Materials Literature
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Abstract K 2 YZr(PO 4 ) 3 and K 2 GdZr(PO 4 ) 3 were found to have the langbeinite-type structure (K 2 Mg 2 (SO 4 ) 3 ). We determined the crystal structure of these compounds from powder diffraction data. They are cubic P2 1 3 (no. 198), with a = 10.3346(1)Å and a = 10.3457(3)Å respectively. The intensity values we o…
We report accurate temperature dependent measurements of optic indices of refraction, the birefringence, and the strain in the ferroelectric tungsten bronze crystals Ba0.25Sr0.75Nb2O6 and two compositions of (Ba2−xSrx)2(K1−yNay)2(NbO3)10. These results are compared to our previous results in Ba0.4Sr0.6Nb2O6. From the…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAlkane reactions with photoactivated decatungstate in neutral and acid solution: molecular orbital theoryS. F. Jen, Alfred B. Anderson, and Craig L. HillCite this: J. Phys. Chem. 1992, 96, 13, 5658–5662Publication Date (Print):June 1, 1992Publication History Published online…
Abstract Iron-rich dioctahedral 2:1 clays were sampled in metalliferous sediments from Atlantis II Deep (Red Sea), and studied by XRD, TEM, FTIR and Mössbauer spectroscopy. One sample with the structural formula (Si 3·94 Fe 3+ 0·06 )(Fe 3+ 1·90 Mg 0·10 )K 0·1 (Mg, Ca) 0·03 is closer to the theoretical end-member ferri…
Abstract The crystal structure of sophiite, Zn 2 (SeO 3 )Cl 2 (a = 10.251(4), b = 15.223(2), c = 7.666(5) Å, Z = 8) was solved in space group Pccn from single crystal X-ray data, and refined to R = 0.053 for 666 F o > 4o F o . The mineral belongs to layer compounds. The threefold coordinated Se atom is at the apex…
The most basic single axial cyclic motion (i.e. fatigue) tests by the alternative heating up and cooling down of shape memory Ti-Ni50.2at%wires were performed. Heating up was done by direct current method or temperature controllable water-bath and the characteristics on the cyclic motion and its degradation in shape m…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEfficient catalysis of a redox reaction by an artificial enzymeHongping Ye, Weida Tong, and Valerian T. D'SouzaCite this: J. Am. Chem. Soc. 1992, 114, 13, 5470–5472Publication Date (Print):June 1, 1992Publication History Published online1 May 2002Published inissue 1 June 199…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSteric effects in photochromic polysiloxanes with spirooxazine side groupsAlexander Zelichenok, Frida Buchholtz, Shlomo Yitzchaik, Judith Ratner, Mark Safro, and Valeri KrongauzCite this: Macromolecules 1992, 25, 12, 3179–3183Publication Date (Print):June 1, 1992Publication…
Abstract XPS was used to study the initial stages of aluminium deposition on polypropylene. Aluminium was ion sputtered in the preparation chamber of the spectrometer with controlled oxygen and H 2 O partial pressures. The surface composition of the polymer before and after metallization was analysed by XPS and the co…
The effect of time-periodic vertical gravity modulation on the onset of thermosolutal convection in an infinite horizontal layer with stress-free boundaries is investigated using Floquet theory for the linear stability analysis. Situations for which the fluid layer is stably stratified in either the fingering or diffu…
TiO 2 above 4 mol% is an effective nucleating agent for CaO–P 2 O 5 glass which also contains substantial SiO 2 and Al 2 O 3 additions. Glass ceramics can be made from this glass using a single slow heating ramp with no need for a nucleating heat treatment step. Powder of this composition crystallizes rapidly to β‐Ca…
Abstract Hydrogen and hydrogen‐containing species (H 2 O, OH etc.) play a dominant role in the various properties of glass surfaces and technical oxidic thin films deposited on glass. The amount of hydrogen and its distribution with depth are influenced by preparation and production processes, film materials, density…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemical deposition of a conducting polymer, poly(thiophene-3-acetic acid): the first observation of individual events of polymer nucleation and two-dimensional layer-by-layer growthFeng Bin Li and W. John AlberyCite this: Langmuir 1992, 8, 6, 1645–1653Publication Dat…
The oxidation reaction equilibrium constant and the holes mobility in p ‐type‐semiconducting SrTiO 3 single crystals were determined directly by simultaneous Hall and conductivity measurements between 500° and 1000°C. This information and the SrTiO 3 defect model were used to interpret the electrical measurements take…
High-speed rotational angioplasty is being evaluated as an alternative interventional device for the endovascular treatment of chronic coronary occlusions. It has been postulated that this type of angioplasty device may produce particulate debris or cavitations that induce myocardial ischemia. To determine the clinica…
Abstract The dynamical behavior of the Bombyx mori silk fibroin chain and of absorbed water in silk fiber, film, and powder has been studied by 1 H pulsed nuclear magnetic resonance (NMR). Segmental motions do not occur and only the rapid rotation of the methyl groups of alanine residues is observed from −120 to 130°C…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPlasticization of bacterial poly(3-hydroxybutyrate)Giuseppina Ceccorulli, Maria Pizzoli, and Mariastella ScandolaCite this: Macromolecules 1992, 25, 12, 3304–3306Publication Date (Print):June 1, 1992Publication History Published online1 May 2002Published inissue 1 June 1992h…
Abstract The surface excesses of Na and Cl on synthetic imogolite and allophanes with varying Al/Si molar ratios in 0.10 M and 0.01 M NaCl solutions were determined using 22 Na and 36 Cl as ion probes. The point of zero net charge (PZNC) values ranged from 4.1 to 8.4, increasing with the Al/Si molar ratio for the allo…
Abstract The expandability of K-depleted biotite and natural vermiculite was studied using transmission electron microscopy (TEM) and X-ray diffraction (XRD). K-depletion in layer-silicates was achieved by treating ultrathin sections with 0·1 m CaCl 2 and BaCl 2 solutions. The natural sample of biotite, which by XRD r…
An unconstrained simulation of the GTP-bound form of the H-ras protein p21 is performed in an aqueous environment with charge-neutralizing counterions. The simulation is compared to the 1.35-A structure of Pai et al. [(1990) EMBO J. 9, 2351] and a proposed alternate structure, in which the loop at residues 60-65 is mo…