Materials Literature
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The compressive creep of carbides having the composition U 0.79 Pu 0.21 C 1.02 and a sintered density of 11.8 g/cm 3 was studied at 1300°, 1400°, and 1500°C and stresses of 2000, 4000, and 6000 psi. The equation which best fitted the data was The dominant creep mechanism was probably grain‐boundary sliding. The hardne…
A neutron diffraction study on the powder samples of FeMnP has been made in order to determine the magnetic structure as well as the ordering of iron and manganese atoms. It is ascertained that iron and manganese atoms occupy the tetrahedral and pyramidal sites, respectively. FeMnP is antiferromagnetic with the Néel t…
Abstract Choline kinase was purified approximately 300-fold, in 5% yield, from an autolysate of dried brewers' yeast. A molecular weight of 67,000 was estimated using a Stokes radius of 33 A, as determined by Sephadex G-200 chromatography. An s20,w of 4.8 S was obtained by sucrose density gradient centrifugation. Enzy…
The heat capacity of ${\mathrm{V}}_{2}$${\mathrm{O}}_{3}$ has been measured between 0.3 and 10 K at pressures of 1 and 25 kbar. The results confirm that the very high electronic heat capacities measured for doped samples are characteristic of pure ${\mathrm{V}}_{2}$${\mathrm{O}}_{3}$ in the metallic phase.
Abstract Amorphous thin films of tellurium have been prepared by condensation on the substrate at liquid helium or nitrogen temperature in high vacuum, and a transmission electron diffraction study of these films has been undertaken. Diffraction patterns of such films show diffuse halos, which are characteristic of a…
Existing formulations for systems with complete translational invariance relate the dielectric function to the scattering probability in characteristic-energy-loss experiments. We have extended this relationship to the case of periodic systems. Energy-loss vs momentum-transfer measurements are of value because they pr…
We describe a method of accurately measuring the secondary electron yield of solids over the entire incident energy range of 0–1000 eV in less than 30 msec using a commercial LEED/Auger system. Particular attention is paid to the region of low-energy incident electrons (Ep=0 to 100 eV), and the spatial and energy reso…
Abstract Silicones (polydimethyl siloxanes) greatly increase the oxidative stability of an edible oil at high temperature. The effect is demonstrated here, using a thin layer chromatography technique to follow the oxidation of the oil. The minimum fully effective concentration corresponds to a monolayer of silicone on…
Abstract The effect of previously proposed distributions of particle size and interparticle “gap” lengths on the small‐angle x‐ray scattering of a paracrystalline one‐dimensional macrolattice has been examined. It was concluded that the general paracrystalline model, in which the fluctuations of crystalline and amorph…
The optical properties and practical realization of ion and electron lenses are reviewed. Attention has chiefly been directed to electrostatic and magnetic electron lenses of rotational or planar symmetry, especially to those which seem to offer advantages in scientific instruments. Various competing methods of calcul…
A model of the β to ω phase transformation in Ti, Zr and Hf alloys is proposed whereby the three-dimensional displacive transition is decomposed into one-dimensional and two-dimensional components. The one-dimensional component is postulated to be a linear displacive defect along 〈111〉 closepacked rows of the b.c.c. s…
It is obvious that the title of this article encompasses an area too vast to be adequately covered in a single review paper. Thus, we hasten to remark at the outset that the primary topic to be dealt with here is the relation between the crystal dynamics, on the one hand, and the basic interactions between the valence…
The stress-strain behavior of glass bead-filled polystyrene, styrene–acrylonitrile, styrene–acrylonitrile–butadiene, and polyphenylene oxide composites is studied at various temperatures below their glass transition temperature. Earlier studies of bead-filled composites indicated that the addition of filler decreases…
The anisotropic liquid-structure factor of $p$ -cyanobenzylidene-amino-$p$-$n$-octyloxybenzene has been measured in the nematic phase using $\mathrm{Cu} K\ensuremath{\alpha}$ x rays. This material exhibits a second-order phase transition to the smectic $A$ phase at ${T}_{c}=82.8$ \ifmmode^\circ\else\textdegree\fi{}C.…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure of stannic phthalocyanine, an eight-coordinated tin complexW. E. Bennett, D. E. Broberg, and N. C. BaenzigerCite this: Inorg. Chem. 1973, 12, 4, 930–936Publication Date (Print):April 1, 1973Publication History Published online1 May 2002Published inissue 1 A…
A new concept of the nature of the α1-relaxation mechanism of high-density polyethylene is proposed. This concept is based on the mechanical properties observed in the α-temperature range for as-grown single crystal mats and for samples of bulk crystallized material. The decomposition of the α-multiple-relaxation proc…
Abstract Pulse pile‐up, dead time, escape peaks, background, and peak overlap in Si(Li) spectra are discussed in relation to microprobe analysis, and procedures for carrying out the necessary corrections for quantitative analysis of elements of atomic number 11 to 30 are described. The accuracy is generally comparable…
Sputter deposition of Mo atoms on W substrates (and vice versa) was shown to form uniform overlayers. Such overlayers are ideally suited for studies of the escape length of Auger electrons. The results show that the escape length increases with Auger electron energy as expected. In both Mo and W the escape length of 4…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTActivation of homogeneous catalysts by polymer attachmentRobert H. Grubbs, Carl. Gibbons, LeRoy C. Kroll, Wesley D. Bonds, and C. H. BrubakerCite this: J. Am. Chem. Soc. 1973, 95, 7, 2373–2375Publication Date (Print):April 1, 1973Publication History Published online1 May 200…
Abstract Systematic discrepancies between the experimentally observed phonon dispersion law and that predicted by the theory of the lattice with polarizable ions in the short wavelength region are discussed. The discrepancies appear to be due to the quadrupole deformation of ions, primarily of anions. The adiabatic la…