Materials Literature
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A brief account is given of the theory of the vibrations of an imperfect crystal containing isolated impurities and pairs of impurities, and the strength of the induced infra-red absorption is discussed. An analysis is then made, by the methods of group theory, of the energy levels and expected optical transitions of…
Abstract The scattering patterns are calculated from anisotropic rods having an arbitrary angle of the polarizability axis with respect to the rod axis. The effect of a distribution of orientation of the rods is explored. This leads to a change in scattering patterns produced by orienting the rods upon stretching the…
Earlier work showed that some low-field magnetic properties of high-permeability Ni-Fe alloys containing about 80-percent Ni could be explained by considering the effect of the filling of the 3d vacancies of the Ni atoms by the outermost electrons of an added nonferromagnetic element. This work is extended to show how…
Single crystals of CdF2, doped with Eu3+, were grown by the Bridgman method, and shown by fluorescence and absorption spectra to contain no detectable Eu2+, irrespective of the presence of Na+ or Y3+ as added impurities. Ultraviolet irradiation at 77°K produced a new broad absorption band near 3400 Å, which disappeare…
Abstract The wavelength dependence of photodegradation of three “high temperature” aromatic polyamide polymers has been very accurately determined by means of a fast grating spectrograph used in conjunction with a high pressure xenon arc. One of these polymers, the poly‐(isophthalamide) of 4,4′‐bis( p ‐aminophenyl)‐2,…
Abstract Amputated hyperinnervated Anolis carolinensis limbs were studied histologically at various times from early stages of post‐amputational wound healing to formation of mature mounds. Comparable stages of normally innervated amputated limbs were also studied. The sequence of events involved in tissue repair was…
Abstract Diffusion of sulfur and MBTS across interfaces between dissimilar rubbers has been measured by microinterferometry. This technique involves the comparison of optical path length through refractive index gradients, due to diffusion, against that of a reference area. Differential diffusion coefficients are obta…
The Young's and shear moduli of polycrystalline yttrium oxide, holmium oxide, and erbium oxide were determined from room temperature to 1000°C using the sonic resonance technique. The bulk modulus and Poisson's ratio were computed as functions of temperature for each oxide. The Young's, shear, and bulk moduli decrease…
A greater percentage of mesquite seeds germinated and more vigorous seedlings were produced at a simulated soil temperature of 85 F than at 70 or 100 F. Alternating the temperature between 68 (16 hr) and 86 F (8 hr) did not increase the percentage germination as compared to constant 85 F. As temperature increased mois…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFluorinated iron phthalocyanineJohn Gareth Jones and M. V. TwiggCite this: Inorg. Chem. 1969, 8, 9, 2018–2019Publication Date (Print):September 1, 1969Publication History Published online1 May 2002Published inissue 1 September 1969https://pubs.acs.org/doi/10.1021/ic50079a045…
The freshwater ostracode Candona rawsoni Tressler can survive in a torpid state. The time required for rejuvenation of the torpid ostracode depends upon the temperature of the water and the soil-moisture content.
K2WO4 crystallizes in space group C2/m with the axes a 12.39, b 6.105, c 7.560 A., and b 115.96 Deg. The 4 formula units per unit cell form layers parallel to (001), in which each WO4 tetrahedron is surrounded by an almost regular hexagon of K ions. The W-O bond length is 1.79 A., and the K-O and O-O distances are in…
Optical activity has been observed for the first time in a crystal of the non-enantiomorphous class \bar 4 CdGa2S4 is optically isotropic at 4872 Å (20°C) and this allows observation of optical rotation for propagation in directions away from the c axis. The magnitude of the optical rotatory power is 17.3 deg.mm−1 alo…
Abstract In der BASF wird Formaldehyd durch oxidative Dehydrierung von Methanol an einem Silberkristall‐Katalysator bei 600 bis 700°C erzeugt. Die Temperatur wird durch Regelung der Luftzufuhr eingestellt und ist für den maximalen Umsatz ebenso wichtig wie die Korngröße des Katalysators. Es wird über die optimale Kata…
The properties of strontium-doped lanthanum chromite (La 0·84 Sr 0·16 CrO 3 ) are discussed, with particular attention to its application as an electrode material for MHD power generation. The influence of firing temperature on the ceramic properties and the behaviour of strontium carbonate as a sintering agent are de…
The structure of hardystonite, Ca2ZnSi207, was refined to R = 5.30/0 from three-dimensional diffractometer data. The Zn-O and Si-O bonds are predominantly covalent, and the adjacent covalent sheets of [ZnSi207 ]4- are linked by Ca2+ ions, with the interlayer bonding being predominantly ionic in character.
Abstract Organische Reaktionssysteme mit sehr kleiner elektrolytischer Leitfähigkeit können in neuartigen Elektrolysezellen, die nach dem „Prinzip des kleinsten Elektrodenabstands”︁ konstruiert worden sind, unter technisch interessanten Strom/Spannungs‐Bedingungen umgesetzt werden. Für diaphragmenlose Elektrolysen wer…
The filtering rates of Calanus helgolandicus were measured on synchronously growing populations of the diatom Ditylum brightwellii, by following changes in cell numbers and also by measuring the ingestion of 14 C labeled cells at selected intervals during 2‐day periods. The growth of the diatoms was adjusted to be one…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrganometallic pnicogen complexes. III. Preparation and structural characterization of the triarsenic-cobalt atom cluster system As3Co(CO)3. The first known X3-transition metal analog of group VA tetrahedral X4 moleculesAlan S. Foust, Michael S. Foster, and Lawrence F. DahlC…
Auszug Die KristaIIstruktur von Fresnoit, Ba2(TiO)Si207, wurde aus der PattersonProjektion P(uv) bestimmt und nach der Methode der kleinsten Quadrate aus hkl-Interferenzen verfeinert. Eigentfunlich fur die Struktur ist die tetragonalpyramidale Umgebung des Titans. Schichten aus heterozyklischen Hinfgliedrigen Ringen,…