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 acyl cyanides 1a — d are prepared from the corresponding acyl chlorides. The Paternó‐Büchi reaction of 1a — f with furan ( 2 ) yields the bicyclic oxetanes 3a — f with an endo / exo ratio varying from 3.5: 1 ( 1a ) to 16: 1 (1 d ). However, in the reaction of the chiral acyl cyanides 1b and 1c , a low chiral induc…
Abstract Elastomeric polymer consisting of poly(oxytetramethylene) segments and viologen units (PTV) was synthesized by the reaction of dicationic living poly(tetrahydrofuran) with 4,4′‐bipyridine at −70°C. The chloride or bromide ion was introduced as the counter anion into the viologen groups of PTV by the treatment…
An investigation of the synthesis by the flux method and the characterization of for cathode ray tube application is presented. In order to obtain an excellent europium distribution inside the matrix, an yttrium‐europium coprecipitated oxide has been used as the raw material. The optimization of firing conditions has…
Although calcium ions are crucial in a variety of bacterial processes, including spore development, reports of calmodulin in procaryotes have been few. We have purified to homogeneity a calmodulinlike protein (CaLP) from sporulating cells of Bacillus subtilis grown in a chemically defined sporulation medium; purificat…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSmall-angle x-ray scattering from dilute solutions of substituted phthalocyaninato-polysiloxanesThomas Sauer and Gerhard WegnerCite this: Macromolecules 1991, 24, 9, 2240–2252Publication Date (Print):April 29, 1991Publication History Published online1 May 2002Published iniss…
If permanent setting of the wool fibre, which occurs during dyeing, can be restricted, the impairment of physical properties is reduced. This can be achieved by adding an oxidising agent, such as potassium bromate or hydrogen peroxide, to the dyebath. Oxidising agents also restrict the extent to which hygral expansion…
Mean depths and profiles of charge distributions in 34 to 40 mu m thick polypropylene films during and after injection of 10 to 40 keV electrons are investigated with the split Faraday cup and the laser-induced pressure pulse methods. For an open front (irradiated) electrode, the mean charge depth increases with time…
Crystalline hydroxyapaiite ultrafine particles were synthesized by hydrothermal treatment of the same powders prepared by mining aqueous ratio of Ca to P (1·67) at room temperature. The relations of the particle size and shape to such operating conditions as hydrothermal temperature, Ca(NO3) 2 concentration, stirring…
Competitive adsorption was studied of deuteriopolystyrene (PS), protio PS, and carboxylic acid terminated PS, from cyclohexane solutions (0.05 or 0.1 mg mL-1) onto a single surface of silicon oxide at 30.0-degrees-C. Surface excess mass of the polymer was measured by infrared spectroscopy in the mode of attenuated tot…
Lysine-2,3-aminomutase purified from Clostridium subterminale SB4 is reported to exhibit an apparent subunit Mr of 48,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the undenatured enzyme exhibits an apparent Mr of 285,000, as determined by electrophoretic mobility and gel permeat…
We report the details of the measurements of the layer compression modulus B and the longitudinal viscosity \tildeη of several thermotropic smectic phases in the frequency range from 10 Hz to 1 kHz. We confirmed for smectic phases having liquidlike layers (including smectic-A, smectic-C and chiral smectic-C phases) th…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure of a novel copper(I) cyanide complex with hexamethylenetetramine, (CuCN)3(C6H12N4)2Fred B. StockerCite this: Inorg. Chem. 1991, 30, 7, 1472–1475Publication Date (Print):April 1, 1991Publication History Published online1 May 2002Published inissue 1 April 199…
Hydrotalcite-like compounds containing Ni(II) and Al(III) cations and with different Ni/Al ratios in the brucite layers have been prepared and studied using FT-IR and V-UV/DR spectroscopies. It has been found that the local environment of the Ni(II) cations is the same in all cases, occupying octahedral holes, but the…
The mechanochemical reactions between CsBr and kaolinite that occur during shaking, grinding at ambient atmosphere (air grinding), and grinding in the presence of a few drops of water (wet grinding), were investigated by photoacoustic and diffuse reflectance infrared spectroscopy and by thermal weight loss. An interca…
The preparation, and conductivity, calorimetric, and electrochemical studies of mixed polymer electrolytes, where MEEP = poly[bis‐(methoxyethoxyethoxide)phosphazene], PPO = poly(propylene oxide) and , are described. The addition of PPO in various proportions to electrolytes significantly improved the latter's dimensio…
Abstract For the purpose of the evaluation of the R—T spin coupling parameter, A RT , an analysis of the Curie temperature is made for the rare earth—transition metal systems R m T n (R rare earth T = Fe, Co; m / n = 1/2, 1/3, 6/23, and 2/17) and some systems of recent and growing interest, such as R 2 T 14 B, RT 11 T…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPersistence length and molecular mass distribution of a thermotropic main-chain liquid-crystal polymerHerbert Kroemer, Rainer Kuhn, Harald Pielartzik, Wilfried Siebke, Volker Eckhardt, and Manfred SchmidtCite this: Macromolecules 1991, 24, 8, 1950–1954Publication Date (Print…
In HV devices such as power cables, electrical stress enhancement can occur at the interface of semiconducting shields (semicon) and polymeric insulation. In this study, points of electrical stress enhancement are simulated by embedding semicon protrusions into the polymer. XLPE with two different concentrations of cr…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComplete carboxylate removal from [Mn12O12(OAc)16(H2O)4].cntdot.2HOAc.cntdot.4H2O) with chlorotrimethylsilane: synthesis and characterization of polymeric (2,2'-bipyridine)trichloromanganese and an improved synthesis of bis(tetraethylammonium) pentachloromanganate(2-)Spiros…
Alignment recovery from damage has been confirmed to occur under an AC electric field, e.g. , 30 V pp ·µm -1 , in antiferroelectric chiral smectic liquid crystal cells of MHPOBC and a related fluorinated compound. The recovery partly results from internal shearing produced by reversible layer switching between bookshe…