UScholar Works
 
Filters: Date: "1985" School Or College: "College of Science" Collection: "ir_uspace"
1 - 25 of 15
Number of results to display per page
CreatorTitleDescriptionSubjectDate
1 Ailion, David Charles; Morris, Alan H.Asymmetric spin echo sequences. a simple new method for obtaining NMR 1H spectral imagesThe nuclear magnetic resonance (NMR) signal decay produced by reversible tissue-induced dephasing of the magnetization components in the transverse plane (reversible tissue-induced dephasing) was measured and expressed as a function of a new transverse relaxation time T'2 (T2 prime) for samples of ...Asymmetric spin echo; Signal decay; Chemical shift; Tissue characterization; Lung aeration; Fatty liver1985
2 Ailion, David CharlesCommensurability and defect-induced phason gaps in incommensurate systemsThe phason energy gap has been observed to increase on going from the incommensurate to higher-order commensurate phases in the "devil's staircase" compound [N(CH3)4]2ZnCl4. The gap was determined via the phason-induced 1 4N spin-lattice relaxation contribution, which was obtained from the variati...Phasons; Commensurate; Incommensurate; Lattices; Modulation1985
3 Olivera, Baldomero M.; Gray, William Robert; Yoshikami, DojuConus geographus toxins that discriminate between neuronal and muscle sodium channelsWe describe the properties of a family of 22-amino acid peptides, the μ-conotoxins, which are useful probes for investigating voltage-dependent sodium channels of excitable tissues. The μ-conotoxins are present in the venom of the piscivorous marine snail, Conus geographus L. We have purified even...Conus geographus; Venom; Conotoxins; Sodium channels; Neurotoxins1985
4 Vardeny, Zeev ValentineEffect of bias illumination on photoinduced absorption decay in ?-Si:HZeldov and Weiser1 proposed a model to explain the influence of optical biasing on the decay of photoinduced absorption (PA) in ?-Si:H at high temperatures observed by Pfost, Vardeny, and Tauc.2 This model differs from the model originally used2 for interpreting the experimental data at temperatures...Optical biasing; Bias illumination; Photoinduced absorption decay; a-Si:H; Amorphous silicon1985
5 Davidson, Diane W.Experimental study of diffuse competition in harvester antsExperiments carried out over a 5-yr period in the Chihuahuan Desert support the a priori prediction of diffuse competition between two species of harvester ants. Despite dietary overlap between a large species {Pogonomyrmex rugosus) and a small species (Pheidole xerophila), the large species facilit...Chihuahuan Desert; Ants; Facilitation; Resource allocation; Granivory1985
6 Davidson, Diane W.Granivory in the Chihuahuan Desert: interactions within and between trophic levelsWe investigated the effects of Chihuahuan Desert granivores on three seasonal classes of plant resource species, the effects of these resource classes on one another, and the ways in which interactions through plant resources affect the abundances of seed consumers. At our study site, three seasona...Annual plant; Ant; Competition; Community; Desert; Ecosystem structure; Experiment; Granivore; Indirect interaction; Rodent; Population cycles; Seed predation1985
7 Davidson, Diane W.Granivory in the Chihuahuan desert: interactions within and between trophic levelsWe investigated the effects of Chihuahuan Desert granivores on three seasonal classes of plant resource species, the effects of these resource classes on one another, and the ways in which interactions through plant resources affect the abundances of seed consumers. At our study site, three seasona...Annual plant; Ant; Competition; Community; Desert; Ecosystem structure; Experiment; Granivore; Indirect interaction; Rodent; Population cycles; Seed predation1985
8 Williams, Clayton C.High-resolution photothermal laser probeAn 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 probes1985
9 Seger, JonIntraspecific resource competition as a cause of sympatric speciation[In most models of speciation], the fitness value of an animal is determined by the genotype it has, and the habitat in which it lives. In a more realistic model it should also depend on how much necessary resource is available for the animal and the competition from other genotypes for this resourc...Phenotype; Models; Species1985
10 Ailion, David CharlesNMR spectra and relaxation in incommensurate systems in the presence of a devil's staircaseThe possibility of discriminating true incommensurate phases from long period commensurate phases via NMR lineshape and spin-lattice relaxation measurements is discussed. The theoretical results are compared with experimental data in Rb2ZnCl4, Rb2ZnBr4, and [N(CH3)4]2ZnCl4. Devil's staircase effects...Incommensurate phases; Commensurate phases; Phason gap; Spin-lattice relaxation1985
11 Clayton, Dale H.Nocturnal foraging of yellow-crowned night herons in the BahamasDetailed observations of nocturnal foraging of the Yellow-crowned Night Heron (Nycticorax violacevs) are not to be found in the literature, though this species commonly feeds at night (Kushlan 1978, Riegner 1982a). I observed several Yellow-crowned Night Herons foraging during November and December...Nocturnal foraging; Bahamas; Nycticorax violacevs1985
12 Miller, Joel Steven; Epstein, Arthur J.Noise-power studies of the nearly commensurate quasi-one-dimensional conductor (N-methylphenazinium)x(phenazine)1-x(7,7,8,8-tetracyano-p-quinodimethane) [(NMP)x(Phen)1-x(TCNQ)We report the noise power of (NMP)x(Phen)1-x(TCNQ) as a function of temperature (100 <_ T <_ 300 K), frequency (1<_f<_10(4) Hz), electric field (0 <_E<_300 V/cm), and conduction-electron density (0.49<_x<_0.59). The results for the commensurate, doped commensurate, and incommensurate regimes are sim...Fluctuations; Solitons1985
13 Symko, Orest GeorgeSpin glass behavior of Cd1-xMnxTe below the nearest-neighbor percolation limitMagnetization measurements down to 10 mK of Cd, _ x Mn, Te for Mn concentrations 0.01<x<0.15 show spin glass behavior. Such behavior is attributed to short-range exchange and dipolar interactions. Both interactions are used to explain the concentration dependence of the spin freezing temperatures fo...Spin glass behavior; Cd1-xMnxTe1985
14 Armentrout, Peter B.Translational energy dependence of Ar+ + XY → ArX+ + Y (XY = H2, D2, HD) from thermal to 30 eV c.m.Cross sections for the reactions of Ar+ with H2, D2, and HD to form ArH + and ArD + are measured using a new guided ion beam tandem mass spectrometer which affords an experimental energy range from 0.05 to 500 eV laboratory. The apparatus and experimental techniques are described in detail. Cross se...Translational energy; Ion-molecule reactions; Ion energy; Argon; Hydrogen; Endothermic reactions1985
15 Mattis, Daniel C.Tricritical point in random-field Ising modelThe numerical investigation of the random-field Ising model by Houghton, Khurana, and Seco1 has revealed a number of interesting features concerning the three-dimensional Ising model in a random external field Bt. Earlier, Aharony2 had already found that even in a mean-field approximation the b...Random external field; Tricritical points; Gaussian distribution1985
1 - 25 of 15