Materials Literature
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Raman spectra of water solutions of NaH2PO2, KH2PO2, HPO3, NaPO3, K4P2O7, K2Na2P2O7, K2H2P2O7, and Na2H2P2O7 were photographed using a Hilger constant-deviation spectrograph. Illumination was provided by four Hanovia mercury lamps, the 4358A line being used as the exciting radiation. A system of liquid filters reduced…
The diatom flora inhabiting the muddy shores and bottoms off Plymouth has received little attention in comparison with the fauna associated with such muds. Since a large number of the microfauna depend, to a great extent, upon the diatoms as a source of food (Mare, 1942), a knowledge of the latter is there-fore desira…
The low temperatures produced by the adiabatic demagnetization of a paramagnetic salt have been used to cool specimens of aluminium, cadmium, gallium and zinc, and their critical fields have been measured down to 0·1° K. The magnetic measurements on the metal and the salt were made independently and the experimental a…
1. A sand-dwelling population of the diatom Hantzschia amphioxys Ehrb. is described, which exhibits a tidal rhythm that persists for sonic days when held without tide under artificial conditions in the laboratory. This rhythm is characterized by a periodic inversion of the phototropistic response, and by an agglutinat…
Abstract 1. In Fortsetzung unserer Untersuchungen über Thio‐ 2 ) und Selenohalogenide 3 ) des dreiwertigen Antimons und Wismuts wurden folgende Tellurohalogenide durch gemeinsames Tempern von Tellurid und Halogenid unter Luftabschluß dargestellt: SbTeJ, BiTeBr und BiTeJ. SbTeJ kristallisiert in rhombischen Nadeln mit…
A general method is developed for a rigorous estimation to upper and lower bounds of scattering phases in the variational methods applied to one-dimensional problems. It is also possible to estimate the mean error of the approximate wave function itself. An essential point in the method is the evaluation of mean squar…
Absolute rate theory is combined with molecular models in the study of the annealing of metals and of glass. It is thus possible to obtain expressions which are in close agreement with experimental data. Both the observed first-order data for metals and the second-order data for glass are predicted in this way. A virt…
In Part I the subjective evaluation of stiffness is used as a standard with which to compare the results obtained from five laboratory methods of measuring stiffness. Measurements were made on a range of nineteen fabrics of varying fiber content, weave, and weight. The results indicated significant correlation in four…
It will be pointed out that the anisotropy energy is of primary importance in the theory of antiferromagnetism. The formula for the susceptibility χ= (χ∥ + 2χ⊥)/3, which follows in van Vleck's theory from a rather arbitrary assumption that the parallel and perpendicular domains are distributed with a ratio 1:2, can on…
An investigation of the diffusion of ions in several glasses was made using radioactive tracer techniques. The resulting diffusion curves were analyzed to obtain the thermodynamic properties of the diffusion process. These properties are indicative of energy and structure changes in the glass networks. Interpretations…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAmmonia Decomposition and Related Phenomena on Rhenium Catalysts1James Peter McGeer and Hugh S. TaylorCite this: J. Am. Chem. Soc. 1951, 73, 6, 2743–2751Publication Date (Print):June 1, 1951Publication History Published online1 May 2002Published inissue 1 June 1951https://pu…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfluence of Molecular Weight on the Properties of PolystyreneE. J. Merz, L. E. Nielsen, and Rolf BuchdahlCite this: Ind. Eng. Chem. 1951, 43, 6, 1396–1401Publication Date (Print):June 1, 1951Publication History Published online1 May 2002Published inissue 1 June 1951https://…
The following paper deals with evidence of ferroelectricity in KNb${\mathrm{O}}_{3}$ and NaNb${\mathrm{O}}_{3}$. Temperatures at which both materials undergo crystallographic changes and corresponding changes in dielectric constant and loss tangent are reported. Photographs of dielectric hysteresis loops and values of…
Abstract The theory of propagation of longitudinal waves of plastic deformation is extended to apply to materials in which the stress is a function of the instantaneous plastic strain and strain rate. Solutions are given for an idealized flow law and compared with solutions based upon earlier theories which neglect st…
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Summary The principal difficulty in developing a dislocation theory of mechanical twinning has been to explain how a twin grows through a finite thickness of crystal. By extending the recent theory of slip bands, proposed by Frank and Read, it is possible to show that a dislocation can move steadily from plane to plan…
An antiferroelectric state is defined as one in which lines of ions in the crystal are spontaneously polarized, but with neighboring lines polarized in antiparallel directions. In simple cubic lattices the antiferroelectric state is likely to be more stable than the ferroelectric state. The dielectric constant above a…
In this experiment the gyromagnetic ratio of a sample of very pure iron was determined. The sample was wound with a magnetizing coil and supported as a torsional pendulum in an evacuated space almost completely free of residual magnetic fields. Changes in pendulum amplitude were brought about by repeated and synchroni…
In the vicinity of an edge type dislocation, the density of electrons, and therefore the width of the filled portion of the conduction band is not uniform. To keep the electrons in equilibrium, an electrostatic potential is required. The scattering caused by this potential is used to calculate the increased resistance…
Among the problems introduced by swept wings is that of the non‐rectangular panel in equilibrium under loading applied tangentially along its edges. The present article examines the state of stress in a general uniform quadrilateral panel and, for the benefit of stiffness calculations, the strain energy stored in it.…