Materials Literature
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Results are presented for a theoretical and experimental investigation of magnetic platelets introduced into a nematic liquid crystal. The equilibrium positions of the platelets and nematic director as a function of applied field are calculated and compared with experiment.
The effect of quenching and tempering structure of various carbon steels on the diffusivity and solubility of hydrogen were studied at room temperature by using an electrochemical permeation technique. The minimum diffusion coefficient is obtained when the steels are in the as-quenched state; i.e, in a martensitic str…
Emission spectra have been recorded of polycrystalline samples of Na7EuIIIW10O35·xH2O and K13EuIII(SiW11O39)2·xH2O. The fluorescence of the europium ion can be efficiently pumped via the internal states of the tungstate groups. The cluster maintains its integrity in neutral aqueous solution, in which the europium ion…
SrTiO3 crystals have been prepared by flame-fusion growth and from KF-LiF and K-Li-borate fluxes. The crystals are characterized by EPR, absorption spectra, chemical analyses and 7-rocking curves, and the structural perfection of flame-fusion and flux-grown crystals is compared.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNitric oxide complexes of manganese and chromium tetraphenylporphyrinB. B. Wayland, L. W. Olson, and Z. U. SiddiquiCite this: J. Am. Chem. Soc. 1976, 98, 1, 94–98Publication Date (Print):January 1, 1976Publication History Published online1 May 2002Published inissue 1 January…
An orthogonality relation for the Rayleigh-Lamb modes of vibration of an isotropic, homogeneous, elastic plate is derived. Subject Classification: [43]40.24.
Thin‐film solid‐state galvanic cells were fabricated using Pb metal as anode, as electrolyte, and as cathode. Because of the high resistivity of , it was codeposited with to form a more conductive mixed cathode layer. Such cells developed open‐circuit voltages from 0.61 to 0.70V, compared to 0.70V theoretical. Cells w…
A survey, comparison, and critical analysis is presented of data compiled from the scientific literature concerning diffusion in copper alloy systems involving elements in Group VII (Co, Fe, Ni, Pd, Pt, Rh, Ru). Here the term ’’copper alloy system’’ is interpreted in the broadest sense. For example, the review of diff…
X-ray diffraction photographs of protein single crystals have been obtained using synchrotron radiation produced by an electron-positron storage ring. The diffracted intensities observed with this unconventional source are a factor of at least 60 greater than those obtained with a sealed x-ray tube using the same crys…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHard Block Length Distribution in Segmented Block CopolymersL. H. Peebles Jr.Cite this: Macromolecules 1976, 9, 1, 58–61Publication Date (Print):January 1, 1976Publication History Published online1 May 2002Published inissue 1 January 1976https://pubs.acs.org/doi/10.1021/ma60…
The α—β transition in the cristobalite phases of SiO2 and AlPO4 has been studied using X-ray powder diffraction. The transitions show marked hysteresis but also occur over a range of about 20°C in which the α and β phases coexist. The lattice parameters show a smooth and slow variation with temperature for each phase…
The Stokes’ flow problem is considered for micropolar fluids in which the obstacle has an axis of symmetry, and the flow at distant points is uniform and parallel to this axis. A general expression for the drag is derived by using the arguments involving an axisymmetric point force and application is illustrated for t…
The strength of BaTiO 3 which had been hot‐pressed to ∼99% of theoretical density and tested above the Curie temperature was—9000 psi greater than at room temperature. This measured difference in strength is attributed to internal stress from the cubic→tetragonal phase transformation. Correction of measured strength t…
Abstract —Direct photooxidation of cyanine dyes was found to be markedly enhanced by formation of hypsochromically shifted (H) aggregates. Singlet oxygen was found to attack many cyanines possessing low oxidation potentials with rate constants in excess of 10 8 t mol ‐1 s ‐1 . Singlet oxygen attack on 3,3′‐diethyl‐8,1…
Phase equi ibria in the system MgO‐MgC 2 ‐H 2 O at 2°±3°C were determined and the reactions by which the equi ibrium phases, 5Mg(OH) 2 MgC 2 8H 2 O and 3Mg(OH) 2 MgC 2 8H 2 O, deve op were studied by X‐ray diffractometry. As reactive MgO is disso ved by magnesium ch oride so utions, a thixotropic suspension is convert…
Dianin's compound, suitably agitated, has been shown to sorb freely Ar, Kr, Xe, CO2, CH4, C2H6, C3H8, n-C4H10, iso-C4H10, and neo-C5H12, and behaves in some respects like an organic zeolite; the numbers of molecules filling each cavity in the host lattice varied from 6 for Ar (–196 °C) and CH4(–183°C) to 2 for iso-C4H…
Thermodynamical properties of an order-disorder model of ferroelectrics proposed by Comes, Lambert, and Guinier for the perovskites BaTi${\mathrm{O}}_{3}$ and KNb${\mathrm{O}}_{3}$, are discussed. It is shown that in the absence of crystalline distortion induced by the motion of the tunneling ion, the only stable orde…
We have measured as functions of temperature the refractive indices and linear birefringence of seven homologous compounds of p, [pacute]-di-n-alkoxy-azoxybenzenes in the nematic phase. Using the Vuks' model of local-field correction, we have deduced from our results both the microscopic and the macroscopic order para…
Corrosion of a 20Na2O‐10CaO‐70SiO 2 (mol%) glass by water was investigated using ir reflection spectroscopy, solution analysis, electron microprobe, and Auger electron spectroscopy. Corrosion proceeds at a much slower rate in the ternary glass than in a 20Na2O‐80SiO2 glass. Within the Na‐depleted layer of the ternary…
The theory of characteristic electron energy losses is discussed in terms of the electronic band structure of a solid. The relationship between the observed plasmon energies, the average interband energy gap and the background dielectric constant of the solid is developed. The transmission energy loss spectra of a num…