UScholar Works
 
Filters: Date: "1989" School Or College: "College of Science" Collection: "ir_uspace"
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CreatorTitleDescriptionSubjectDate
1 Ailion, David Charles79Br nuclear-quadrupole-resonance lineshape and Raman-induced spin-lattice relaxation in the incommensurate phase of β- ThBr4We performed 7 9Br nuclear-quadrupole-resonance (NQR) line-shape and spin-lattice relaxation time measurements in the incommensurate (D system j8-ThBr4 over the temperature range 293-2.5 K. In addition, we extended the theory of the effects of Raman processes on amplitudon and phason spin-lattice re...Spin-lattice; NQR; Raman process; Line shape; Phason gap; Incommensurate systems1989
2 Symko, Orest GeorgeAbsorption at radio frequencies in superconducting Y1Ba2Cu3OyThe large magnetic-field-dependent ac absorption in superconducting Y1Ba2Cu3Oy ceramics and powders decreases slowly with increasing frequency in the range 2-16 MHz. The magnetic-field-dependent ac absorption is observed below Tc in superconducting Y1Ba2Cu3Oy ceramics, powders and twinned crystals ...Copper-octahedral oxygen perovskites; Superconducting Y1Ba 2Cu3Oy; ac absorption1989
3 Beckerle, Mary C.Activation-dependent redistribution of the adhesion plaque protein, talin, in intact human plateletsTalin is a high molecular weight protein localized at adhesion plaques in fibroblasts. It binds vinculin and integrin and appears to participate in generating a transmembrane connection between the extracellular matrix and the cytoskeleton.Talin1989
4 Lee, Hyo JongAutomatic mesh analysis technique by knowledge-based systemThe finite element analysis technique has been recognized as a very important tool to solve various engineering problems, such as structural analysis, heat transfer, and fluid dynamics. The key point to the technique is discretization of the domain of interest into many finite elements. A good resul...Mesh analysis; Mesh generation algorithm1989
5 Carter, Tony M.Cascade: hardware for high/variable precision arithmeticThe Cascade hardware architecture for high/variable precision arithmetic is described. It uses a radix-16 redundant signed-digit number representation and directly supports single or multiple precision addition, subtraction, multiplication, division, extraction of the square root and computation...1989
6 Carter, Tony M.; Smith, Kent F.Cell matrix methodologies for integrated circuit designA class of integrated circuit design and implementation methodologies is described. These techniques are unique in that they simultaneously model both function and interconnect using cells. These cells are designed such that cell adjacency normally implies interconnection. The absence of an interco...Integrated circuit design; Cell matrix1989
7 Armentrout, Peter B.Collision-induced dissociation of Fen+ (n=2-10) with Xe: ionic and neutral iron binding energiesCross sections for collision-induced dissociation (CID) of Fen+ with Xe, 2≤n≤10, are presented. Experiments were performed on a newly constructed guided ion beam mass spectrometer, the design and capabilities of which are described in detail. The single mechanism for dissociation of iron cluster...1989
8 Potts, Wayne K.Consequences of self and foreign superantigen interaction with specific VB elements of the murine TCR aBThe aB T-cell receptor (TCRaB) recognizes a ligand composed of an antigen fragment complexed with a product of the major histocompatibility complex (MHC). The repertoire of receptors is limited both by the germ line of receptor variable elements and by selective events that take place during T-cell ...Toxins; Repertoire; Expression1989
9 Golden, Kenneth M.Convexity in random resistor networksThe bulk conductivity o*(p) of the bond lattice in Zd is considered, where the conductivity of the bonds is either 1 with probability p or e > 0 with probability 1 - p. Rigorous and non-rigorous results demonstrating convexity of o*(p) near the percolation threshold pc are presented.Conductivity; Bond lattice; Critical exponent t1989
10 Bohs, Lynn A.Ethnobotany of the genus Cyphomandra (Solanaceae)Plants of the genus Cyphomandra (Solanaceae) have long been utilized for their edible fruits in their native Latin America. The best-known species is the domesticated tree tomato or tamarillo, Cyphomandra betacea. This species, popular as a raw or cooked fruit, is widely cultivated in Andean South ...Cyphomandra; Cyphomandra betacea; Alkaloids1989
11 Lee, Hyo JongImplementation and characteristics of rule-based system for the finite element analysisIt it well known that the analysis of process for the finite element method is tedious and errorprone steps. Considering the importance of the task of engineering analyses, such as structural analysis, heat transfer, fluid flow simulation, and electromagnetic potential, many researchers have tried t...finite element analysis; Rule-based system1989
12 Morse, Michael DavidLaser excitation spectroscopy of the A and B states of jet-cooled copper dimer: evidence for large electronic isotope shiftsFluorescence excitation spectra recorded for the A-X system of jet-cooled Cu2 show conclusive evidence of a ?? = 0 transition, and the A state is thereby definitively assigned as ??u+. A previous assignment of the B state as ??u+ is confirmed, but the vibrational levels of this state are complicated...1989
