Materials Literature
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Abstract A series of metal and acid salts having poly(alkylbenzimidazoles) as the parent ligand were synthesized. The room‐temperature electrical resistivity of the parent and the salts was measured. Values for the dc electrical resistivity varied from ∼1 × 10 13 ohm.cm for the neutral polymers to ∼1 × 10 6 ohm·cm for…
ADVERTISEMENT RETURN TO ISSUEPREVArticleHysteresis Behavior in Polyether Poly(urethaneureas) Based on 2,4-Toluene Diisocyanate, Ethylenediamine, and Poly(tetramethylene oxide)C. S. Paik Sung, T. W. Smith, C. B. Hu, and Nak-Ho SungCite this: Macromolecules 1979, 12, 3, 538–540Publication Date (Print):May 1, 1979Publica…
Short‐lived radicals such as (1) can be compelled to undergo unusual reactions if they are generated in the presence of a metal colloid catalyst in aqueous solution. Instead of combining, disprotionating, or dismuting, the radicals (1) participate in a redox process leading to evolution of H 2 , according to the overa…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFluxional behavior in octahydrooctaborate(2-). A theoretical studyDaniel A. Kleier and William N. LipscombCite this: Inorg. Chem. 1979, 18, 5, 1312–1318Publication Date (Print):May 1, 1979Publication History Published online1 May 2002Published inissue 1 May 1979https://pubs.…
Starting at room temperature the Hall constant of In-doped lead tin telluride increases exponentially with inverse temperature, then decreases, and finally flattens out. This behavior is explained on the basis of autocompensation and the positive temperature dependence of the band gap.
Abstract The vacuum ultraviolet luminescence of pure and doped MgO crystals excited by 10 keV electrons is studied in the temperature region 80 to 450 K. At 80 K the narrow edge luminescence band at 7.65 eV due to radiative decay of free excitons dominates in the emission spectrum of undoped crystals. At thermal quenc…
The pedological development of a chronosequence of four soils ranging in age from 8000 to 115 000 yr was investigated on Baffin Island, N.W.T. All the soils were developed on granitic morainal material in an Arctic environment. The soils were acid and very gravelly with low clay contents. The major clay minerals in al…
Abstract The radioactivity of Greek lignites and their ashes was studied. It was found that the radionuclides in them belong to the uranium series. Fly ashes are relatively rich in radioactivity. Concentrations up to 7 · 10 -5 g/g and 12 pCi/g were measured for 238 U and 226 Ra, respectively. The associated hazards fr…
Thermal degradation of aromatic polyesters (see text for formula) (m = 2, 3, 4, 5, and 6) was studied by pyrolysis/gas chromatography using a Curie-point pyrolyzer directly attached to a gas chromatograph with a thermally stable polar separation column (Thermon-1000) to cover a wide range of the degradation products.…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolybdenum(IV)-porphyrin derivatives: the oxo(5,10,15,20-tetra-p-tolylporphyrinato)molybdenum(IV), MoO(TTP), and the dichloro(5,10,15,20-tetra-p-tolylporphyrinato)molybdenum(IV), Mo(Cl)21(TTP). Syntheses and structuresTharcis Diebold, Bernard Chevrier, and Raymond WeissCite…
Abstract The tensile mechanical properties of diethylenetriamine (DETA)‐cured bisphenol‐A‐diglycidyl ether (DGEBA) epoxies prepared from 9, 11 and 13 phr DETA are reported as a function of thermal history, strain‐rate and test temperature. These epoxies exhibit macroscopic yield stresses and >10% ultimate elongatio…
Abstract The title compounds can be synthesized by fusion reaction of the alkali carbonates with copper and sulfur at 790 °C. The structure was solved from X-ray diffractometer data of single crystals and refined to an R-value of 0.06. The compounds crystallize with the same layer-type structure which is closely relat…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT3a-Hydroperoxypyrroloindole from tryptophan. Isolation and transformation to formylkynurenineMasako Nakagawa, Shiro Kato, Shigehiro Kataoka, and Tohru HinoCite this: J. Am. Chem. Soc. 1979, 101, 11, 3136–3137Publication Date (Print):May 1, 1979Publication History Published o…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolid Solution Formation and Fractionation in Quasi-Binary Systems of Polyethylene FractionsPaul Smith and R. St. John ManleyCite this: Macromolecules 1979, 12, 3, 483–491Publication Date (Print):May 1, 1979Publication History Published online1 May 2002Published inissue 1 Ma…
Sternheimer shielding functions $\ensuremath{\gamma}(r)$ are derived by means of Sternheimer's procedure for a series of elements (Li, Na, K, Rb, F, Cl, Br, I, Cu, Fe, Ag, and Pr) with varying electronic configurations, with and without valence electrons, which are generally included in molecular-orbital calculations…
A computer simulation is described which allows the study of charge motion in thin polymer films of the type used for electret transducers. The simulation operates with a variety of possible boundary conditions and can include nonlinear transport terms as well as time-varying radiation-induced conductivity. Electron-i…
A series of technical data for the preparation of ferroelectric thin film PLZT by RF sputtering at substrate temperatures lower than 400°C with subsequent annealing is described. Films with dielectric and optical properties of considerable quality have been obtained under certain conditions. Parametric changes in the…
Abstract The aromatic polysulfone poly(oxy‐1,4‐phenylenesulfonyl‐1,4‐phenyleneoxy‐1,4‐phenyleneiso‐propylidene‐1,4‐phenylene) (I) showed no change in flexural yield strength after doses of γ‐radiation up to 600 Mrad in vacuum at 35,80, and 125°C ( T g = 190°C)). However, the flexural strength decreased markedly with d…
The authors present magnetisation measurements performed on a single crystal of TbCo 2 as well as spontaneous distortion studied by X-ray powder diffraction. At any temperature below T c (240K) the easy magnetisation direction is (111) while the most difficult is (100). A huge rhombohedral distortion appears below T c…
ZnO-Br2-O2, ZnCl2-O2, and ZnO-H2-H2O-O2 chemical-vapor-deposition (CVD) systems are studied to obtain as-grown optical waveguides of single-crystalline ZnO on sapphire. The waveguide is made on a very thin sputter-deposited epitaxial layer of ZnO on sapphire by using the ZnO-H2-H2O-O2 isothermal CVD system. The minimu…