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。
Poly(vinyl chloride) (PVC) thermal degradation is the result of a ‘zipper dehydrochlorination’ process that involves allylic chlorides as intermediates and is catalysed by hydrochloric acid. The degradation process can be stopped by PVC stabilisers, which either react with allylic chlorine atoms (primary stabilisers)…
It is worth noting that, with a few exceptions, the efforts to develop dielectric systems, especially for the LTD superconducting cables, are lagging behind the intense efforts to develop more efficient HT superconducting materials, tapes, and conductors. The results presented here and reported in the literature confi…
To understand the dehydration mechanisms of aluminum hydrates, the dehydration sequence of gibbsite (γ‐Al(OH) 3 ) by electron‐beam irradiation has been investigated using transmission electron microscope (TEM). The electron diffraction pattern indicates the formation of chi‐alumina in the initial dehydration stage. Th…
Porous polyimide films were prepared in two steps. The first step was the preparation of poly(urethane-imide) films by a reaction between a phenol-terminated polyurethane prepolymer and poly(amide acid) obtained from pyromellitic dianhydride (PMDA) and oxydianiline (ODA) followed by thermal treatment at 200 °C. The se…
Communication: Silicon carbide is an important non-oxide ceramic; however, production methods have until now remained difficult and/or expensive. In this communication is reported the production of silicon carbide via thermal decomposition from the novel Si-carbodiimide polymer poly-(methylsilasesquicarbodiimide), PSM…
<div class="htmlview paragraph">Three-way catalytic converters used on spark ignition engines have performance and durability characteristics which are effected by the thermal environment in which these operate. The design of the exhaust system and the location of the catalyst unit are important in controlling t…
The elastic field induced by a straight dislocation in a one-dimensional hexagonal quasicrystal with its line parallel to the quasiperiodic axis is obtained by superposition of the elastic fields of a pure edge part and a pure screw part. By extending the Peach-Koehler force to quasicrystals, the force between two par…
Past research on all-dielectric nonpolarizing beam splitters is reviewed. It is shown that, for a 50-nm spectral region, it is possible to design and manufacture a two-material nonpolarizing plate beam splitter for use at an angle of 45 degrees (with a measured rms reflectance of 0.50 +/- 0.01 for both s- and p-polari…
The crystal structure of the 224-residue protein dethiobiotin synthetase from Escherichia coli has been refined using X-ray diffraction data at 0.97 A resolution at 100 K. The model, consisting of 4143 protein atoms including 1859 H atoms and 436 solvent sites, was refined to a final R factor of 11.6% for all reflecti…
<div class="htmlview paragraph">In laboratory engine tests, a combination of platinum and cerium fuel additives with a platinum activated wall flow monolithic filter has been shown to be especially effective in the control of diesel particulate. Continuous regeneration of a filter can be achieved at temperatures…
The electrical properties of yttria (8 mol %)‐stabilized zirconia (YSZ)‐nickel oxide (NiO) composites were examined between 400 and 1000°C. The temperature and oxygen partial‐pressure dependence of conductivity and the electromotive force measurement of the galvanic cells helped to determine the electronic contributio…
Macroscopic properties of ferroelectric samples, including those in form of thin films, are, to large extent, influenced by their domain structure. In this paper the free energy is calculated for a plate-like sample composed of nonferroelectric surface layers and ferroelectric central part with antiparallel domains. T…
Homogeneous surface alignment of liquid crystals (5CB) is observed for films formed by coating with aqueous solutions of hydroxypropylcellulose (HPC) for high coating speeds and thin coating thicknesses. On the other hand, for films formed with isotropic ethanol solutions of HPC, 5CB molecules retain the flow-induced…
Abstract The influence of phase morphology and carbon black distribution on energy storage and dissipation during dynamic excitations of rubber blends is discussed. It is shown that differences in the local stiffness of the phases in the glass transition regime of unfilled blends lead to characteristic deviations of t…
A series of carbosilane dendrimer generations G x RF6 ( x = 1, 2, 3) with perfluorohexyl (−C 6 F 13 ) end groups as well as an unmodified G3 with allyl end groups has been investigated using dielectric spectroscopy. The experiments comprised a frequency range from 2 Hz to 1 GHz. The dendrimers show a fast (β) relaxati…
Molecular Dynamics (MD) simulations were used to study the relationship between structure and transport properties in five liquids (NaAlO 2, Na 2 Al 2 SiO 6, NaAlSiO 4, Na-AlSi 2 O 6, and NaAlSi 3 O 8 ) in the system NaAlO 2 -NaAlSi 3 O 8 at temperatures ranging from 4000 to 6000 K and pressures from 0 to 55 GPa. Seve…
The picosecond dynamics of noncovalent ensembles for energy transfer based on anion chelation are reported. The photoactive noncovalent complexes are assembled via salt-bridge formation between carboxyl-containing porphyrin photodonors and a monoprotonated pentapyrrolic sapphyrin acceptor. These complexes are formed w…
This paper describes a new technique for indexing powder diffraction data. The lattice parameters (unit-cell dimensions) { a , b , c ,α,β,γ} define the parameter space of the problem, and the aim is to find the optimal lattice parameters for a given experimental powder diffraction pattern. Conventional methods for ind…
We present a theoretical discussion of the reversible parking problem, which appears to be one of the simplest systems exhibiting glassy behavior. The existence of slow relaxation, nontrivial fluctuations, and an annealing effect can all be understood by recognizing that two different time scales are present in the pr…
We make a detailed analysis of the exact relativistic core-shell models recently proposed to describe a black hole or neutron star surrounded by an axially symmetric, hollow halo of matter and in a seminal sense also galaxies, since there are massive shell-like structures—as, for example, rings and shells—surrounding…