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。
Explicit formulas for the calculation of stress are presented based on the stress theorem and the local-density-functional approximation. Norm-conserving pseudopotentials are applied in a plane-wave basis for calculations on the semiconductors Si, Ge, and GaAs. Besides the lattice constants and bulk moduli, complete s…
Optical and electrical properties of transparent conductive oxide films of undoped and doped SnO 2 and In 2 O 3 prepared using the pyrolysis spray method were studied. The optical constants extracted from transmittance and reflectance measurements between 0.25 and 3 mu m are interpreted to give values of the direct al…
The optical energy gap of amorphous Se powder has been determined by a photo-acoustic method and has been found to be 1.99+or-0.02 eV. On annealing, the gap decreases linearly as a function of annealing temperature towards that of the crystalline selenium.
A number of organic materials have been observed to possess very large intrinsic nonlinear optical susceptibilities. Second and third order susceptibilities have been measured to be larger than any inorganic materials. These large susceptibilities as well as potentially very fast switching times arise from certain cha…
Measurement by a vibrating capacitor probe of the variation with temperature of the surface potential of freshly cleaved surfaces of sodium chloride single crystals confirm the basic characteristics predicted by point defect theory: negative potentials at low temperature, positive potentials at high temperature, and a…
Abstract The phenomenon of scale formation has been experienced by generations of different races whenever water has been used. It was formed in Roman aqueducts and canals and is also found in the present day in the most modern oil production operations. The most commonly found scales in this industry are the carbonat…
Abstract Many real, exothermic systems involve more than one simultaneous reaction. In part I of this series (Boddington, T., Gray, P. & Wake, G. C. Proc. R. Soc. Lond. A 393, 85 (1984)) a simple, unifying approach to the behaviour of such multi-reaction systems was proposed. It built on a communal activation ener…
The temperature-composition phase diagram of the ${\mathrm{Ni}}_{1\ensuremath{-}x}{\mathrm{Pt}}_{x}$ system was determined by x-ray diffraction and in situ high-temperature measurements of electrical resistivity. The Curie temperatures were also determined for both disordered and ordered alloys. Our results provide di…
Polystyrene chains in solution have been crosslinked by $\ensuremath{\gamma}$ irradiation. The gelation reaction has been stopped at various stages before the gel point and the size distribution function has been measured. We show that the distribution functions obey a simple scaling law.
There is a possibility that the phase separation process is coupled with other ordering processes such as crystallization. New types of phase separation behavior during the crystallization process in polymer blends with phase diagram are presented probably for the first time. Two different types of nonequilibrium phen…
A new processing scheme suitable for commercial production has been developed so that the Fe-28Cr-10.5Co magnet alloy can be used as a replacement for high cobalt Vicalloy (52Co-38Fe-10V) in thin strip (1-2mil) permanent magnet applications, offering the advantages of lower cost, lower cobalt content, improved rust re…
The magnetic properties and cation distribution of a new ferrimagnetic R-type hexagonal ferrite have been studied from isothermal magnetization and Mössbauer spectroscopy measurements. The compound BaFe4Mn2O11 possess a collinear spin structure and a strong uniaxial magnetic anistropy. By means of the law of approach…
The surface features of FE80.5(B,C,Si)19.5amorphous ribbons were measured by an optical method, and the permeability change by surface roughness and the relation between core loss and periodic surface roughness, which is called "fish scale", were investigated. The permeability decreased with increasing surface roughne…
An electrooptic effect in the blue phase of the cholesteric mixture S811- and the nematic mixture N5 is reported. To demonstrate this effect ac voltages (f = 1000 Hz) between 0 and 150 V were applied. Wavelength shifts of 70 nm were obtained.
This article is concerned with the extension of the Renkin-Crone model to a case of saturable transport across the blood-brain barrier, i.e., when the apparent permeability-surface area product is concentration dependent. A well-mixed tissue compartment is assumed, together with a simple symmetric saturable transport…
NO2 does not appear to be a primary product in the oxidation of copper metal by nitric acid.
Implications of the hydridation of the ternary borides RE2Fe14B on the physical, crystal structure and mechanical cohesion are discussed. Some examples are given, more particularly with RE = Y, Ce, Dy.
The chemical processes by which tritium can be converted to tritiated water have been examined by reviewing the available literature on these processes. Gas phase conversion reactions at room temperature are slow and they do not contribute significantly to any observed conversion following releases of elemental tritiu…
Issues are discussed that are critical in determining tritium loss from helium-cooled fusion breeding blankets. These issues are: (a) applicability of present models to permeation at low tritium pressures, (b) effectiveness of oxide layers in reducing permeation, (c) effectiveness of hydrogen addition as a means to lo…
Calculations for the magnetic dipolar contribution to the magnetic anisotropy of BaFe12O19 and LaFe11ZnO19 M-type and BaFe4Mn2O11 R-type hexagonal ferrites have been made. Our calculations take into account all the magnetic moments existing within a sphere with a radius of 118 Å, from which good convergence is reached…