Materials Literature
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The relationship between magnetic properties of rare-earth metals and the electron structure of the f shell is considered. Simple concepts are used to show how many-electron quantum numbers of the spin, orbital and total angular momenta of the f shell are related to the Curie temperature, magnetic moment, magnetic ani…
Deoxycytidylate (dCMP) hydroxymethylase from Escherichia coli infected with a T-4 bacteriophage amber mutant has been purified to homogeneity. It is a dimer with a subunit molecular weight of 28,000. Chemical modification of the homogeneous enzyme with N-ethylmaleimide (NEM) and 5,5'-dithiobis(2-nitrobenzoic acid) (DT…
While X-ray crystallographic data on cytochrome c show the reduced and oxidized forms to have very similar structures, there is a considerable body of data, mostly from solution studies, that indicates the reduced form is more stable and that the interior of the protein is less accessible to solvent in this state. The…
The thermal expansivity of zircon-type scandium vanadate (ScVO 4 ) was determined by the X-ray powder diffraction method in the temperature range 300-634 K. The thermal expansion is anisotropic at room temperature as it has a larger coefficient of expansion along the a direction than along the perpendicular direction…
Conductivity, thermoelectric power and Hall effect measurements are reported for V 2 O 5 gels with relative concentrations of V 4+ of 0.005 and 0.11. Both the Seebeck and the Hall coefficient are negative. This is an exception to the rule that the sign anomaly effect should be observed for amorphous semiconductors, i.…
Abstract Poly(1,5‐hexadiene) was prepared and its structure characterized by high‐field 13 C nuclear magnetic resonance. The polymer was shown to contain repeating five‐membered rings separated by methylene bridges, with both cis and trans placements present in a 54 : 46 ratio. The result is compatible with the Marvel…
Abstract The packing densities (Van der Waals volume/molar volume) were determined at 293 K for various epoxide–amine stoichiometric networks. They are noticeably higher than those of linear polymers except strongly hydrogen bonded ones [polyamides, poly(vinyl alcohol)]. By extrapolation of the dilatometric data, it w…
The authors report measurements of both the AC and the DC electrical conductivity of polymeric insulator-conductor composites in a broad range of compositions for frequencies between 1 kHz and 1 MHz. The dependence of the DC conductivity with the additive concentration exhibits a crossover, from a traditional percolat…
The phase transition of an isotropic liquid into an anisotropic phase is described in terms of a bifurcation of the solution of an exact nonlinear integral equation for the pair distribution function. The behaviour of the correlation function of orientational fluctuations for the pair distribution function is analysed.
Abstract A series of four TDI–polypropylene oxide (PO) water‐blown flexible polyurethane foams was produced in which the water content was varied from 2 to 5 pph at a constant isocyanate index of 110. A portion of each foam was thermally compression molded into a plaque. The morphology of both the foams and plaques wa…
Abstract The kinetics of polyesterification of the glycolyzed PET waste with adipic acid is reported. Glycolysis of PET waste was carried out with ethylene glycol at three different ratios of PET waste to glycol. The glycolyzed products could be readily polyesterified by reacting with adipic acid, to give polyester po…
A ferroelectric polarization P (permanent, spontaneous electric dipole moment) is predicted for certain non-racemic liquid crystals based upon simple symmetry arguments. The magnitude of this polarization is a major factor in determining the eletro-optic response times achievable in ferroelectric liquid crystal (FLC)…
Infrared spectra demonstrate that at pressures above 20 gigapascals and room temperature the regular tetrahedral coordination of oxygen around both silicon and aluminum ions is severely disrupted in SiO(2), CaMgSi(2)O(6), and CaAlSi(2)O(8) composition glasses. The spectra are consistent with gradual, pressure-induced…
The specific heats of the β1(DO3) and β′1(18R) phases in a Cu + 16.1 wt% Zn + 8.0 wt% Al alloy are measured at temperatures close to its martensitic transformation temperature by two different calorimetric techniques. In the measured temperature range no appreciable difference in the specific heat values of the phases…
It is shown that a three-mirror device with ideal mirror reflectivities may be used in place of a halfwave plate to rotate the plane of polarization of a plane polarized beam by any angle with no loss of polarization purity. For coated mirrors, with more general reflectivities, specifications are set on the allowed re…
KMO 2 P 3 O 12 cristallise dans le systeme orthorhombique, groupe d'espace Pbnm et sa structure est affinee jusqu'a R=0,028. RbMo 2 P 3 O 12 cristallise dans Pbcm avec R=0,044
A novel technique, which employs \ensuremath{\omega}\ensuremath{\chi}'/\ensuremath{\chi}'' of the longitudinal susceptibility in place of the shape function \ensuremath{\chi}''/\ensuremath{\omega}\ensuremath{\chi}(0), reveals a coupling of the heavily overdamped soft mode to a relaxation mode in the transverse Ising f…
High-resolution Fourier spectroscopy has been used to study bound-to-bound transitions at the deep platinum acceptor in silicon. Phonon replicas have been observed for both the ${P}_{3/2}$ and the ${P}_{1/2}$ Rydberg series; the energy of the pseudolocalized phonon causing the replicas is 7.2 meV. In addition, Fano re…
Scanning-tunneling-microscope images of layer structure dichalcogenides exhibiting charge-density-waves (CDW's) have been studied at 4.2 K. CDW amplitudes in the 2H, 1T, and 4Hb phases of ${\mathrm{TaSe}}_{2}$ have been measured with the strongest CDW phase showing only the superlattice modulation while the weaker CDW…
The photoemission spectra of NiS in both antiferromagnetic and Pauli paramagnetic phases show similar characteristic features of localized d electrons. This finding is in contrast with the results of band-structure calculations which predict drastic spectral changes between the two phases. It is suggested that fluctua…