Materials Literature
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The structure of W(TPP)(O)(O2)(TPP = tetraphenylporphyrinato) has been shown to have a cis arrangement of oxo and peroxo groups which are eclipsed with respect to the porphyrin nitrogen atoms.
Abstract Accurate estimation of amino acids composition has been carried out for hydrolysates of four varieties of Indian silks, viz., Mulberry, Tasar, Eri, and Muga. These studies have revealed that the hydrolysate (hydrofibroin or crystalline region) in the case of Mulberry consists of glycine, alanine, and serine,…
Novel polycarbonates containing tertiary or secondary benzylic diol structure are prepared via their bis-carbonylimidazolide derivatives under phase transfer conditions; these polycarbonates are designed to undergo a near instantaneous depoluymerization to volatile monomeric species when heated to a critical temperatu…
Description Provides the latest information on the serious corrosion problems that can occur to thermally insulated plant equipment, tankcage and piping components if the insulation becomes wet and reviews the various control and inspection methods being used and under development
The results of sea water corrosion tests on five copper alloy heat exchanger materials are presented. The tests were undertaken to determine whether ammonia, commonly present as a pollutant in sea water, would adversely affect their corrosion behaviour. All five alloys proved more susceptible to crevice attack in the…
High-resolution cross-polarisation magic-angle spinning (CP/MAS)15N n.m.r. spectroscopy of solid [RuCl(NO)2(PPh3)2](BF4) shows a large chemical shift anisotropy for the bent as compared with the linear nitrosyl ligand (in contrast to solution 15N n.m.r. which shows a bent–linear ligand fluxionality): in solid [Ru(NO)2…
Etude experimentale sur un alliage Fe-24,9% at. Pt. Le parametre d'ordre a ete determine par diffraction de rayons X et les temperatures de transformation par mesure de resistance electrique en fonction de la temperature
The lanthanide(III) tris(heptafluorodimethyloctanedionates), [Ln(fod)3], form solid adducts with pyrazine (pyz) resulting in an increase in co-ordination number of the lanthanides from 6 to 7. In these adducts pyrazine co-ordinates through only one of its nitrogen atoms. The praseodymium, europium, and ytterbium adduc…
Single crystals of As 2 Te 3 were prepared hydrothermally by heating and gradually cooling a mixture of stoichiometric quantities of powdered As and Te in a HCl 25% w/w solution in a quartz ampoule. The crystal structure was determined by using the intensities of 600 independent reflections, measured on a computer con…
Abstract
On etudie les facteurs contribuant a l'excellente resistance aux chocs thermiques des refractaires contenant du graphite: dilatation thermique, module d'elasticite, mecanisme de rupture, deformation, conductivite thermique
Manganese sulphide powders, prepared by a sulphur deoxidation of MnSO4, were melted at 1700°C in a graphite crucible, and then solidified into buttons, about 20mm diameter and 15mm long. Several kinds of bulk manganese sulphide with additives were prepared from powder mixtures of MnS and one of Al2O3, SiO2, MnO, CaO,…
A series of shell samples has been studied to determine the magnitude and mechanisms of carbon exchange between shells and their environment. Laboratory contamination experiments included the storing of shell samples in acid and calcareous environments of different 14 C concentrations as well as studies of carbon exch…
Fe-Al alloy films have been obtained by rf sputtering technique and have been investi. gated by means of X-ray diffraction, magnetization and Mössbauer effect measurements A well disordered bcc phase is extended up to about 70at % Al, an amorphous phase between 75 and 85at % Al and an fcc phase from 90 to 100at % Al.…
Abstract
The gas electron diffraction pattern of bis(neopentyl)manganese is consistent with a monomer with ∠CMnC = 180° and Mn–C = 210.4(6) pm.
The principal kinetic product in the Rothemund template synthesis of sterically hindered tetra-arylporphyrins is not the metalloporphyrin complex but the bis(dipyrromethene) complex; the latter has been isolated from a typical porphyrin preparation, that of tetrakis(2,6-dichlorophenyl)porphyrin, and characterized by u…
The homologous series of thermotropic nematic main-chain polyesters [graphic omitted] has been investigated. In the case of even values of n, a smectic phase appears at n= 18. An odd–even oscillation of nematic order parameters associated with the mesogen is observed near the clearing temperature, Tc. At the same time…
The structure of liquid formamide has been examined by X-ray analysis. It is concluded that there are distorted ring dimers which consist of hydrogen-bonded formamide molecules in the liquid state. The most likely model is similar to the crystal structure of formamide.
The reactions of ground-state oxygen and nitrogen atoms with phosphine have been studied using a discharge-flow system with detection of both free-radical and molecular species by molecular-beam sampling mass spectrometry. By observing the decay of PH3 in an excess of O, the rate constant for the reaction O + PH3 [gra…