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Molecular Engineering of Liquid Crystal Polymers by Living Polymerization. XXIII. Synthesis and Characterization of AB Block Copolymers Based on ω-[(4-Cyano-4′ -Biphenyl)-oxy]alkyl Vinyl Ether, 1H, 1H, 2H, 2H-Perfluorodecyl Vinyl Ether, and 2-(4-Blphenyloxy)ethyl Vinyl Ether with 1H, 1H, 2H, 2H-Perfluorodecyl Vinyl Ether

Virgil Percec、Myongsoo Lee1992-09-01Journal of Macromolecular Science Part A

This paper describes the synthesis and characterization of AB block copolymers based on ω-[(4-cyano-4′-biphenyl)oxy]alkyl vinyl ether (6-n), with alkyl being ethyl (6-2), propyl (6-3), nonyl (6-9), and undecanyl (6-11), with 1H, 1H, 2H, 2H-perfluorodecyl vinyl ether (CF8), poly[(-6-n)-b-CF8]X/Y (where X/Y refers to th…

Advanced Polymer Synthesis and Characterizationbiodegradable polymer synthesis and propertiesSynthesis and properties of polymers

star-Porphyrazines: synthetic, structural, and spectral investigation of complexes of the polynucleating porphyrazineoctathiolato ligand

Christopher S. Velázquez、Glenn A. Fox、William E. Broderick 等 7 位作者1992-09-01Journal of the American Chemical Society

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTstar-Porphyrazines: synthetic, structural, and spectral investigation of complexes of the polynucleating porphyrazineoctathiolato ligandChristopher S. Velazquez, Glenn A. Fox, William E. Broderick, Kevin A. Andersen, Oren P. Anderson, Anthony G. M. Barrett, and Brian M. Hoff…

Magnetism in coordination complexesPorphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation Mechanisms

Formation of poly(hydroxybutyrate-co-hydroxyvalerate) by Azotobacter vinelandii UWD

W J Page、J. Manchak、B Rudy1992-09-01Applied and Environmental Microbiology

Azotobacter vinelandii UWD formed polyhydroxyalkanoate (PHA) copolymers containing beta-hydroxybutyrate and beta-hydroxyvalerate (HV) when grown in a medium containing glucose as the primary C source and valerate (pentanoate) as a precursor. Copolymer was not formed when propionate was added to the glucose medium but…

Enzyme Catalysis and Immobilizationbiodegradable polymer synthesis and propertiesCarbon dioxide utilization in catalysis

Side-chain liquid-crystalline polyesters for optical information storage

S. Hvilsted、F. Andruzzi、P. S. Ramanujam1992-09-01Optics Letters

We report erasable holographic recording with a resolution of at least 2500 lines/mm on unoriented films of sidechain liquid-crystalline polyesters. Recording energies of approximately 1 J/cm(2) have been used. We have obtained a diffraction efficiency of approximately 30% with polarization recording of holograms. The…

Photonic and Optical DevicesLiquid Crystal Research AdvancementsPhotonic Crystals and Applications

Four homologous domains in the primary structure of GrsB are related to domains in a superfamily of adenylate‐forming enzymes

Kürşad Turgay、Michael Krause、Mohamed A. Marahiel1992-09-01Molecular Microbiology

The entire nucleotide sequence of the Bacillus brevis grsB gene encoding the gramicidin S synthetase 2, which activates and condenses the four amino acids proline, valine, ornithine and leucine has been determined. The gene contains an open reading frame of 13,359 bp which encodes a protein of 4453 amino acids with a…

Protein Structure and DynamicsBacterial Genetics and BiotechnologyEnzyme Structure and Function

The near-infrared spectrum of the guanidinium ion: a local-mode analysis

Ian M. Walker、Paul J. McCarthy1992-09-01Inorganic Chemistry

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe near-infrared spectrum of the guanidinium ion: a local-mode analysisIan M. Walker and Paul J. McCarthyCite this: Inorg. Chem. 1992, 31, 20, 4122–4127Publication Date (Print):September 1, 1992Publication History Published online1 May 2002Published inissue 1 September 1992…

Nonlinear Optical Materials ResearchSpectroscopy and Quantum Chemical StudiesSpectroscopy Techniques in Biomedical and Chemical Research

Synthese und Struktur von Nb0,89Fe0,93Te2 und Ta0,77Fe0,90Te2 / Synthesis and Structure of Nb0.89Fe0.93Te2 and Ta0.77Fe0.90Te2

