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。
The effects of doping and uniaxial stress on the structural and magnetic properties of VO2 are reviewed. Important electron-electron correlation effects are deduced : (i) in the metallic phase from the results obtained V1-xNbxO2 alloys, (ii) in the insulating phases of pure VO2 at ambiant pressure (M1), under uniaxial…
Abstract Es wird über die Darstellung, die Eigenschaften und die röntgenographische Untersuchung von Cu 2 BaSnS 4 (A) und Ag 2 BaSnS 4 (B) berichtet. (A) kristallisiert trigonal, — Raumgruppe C –P3 1 mit a = 6,36 7 und c = 15,83 3 Å — und ist mit Cu 2 SrSnS 4 [1] isotyp. (B) hat eine orthorhombische Elementarzelle: a…
Abstract A non‐Gaussian theory of the stress‐induced crystallization of polymeric networks is presented. It is predicted that for uniaxial extension of crosslinked polyethylene, a perfectly oriented, extended‐chain crystal is formed initially, changing to one‐fold crystal oriented perpendicular to the stretch directio…
Abstract The reaction of cellulose with phosphorous acid in molten urea afforded a white, water‐soluble product. The product was a monoester of phosphorous acid, and all the phosphorus residues were in phosphonic form, i.e., cellulose phosphonate. Quantitative addition of acrylonitrile to the PH bonds in cellulose ph…
Explicit expressions are obtained for the line energy of straight dislocations in orthorhombic polyethylene crystals. It is found that the ⟨0, 0, c⟩ screw dislocation is the perfect dislocation with the lowest line energy whilst the ⟨0, 0, c⟩ edge has negative line tension and is therefore unstable. The possible disso…
Following the dramatic impact of the first protein structure determinations, the field of macromolecular crystallography has expanded with ever-increasing rapidity. In many cases the techniques used are the same as those pioneered by Perutz and Kendrew and their disciples, but the preoccupation has shifted from method…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and Moessbauer spectra of octaethylporphyrin ferrous complexesDavid Dolphin, John R. Sams, Tsang Bik Tsin, and Kit L. WongCite this: J. Am. Chem. Soc. 1976, 98, 22, 6970–6975Publication Date (Print):October 1, 1976Publication History Published online1 May 2002Publi…
The density of 8CB has been measured between 28 and 5O°C and the volume change at the SA-N and N-I transitions determined. The SA-N appears to be first order. The implications of the results are discussed with respect to the molecular packing in the unusual structure of the cyanobiphenyls in which the layer spacing is…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLow-temperature electron spin resonance spectra of heteropoly blues derived from some 1:12 and 2:18 molybdates and tungstatesRonald A. Prados and Michael T. PopeCite this: Inorg. Chem. 1976, 15, 10, 2547–2553Publication Date (Print):October 1, 1976Publication History Publish…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNitrogen charge distributions in free-base porphyrins, metalloporphyrins, and their reduced analogs observed by x-ray photoelectron spectroscopyD. H. Karweik and N. WinogradCite this: Inorg. Chem. 1976, 15, 10, 2336–2342Publication Date (Print):October 1, 1976Publication His…
Abstract Structure is taken as the main theme in outlining the mechanical properties of polymer composites. Examples of two‐component polymer systems are selected from the literature showing their morphology, as evidenced from electron micrographs, and their corresponding mechanical properties, as evidenced by dynamic…
In order to analyze experimental data of torque measurements for magnetic thin films, a (L/H)2-vs-L plot is proposed, where L represents the torque of a film in a field of H whose direction is 45° to the film plane. The saturation magnetization M and perpendicular anisotropy energy K⊥ are obtained without any approxim…
Twenty-two proteins available to this laboratory were examined for their ability to crystallize from polyethylene glycol (PEG). Of the 22, 8 had been crystallized previously by conventional means and the remainder had yielded no crystals by other methods. Using a single broad screen with four different concentrations…
The spin-Peierls transition is considered as a progressive spin-lattice dimerization occurring below a transition temperature in a system of one-dimensional antiferromagnetic Heisenberg chains. In the simplest theories, the transition is second order and the ground state is a singlet with a magnetic gap. The historica…
Progress in the field of reflective multilayer coatings for the wavelength region between 50 A and 2000 A is reviewed. All the coatings contain absorbing materials, absorption losses are minimized by positioning strongly absorbing materials into the nodes of the standing wave inside the coating. Above lambda = 1200 A,…
Monte Carlo results are presented for the free energy and dielectric constant of systems of permanent dipoles disposed on the sites of simple cubic and face-centred cubic lattices as functions of the parameter ϑ = μ2ρ/kT. Alternative schemes are considered for taking account of the long-range character of the dipolar…
The hexagonal cell dimensions a and c of 2H-MoS2, 2H-MoSe2 and 2H-WSe2 have been measured over the temperature range 20 to 800 °C. In all three compounds a and c increased non-linearly with temperature, the linear thermal expansion coefficient of c being greater than that of a. Above 500°C the compounds begin to decom…
ABSTRACT Determinations were made of several physical properties of the viscid and frame silks of the orb-webs built by the spider Araneus sericatus (Cl.). Both types of silk show a breaking stress of approximately 1 GN/m2 and an initial resilience of approximately 0·35. The breaking extension ratio of viscid silk (λ…
Abstract not Available.
Procedures for the preparation of soluble collagen from rat skin and tail tendon were reviewed and revised to permit the preparation of native monomeric collagen with intact nonhelical ends. The degree of intactness was estimated from the tyrosine content, which is present only in the nonhelical ends, and by mobility…