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Creator | Title | Description | Subject | Date |
151 |
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Vardeny, Zeev Valentine | Magnetic field effects in ∏-conjugated polymer-fullerene blends: evidence for multiple components | We studied magnetoconductance (MC) and magnetoelectroluminescence (MEL) in organic diodes from blends of ∏-conjugated polymers and fullerenes at various concentrations, c. The MC response is composed of several components that depend on the applied bias voltage and c. A dominant positive low-field... | pi-conjugated polymers; Fullerene blends; Magnetic field effects; Magnetoconductance; Magnetoelectroluminescence; MC; MEL; Organic magnetoresistance; OMAR; Organic diodes | 2008-12 |
152 |
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Vardeny, Zeev Valentine | Photoexcitation dynamics in regioregular and regiorandom polythiophene films | Using a variety of optical probes techniques we studied the photoexcitation dynamics in thin films of poly-3-hexyl thiophene with regioregular order that forms lamellae structures with increased interchain interaction, as well as regiorandom order that keeps a chainlike morphology. In regiorandom fi... | Photoexcitation dynamics; Regio-regular; Regio-random; Polythiophene films | 2001-11 |
153 |
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Wu, Yong-Shi | Multisheet configuration space and fractional quantum statistics | We show that if one uses a multisheet configuration space for a system of identical particles, then fractional quantum statistics in two dimensions can be geometrically characterized as a topological quantum number for going from one sheet to the next. Furthermore, the spectrum of such a g-sheet s... | | 1992-05 |
154 |
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Williams, Clayton C. | High-resolution photothermal laser probe | An advance in photothermal imaging is described. A photothermal laser probe is presented that operates at a frequency of 1 GHz. At this frequency the spacial resolution is limited only by the optical spot size of the probe beam. The photothermal sensitivity of the probe is 1.2 X 10-4 degrees Celsiu... | Laser probes | 1985 |
155 |
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Vardeny, Zeev Valentine | Random lasing in human tissues | A random collection of scatterers in a gain medium can produce coherent laser emission lines dubbed "random lasing." We show that biological tissues, including human tissues, can support coherent random lasing when infiltrated with a concentrated laser dye solution. To extract a typical random reson... | Random lasing; Gain medium; Human tissues; Malignant tissues | 2004 |
156 |
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Wu, Yong-Shi | Quiver matrix mechanics for IIB string theory (II): generic dual tori, fractional matrix membrane and SL(2, Z) duality | With the deconstruction technique, the geometric information of a torus can be encoded in a sequence of orbifolds. By studying the Matrix Theory on these orbifolds as quiver mechanics, we present a formulation that (de)constructs the torus of generic shape on which Matrix Theory is "compactified". T... | | 2005-02 |
157 |
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Symko, Orest George | Spin-glass transition of a dilute Ag-Mn alloy in a magnetic field | The spin-glass state in a magnetic field is studied in a very dilute Ag-Mn sample containing 150 ppm of Mn. The field-cooled magnetization of this system is investigated over temperatures ranging from 4 down to 0.01 K in magnetic fields from 932 to 1 Oe. Scaling is observed in the nonlinear suscepti... | Spin-glass transition; Spin-glass state; Ag-Mn alloy; Silver-manganese alloy | 1986-01 |
158 |
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DeTar, Carleton | Lattice calculation of 1-+ hybrid mesons with improved Kogut-Susskind fermions | We report on a lattice determination of the mass of the exotic 1-+ hybrid meson using an improved Kogut-Susskind action. Results from both quenched and dynamical quark simulations are presented. We also compare with earlier results using Wilson quarks at heavier quark masses. The results on lattice... | Staggered quarks; Kogut-Susskind fermions | 2003-10 |
159 |
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Vardeny, Zeev Valentine | Laser action in polydialkylfluorene films: influence of low-temperature thermal treatment | We have used a variety of optical probes to investigate the changes occurring upon low-temperature thermal treatment to the emissive properties of dialkyl substituted polyfluorene thin films. We found that the low-temperature-driven morphological changes involving aggregates formation, which are ob... | Laser action; Polydialkylfluorene films; pi-conjugated polymers; Thermal treatment | 1999 |
160 |
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Dawson, Kyle | Radiation tolerance of fully-depleted P-channel CCDs designed for the SNAP satellite | Thick, fully depleted p-channel charge-coupled devices (CCDs) have been developed at the Lawrence Berkeley National Laboratory (LBNL). These CCDs have several advantages over conventional thin, n-channel CCDs, including enhanced quantum efficiency and reduced fringing at near-infrared wavelengths an... | P-Channel CCDs; SNAP satellite; Space-based telescopes | 2008-06 |
161 |
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Gondolo, Paolo | AGAPEROS: searching for microlensing in the LMC with the pixel method. I. Data treatment and pixel light curves production | Recent surveys monitoring millions of light curves of resolved stars in the LMC have discovered several microlensing events. Unresolved stars could however signi _x000C_cantly contribute to the microlensing rate towards the LMC. Monitoring pixels, as opposed to individual stars, should be able to ... | Data analysis techniques; Halo; Galaxies; Gravitational lensing; Pixel method; Large Magellanic Cloud; LMC | 1999 |
162 |
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Gerton, Jordan | Dipolar relaxation collisions in magnetically trapped 7Li | We report the measurement of the rate constant for dipolar relaxation from the (F=2, mF=2) hyperfine state of 7Li. The atoms are confined in a permanent magnet trap at a field of 10^3 G. The measured value of (1.05±0.10)X10^-14 cm3/s agrees well with theory. Additionally, we determine an upper bo... | | 1999-02 |
