|
|
Creator | Title | Description | Subject | Date |
176 |
|
Vardeny, Zeev Valentine; Ehrenfreund, Eitan A. | Phonon spectroscopy in π-conjugated polymers; the role of the excited electronic states | The Raman active vibrational modes in 7r-conjugated polymers are known to have different frequencies in different types of experiments. The best known examples are the resonant Raman scattering (RRS) and doping or photoinduced absorption infrared active vibrations (IRAV) measurements, in which the s... | pi-conjugated polymers; Phonon spectroscopy; Resonant Raman scattering; ir-active phonons | 1997 |
177 |
|
Wu, Yong-Shi | Quantum dynamics and statistics of vortices in two-dimensional superfluids | The phase change of the wave function of a superfluid film as a vortex moves around a closed path counts the number of superfluid particles enclosed by that path. This result is used to investigate whether such vortices obey "fractional statistics." We conclude that this is not the case in compress... | Superfluid films; Vortices; Fractional statistics | 1985-12 |
178 |
|
Vardeny, Zeev Valentine; Raikh, Mikhail E. | Universal properties of random lasers | The design and fabrication of laser resonators is often difficult. However, random lasers occur in gain media with numerous scatterers and produce coherent laser emission without any predesigned cavity. The generation of coherent emission from multiple scattering is quite general and its basic prin... | Random lasers; Laser resonators; pi-conjugated polymers; Rhodamine-TiO2 suspensions; Random media; Random lasing | 2003-01 |
179 |
|
Wu, Yong-Shi | Scale and conformal invariance in Chern-Simons-matter field theory | We study perturbative renormalization of Dsss3 Chern-Simons gauge theory coupled to scalar and fermionic matter. We show that in the non-Abelian case the coefficient of the Chern-Simons term has infinite renormalization and that both the matter and the non-Abelian gauge fields acquire nonvanishing ... | Chern-Simons gauge theory; Renormalization | 1991-09 |
180 |
|
DeTar, Carleton | QCD thermodynamics with an improved lattice action | We have investigated QCD with two flavors of degenerate fermions using the Symanzik-improvement program for both the gauge and fermion actions. Our study focuses on the deconfinement transition on an Nt=4 lattice. Having located the thermal transition, we performed zero temperature simulations nea... | Wilson fermions; Polyakov loop; Chiral symmetry; Phase transitions | 1997-11 |
181 |
|
Thomas, Kirk R.; Capecchi, Mario R. | Location of crossovers during gene targeting with insertion and replacement vectors. | Gene targeting was used to introduce nonselectable genetic changes into chromosomal loci in mouse embryo-derived stem cells. The nonselectable markers were linked to a selectable marker in both insertion- and replacement-type vectors, and the transfer of the two elements to the Hprt locus was assaye... | Genetic Vectors; Molecular Sequence Data; Restriction Mapping | 1993-04 |
182 |
|
Vardeny, Zeev Valentine | Below-gap excitation of ∏-conjugated polymer-fullerene blends: implications for bulk organic heterojunction solar cells | We used a variety of optoelectronic techniques such as broadband fs transient and cw photomodulation spectroscopies, electroabsorption, and short-circuit photocurrent in bulk heterojunctions organic solar cells for studying the photophysics in ∏-conjugated polymer-fullerene blends with below-gap... | pi-conjugated polymers; Fullerene blends; Below-gap excitations; Bulk heterojunctions; Bulk organic heterojunction solar cells; Photophysics | 2008-07 |
183 |
|
Lupton, John Mark | Monitoring surface charge movement in single elongated semiconductor nanocrystals | We demonstrate a universal correlation between the spectral linewidth and position of the excitonic transition in the spectral jitter observed from single elongated colloidal quantum dots. Breaking the symmetry of electron and hole confinement as well as of the spatial directions for surface charge ... | Surface charge movement; Spectral linewidth; Excitonic transition; Spectral jitter; Colloidal nanocrystals | 2004-10 |
184 |
