Materials Literature
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F.t.i.r. spectroscopy has been used for the study of dehydration of heteropolyacids (HPA) of the series H3+xPMo12–xVxO40 carried out in vacuo at 298–673 K and also for the study of ammonia sorption on the same samples. Pumping at room temperature results in the departure of water of crystallization; the protons, which…
A sulfide ion at the center of an Ni6 prism capped by two additional Ni atoms, and the presence of nine μ2-StBu bridges are the characteristic features of the structure of 1. The mean oxidation state for nickel in diamagnetic 1 is + 1.25. The anion 1 is the first pure nickel–sulfur complex with nickel in an unusual ox…
Grain‐oriented Bi 4 Ti 3 O 12 ceramics have been prepared by hot‐pressing. Platelike grains align during hot‐pressing; the long‐axis direction perpendicular to the crystal c axis is oriented perpendicular to the pressing direction. The effects of hotpressing conditions such as temperature, pressure, time, and type of…
The heteropolyanions [XW11O39{MnII(OH2)}]n–[X = P(1), Si (2), Ge (3), or B (4)] and α2-[P2W17O61{MnII(OH2)}]8–(5) have been transferred into non-polar solvents (benzene, toluene) with the aid of tetraheptylammonium bromide or other phase-transfer agents. Following dehydration of their non-polar solutions, anions (2) a…
The band gap of the mixed perovskite BaSn1–xSbxO3 has been reported to be 134 kJ mol–1(J-M. Hermann, M. R. Nunes and F. M. A. da Costa, J. Chem. Soc., Faraday Trans. I, 1982, 78, 1983), corresponding to 1.4 eV, which is the optimum value for solar-energy conversion. In order to confirm this value, pressed discs of the…
The increased discharge burnups envisaged today require an optimization of the Zircaloy cladding properties with regard to corrosion with different strategies for optimizing the corrosion for boiling water reactor (BWR) and pressure water reactor (PWR) applications. A broad laboratory study showed that the influence o…
The monthly flux of diatom taxa at four sites in two fjords of British Columbia, Canada, was determined over a 3-year period by particle interceptor traps. Saanich Inlet is a small basin with little horizontal density gradient while Jervis Inlet experiences seasonal runoff and strong vertical stratification. The basic…
The coercivity of Nd-Fe-B sintered magnets has been improved by Al additions. To study the microstructural effect of Al addition, two types of investigation were formed: (1) the change in the wetting behavior of the liquid phase, at the sintering temperature, was studied by measurements of the wetting angle; and (2) t…
The hot working is done at a low strain rate (hot pressing) and a high strain rate (hot rolling). Magnetic alignment induced by the hot working is found to be closely related to the microstructure of the cast ingots and the direction of principal stress. The appropriate structure is a columnar structure. The c-axis of…
Amorphous BN that contains hydrogen could be synthesized by pressure pyrolysis of borazine below 700°C at 100 MPa. The fraction of B and N bonded to H in the pyrolysis product could be controlled by changing the pressure pyrolysis condition. The pyrolysis product at 700°C and 100 MPa showed formation of B‐N‐B bonds of…
From the variation of magnetic properties with temperature trans-bis[1,2-bis(diethylphosphino)ethane]-di-iodochromium(II) undergoes a sharp S= 2 to S= 1 spin-state transition between 165 and 175 K.
The rate of alkene epoxidation promoted by 30% H2O2 and catalysed by MnIII tetra (2,6-dichlorophenyl)porphyrin is strongly enhanced by the addition of lipophilic carboxylic acids and lipophilic imidazole or pyridine axial ligands, in 1–8 : 1 and 1 : 1 molar ratios with respect to the porphyrin.
—The influence of the roughness of solid surfaces on the contact angle hysteresis, Δ, was studied for low-energy solids (paraffin, PTFE, PMMA) using pure liquids. Taking Δ as dependent on the roughness, the contact angle data can be linearly approximated. The value of Δ = 0 is considered as the equilibrium contact ang…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxidative co-oligomerization of guaiacol and 4-chloroanilineKathleen E. Simmons, Robert D. Minard, and Jean Marc BollagCite this: Environ. Sci. Technol. 1989, 23, 1, 115–121Publication Date (Print):January 1, 1989Publication History Published online1 May 2002Published inissu…
Three kinds of corrosion tests, a humidity test (80 degrees C, 90% RH), an autoclave test (120 degrees C, 2 atm saturated with water vapor), and a salt spray test (35 degrees C, 5% NaCl), were performed on a sintered magnet treated with nickel plating. For comparison, samples with epoxy resin coating, Al ion plating,…
Abstract Cationic starches are widely used as wet end additives in paper making. They provide many benefits, classified into 4 categories: improvement of mechanical strength; better retention of fines and fillers; faster drainage; reduction of waste water pollution. According to the accepted theory, a 2‐part electrica…
Polymer films containing droplets of nematic liquid crystal form an important class of new electro-optic light valves and displays. While previous work has shown that the nematic droplet size is an important factor in the electro-optic properties of these films, here we report that the droplet shape is equally importa…
Performed measurements showed that in Na0.5Bi0.5TiO3 single crystals the long-time variation of the electric permittivity is connected with the existence of polar regions. The size and dynamics of the polar regions change with temperature. These regions may be ordered in an external electric field.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 NMR investigation of local dynamics in bulk polymers at temperatures well above the glass-transition temperature. 3. cis-1,4-Polybutadiene and cis-1,4-polyisopreneR. Dejean de la Batie, F. Laupretre, and L. MonnerieCite this: Macromolecules 1989, 22, 1, 122–129Publ…
A supported Mn–porphyrin catalyst was prepared by strong adsorption of the tetracationic Mn[meso-tetra(4-N-methylpyridiniumyl) porphyrin](Cl)4+4Cl– on silica, and was found very efficient for cyclo-octene epoxidation (95% yield, 13 turnovers per min) and for alkane hydroxylation, with alcohol yields and alcohol: keton…