Materials Literature
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With use of the self-consistent orthogonalized linear combination of atomic orbitals method in the local-density approximation, the electronic structures and the optical properties of eight different polycrystalline phases of ${\mathrm{SiO}}_{2}$ have been studied: They are \ensuremath{\alpha}-quartz, \ensuremath{\bet…
We propose what is to our knowledge the first use of a Pr(3+)-doped fluoride fiber amplifier as a practical amplifier operating at the 1.3-microm band, based on a demonstration of signal amplification and a spectroscopic investigation. The feasibility of the fluoride fiber amplifier is confirmed.
We have investigated the effects of reactant residence time on the properties of microwave-assisted chemical vapor deposited diamond films. Using a constant gas pressure of 40 Torr and gas composition of 1% CH4 in H2, the total gas flow rate was adjusted from 25 to 800 sccm which corresponds to apparent chamber reside…
The distribution of local stress in an atomic system can be calculated from its mechanical definition. While this leads, for a homogeneous system, to an expression equivalent to that derived from the virial theorem (thermodynamic definition), when local inhomogeneities are present the equivalence can be demonstrated o…
We report an electron-energy-loss-spectroscopy study of the characteristic oxygen K and iron ${\mathit{L}}_{2,3}$ edges in FeO, ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$, \ensuremath{\alpha}-${\mathrm{Fe}}_{2}$${\mathrm{O}}_{3}$, and \ensuremath{\gamma}-${\mathrm{Fe}}_{2}$${\mathrm{O}}_{3}$ thin films. Data have been proc…
A mostly single bcc phase with nanoscale grain sizes of 10 to 20 nm was found to form by annealing amorphous Fe-Zr-B, Fe-Hf-B, and Fe-M-B-Cu(M=Ti, Zr, Hf, Nb, and Ta) alloys for 3.6 ks in the range of 723 to 923 K. The high permeability (μe) above 10 000 at 1 kHz combined with high saturation magnetization (Bs) above…
Field effect devices have been formed in which the active layer is a thin film of poly(3-methylthiophene) grown electrochemically onto preformed source and drain electrodes. Although a field effect is present after electrochemical undoping, stable device characteristics with a high modulation ratio are obtained only a…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Irradiation of polypropylene in air leads to severe oxidative degradation, discoloration, and eventually embrittlement. The mechanisms involved have been examined and methods of stabilization have been explored in this study. Although this work has concentrated on radiation effects on polypropylene, the methods for st…
R67 dihydrofolate reductase (DHFR) is a novel protein that provides clinical resistance to the antibacterial drug trimethoprim. The crystal structure of a dimeric form of R67 DHFR indicates the first 16 amino acids are disordered [Matthews et al. (1986) Biochemistry 25, 4194-4204]. To investigate whether these amino a…
Formation energies of the vacancy and self-interstitial in Al, as well as energies of intrinsic, extrinsic and twin-boundary stacking faults are calculated from first principles. The electronic structure and forces on the atoms are calculated in the framework of the augmented plane wave method using the algorithm prop…
A 50 °C shift in Curie temperature has been observed for c-axis oriented PbTiO3 thin films using x-ray diffraction. An analysis of the electrostrictive strain based on the Devonshire thermodynamic formalism showed that the shift in the Curie point for these films can be plausibly explained by an effective two-dimensio…
We review recent theoretical developments of microscopic lattice and continuum models of the kinetics of irreversible monolayer and multilayer surface adsorption. Such models have been used to describe adhesion and reaction processes of colloidal particles and proteins at solid surfaces. Theoretical results surveyed h…
Abstract Novel techniques are introduced to render the classical split Hopkinson bar apparatus suitable for dynamic recovery experiments, where samples can be subjected to a single pulse of pre-assigned shape and duration, and then recovered without any additional loading, for post-test characterization; i. e., techni…
Die Algenflora der schirmacheroase (Ostantarktika) , Die Algenflora der schirmacheroase (Ostantarktika) , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
Abstract The area under the linear loss modulus‐temperature curves, LA, has been shown to be related to the chemical composition of the material. In addition, it can be significantly affected by morphology in multicomponent polymer systems. To characterize LA quantitatively, base‐line corrections for instrumental cont…
Abstract This is the third in a series of papers in which the thermal degradation of ethylene‐vinyl acetate (EVA) and ethylene‐butyl acrylate (EBA) copolymers are compared. The EBA samples contained 0.8, 1.6, and 5.4 mol % butyl acrylate (BA), respectively, and the EVA samples 1.2 and 6.7 mol % vinyl acetate (VA). The…
Abstract This is the second in a series of papers in which the thermal degradation of ethylene‐vinyl acetate (EVA) and ethylene‐butyl acrylate (EBA) copolymers are compared. The EBA samples contain 0.8, 1.6, and 5.4 mol % butyl acrylate (BA), respectively, and the EVA samples 1.2 and 6.7 mol % vinyl acetate (VA). The…
Abstract Surface properties of a number of commercial thermoplastic polymer films were investigated before and after brief exposures to RF induced, low temperature gas plasmas. Water wettability and adhesion of vapor deposited aluminum to thin films (8–12 micron) of polyethylene, polypropylene, polyester, polysulfone,…
Abstract This is the first in a series of papers in which structural changes during thermal degradation of ethylene‐vinyl acetate (EVA) and ethylene‐butyl acrylate (EBA) copolymers are compared. EVA, containing 11.4 mol% vinyl acetate (VA) and EBA, containing 5.4 mol% butyl acrylate (BA), were pyrolyzed at 280°C in ni…