Materials Literature
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The intense bright red color of the diprotonated derivatives of rubyrin (1), the largest expanded porphyrin to be characterized so far, is the source of the compound's name. A diprotonated alkyl derivative of 1 was synthesized efficiently. The molecule is nearly planar in the crystal—not unexpected for a large porphyr…
The kinetics of the reversible folding and unfolding of Escherichia coli dihydrofolate reductase have been studied by stopped-flow circular dichroism in the peptide region at pH 7.8 and 15 degrees C. The reactions were induced by concentration jumps of a denaturant, urea. The method can detect various intermediates tr…
Gallium is a metal that literally melts in your hand. It has low toxicity, near-zero vapor pressure, and a viscosity similar to water. Despite possessing a surface tension larger than any other liquid (near room temperature), gallium can form nonspherical ...Read More
Drop tubes and electromagnetic levitation are described as techniques for containerless processing. The constraints of maximum undercoolability of metals are discussed with respect to thermodynamic considerations and the onset of homogeneous nucleation. Dendrite growth occurring in undercooled melts is described on th…
ABSTRACT The nuclear gene encoding the small subunit (16S‐like) ribosomal RNA molecule was sequenced from four isolates of the marine coastal planktonic diatom Skeletonema costatum (Grev.) Cleve. Each isolate originated from a geographically separate water mass. Sufficient morphological and genetic differences were fo…
Part 1 Precipitation and nucleation: studies on the early stages of crystal nucleation, R.Popovitz-Biro et al solute clustering and secondary nucleation, M.A.Larson induction time in seeded and unseeded precipitation, M.S. van der Leeden et al dissolution kinetics of calcium phosphates involved in biomineralization, J…
In its simplest form, the geometric model of crystal growth is a third‐order, nonlinear, ordinary differential equation for θ ( s , ε ): urn:x-wiley:-wiley:00222526:media:sapm1991852129-math-0001 A needle crystal is a solution that satisfies boundary conditions urn:x-wiley:-wiley:00222526:media:sapm1991852129-math-000…
The degradation of the electrochromism of amorphous WO 3 and WO 3 ‐ TiO 2 films prepared by electron‐beam deposition have been studied. The lifetime of the WO 3 ‐ TiO 2 films is five times longer than that of the WO 3 films. SIMS and XPS analyses have revealed that lithium accumulates as OLi in the WO 3 films, but tha…
Grossular garnets from 33 localities were examined for indications of OH- or H_2O in their infrared spectrum. All contained OH-. Classical hydrogrossular with more than 5 \nwt% H_2O displays systematics pectroscopic behavior consistent with the hydrogarnet substitution consisting of two absorption bands at 3598 an…
The macromolecular structure of type X collagen in the matrices of primary cultures of chick hypertrophic chondrocytes was initially investigated using immunoelectron microscopy. Type X collagen was observed to assemble into a matlike structure with-in the matrix elaborated by hypertrophic chondrocytes. The process of…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactions of hydroperoxides with metallotetraphenylporphyrins in aqueous solutionsThomas C. BruiceCite this: Acc. Chem. Res. 1991, 24, 8, 243–249Publication Date (Print):August 1, 1991Publication History Published online1 May 2002Published inissue 1 August 1991https://pubs.a…
We review recent work in the application of Auger and X-ray photoelectron diffraction at high electron kinetic energies to the problem of structure determination in ultrathin epitaxial overlayers. These closely-related techniques are based on the fact that outgoing Auger and photoelectrons from single-crystal specimen…
Phase relations in the BaTiO 3 —TiO 2 system were studied at temperatures above 1300°C in air. Quenching experiments were performed with high‐purity reagents, and a new equilibrium phase diagram was constructed. Results include redetermination of the liquidus boundaries, the eutectic temperature, the melting or decomp…
Trends in recently reported data on high sp3 fraction (up to 85%), nonhydrogenated amorphous diamond-like carbon films deposited by ion beam sputtering and laser vaporization are examined. The degree of diamondlike film character is found to depend upon the deposition technique as well as the substrate temperature and…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNovel template effects of distannoxane catalysts in highly efficient transesterification and esterificationJunzo Otera, Nobuhisa Danoh, and Hitosi NozakiCite this: J. Org. Chem. 1991, 56, 18, 5307–5311Publication Date (Print):August 1, 1991Publication History Published onlin…
Thick (100 μm) chemical vapour deposited (CVD) polycrystalline diamond films have been observed to emit electrons with an intensity sufficient to form an image in the accelerating field of an emission microscope without external excitation (> 3 MV/m). The individual crystallites are of the order of 1–10 μm. The com…
The structural and magnetic properties of BaFe12−2xCoxTixO19 (0≤x≤1.0) M-type barium ferrite have been investigated by means of neutron powder diffraction and high-field magnetization measurements. The cationic distribution and magnetic moments of the five different metallic sublattices are determined and compared to…
In an earlier paper we reported measurements of the activation energy for sintering from constant‐heating‐rate experiments with alumina/5% zirconia. Here, results from a full range of compositions in this two‐phase system are described. They show that the activation energy remains in the range 700 ± 100 kJ/mol when th…
Binding of ethidium to DNA increases the fluorescence efficiency of the molecular ion by about 1 order of magnitude. Quenching of the fluorescence of such an ethidium.DNA complex by tetrakis(4-N-methylpyridyl)porphine (H2T4), and its nickel(II) and zinc(II) derivatives (NiT4 and ZnT4), was investigated in the present…
The mechanism of corrosion inhibition of iron by acetylenic alcohols in acid solutions was established by relating the interfacial structure obtained from spectroscopic measurements with the corrosion reaction kinetics obtained from electrochemical measurements. A modified adsorption interaction model was found to be…