Materials Literature
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Plastic deformation experiments have been performed on Czochralski-grown decagonal Al-Ni-Co single-quasicrystals at temperatures between 780 and 860°C. Compression tests at a strain rate of 10-5s-1 with different orientations of the compression axis relative to the tenfold quasicrystal direction show an anisotropy of…
The adsorption of S 2 on ZnO and Cu/ZnO has been investigated using synchrotron-based high-resolution photoemission spectroscopy. On dosing a clean ZnO surface with S 2 at 300 K, the molecule dissociates. The S is associated first with Zn and at medium coverages with Zn−O sites. When the sulfur coverage is increased t…
Resistance degradation in lead zirconate titanate (Pb(Zr,Ti)O 3 , PZT) thin‐film capacitors has been studied as a function of applied voltage, temperature, and film composition. The mean time‐to‐failure (lifetime, or t f ) of the capacitors shows a power‐law dependence on voltage of the form t f ∝ V −n ( n similar/con…
Two novel bis-terdentate Ir(III)-cyclometalated complexes, [Ir(L1)(L1(-))](2+) (1) and [Ir(L1(-))(2)](+) (2), have been prepared (L1 is 2,6-bis(7'-methyl-4'-phenyl-2'-quinolyl)pyridine; L1(-) is its mono-anion, see Figure 1). To the best of our knowledge, 1 and 2 are the first luminescent and redox-active Ir(III)-cycl…
Monte Carlo simulations, using the cooperative motion algorithm (CMA), have been employed to investigate the statics and dynamics of both symmetric and asymmetric diblock copolymer melts near the order−disorder transition. Investigation of the static properties has revealed the existence of two characteristic temperat…
The morphology of transmission gratings with varying Bragg spacings formed using polymer-dispersed liquid crystals were examined using high-resolution scanning electron microscopy and image analysis techniques. The effect on the morphology of small changes in the overall functionality of the prepolymer syrup was obser…
The structure and mechanism of formation of a novel hexagonal mesostructured vanadium oxide−surfactant composite (HMVO), synthesized by acid-catalyzed hydrolysis of ethanolic cetyltrimethylammonium vanadate (CTAV) solution, has been studied by a variety of spectroscopic techniques. The poorly crystalline CTAV precurso…
The temperature dependence of the NO 2 + NO 3 + (M) ↔ N 2 O 5 + (M) equilibrium has been studied in the temperature range 279.6−294.2 K at a total pressure of 1000 mbar synthetic air in the 200 m 3 EUPHORE simulation chamber facility in Valencia, Spain. Simultaneous determination of the concentration−time behaviors of…
Rapidly solidified magnesium alloys with 8 at%, 15 at%, and 20 at% Al and 1 at% and 3 at% Zn were fabricated by centrifugal atomization followed by hot extrusion. Microstructure of the alloys was composed of a fine-grain magnesium matrix (0.5 μm) with β-Mg17Al12 precipitates. Electrochemical and weight-loss tests were…
The structure stability of perovskite‐type compounds has been quantitatively estimated by applying bond valence calculations to Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) and Pb(Zn 1/3 Nb 2/3 )O 3 (PZN). The bond valence calculations revealed that the bond strength between oxygen and cations in the pyrochlore‐type compounds is great…
Reaction of the first and second generations of monodendrons, bearing peripheral 2,2‘:6‘,2‘‘-terpyridine units (tpy) and focal point benzylic bromine, with phosphine-substituted silsesquioxane Si8O12(CH2CH2PPh2)8 in refluxing THF affords the corresponding dendritic macromolecules with encapsulated polyhedral silsesqui…
Charged organic−aqueous interface electrostatics are assessed in order to clarify potential electrostatic contributions to oriented mineral nucleation at planar organic surfaces. Fatty acid and acidic phospholipid monolayers contacting aqueous solutions of sparingly soluble salts serve as model systems. Monolayer elec…
We have investigated the carbon-13 solution nuclear magnetic resonance (NMR) chemical shifts of C α, C β, and C γ carbons of 19 valine residues in a vertebrate calmodulin, a nuclease from Staphylococcus aureus, and a ubiquitin. Using empirical chemical shift surfaces to predict C α, C β shifts from known, X-ray φ,ψ va…
A polymer blend consisting of polyimide (PI) and polyurethane (PU) was prepared by means of a novel approach. PU prepolymer was prepared by the reaction of polyester polyol and 2,4-tolylenediisocyanate (2,4-TDI) and then end-capped with phenol. Poly(amide acid) was prepared from pyromellitic dianhydride (PMDA) and oxy…
Nanostructured carbon thin films have been produced by deposition of supersonic cluster beams. The clusters are generated by a pulsed arc cluster ion source modified in order to achieve high fluxes and stability. Scanning electron microscopy, Raman, and optical spectroscopy show that the films are a low density networ…
The photoionization of meso -tetraphenylporphyrin (H 2 TPP) within mesoporous MCM-41 silica tube molecular sieves is studied with visible light irradiation at room temperature and 77 K. Porphyrin π-cation radicals (H 2 TPP •+ ) are generated by photoionization within MCM-41 molecular sieves and are characterized by el…
A dramatic variation of the magnetic coupling in large polyiron clusters can be induced by exploiting host−guest interactions. Subtle structural changes and much weaker antiferromagnetic interactions are the result of the substitution of Na+ with Li+ in the hollow core of the cyclic complex [Fe6(OCH3)12(dbm)6] (Hdbm =…
Optically transparent mesoporous silica plates, which are crack-free up to centimeters in size and 0.5 mm in thickness, have been synthesized using a sol−gel process based on the self-organization between surfactant and silicate through the van der Waals-type, weak, multiple, nonbonded interaction in nonaqueous solven…
The results of first principles calculations using AIMPRO (a local-density-functional code) are presented to describe the stability of interstitial Si in diamond. It is found that the 〈100〉 and 〈11 ...
A qualitative explanation is given for the effect wherein red blood cells are oriented in a nonlinear liquid-crystal medium, and it is shown that it is different from the Fröhlich interaction for living biological systems.