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。
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation of substituted tetrabenzotriazaporphyrins and a tetranaphthotriazaporphyrin: a route to mono-meso-substituted phthalocyanine analogsClifford C. Leznoff and Neil B. McKeownCite this: J. Org. Chem. 1990, 55, 7, 2186–2190Publication Date (Print):March 1, 1990Publica…
Based on expressions for transient three-phase short-circuit current, the formulas for radial and axial electromagnetic forces acting on transformer windings are derived. The short-circuit forces, include three components: DC component, fundamental-frequency component, and double-frequency component. Using a 17000-kVA…
The smectic-A (Sm-A) to chiral-smectic-C transition has been studied by high-resolution ac calorimetry in seven mixtures of two chiral esters of 2,5-diphenyl pyrimidine (2f+3f) over the range 38.72\ensuremath{\le}${\mathit{X}}_{2\mathit{f}}$\ensuremath{\le}65.30, where ${\mathit{X}}_{2\mathit{f}}$ is the mole percent…
A similar phenomenon of continuation beyond a blow-up point has been found in unsteady Hele-Shaw problems and for one-parameter families of two-dimensional obstacle problems in [23, 21}.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 NMR study of poly(2,6-dimethyl-1,4-phenylene oxide)s. Sites of amine incorporationD. M. White and S. A. NyeCite this: Macromolecules 1990, 23, 5, 1318–1329Publication Date (Print):March 1, 1990Publication History Published online1 May 2002Published inissue 1 March…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHighly oriented low-modulus materials from liquid-crystalline polymers: the ultimate penalty for solubilizing alkyl side chainsAaldrik R. Postema, K. Liou, Fred Wudl, and Paul SmithCite this: Macromolecules 1990, 23, 6, 1842–1845Publication Date (Print):March 1, 1990Publicat…
In order to estimate the influence of occlusion and sweating on forearm and vulvar skin surface water loss (SSWL), both were measured simultaneously and continuously for 30 min in 8 healthy women. Vulvar SSWL decreased significantly during the measuring period from 24.9 +/- 5.2 gm-2 h-1 (mean +/- standard error of the…
Dimethyltitanocene is an excellent catalyst for the redistribution of alkoxy- and siloxyhydrosilanes. The redistribution reactions of triethoxysilane, diethoxymethylsilane, 1,3,5,7-tetramethylcyclotetrasiloxane, pentamethyldisiloxane, and H—(SiMe 2 O) n —SiMe 2 H (n = 1 to 3) are described. The mechanism of these reac…
SUMMARY The variation in the solubility of aluminium in some acid soils of south‐eastern Australia has been investigated. The hypothesis was that leaching of silicic acid influenced the extent of clay decomposition, and hence aluminium solubility, in accord with Le Chatelier's principle. In lower rainfall areas (<…
Abstract The mechanisms of photooxidation usually envisaged, are perfected by taking into account photoreactions of peroxy radicals. They involve interaction of a peroxy radical with the polymer to yield a hydroperoxy radical and a pair of macroradicals. After peroxidation, this pair will usually undergo bimolecular t…
Quasi-periodicity under certain conditions of the dependence of grating properties on groove depth is explained from the point of view of energy flow distribution (EFD). The formation of curls in flow maps is followed as a function of the groove depth h for two general types of gratings having one or two propagating d…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and packing in crystalline aliphatic polyestersWen Bin Liau and Richard H. BoydCite this: Macromolecules 1990, 23, 5, 1531–1539Publication Date (Print):March 1, 1990Publication History Published online1 May 2002Published inissue 1 March 1990https://pubs.acs.org/doi…
Abstract Structure‐properties relationships of poly(ether/ester)s (PEEs) 1 based on poly(butylene terephthalate) (PBT) and poly(ethylene glycol) (PEG) are studied. By varying the length of the soft segments (PEG) of molecular weights 600, 1000 and 2000) two series of PEEs are obtained, (i) with constant mole ratio PBT…
Abstract Micropore distribution and effective size of the channels of natural sepiolite from Turkey were measured by the BET method. Before the BET measurement, the samples were treated under a water vapour atmosphere at various pressures to fill progressively the sepiolite micropores with water. The surface areas mea…
Abstract The relation between the structure of the Solution SBR and the dynamic properties of carbon-black-filled SBR vulcanizates have been studied. The results obtained were as follows: 1. The hysteresis of the Solution-SBR vulcanizates was reduced markedly by the introduction of tin—carbon bonds at the polymer chai…
In order to analyze the effects of Al and Fe coatings on mineral grains, montmorillonite (Mt), kaolinite (Kt), and deferrated strongly weathered soils (T6B and T7B) were artificially coated with 2, 6, 10% of Fe or Al hydroxides. Changes in the values of the zero point of charge (ZPC), specific surface area (SSA), and…
Abstract The HALS stabilization mechanisms usually envisaged do not explain the experimental facts. New mechanisms are proposed instead. They include quenching of excited charge‐transfer complexes (CTC) polymer‐oxygen by CTC HALS‐oxygen. In addition, the formation of CTC between peroxy radicals and NH‐HALS is of prime…
In the present paper, a study has been made of carbon dissolution from industrial cokes and specially treated cokes in hot metal. With these results obtained together with earlier investigations, a model is now presented, which attempts to explain carbon pick‐up from coke by hot metal. Factors relating to hot metal, c…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect evidence for transesterification and randomization in a mixture of homopolyesters of poly(4-hydroxybenzoic acid) and poly(6-hydroxy-2-naphthoic acid) above 450.degree.A. Muhlebach, James Economy, R. D. Johnson, T. Karis, and J. LyerlaCite this: Macromolecules 1990, 23…
Abstract Chemical characteristics of glauconite and ferric illite derived from alteration of K-feldspar in three Proterozoic formations of India are studied. The phases show widely varying octahedral and tetrahedral cation contents, but K-content is nearly constant. Co-existence of glauconite and ferric illite is inte…