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Synthesis and spectroscopy of tert-butylimido complexes of osmium(VI) and ruthenium(VI) porphyrins

Jie‐Sheng Huang、Chi‐Ming Che、Chung‐Kwong Poon1992-01-01Journal of the Chemical Society Chemical Communications

Oxidative deprotonation of [M(P)(NH2But)2][M = Ru, Os; P= porphyrin dianion] gives [Ru(P)(O)(NBut)], [Os(P)(O)(NBut)]and [OS(P)(NBut)2], which are characterised by IR and 1H NMR spectroscopy.

Magnetism in coordination complexesPorphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation Mechanisms

Crystal structures and non-linear optical properties of borane derivatives

M. Lequan、Rose Marie Lequan、Kathleen I. Chane‐Ching 等 9 位作者1992-01-01Journal of Materials Chemistry

[4′-(Dimethylamino)biphenyl-4-yl]dimesitylborane (BNB) and 4-[4′-(Dimethylamino)pnenylazo]phenyldimesityl-borane (BNA) have been investigated by X-ray diffraction; crystallographic data were used to calculate dipole moments in the ground state and the hyperpolarizability coefficient βo was measured by the EFISH techni…

Nonlinear Optical Materials ResearchNonlinear Optical Materials StudiesSolid-state spectroscopy and crystallography

The importance of surface loops for stabilizing an eightfold βα barrel protein

Roman Urfer、Kasper Kirschner1992-01-01Protein Science

An important step in understanding how a protein folds is to determine those regions of the sequence that are critical to both its stability and its folding pathway. We chose phosphoribosyl anthranilate isomerase from Escherichia coli, which is a monomeric representative of the (beta alpha)8 barrel family of proteins,…

Protein Structure and DynamicsEnzyme Structure and FunctionBiochemical and Molecular Research

Investigation of the effect of repetitive voltage surges on epoxy insulation

G.C. Stone、R.G. van Heeswijk、R. Bartnikas1992-01-01IEEE Transactions on Energy Conversion

The aging of epoxy electrical insulation by unipolar, repetitive voltage surges has been investigated to determine whether such surges can precipitate premature failure of high-voltage motor windings and gas insulated switchgear spacers. A full factorial statistical test was devised and performed on 180 pure epoxy ins…

High voltage insulation and dielectric phenomenaPower Transformer Diagnostics and InsulationElectrical Fault Detection and Protection

Characterization of Some Fungal Chitosans

Hiroshi Miyoshi、Kaori Shimura、Kimitsuna Watanabe 等 4 位作者1992-01-01Bioscience Biotechnology and Biochemistry

Chitosan-like materials were extracted from five different fungal cells with NaOH and acetic acid, with the yields varying from 1.2 to 10.4% of the dry fungal cell weight. The degree of N-acetylation of the extracts measured by the colloidal titration method varied considerably depending on the individual species. By…

Nanocomposite Films for Food Packaging

Mathematical, physical and chemical tables

A. J. C. Wilson1992-01-01Medical Entomology and Zoology

Crystal geometry and symmetry Diffraction geometry and its practical realization Preparation and examination of specimens Determination of lattice parameters Interpretation of diffracted intensities Measurement of intensities Refinement of structural parameters Basic structural features Precautions against radiation i…

Material Properties and Applications

Development of High-performance Roll by Continuous Pouring Process for Cladding.

