UScholar Works
 
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401 - 425 of 924
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CreatorTitleDescriptionSubjectDate
401 Symko, Orest GeorgeMagnetic shielding and relaxation characteristics of superconducting YBa2Cu3O7 tubesHigh-7c superconducting tubes have been developed for magnetic shielding of SQUIDs at 77 K. The characteristics of such tubes show that adequate shielding exists for magnetic fields up to a critical field determined by the current density of the tube. Relaxation phenomena with two different time de...YBa2Cu3O7 tubes; High-Tc; SQUID1989
402 Mattis, Daniel C.Magnetic susceptibilities of finite Ising chains in the presence of defect sitesAny antiferromagnet with zero net magnetic moment exhibits limited response to an external homogeneous magnetic field. This changes dramatically in the presence of defect sites, even those that carry no spin. We examine the excess susceptibilities, longitudinal and transverse, due to one or more d...Antiferromagnets; Defects; Ising chain; Longitudinal field; Transverse field2007-12
403 Rogachev, AndreyMagnetic-field dependent differential capacitance of polymer diodesUsing admittance spectroscopy, we found that bipolar organic diodes based on pi-conjugated polymer, 2-methoxy-5-(20-ethylhexyloxy), MEH-PPV, have strong divergent contribution to the device differential capacitance. It is positive at low bias voltages, turns negative at intermediate biases, and beco...2012-01-01
404 Rogachev, AndreyMagnetic-field enhancement of superconductivity in ultranarrow wiresWe study the effect of an applied magnetic field on sub-10-nm wide MoGe and Nb superconducting wires. We find that magnetic fields can enhance the critical supercurrent at low temperatures, and do so more strongly for narrower wires. We conjecture that magnetic moments are present, but their pair-...Ultranarrow wires; Magnetic-field enhancement2006-09
405 Vardeny, Zeev ValentineMagnetic-field-dependent carrier injection at La2/3Sr1/3MnO3/ and organic semiconductors interfacesWe have fabricated organic diodes utilizing several ∏-conjugated organic semiconductors (OSEC) as spacer layers between La2=3Sr1=3MnO3 (LSMO) and various metallic electrodes, and measured their magnetoresistance (MR) and magnetoelectroluminescence (MEL) responses. The devices exhibit large negat...Organic diodes; pi-conjugated organic semicondutors; OSEC; LSMO; MR; Magnetoelectroluminescence; MEL2005-07
406 Mattis, Daniel C.Magnetization of Ising model in nonzero magnetic fieldKnowing only the zero-field magnetization (e.g., Yang's result) of the Ising model in any number of dimensions, one can construct a lower bound on m(h), the magnetization in finite field. Knowledge of u, the internal energy per bond, enables a more efficient lower bound to be constructed. Both are ...Magnetization; Griffiths inequality1969
407 Vardeny, Zeev ValentineMagneto-optical studies of photoexcitations in C61We have used a variety of cw optical and optically detected magnetic-resonance techniques to characterize long-lived photoexeitations in methanofullerene (C6 1) as a dispersion in polystyrene glass, at temperatures below 10 K. We identify triplet excitons with zero-field-splitting (ZFS) parameters...Photoexcitations; C61; Methanofullerene1993-12
408 Vardeny, Zeev ValentineMagnetoconductance response in unipolar and bipolar organic diodes at ultrasmall fieldsWe measured magnetoconductance (MC) response in a number of unipolar and bipolar organic diodes based on rr-conjugated polymers and small molecules at fields |B|< 100 mT and various bias voltages and temperatures. Similar to magneto-electroluminescence, the MCðBÞ response in bipolar diodes shows a...2010-08
409 Wu, Yong-ShiManifestations of Berry's topological phase for the photonRecently, Berry recognized in quantum mechanics a topological phase factor arising from the adiabatic transport of a system around a closed circuit, which is essentially the Aharonov-Bohm effect in parameter space. Here we consider manifestations of this phase factor for a photon in a state of adia...Aharonov-Bohm effect; Optical fibers; Waveguide1986-08
410 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
411 Dawson, KyleMasses of high-redshift clusters via SZ effect observationsWe present Sunyaev-Zel'dovich Effect (SZE) observations of distant, highly X-ray luminous clusters of galaxies. We use the SZE data to constrain their total masses, independent of X-ray observations. To do this, we assume the clusters have the same gas mass fraction as that derived from SZE measure...Sunyaev-Zel'dovich Effect; X-rays; Redshift2002
412 Wu, Yong-ShiMassless fermions and Kaluza-Klein theory with torsionA pure Kaluza-Klein theory contains no massless fermion in four-dimensional theory. We investigate the effect of introducing torsion on the internal manifold and find that there are massless fermions. The hope is that given an isometry group the representation to which these fermions belong is fixe...Massless fermions; Four-dimensional theory; Torsion1984
