Materials Literature
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Raman spectra for Ln 2 O 2 S: Eu (Ln=Lu, Y, Gd and La) have been measured at room temperature. The observed four Raman lines are divided into low and high-frequency groups, each consisting of A 1g and E g modes in representations of D 3d crystal point group. The high-frequency lines shift toward low frequency with inc…
An experimental investigation on the aqueous polymerization of acrylamide with potassium persulfate initiator is reported. Molecular weight averages were measured by viscometry. Non-Newtonian effects were accounted for by extrapolation to high shear rates where the polymer solutions approximated Newtonian behavior. Va…
Maximum stable lengths of the floating-liquids zone (lmax) were measured in the small-diameter (d=0.25–1.5 mm) float-zone crystal growth of sapphire and silicon. A 100-W cw CO2 laser was used as power source. The measured ratios of lmax/d for sapphire and silicon are in good agreement with the theoretical analyses by…
It has been postulated that corrosion of photoanodes and its suppression are correlated with the presence of sulfate radicals. This idea was investigated by measuring the effects of light intensity, Co 2+ concentration, and concentration on corrosion rate. Results showed that corrosion rate was proportional to , that…
Abstract Thermal transformation of chrysotile from Uruaçu District, state of Goiás, Brazil, heated in dry conditions at temperatures from 600°C to 1300°C was studied by high resolution electron microscopy and selected area electron diffraction (SAD). Up to 600°C, no morphological or SAD pattern changes were observed.…
The problems of scattering of plane compressional and shear waves by a class of infinite circular cylindrical flaws and inclusions embedded in an infinite isotropic homogeneous elastic medium are solved. The objects considered are an elastic cylinder, an inviscid-fluid-filled cavity, an empty cavity, and a rigid cylin…
Formation of membranes from a binary system, poly(vinyl chloride) and dimethylformamide, was studied. Phase separation during membrane formation was caused by absorption of aqueous vapor from the atmosphere. The membrane structure was closely related to the degree of phase separation. The membrane formation process wa…
Two epipelic diatoms with contrasting chloroplast morphology were found, which on the basis of valve morphology and the limited criteria available for specific determinations, could fall into one species, Navicula scopulorum Bréb. Investigation using electron microscopy revealed a number of structural differences on w…
Epoxidation of styrene–butadiene block polymers considerably improves their resistance to hydrocarbon oils. Use of peroxyformic acid generated in situ appears to be simple and practical. Although no problems exist when the reactions are carried out in toluene, polymer molecular weight and reactant stoichiometry are im…
The single-crystal elastic constants of vanadium and of vanadium with 1.07, 1.85, and 3.46 at.% oxygen have been measured ultrasonically over the temperature range 4.2–300 K. These compositions cover virtually the complete composition range of the terminal solubility at the temperatures of the experiments. Monotonic b…
${\mathrm{Na}}_{2}$C${\mathrm{O}}_{3}$ has an incommensurate phase transition at 619.5 K. The temperature dependence of a satellite reflection and of the length of the modulation wave vector ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}}_{0}$ has been investigated below this temperature using neutron diffraction.…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical evolution. 33. Photochemical decarboxylation of orotic acid, orotidine, and orotidine 5'-phosphateJ. P. Ferris and P. C. JoshiCite this: J. Org. Chem. 1979, 44, 13, 2133–2137Publication Date (Print):June 1, 1979Publication History Published online1 May 2002Published…
The acoustic scattering properties of spherical gas bubbles in a liquid differ from those of a pressure-release sphere by the well-known ’’giant’’ monopole resonance at very low frequencies, which is due to the compressibility of the gas contained in the bubble. We show here that, in addition to this monopole resonanc…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure of nitric oxide and nitrogen dioxide sorption complexes of partially cobalt(II)-exchanged zeolite AWyona V. Cruz, Peter C. W. Leung, and Karl SeffCite this: Inorg. Chem. 1979, 18, 6, 1692–1696Publication Date (Print):June 1, 1979Publication History Publishe…
Abstract In order to clarify the crystal structure and intermolecular cohesion forces of ethylene‐vinyl alcohol copolymers (EVA), the elastic modulus ( E t ) of EVA copolymers was measured. We proposed that EVA copolymers are crystallizable over the entire range of copolymer composition and can produce, an isomorphous…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis, structure, and properties of the oxygen-deficient bis(3,5-di-tert-butylcatecholato)oxomolybdenum(VI) dimer, [MoO(O2C6H2(t-Bu)2)2]2Robert M. Buchanan and Cortlandt G. PierpontCite this: Inorg. Chem. 1979, 18, 6, 1616–1620Publication Date (Print):June 1, 1979Publica…
A styrene–butadiene–styrene (20–60–20) linear block polymer was epoxidized in toluene and cyclohexane solutions with peroxyformic acid generated in situ. The epoxidized polymer, containing about 8% oxygen, exhibits greatly improved resistance to ASTM oils. It can be readily compounded with carbon black, and the unvulc…
Two additional carbohydrates are reported whose crystal structures trap electrons intermolecularly in single crystals x irradiated at low temperature, namely sucrose and rhamnose. Five carbohydrate and polyhydroxy compounds are now known which exhibit this phenomenon. The following characteristics of the phenomenon we…
Abstract The reversible stress‐induced crystal‐crystal phase transition of poly(tetramethylene terephthalate) (PTMT) has been studied using infrared spectroscopy. Two spectral regions were used to study this transition: the 900–1000 cm −1 methylene rocking region and the 1300–1550 cm −1 methylene bending region. The b…
Abstract The depolarized forward‐scattered light from solutions of rat tail collagen has been studied by photon correlation spectroscopy. The measured autocorrelation function is seen to decay on two widely different time scales. The decay time for the fast component is consistent with the rotational diffusion of rodl…