Jörg Neuhausen、Karl-Ludwig Stork、Elisabeth Potthoff 等 4 位作者1992-09-01Zeitschrift für Naturforschung B

Nb 0.89 Fe 0.93 Te 2 and Ta 0.77 Fe 0.90 Te 2 were prepared by chemical transport reactions. The crystal structures of both compounds were determined using X-ray single crystal methods. The structures of the layer compounds Nb 0.89 Fe 0.93 Te 2 (Pmna, Z = 2, a = 7.951(1) Å, b = 7.241(1) A, c = 6.233(1) Å) and Ta 0.77…

Rare-earth and actinide compoundsIron-based superconductors researchInorganic Chemistry and Materials

Effect of nitrogen content on magnetic properties of Sm/sub 2/Fe/sub 17/N/sub x/ and SmFe/sub 5/N/sub y/ alloys

Tsung‐Shune Chin、Cheng‐Hao Lin、Hao Bai 等 6 位作者1992-09-01IEEE Transactions on Magnetics

Magnetic properties of Sm/sub 2/Fe/sub 17/N/sub x/ and SmFe/sub 5/N/sub y/ with different nitrogen contents are studied. It was found that the magnetocrystalline anisotropy for both Sm/sub 2/Fe/sub 17/N/sub x /and SmFe/sub 5/N/sub y/ alloys changes from easy plane to easy axis at x>0.13 and y>0.07. The 1:5, 1:3, and a…

Magnetic properties of thin filmsMagnetic Properties and ApplicationsMagnetic Properties of Alloys

Chlorophyll adsorption on acid‐activated clay

Çetín Güler、Fatma Tunç1992-09-01Journal of the American Oil Chemists Society

An acid‐activated clay (Çanakkale montmorillonite from Turkey) was used to adsorb chlorophyll from hexane solutions. The phenomenon seems to be mainly driven by the interaction of chlorophyll with acid sites. The adsorption of chlorophyll on Brönsted acid sites was indicated by a characteristic infrared band for the ‐…

Mesoporous Materials and CatalysisClay minerals and soil interactionsAdsorption, diffusion, and thermodynamic properties of materials

Crystal Structure Determination of Ag3CuS2 From Powder X-Ray Diffraction Data

C. L. Baker、FJ Lincoln、AWS Johnson1992-09-01Australian Journal of Chemistry

The crystal structure of Ag3CuS2 has been determined by using X-ray powder diffraction data. The unit cell is tetragonal, a = 8.6705(10), c = 11.7573(18) Å , and the space group is I 41/ amd (141) with Z = 8. A starting model for the structure was derived by using direct methods and difference Fourier cycling from 93…

Magnetic Properties and Synthesis of FerritesX-ray Diffraction in CrystallographyPigment Synthesis and Properties

Assessment of oxidative thermal degradation of crosslinked polyethylene and ethylene propylene rubber cable insulation

K. Anandakumaran、D. J. Stonkus1992-09-01Polymer Engineering and Science

Abstract This paper presents procedures to monitor oxidation degradation of two commonly used cable insulations, crosslinked polyethylene (XLPE) and ethylene propylene rubber (EPR). Since the techniques described require only micro specimens, deterioration of cable insulation can be monitored without destroying the fu…

Polymer crystallization and propertiesHigh voltage insulation and dielectric phenomenaConcrete Corrosion and Durability

Characterization of LiF Using XPS

Chul‐Un Ro、Richard W. Linton1992-09-01Surface Science Spectra

A commercial LiF powder sample was investigated using x-ray photoelectron spectroscopy. Sample preparation included washing in acetone and methanol, pressing into indium foil and gold decoration for charge correction. Measured binding energies were very similar to those previously reported. [See W. E. Morgan, J. R. Va…

X-ray Spectroscopy and Fluorescence AnalysisElectron and X-Ray Spectroscopy TechniquesSurface and Thin Film Phenomena

Thermodynamic properties of the fluid, fcc, and bcc phases of monodisperse charge-stabilized colloidal suspensions within the Yukawa model

Carlos F. Tejero、James F. Lutsko、Jean-Louis Colot 等 4 位作者1992-09-01Physical Review A

The thermodynamic properties of the Yukawa model for colloidal suspensions are determined theoretically from the Rogers-Young integral equation for the fluid phase and from a recently introduced van der Waals--like theory for the solid phases. Very good agreement with the Monte Carlo simulations of Meijer and Frenkel…

Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesThermodynamic properties of mixtures

Gradient-index filters: designing filters with steep skirts, high reflection, and quintic matching layers

H. Fabricius1992-09-01Applied Optics

Gradient-index filters from Lys & Optik were developed on the basis of an inverse Fourier transformation of the desired spectral characteristics. Filter designs with steep skirts and high reflection are possible because of a new correction method where analytical calculations for rugate structures are used as a basis…

Photonic and Optical DevicesLiquid Crystal Research AdvancementsPhotorefractive and Nonlinear Optics

Dynamic Behaviour of Twisted Nematic Liquid Crystals

Kazuaki Tarumi、U. Finkenzeller、Brigitte Schuler Brigitte Schuler1992-09-01Japanese Journal of Applied Physics

Expressions describing the dynamic behaviour in terms of τ on and τ off for twisted nematic structures have been derived through rigorous analysis. The obtained equations are discussed separately for the twisted nematic (TN) and super twisted nematic (STN) cases. Experimentally obtained switching times under various b…

Liquid Crystal Research AdvancementsAdvanced Materials and MechanicsPlant Reproductive Biology

Clinotobermorite, Ca5Si6(O,OH)18·5H2O, a new mineral from Fuka, Okayama Prefecture, Japan

Chiyoko Henmi、Isao Kusachi1992-09-01Mineralogical Magazine

Abstract Clinotobermorite, Ca 5 Si 6 (O,OH) 18 ·5H 2 O, has been found as a vein-forming mineral in gehlenitespurrite skarns at Fuka, Okayama Prefecture. It is associated with tobermorite, plombierite, apophyllite, and calcite. The clinotobermorite is colourless or white and occurs as tabular or acicular crystals. It…

Crystal Structures and PropertiesNuclear materials and radiation effectsChemical Synthesis and Characterization

ac-susceptibility anomaly and magnetic anisotropy ofR2Co17compounds, withR=Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu

X.C. Kou、T. S. Zhao、R. Grössinger 等 4 位作者1992-09-01Physical review. B, Condensed matter

The temperature dependence of the ac susceptibility, \ensuremath{\chi}' and \ensuremath{\chi}'', was measured in the temperature range from 4.2 to 300 K for various polycrystalline compounds ${\mathit{R}}_{2}$${\mathrm{Co}}_{17}$, with R=Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu and single-crystalline compound…

Magnetic properties of thin filmsRare-earth and actinide compoundsMagnetic Properties of Alloys

A comparison of experimental and theoretically derived sensitivity factors for XPS

R. J. Ward、Barry Wood1992-09-01Surface and Interface Analysis

Abstract X‐ray photoelectron spectroscopy sensitivity factors for elements from lithium to zinc have been determined experimentally using standard compounds. These are found to differ quite considerably from those theoretically calculated using Scofield's photoelectric cross‐sections, but are in good agreement with ot…

Advancements in Photolithography TechniquesX-ray Spectroscopy and Fluorescence AnalysisElectron and X-Ray Spectroscopy Techniques

Mixed-metal amorphous and spinel phase oxidation catalysts: characterization by x-ray diffraction, x-ray absorption, electron microscopy, and catalytic studies of systems containing copper, cobalt, and manganese

Paul A. Wright、Srinivasan Natarajan、John Meurig Thomas 等 4 位作者1992-09-01Chemistry of Materials

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMixed-metal amorphous and spinel phase oxidation catalysts: characterization by x-ray diffraction, x-ray absorption, electron microscopy, and catalytic studies of systems containing copper, cobalt, and manganesePaul A. Wright, Srinivasan Natarajan, John M. Thomas, and Pratib…

Catalytic Processes in Materials ScienceMesoporous Materials and CatalysisCatalysis and Oxidation Reactions

Physical interpretation of induction and frequency dependence of power losses in soft magnetic materials

G. Bertotti、M. Pasquale1992-09-01IEEE Transactions on Magnetics

A loss model based on a dynamic generalization of the Preisach hysteresis model, in which the standard Preisach algorithm is coupled to an equation for the rate of change of the flux associated with each elementary Preisach loop, is presented. The model is able to predict loss features not explained by previous treatm…

Magnetic properties of thin filmsElectric Motor Design and AnalysisMagnetic Properties and Applications