Mitsuo Hashimoto、Seizi Otomo、Kouichiro Yoshida 等 7 位作者1992-01-01ISIJ International

In response to severe quality requirements resulting from remarkable progress in rolling techniques, composite type high performance roll was developed. With the adoption of this method, tough core metal, fine structure and high alloy at shell metal can be obtained with ease. Rolls with shell metal of high speed tool…

Microstructure and Mechanical Properties of SteelsMetallurgy and Material FormingMetal Alloys Wear and Properties

Potassium Accumulation and Corn Yield Related to Potassium Fertilizer Rate and Placement

Joseph R. Heckman、E. J. Kamprath1992-01-01Soil Science Society of America Journal

Abstract Sandy Coastal Plain soils have relatively low reserves of K and may not be able to supply adequate K for intensive corn ( Zea mays L.) production. Field experiments were conducted on Dothan loamy sand (fine‐loamy, siliceous, thermic Plinthic Paleudult) for 3 y to determine K fertilizer rate and placement effe…

Soil Carbon and Nitrogen DynamicsClay minerals and soil interactionsCrop Yield and Soil Fertility

Buoyancy properties of the giant diatom Ethmodiscus

Tracy A. Villareal1992-01-01Journal of Plankton Research

Net-collected Ethmodiscus spp. were examined and found to be capable of positive buoyancy with ascent rates averaging 1.4 m h−1 on individually measured cells, and 0.3 m h−1 using a homogeneous settling technique. These data, together with published reports of positive buoyancy in Rhizosolenia, indicate that upward mo…

Marine and coastal ecosystemsMarine Biology and Ecology ResearchDiatoms and Algae Research

Modeling the Permittivity of Composite Materials with a General Effective Medium Equation

D.S. McLachlan、A. Priou、I. Chênerie 等 5 位作者1992-01-01Journal of Electromagnetic Waves and Applications

The purpose of this paper is to review the multiscattering models for spherical particles, quasistatic mixture laws, effective medium theories, percolation equations, and finally the general effective medium equation (GEM), which are all used for modeling the dielectric properties of complex mixture materials. These a…

High voltage insulation and dielectric phenomenaDielectric materials and actuatorsElectrostatics and Colloid Interactions

Formation and properties of yttrium aluminosilicate glasses

James E. Shelby、S. Michael Minton、Christine E. Lord 等 4 位作者1992-01-01Physics and chemistry of glasses

A large glass forming region, which includes both homogeneous and phase separated glasses, has been found for the yttrium aluminosilicate system. Both the density (2.9 to 3.7 g/cm 3 ) and refractive index (1.54 to 1.72) of these glasses increase dramatically with increasing yttria content, but only slightly with incre…

Luminescence Properties of Advanced MaterialsGlass properties and applicationsPhase-change materials and chalcogenides

An easy access to polyhalogenated metalloporphyrins covalently bound to polymeric supports as efficient catalysts for hydrocarbon oxidation

Pierrette Battioni、J.F. Bartoli、Daniel Mansuy 等 5 位作者1992-01-01Journal of the Chemical Society Chemical Communications

Reaction of silica, montmorillonite and polystyrene bearing amino functions with several polyhalogenated metalloporphyrins gave an easy one-step access to new supported catalysts, owing to a selective nucleophilic substitution of the para-halogen atoms of the porphyrin meso-aryl groups by the polymer amine function; t…

Porphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation MechanismsOxidative Organic Chemistry Reactions

Sol–gel synthesis of barium titanate powders of various compositions

Gerhard Pfaff1992-01-01Journal of Materials Chemistry

The barium titanates BaTiO3, Ba2TiO4, BaTi2O5 and BaTi4O9 can be synthesized by a sol–gel method at low temperatures. The reaction between barium acetate solutions and titanium(IV) isopropoxide leads to the formation of barium titanate gels. The gels can be converted to the barium titanates by drying and calcination.…

Ferroelectric and Piezoelectric MaterialsAdvanced ceramic materials synthesisMicrowave Dielectric Ceramics Synthesis

Improved Method of Producing a Cotton Covered/Polyester Staple-Core Yarn on a Ring Spinning Frame

A.P.S. Sawhney、K.Q. Robert、George F. Ruppenicker 等 4 位作者1992-01-01Textile Research Journal

A new, better method of producing cotton covered/polyester staple-core yarn on a modified ring spinning frame is described. The method uses the concept of twisting a “sandwich” formed by two drafted strands of cotton (rovings) on the outside and a drafted strand of polyester on the inside, thus using a total of three…

