UScholar Works
 
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326 - 350 of 924
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CreatorTitleDescriptionSubjectDate
326 Lupton, John MarkHyperfine-field-mediated spin beating in electrostatically bound charge carrier pairsOrganic semiconductors offer a unique environment to probe the hyperfine coupling of electronic spins to a nuclear spin bath. We explore the interaction of spins in electron-hole pairs in the presence of inhomogeneous hyperfine fields by monitoring the modulation of the current through an organic li...Spin beating; Electrostatically-bound; Charge carrier pairs; Electronic spins; Nuclear spin bath; Organic light-emitting diodes2010-01
327 Wu, Yong-ShiIdentification of androgen response elements in the insulin-like growth factor I upstream promoterTestosterone stimulates the expression of IGF-I in cells and tissues that include prostate, muscle and muscle satellite cells, and the uterus. Here, the molecular mechanisms of this effect of testosterone were explored. Testosterone increased IGF-I mRNA levels in HepG2 and LNCaP cells and stimulated...IFG-I; Androgen-responsive elements2007
328 Vardeny, Zeev Valentine; Ehrenfreund, Eitan A.Illumination-induced metastable polaron-supporting state in poly(p-phenylene vinylene) filmsWe found an illumination-induced metastable polaron-supporting state in films of a soluble derivative of poly-p-phenylene vinylene (MEH-PPV). Pristine, nonilluminated MEH-PPV polymer films do not show longlived photogenerated polarons. Prolonged UV illumination, however, is found to induce a revers...Metastable polaron-supporting state; Poly(p-phenylene vinylene); PPV; MEH-PPV; Excitons2007-07
329 Wu, Yong-ShiImplications of a cosmological constant varying as R-2We advocate the possibility that the (effective) cosmological constant A varies in time as R- 2, R being the scale factor of our expanding Universe. This behavior can be obtained under some simple and general assumptions in conformity with quantum cosmology. After pointing out several advantages w...Cosmological constant1990-01
330 Mattis, Daniel C.Implications of infrared instability in a two-dimensional electron gasWe consider the tight-binding energy band in sq lattices and determine that in the half-filled case there exists an infrared instability in addition to the 2kF (nesting)-type instability. In view of the pseudo-two-dimensional band structure of La2-xBaxCu04 recently proposed by Jorgensen et al. and b...Fermi surface; Bosonization1987-07
331 Gondolo, PaoloImplications of muon anomalous magnetic moment for supersymmetric dark matterThe anomalous magnetic moment of the muon has recently been measured to be in conflict with the standard model prediction with an excess of 2.6s. Taking the excess at face value as a measurement of the supersymmetric contribution, we find that at 95% confidence level it imposes an upper bound of 50...Magnetic moment; Neutralinos2001-05
332 Mattis, Daniel C.Improved Landau-Ginzburg equation near surfaces of solidsWe study the order parameter near the surface for an Ising model. Applications to the lattice gas, alloy problem, and ferromagnetism are noted. Away from Tc our equations differ from the Landau-Ginzburg results due to an additional nonlinear, term which can substantially affect the order parameter...Landau-Ginzburg equation; Boundary conditions1980-12
333 Gondolo, PaoloImproved constraints on supersymmetric dark matter from muon g-2The new measurement of the anomalous magnetic moment of the muon by the Brookhaven AGS experiment 821 again shows a discrepancy with the standard model value. We investigate the consequences of these new data for neutralino dark matter, updating and extending our previous work [E. A. Baltz and P. ...Magnetic moment; Neutralinos2003-03
334 Gerton, JordanImproved localization accuracy in stochastic super-resolution fluorescence microscopy by K-factor image deshadowingLocalization of a single fluorescent particle with sub-diffraction-limit accuracy is a key merit in localization microscopy. Existing methods such as photoactivated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM) achieve localization accuracies of single emitt...2014-01-01
335 DeTar, CarletonImproving flavor symmetry in the Kogut-Susskind hadron spectrumWe study the effect of modifying the coupling of Kogut-Susskind quarks to the gauge field by replacing the link matrix in the quark action by a ‘‘fat link,'' or sum of link plus three-link paths. Flavor symmetry breaking, determined by the mass difference between the Goldstone and non-Goldston...Kogut-Susskind quarks; Flavor symmetry; Fat links1997-02
336 Gondolo, PaoloIndirect detection of a subdominant density component of cold dark matterWe examine the detectability through indirect means of weakly interacting dark matter candidates that may constitute not all but only a subdominant component of galactic cold dark matter. We show that the possibility of indirect detection of neutralinos from their annihilations in the Earth and Su...WIMP; Weakly interacting massive particles; Annihilations2003-01
337 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
338 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 larger 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 ne...Neutrino telescopes; Energy threshold; Neutralino annihilations; Supersymmetric models1999
