Materials Literature
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The environmental and metallurgical factors in the intergranular stress corrosion cracking of austenitic stainless steel at temperatures below 100 C has been examined. The behavior of annealed and sensitized microstructures in a variety of environments, including oxygen-containing pure water and aqueous solutions cont…
Abstract The various pathways of degradation of polyurethane based on MDI and propoxylated trimethylol propane were studied from the analysis of degradation gases sampled at various temperatures during the heating rise. From the beginning of degradation (250°C) to 400°C, we suggest that the main mechanism is the fract…
A crystal structure refineme-nt of a synthetic hafnon, HfSiO4, space group l4llamd with a: 6.5725(7)4, c = 59632(qA,Z: 4,D: 6.97 gmcm-3, produced positional parameters for oxygen ofy = 9.965t(13) and z: 0.1948(14) at R : 0.054. Hafnon has a zircon structure and the similar ionic radii of Hf (0.83A) and Zr (0.844) acco…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMagnetic circular dichroism studies. 60. Substituent-induced sign variation in the magnetic circular dichroism spectra of reduced porphyrins. 1. Spectra and band assignmentsJoseph D. Keegan, Alan M. Stolzenberg, Yu Cheng Lu, Robert E. Linder, Guenter Barth, Albert Moscowitz,…
In the Rietveld method of analysing powder diffraction data, the crystal structure is refined by fitting the entire profile of the diffraction pattern to a calculated profile. There is no intermediate step of extracting structure factors. The method was applied first to diffraction patterns recorded with neutrons at a…
Abstract Poly( p ‐phenyleneterephthalamide) of high molecular weight was obtained when the polycondensation of terephthalic acid and p ‐phenylenediamine was carried out in N ‐methylpyrrolidone (NMP) that contained dissolved CaCl 2 and LiCl in the presence of pyridine. The molecular weight of the polymer obtained varie…
SUMMARY Focusing and correcting the astigmatism of an electron microscope can be time consuming and difficult to achieve accurately. An automatic method of performing these tasks using an on‐line computer system and a digital framestore has been developed. The method is applicable to noisy images in both scanning and…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh-spin-low-spin equilibriums of cobalt(2+) in the terpyridine complexes Co(terpy)2X2.nH2OS. Kremer, W. Henke, and D. ReinenCite this: Inorg. Chem. 1982, 21, 8, 3013–3022Publication Date (Print):August 1, 1982Publication History Published online1 May 2002Published inissue…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDissolution of perfluorinated ion-containing polymersCharles R. Martin, Teresa A. Rhoades, and James A. FergusonCite this: Anal. Chem. 1982, 54, 9, 1639–1641Publication Date (Print):August 1, 1982Publication History Published online1 May 2002Published inissue 1 August 1982ht…
Abstract The pressure‐volume‐temperature (PVT) relationships of bisphenol‐A polycarbonate, polyarylate, and phenoxy were studied at pressures to 1800 kg/cm 2 and in both the glassy and melt states. Earlier data on polysulfone are included in the analysis and discussion of the results. All four polymers contain the bis…
Electronic conductivity and Seebeck coefficients of LaFeO 3 were measured as a function of temperature (1000° to 1400°C) and P ( O 2 ) (10 5 to 10 −13 Pa). Electronic conduction was found to be n‐type in the lower P ( O 2 ) range, and p ‐type in a higher P(O 2 ) range. The calculated carrier mobilities suggest a hoppi…
Two ion‐transport mechanisms are described for ion transport in polyether‐alkali metal salt complexes: an intrahelical jumping process along crystalline (helical) regions of the polymer, and a transport process in the amorphous regions which is dependent on formation of fourfold coordination sites via mutual motion of…
The magnetic free energy in the so-called s-d model where the itinerant d electrons and localised spins coexist is expanded in a power series of the total magnetisation M. The first-order transition observed for DyCo 2 , HoCo 2 and ErCo 2 is explained from the negative values of the coefficient of the M 4 term at T C…
Although it is now fairly well established that defects in amorphous chalcogenide semiconductors are normally charged (D+ and D−), it is demonstrated that neutral defects D0, generated by the reverse reaction of 2D0 → D+ + D−, can be important for a.c. conduction. The contribution to [sgrave](ω, T) from correlated bar…
A small drop placed on a horizontal surface will spread under the action of capillary forces until it reaches an equilibrium position. The rate at which it spreads provides a means for testing certain hypotheses about moving contact lines; namely that there must be slip between the fluid and the solid boundary near th…
Abstract Hydrostatic pressure usually increases the glass transition temperature T g of a polymer glass by decreasing its free volume; if the pressurizing environment is soluble in the polymer, however, one might expect an initial decrease in T g with pressure as the polymer is plasticized by the environment. Just suc…
Abstract Polytrifluoromethylacetylene (PTFMA) was synthesized from trifluoromethylacetylene (TFMA) using a PdCl 2 /DMF catalyst solution or the anionic initiator n ‐butyl lithium. Although PdCl 2 proved to be an effective catalyst for the polymerization of TFMA, long reaction times and poor yields made characterizatio…
A large volume high pressure apparatus has made it possible to grow large single crystals of black phosphorus, P. After converting red P powder into black P under a high pressure of 10 kbar at high temperature, a melt of polycrystalline black P has been gradually solidified to bring about the growth of single crystals…
This article provides a comprehensive review of the theory, practice, and application of electron channeling patterns in the scanning electron microscope. An atlas of indexed channeling maps for the bcc, fcc, diamond cubic, and hcp systems is included with a bibliography of 240 references containing all known publishe…
Standard textbook derivations of the Clausius–Mossotti (Lorentz–Lorenz) relation tend to obscure the physical origin of local-field effects by proceeding from the macroscopic dielectric function of the equivalent homogeneous system to the microscopic parameters of the model. The microscopic and macroscopic aspects can…