Textile materials and evaluationsStructural Analysis and Optimization

On the geometry of Co(II)O6polyhedra in inorganic compounds

Manfred Wildner1992-01-01Zeitschrift für Kristallographie

The shapes of 112 Co(II)O 6 polyhedra in 72 crystal structures of inorganic compounds were analyzed in this study. Most of these polyhedra are significantly distorted from the ideal octahedral symmetry m 3 m , observed point symmetries of the Co(II) sites are: 1(34%); [unk](29%); 2(14%); m (7%); 2/ m , 3(4%); [unk] m…

Concrete and Cement Materials ResearchCrystal Structures and PropertiesX-ray Diffraction in Crystallography

Crystal structure of rhodesite, HK1 −xNax+ 2yCa2 −y{lB,3,2∞2}[Si8O19] · (6 –z) H2O, from three localities and its relation to other silicates with dreier double layers

K.‐F. Hesse、F. Liebau、С. Мерлино1992-01-01Zeitschrift für Kristallographie

Rhodesite from Zeilberg, Unterfranken, Germany ( Z ), from Trinity County, California, USA ( TC ), and from San Venanzo, Rieti, Italy ( SV ), is orthorhombic with space group Pmam . Crystallographic data, given in the order ( Z ), ( TC ), ( SV ), are: a 0 = 23.416(5)/23.444(5)/23.428(20) Å, b 0 = 6.555(1)/6.553(1)/6.5…

Zeolite Catalysis and SynthesisMesoporous Materials and CatalysisCrystal Structures and Properties

Nitrogen dioxide adsorption on deuteroxylated titania (anatase)

Margarita Kantcheva、V. Bushev、Konstantin Hadjiivanov1992-01-01Journal of the Chemical Society Faraday Transactions

The adsorption of No2 on anatase and deuteroxylated TiO2 is investigated by IR spectroscopy. It is established that NO2 reacts with the surface hydroxyl (deuteroxyl) groups of anatase to give nitrates and water molecules (H2O, HOD and D2O) weakly bonded to the nitrates, while on the surface Lewis acidic–basic pairs of…

Catalytic Processes in Materials ScienceCatalysis and Oxidation ReactionsIndustrial Gas Emission Control

Surface-enhanced Raman spectra and gas chemisorption of Langmuir-Blodgett layers of lutetium and ytterbium diphthalocyanines

R. E. Clavijo、D. Battisti、Ricardo F. Aroca 等 5 位作者1992-01-01Langmuir

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSurface-enhanced Raman spectra and gas chemisorption of Langmuir-Blodgett layers of lutetium and ytterbium diphthalocyaninesR. E. Clavijo, D. Battisti, R. Aroca, G. J. Kovacs, and C. A. JenningsCite this: Langmuir 1992, 8, 1, 113–117Publication Date (Print):January 1, 1992Pu…

Hydrocarbon exploration and reservoir analysisPorphyrin and Phthalocyanine ChemistryField-Flow Fractionation Techniques

Passivation of a montmorillonite by the silica created in acid activation

C. Pesquera、F. González、I. Benito 等 6 位作者1992-01-01Journal of Materials Chemistry

The evolution of a Spanish montmorillonite with acid treatment has been studied. With a high concentration of acid, 8 mol dm–3 HCl, there is a break in the normal tendency of the observed behaviour. The silica created at the beginning of the reaction protects the clay structure and impedes subsequent attack. This pass…

Concrete and Cement Materials ResearchMesoporous Materials and CatalysisClay minerals and soil interactions

Introduction to Engineering Materials

Vernon John1992-01-01Palgrave Macmillan UK eBooks

The first edition of this highly successful text aimed, 'to deal with the basic principles of materials science in a simply yet meaningful manner'. The second edition broadened the scope to incorporat

Material Properties and Applications