Materials Literature
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Abstract First, explicit expressions are obtained for the state of stress and deformation due to a periodic distribution of dislocations with respect to three-dimensional space and time. Further, equilibrium conditions for continuously distributed dislocations are derived from the law of energy conservation. The condi…
The ${\mathrm{Mn}}^{55}$ nuclear magnetic resonance has been studied in Mn${\mathrm{Fe}}_{2}$${\mathrm{O}}_{4}$. The unpulled resonance frequency extrapolated to 0\ifmmode^\circ\else\textdegree\fi{}K is 587 Mc/sec. By studying the effect of an external magnetic field on the resonance it was determined that the main li…
The relative dielectric constant of a series of perovskites such as CaTi${\mathrm{O}}_{3}$, SrTi${\mathrm{O}}_{3}$, BaTi${\mathrm{O}}_{3}$, PbTi${\mathrm{O}}_{3}$, and KTa${\mathrm{O}}_{3}$ has been measured at microwave frequencies over a wide range above the Curie temperature. It was found that a Curie-Weiss law of…
The deformation method is fundamental of the problems of buckling, bending, and simultaneous bending and compression or tension of elastic structures, such as continuous beams, frames, arches, etc. The derivation of the slope-deflection equations of the deformation method and the application of this method in solving…
Abstract Die Dunkelfärbung des frisch hergestellten, hellen Graphitoxids bei Lichteinwirkung beruht auf einer Zersetzung. Schon bei 20°C werden CO und CO 2 entwickelt.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotosensitized cis—trans Isomerization of Methyl OleateA. C. TestaCite this: J. Org. Chem. 1964, 29, 8, 2461–2462Publication Date (Print):August 1, 1964Publication History Published online1 May 2002Published inissue 1 August 1964https://pubs.acs.org/doi/10.1021/jo01031a516h…
The lattice constants and space groups of the selenates of Mg, Mn, Co, and Cu were determined. These selenates all crystallize with the ZnSO 4 structure. Above 40 kilobars and 400°C they all undergo a quenchable transition to the NiSO 4 structure.
Crystallographic analyses of dislocations and dislocation loops in deformed b.c.c. iron observed in the electron microscope have been carried out by applying the electron diffraction theory of contrast at dislocations. Dislocations in deformed iron are in the form of tangles, with interspersed clusters of dislocation…
SrBeO4.4HeO forms
The thermal decomposition of europium hydroxide in an air atmosphere was investigated by means of weight‐loss measurements, infrared spectroscopy, X‐ray diffraction analysis, and electron microscopy. These studies showed that EU(OH)° decomposed at temperatures between 225° and 300°C into EuOOH, which was stable up to…
The consequences of ]-refinement procedures on atoms whose charge distributions are intrinsically non-centrosymmetric are examined in terms of a simple hypothetical structure consisting of two sp a hybrid valence 'prepared' state nitrogen atoms which are centrosymmetrically disposed in a unit cell and asstuned to be v…
Optical absorption and thermoluminescence measurements on untreated crystals of magnesium oxide have shown that the crystals can be divided into two groups. X irradiation of the crystals induces an optical absorption peak at 2.3 ev in group I crystals and at 2.3 and 3.0 ev in group II crystals. Thermoluminescence curv…
The temperature dependence of breakdown field, distribution of time lag. and dielectric constant in high electric field were studied on polycrystalline BaTiO 3 . The d. c. breakdown field is nearly constant in the temperature range 20 to 150°C, on the other band the pulse breakdown field changes markedly near the Curi…
This paper is composed of three parts: 1 Apparatus and method for determination of heat transfer through fabric during flame contact; 2 experimental validation of mathematical analysis and heat flow; 3 application to determination of thermal properties of materials in thin layers.
A phase diagram of the system MnSi-Si containing Si in the range from 45.00 to 57.00 wt% is determined by the methods of X-ray, metallographic and thermal analyses and also by the electrical measurements. It is found that the intermetallic compound in this system is MnSi 1.72 . This compound has the maximum melting po…
Thermal expansion, ultrasonic and creep behavior of polytetrafluoroethylene are studied in temperatures from -100° to 180°C. The glass transition and primary dispersion of this polymer observed. The assignments of relaxations and transitions described in what follows are found to be quite compatible with experimental…
The various components of the stress-fields of piled-up groups of screw and edge dislocations are calculated by replacing the array of discrete dislocations by a continuous distribution. The stress-fields are resolved onto each of the eleven secondary systems of the face-centred cubic lattice; by mapping out the stres…
Intergranular cracking tendencies of fourteen stainless steels and two high-nickel alloys have been evaluated by exposing numerous specimens to polythionic acid and standard acid copper sulfate solutions. The sensitization curves for solution-annealed wrought stainless steels, which had been held for varying times at…
Crystals, needles, ribbons, and platelets, grown from pure and impurity-added CdS vapor, have been studied morphologically. Needles grow parallel to the [0001], [101̄0], and [21̄1̄0] axes of the hexagonal system. Ribbons grow parallel to the [101̄0] and [21̄1̄0] axes and their surfaces are parallel to the (12̄10) and…
The stress fields of edge dislocation dipoles are able to trap other edge dislocations that pass nearby. The configurations, energies, and trapping stresses of the resulting tripoles are discussed here in some detail. Dipoles may also interact dynamically with approaching dislocations because they cause fluctuating st…