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 Two common approachs to flame retard flexible PVC are phosphate ester plasticizers and antimony oxide. When used individually, each displays excellent flame suppressing characteristics. However, the combination of the two has been reported to show lower than expected flame resistance. Zinc borate plays a syne…
Measurements were made of the transition resistivities of an aluminum-porous silicon contact and the resistivity of the surface region of the porous material after short-term annealing in an inert medium at temperatures between 300 and 550 °C. It was shown that the parameters of the contacts are determined by the pore…
Bianisotropic media may be characterized as a general class of linear media which exhibit so-called magnetoelectric coupling between the electric and magnetic fields. Bianisotropic composites are attracting considerable attention in view of their potential usefulness and new fundamental problems. A bianisotropic cryst…
The phosphorylated form of the N-terminal domain of enzyme I of the phosphoenolpyruvate:sugar phosphotransferase system of Escherichia coli has been investigated by one-bond and long-range 1H-15N correlation spectroscopy. The active site His 189 is phosphorylated at the Nepsilon2 position and has a pKa of 7.3, which i…
When the rate of glucose addition to nongrowing Streptococcus bovis cell suspensions was increased, the fermentation was homolactic, fructose-1,6-diphosphate (FDP) increased, intracellular inorganic phosphate (P(i)) declined, and the energy-spilling rate increased. ATP and ADP were not significantly affected by glucos…
Silica supported methyltrioxorhenium complex of γ-(2,2′-dipyridyl)-aminopropyl polysiloxane (III) has been synthesized and demonstrated as a novel catalyst of high activity, stability and improved selectivity for epoxidation of alkenes with hydrogen peroxide at room temperature. The catalyst can be recycled at least f…
The crystallization process of the Ag or Cu doped Sb/sub 2/Te/sub 3/ amorphous film was investigated by isothermal treatment for one hour at 100/spl deg/C, 200/spl deg/C and 300/spl deg/C respectively. The crystallization temperatures of Ag/sub 8.3/Sb/sub 34.9/Te/sub 56.8/ and Cu/sub 8.4/Sb/sub 35.1/Te/sub 56.5/ films…
Soft x-ray magnetic circular dichroism (MCD) data were collected at the Co $L$ edges from a series of epitaxial $R\ensuremath{-}\mathrm{Co}$ ($R=\mathrm{P}\mathrm{r},\phantom{\rule{0ex}{0ex}}\mathrm{N}\mathrm{d},\phantom{\rule{0ex}{0ex}}\mathrm{S}\mathrm{m},\phantom{\rule{0ex}{0ex}}\mathrm{D}\mathrm{y},\phantom{\rule{…
Basic copper sulfates, , and cuprite, , are the major corrosion products found during field exposure of copper. The active species of the atmosphere which lead to formation of these corrosion products are, however, still uncertain. In this study, we investigated whether submicron acid ammonium sulfate particles, , can…
A behavioral model of magnetic materials is presented. This model takes into account both hysteresis and dynamic phenomena. It predicts B(H), /spl phi/(t) and d/spl phi/(t)/dt characteristics, and a few pieces of experimental data are needed to identify its parameters. In this paper, the authors propose to validate th…
Porphyrins with steric hindrance at the periphery are known to exhibit severely non-planar macrocycle conformations. Among other dodecasubstituted porphyrins, the title compound has been studied widely and shows a typical saddle-distorted macrocycle. The specific conformation of the porphyrin leads to the formation of…
A diffraction grating technology based upon volume-phase holograms shows promise of enhanced performance for many applications in astronomical spectroscopy over classical surface-relief grating technology. We present a discussion of the underlying physics of a volume-phase grating, give some theoretical performance ch…
A finite element, numerical model of a solid railway wheel was perfected permitting the simulation of a block braking operation. The analyses performed, backed by experimental tests, permitted the degree of variation in the residual stress state (induced by differential quenching heat treatment and successive temperin…
Hen egg white lysozyme was employed for studying aggregation and nucleation events induced by simple electrolytes such as NaCl while the process was monitored by time-resolved, small-angle static light scattering. The fractal dimension, the weight-average molecular weight, the mean radius of gyration and the homogenei…
Microbial corrosion scenarios based on the action of sulfate-reducing bacteria (SRB) under disbonded tape coatings on the outside of gas pipelines have been described previously. Secondary oxidation of these sites leads to formation of unique corrosion products. These have been associated with serious corrosion damage…
A concept is outlined to incorporate dislocation climb in a discrete three-dimensional model of dislocation dynamics. Each dislocation line consists of a sequence of interconnected piecewise straight segments which are embedded in a homogeneous linear elastic medium. The dynamics are described by solving Newton's equa…
The electrodynamic balance (EDB) is demonstrated to be useful for the in situ study of aqueous droplet solidification. We have used an EDB to study the solidification of solution droplets used for ceramic powder synthesis by spray pyrolysis. The mass change and the elastic light scattering of the drying 20 μm solution…
High-modulus and high-strength carbon fibers were submitted to oxidation plus sizing and grinding treatments. Subsequent changes at the fiber surfaces were studied by Raman spectrometry. X-ray diffractograms and Raman spectra of the fresh fibers were compared with those of other carbon materials with different graphit…
Sol–gel techniques have been used to produce various high temperature ceramic matrix composites including Ni/α-Al2O3, Fe/α-Al2O3, Ni/ZrO2, SiC(whisker)/α-Al2O3, and SiC(platelet)/α-Al2O3, as well as chemically modified versions of some of these systems. In all cases, the composites have displayed uniform microstructur…
The fine structure of Haslea ostrearia Simonsen, a diatom that is able to synthesize a blue pigment (marennine), is described. Ultrastructurally, this microalga has a typical naviculoid organization, but marked changes occur depending on the stage of cell blueing by accumulation of marennine. A comparison of the ultra…