Materials Literature
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It is well-known that no permanent distribution of free charge can exist in a conductor. A common development of a "relaxation time" concludes that a charge distribution imposed in a conductor will decay exponentially with a time constant ε/σ. This development utilizes Ohm's law, J = σE, with σ constant, which is inap…
Factors which affect the texture and microstructure of Zr-2.5 wt % Nb extruded tubes have been investigated. The major factor that determines th~ texture is the way the metal flows, which is controlled by the die shape, the extrusion ratio and the lubricant. The microstructure is controlled by the temperature during e…
THERE HAS BEEN A NEED FOR A NONDESTRUCTIVE, DYNAMIC TECHNIQUE FOR EVALUATING CERTAIN ELASTIC CONSTANTS OF ASPHALT PAVING MATERIALS. IN THIS STUDY, A METHOD IS DEVELOPED BY WHICH THE DYNAMIC E-MODULUS, G-MODULUS, AND POISSON'S RATIO OF COMPACTED ASPHALT- AGGREGATE SPECIMENS ARE DETERMINED FROM MEASUREMENT OF THE PROPAG…
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation A. Tauber, R. O. Savage, M. D. Grebenau; Magnetic Properties of Single Crystal Ba5Me2Ti3Fe12O31,…
Sodium metaphosphate glasses containing chromium, manganese, cerium, copper, uranium, molybdenum, vanadium and titanium were equilibrated with air at different temperatures. The relative proportions of the oxidised and reduced forms were determined. Spectral absorption of glasses containing each of the above colouring…
Oxidation, cooling, dissolution, and annealing flexure measurements were performed on thin coupons of niobium presaturated with oxygen. Oxidation was done near 425°C in dry oxygen, dissolution in hydrofluoric acid, cooling and annealing in vacuum. From curvature measurements during each process, bending stresses were…
Recent research on solid lubricants for use at high temperatures in air and other gaseous environments is presented. The characteristics of oxide and fluoride lubricants at temperatures to 1,700 F are described. Data is presented for fluoride coatings with silicate and other additives incorporated to give improved wea…
On étudie dans ce mémoire l'énergie de liaison du complexe exciton-donneur-neutre, ainsi que l'influence des effets de polarisation sur cette dernière, en utilisant un potentiel d'interaction déduit des théories du N-corps et du polaron. On s'est de plus placé dans le cadre de l'approximation de Born Oppenheimer, la r…
Abstract Aus lichtoptischen Messungen der Gleitbanddichten, ‐längen, ‐stufenhöhen und ‐ausbreitungsgeschwindigkeit im Temperaturbereich von 245 bis 427 °C an Oberflächen von plastisch verformten Einkristallen der intermetallischen Verbindung MgZn 2 in Abhängigkeit von der Abgleitung werden Schlußfolgerungen für das Ve…
The mass spectra of hexamethylcyclotrisiloxane, octamethylcylo-tetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane vary with ring size. These compounds are occasionally seen to elute unexpectedly from GLC columns under temperature programmed conditions. The two larger ring compounds exhibit i…
The strain-rate dependent hardening behaviour of commercial- grade purity zirconium and its alloy containing 2.5 wt % niobium was investigated by employing a stress relaxation testing method at temperatures from room temperature to 400 C. It was demonstrated that a complete phenomenological description of the mechanic…
Mössbauer spectra of Fe2+ confirm the local trigonal symmetry of tetrahedral and octahedral sites and show that the octahedral ferrous ions have a strong axial magnetic anisotropy, FeZnMo3O8 exhibits ferromagnetic ordering below 20°K; Fe2Mo3O8 is antiferromagnetic below 60°K, In both cases the magnetic moments lie alo…
Condensation of dipyrromethane with 2-formyl-5-methylpyrrole yields, 1,19-dimethyl-1,19-dideoxybiladiene-ac dihydrobromide, which can be cyclised in the presence of nickel or cobalt ions to give the corresponding metal 1,19-dimethyltetradehydrocorrin salts. Hydrogenation of these salts under a wide variety of experime…
The diamagnetic, nonelectrolytic complexes M(CN)4(CNR)4(M = Mo or W; R = Me, Et, Prn, Pri, But, or CPh3) give unexpectedly simple i.r. and Raman spectra in the C–N stretching region. On the basis of X-ray data for Mo(CN)4(CNMe)4, all the complexes are presumed to have dodecahedral configurations.
In the previous paper,1 we have reported that 8-oxoheptafulvene (1) reacts with monocyclic tropones to from adducts (2) containing a novel norcaradiene and cycloheptatriene moieties according to apparent 8 + 2 cycloaddition process.
The quenching stress, which is due to thermal and transformation strains, was presented as afunction of change in lemjlerature distribution which was ilifluenced by quenching melhods and sizes of steels. i n Ihe slale rif sleels during quenching elastic fl arls were discriminated from plastic p aris on Ihe basis of th…
Abstract not Available.
The X-ray structure determination of 5-benzoyloxyoctaethylporphyrin is reported; the porphyrin skeleton is significantly ruffled, with an alteration in geometry of the central ‘hole’, compared to that in porphyrin itself.
The electronic absorption spectra of tetrahalide complexes of ZnII, CdII, HgII, and TlIII have been measured either in solution or as thin films. The effects of second-order spin–orbit coupling account satisfactorily for the observed band intensities and splittings. The one-electron transitions responsible for the low…
The self-association of four simple aliphatic alcohols in ether solution has been investigated. In the concentration range 0·1–1·2 mol dm–3 the principal polymer is in every case the dimer. At 25 °C the dimerisation constants K2(=[dimer]/[monomer]2) have the values 0·49, 0·71, 0·50, and 0·72 for MeOH, EtOH, PriOH, and…