|
Vardeny, Zeev Valentine | Ultrafast electronic and acoustic effects in conducting polymers | The polarized picosecond pump and probe technique with 50 fsec resolution has been used to generate and detect electronic excitations and propagation of ultrasonic phonons in thin films of oriented and unoriented polyacetylene and polythiophene. We found that the photoexcitations are instantaneou... | Ultrafast electronic effects; Ultrafast acoustic effects; Polarized picosecond pump; Pump and probe technique; Ultrasonic phonons | 1990 |
185 |
|
Miller, Joel Steven | Magnetically ordered molecule-based assemblies | The development of molecules and assemblies of molecules exhibiting technologically important bulk properties, such as magnetic ordering, is an important worldwide research focus. Organic- and molecule-based magnets have been discovered and several families have been reported with magnetic orderin... | Organic-based; Lattices; Magnets | 2006 |
186 |
|
Olivera, Baldomero M.; McIntosh, J. Michael | Novel post-translational modification involving bromination of tryptophan: identification of the residue, L-6-bromotryptophan, in peptides from Conus imperialis and Conus radiatus venom | We report a novel post-translational modification involving halogenation of tryptophan in peptides recovered from the venom of carnivorous marine cone snails (Conus). The residue, L-6-bromotryptophan, was identified in the sequence of a heptapeptide, isolated from Conus imperialis, a worm-hunting... | Conotoxins; Conus imperialis; Conus radiatus; L-6-bromotryptophan | 1997 |
187 |
|
Ehleringer, James R. ; Cerling, Thure E. | Aberrant water homeostasis detected by stable isotope analysis | While isotopes are frequently used as tracers in investigations of disease physiology (i.e., 14C labeled glucose), few studies have examined the impact that disease, and disease-related alterations in metabolism, may have on stable isotope ratios at natural abundance levels. The isotopic composition... | | 2010-07-21 |
188 |
|
Sperry, John S. | Xylem hydraulics and the soil-plant-atmosphere continuum: opportunities and unresolved issues | Received for publication July 23, 2002. Soil and xylem are similar hydraulically. An unsaturated conductivity curve for soil is called a vulnerability curve for xylem?but the underlying physical basis is the same. Thus, any transport model that treats unsaturated soil conductivity would benefit by a... | Soil?plant?atmosphere continuum; Water potential | 2003 |
189 |
|
Lupton, John Mark | Time-gated electroluminescence spectroscopy of polymer light-emitting diodes as a probe of carrier dynamics and trapping | We present time-gated electroluminescence (EL) spectroscopy of a polyfluorene-based conjugated polymer. The technique is shown to be sensitive enough to pick out impurity emission orders of magnitude weaker than the cw emission. By considering the temperature dependence of the delayed emission spect... | Time-gated electroluminescence spectroscopy; Carrier dynamics; Trapping; Delayed emission | 2002-04 |
190 |
|
Morse, Michael David | Resonant two-photon ionization spectroscopy of jet-cooled Au? | A band system of jet-cooled Au, has been located in the near infrared region of the spectrum using resonant two-photon ionization spectroscopy. The origin band is located at 13 354.15 cm-? and the system extends more than 700 cm-? further to the blue. The excited state displays a radiative lifetime... | | 1991 |
191 |
|
Capecchi, Mario R. | Hoxa1 lineage-tracing indicates a direct role for Hoxa1 in development of the inner ear, the heart and the third rhombomere | Loss of Hoxa1 function results in severe defects of the brainstem, inner ear and cranial ganglia in humans and mice as well as cardiovascular abnormalities in humans. Since Hoxa1 is expressed very transiently during an early embryonic stage, it has been difficult to determine whether Hoxa1 plays a d... | Hoxa1; Inner ear; Third rhombomere; Hindbrain; Hoxa1-IRES-Cre mouse; Embryonic development; Lineage-tracing | 2010 |
192 |
|
