Materials Literature
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The resting state structure of the metallocene−alkyl cation, the coordination of the olefin to the preferred resting state structure, and the insertion process of the Ti-constrained geometry catalyst (CpSiH 2 NH)TiR + have been studied with density functional theory. A combined static and dynamic approach has been uti…
Here we describe the three-dimensional structure of 4-chlorobenzoyl-CoA dehalogenase from Pseudomonas sp. strain CBS-3. This enzyme catalyzes the hydrolysis of 4-chlorobenzoyl-CoA to 4-hydroxybenzoyl-CoA. The molecular structure of the enzyme/4-hydroxybenzoyl-CoA complex was solved by the techniques of multiple isomor…
The edge plasma, D. Reiter wall effects on particle recycling in tokamaks, J.K. Ehrenberg physical sputtering and radiation-enhanced sublimation, W. Eckstein and V. Philipps chemical erosion, E. Vietzke and A.A. Haasz electron emission from solids, J. Schou control of plasma-surface interactions by thin films, J. Wint…
A vertical gradient freeze apparatus was set up to investigate the crystal growth in high magnetic field. In the presence and absence of a magnetic field, temperature profiles were measured from solid-liquid interface to over Te-doped InSb melt, and InGaSb with low GaSb mole fraction and Te-doped InSb crystals were gr…
The magnetic and mechanical properties of 19%Co-1.9%V-0.3%Nb-Fe high strength (/spl sigma//sub y/=90 ksi) soft magnetic alloy were studied after aging at 450/spl deg/C for up to 800 h. The magnetic induction B (H/sub m/=10 and 25 Oe respectively) decreases rapidly in the first 100 h and approaches a lower limit at abo…
We examine the influence of the diverging concentration fluctuations near a spinodal on the dynamics of branched polymer solutions in the vicinity of a sol−gel transition. Dynamic light scattering (DLS) measurements on pregel solutions and gels of methyl methacrylate (MMA) cross-linked with varying amounts of ethylene…
Abstract The absence of a predetermined helical sense in the polyisocyanates causes the formation of helix reversals which enforce a strong cooperativity for the amplification of chiral effects. The helix reversals though also place a limit on this amplification, a limit which would be eliminated by reducing the helix…
Evidence has been found that solid solution of 10 mol% lead titanate in lead magnesium niobate bears strong resemblance to spin and dipolar glasses. The frequency dispersion of the temperature of the permittivity maximum, Tm, has been analyzed using the Vogel-Fulcher relationship. The difference between the solid solu…
The thermal shock fracture mechanism of metal/ceramic functionally graded materials was studied by burner heating test. Dependence of thermal shock crack initiation and propagation on controlled compositional gradients was virtually shown and discussions were made on the basis of fracture mechanics with special refere…
Three homoleptic copper(II) complexes have been prepared which feature 6-halogen-substituted 2-pyridonate ligands [{Cu2(xhp)4}n](n= 1, xhp = 6-chloro- or 6-bromo-2-pyridonate; n= 2, xhp = 6-fluoro-2-pyridonate). X-ray structural analysis of the complexes showed that for the chlorine- and bromine-substituted derivative…
Polymerization of racemic α-methyl-β-propiolactone (MPL) was carried out using Zn-, Sn-, La-, Y-. and Al-based organometallic catalysts. It was found that Zn(C 2 H 5 ) 2 /H 2 O (1/0.6), ( n C 4 H 9 ) 2 Sn(OCH 3 ) 2, Al(O i C 3 H 7 ) 3, and (C 2 H 5 ) 2 AlOC 2 H 5 produced atactic poly(α-methyl-β-propiolactone) (PMPL),…
Abstract The phase separation states of hemicellulose and lignin in their blends were investigated by means of contact angle measurements. The hysteresis behavior in dynamic contact angles suggested that a phase separation of cluster‐state type (not of random dispersion type) took place at hemicellulose‐rich and ligni…
The miscibility of the carbosilane analogue of poly(α-methylstyrene), poly(methylphenylsilylenemethylene), named poly(sila-α-methylstyrene) (PSiαMS) with an M w value of 188 000 and polystyrene (PS) having different molecular weights is investigated using DSC and cloud point measurements. The observed miscibility beha…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Flash Point Value for n-Dodecane Based on the Manual Pensky−Martens Closed Cup Method (ASTM D-93)Janet M. Hughes, Dennis R. Hardy, and Erna J. BealView Author Information Geo-Centers, Inc., Indian Head Highway, Ft. Washington, Maryland 20744 Naval Research Laboratory…
The study of the photooxidation mechanism of crosslinked polyesters used for flat steel coating can be based on the analysis of photoproducts at the molecular scale: these photoproducts are formed in the matrix under exposure in an accelerated photoageing chamber SEPAP 12–24. Hydroxy functionalized aliphatic polyester…
Several thermoplastics and an epoxy were exposed to a variety of conditions to determine the effect of chemical environment on the materials. Weight gain measurements of the samples were made after exposure to low humidity, ambient air, 90/spl deg/C air, ambient transformer oil, and 90/spl deg/C transformer oil. Two m…
Summary The purpose of this study was to investigate effects of aluminium in the Zn coating on electrode life in welding galvanized steel sheet. Three hot‐dip galvanized and one electro‐galvanized steel sheet types were prepared for this study. Aluminium content in the coatings varied within the range 0.26–0.87 mass%…
A series of unsupported nickel–copper catalysts with various Ni/Cu ratios has been prepared by coprecipitation and characterized by thermomagnetometry, (TM), temperature programmed reduction (TPR) and oxidation (TPO) and scanning electron microscopy (SEM). It was found that the magnetization of the nickel–copper catal…
Structure and mechanical properties of the intermetallic compound NiMn alloyed by Ti and Al have been studied using optical and transmission electron microscopy, X-ray diffraction and dilatometry. Alloying has been found to reduce the temperature of β ↔ θ martensitic transformation, the martensite tetragonality and th…
The protonation of 2,3-dimethoxy-5-methyl-1,4-benzoquinone (UQ 0 ) has been determined to improve the quantum efficiency of charge separation between a zinc meso-tetra(4-sulfonatophenyl)porphine (MP) donor and UQ 0 (UQ 0 H + upon protonation) acceptor system. The primary effect of protonation is to increase the drivin…