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。
A free-energy expression (differing in its symmetry from that of McMillan) is proposed for describing charge-density-wave (CDW) states in transition-metal dichalcogenides having trigonal-prismatically coordinated layers (e.g., 2H-Ta${\mathrm{Se}}_{2}$). An analysis of the single CDW state is given. In disagreement wit…
The reacton of hydrogen with hydroxyl-free vitreous silica has been measured for temperatures between 500 and 850 °C, pressures between 0.132 and 5.78 atm, and sample thicknesses between 0.057 and 1.06 cm. The results can be explained by a simple model often used to explain tarnishing reactions. This model assumes tha…
The electrical properties of (MxV1–x)2O3 (M = A1, Cr, Fe, Ga, Rh, Ti) have been investigated. Only Al- and Cr-doped V2O3 exhibit electrical transitions close to room temperature. X-ray diffraction shows that no critical lattice parameter can be identified to correlate with the occurrence or absence of this transition.…
Abstract The band structure of Mg x Zn 1‐x Te alloys is studied using a double beam wavelength modulated system in first derivative mode. Modulated reflectivity measurements are made from 82 to 300 K within spectral range 2500 to 5400 Å. Structures corresponding to the E 0 , E 0 + Δ 0 , E 1 , E 1 + Δ 1 , e 1 and e 1 +…
The longitudinal magnetoresistance of high-purity aluminium single crystals has been measured by point-contact four-probe method at 4.2 K in the magnetic fields up to 4 T. Squeezing effect of a current is recognized in all specimens, and anisotropy of the squeezing effect, which is induced by magnetic breakdown, is ob…
A new photocathode detector for surface-EXAFS was used to study oxide formation on the surface of polycrystalline Cu plates. The EXAFS spectra taken from the surface of these plates were compared to EXAFS spectra from Cu2O and CuO powder standards. The data demonstrate that Cu2O forms on the surface of Cu during the e…
The visual variations in brightness of R CrA, S CrA, T CrA, and R Mon, all classified as T Tau-like irregular variable stars, have been investigated. Long-period variations with time scales of approximately 1000-1500 days and 8000-10,000 days were found in these stars. These long-period variations are unlikely to be d…
Abstract Mineralogical properties of soils along a 500‐km north‐south transect in the mountainous Asir region were investigated. The transect represented areas of wide variations in climate, parent material, and topography. Soils developed on stable landscapes at higher elevation (> 2,000 m) have well‐developed pro…
Abstract Polyethylenproben unterschiedlicher Kristallinität und Vernetzung wurden zur Freilegung übermolekularer Strukturen plasmachemisch geätzt. Die elektronemikroskopischen Aufnahmen der geätzten Polymeroberflächen zeigten, daß sich Unterschiede im Kristallinitätsgrad bis zu 3% im Ätzrelief widerspiegeln.
Nickel, in low concentration, has been implanted in carbon foil. Both the Ni 2p3/2 and the L3M45M45 Auger levels are shifted 0.9 eV relative to nickel foil, while the valence band level is shifted by 1.2 eV. The characteristic energy loss peak associated with the core and valence levels of bulk nickel is observed on t…
Abstract The most susceptible site for pit initiation was found by optical metallography and transmission electron microscopy to be the retained delta ferrite/austenite interface. Microanalysis results, which were obtained with scanning transmisssion electron microscopy, virtually disprove the chromium depletion theor…
Abstract The small‐angle x‐ray scattering (SAXS) from an Epon 812 and two Epon 828 (one amine‐cured and one anhydride‐cured) epoxy resins has been measured using a Bonse‐Hart system. The data cover the angular range (2θ) between 20 sec and 60 min. After correction for absorption, background and vertical beam divergenc…
A short review is provided of the models used by earlier researchers to explain or predict tear re sistance of woven fabrics. Many such models emphasize either differential yam extension in the region of the tear or differential yarn slippage across the apex of the tear. A limited number of experi ments with selected…
Abstract The roles of pH and ionic strength on the structure and stability of collagen fibrils have been investigated by means of x‐ray and neutron diffraction techniques. High‐angle x‐ray diffraction shows that a salt concentration of 0.5 M KCl is sufficient to reduce the osmotic swelling and related disordering in t…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics and mechanism of the reaction of hydrogen peroxide with thiolato complexes of cobalt(III) and chromium(III). Comments on the nucleophilicity of coordinated sulfur and the stability of coordinated sulfenic acidsI. Kofi Adzamli and Edward DeutschCite this: Inorg. Chem…
Alumina and SiC can be recovered from clay by carbon reduction. Kinetic experiments showed that the solid‐solid reaction proceeds through gaseous intermediates of CO and SiO. By mixing part of the carbon with the clay and using the balance to form SiC, Al 2 O 3 and SiC were physically separated as products. This separ…
A wide variety of polymers and copolymers of 1,3-dienes have been modified at low temperatures via the ene reaction with 4-substituted l,2,4-triazoline-3,5-diones. The resulting modified polymers were characterized via infrared spectroscopy, nuclear magnetic resonance, intrinsic viscosity, gel-permeation chromatograph…
Silk proteins were solubilized from cocoons with ethylenediamine/cupric hydroxide solution. A series of polymers of the smallest component, detected by polyacrylamide-gel electrophoresis, could be converted into the smallest component by reduction and aminoethylation. Fibroin and sericin fractions were separated by pr…
Mn1-x-yAlxCyforms a ferromagnetic metastable tetragonal τ-phase in the composition range0.42 \leq x \leq 0.47and0 \leq y \leq 0.021. Its high unaxial magnetocrystalline anisotropy makes it an interesting candidate for a permanent magnet. In order to investigate the kinetics of the transformations which occur in this s…
Abstract The K fertilization requirement for corn ( Zea mays L.) frequently is overestimated by soil test procedures for Atlantic Coastal Plain soils having sandy Ap horizons and high K concentrations in clayey subsoil. It seemed probable that the lack of response could reflect availability of subsoil K. This field an…