Materials Literature
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The structures, and Raman and infrared spectra of vitreous ${\mathrm{B}}_{2}$${\mathrm{O}}_{3}$ have been investigated by means of ab initio calculations. ab initio calculations. The calculated frequencies, structural parameters, and glass transition temperature ${\mathit{T}}_{\mathit{g}}$ are in good agreement with e…
Hot isostatically pressed Si 3 N 4 was coated with chemically vapor‐deposited Ta 2 O 5 , and subjected to oxidative and corrosive environments to determine the feasibility of using a Ta 2 O 5 coating for protecting Si 3 N 4 from hot corrosion. The coated structure was relatively stable at 1000 deg; C in pure O 2 . How…
Extended TTF‐based donor systems based for the first time on selenophene (see Fig.) are reported. Selenophene is an isologue of thiophene but has a stronger electron‐donating ability, a larger size, and a higher polarizability. These factors should lead to materials with increased bandwidth, improved dimensionality, i…
Calculations are presented for the local density of phonon states scrD(${\mathrm{\ensuremath{\omega}}}^{2}$), the lattice specific heat ${\mathit{C}}_{\mathit{v}}$, and the transmission coefficient of a particle through a layered quasicrystal whose ends are fixed. In this paper, scrD(${\mathrm{\ensuremath{\omega}}}^{2…
Abstract High resolution X‐ray diffraction measurements are performed on porous silicon samples (p + type, 40% porosity) of various thicknesses (from 0.03 to 20 μm). In the thicker samples narrow Bragg peaks are observed for as‐formed samples, with profiles close to those of dynamical diffraction theory. For thin samp…
In connection with the mechanism of reversible alignment change of nematic liquid crystals induced by photoisomerizable azobenzene molecules attached to a quartz surface, a static contact angle measurement was carried out for azo-modified plates before and after UV irradiation. The results were not in line with the so…
Transparent conducting ZnO:B films for solar cells were produced by DC magnetron sputtering in B 2 H 6 -Ar mixtures. Low-resistivity textured films could be obtained at relatively low substrate temperatures of 150-200° C. The resistivity, electron mobility and carrier concentration were 4×10 -4 Ω cm, 60 cm 2 / Vs and…
Abstract All of the blend systems studied to date show a tendency to have an uneven distribution of crosslinks between the phases; this must be taken to be the norm, with instances of near-even crosslinking being the exception. When the crosslink distribution has been made to be near even, the properties investigated…
Three metallization schemes, namely Al/Si, Ti-Au and TiWN-Au contacts on B-doped polycrystalline diamond films have been compared. After annealing at 450/spl deg/C in nitrogen Al/Si contacts show the lowest contact resistivity in the order of /spl sim/10/sup -7/ /spl Omega/ cm/sup 2/. TiWN-Au contacts were found to be…
The problem of a joint of dissimilar materials with arbitrary edge angles exposed to thermal loading is treated. Emphasis is placed on the investigation of the stress distribution around the singular point for complex singular eigenvalues. For this case, an analytical form of the stress is obtained. Some examples are…
Studies have been carried out on the compatibilization of polypropylene and nylon using maleic anhydride grafted polypropylene (Polybond™ 3002). Solution and FTIR studies on the resin indicated that the compatibilizer reacted with nylon. The usefulness of the compatibilizer has been demonstrated for the recycling of s…
Dynamical theories of atomic number sensitive image (or Z-contrast image) formed by thermal diffusely scattered (TDS) electrons are proposed based on first-principles considerations. `Exact' theories are derived for simulating images obtained either in scanning transmission electron microscopy (STEM) using an annular…
SUMMARY X‐ray microanalysis of non‐biological and biological specimens was carried out in the environmental scanning electron microscope (ESEM) under different conditions of specimen distance (the distance travelled by the electron probe within the specimen chamber) and chamber atmosphere. Using both water vapour and…
The occurrence of cop-like copper resistance determinants homologous to the cop genes of Pseudomonas syringae among bacteria isolated from a water distribution system experiencing copper corrosion was investigated in this study. It was found that at least 49% of the copper-resistant bacteria and less than 15% of the c…
Abstract There is considerable uncertainty about the extent of mineral weathering and neosynthesis in arid soils. Although researchers have speculated that smectite neosynthesis can occur in soils containing opaline silica cement, no evidence has been presented to support this hypothesis. We investigated the mineralog…
The simulation of the structure of aromatic and quinoid poly(isothianaphthene) (PITN) has been improved, by the synthesis of new model compounds. The C-13 NMR investigation confirms our previous results that the geometric structure of this low-band-gap conducting polymer shows a strong quinoid character. For the aroma…
Abstract The effect of temperature over the range −196 to 150°C on the crosslinking of polyethylenes irradiated by electron beam has been investigated on the basis of gel content determination and Fourier transform infra‐red (FTIR) spectroscopy. The crosslinking efficiency increases significantly with increasing irrad…
Fermi level shift in n-type perylene pigment film was measured by the Kelvin vibrating capacitor method. Purification of pigment by reactive sublimation under methylamine atmosphere caused negative shift of the Fermi level due to the effective removal of unknown but specific impurity acting as an acceptor. On the othe…
Shape memory alloys (SMA) have recently been proposed and demonstrated for several active control applications. However, there is only limited experimental information available on the properties of the SMA. The present paper focuses on variations of the dynamical Young's modulus, the damping characteristics, and the…
Abstract The use of functionalised 2,2':6',2″‐terpyridines and multi‐domain ligands based upon this metal‐binding motif for the assembly of co‐ordination oligomers is discussed. The extension of the methodology to the preparation of helical polymers is demonstrated.