Materials Literature
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Structural and metallographic studies were carried out on the Nd-Fe-B alloy system as well as the Nd-Fe-B tetragonal compound on which record high energy magnets have been developed using a powder metallurgical technique. The study on the new magnet has also been extended to other R-Fe-B componds containing various ra…
An equation for a nonlinear calibration curve of volume fraction vs integrated intensity ratio is presented for monoclinic‐stabilized cubic ZrO 2 systems containing YO 1.5 , CaO, and MgO. A parameter in the equation was evaluated theoretically and is given for a range of cubic solid solution compositions.
Abstract Nonlinear optical properties are a sensitive probe of the electronic and solid‐state structure of organic compounds and as a consequence find various applications in many areas of optoelectronics including optical communications, laser scanning and control functions, and integrated optics technology. Because…
Radiation from a Q-switched YAG laser, focused on the (100) face of a single crystal diamond anvil in a high-pressure diamond cell, caused a portion of the diamond anvil face to melt. Potassium bromide mixed with graphite was under pressure between the anvils when melting occurred. The diamond surface melted at pressu…
High-resolution carbon-13 nuclear magnetic resonance (NMR) spectra of enzyme-inhibitor and enzyme-substrate complexes provide detailed structural and stereochemical information on the mechanism of enzyme action. The proteases trypsin and papain are shown to form tetrahedrally coordinated complexes and acyl derivatives…
Delocalization of excitation in a system of disordered but uniformly distributed centers, its quenching by alien admixtures, and self-quenching by cross relaxation by pairs of identical particles are considered. It is shown that the direct transfer of excitation from an initial center to its neighbors becomes sequenti…
Materials representing common interstratified clay minerals are shown to be composed of aggregates of fundamental particles. Transmission electron microscopy and x-ray diffraction demonstrate that the x-ray diffraction characteristics of a wide range of interstratification can be modeled experimentally by utilizing ma…
All the different crystalline (brittle (II), glassy (I g ), plastic stable (I) and metastable (I')) phases of 1-cyanoadamantane: C 10 H 15 CN are characterised by differential scanning calorimetry studies. The transition temperatures and their respective enthalpies are determined I g -I' (170K), II to I (280K, 5.5 kJ…
Silicones and fluorosilicones have traditionally been classified as high performance materials due to their suitability for use under extreme conditions and their processability has been particularly interesting as a result of the very flexible siloxane chain. The present paper discusses selected examples where more r…
Neon, argon, and xenon bubbles in aluminum have been investigated by means of electron-energy-loss spectroscopy and transmission electron microscopy. The density and pressure in the bubbles were determined from the pressure shift of the $^{1}S_{0}\ensuremath{-}^{1}P_{1}$ transition of the rare gases as well as from an…
A one‐step synthesis of a new sulfur‐containing compound, L‐α‐amino‐β‐thio‐ϵ‐caprolactam from L‐cysteine methyl ester and 2‐chloroethylamine has been described. This intramolecular cyclic amide of S ‐(β‐aminoethyl)‐L‐cysteine serves as a good substrate for α‐amino‐ϵ‐caprolactam racemase. L‐α‐Amino‐β‐thio‐ϵ‐caprolactam…
The authors have measured the low-temperature thermal conductivity of unusual geometry sapphire bars that have undergone various surface treatments. They show that after careful surface polishing a ten-fold enhancement over the correctly calculated Casimir limit is possible, and that the phonon specular reflection coe…
Intrinsic paramagnetic defects have been detected by ESR measurements in tetrathiafulvalene -$p$- chloranil single crystals, associated with the neutral-to-ionic phase transition at ${T}_{c}=84$ K. Two kinds of paramagnetic species are identified with delocalized spins propagating on either donor or acceptor sites. To…
The active site of the aspartic proteinase, endothiapepsin, has been defined by X-ray analysis and restrained least-squares refinement at 2.1 A resolution with a crystallographic agreement value of 0.16. The environments of the two catalytically important aspartyl groups are remarkably similar and the contributions of…
Electrical conductivity and thermoelectric power are measured in the temperature range 30 to 700 °C on iron-nickel mixed oxide samples containing upto 5 mol% NiO, sintered at different temperatures (1050 t o 1300 °C). The plot of log σ vs. 1/T always shows two straight lines, the slope of the higher temperature region…
UV optical absorption and IR transmittance of Czochralski grown Gd3Ga5O12, garnet single crystals are investigated. Transitions of Gd3 from the 8S7/2 ground state to the 6P, 6L and 6D states are detected. With increasing Ca content a broad band at 29400 cm−l is observed. In the IR spectra the shift of the absorption e…
We have studied the magneto-optical properties of the ${\mathrm{Ga}}_{x}{\mathrm{In}}_{1\ensuremath{-}x}\mathrm{Se}$ system in the indium-rich and gallium-rich regions near the fundamental band gap by wavelength-modulation spectroscopy at 10 K with the electric vector $\stackrel{\ensuremath{\rightarrow}}{\mathrm{E}}$…
Two general types of energy-dependent cross-section variations are demonstrated for inverse photoemission: (i) an atomic effect based on the spatial extent of the wave function and (ii) a solidstate effect caused by peaks in the Fourier spectrum of bandlike states. As examples, data are shown on the photon-energy depe…
The Rayleigh–Brillouin spectrum of 2,4-dimethyl pentane, 2,4,6-trimethyl heptane, 3,5-dimethyl heptane, 2,2,4,4-tetramethyl pentane, and 2,2,4,4,6,6,8,8-octamethyl nonane was measured as a function of temperature from well above the Brillouin linewidth maximum down to the glass transition region. Brillouin splittings…
We report on high-resolution total-yield measurements of the Cu ${L}_{2,3}$ absorption edge in ${\mathrm{Cu}}_{2}$O using the JUMBO monochromator at the Stanford Synchrotron Radiation Laboratory. Care was taken to prepare the surface of a well-characterized single crystal, rather than use oxidized copper. A comparison…