Materials Literature
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The interface between the surfaces of clay minerals and other materials (aqueous solution, organic moieties, biomolecules, etc. ) is of great importance to many geological, technological and biological processes. The examination of the structure and composition of mineral surfaces is advancing rapidly. However, the cr…
Monte Carlo methods were used to calculate heat capacities as functions of temperature for classical atomic clusters of aggregate sizes 25⩽N⩽60 that were bound by pairwise Lennard-Jones potentials. The parallel tempering method was used to overcome convergence difficulties due to quasiergodicity in the solid-liquid ph…
Carbon coatings are widely used to modify surfaces of materials and improve their tribological properties. In this work, carbon layers were formed on various types of sintered and CVD silicon carbide (SiC) using a novel technique involving a reaction with chlorine and chlorine-hydrogen gas mixtures at 1000 °C. Followi…
Ceramic foams in the system Si‐O‐C, possessing different bulk densities and morphologies, were obtained from preceramic polymers using two different direct foaming approaches. The electric properties of the foams were varied by adding suitable fillers to the precursor mixtures in amounts up to 80 wt%. The electrical c…
The structure and electronic transport properties of polymer‐derived pristine and boron‐doped silicon carbonitride ceramics have been studied, with particular emphasis on understanding the effect of annealing treatments. Structural analysis using the radial distribution function formalism showed that the local structu…
Alumina and titania supported tin dioxide catalysts presenting various Sn loadings were prepared by impregnation. The acidity and basicity of the samples were determined by adsorption of ammonia and sulfur dioxide, respectively, using adsorption microcalorimetry and X-ray photoelectron spectroscopy. The surface reacti…
A combination of the well-defined character of π-conjugated oligomers and the material properties of polymers is displayed by the supramolecular hydrogen-bonded π-conjugated architectures of the title compounds (see scheme). These compounds have been successfully used for the first time in electronic devices.
We have performed molecular dynamics simulations of amorphous Si 3 N 4 containing boron (Si‐B‐N). We have examined short‐range atomic arrangements and self‐diffusion constants of amorphous Si‐B‐N systems with various boron contents. Our simulations show that boron atoms are threefold coordinated by nitrogen atoms and…
A hydrophobic, CF3-functionalized silica aerogel has been applied to water-oil mixtures to determine oil absorbing capacity of the solid aerogel. Preliminary tests on Prudhoe Bay crude oil mixed with salt water, using the aerogel in powder form, show three regimes for absorbing based on oil to aerogel wt ratios (O/A):…
This paper demonstrates the viability of in-situ transmission electron microscopy for studying the deformation mechanisms of polymer nano-composites. In-situ straining studies are performed on carbon multiwalled nanotube (MWNT)-polystyrene composite films. The experiments show that load transfer across the nanotube-po…
The crystallographic and group theoretical analysis of the structural phase transitions in perovskite and perovskite-like crystals is reviewed. We include ABX3 perovskites and their relative crystals of ReO3 type (G0 = O1 h), elpasolites, cryolites and their relatives (G0 = O5 h), layered crystals of T1AlF4 series (G0…
The lattice thermal conductivity of a thermoelectric material can be significantly reduced at ordinary temperatures by boundary scattering but the beneficial effect on the figure of merit can sometimes be more than offset by boundary scattering of the charge carriers. Here we extend the previous theory to include both…
The oxidation behavior of three precursor‐derived ceramics—Si 4.46 BC 7.32 N 4.40 (AMF2p), Si 2.72 BC 4.51 N 2.69 (AMF3p), and Si 3.08 BC 4.39 N 2.28 (T2/1p)—was investigated at 1300° and 1500°C. Scale growth at 1500°C in air can be approximated by a parabolic rate law with rate constants of 0.0599 and 0.0593 μm 2 /h…
The Nd–Nd and Nd–Yb energy transfer processes are studied in lead fluoroindogallate glasses with the following molar composition: 30PbF2–20GaF3–15InF3–15ZnF2–(20–X)CaF2–XNdF3 (with X=0.1, 0.5, 1, 2, 4, and 5), 30PbF2–20GaF3–15InF3–15ZnF2–(20–X)CaF2–XYbF3 (with X=0.1, 0.5, 1, 2, 3, and 5), and 30PbF2–20GaF3–15InF3–15Zn…
Magnetoliposomes (MLs) conjugated with an antibody fragment to give specificity to a tumor were applied to hyperthermia for cancer. The Fab' fragment of the G250 antibody, which binds to MN antigen on many types of human renal cell carcinoma, was cross-linked to N-(6-maleimidocaproyloxy)-dipalmitoyl phosphatidylethano…
Macromolecules conjugated with polyethylene glycol (PEG) acquire more hydrophilicity, resulting in a longer half-life in circulation and lower immunogenicity. Two novel conjugates for MRI contrast agents were synthesized from a generation-4 polyamidoamine dendrimer (G4D), 2-(p-isothiocyanatobenzyl)-6-methyl-diethylene…
The luminescence of nanocrystalline cubic yttria has been measured for 300 and 80 K. A blueshift and a broadening of the absorption edge, both depending on the particle size were found. The energy of the radiation emitted due to the recombination of a bound exciton does not depend on particle size. The observations ar…
The lithium tetraborate (Li 2 B 4 O 7 ; LBO) crystals were successfully grown by Czochralski technique. The frequency and temperature dependences of dielectric constant and a c conductivity were investigated in the frequency from 100 Hz to 10 MHz along c -axis. The dielectric anomaly with broad peak about 300°C was ob…
A detailed study of the excited state energy migration dynamics that take place within an assembly of Ru(II) and Os(II) polypyridyl complexes linked together through a polymer backbone is presented. The energy migration process is initiated by the photoexcitation of the metal-to-ligand charge transfer (MLCT) transitio…
A simple methodfor the fabrication of anodic aluminum oxide films (AOFs) with perfectly ordered structures (see Figure) is presented by these authors. A common optical grating is used to prepattern the aluminum substrate, which is subsequently anodized under mild conditions to yield an AOF with a photonic bandgap in t…