Materials Literature
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The bipolar output of the rf phase detector of the receiver in a nuclear magnetic resonance pulse experiment is fed through a 4-diode sampling switch to an RC integrator, whose output is read by a recording electrometer. The switch (a ``transmission gate'') includes two type 7266 ceramic thermionic diodes, whose back…
Abstract Vanadinhexacarbonyl erweist sich als besonders reaktionsfähig. Reaktionen mit N‐Basen (B) in Benzol verlaufen bereits bei Raumtemperatur im Sinne einer „Basenreaktion”︁ unter Bildung von Hexacarbonylvanadaten, [VBn] [V(CO)6]2 (n = 4 oder 6). Auch schwache Basen wie Säurenitrile und O‐Basen geben Verbindungen…
In a hydrogen atmosphere, MgO was vaporized by heating MgO (periclase) in the range 1500° to 1900° C, and the vapor products diffused into Al 2 O 3 (sapphire) to form a uniform outer layer of spinel on all surfaces. At 1900°C. a spinel layer 48 mils thick could be obtained in 16 hours. The rates of spinel formation we…
The synthesis (as opposed to analysis) of multilayer dielectric films as antireflection coatings over any specified frequency band has not been attempted before. The similarity with transmission lines, which can be synthesized as multisection quarter-wave transformers to minimize reflection over any prescribed frequen…
Landells and Whewell have previously reported that vinyl monomers are polymerized “within viscose filaments” by hydrogen peroxide in the presence of ferrous salts and the polymers are not extractable. Such products, obtained by polymerization of acrylonitrile and styrene in viscose, have now been acetylated. Fractiona…
Cell wall preparations from the leaves of Eucalyptus globulus Labill. may absorb water equal to approximately 150% of their dry weight.
Abstract Carbon black, the most important reinforcing filler for rubber, must be well dispersed if it is to function effectively. The state of dispersion of the carbon black can be studied effectively by microscopic examination of a thin (2µ) section of the rubber compound, using transmitted light, as described by Tid…
The previously made absorption-band assignment (1) for the C=S stretching mode in xanthate-type compounds, 1020–1070 cm −1 , has been confirmed by the characteristic behavior of the C=S dipole in a range of different solvents (Bellamy and Rogasch (2)).
The technique of decorating dislocations was employed to investigate plastic deformation and fracture resulting from precipitation of H in Fe3% Si single crystals. It is shown that cracks are produced on (100) planes inside crystals quenched from H atmosphere at elevated temperatures or cathodically charged with H at…
Dense self-bonded silicon carbide, prepared by impregnating with silicon pressed mixtures of silicon carbide and graphite, has been improved by attention to grading and composition. Treatment at 2000°C for ½ h has given a much greater degree of self-bonding. Porous self-bonded silicon carbide with a dense surface has…
The diamagnetic susceptibilities of some pyrolytic graphites deposited at 2100-2300\ifmmode^\circ\else\textdegree\fi{}C have been measured at room temperature. As-deposited samples had significantly larger susceptibilities than that of well-graphitized carbons or single-crystal graphite. Heat treatment at temperatures…
Based on conductivity, Hall effect, and magnetoresistance measurements an attempt is made to describe the behavior of current carriers in the layer planes of well-ordered pyrolytic graphite. The total carrier concentration decreases from approximately 11\ifmmode\times\else\texttimes\fi{}${10}^{18}$ ${\mathrm{cm}}^{\en…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUNUSUAL MAGNETIC PROPERTIES OF SOME SIX-COÖRDINATE COBALT(II) COMPLEXES1 —ELECTRONIC ISOMERSR. Carl Stoufer, Daryle H. Busch, and Wayne B. HadleyCite this: J. Am. Chem. Soc. 1961, 83, 17, 3732–3734Publication Date (Print):September 1, 1961Publication History Published online…
As part of a study of fabric drape, the fabric-shearing apparatus due to Mörner and Eeg-Olofsson has been built and studied. Methods of expressing the results are given and the variability of the results has been measured. The effect of tension on the specimen has been measured and a model is given which may be used t…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Crystal and Molecular Structure of S6 (Sulfur-6)Jerry Donohue, Aimery Caron, and Elihu GoldishCite this: J. Am. Chem. Soc. 1961, 83, 18, 3748–3751Publication Date (Print):September 1, 1961Publication History Published online1 May 2002Published inissue 1 September 1961htt…
The specimen independent infra-red absorption spectrum of diamond in the 2 μ to 6 μ region has been examined using a grating spectrometer. The results have been analysed in terms of multi-phonon processes. In particular the two-phonon absorption has been examined in detail in an attempt to deduce phonon energies for t…
A method is described for preparing silicon nitride bodies of almost theoretical density. Silicon nitride powder is hot pressed with a small proportion of catalyst, preferably magnesium oxide or nitride, at 1850°C. The bodies have very high flexural strength up to high temperatures, and preliminary measurements of cre…
The effect of hydrostatic pressure on the energy gap of Bi2Te3 has been investigated in the pressure range one to 30 000 atm. From resistivity measurements as a function of temperature and pressure, it has been determined that the energy gap decreases from 0.171 ev at one atmosphere to 0.104 ev at 30 000 atm, correspo…
A careful consideration on lattice vibrations in the ionic ferroelectric crystals such as BaTiO 3 reveals that a correct physical picture of the ferroelectric transition in these crystals may rather be regarded as an order-disorder transition of orientation of dipoles. A strong local order in the disordered phase is a…
Torsional modulus–temperature data have been obtained on heterogeneous polymer compositions prepared by several procedures. Both the state of aggregation of the component chain molecules and their degree of compatibility are significant variables. Modulus curves similar to those for crystalline polymers can be obtaine…