Materials Literature
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The powder data for anhydrous theophylline (1,3-dimethylxanthine), C 7 H 8 N 4 O 2 , are reported. It is orthorhombic, Pna 2 1 , with a = 24.628 (4), b = 3.833 (2), c = 8.501 (5) Å; U = 802.49 Å 3 ; Z = 4; D m = 1.478, D c = 1.489 Mg m −3 .
New Monte Carlo simulations of electron scattering based on the single scattering model have been performed in the low-energy region for an aluminum target, where two basic equations are required, namely the elastic scattering cross section and the energy-loss rate. We investigated the screened Rutherford equation and…
The behavior of molybdenite in the system Na 2 Si 2 O 5 -K 2 Si 2 O 5 -MoS 2 -H 2 O has been investigated from 340 bars to 1.36 kb in the temperature range 450 degrees to 850 degrees C. Phase relations in the system show enhanced molybdenite solubility in the alkali silicate liquids and coexisting vapors. MoS 2 solubi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAbsolute rate constants for hydrocarbon autoxidation. 31. Autoxidation of cumene in the presence of tertiary aminesJ. A. Howard and T. YamadaCite this: J. Am. Chem. Soc. 1981, 103, 24, 7102–7106Publication Date (Print):December 1, 1981Publication History Published online1 Ma…
By means of crystal etching and scanning electron microscopy the c- and a- axes of skeletal units of Strongylocentrotus purpuratus have been determined. Crystal etching and crystal decoration were found to be equally useful in demonstrating that the spines are single crystals of magnesian calcite. All regions of spine…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron-transfer chemistry of the luminescent excited state of octachlorodirhenate(III)Daniel G. Nocera and Harry B. GrayCite this: J. Am. Chem. Soc. 1981, 103, 24, 7349–7350Publication Date (Print):December 1, 1981Publication History Published online1 May 2002Published ini…
Factors responsible for the high extent of intracellular posttranslational modifications in type IV collagens were studied in a cultured human tumor cell line, HT-1080. These cells do not synthesize any detectable amounts of interstitial collagens but produce type IV collagen at a high rate, corresponding to about one…
Abstract The kinetics and equilibria of SO 2 sorption in Kapton polyimide film have been studied at temperatures from 25 to 55°C and equilibrium sorption pressures up to 0.76 atm. The data are described well by the dual‐mode model of sorption and transport in glassy polymers. The assumption of “partial immobilization”…
Analysis of a model free energy shows that three distinct commensurate phases can exist in a layer of a material having the $2H$-Ta${\mathrm{Se}}_{2}$ structure. Recent experimental results show that two of these phases occur in $2H$-Ta${\mathrm{Se}}_{2}$, with a transition between them at a temperature between 30 and…
The microstructure observed in a Cu-Ni alloy fatigued in multiple glide consists of two sets of similar dipolar walls parallel to two different {100} planes. These are spaced approximately 0.5 μm apart within each set but are arranged in a non-random manner in that L-joints and T-joints among the walls are much more f…
The diagrams of state of 11 binary systems are presented which form EDA Complexes in the liquid dcrystalline state. The influence of the molecular length and the complex stability on the formation of enhanced smectic A phases have been studied.
A variety of homologs of 4-alkylbenzenethio-4′-alkyl or alkoxybenzoates in which the 4′-alkoxy group is C7-C14, the 4′-alkyl group is C7-C12 and the 4-alkyl group is C5-C8 or C10 were prepared and their mesomorphic properties studied by microscopy, DSC and X-ray diffraction. A comparison is made of the mesomorphic pro…
SiTiO 3 capacitor material with indiffused Bi 2 O 3 was studied using SEM, ESCA combined with Ar + ion‐etching, and TEM equipped with EDX. The apparent thickness of a second‐phase layer observed with SEM was found to be influenced by in‐depth effects. ESCA and TEM results show that only a 10‐ to 100‐nm thick layer of…
A major collagenous component of octopus skin was isolated from limited pepsin digests by selective salt precipitation in acidic and neutral solvents. Chromatography on Cm-cellulose of the denatured collagen and sodium dodecyl sulfate-gel electrophoresis, agarose gel filtration, and chemical analysis of the chromatogr…
We report on an extensive study of the frequency and temperature dependent conductivity of largely cis- (CH)x trans- (CH)x, and NH3 compensated and iodine doped materials. The results reveal a strongly temperature (T) dependent dc conductivity and weakly T-dependent ac conductivity for largely cis- (CH)x and for NH3 c…
Na 2 O–3SiO 2 glasses with up to ≅12 wt% water were prepared under high‐pressure, hydrothermal conditions and their electrical conductivities were measured. The conductivity (σ) was found to depend on H 2 O content in a manner similar to the “mixed‐alkali” effect. At constant temperature, σ decreased initially with in…
This part of the paper focuses on the application of the analytical model developed in Part 1 on the uniaxial tension, uniaxial compression, and plane problems (including rotating strain fields and unproportional loading). Identification of the material parameters is discussed in view of the derived results.
The circumstances under which EDX microanalysis can yield serious errors as a function of the crystallographic orientation are discussed. It is shown that such errors can be as high as 50° when examining a fully ordered alloy or compound. Experimental results obtained on CuPt are correlated with a theoretical treatmen…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExperimental evidence for the absence of bonding electron density between inverted carbon atomsPinakpani Chakrabarti, Paul Seiler, Jack D. Dunitz, Arnulf Dieter Schluter, and Guenter SzeimiesCite this: J. Am. Chem. Soc. 1981, 103, 24, 7378–7380Publication Date (Print):Decemb…
Abstract An improved method for the determination of pyridoxal‐5‐phosphate using tyrosine decarboxylase is described.