Materials Literature
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We report the design and performance of 300-mK composite bolometers that use micromesh absorbers and support structures patterned from thin films of low-stress silicon nitride. The small geometrical filling factor of the micromesh absorber provides 20x reduction in heat capacity and cosmic ray cross section relative t…
The relationship between surface sediment diatom (Division: Bacillariophyta) assemblages and measured water chemical and environmental variables in 30 lakes from northern Fennoscandia were examined...
Hybrid molecular electrodes , based on a conducting polymer matrix containing a dispersion of an electroactive inorganic component, are reported. The phosphomolydate anion, [PMo 12 O 40 ] 3⊖ , is dispersed in polypyrrole to investigate cooperative phenomena between the components. The interactions are shown to influen…
Modulation of light by light as stimulus has been explored by the use of liquid-crystalline (LC) materials with photosensitive moieties. Azobenzene derivatives with monomeric and polymeric forms were prepared, which show nematic (N) LC behavior in the trans form and no LC phase in the cis isomer. Photoirradiation of a…
Phase transitions in crystalline substances are a major field of study in high-pressure physics. The sequences of structural transformations and the boundaries separating different phases have been established for a majority of elements under high pressure and for different temperatures. Though both electron and struc…
The design of supramolecular templates to direct the synthesis of organized inorganic materials is illustrated for aragonite (CaCo 3 ), which is metastable under ambient conditions but found in gallstones, fish otoliths, etc. Spreading of the template 5‐hexadecyloxyisophthalic acid at the air/water interface is shown…
We present here a microscopic and self-consistent calculation of the self-diffusion coefficient of a small tagged particle in a dense liquid of much larger particles. In this calculation the solute motion is coupled to both the collective density fluctuation and the transverse current mode of the liquid. The theoretic…
The ab initio crystal structure solution of a layer silicate is presented. Since the crystallinity of the material is limited, the corresponding X-ray powder pattern shows only moderate resolution. Based on a new interpretation of the tangent formula, a general direct method strategy for the determination of the cryst…
The combination of intense X-ray synchrotron radiation and an imaging-plate area detector makes it possible to extract real-time structural information using Rietveld refinement of individual time slices. Powder diffraction data from capillary samples were collected using a flat imaging plate mounted perpendicular to,…
X-ray analyses of wild-type and mutant flavodoxins from Clostridium beijerinckii show that the conformation of the peptide Gly57-Asp58, in a bend near the isoalloxazine ring of FMN, is correlated with the oxidation state of the FMN prosthetic group. The Gly-Asp peptide may adopt any of three conformations: trans O-up,…
Abstract Five species of unicellular green algae were exposed to a broad range of Cu2+ and Zn2+ concentrations to examine the relationship between the free Cu2+ and Zn2+ ion concentrations and algal growth at metal concentrations relevant for freshwater phytoplankton. We estimated extra- and intracellular metal concen…
Oxides on ternary magnesium alloys MgAlZn and MgAlRE were investigated by transmission electron microscopy using ultramicrotomed film sections. These films have a three‐layered structure, similar to pure Mg and binary MgAl allows characterized by a hydrated inner layer, a thin and dense intermediate region, and a plat…
Abstract Based on the experimental data presented in Part I, two uniaxial constitutive models are constructed. The first, a nonlinear viscoelastic (NVE) model, is formulated using the mechanical analogy consisting of one independent spring and six Kelvin elements in series. Creep data are used to determine the model p…
The direct catalytic conversion of alkanes into aromatics has found potentially important industrial applications. Initially only alkanes with 6 and more carbon atoms in the chain were concerned. Supported platinum catalysts were found active for the aromatization of alkanes; the drawbacks of these catalysts were thei…
Multilayer ultrathin films composed of titanium dioxide nanosized particles and ionic polystyrene molecules have been fabricated on single-crystal silicon, quartz, and glass substrates by a novel molecular self-assembly process. X-ray photoelectron spectroscopy (XPS) indicates that the formed cationic TiO 2 particles…
Atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and near-field scanning optical microscopy (NSOM) have been used to characterize the nanostructure of Au colloid-based surfaces. Because these substrates are composed of particles whose dimensio…
The molecular structure of alanine racemase from Bacillus stearothermophilus was determined by X-ray crystallography to a resolution of 1.9 A. The alanine racemase monomer is composed of two domains, an eight-stranded alpha/beta barrel at the N-terminus, which includes residues 1-240, and a C-terminal domain essential…
In this paper we show that the use of colloidal assemblies as templates favors the control of the shape of nanoparticles. Cylindrical copper metallic particles having same size can be obtained in various parts of the phase diagram when the template is made of interconnected cylinders. A very low amount of cylinders (1…
We have been exploring the optical properties of nanoscopic gold particles prepared by electrochemically depositing Au within the pores of nanoporous alumina membranes. Maxwell−Garnet (MG) effective medium theory has been used as a guide for modeling the optical properties of these Au nanoparticle/alumina membrane com…
Three compounds were obtained from the reactions of Co(NCS) 2 with pyrazine and 4,4‘-bipyridine in different solvents: Co(NCS) 2 (pyz) 2 ( 1 ) has a 2D sheet structure, monoclinic, C 2/ m, a = 10.039(2) Å, b = 10.382(2) Å, c = 7.190(1) Å, β = 118.64(1)°, Z = 2; Co(NCS) 2 (H 2 O) 2 (4,4‘-bipy)·4,4‘-bipy ( 2 ) has linea…