Materials Literature
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Scanning and transmission electron microscopy and the C-Pt replica technique have been used to investigate grain boundary structures in sintered polycrystalline A12O3 with varying concentrations of MgO dopant. A method is proposed for evaluating the fracture toughness, Kβb c, and the strength of grain boundaries from…
A retarding field energy analyser for quantitative voltage measurements which functionally connects a uniform extracting field with a hemispherical analysing field is described. The design principles are : (i) the centres of the hemispherical grids are to be put on the virtual source from which the secondary electron…
Abstract Plasma polymerizations of bis(dimethylamino)methylsilane (BDMAMVS), bis(dimethylamino) methylvinylsilane (BDMAMVS), and trimethylsilyldimethylamine (TMSDMA) were investigated by elemental analysis, IR spectroscopy, and ESCA. Polymer deposition was fairly faster in the BDMAMVS and TMSDMA systems than in the BD…
Abstract The thioarsenate(III) Cs 2 As 8 S 13 has been prepared by the reaction of Cs 2 CO 3 with As 2 S 3 in aqueous solution under pressure at 180 °C. Its structure has been established by X-ray structural analysis. The polymeric anion (As 8 S 13 2- ) n is composed of individual As 4 S 4 -rings, which are each conne…
Abstract Halato telechelic polymers are well-characterized ion-containing polymers the investigation of which gives the scientist a clear insight into the role played by the ions in the modification of the base polymer properties. The end-neutralization of very short length, α,É-dicarboxylic acid polydienes by alkali…
The equilibrium vaporization of UMoO 6 (s) in dry air was studied by the transpiration method in the temperature interval 1110°≤ T (K) ≤ 1250°. Apparent pressure of the trimer measured over the two‐phase mixture UMoO 6 + U 3 O 8 , with dry air as the carrier gas, was used to calculate the partial pressure of the trime…
Standard symbols representing crystal families, two- and three-dimensional Bravais-lattice types and arithmetic classes are recommended for use by the IUCr. The six crystal families are designated by lower-case letters. The family letter in the symbol of each of the 14 lattice types is followed by an upper-case letter…
The density, refractive index and ultrasonic velocity dependence on temperature for N-(p-npentyloxybenzylidene)- p-n-octylaniline, 50.8, is presented. The compound 50.8 exhibits smectic-B, smectic-A and nematic phases between the solid and isotropic liquid phases. The nematic-isotropic and smectic A-smectic B phase tr…
The ceric ion method has been used to graft acrylic acid directly onto cellulose with a minimum amount of homopolymer. The method utilizes the pretreatment of the cellulose with ceric ammonium nitrate followed by washing out any excess of the catalyst. Oxygen can be present with the pretreatment step, but must be excl…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermolysis rates and products of the putative ketochloroallyl groups in poly(vinyl chloride), as inferred from the behavior of analogous model compoundsMary G. Panek, Gilberto M. Villacorta, and William H. Starnes Jr.Cite this: Macromolecules 1985, 18, 5, 1040–1041Publicati…
Abstract A method is proposed for the measurement of cation‐exchange capacity (CEC) of leached soils carrying both variable and constant negative charges at conditions pertinent to the field. The method consists of equilibrating a soil with 0.01 M SrCl 2 (five centrifuge washings), replacing the retained Sr with 0.5 M…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and structure of the first 20-Bi-9 system: a discrete nine-coordinate 20-electron bismuthConstantine A. Stewart, Joseph C. Calabrese, and Anthony J. Arduengo IIICite this: J. Am. Chem. Soc. 1985, 107, 11, 3397–3398Publication Date (Print):May 1, 1985Publication His…
A pulse electr-optical technique is described which allows the molecular tilt angle and optical anisotropy of ferroelectric liquid crystals to be measured. The technique provides high accuracy and reproducibility of the measurement and is insensitive to the non-homogeneity of a liquid crystalline layer. The temperatur…
The probability formulas given in Parts I and II of this series have been improved by incorporating the information contained in Sim's distribution. Possible applications to the discrimination of the phase ambiguities arising from the single isomorphous replacement technique, the one-wavelength anomalous scattering (O…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh-spin .tautm. low-spin transition in solid Co(H2fsa2en)(H2O)2[H4fsa2en = N,N'-ethylenebis(3-carboxysalicylaldimine)]: a magnetic investigationJacqueline Zarembowitch, Renee Claude, and Olivier KahnCite this: Inorg. Chem. 1985, 24, 10, 1576–1580Publication Date (Print):Ma…
A new complete scheme of symmetry analysis for incommensurate modulated structures is applied for the first time to the important ceramic material mullite ${\mathrm{Al}}_{2}$(${\mathrm{Al}}_{2+2\mathrm{x}}$${\mathrm{Si}}_{2\mathrm{\ensuremath{-}}2\mathrm{x}}$)O $_{10\mathrm{\ensuremath{-}}x}\ensuremath{\square}_{x}$.…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTemperature dependence of the voltammetric response of thin electroactive polymer filmsJames Q. Chambers and Gyorgy. InzeltCite this: Anal. Chem. 1985, 57, 6, 1117–1121Publication Date (Print):May 1, 1985Publication History Published online1 May 2002Published inissue 1 May 1…
Abstract The influence of the N ‐alkyl group of tertiary hindered amines on the photostabilization of polymers was studied. The photostabilizing effects of the tertiary amine derivatives of 4‐benzoyloxy‐2,2,6,6‐tetramethylpiperidine ( 1a ) in polypropylene were compared. All tertiary amine derivatives having α‐H to hi…
Abstract The formation of liquid‐crystalline structure in hydroxypropyl cellulose (HPC) in the solvent 2‐hydroxyethyl methacrylate (HEMA) is described. In addition, an attempt is made to preserve the ordered structure of HPC in a composite by polymerizing the solvent. Optical evidence, including refractive index, abso…
Using an adiabatic scanning calorimeter we have studied the thermal behavior of the liquid crystalline material heptyloxybenzylidene-heptylaniline in the temperature range between 52°C and 86°C. In this temperature range a rich variety of liquid crystalline and plastic crystalline phases and phase transitions could be…