文献浏览

Información bibliográfica

Effects of Alloying Elements on Interface and Properties of C/Cu Composites

TABLE OF CONTENTS

Molecular Cloning and Characterization of a cDNA for the r Subunit of a G Protein from Rice

We isolated a cDNA for the rβ subunit of a heterotrimeric G protein from rice (Oryza sativa L. cv. Nipponbare). The amino acid sequence deduced from the cDNA was 76% and 94% homologus to the sequences of the rβ subunits from Arabidopsis and maize (AGrβ1 and ZGrβ1), respectively.

Effect of Surface Area on the Oxidation of Methane over SolidOxide Solution Catalyst La0.8Sr0.2MnO3

Solid oxide solutions of the type La0.8Sr0.2MnO3with BETsurface areas of 28, 20, 12, and 8 m2/g were prepared bysintering at 700, 800, 900, and 1000°C, respectively. Thecatalysts were tested for methane total oxidation in a fixed bedreactor with feed containing 0.28% CH4, 12% O2,and the balance helium. The activity of…

Electro-optic properties of a polymer-dispersed liquid-crystal film: Temperature dependence and phase behavior

Electro-optic measurements and optical microscopy were used in an investigation into the microscopic properties that determine the switching characteristics of a polymer-dispersed liquid-crystal (PDLC) film. A simple test is demonstrated that provides a necessary condition for the applicability of a previously publish…

Chemical shifts and optical properties of tin oxide films grown by a reactive ion assisted deposition

Highly oriented nonstoichiometric tin oxide thin films were grown by a reactive ion assisted deposition onto Si(100) and glass substrates at room temperature as a function of relative ion (O)/atom (Sn metal) arrival ratio, and concurrently the deposited ion energy per atom (eV/atom) were changed from 10 to 100 eV/atom…

Deformation of Interparticle Necks by Diffusion‐Controlled Creep

The deformation of a neck between two spherical particles of the same size by coupled grain‐boundary and surface diffusion has been simulated numerically through the finite‐difference method. In the case of pure sintering where there is no applied stress, the results agree quite well with simple analytical models. Whe…

LPCVD against PECVD for micromechanical applications

After discussion of the basic aspects of CVD and its reaction kinetics LPCVD and PECVD will evolve as techniques commonly used at high temperature and lower temperature , respectively. Films deposited by these two techniques differ in several aspects, i.e., thickness, uniformity, purity, density, electrical properties…

Comparison of LiV3 O 8 Cathode Materials Prepared by Different Methods

Lithium trivanadate, LiV 3 O 8 , can be prepared in a finely dispersed form by dehydration of aqueous lithium vanadate gels. Two methods of dehydration, both easily adaptable to large‐scale production, are described in this work: freeze drying and spray drying. After heat‐treatment of the dried gels (xerogels) to remo…

Circle, sphere, and drop packings

We studied the geometrical and topological rules underlying the dispositions and the size distribution of nonoverlapping, polydisperse circle packings. We found that the size distribution of circles of radii R that densely cover a plane follows the power law N(R)\ensuremath{\propto}${\mathit{R}}^{\mathrm{\ensuremath{-…

First-principles investigation of 180° domain walls in BaTiO3

We present a first-principles study of 180\ifmmode^\circ\else\textdegree\fi{} ferroelectric domain walls in tetragonal barium titanate. The theory is based on an effective Hamiltonian that has previously been determined from first-principles ultrasoft-pseudopotential calculations. Statistical properties are investigat…

Dislocation-mediated melting near isostructural critical points

We study the interplay between an isostructural critical point and dislocation-mediated two-dimensional melting, using a combination of Landau and continuum elasticity theory. If dislocations are excluded, coupling to the elastic degrees of freedom leads to mean-field critical exponents. When dislocations are allowed,…

Polypyrrole Composite Electrodes in an All‐Polymer Battery System

We have fabricated an all‐polymer battery utilizing the redox properties of electrically conducting polymers for the anode and cathode in conjunction with an ionic conducting polymer gel electrolyte. The anode and cathode consist of pyrrole electropolymerized onto a graphite fiber substrate resulting in a high‐surface…

Microbial Synthesis and Properties of Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

Microbial synthesis of copolymers of [R]-3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB), P(3HB-co-4HB), by Alcaligenes eutrophus, Alcaligenes latus, and Comamonas acidovorans from various carbon sources has been studied. The copolyester compositions varied from 0 to 100 mol% 4HB, depending on the microorganism an…

Coarse-grained description of thermo-capillary flow

A mesoscopic or coarse-grained approach is presented to study thermo-capillary induced flows. An order parameter representation of a two-phase binary fluid is used in which the interfacial region separating the phases naturally occupies a transition zone of small width. The order parameter satisfies the Cahn–Hilliard…

Polysaccharides of Intracrystalline Glycoproteins Modulate Calcite Crystal Growth In Vitro

Abstract Assemblies of glycoproteins from within the mineralized tissues of sea urchins and mollusks both interact in vitro in a similar manner with growing calcite crystals. A protein‐rich fraction, a polysaccharide‐rich fraction, and a fraction composed of densely glycosylated peptide cores were obtained by chemical…

A Monte Carlo modeling of electron interaction with solids including cascade secondary electron production

Abstract A new Monte Carlo simulation approach has been developed to describe electron scattering and secondary electron generation processes in solids. This approach is based on the uses of Mott's elastic scattering cross section and Penn's dielectric function. A very good agreement has been found on the energy distr…

Collagen-based devices for soft tissue repair

The intrinsic biological and physiochemical characteristics of collagen have been exploited to prepare a variety of commercially available medical products spanning many medical specialties. The properties of purified collagen can be modified to obtain forms which comply to specific applications. In particular, collag…

Electrolyte Optimization for Cathodic Growth of Zinc Oxide Films

Zinc oxide films of good quality have been cathodically deposited on NESA glasses from aqueous 0.03 to 0.1 mol/liter zinc nitrate electrolyte at 335 K.The films had a wurtzite structure and an optical bandgap energy of 3.3 eV which is characteristic of ZnO.