flatter spectrum of ...Energy spectrum; Extensive air showers1993-11
298 Armentrout, Peter B.Thermodynamics of ammonia activation by iron cluster cations: guided ion beam studies of the reactions of Fen+ (n=2-10,14) with ND3The kinetic energy dependences of the reactions of Fen 1 (n52 - 10,14) with ND3 are studied in a guided ion beam tandem mass spectrometer over the energy range of 0-10 eV. Dehydrogenation of ammonia to form FenND1 is found to be efficient and exothermic for n54 in agreement with previous FT-ICR stu...2003
299 Mishchenko, EugeneZero-bias anomaly in two-dimensional electron layers and multiwall nanotubesThe zero-bias anomaly in the dependence of the tunneling density of states n (e) on the energy e of the tunneling particle for two- and one-dimensional multilayered structures is studied. We show that for a ballistic two-dimensional (2D) system the first-order interaction correction to density of s...Spin-orbit coupling; Coulomb interaction2002-05
300 Adler, Frederick R.Virulence management in biocontrol agentsAlthough biological control is founded upon the virulence of natural enemies to the targeted pests, there has been little effort to understand how this might change, let alone to manage it. Frank Fenner and colleagues can be credited with being the first (and last!) to monitor changes in virulence ...Pathogens; Management; Natural2002
276 - 300 of 1,922