413 Wu, Yong-ShiMaster ward identity for nonlocal symmetries in D = 2 principal chiral modelsWe derive, in path integral approach, the (anomalous) master Ward identity associated with an infinite set of nonlocal conservation laws in two-dimensional principal chiral models.1997-11
414 Wu, Yong-ShiMatrix compactification on orientifoldsGeneralizing previous results for orbifolds, in this paper we describe the compactification of the matrix model on an orientifold which is a quotient space Rd/G as a Yang-Mills theory residing on a quantum space. The information of the compactification is encoded in the action of the discrete symmet...Spacetime; Orientifolds; Compactification; Quantum space1999-06
415 Mattis, Daniel C.Mattis and Pan replyAfter several independent calculations failed to confirm our published1 numbers on the ground-state energy of the s = 1/2 antiferromagnet in two dimensions, we checked our computer programs and found some deplorable errors introduced in proceeding from one dimension to two.Ground-state energy; Antiferromagnets; Long-range order1988
416 Sokolsky, PierreMeasurement of elastic νμ and ν̄μ scattering on protonsWe have measured elastic vµ and vµ scattering on protons at the Brookhaven National Laboratory Alternating Gradient Synchrotron. We find RNC = σ (νµp → vµp)/σ (vµp -* vµp) = 0.44 ±0.12 and Rvµ = σ (vµp → vµp)/σ (vµn → µ-p) =0.11 ±0.03. The elastic Q2 distribution is in good a...1981-09
417 Williams, Clayton C.Measurement of in-plane magnetization by force microscopyWe present data which show that the magnetic force microscope is capable of detecting the component of the magnetic field parallel to the surface of a sample under study. Images of bits in a Co-alloy thin-film disk and of laser-written bits in a TbFe film were taken with a magnetized tip tilted at ...Co-alloy disc; Magnetization1988
418 Sokolsky, PierreMeasurement of the flux of ultra high energy cosmic rays by the stereo techniqueThe High Resolution Fly's Eye (HiRes) experiment has measured the flux of ultrahigh energy cosmic rays using the stereoscopic air fluorescence technique. The HiRes experiment consists of two detectors that observe cosmic ray showers via the fluorescence light they emit. HiRes data can be analyzed i...Ultrahigh energy cosmic rays; Fluorescence; Energy spectrum; GZK cutoff2009-08
419 Kieda, David B.; Bergman, Douglas R.; Sokolsky, PierreMeasurement of the flux of ultrahigh energy cosmic rays from monocular observations by the high resolution fly's eye experimentWe have measured the cosmic ray spectrum above 10^172 eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode.We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors.We ...High Resolution Fly's Eye; Ultrahigh energy cosmic rays2004-04
420 Sokolsky, PierreMeasurement of the flux of ultrahigh energy cosmic rays from monocular observations by the High Resolution Fly's Eye experimentWe have measured the cosmic ray spectrum above 1017.2 eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode.We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors.We fi...Extensive air showers; Fluorescence; Energy spectrum2004-04
421 Gondolo, PaoloMeasurement of the gluon parton distribution function at small x with neutrino telescopesWe analyze the possibility that neutrino telescopes may provide an experimental determination of the slope λ of the gluon distribution in the proton at momentum fractions x smaller than the accelerator reach. The method is based on a linear relation between λ and the spectral index (slope) of th...Neutrino telescopes; Charm2001-01
422 Gerton, JordanMeasurements of collective collapse in a Bose-Einstein condensate with attractive interactionsThe occupation number of a magnetically trapped Bose-Einstein condensate is limited for atoms with attractive interactions. It has been predicted that, as this limit is approached, the condensate will collapse by a collective process. The measured spread in condensate number for samples of 7Li atom...1999-02
423 DeTar, CarletonMeasuring the hadronic spectrum of the quark plasmaIn an effort to characterize the large-scale structure and composition of the Q C D plasma at zero baryon-number density in the vicinity of the high-temperature phase transition, we have carried out a numerical simulation in SU(3) lattice gauge theory with four flavors of low-mass staggered fermions...Quark plasma; Gluon plasma; Hadronic matter; Deconfinement; Chiral symmetry; Phase transitions1987-11
424 Gondolo, PaoloMeasuring the prompt atmospheric neutrino flux with down-going muons in neutrino telescopesIn the TeV energy region and above, the uncertainty in the level of prompt atmospheric neutrinos would limit the search for diffuse astrophysical neutrinos. We suggest that neutrino telescopes may provide an empirical determination of the flux of prompt atmospheric electron and muon neutrinos by mea...Neutrino telescopes; Prompt flux2003-01
425 Vardeny, Zeev ValentineMechanically stretchable and reversibly deformable liquid metal-based plasmonicsWe demonstrate that liquid metals are attractive materials for active plasmonic devices at terahertz frequencies. Using a liquid metal injected into an elastomeric mold, we measure the static and stretched transmission properties of aperture arrays.2012-01-01
401 - 425 of 924