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 Three different models have been reported previously to describe the kinetics of the transformation of smectite to illite (Pytte 1982; Velde and Vasseur 1992; Huang et al. 1993). In order to evaluate the general utility of these models to calculate the timing and extent of this transformation, each model was…
Galvanostatic reduction of and sputter‐deposited thin films was investigated as a model for reduction of the passive film on iron. X‐ray absorption near‐edge spectroscopy was used to perform in situ measurements of the valence state and dissolution (thinning rate) of the films during reduction. In borate buffer, the r…
The modABCD operon, located at 17 min on the Escherichia coli chromosome, encodes the protein components of a high affinity molybdate uptake system. Sequence analysis of the modA gene (GenBank L34009) predicts that it encodes a periplasmic binding protein based on the presence of a leader-like sequence at its N termin…
Effect of oxygen concentration in the sputtering ambient on the microstructure, electrical and optical properties of radio-frequency magnetron-sputtered indium tin oxide films , Wen-Fa Wu, Bi-Shiou Chiou
A new parameterization is defined for the quantitative description of octahedral tilting in orthorhombic and tetragonal perovskites. It contains six parameters, s 1 , s 2 , s 3 , θ x , θ y and θ z . s 1 , s 2 and s 3 refer to the lengths of the lines or `stalks' joining pairs of opposite octahedral vertices, and θ x ,…
Electrical impedance measurements have been made in the frequency range 5 Hz to 10 MHz in pure poly(ethylene oxide) having a molecular weight of 600,000 from 12 K nearly up to the melting point of the crystalline phase (about 330 K). A pronounced relaxation peak in the dielectric loss and a corresponding step in the d…
Abstract In monolith reactors with catalytic washcoat, intraphase diffusion effects have often been underestimated. This paper presents numerical simulations of diffusion/reaction in the washcoat of a catalytic monolith reactor. The problem is solved in two dimensions for the washcoat geometry obtained in a 1‐mm squar…
The rate of capillary rise of a liquid into a porous medium made up of consolidated particulates is analyzed. The infiltration distance is parabolic in time and can be modeled using the Washburn analysis. The effective pore radius is measured to be one to two orders of magnitude smaller than the particle size, particl…
The magnetic properties and field-dependent specific heat of melt-spun amorphous RE70TM30 (RE=Gd, Tb, Dy, Ho and Er; TM=Fe and Ni) and Gd65Co35 alloys were investigated as potential magnetic refrigerants. Essentially zero magnetic hysteresis was observed in all the Gd–TM alloys at temperatures from 5 K up to the order…
In the present bond-valence concept the bond-valence parameter r o is treated as constant for a given pair of atoms, and it is assumed that the bond valence s ij is a function of the corresponding bond length D ij , and that the atomic valence is an integer equal to the formal oxidation number for V i derived from sto…
Sodium sulfate, Na2SO4, has been reported to exist in five polymorphous forms labelled I–V. Structure analysis has been reported on three of the polymorphs and thermal analysis on all of them. The system has been reinvestigated by differential scanning calorimetry (DSC) and by X-ray powder diffraction at several tempe…
Lead titanate (PT) sols were prepared using propanediol, butanediol, or pentanediol solutions of lead acetate trihydrate and titanium diisopropoxide bis(acetylacetonate). Precursor sols for PbZr 0.53 Ti 0.47 O 3 (PZT) films were prepared from propanediol solutions, with zirconium tetrapropoxide being used as the zirco…
Mathematical and computational evidence that strongly suggests that optimal solutions exist to single-band, normal-incidence antireflection coating problems is presented. It is shown that efficient synthesis and refinement techniques can quickly and accurately find such solutions. Several visible and infrared antirefl…
We present an algorithm to simulate the packing of large samples of spheres chosen from a truncated log-normal distribution for either correlated or uncorrelated distributions. Use of a concept known as the porosity index provides a means to control the final porosity of a packed sample within a range that spans limit…
The crystal structures of four hydroxylapatite (HA) samples prepared from solutions in the presence of 10, 15, 25 and 30 Mg-atom-% have been investigated by X-ray powder pattern fitting. The total magnesium content of the solid samples, as determined by chemical analysis, was 4.9, 14.1, 20.4 and 30.6 Mg-atom-%, respec…
Magnesium hydroxide, Mg(OH) 2 : M r = 58.3, trigonal, P {\bar 3} m 1, a = 3.148 (1), c = 4.779 (2) Å, V = 41.015 Å 3 , D x = 2.36 g cm −3 at room temperature; a = 3.145 (1), c = 4.740 (2) Å, V = 40.602 Å 3 , D x = 2.39 g cm −3 at 70 K; Z = 1, λ = 0.8330 (5) Å, μ = 1.78 cm −1 , F (000) = 9.503 fm; final R = 2.42, wR =…
Trichothiodystrophy (TTD) is a rare autosomal recessive disorder characterized by brittle hair with reduced sulfur content, ichthyosis, peculiar face, and mental and growth retardation. Clinical photosensitivity is present in approximately 50% of TTD patients but is not associated with an elevated frequency of cancers…
The Hamaker constants of eight different ceramic materials, 6H‐SiC, tetragonal, partially stabilized ZrO 2 (3% Y 2 O 3 ), β‐Si 3 N 4 , α‐Al 2 O 3 , Y 2 O 3 , sapphire (single‐crystal α‐Al 2 O 3 ), MgO, MgAl 2 O 4 , and fused silica, across air, water, and n ‐dodecane at room temperature and across silica at 2000 K hav…
The deformation pattern at grain boundaries and at triple junctions in polycrystalline high purity aluminium (99.999%) has been studied by electron back scattering pattern (EBSP) observations. Specimens of two different grain sizes rolled to give 5% and 30% reductions have been examined by these different EBSP scans:…
The thermoelectric effect and its systematic variation with doping level ($x$), temperature ($T$), and external magnetic field ($H$) have been investigated for crystals of double-exchange ferromagnets, ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ ($0.15<~x<~0.50$). Large $T$- an…