G. Barbero、E. Miraldi、A. Stepanescu1990-09-01Journal of Applied Physics
The size and surface effects on the nematic-isotropic phase transition of a liquid crystal are analyzed using a functional form of the surface energy proportional to the square of the scalar order parameter. The evaluated temperature shift agrees with the published experimental observations. This form seems confirmed…
Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesPhotonic Crystals and Applications
Lech Longa、Hans‐Rainer Trebin1990-09-01Physical Review A
A phenomenological theory of polar structures in chiral biaxial liquid crystals is constructed exploiting the properties of a symmetric and traceless tensor order parameter field ${\mathit{Q}}_{\mathrm{\ensuremath{\alpha}}\mathrm{\ensuremath{\beta}}}$(r) and of a polar field ${\mathit{P}}_{\mathrm{\ensuremath{\alpha}}…
Liquid Crystal Research AdvancementsNonlinear Dynamics and Pattern FormationPlant Reproductive Biology
Raj K. Gupta、R. R. Singh、Kenneth K. Tanji1990-09-01Soil Science Society of America Journal
Abstract Calcareous sodic soils having high sodicity and high pH often maintain high solution P concentration. The effect of high exchangeable Na, high pH, and alkali anions and carbonates on the release of inorganic P was investigated in soils representing the three major benchmark sodic soil series found in the Indo…
Soil Carbon and Nitrogen DynamicsSoil and Unsaturated FlowClay minerals and soil interactions
Heinz‐S. Kitzerow、P. P. Crooker、Samuel Kwok 等 5 位作者1990-09-01Physical Review A
Electric fields can cause structural changes of the blue phases (BP) that appears in chiral liquid crystals. In BP I and BP II, electrostrictive effects cause a shift of the Bragg reflection wavelengths with little intensity change. In BP III, for systems with negative dielectric anisotropy, there is a strong increase…
Liquid Crystal Research AdvancementsOptical Polarization and EllipsometryMolecular spectroscopy and chirality
Elvira D. Guevarra、Takeshi Tabuchi1990-09-01Agricultural and Biological Chemistry
Many strains of the genus Ustilago were found to be good producers of organic acids, that is, itaconic, l-itatartaric, l-2-hydroxyparaconic, and l-malic acids. Itatartaric and 2-hydroxyparaconic acids were invariably produced together with itaconic acid. From these findings and the results of the experiments with perm…
Algal biology and biofuel productionDiatoms and Algae ResearchMicrobial Metabolites in Food Biotechnology
Pantcho Stoyanov、Sohail Akhter、John White1990-09-01Surface and Interface Analysis
Abstract The interaction between in situ evaporated aluminum and plyvinyl alcohol (PVA) polymer at 300 K was studied by XPS. The aluminum condenses on the PVA surface by a Volmer–Weber (clustering) mechanism; it takes about a 3.7 monolayer deposition to nucleate clusters sufficiently large to exhibit core binding ener…
Electron and X-Ray Spectroscopy TechniquesIon-surface interactions and analysisSurface and Thin Film Phenomena
J. Suchanicz、W Ptak1990-09-01Ferroelectrics Letters Section
The existence of polar regions in Na0.5Bi0.5Tio3 and pyroelectric measurements. Both dynamics and sizes of these regions depend on temperature and time.
Ferroelectric and Piezoelectric MaterialsMultiferroics and related materialsMicrowave Dielectric Ceramics Synthesis
D. M. Szmyd、P. Porro、A. Majerfeld 等 4 位作者1990-09-01Journal of Applied Physics
A systematic study of the photoluminescence (PL) of Se-doped n-type GaAs grown by metalorganic chemical vapor deposition is reported. A new method is presented to determine the electron effective mass of n+-direct-gap semiconductors from the PL spectrum. GaAs samples with electron densities from 1015 to 8×1018 cm−3 we…
Semiconductor Quantum Structures and DevicesZnO doping and propertiesChalcogenide Semiconductor Thin Films
Michael R. Hyman、Chang‐Yub Kim、Daniel J. Arp1990-09-01Journal of Bacteriology
Carbon disulfide has long been recognized as a potent inhibitor of nitrification, and it is the likely active component in several nitrification inhibitors suitable for field use. The effects of this compound on Nitrosomonas europaea have been investigated, and the site of action has been determined. Low concentration…
Nitric Oxide and Endothelin EffectsElectrochemical sensors and biosensorsAdvanced Nanomaterials in Catalysis
E. Batawi、D.G. Morris、M.A. Morris1990-09-01Materials Science and Technology
The mechanical properties of as well as microstructural changes in rapidly solidified ternary Cu–Cr based alloys were studied for various ternary additions. The flow stresses of the binary and various ternary alloys are explained in terms of Orowan strengthening mechanisms. Zirconium, magnesium, and, to a lesser exten…
Microstructure and mechanical propertiesMetallurgy and Material FormingAdvanced materials and composites
