Materials Literature
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A new ferroelectric crystal from the family of alkylammonium halogenoantimonates and halogenobismuthates, namely (CH3NH3)5Bi2Cl11 (PMACB), was grown. It revealed a second order phase transition at 307 K with a high peak of the dielectric permittivity: ϵ ≃ 5.103 along the c-axis. X-ray diffraction, DSC and dielectric s…
Abstract The kaolin minerals in lateritic weathering profiles on dolerite and granite in Western Australia have been characterized by intercalation tests for halloysites, and also by their particle morphologies. Towards the surface of the profiles there is a decrease in both total kaolin mineral content, and in the ex…
Degradation of the electrical resistance of perovskite‐related dielectrics under voltage–temperature stress is a function of the concentration of the most mobile ionic species, the oxygen vacancy. Sources of oxygen vacancies in simple perovskite oxides are reviewed, and the effects of the compositional complexity of t…
Polyimide films containing up to 3.2 wt. % water (H2 O or D2 O) have been studied by dielectric relaxation (DR) and 2H nuclear magnetic resonance (NMR) spectroscopies. Dielectric loss measurements show the presence of a double peak near 200 K due to water, with two components designated as γ1 and γ2 . The γ2 peak, whi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSurface studies of polymer blends. 3. An ESCA, IR and DSC study of poly(.epsilon.-caprolactone)/poly(vinyl chloride) homopolymer blendsMichael B. Clark Jr., Cindy A. Burkhardt, and Joseph A. Gardella Jr.Cite this: Macromolecules 1989, 22, 12, 4495–4501Publication Date (Print…
ADVERTISEMENT RETURN TO ISSUEPREVArticleUnanticipated redox transformations in gold polyselenides. Isolation and characterization of diselenobis(tetraselenido)diaurate(2-) and undecaselenido(2-)Mercouri G. Kanatzidis and Song Ping HuangCite this: Inorg. Chem. 1989, 28, 26, 4667–4669Publication Date (Print):December 1,…
A commercially available mammary implant containing a soft polyester polyurethane foam shell has been examined for possible diamine hydrolysis products. Fourier Transform Infrared (FT-IR) analysis has shown ester and aromatic structures present in the intact foam shell. Vigorous hydrolysis conditions using NaOH have p…
We have measured the specific heat down to 1.5 K of a collection of high-quality single crystals of \ensuremath{\kappa}-(ET${)}_{2}$Cu(NCS${)}_{2}$ in fields parallel to the crystalline ${a}^{\mathrm{*}}$ direction to 12.5 T. In this first determination of \ensuremath{\gamma}, we find \ensuremath{\gamma} to be 25\ifmm…
Tubulins were purified from the brain tissues of three Antarctic fishes, Notothenia gibberifrons, Notothenia coriiceps neglecta, and Chaenocephalus aceratus, by ion-exchange chromatography and one cycle of temperature-dependent microtubule assembly and disassembly in vitro, and the functional properties of the protein…
Abstract Further symmetrical cerium(IV) bisporphyrinates are prepared from cerium(III) acetylacetonate and tetraphenylporphyrin, tetra‐ p ‐chlorophenylporphyrin, and hexadecahydrotetrabenzporphyrin. In the latter case, a biscerium(III) triple‐decker is also found which is the only product in the case of octamethylporp…
ABSTRACT Short‐term (3 day) diatom colonization of clean ceramic tiles and tiles conditioned with a thin, nonalgal biofilm was examined in fast‐ and slow‐current outdoor experimental stream channels to assess effects of organic conditioning and current regime on diatom colonization. Colonization rates onto uncondition…
Electrochemistry of some β‐Substituted Polythiophenes: Anodic Oxidation, Electrochromism, and Electrochemical Deactivation, Tsai, Eric W., Basak, Sanjay, Ruiz, Jose P., Reynolds, John R., Rajeshwar, Krishnan
The anisotropic displacements of selected rigid groups in bovine ribonuclease A have been refined from X-ray diffraction data by the application of the rigid-body TLS model. The rigid groups chosen were the side chains of tyrosine, histidine and phenylalanine and the planar side chains of aspartic acid, glutamic acid,…
The bifunctional rat liver enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (ATP:D-fructose-6-phosphate 2-phosphotransferase/D-fructose-2,6-bisphosphate 2-phosphohydrolase, EC 2.7.1.105/EC 3.1.3.46) is constructed of two independent catalytic domains. We present evidence that the kinase and bisphosphatase h…
A convenient synthesis of a number of oligomeric thiophcnes and oligomeric methyl-, and ethyl-substituted thiophenes as building blocks for novel conducting polymers is reported. The synthesis is based on a NiCl2(dppp) (dppp = Ph2PCH2CH2CH2;PPh2) catalyzed coupling reaction between appropriately substituted bromothiop…
Although many proteins are known to be regulated via reversible phosphorylation, little is known about the mechanism by which the covalent modification of seryl, threonyl, or tyrosyl residues alters the activities of the target systems. To address this question, modified versions of Bacillus subtilus HPr, a protein co…
The structure of chemisorbed CO on the steps of Pt(112) {Pt[3(111)×(001)]} was monitored as a function of coverage by the digital electron stimulated desorption-ion angular distribution method (ESDIAD), digital low-energy electron diffraction (LEED), and temperature-programmed desorption (TPD). The ESDIAD method appli…
C 3 H 7 NO cristallise dans Pnam avec affinement a 110 K jusqu'a 0,034. Existence de liaisons hydrogene qui ont un effet significatif sur la conformation de la molecule
Rod-shaped scattering, referred to as crystal truncation rod (CTR) scattering in X-ray diffraction, can also be observed in optical diffraction patterns obtained from the surface profile image of high-resolution electron micrographs. The characteristics of the CTR scattering are shown to be in agreement with those obs…
A drastic drop of the electrical resistivity was observed on a ferroelectric insulator BaTiO 3 surface, after KrFlaser irradiation in air at atmospheric pressure. The temperature dependence of the resistivity was employed to demonstrate semiconducting behavior. Such behavior was seen when the resistance was measured i…