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Nonsymmetric Deformation Behavior of Lead Zirconate Titanate Determined in Bending Tests

T. Fett、D. Münz、G. Thun1998-01-01Journal of the American Ceramic Society

Soft lead zirconate titanate (PZT) ceramics exhibit a nonsymmetric deformation behavior, where the tensile strains exceed the compressive strains for a given stress level. This phenomenon affects the strains in bending tests. In addition to the normally determined bending strain that is measured by the curvature of a…

Advanced ceramic materials synthesisRock Mechanics and ModelingHigh-Velocity Impact and Material Behavior

Direct Inversion of Dynamical Electron Diffraction Patterns to Structure Factors

John C. H. Spence1998-01-01Acta Crystallographica Section A Foundations of Crystallography

An exact nonperturbative inversion method is described for transmission electron diffraction which allows crystal structure factors to be obtained directly from the intensities of multiply scattered Bragg beams. These amplitudes are required at several thicknesses (or electron beam energies) and orientations of a thin…

Quasicrystal Structures and PropertiesX-ray Diffraction in CrystallographyCrystallography and Radiation Phenomena

Synthesis of novel monoazo benzotriazole dyes specifically for surface enhanced resonance Raman scattering‡

Duncan Graham、Gerard McAnally、Joanna C. Jones 等 4 位作者1998-01-01Chemical Communications

Surface enhanced resonance Raman scattering (SERRS) has considerable potential as an ultra-sensitive analytical technique; for the first time the synthesis of specific dye ligands designed to overcome major problems in obtaining reliable SERRS is described.

Gold and Silver Nanoparticles Synthesis and ApplicationsAdvanced biosensing and bioanalysis techniquesAdvanced Nanomaterials in Catalysis

Reversing the stereochemistry of a Diels–Alder reaction: use of metalloporphyrin oligomers to control transition state stability

Zöe Clyde-Watson、Anton Vidal‐Ferran、Lance J. Twyman 等 9 位作者1998-01-01New Journal of Chemistry

A cyclic Zn-porphyrin trimer with ethyne and butadiyne links stabilises the thermodynamically disfavoured endo transition state and product of a reversible Diels–Alder reaction; at 30°C the endo adduct is formed rapidly and almost exclusively. Linear porphyrin dimers containing ethyne or butadiyne links show related s…

Porphyrin and Phthalocyanine ChemistryMolecular Junctions and NanostructuresSurface Chemistry and Catalysis

Sulfur dioxide gas detection by reversible η1-SO2–Pt bond formation as a novel application for periphery functionalised metallo-dendrimers‡

Martin Albrecht、Robert A. Gossage、Gerard van Koten 等 6 位作者1998-01-01Chemical Communications

Multimetallics such as dendrimer 3 which are functionalised at their periphery with platinum(II) metal centres reversibly absorb SO2 to yield macromolecules with significantly enhanced solubility characteristics and drastic colour changes; properties which make these compounds highly active sensors for milligram quant…

Gas Sensing Nanomaterials and SensorsLuminescence and Fluorescent MaterialsDendrimers and Hyperbranched Polymers

Quantized aggregation phenomena in II‐VI‐semiconductor colloids

V. Ptatschek、Thomas Schmidt、Martin Lerch 等 9 位作者1998-01-01Berichte der Bunsengesellschaft für physikalische Chemie

Abstract Highly concentrated 0.5 M II‐VI semiconductor quantum dot solutions for coating applications can be synthesized employing chalcogenolysis and condensation of functionalized cluster‐like cadmium and zinc ethoxy‐acetates. Furthermore, in nucleation studies on CdSe solutions, new magic clusters between 0.42 and…

Quantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin FilmsSpectroscopy and Quantum Chemical Studies

Au@SiO2 colloids: effect of temperature on the surface plasmon absorption

Luis M. Liz‐Marzán、Paul Mulvaney1998-01-01New Journal of Chemistry

The effect of temperature on the surface plasmon absorption of Au@SiO2 particles has been measured from 14 to 70°C in aqueous solutions and from 16 to 50°C in ethanolic solutions. The particles remain completely dispersed at elevated temperatures because of the silica shell. As the temperature is increased, there is p…

Gold and Silver Nanoparticles Synthesis and ApplicationsElectrochemical Analysis and ApplicationsNonlinear Optical Materials Studies

Formation of Sterilized Edible Films Based on Caseinates: Effects of Calcium and Plasticizers