Ellen Ivers‐Tiffée、W. Wersing、M. Schießl 等 4 位作者1990-09-01Berichte der Bunsengesellschaft für physikalische Chemie
Abstract We present a planar cell design for Solid Oxide Fuel Cells (SOFC) which combines the ceramic materials of a solid electrolyte (Y‐stabilized ZrO 2 ), cathode (LaSrMeO 3 with Me : Mn, Co and Cr), and anode (Ni‐Cermet) with a metallic interconnection material, the so‐called metallic bipolar plate. This metallic…
Electrocatalysts for Energy ConversionAdvancements in Solid Oxide Fuel CellsFuel Cells and Related Materials
Geoffrey B. Smith1990-09-01Applied Optics
The transmittance T and reflectance R of s- and p-polarized light, incident at various angles onto thin films which contain metal and voids in an oblique columnar structure, are analyzed using suitably modified thin film equations. Columnar aluminum is treated for various column angles in uniaxial and biaxial models t…
Liquid Crystal Research AdvancementsPhotonic Crystals and ApplicationsOptical Coatings and Gratings
Daniel Mandler、Allen J. Bard1990-09-01Langmuir
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHole injection and etching studies of gallium arsenide using the scanning electrochemical microscopeDaniel Mandler and Allen J. BardCite this: Langmuir 1990, 6, 9, 1489–1494Publication Date (Print):September 1, 1990Publication History Published online1 May 2002Published inis…
Semiconductor materials and interfacesElectron and X-Ray Spectroscopy TechniquesAnodic Oxide Films and Nanostructures
Béla Pukánszky、F. Tüdös1990-09-01Makromolekulare Chemie Macromolecular Symposia
Abstract The tensile properties of 16 blends prepared from 12 different polymers were investigated in the whole composition range. The composition dependence of Young's modulus has shown less, while that of the yield and ultimate properties exhibited more significant variations with miscibility. The quantitative evalu…
Polymer crystallization and propertiesElectronic Packaging and Soldering TechnologiesPolymer Nanocomposites and Properties
W. Y. Ching、Yong‐Nian Xu、B. N. Harmon 等 5 位作者1990-09-01Physical review. B, Condensed matter
The band structures of the ferromagnetic compounds FeB, ${\mathrm{Fe}}_{2}$B, and ${\mathrm{Fe}}_{3}$B were calculated using a spin-polarized version of the first-principles self-consistent orthogonalized linear-combination-of-atomic-orbitals method. Results on the band structure, density of states (DOS), and site-, o…
Magnetic properties of thin filmsRare-earth and actinide compoundsMagnetic Properties of Alloys
Kyozi Kawasaki、Akira Onuki1990-09-01Physical Review A
We propose a theoretical interpretation of observed anomalous rheological behavior of diblock copolymers quenched into microphase-separated states having locally lamellar morphology with disorder. The proposed mechanism of the anomaly is associated with the second-sound modes occurring in a locally lamellar structure…
Material Dynamics and PropertiesRheology and Fluid Dynamics StudiesBlock Copolymer Self-Assembly
G. W. Easterwood、Jerry B. Sartain1990-09-01Soil Science Society of America Journal
Abstract In many tropical soil systems, secondary minerals are coated with sesquioxides, resulting in inherently low P availability to plants due to P‐fixation mechanisms. Research was conducted to determine the influence of hydroponically grown clover ( Trifolium repens L.) residue pretreatment in reducing orthophosp…
Soil Carbon and Nitrogen DynamicsClay minerals and soil interactionsIron oxide chemistry and applications
Z. Zheng、R. E. Tressler、K. E. Spear1990-09-01Journal of The Electrochemical Society
The oxidation of single‐crystal in dry oxygen (10 −3 ‐1 atm and 1200°–1500°C) followed parabolic kinetics. The oxygen partial pressure dependence of the oxidation rate of the (0001) carbon face decreased with increasing temperature (from 0.6 at 1200°C to 0.3 at 1500°C). A kinetic model based on parallel transport of o…
Advanced ceramic materials synthesisCatalytic Processes in Materials ScienceSemiconductor materials and devices
D. L. Wood、K. Nassau1990-09-01Applied Optics
The refractive index, the temperature coefficient of the refractive index, and the optical transparency of gadolinium gallium garnet are reported as a function of wavelength from the near UV to the middle IR. The materialis transparent enough for good optical components between 0.36 and 6.0 microm, and the refractive…
Photonic and Optical DevicesPhotorefractive and Nonlinear OpticsPhase-change materials and chalcogenides
Mitsuaki Ginoza1990-09-01Molecular Physics
A simple expression for the mean-spherical-approximation (MSA) solution of the Ornstein-Zernike (OZ) equation in the Baxter formalism is presented for the case with n components and a single Yukawa term with factorizable prefactor: all coefficients of the MSA solution are given in terms of simple rational functions of…
Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesThermodynamic properties of mixtures