Materials Literature
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Nitroxide radicals play a central role in the recent development of organomagnetic materials or molecular-based magnetic materials. This feature article considers the recent progress in the development of molecular-based magnetic materials dealing mainly with nitroxide radical crystals and charge transfer (CT) complex…
We apply boundary integrals to the analysis of diffraction from both conductive and dielectric diffractive optical elements. Boundary integral analysis uses the integral form of the wave equation to describe the induced surface distributions over the boundary of a diffractive element. The surface distributions are use…
We describe and explore a new general transmission line model that describes the viscoelastic characteristics of thin films in terms of their shear moduli. The model contains within it the commonly used lumped-elementmodel as a limiting case, and we delineate the conditions under which thesimpler lumped-element model…
ABSTRACT Interest in biodegradable materials for packaging and agricultural uses has grown in recent years. Plant proteins have been proposed as inexpensive, renewable, and abundant feedstock. Corn zein was investigated based on value‐added considerations and on the unique thermoplastic and hydrophobic properties of z…
It has been shown that for dead marine diatom cells or diatom cells which are severely stressed metabolically, larger cells sink faster than small cells as dictated by Stokes' Law. In these cases, the slope of the sinking rate versus cell volume relationship within a culture reaches a maximum. Within cultures of rapid…
The gelation of organic solvents by low molecular weight gelators is an area of study still in its infancy. Difficulties in the design of universal gelators suitable for a wise variety of liquids arise because the self‐aggregation of teh molecules strongly depends on the polarity of the solvent. The bolaform amides pr…
The structure of concanavalin A, a saccharide-binding metalloprotein of subunit molecular weight 25000 Da§, is reported with precision and accuracy equivalent to those of small-molecule crystal structures. An X-ray data-to-parameter ratio of 6.1:1 has allowed the first unrestrained anisotropic refinement of a protein…
A local nonequilibrium approach to rapid solidification of undercooled alloys is presented. Taking into account the finite speed of mass signals, a steady-state solution to the nonisothermal rapid solidification problem has been obtained. We have found that, if the solidification front moves at a velocity V equal to o…
The three-dimensional structure of the 29-residue designed coiled coil having the amino acid sequence acetyl-E VEALEKK VAALESK VQALEKK VEALEHG-amide has been determined and refined to a crystallographic R-factor of 21.4% for all data from 10-A to 2.1-A resolution. This molecule is called coil-VaLd because it contains…
Titanium oxide and platinum have been intercalated into H 2 Ti 4 O 9 and H 4 Nb 6 O 17 by the successive reactions of H 2 Ti 4 O 9 and H 4 Nb 6 O 17 with [Pt(NH 3 ) 4 ]Cl 2 , n-C 3 H 7 NH 2 and acidic TiO 2 colloid solutions followed by UV light irradiation. The thicknesses of titanium oxide and platinum were less tha…
Abstract Members of the genera Rhodococcus and Nocardia corallina were investigated for their capability to accumulate storage lipids that occur in the cytoplasm during cultivation of the cells under nitrogen‐limiting conditions in the absence or presence of various effectors. All bacteria were able to accumulate tria…
To test the approach of combining both ionic and hydrogen-bonding interactions for the design of non-linear optical (NLO) materials, a number of phenol–pyridine co-crystals have been synthesized and their NLO properties investigated. The co-crystals are characterized by second harmonic generation measurements as well…
Fine (}0.1μm) β‐SiC powders, with 3.3 wt% large (}0.44μm) α‐SiC or β‐SiC particles (seeds) added, were hot‐pressed at 1750°C and then annealed at 1850°C to enhance grain growth. Microstructural development during annealing was investigated using image analysis. The introduction of larger seeds into β‐SiC accelerated t…
Transparent zinc oxide (ZnO) films had been chemically deposited on nonconductive glass from aqueous solutions containing zinc nitrate and dimethylamine‐borane (DMAB) kept at 323 K. The ZnO films had a wurtzite structure and exhibited an optical bandgap energy of 3.3 eV which is characteristic of ZnO. A 0.2 μm thick Z…
Foams can be created from coagulation of gas bubbles in liquid. After removal of cell faces, an open-cell foam remains consisting of a strut framework. In the past, mechanical properties were estimated by a small unit cell consisting of only a few struts. However, the random geometry of the foam can be of importance f…
The structure and magnetic properties of novel hybrid molecule-based magnets formed by combination of two magnetically active sublattices, the bimetallic oxalato-bridged honeycomb net [Mn II M III (ox) 3 ] (M II = Mn, Fe, Co, Cr, Ni, Cu; M III = Cr, Fe) and the organometallic cation decamethylferrocenium, are reported.
Henry reaction between nitroalkanes and aldehydes was performed in aqueous media, using NaOH 0.025M as catalyst, in the presence of cetyltrimethylammonium chloride (CTACl)as cationic surfactant.
Al-containing MCM-41 materials are prepared by grafting Al onto purely siliceous MCM-41; the resulting materials retain the hexagonal order and physical properties of the purely siliceous parent MCM-41 and exhibit higher Brønsted acid content compared to Al-MCM-41 prepared by direct hydrothermal synthesis.
Although spider silk has been studied for a number of years the structures of the proteins involved have yet to be definitely determined. X-ray diffraction and solid-state nuclear magnetic resonance (NMR) were used to study major ampullate (dragline) silk from Nephila clavipes. The silk was studied in its natural stat…
Tri- and tetra-dendron poly(amidoamine) (PAMAM) dendrimers were converted into hydrocarbon-soluble polymers and used as hydrophobic nanoscopic scaffolding by reacting their primary amino chain ends with various epoxyalkanes. These hydrophobically modified modules performed well as nanoscopic transport molecules. They…