Emna Mezgheni、G. D’Aprano、Monique Lacroix1998-01-01Journal of Agricultural and Food Chemistry

gamma-Irradiation was used to produce free-standing sterilized edible films based on caseinate. The effects of calcium ions (Ca(2+)) and two plasticizers, namely propylene glycol (PG) and triethylene glycol (TEG), were investigated, as was the effect of the irradiation on both the gel formation and mechanical properti…

Nanocomposite Films for Food Packagingbiodegradable polymer synthesis and propertiesElectrospun Nanofibers in Biomedical Applications

Condition assessment of EPDM composite insulators using FTIR spectroscopy

P. Blackmore、D. Birtwhistle、Gregory Cash 等 4 位作者1998-01-01IEEE Transactions on Dielectrics and Electrical Insulation

Two new sampling and analysis techniques for assessing the condition of EPDM (ethylene-propylene diene monomer) composite insulators are presented. Polymer oxidation is assessed by removing small amounts of surface polymer by swabbing with xylene and analyzing this material by FTIR (Fourier transform infrared) emissio…

High voltage insulation and dielectric phenomenaPower Transformer Diagnostics and InsulationElectron and X-Ray Spectroscopy Techniques

Synthesis and properties of novel tetrathiafulvalene vinylogues

Yoshiro Yamashita、Masaaki Tomura、Md. Badruz Zaman1998-01-01Chemical Communications

The cation radical states of novel TTF vinylogues with o-substituted phenyl groups at the vinyl positions are thermodynamically stable, and X-ray analyses of the cation radical salts have revealed the planar structures of the TTF vinylogue parts and unique crystal structures.

Magnetism in coordination complexesOrganic and Molecular Conductors ResearchSolid-state spectroscopy and crystallography

Rapid synthesis of dendrimers based on calix[4]resorcinarenes

Yoshitaka Yamakawa、Mitsuru Ueda、Ritsuko Nagahata 等 5 位作者1998-01-01Journal of the Chemical Society Perkin Transactions 1

Calix[4]resorcinarenes are phenolic macrocyclic compounds, and readily available from resorcinols and aldehydes. We were interested in calix[4]resorcinarenes as highly functionalized core molecules for the rapid synthesis of dendrimers because of their ease of synthesis and because they are less affected by steric con…

Supramolecular Chemistry and ComplexesRNA Interference and Gene DeliveryDendrimers and Hyperbranched Polymers

Disk-like liquid crystals of transition metal complexes Part 21.‡—Critical molecular structure change from columnar to lamellarliquid crystal in bis(diphenylglyoximato)nickel(II)-based complexes

Kazuchika Ohta、Ryuji Higashi、Mayumi Ikejima 等 5 位作者1998-01-01Journal of Materials Chemistry

The critical molecular structure change from columnar to lamellar mesophases in bis(diphenylglyoximato)nickel(ii)-based complexes has been investigated. When the number of the long chains surrounding the core complex part was reduced from eight to four, the mesophase changes its structure from columnar Colhd to novel…

Liquid Crystal Research AdvancementsSurfactants and Colloidal SystemsMolecular spectroscopy and chirality

Theoretical search for new ferromagnetically coupled transition metal complexes

Eliseo Ruíz、Santiago Álvarez1998-01-01Chemical Communications

Computational methods based on the density functional theory have been employed in the search for new ferromagnetic molecules and several compounds are predicted to exhibit stronger ferromagnetic coupling than the known hydroxo-bridged complexes, especially remarkable is the very strong coupling predicted for oxo-brid…

Metal complexes synthesis and propertiesMagnetism in coordination complexesMetal-Catalyzed Oxygenation Mechanisms

Versatile Action of Escherichia coli ClpXP as Protease or Molecular Chaperone for Bacteriophage Mu Transposition

Jessica M. Jones、David J. Welty、Hiroshi Nakai1998-01-01Journal of Biological Chemistry

The molecular chaperone ClpX of Escherichia coli plays two distinct functions for bacteriophage Mu DNA replication by transposition. As specificity component of a chaperone-linked protease, it recognizes the Mu immunity repressor for degradation by the peptidase component ClpP, thus derepressing Mu transposition funct…

Bacterial Genetics and BiotechnologyRNA and protein synthesis mechanismsEnzyme Structure and Function

