Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation and Characterization of Four-Branched Star PolystyreneJ. E. L. Roovers and S. BywaterCite this: Macromolecules 1972, 5, 4, 384–388Publication Date (Print):July 1, 1972Publication History Published online1 May 2002Published inissue 1 July 1972https://pubs.acs.org/…
The motion of space charge initially located at the free surface of an insulator is studied as a function of time. Analytic results are given for the following cases: (a) mobility proportional to a power of the field; (b) mobility proportional to a power of the free-carrier concentration; and (c) fast deep trapping wh…
Optical absorption and emission intensities are investigated for trivalent holmium ions in crystals of LaF3 and YAlO3. Oscillator strengths of transitions to all levels up to 40 000 cm−1 were measured from absorption spectra recorded at 300°K. Corresponding oscillator strengths for transitions between J manifolds were…
Magnetism has been a topic of study since the ancient times of science. Judging by the number of papers appearing each year, the group of scientists concerned with the properties of magnetic materials is vastly expanding. The reason for the great interest in this field is not only the wide application which these mate…
The characteristics of glasslike transitions in supercooled liquids and plastic crystals are discussed and a nearest neighbor interaction scheme, termed the ``bond lattice'' model, is proposed to account for the thermodynamic aspects of the phenomenon. Although the excitations of the bond lattice have features in comm…
Abstract The influence of annealing processes on the thermal behavior of organic glasses in the glass‐transition interval has been investigated and analyzed quantitatively. In detailed annealing studies of atactic polystyrene and Aroclor 5460, the absorption of thermal energy superposed on the increase in the specific…
The de Haas-van Alphen frequencies for the symmetry direction orbits and the (110) plane belly turning point have been measured in copper, silver and gold with an absolute precision of better than 2 in 10 5 and a relative precision approaching 1 in 10 6 . The infinite-field phases have been determined by extrapolation…
The reflection, refraction, and associated production of photoelectrons by ultrasoft x rays (10-100 \AA{}) can be important bases for the determination of material constants such as the linear x-ray absorption coefficients and the electron mean free paths. These may then be used to establish directly the photoionizati…
The literature dealing with the high-temperature behavior of inorganic nitrates and nitrites has been critically reviewed. Values of (GTo−H298o)/T of the reactants and products of the decomposition reactions were calculated and have been tabulated from 298 K up to as high a temperature as possible. Equilibrium constan…
The lattice version of the Maier-Saupe model of a nematic liquid crystal, in which all molecules are restricted to be on a simple-cubic lattice with periodic boundary conditions and to interact only with their nearest neighbors through the interaction energy ${E}_{\mathrm{ij}}=\ensuremath{-}\ensuremath{\epsilon}(\frac…
Metallic double-exchange ferromagnets such as doped LaMnO 3 are investigatd on the basis of an efffective Hamiltonian derived from the s - d model Hamiltonian. Resistance at low temperatures is calculated in the spin wave approximation and it is found to be proportional to T 9/2 . Magnetic behaviors of the system at f…
The transient distortions, induced in a nematic film by a stepwise increase (or decrease) of the magnetic field around the threshold value ${H}_{c}$, are accurately measured by conoscopic techniques. The results can be interpreted by the Leslie equations and provide a measurement of a viscosity coefficient.
Abstract On a montré que les fonctions terminales d'un polyoxyéthylèneglycol disodé sont capables d'amorcer la polyaddition de l'ε‐caprolactone. On a préparé de cette manière une série de copolymères triséquencés poly‐ε‐caprolactone/polyoxyéthylène/poly‐ε‐caprolactone, comportant des séquences de longueur variée. Les…
We show that elastic strain energy may account for the tendency of some nematic liquid crystals to lie parallel to the direction of rubbing on a solid surface that has been slightly deformed by rubbing, or perpendicular to a surface that is slightly rough in two dimensions.
SINCE MEADOWCRAFT REPORTED THAT STRONTIUM-DOPED LACO03 WAS COMPARABLE TO PLATINUM AS AN OXYGEN ELECTRODE, THE TESTING OF THE CATALYTIC ACTIVITY OF LACO03 ON CERTAIN GAS SYSTEMS HAS BEEN PURSUED. THIS PARTICULAR RARE EARTH COBALT OXIDE AGAIN HAD ACTIVITY WHICH RIVALED PLATINUM. THE COMPOUND WAS SUGGESTED AS A CANDIDATE…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHemin monomers in micellar sodium lauryl sulfate. Spectral and equilibrium study with cyanideJon SimplicioCite this: Biochemistry 1972, 11, 13, 2525–2528Publication Date (Print):June 20, 1972Publication History Published online1 May 2002Published inissue 20 June 1972https://…
Experimental results given in Part I and II are interpreted with the help of a band scheme including five energy levels: β (1.91 eV above the VB, due to exciton—neutral acceptor complexes creation with 0.1 eV binding energy), A (0.55 eV above the VB, copper vacancies V), B (0.76 eV above A, [V—V] vacancy associations)…
The EPR spectrum of ${\mathrm{Mo}}^{5+}$ in SrTi${\mathrm{O}}_{3}$ at $T=1$. 65 \ifmmode^\circ\else\textdegree\fi{}K is reported. The spectrum is stable in suitably prepared samples or light-induced (3900-4300-\AA{} light) in photochromic samples, and can only be observed at liquid-helium temperatures. The $g$ tensor…
Some rate data for the transfer of a deuterium atom tracer between hydrogen and water vapor, catalyzed by platinum supported on γ-alumina, are reported. Above 100 °C the transfer rate measured at 1 atm total pressure is shown to be free of mass transfer effects, and obeys an initial first order dependence on water vap…
Reflectivity and wavelength-modulation-derivative-reflectivity spectroscopy have been performed on the alloy series ${\mathrm{Pb}}_{1\ensuremath{-}x}{\mathrm{Sn}}_{x}\mathrm{Te}$ throughout the compositional range $0\ensuremath{\le}x\ensuremath{\le}1$. PbTe and SnTe reflectivities were studied from 0.5 to 21 eV and th…