On the mechanism of titanium-tartrate catalyzed asymmetric epoxidation
Abstract
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Polymorphism in polar mesogens. II - Theoretical aspects
A unique theoretical framework is shown to interpret not less than seven different smectic phases observed or expected in polar systems. A free energy with two coupled order parameters having a tendency to condense at two incommensurate wavevectors is used.
Metal-Support and Metal-Additive Effects in Catalysis
Preview this article: Metal-Support and Metal-Additive Effects in Catalysis, Page 1 of 1 < Previous page | Next page > /docserver/preview/fulltext/pmr/27/1/pmr0027-0016-1.gif
Porphyrinic molecular metals
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPorphyrinic molecular metalsBrian M. Hoffman and James A. IbersCite this: Acc. Chem. Res. 1983, 16, 1, 15–21Publication Date (Print):January 1, 1983Publication History Published online1 May 2002Published inissue 1 January 1983https://doi.org/10.1021/ar00085a003RIGHTS & PERMI…
Photoreactivity of 9-cyanoanthracene thermally generated inside 9-cyanoanthracene photodimer single crystals
The thermal monomerization of 9-cyanoanthracene photodimer (9CNAD) single crystals has been studied using differential scanning calorimetry (d.s.c.) jointly with emission spectroscopy of cleaved surfaces of partially monomerized 9CNAD single crystals. The first exothermic peak, together with the subsequent peaks, is a…
Simple method for the determination of gypsum, with some observations on the solubilities of gypsum, anhydrite, calcite and dolomite
A rapid method is presented for the determination of gypsum and related minerals in natural and synthetic materials, based on the extraction of calcium from the matrix material using slightly ammoniacal water as a solvent with subsequent complexometric titration of the calcium using EDTA. The results compare reasonabl…
Studies on orientation dependence of dechanneling using rutherford backscattering and characteristic X-ray yields
A peculiarity in the variation of the shape of the dechanneling function with an increase of the tilt angle has been discovered using Rutherford backscattering and characteristic X-ray methods. The discovered effect is due to the known mechanisms of dechanneling and is described qualitatively on the basis of the Focke…
Elevated temperature aging of HIPS
Abstract The effects of aging at 85°C on a rubber‐modified polystyrene (HIPS) have been studied as a function of aging time in both air and nitrogen. Four different types of physical measurements were carried out on the aged samples. These included mechanical relaxation measurements, tensile stress–strain measurements…
Stacking Fault Energy and Deformation Twinning in Copper Crystals
The validity of our nucleation model of deformation twinning previously proposed for fcc metals has been quantitatively examined to determine the stacking fault energy γSF from the twinning stress τT, with particular attention to the orientation dependence of τT of pure copper crystals deformed in tension at 4.2 K. Ma…
Thermal Expansion of Substituted Copper Aluminosilicate Glasses
The effects of various components on the thermal expansion coefficient of low‐expansion Cu 2 O‐Al 2 O 3 ‐SiO 2 glasses were examined. When a component of glass was substituted by another oxide, the expansion coefficient always increased, except for substitution of Al 2 O 3 by B 2 O 3 . This result indicates that the e…
Weldability of modern structural steels in Japan.
The designation HT 50, HT 60, and HT 80 in this paper means the grades
DUST-ABATEMENT MATERIALS: EVALUATION AND SELECTION
The purpose of this paper is to provide (a) a guide for selecting the correct type of dust palliative and application rate for a given situation, (b) information to evaluate alternatives in terms of cost and energy, and (c) application guidelines to ensure the best job for a given situation. Descriptions of current co…
Carbon‐13 NMR microstructural characterization of dichlorocarbene adducts of polybutadiene
Abstract 13 C‐NMR has been used to examine a number of dichlorocarbene adducts of cis ‐ and trans ‐polybutadiene prepared in a two‐phase system. Dichlorocarbene was generated by reaction of aqueous or solid NaOH or KOH with CHCl 3 in the presence of a phase transfer catalyst. Monomer compositions, comonomer sequence l…
Poly(ethylene sulfide): Reevaluation of the electron diffraction structure analysis
The single-crystal electron diffraction data of poly(ethylene sulfide) reported by Hasegawa, Claffey, and Geil have been reinvestigated. Taking into account possible crystal bending effects and dynamical scattering leads to an improved structural model. The final agreement factor of R = 0.21 is considerably better tha…
Electronic Structure of Ion‐Radical Organic Solids and Polyenes
Abstract The electronic structures of organic ion‐radical salts, molecular conductors, and charge‐transfer complexes are described by solid‐state models with one valence state per site. Similar models occur in π‐electron theories of conjugated molecules or in spin Hamiltonians for magnetic insulators. A localized or v…
Über die Kinetik der Fettkristallisation
Abstract Der Verlauf der Fettkristallisation ähnelt dem der Aggregation und Flockulierung von Kolloiden. Früher aus Meßwerten empirisch abgeleitete kinetische Gleichungen für Aggregation und Flockulierung werden auf Meßreihen der Fettkristallisation und der Ausscheidung aus Emulsionen angewandt. Die Meßwerte werden in…
Introduction to Engineering Materials
A text which deals with the basic principles of materials science and technology in a simple, yet thorough manner. This edition includes more worked examples and more detailed information on certain aspects of materials science
Multinuclear variable-temperature nuclear magnetic resonance study of rhodium carbonyl clusters containing encapsulated heteroatoms: ligand and metal polyhedral rearrangements
Variable-temperature multinuclear n.m.r. studies (13C, 13C-{103Rh}, 13C-{31P}, and 31P) are reported for [Rh9E(CO)21]2–, [Rh10E(CO)22]3–(E = P or As), and [Rh12Sb(CO)27]3–. In all cases, complete fluxionality of both the carbonyl and metal polyhedra are observed at high temperatures, and at low temperatures it has bee…
Evolution of glauconite in imperfectly drained sandy soils of the Belgian Campine
Abstract The evolution of glauconite in an imperfectly drained glauconiferous profile with texture B horizon in the Antwerp Campine (Belgium) has been studied by using different techniques (DTA, TGA, XRD and chemical analysis). It has been found that (1) the glauconite sand grains are mechanically broken down into cla…
Development of pore structure in carbon cloth by HNO3 activation
A study has been made of the changes in the adsorptive behaviour of a carbon cloth with aqueous oxidative activation. It has been demonstrated that molecular-sieve action initially present in the cloth can be eliminated by progressive activation but eventually restored after the total pore volume of the cloth has been…