Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Spontaneous-emission probabilities for electric- and magnetic-dipole transitions from excited electronic states of ${\mathrm{Pr}}^{3+}$, ${\mathrm{Nd}}^{3+}$, ${\mathrm{Eu}}^{3+}$, ${\mathrm{Er}}^{3+}$, and ${\mathrm{Tm}}^{3+}$ impurities in ${\mathrm{Y}}_{2}$${\mathrm{O}}_{3}$ are calculated using eigenstates in inte…
We report the first clear evidence that rf magnetic fields generate acoustical side-bands in the M\"ossbauer spectra of metallic ${\mathrm{Fe}}^{57}$. We advance an explanation of this magnetoacoustic effect in terms of magnetostriction, and suggest that this effect provides a consistent explanation of the results of…
Measurements of electron-capture cross sections ${\ensuremath{\sigma}}_{10}$ and electron-loss cross sections ${\ensuremath{\sigma}}_{01}$ for protons and atomic hydrogen in ${\mathrm{H}}_{2}$, He, Ar, Kr, ${\mathrm{N}}_{2}$, ${\mathrm{O}}_{2}$, CO, C${\mathrm{O}}_{2}$, ${\mathrm{H}}_{2}$O, C${\mathrm{H}}_{4}$, ${\mat…
Abstract Evaluations of cyclic iminocarbodithioates as accelerators and vulcanizing agents are described. The starting amines include morpholine and 3-azabicyclo-[3.2.2]nonane and vary in ring size from tetra- to octamethylenimine. The chemical structure of these compounds is correlated with their cure characteristics…
The photolysis of polyvinylpyrrolidone in oxygen-free aqueous solutions has been investigated as a function of polymer concentration, chain length, light intensity, and temperature. Ultraviolet spectra at various degrees of degradation have been measured. The experimental data can be satisfactorily accounted for by a…
Abstract Nitroalkyl acrylates and methacrylates involving some new compounds were prepared. The homopolymerization of these monomers in toluene and their copolymerization with styrene in acetone were carried out with azobisisobutyronitrile as initiator. The rate of polymerization of the nitroalkyl acrylates showed a c…
Abstract The surface conductivity of salt free montmorillonite clay gels saturated with lithium, sodium, potassium and cesium has been studied. The theory of the behavior of heterogeneous dielectrics adapted to systems having a surface charge density has been applied to the clay gels. From numerical calculations it be…
Abstract The dissolution of hectorite suspensions in M/20 CaCl 2 has been studied under conditions of low acidity. The reaction was almost completed within 2 weeks but very slow changes continued. There was an initial preferential release of Mg which corresponded approximately to the number of Mg atoms exposed at the…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolyoxamides. 1. Preparation and Characterization of Cyclic OxamidesO. Vogl and A. C. KnightCite this: Macromolecules 1968, 1, 4, 311–315Publication Date (Print):July 1, 1968Publication History Published online1 May 2002Published inissue 1 July 1968https://pubs.acs.org/doi/1…
Abstract Dithioamines and sulfenamides derived from various cyclic amines were evaluated as accelerators and vulcanizing agents. Structural variations of these compounds are correlated with their scorch delaying properties, accelerating activity and vulcanization efficiency, employing the Mooney Viscometer and the Mon…
Drawn and undrawn nylon 66 filaments were exposed to oxygenated aqueous systems, and the extent of chemical degradation was studied as a function of time. Degradation was estimated by measuring the changes in both chemical and physical properties. At the same time, oxygen absorption measurements were made and these we…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolyoxamides. II. Polymerization of Cyclic DiamidesO. Vogl and A. C. KnightCite this: Macromolecules 1968, 1, 4, 315–318Publication Date (Print):July 1, 1968Publication History Published online1 May 2002Published inissue 1 July 1968https://pubs.acs.org/doi/10.1021/ma60004a00…
Abstract Temperature dependence of dielectric loss, mechancial loss, and dynamic modulus were measured to study polymer blending. Results were as follows: Dielectric loss and dynamic modulus of NR—BR blends showed two peaks corresponding to NR and BR, indicating that the blends were microheterogeneous. A single, broad…
A literature survey on thermal stresses during welding and buckling after welding is described. From the analyses found, a computer program was developed to calculate thermal stresses and resulting residual stresses due to a moving heat source. This program is included in the appendix. Studies at Marshall Space Flight…
The infrared absorption spectra of the four zinc halides have been investigated by the low-temperature matrix-isolation technique. The spectral range 800–35 cm−1 has been covered. Four absorption regions have been observed in all cases. The highest energy region is structured and represents the antisymmetric stretchin…
The input admittance of a circular waveguide opening onto an infinite flange with a homogeneous lossy dielectric coating is derived using integral transforms and assuming the dominant TE11mode as the trial field at the aperture. Admittance calculations for low-loss dielectric sheets of various thicknesses are given an…
The structure of aluminum chloride hexahydrate, A1C13.6H20, has been studied with X-ray and neutron diffraction techniques. Precise values for the dimensions of the hexagonal unit cell have been obtained: a= 11-827 + 0.006, c= 11.895 + 0.003/~. Single-crystal X-ray data have been used to confirm the space group, R3c,…
The transition region analysis of an abrupt heterojunction is extended to include the effects of mobile carriers‘ charge in the space charge regions. Deviations from the depletion model are obtained when the wide band-gap semiconductor is heavier-doped-This is due to a non-negligible potential drop across the narrow b…
Measurements have been made of the recoilless fraction and broadening of Mössbauer γ rays Rayleigh scattered from glycerol and sec-butyl benzene in the supercooled liquid, glassy and polycrystalline states, and from polycrystalline benzene. It is concluded that the vibration amplitude (possibly rotational in origin) i…
The bending behaviour of square plain-weave fabrics spun and woven from nineteen different fibres, each in a range of cover factors, has been studied. It is shown how this behaviour is determined by the mechanical properties of the fibre and the frictional and geometrical restraints within and between yams in the fabr…