163 |
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Symko, Orest George | Tunneling studies of mesoscopic all-NBN junctions | A scanning tunneling microscope (STM) was used to position a NbN tip near a NbN thin film sputtered on a Si substrate. Measurements at 4.2 K clearly show an energy gap of 5.0 mV. The Coulomb blockade of tunneling and the Coulomb staircase, formed by single-electron charging of the central electrod... | All-NbN junctions; NbN | 1993-03 |
164 |
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Vardeny, Zeev Valentine; Symko, Orest George | Quasiparticle relaxation in high-Tc superconductor | Recent measurements by Eesley et al. [1] of transient reflectivity in superconducting Tl2Ba2Ca2Cu30io were interpreted as evidence for order-parameter relaxation in the vicinity of Tc, which was analyzed in terms of BCS weak coupling for ?(r)/?(0). In this Comment we question this interpretation ... | Quasiparticle relaxation | 1991 |
165 |
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Gondolo, Paolo | Stellar orbit constraints on neutralino annihilation at the galactic center | Dark matter annihilation has been proposed to explain the TeV gamma rays observed from the Galactic Center. We study constraints on this hypothesis coming from the mass profile around the Galactic Center measured by observing stellar dynamics. We show that for several proposed WIMP candidates, the... | Neutralinos; Annihilation | 2006-09 |
166 |
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Vardeny, Zeev Valentine | Ultrafast spectroscopy of excitons in single-walled carbon nanotubes | We studied the femtosecond dynamics of photoexcitations in films containing semiconducting and metallic single-walled carbon nanotubes (SWNTs), using various pump-probe wavelengths and intensities.We found that confined excitons and charge carriers with subpicosecond dynamics dominate the ultrafas... | Ultrafast spectroscopy; Excitons; Single-walled carbon nanotubes; SWNT | 2004-01 |
167 |
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Gondolo, Paolo | Detectability of the Sgr dwarf leading tidal stream with Auger, EUSO, or OWL | We point out that if heavy metastable particles composing the dark matter of our galaxy are responsible for the ultrahigh energy cosmic rays (UHECR) then the leading tidal stream of the Sagittarius dwarf galaxy could be detected through UHECR. The signal would be an anisotropy in the UHECR flux sma... | Sagittarius dwarf galaxy; Sgr stream; anisotropy | 2004-07 |
168 |
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Sokolsky, Pierre | First observation of the Greisen-Zatsepin-Kuzmin suppression | The High Resolution Fly's Eye (HiRes) experiment has observed the Greisen-Zatsepin-Kuzmin suppression (called the GZK cutoff) with a statistical significance of five standard deviations. HiRes' measurement of the flux of ultrahigh energy cosmic rays shows a sharp suppression at an energy of 6 x 10^1... | Extensive air showers; Suppression; Energy spectrum; Fluorescence; GZK cutoff | 2008-03 |
169 |
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DeTar, Carleton | Equation of state for two flavor QCD at Nt=6 | We calculate the two flavor equation of state for QCD on lattices with lattice spacing a=(6T)21 and find that cutoff effects are substantially reduced compared to an earlier study using a=(4T)21. However, it is likely that significant cutoff effects remain. We fit the lattice data to expected forms ... | Phase transitions; Quark-gluon plasma; Dynamical quarks | 1997-06 |
170 |
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Symko, Orest George | Background signals in SQUID magnetometers | Since a SQUID magnetometer is an extremely sensitive device capable of detecting minute magnetic flux changes in a sample, it will also detect unwanted signals from materials near the magnetometer. The presence of temperature dependent "background signals" limits the accuracy of measurements of ... | SQUID magnetometer; Background signals | 1974 |
171 |
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Symko, Orest George | Spin-glass behavior in dilute magnetic alloys with hcp structure | A simple physical model is presented for calculating the magnetization of dilute magnetic systems with hep hosts which incorporates elements of both crystal-field theory and the molecular-field theory of spin-glasses. To permit the computation of the Ruderman-Kittel-Kasuya-Yosida contribution, the i... | Spin-glass behavior; HCP structure; HCP alloys; Dilute magnetic systems; Molecular-field theory; MgMn; ZnMn | 1982-05 |
172 |
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Gerton, Jordan | Phase-contrast imaging of atomic superfluid state in degenerate gas of 6Li atoms | The recent experimental realizations of Bose-Einstein condensation in trapped ultracold atomic gases composed of bosonic alkali atoms has generated a broad interest in studying different properties of these degenerate atomic Bose systems. Although the degenerate atomic gas composed of fermionic atom... | | 1998 |
173 |
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Mattis, Daniel C. | Phonons and phase transitions of helium | We find a new collective shear-wave-like mode above Tλ, merging with the longitudinal acoustic mode at a higher critical temperature. The speed of the new sound wave is predicted to vanish near Tλ as s ∞ (T -Tλ)½ . | | 1973-06 |
174 |
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Vardeny, Zeev Valentine | Detection of electronic excited states in conjugated polymers by picosecond transient strain spectroscopy | We describe a new type of spectroscopy based on picosecond transient strain in absorption photomodulation that can be used to detect and identify both allowed and forbidden optical transitions in solid thin films. We have applied the new spectroscopy to a variety of conducting polymer films such as ... | Picosecond transient strain spectroscopy | 1995-02 |
175 |
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Vardeny, Zeev Valentine | Magneto-optical studies of photoexcitations in C61 | We 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; Methanofullerene | 1993-12 |