Schlieren textures in free-standing nematic films: evidence of biaxiality

S. Chandrasekhar、Geetha G. Nair、D. S. Shankar Rao 等 6 位作者1998-01-01Liquid Crystals

Conoscopic studies reveal that the nematic phase of 4,4-(p-terphenyl)-bis\[2,3,4-tri(dodecyloxy)benzal]imine is biaxial, the biaxial angle increasing with schlieren textures exhibited by the nematic phase have been between glass plates, as well as free-standing consisting entirely of s or 2-brush disclinations, confir…

Liquid Crystal Research AdvancementsPhotonic Crystals and ApplicationsSurfactants and Colloidal Systems

Structure of a Monoclinic Crystal Form of Cytochrome b1 (Bacterioferritin) from E. coli

Alain Dautant、Jean-Brice Meyer、J. Yariv 等 7 位作者1998-01-01Acta Crystallographica Section D Biological Crystallography

Crystals of E. coli cytochrome b1, alias bacterioferritin, were grown fr om a low ionic strength solution. The resulting monoclniic P21 structure was solved by molecular replacement and refined using noncrystallographi c symmetries applied to the fundamental unit, consisting of two protein subunits and a single haem.…

Protein Structure and DynamicsPhotosynthetic Processes and MechanismsEnzyme Structure and Function

Influence of the counterion on the coordinating properties of (2,2′-bipyridyl)bis(oxalato)chromate(III) anion: crystal structures and magnetic properties of AsPh4[Cr(bipy)(ox)2]·H2O and [NaCr(bipy)(ox)2(H2O)]·2H2O

M. Carmen Muñoz、Miguel Julve、Francesc Lloret 等 5 位作者1998-01-01Journal of the Chemical Society Dalton Transactions

Two new chromium(III)-containing complexes of formula AsPh4[Cr(bipy)(ox)2]·H2O 1 and [NaCr(bipy)(ox)2(H2O)]· 2H2O 2 (bipy = 2,2′-bipyridine and ox = oxalate dianion) have been synthesized and characterized by single-crystal X-ray diffraction. The structure of 1 consists of discrete [Cr(bipy)(ox)2]– mononuclear anions,…

Metal-Organic Frameworks: Synthesis and ApplicationsMetal complexes synthesis and propertiesMagnetism in coordination complexes

Nature of the Blue-Phase-III–isotropic critical point: An analogy with the liquid-gas transition

М. А. Анисимов、V. A. Agayan、Peter J. Collings1998-01-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics

The analogy with the liquid-gas critical point is analyzed to clarify the nature of the pretransitional behavior of physical properties in the vicinity of the Blue-Phase-III--isotropic transition in chiral liquid crystalline systems. The analogy is unusual: temperature serves as the ordering field and entropy plays th…

Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesMolecular spectroscopy and chirality

Catalysis by heteropoly compounds Part 39 The structure and redox behaviour of vanadium species in molybdovanadophosphoric acid catalysts during partial oxidation of isobutane

Kei Inumaru、Akiko Ono、Hiroshi Kubo 等 4 位作者1998-01-01Journal of the Chemical Society Faraday Transactions

The states and roles of vanadium of 11-molybdo-1-vanadophosphoric acid (H4PMo11VO40, PMo11V) catalyst in the partial oxidation of isobutane (2-methylpropane) were analysed by EPR, 51V and 31P NMR, IR spectroscopy, and redox titration, and compared with dodecamolybdophosphoric acid (H3PMo12O40, PMo12) catalyst. Thermal…

Polyoxometalates: Synthesis and ApplicationsCatalysis and Oxidation ReactionsChemical Synthesis and Reactions

Adsorption of albumin, collagen, and fibronectin on the surface of poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) and of poly(ε-caprolactone) (PCL) films modified by an alkaline hydrolysis and of poly(ethylene terephtalate) (PET) track-etched membranes

Laurence Rouxhet、Florence Duhoux、Olga Borecky 等 5 位作者1998-01-01Journal of Biomaterials Science Polymer Edition

The effect of alkaline hydrolysis on several surface properties of poly(hydroxybutyrate-hydroxyvalerate) (92/8) (PHB/HV) and poly(epsilon-caprolactone) (PCL) films and of poly(ethylene terephtalate) (PET) track-etched membranes have been characterized, as well as the adsorption of three proteins normally encountered b…

biodegradable polymer synthesis and propertiesElectrospun Nanofibers in Biomedical ApplicationsPolymer Surface Interaction Studies