Materials Literature
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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…
Essentials of Coordination Chemistry. Sigma Pyridine Coordination Compounds with Nontransition Metals. Sigma Pyridine Coordination Compounds with Transition Metals. Coordination Compounds of Metals with Pyridine--l----Oxides. Pi--Coordination Compounds of Pyridine with Metals. Pyridine Intercalation Compounds. Clathra…
The local configuration of polymers results from a competition between entropy effects and attractive forces which provide a high density. The resulting frustration is studied geometrically in a curved space representation reminiscent of the curved space representation for blue phases. Within this frame work, we study…
Abstract
The fatigue properties of the soluted and the sensitized type 304 stainless steel were investigated in high pressure hydrogen up to 4.0 MPa at room temperature. It is found that both the number of cycles to failure and the fatigue limits of the soluted and the sensitized steel decreased with increasing hydrogen pressu…
A novel approach to electron/ion optical synthesis and optimization is presented. Low-aberration field distributions are sought by dynamic programming or optimal control procedures in the form of continuous curves constructed of cubic splines. A very simple algorithm is proposed for the reconstruction of the electrode…
RuCl3·n(H2O) or FeSO4 associated with bipyridyl or substituted phenanthrolines, catalyse the expoxidation of stilbenes by IO4– or ClO–; using phenanthrolines bearing electron donating or withdrawing groups, it is possible to modulate the reactivity of these systems.
The surface of gas atomized ferritic powder, Fe–25Cr, was studied by ESCA and Auger spectro- scopy. During atomization reaction products are formed on the surface of the powder. Due to the very low oxygen potential in the atomizer only oxides of the strong oxide forming elements Cr, Mn, and Si are formed during coolin…