Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
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…
Abstract An attempt is made to develop a novel series of cable sheathing compounds with variation in chlorine content and sufficient fire retardance and unique low‐smoke characteristics. These are prepared by blending PVC and functionalized polyolefins in different compositions. PE and EPDM have been functionalized by…
The amino acid sequence and part of the DNA sequence of a glutamic acid-specific serine protease from Streptomyces griseus is reported. This protease is shown to be homologous with other serine proteases. An improved purification protocol for this enzyme is described.
The structure of fructose-1,6-bisphosphate aldolase from Drosophila melanogaster has been determined by X-ray diffraction at 2.5 A resolution. The insect enzyme crystallizes in space group P2(1)2(1)2(1) with lattice replacement with rabbit muscle aldolase as a search model has been employed to solve the structure. To…
We report on the growth of high-quality diamond using a microwave plasma chemical vapor deposition (CVD) system in which the feed gas contains no hydrocarbons, but instead the source of carbon is a graphite piece which resides within the plasma volume. Results of experiments using this technique by itself and in combi…
The optical-absorption spectrum of ${\mathrm{Li}}_{6}$ has been observed by depletion spectroscopy in the 400--700-nm range. The experimetnal results are compared with theoretical spectra calculated for the three ${\mathrm{Li}}_{6}$ structures in competition and we have been able to unambiguously determine the most st…
Ferroelectric thin films of Bi4Ti3O12 were fabricated on several types of substrates, including quartz, steel plates, and indium-tin-oxide coated glass slides, by sol-gel technique. Crystalline, transparent, and crack-free films of 5000 Å thickness were fabricated by spinning and post-deposition annealing at a tempera…
The optical properties of the stable icosahedral quasicrystal ${\mathrm{Al}}_{63.5}$${\mathrm{Cu}}_{24.5}$${\mathrm{Fe}}_{12}$ have been measured from 40 to 25 000 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ at 300 and 80 K. Unlike metallic glasses with a Drude spectrum with strong elastic scattering by disorder, or se…
Abstract Structures and stability ranges of the YBa 2 Cu 3 O 7–x interface were studied with AES, SIMS, XPS, and TEM. For silicon substrates, the formation of Ba silicates can be detected which even at T = 550 K leads to reduced T c values and non‐epitaxial growth of YBa 2 Cu 3 O 7–x (YBCO). Yttria stabilized zirconia…
A novel electron beam (EB) spot size measurement method is proposed. In this method, EB spot size is obtained from the relationship between the width of the trenches in the reference sample and the intensity profile of backscattered electrons. Selective chemical etching of a GaAlAs/GaAs superlattice produces an ideal…
The authors provide a detailed loss computation of a sheet wound transformer. The aim is to develop a simplified two-dimensional model in which 3-D effects due are introduced by correction factors. The present solution is based on analytical computation of extra losses in bus bars, numerical determination of bus bar s…
The potential use of POWERCORE strip for the fabrication of low-loss stacked cores was investigated. Two three-phase transformer cores having different joint configurations were assembled and tested (core A: 90 degrees butt and lap T and corner joints; core B: 45-90 degrees T-joints and 45 degrees mitred corner joints…
Rhomboedrisch verzerrt aufgrund der Form der organischen Ionen ist die Antiperowskitstruktur aller vier ternären Salze 1 , die durch Elektrokristallisation der Komponenten Tetrathiafulvalen (TTF), Tetrabutylammoniumhalogenohexamolybdat und Tetrabutylammoniumhalogenid erhalten wurden. Die verbleibende dreizählige Symme…
Abstract The dielectric spectrum is measured up to 72 GHz of solutions of polyvinylpyrrolidone (PVP) in tetramethylurea (TMU), dimethylethylene urea and dimethylpropylene urea. Concentrations are up to a monomole fraction of 0.65 (PVP 1200) or 0.5 (PVP 40 000). Measuring temperatures are 20CC for all systems and addit…
Ions in the mass range from H to Xe have been used at energies from a few keV to more than a GeV to cause atomic rearrangement and consequent formation of conducting grains of carbonized material in several polymers. Generally, the conductivity increases dramatically-- by several orders of magnitude--until finally dem…
Synthesis and characterization of thermally stable polycyanurate is being reported here. The polycyanurate is a copolymer obtained by interfacial polycondensation of bisphenol-A, bisphenol-F and 2-methoxy-4, 6-dichloro-s-triazine. The copolymer obtained is characterized by various means. Spectroscopic characterization…
$^{15}\mathrm{N}$ nuclear-magnetic-resonance (NMR) measurements are reported on solid $^{15}\mathrm{NNO}$. Because of the anisotropic chemical shift and intramolecular dipole coupling, molecular reorientation results in a change in the nuclear-precession frequency. The rate of combined-translation-rotation jumps in th…
When undoped Yttrium Stabilized Zirconia is exposed either to reducing atmospheres or to electrical currents it becomes coloured. In this paper we present the results of a systematic study applying optical and EPR techniques to zirconia single crystals stabilized by calcium or yttrium, in which defects were produced b…