Gondolo, Paolo | Fluid interpretation of Cardassian expansion | A fluid interpretation of Cardassian expansion is developed. Here, the Friedmann equation takes the form H2=g(ρM) where ρM contains only matter and radiation ~no vacuum!. The function g(ρM) returns to the usual 8πM /(3mpl 2 ) during the early history of the Universe, but takes a different form... | Cardassian expansion; Friedmann equation | 2003-09 |
193 |
|
Vardeny, Zeev Valentine | Spin-dependent delayed luminescence from nongeminate pairs of polarons in ∏-conjugated polymers | We measured cw photoinduced absorption (PA) and spin- 1 2 PA- and photoluminescence detected magnetic resonance (PADMR and PLDMR, respectively) in films of two representative p-conjugated polymers; poly(phenylene-vinylene) and polythiophene. From the dependences of the polaron PA and PLDMR on the ... | pi-conjugated polymers; Nongeminate pairs; Spin-dependent delayed luminescence; Photoinduced absorption; Poly(phenylene-vinylene) | 2002-12 |
194 |
|
Williams, Clayton C.; Stringfellow, Gerald B. | Effect of substrate misorientation on ordering in Ga0.5In0.5P | Ordering produced in Gao.5Ino.5P epitaxial layers grown by OMVPE can be controlled by variations in the substrate misorientation as well as the growth temperature and the growth rate. The ordering produced at a growth temperature of 620°C and a relatively low growth rate of 0.5 /μm/hr is found to ... | Ga0.5In0.5P; Epitaxial layers; Epitaxial growth; OMVPE | 1994 |
195 |
|
Coley, Phyllis D. | Herbivory and defensive characteristics of tree species in a lowland tropical forest | Rate of herbivory and defensive characteristics of young and mature leaves were measured for saplings of 46 canopy tree species in a lowland tropical rain forest (Barro Colorado Island, Panama). Grazing rates were determined in the field for sample periods in the early wet, late wet, and dry seasons... | Fiber; Herbivory; Life history; Panama; Phenolics; Plant growth; Spatial distribution; Tannins; Temporal distribution; Treefall gaps; Tropical forest | 1983 |
196 |
|
Symko, Orest George | Spin freezing below the nearest-neighbor percolation concentration in Cd1-xMnxTe and Cd1-xMnxSe | The very-low-temperature magnetization of Cdi_xMnxTe and Cdj-xMnxSe alloys shows spinglass behavior for concentrations below the nearest-neighbor percolation limit. This is attributed to short-range exchange and dipolar interactions. New magnetic phase diagrams for both systems are presented. | Spin freezing; Cd1-xMnxTe; Cd1-xMnxSe; Very-low-temperature magnetization; Spin-glass behavior | 1986-05 |
197 |
|
Gerton, Jordan | Optimizing contrast of tip-enhanced fluorescence microscopy for imaging high-density samples | Quantum dots are imaged using tip-enhanced fluorescence microscopy. Optimization of the operation parameters leads to high-contrast images of high-density samples and a novel photon analysis improves contrast further. | | 2007-05 |
198 |
|
Sperry, John S. | Winter xylem embolism and spring recovery in Betula cordifolia, Fagus grandifolia, Abies balsamea, and Picea rubens | Xylem embolism was monitored from mid-winter to mid-summer in four co-occurring species: Betula cordifolia (Reg.) Fern., Fagus grandifolia Ehrh., Abies balsamea (L.) Mill., Picea rubens Sarg. The study site was a west-facing slope in the northern Green Mountains of Vermont, U.S.A.; Betula and conife... | Conductivity; Hydraulic; Trees | 1993 |
199 |
|
Olivera, Baldomero M. | Targeted mutagenesis by homologous recombination in D. melanogaster | We used a recently developed method to produce mutant alleles of five endogenous Drosophila genes, including the homolog of the p53 tumor suppressor. Transgenic expression of the FLP site-specific recombinase and the I-SceI endonuclease generates extrachromosomal linear DNA molecules in vivo. Thes... | | 2002 |
200 |
|
Morse, Michael David | Vibronic spectroscopy of unsaturated transition metal complexes: CrC?H, CrCh?, and NiCH? | Vibronically resolved resonant two-photon ionization and dispersed fluorescence spectra of the organometallic radicals CrC2H, CrCH3 , and NiCH3 are reported in the visible and near-infrared wavelength regions. For CrC2H, a complicated vibronic spectrum is found in the 11 100?13 300 cm-1 region, with... | | 2004 |