Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
An extensive study of the 51 V NMR in VO 2 has been made between 4.2 K and 600 K, particularly laying stress on the analysis of the temperature dependence of the nuclear relaxation rate 1/ T 1 . In the metallic (M) phase ( T > T t =340 K) an exchange-enhanced Korringa relaxation process for 1/ T 1 is observed and the…
The electrical conductivity of sintered pellets of nickel–nickel oxide mixtures of various compositions has been measured as a function of temperature in the range 700–1000 °C. The electrical conductivity of nickel oxide single crystals in air as well as in oxygen pressures corresponding to nickel–nickel oxide equilib…
Gold, platinum and tungsten films were deposited by low energy input (7 mA, 450 V), or high deposition rate (80 mA, 1500 V), diode sputter coating and by ion beam sputter coating. Film structures on Formvar coated grids and on the surface of coated erythrocytes, resin embedded, sectioned, and recorded at high magnific…
Abstract New silicon‐containing polyimides have been prepared by the reaction of pyromellitic dianhydride (PMDA) and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) with organosilicon diisocyanates having the following general structure: magnified image where R 1 = R 2 = CH 3 and C 6 H 5 . Thermal propertie…
A formulation of the three dimensional eddy current problem is presented. The magnetic vector potential is used in regions with source currents and conducting material and the total magnetic scalar potential is employed elsewhere. The continuity of the normal component of flux density and tangential component of field…
Abstract With the use of solid state carbon-13 NMR, changes in the structure of natural rubber and cis -polybutadiene were observed spectroscopically. Cis-trans conversion has been shown to occur in the naturaal rubber by the rearrangement of the allylic free radical. At least four structurally different methyl groups…
A theoretical approach is presented for predicting the strengthening of brittle materials subjected to a residual stress distribution represented by a polynomial series. In the approach, the stress intensity factor for a surface crack is derived incorporating the effect of crack closure. The crack‐closure distance is…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe strain energy of diphenylcyclopropenone: a reexaminationArthur Greenberg, Reginald P. T. Tomkins, Mark Dobrovolny, and Joel F. LiebmanCite this: J. Am. Chem. Soc. 1983, 105, 23, 6855–6858Publication Date (Print):November 1, 1983Publication History Published online1 May 2…
A model for Schottky barrier‐like heterojunction photoelectrodes is presented. This model allows the calculation of the current‐voltage curves for such electrodes under different conditions of illumination and electrochemical charge transfer. SnO 2 ‐ coated n‐type Si electrodes in contact with the redox systems K 3 /…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRadical anions and radical trianions of tetracyanoarenoquinodimethanes. An ESR and ENDOR studyFabian Gerson, Rene Heckendorn, Dwaine O. Cowan, Arawinda M. Kini, and McRae MaxfieldCite this: J. Am. Chem. Soc. 1983, 105, 24, 7017–7023Publication Date (Print):November 1, 1983Pu…
This paper is related to a new method recently proposed by Australian authors for the study of lamellar gratings in electromagnetic theory. The present authors first recall the principle of this method and make some theoretical comments. Then they describe how numerical difficulties which appear in normal incidence an…
Experimental evidence from the literature is presented to demonstrate that adsorption of chemical substances in soils and related materials is significantly influenced by competition from other adsorbing chemicals. Both organic and inorganic ions are capable of competing for adsorption sites on soils. Potential compet…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMembrane-filter, direct-transfer technique for the analysis of asbestos fibers or other inorganic particles by transmission electron microscopyGarry J. Burdett and Anthony P. RoodCite this: Environ. Sci. Technol. 1983, 17, 11, 643–648Publication Date (Print):November 1, 1983…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSulfide bronzes: preparation and characterization of (RE)Pd3S4 (RE = Rare Earth)Douglas A. Keszler and James A. IbersCite this: Inorg. Chem. 1983, 22, 23, 3366–3367Publication Date (Print):November 1, 1983Publication History Published online1 May 2002Published inissue 1 Nove…
The intermediate phase (IP) between α and β phases of quartz, which has been reported previously by the present authors, was studied by a fine-beam X-ray Laue method. Then, one could find satellite reflections. The analysis shows that IP has a sinusoidal and displacive modulated structure which is characterized by 6 w…
A new route for synthesis of unsymmetrically substituted porphyrins is described. The route follows the earlier approach through pyrromethanes, tripyrrin hydrobromides, and a,c-biladiene dihydrobromides, except that the pyrromethane intermediate is elongated in an initially “clockwise” direction to give a benzyl tripy…
Simultaneous mechanical and molecular characterization of a composite system has been attempted with respect to the interface. The mechanical properties of an E-glass cloth/ y-methacryloxypropyltrimethoxysilane (γ-MPS)/bisphenol-A-fumarate polyester resin composite system were studied as a function of the amount of γ-…
The rate of olefin oxygenation catalyzed by synthetic metalloporphyrins is examined, employing sodium hypochlorite as the oxygen atom source. The rate of epoxidation and the stability of the catalyst are shown to be dependent on the nature of the axial ligand employed. A rationale for this effect is presented and anal…
Abstract Poly( p ‐phenylene), poly(2,6‐naphthylene), poly(2,7‐naphthylene), poly(1,5‐naphthylene), and poly(1,4‐naphthylene) were prepared by nickel‐catalyzed polycondensation of Grignard reagents from the corresponding dibromides. The polymers were annealed in vacuo. Doping with SbF 5 markedly increase the conductivi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelective ring-opening polymerization of di-O-methylated and di-O-benzylated 1,4-anhydro-.alpha.-D-ribopyranoses and structure proof of synthetic cellulose-type polysaccharide (1 .fwdarw. 4)-.beta.-D-ribopyranan and (1 .fwdarw. 5)-.alpha.-D-ribofurananToshiyuki Uryu, Junichi…