339 Gondolo, PaoloIndirect neutralino detection rates in neutrino telescopesNeutralinos annihilating in the center of the Sun or the Earth may give rise to a detectable signal of neutrinos. We derive the indirect detection rates for neutrino telescopes in the minimal supersymmetric extension of the standard model. We show that even after imposing all phenomenological and e...Neutralinos; Neutrino telescopes; Relic density; Annihilations1997-02
340 Boehme, ChristophInfluence of disorder on electrically and optically detected electron spin nutationA numerical study of the influence of disorder in semiconductors on spin-Rabi nutation observed with pulsed electrically or optically detected magnetic-resonance techniques (pEDMR and pODMR, respectively ) is presented. It is shown that transient nutation signals of disordered spin ensembles differ ...Electron spin nutations2009-02
341 Rogachev, AndreyInfluence of high magnetic fields on the superconducting transition of one-dimensional Nb and MoGe nanowiresThe effects of a strong magnetic field on superconducting Nb and MoGe nanowires with diameter ~10 nm have been studied. We have found that the Langer-Ambegaokar-McCumber-Halperin (LAMH) theory of thermally activated phase slips is applicable in a wide range of magnetic fields and describes well the ...Nb; MoGe; Superconducting transition; Langer-Ambegaokar-McCumber-Halperin; LAMH; Phase slips2005-01
342 Mishchenko, EugeneInfrared absorption and Raman scattering on coupled plasmon-phonon modes in superlatticesWe consider theoretically a superlattice formed by thin conducting layers separated spatially between insulating layers. The dispersion of two coupled phonon-plasmon modes of the system is analyzed by using Maxwell's equations, with the influence of retardation included. Both transmission for the fi...Infrared absorption; Raman scattering2006-04
343 Vardeny, Zeev ValentineInfrared ultrafast optical probes of photoexcitations in ∏-conjugated organic semiconductorsWe measured the ultrafast dynamics of photoexcitations in a variety of semiconductor ∏-conjugated polymer films and solutions, in the spectral range from 0.13 eV to 1.05 eV and time domain from 100 fs to 800 ps. The measurements were made in the low signal regime, where the relative changes in tra...Infrared ultrafast optical probes; Photoexcitations; Ultrafast dynamics; MEH-PPV2005
344 Williams, Clayton C.Instability induced tunneling and repeatable charge injection to SiO2 surfaces by electrostatic force microscopyThe dynamic response and stability of a voltage biased oscillating cantilever in the proximity of an insulating sample surface is investigated. As the tip approaches the sample surface, the cantilever can jump between two different oscillation modes. The jump is detected as an abrupt increase in t...Electrostatic force microscopy; EFM; Dielectric films2004
345 Wu, Yong-ShiIntegrable open spin chain in super Yang-Mills and the plane-wave/SYM dualityWe investigate the integrable structures in an N = 2 superconformal Sp(N) Yang-Mills theory with matter, which is dual to an open+closed string system. We restrict ourselves to the BMN operators that correspond to free string states. In the closed string sector, an integrable structure is inherited ...2004-02-01
346 Wu, Yong-ShiIntegrable spin chain and operator mixing in N = 1,2 supersymmetric theoriesWe study operator mixing, due to planar one-loop corrections, for composite operators in D = 4 supersymmetric theories. We present some N = 1, 2 Yang-Mills and Wess-Zumino models, in which the planar one-loop anomalous dimension matrix in the sector of holomorphic scalars is identified with the Hami...2004-04
347 Dawson, KyleIntensive HST survey for z > 1 type Ia supernovae by targeting galaxy clustersWe present a new survey strategy to discover and study high redshift Type Ia supernovae (SNe Ia) using the Hubble Space Telescope (HST). By targeting massive galaxy clusters at 0.9 < z < 1.5, we obtain a twofold improvement in the efficiency of finding SNe compared to an HST field survey and a facto...Cosmological parameters2009-11-01
348 Vardeny, Zeev ValentineInterchain photogeneration of charged solitons in trans-(CH)xIn a recent Letter1 Rothberg, Jedju, Etemad, and Baker (RJEB) used a novel photoinduced-absorption (PA) technique to study charged-soliton (S ?) dynamics in trans-(CH)X with picosecond resolution by measuring transient PA at 0.45 eV. Both intrachain and interchain photogeneration of S ? are rep...Interchain photogeneration; Charged solitons; Trans-(CH)x1987
349 Lupton, John MarkIntermittency in second-harmonic radiation from plasmonic hot spots on rough silver filmsSurface enhancement of electromagnetic fields in plasmonic hot spots formed on rough silver films enables the observation of second-harmonic generation (SHG) from single metal nanoparticles. Nonlinear light scattering from these particles exhibits blinking in analogy to luminescence from single qu...Harmonic radiation; Plasmonic hot spots; Second harmonic generation; SHG2009-10
350 Lupton, John MarkIntrinsic room-temperature electrophosphorescence from a π-conjugated polymerElectrically induced phosphorescence from a poly(para-phenylene) ladder-type polymer is observed for the first time and characterized using time resolved spectroscopy. Short-lived phosphorescence is also observed in gated fluorescence spectra and is found to be quenched reversibly by oxygen. Therm...pi-conjugated polymers; Electrophosphorescence; Ladder-type polymer; Gated fluorescence spectra2002-09
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