Materials Literature
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Expression of Escherichia coli open reading frame yfcX is shown to be required for medium-chain-length polyhydroxyalkanoate (PHA(MCL)) formation from fatty acids in an E. coli fadB mutant. The open reading frame encodes a protein, YfcX, with significant similarity to the large subunit of multifunctional beta-oxidation…
Summary The morphology and distribution of six benthic colonial diatoms were investigated from the perspective of fractal geometry and stream ecology to test whether colonial complexity of benthic diatoms is associated with a tolerance to environmental variability, that is, if a random force, such as the unpredictabil…
The Azotobacter vinelandii phbBAC genes encode the enzymes for poly-beta-hydroxybutyrate (PHB) synthesis. The phbR gene, which is located upstream of and in the opposite direction of phbBAC, encodes PhbR, a transcriptional activator which is a member of the AraC family of activators. Here we report that a mutation in…
We have considered theoretically the main properties of layered periodical structures [one-dimensional photonic band gap (PBG) structures] that include layers of so-called backward-wave material (BW), whose both permittivity and permeability are negative. Each period consists of one layer of a usual material and one l…
Using theoretical models, we undertake the first investigation into the rich behavior that emerges when binary particle mixtures are blended with microphase-separating copolymers. We isolate an example of coupled self-assembly in such materials, where the system undergoes a nanoscale ordering of the particles along wi…
Abstract Fluorohectorites were rendered organophilic through the cation exchange of sodium intergallery cations for protonated monoamine, diamine, and triamine oligopropyleneoxides and octadecylamine, benzylamine, and adducts of octadecylamine and benzylamine with diglycidyl ether of bisphenol A (DGEBA). The influence…
Single element quasicrystalline monolayers were prepared by deposition of antimony and bismuth on the fivefold surface of icosahedral ${\mathrm{A}\mathrm{l}}_{71.5}{\mathrm{P}\mathrm{d}}_{21}{\mathrm{M}\mathrm{n}}_{8.5}$ and the tenfold surface of decagonal ${\mathrm{A}\mathrm{l}}_{71.8}{\mathrm{N}\mathrm{i}}_{14.8}{\…
We show the existence of three well defined time scales in the dynamics of wormlike micelles after a step between two shear rates on the stress plateau. These time scales are compatible with the presence of a structured interface between bands of different viscosities and correspond to the isotropic band destabilizati…
We explore the possibility of extracting information about lattice dynamics in simple crystal structures from the neutron pair-density function (PDF) through inverse data analysis. Contrary to the claims by Dimitrov, Louca, and Roeder [Phys.Rev. B 60, 6204 (1999)], and in agreement with recent work by Reichardt and Pi…
Many structural transformations involve a group-nonsubgroup relationship between the initial and transformed phases, and hence are beyond the purview of conventional Landau theory. We utilize a systematic and robust methodology to describe such reconstructive martensitic transformations by coupling group-theoretical a…
In this work we analyze the room-temperature linewidth for several Raman features (i.e., the radial breathing mode, the G band, the D band, and the ${G}^{\ensuremath{'}}$ band) observed for individual isolated single-wall carbon nanotubes (SWNTs). Temperature-dependent measurements on SWNT bundles and isolated SWNTs s…
Indium gadolinium digermanium heptaoxide, In(1.08)Gd(0.92)Ge(2)O(7), with a thortveitite-type structure, has been prepared as a polycrystalline powder material by a high-temperature solid-state reaction. As in the mineral thortveitite, the crystal structure belongs to the monoclinic system, with space group C2/m (No.…
The aqueous synthesis and electrochemical properties of the new nanocrystalline material M 1 - x V 3 O 8 - y F z · n H 2 O (M = NH 4, K; x ≈ 0.0−0.2; y ≈ 0.0−0.2; z ≈ 0.1−0.2; n ≈ 1) are described. This material is easily prepared by precipitation from aqueous HF-acidified ammonium or potassium vanadate solutions. M 1…
The synthesis of silicon nanowires containing erbium in a discrete layered structure has been achieved. These wires are prepared by the pyrolysis of silane and a volatile erbium complex on a gold catalyst surface, with the relative size of the wire and sample crystallinity affected by the timing in which erbium is int…
One efficient strategy for creating nanostructures on surfaces is to use the catalytic properties of a surface molecule. This strategy benefits from the amplification and chemical specificity inherent in catalysis. We describe a demonstration of the key step of such a strategy: the surface trapping of a product genera…
Novel lamellar mesophases which are quite distinct from conventional smectic mesophases were obtained with a bolaamphiphilic triblock molecule composed of a rigid biphenyl core, two polar 2,3-dihydroxypropoxy groups in the terminal 4- and 4'-positions, and a semiperfluorinated chain [O(CH2)6C10F21] in the lateral 3-po…
Isolated vertically aligned carbon nanofibers (VACNFs) have been grown using dc plasma-enhanced chemical vapor deposition, and the effects of the growth conditions on VACNF morphology and composition have been determined in substantial detail. The dependence of the growth rate, tip and base diameters, and chemical com…
The structural changes occurring during heating in a syndiotactic polystyrene (sPS)−solvent complex were monitored in situ by X-ray diffraction. The room temperature δ form transformed into the γ form on heating above the glass transition temperature of the sPS. The transition temperature showed a linear dependency on…
Strong intermolecular hydrogen bonding is capable of suppressing concentration fluctuations and coupling segmental relaxations in polymer blends whose components exhibit a large difference in their respective T g 's (Δ T g ). In this paper we report on our dielectric study of blends of poly(4-vinylphenol) [PVPh] with…
Uniform spherical aggregates of palladium nanoparticles with a mean diameter of 70 nm were produced by stirring of palladium(II) acetate with octa(3-aminopropyl)octasilsesquioxane octahydrochloride ( 1 ) as a cubic-linker in methanol at room temperature via self-organized spherical templates of palladium ions and 1 .…