13 Williams, Clayton C.Lateral dopant profiling with 200 nm resolution by scanning capacitance microscopyMeasurement of dopant density in silicon with lateral resolution on the 200 nm scale has been demonstrated with a near-field capacitance technique. The technique is based upon the measurement of local capacitance between a 100 nm tip and a semiconducting surface. Lateral dopant imaging is achieved b...Dopant profile; Doping density; Scanning capacitance microscopy1989
14 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
15 Miller, Joel Steven; Epstein, Arthur J.Optical properties of quinolinium tetracyanoquinodimethanide, [Qn(TCNQ)2] and (N-methylphenazinium)x(phenazine)1-x (tetracyanoquinodimethane) [(NMP)x(Phen)1-x(TCNQ)]We present here optical-absorption data of quinolinium ditetracyanoquinodimethanide [Qn(TCNQ)2] and (N-methylphenazinium)x(phenazine)1-x(tetracyanoquinodimethanide) [(NMP)x(Phen)1-x(TCNQ)] for 0.5 <_x<_ 0.6. These materials span the range of electronic structure from commensurate, to commensurate ...Commensurate; Lattice; Electron1989
16 Armentrout, Peter B.Oxidation reactions at variably sized transition metal centers: Fen+ and Nbn+ + O2 (N=1-3)Cross sections for the reactions of Fen+ and Nbn+ (n = 1-3) with 02 are measured as a function of kinetic energy over a range of 0 to > 10 eV. In all systems, analysis yields insight into the kinetics and thermochemistry of the oxidation processes. Nbn+ reaction with 02 exothermically near the Lange...Metal clusters; Nobium ions; Iron ions; Exothermic reactions1989
17 Armentrout, Peter B.Reactions of Ar+, Ne+, and He+ with SiF4 from thermal energy to 50 eV c.m.Guided ion-beam techniques are used to measure the cross sections for reaction of SiF4 with Ar+, Ne+, and He+ from thermal to 50 eV. Charge transfer followed by loss of F atoms are the sole processes observed. All SiFx + (x = 0-4) products are observed, except for SiF4 + from reaction with Ne+ and ...Ion-molecule reactions; Tetrafluorosilane; Rare gas ions; Endothermic reactions; Plasma systems1989
18 Coley, Phyllis D.Red coloration of tropical young leaves: a possible antifungal defense?Many woody species in humid tropical forests synchronously flush entire canopies of young red leaves. Numerous unsuccessful attempts have been made to explain the adaptive value of this visually striking phenomenon. In the humid tropics, fungal attack is a potentially important source of mortality f...Herbivory; Anthocyanin; Antifungal defense; Atta columbica; Panama; Leaf-cutting ants; Tropics; Young leaves1989
19 Morse, Michael DavidResonant two-photon ionization spectroscopy of jet-cooled NiPtResonant two-photon ionization spectroscopy of jet-cooled NiPt has been used to investigate the possibility of <f-electron contributions to the bonding in this species. Based on an abrupt onset of predissociation, the bond strength of NiPt is assigned as D0 (NiPt) = 2.798 ? 0.003 eV. Comparisons of ...1989
20 Williams, Clayton C.Scanning capacitance microscopy on a 25 nm scaleA near-field capacitance microscope has been demonstrated on a 25 nm scale. A resonant circuit provides the means for sensing the capacitance variations between a sub-lGO-nra tip and surface with a sensitivity of 1X 10 19 F in a I kHz bandwidth. Feedback control is used to scan the tip at constant g...Scanning capacitance microscopy1989
21 Bohs, Lynn A.Solanum allophyllum (Miers) Standl. and the generic delimitation of Cyphomandra and Solanum (Solanaceae)Solanum allophyllum has previously been placed in Cyphomandra and in Solarium. This species has a number of morphological features not found in Cyphomandra, but has been included in the genus because it has a similar growth habit, three-leaved sympodial units with inflorescences in branch forks, and...Solanum allophyllum; Cyphomandra1989
22 Miller, Joel Steven; Epstein, Arthur J.Specific heat of decamethylferrocenium tetracyanoethanide (DMeFc)(TCNE)We report the specific heat C(T) of (DMeFc)(TCNE) for temperatures 3 K < T < 50 K. We observe an anomaly at Tc-4.82 K corresponding to a transition to a three-dimensional (3D) macroscopic ferromagnet. A broad maximum at = 15 K corresponds to an exchange interaction of J = 35 K along the chain axis. ...Temperature; Ferromagnetic; Magnetic1989
23 Morse, Michael DavidSpectroscopy and electronic structure of jet-cooled GaAsAn optical spectrum, obtained by resonant two-photon ionization spectroscopy, is reported for jet-cooled diatomic gallium arsenide. The ground state is identified as X??-, deriving from a ??rr? molecular configuration, and is characterized by ?" = 215 cm-1, ?"exe" = 3 cm-1, and r0' = 2.53 ? 0.02 ?. ...1989
24 Armentrout, Peter B.Spin-orbit state-selected reactions of Xe+(2P3/2 and 2P1/2) with H2, D2, and HDSpin-orbit state-selected reactions of X e + (2Pj ), j = 3/2 and 1/2, with isotopic molecular hydrogen (H2 , D2 , and HD) to form X e H + and XeD + are studied using guided ion beam mass spectrometry. Reaction cross sections are determined as a function of reactant kinetic energy from near thermal ...Spin-orbit; Xenon ions; Hydrogen isotopes; Isotope effects; Ion-molecule reactions1989
25 Miller, Joel StevenStructural and magnetic characterization of a- and B-2,4-hexadiyne-1,6-diyl Bis(2,2,5,5-tetramethyl-1-oxyl-3-pyrroline-3-carboxylate) and its thermal degradation productThe search for ferromagnetic organic compounds and polymers is the focus of contemporary research.1 - 5 Polymerization of di-iminoxyl diacetylene monomers has been suggested as a means to prepare a high spin potentially ferromagnetically coupled polymers3 and the thermal, photochemical, and glow di...Ferromagnetic; Magnetization; Polymers1989
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