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 ISSUEPREVArticleNEXTOptical electron-transfer transitions in polynuclear complexes of the type X(NH3)4RuNCRu(bpy)2CNRu(NH3)4Ym+ (X = NH3, py; Y = NH3, py; m = 4-6)Carlo Alberto Bignozzi, Carmen Paradisi, Sergio Roffia, and Franco ScandolaCite this: Inorg. Chem. 1988, 27, 2, 408–414Publication D…
Donor‐doped, stoichiometric BaTiO 3 sintered at 1350°C for 1 h exhibits a maximum room‐temperature conductivity at [La 3+ ]∼0.15 mol%. Elements of lower valence than Ba 2+ or Ti 4+ , when incorporated into semiconducting BaTiO 3 , are regarded as poisoning impurities, i.e., acceptors. They tend to increase the room‐te…
ABSTRACT Studies were carried out on the solubility and permeability of limonene vapor in two cereal package liners. The effect of limonene partial pressure on the permeation rate and permeability coefficient was determined over a concentration range of 0.3 to 7 ppm (wt/v). The equilibrium sorption concentration and s…
Abstract Dilation of polysulfone (PSUL) and crystalline poly(ethylene terephthalate) (PET) films accompanying sorption of carbon dioxide is measured by a cathetometer under high pressure up to 50 atm over the temperature range of 35–65°C. Sorptive dilation isotherms of PSUL are concave and convex to the pressure and c…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMetal complexes with tetrapyrrole ligands. 46. Europium(III) bis(octaethylporphyrinate), a lanthanoid porphyrin sandwich with porphyrin rings in different oxidation states, and dieuropium(III) tris(octaethylporphyrinate)Johann W. Buchler, Andre De Cian, Jean Fischer, Martina…
The thickness dependence of the nematic–isotropic transition of a liquidcrystalline thin film bounded by strongly ordering or disordering substrates has been studied through birefringence measurements. In accordance with the thermodynamic Kelvin equation, the transition temperature was found to shift from the bulk tra…
Abstract Poly(2,5-pyridinediyl) was prepared by dehalogenation polycondensation of 2,5-dibromopyridine with Ni(0)-complexes. The polymer was soluble in formic acid, and the solution showed λmax at about 370 nm and large degree of depolarization.
The fracture surfaces of a series of CaO‐doped polycrystalline aluminas are examined by Auger electron spectroscopy (AES) and scanning electron microscopy (SEM). The AES results show a maximum in the detected calcium over the range of materials, whereas the SEM observations show a monotonic increase in the proportion…
The shear-thickening property observed in ionomer solutions is discussed. Scattering and dynamic modulus data suggest that the ionic groups cluster into multiplets and that these control the relaxation of stress. A simple mechanism for shear thickening is described ; it leads to the expectation that these clusters mus…
Using synthetic manganese porphyrin complexes with an imidazole or a pyridine ligand covalently attached to the macrocycle, we report the control of the reaction rate, product selectivity, and stereoselectivity by the axial ligand trans to the active site of the catalyst. The results clearly illustrate the proximal ef…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn unusually stable manganese(II)manganese(III) complex with novel EPR spectra: synthesis, structure, magnetism, and EPR analysisHsiu Rong. Chang, Habibe. Diril, Mark J. Nilges, Xiaohua. Zhang, Joseph A. Potenza, Harvey J. Schugar, David N. Hendrickson, and Stephan S. IsiedC…
The purpose of the paper is to give the theoretical basis for the design and optimization of X-UV interference mirrors. To achieve this original results are presented and the « state of the art » methods are reviewed. A new formulation of the Bragg conditions is obtained on the basis of the « Hill method » to solve th…
This study investigated the effect of protective clothing ensembles (against chemical agent and cold weather) on the energy cost of a bench stepping task (20 steps/min on a 0·305 m high bench). Twelve male soldiers (mean age 25·5 years; mean weight 75·4 kg) performed the task at an ambient temperature of 10°C in each…
The first observation of a new director orientation within nematic droplets is reported. This orientation consists of the nematic director field arranged concentrically around a central core running through the center of the droplet, with tangential alignment of the nematic at the droplet surface. It is shown that for…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExtremely weak magnetic exchange interactions in terpy-containing copper(II) dimer. Crystal and molecular structure of Cu(terpy)(CA).H2O and [Cu2(terpy)2(CA)](PF6)2 complexes (terpy = 2,2':6',2"-terpyridine, CA = dianion of chloranilic acid)Jose V. Folgado, Rafael Ibanez, Eu…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTotal asymmetric transformations at interfaces with centrosymmetric crystals: role of hydrophobic and kinetic effects in the crystallization of the system glycine/.alpha.-amino acidsI. Weissbuch, L. Addadi, L. Leiserowitz, and M. LahavCite this: J. Am. Chem. Soc. 1988, 110,…
U.v. photolysis of homogeneous solutions containing tetrakis(tetrabutylammonium)decatungstate(VI), [NBu4]4[W10O32], and olefins in acetonitrile leads to dimerization of olefins via abstraction of an allyl hydrogen, with accompanying formation of reduced decatungstates, up to two electrons. Coexistence of heterogeneous…
The core structure of hedgehog point disclinations in magnetic and nematic liquid crystal systems is investigated within Landau theory. Exact spherically symmetric solutions are found, with isotropic cores. In the nematic hedgehog the solution is uniaxial everywhere. Nematic hedgehogs are very much larger than magneti…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTContrasting one- and two-cation binding behavior in syn- and anti-anthraquinone bibracchial podand (BiP) mono- and dianions assessed by cyclic voltammetry and electron paramagnetic resonance spectroscopyMilagros. Delgado, Deborah A. Gustowski, Hyunsook K. Yoo, Vincent J. Gat…
In Escherichia coli, a single operon encodes the metabolic and regulatory enzymes of the glyoxylate bypass. The metabolic enzymes, isocitrate lyase and malate synthase, are expressed from aceA and aceB, and the regulatory enzyme, isocitrate dehydrogenase kinase/phosphatase, is expressed from aceK. We cloned this opero…