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The polarized ultraviolet absorption spectra of the tetrahedral CuCl4= ion oriented in single crystals of Cs2CuCl4 and Cs2ZnCl4 have been observed. The spectral bands are identified by means of an analysis which takes into account the observed variations with lattice of the band intensities and positions and which all…
Vapor-pressure and mass-spectrometric measurements on Ti3O5(s) contained in tungsten crucibles show that for the congruent vaporization, Ti3O5(s)=3 TiO(g)+2 O(g),logK=−(1.504±0.011)×(105/T)+39.99±0.59.The vapor-pressure measurements were obtained in the temperature range 1837°—2040°K and are used with auxiliary values…
It is well known that the addition of about 0.2 per cent palladium to titanium significantly increases its resistance to corrosion in non-oxidising acids. It has usually been assumed that the palladium is present as elemental particles at the metal surface and that these function electrochemically to provide anodic pa…
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation R. F. Schaufele, M. J. Weber; First‐ and Second‐Order Raman Scattering of SrTiO3. J. Chem. Phys.…
The symbols as used in the text are defined as follows: p — uniform stress on cross sec-tion due to prestress c — distance to the longitudinal crack from the bottom of beam e — distance to the applied force from the bottom of beam P — applied force L — distance from the end of the beam to a cross section where the str…
The dielectric properties of solid solutions in the system SrTiO 3 -La 2/3 TiO 3 were measured in a frequency range from 200 to 10 5 Hz and at temperatures from -190 to 400°C. The relative permittivity of the solid solutions is lower that of pure SrTiO 3 and pronounced dielectric nonlinearity was not observed. Two sep…
Abstract Some features of the linear theory of an elastic Cosserat plate are discussed and special attention is given to a bending theory which corresponds to the bending of a transversely isotropic three-dimensional plate. A useful representation for the solution of the system of differential equations characterizing…
Thin films of vanadium dioxide have been formed by reactive sputtering of vanadium in an argon atmosphere doped with a partial pressure of oxygen. The films were deposited on sapphire substrates held at 400°C and exhibit a highly oriented polycrystalline monoclinic structure at room temperature. The semiconductor to m…
Thermoluminescence emission above room temperature and optical absorption have been studied in LiF crystals irradiated by gamma rays, with emphasis on conditions which are of greatest interest for applications to radiation dosimetry. The specimens were Harshaw crystals of differing purity, and the purpose was to corre…
The role of pH, temperature, salt type, and salt concentration on the three possible transformations involving the crystalline, dispersed helical, and randomly coiled forms of collagen has been investigated. The results are given in terms of pseudo phase diagrams where the field of stability of each form is delimited…
Abstract The kinetics of alkaline degradation of cotton hydrocellulose were determined in 5% NaOH at various temperatures. An activation energy of 24 kcal./mole was found for the endwise degradation reaction, while that of termination to a stable m ‐saccharinic acid endunit is 32 kcal./mole. Consequently, the DP n of…
The fluorescence of Eu3+-activated lanthanide oxyhalides LnOX (Ln=Y, La, Gd, and X=Cl, Br) is reported. Although all host lattices under consideration are isomorphous, the spectral energy distribution of the Eu3+ emission depends strongly on the choice of X and to a lesser extent on that of Ln. This variation is accou…
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Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.
The glass-transition temperatures of 34 liquids have been measured by differential thermal analysis, and the results compared with the values predicted from viscosity measurements by the equation lnη = A″+B″/(T—T0). In those liquids which have two non-Arrhenius viscosity regions, there is good agreement between observ…
A survey is made of all published data on self-diffusion in liquid metals and an examination is carried out on the temperature-dependence of D for studies covering a wide range of temperatures. Log D versus 1/T and D versus T represent the best data equally well, while D versus T 1/2 and D versus T 2 do not. The prope…
Experiments on the vacuum flashover of dielectric frusta subjected to 35 and 75 nsec pulses show the strong influence of cone angle on insulation strength. A theory is presented to explain the formative process leading to flashover for one polarity. It is proposed that positive surface charge grows by emission of hot…
The molybdates of Sm, Eu, Tb, and Dy are isotypic with ferroelectric Gd2(MoO4)3. Other compositions of this structure occur in the pseudoternary system Gd–La–Y-molybdate and in the pseudobinary system Gd2(MoO4)3–Gd2(WO4)3. A representative number of these compositions were grown as single crystals and tested for ferro…
Abstract Calcium carbonate samples containing known amounts of additives and impurities have been calcined in air at a series of temperatures for different lengths of time. Changes in specific surface and average crystallite size show the effect of the additives and impurities (accessory minerals in limestones and cha…
Rates of tail regeneration in the Madeira wall lizard (Lacerta dugesii) and the slow-worm (Anguis fragilis) were studied. L. dugesii regenerates very rapidly, the new tail sometimes attaining a maximum rate of growth of 2'6 mm a day during the fifth week after autotomy. By the twelfth week 90% of the original tail len…