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Spectroscopic Characterization of Sol−Gel-Derived Mixed Oxides

Jack M. Miller、L. Jhansi Lakshmi1998-08-01The Journal of Physical Chemistry B

Al 2 O 3 -, TiO 2 -, SiO 2 -, and ZrO 2 -based mixed-oxide supports were synthesized by sol−gel techniques using 2,4-pentanedione as the complexing/templating agent. These materials have been investigated by employing nitrogen adsorption, 27 Al, 29 Si, and 1 H solid-state magic-angle spinning nuclear magnetic resonanc…

Zeolite Catalysis and SynthesisMesoporous Materials and CatalysisAerogels and thermal insulation

Using Indole to Inhibit Copper Corrosion in Aerated 0.5 M Sulfuric Acid

Giuseppe Quartarone、Giuseppe Moretti、T. Bellomi 等 5 位作者1998-08-01CORROSION

Inhibition of copper corrosion in aerated 0.5 M sulfuric acid (H2SO4) solutions containing various concentrations of indole was studied in the temperature range from 25°C to 55°C using potentiodynamic curve, weight-loss, and analytical methods. Indole shifted corrosion potentials toward more noble values (i.e., it had…

Corrosion Behavior and Inhibition

Toughening of nylon 6 with a maleated core-shell impact modifier

Zhong‐Zhen Yu、Yuchun Ou、Zhong‐Neng Qi 等 4 位作者1998-08-01Journal of Polymer Science Part B Polymer Physics

Super-tough nylon 6 was prepared by using maleic anhydride grafted polyethylene-octene rubber/semicrystalline polyolefin blend (TPEg) as an impact modifier. The morphology, dynamic mechanical behavior, mechanical properties, and toughening mechanism were studied. Results indicate that TPEg with a semicrystalline polyo…

Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesFiber-reinforced polymer composites

Absolute radical densities in etching plasmas determined by broad-band UV absorption spectroscopy

Jean‐Paul Booth、Gilles Cunge、F. Neuilly 等 4 位作者1998-08-01Plasma Sources Science and Technology

Broad-band UV absorption spectroscopy was used to determine radical densities in reactive gas plasmas generated in a 13.56 MHz capacitively coupled parallel plate reactor. Five radical species were detected: , CF, AlF, and . Absolute (line-integrated) densities were determined in and plasmas, as were the vibrational a…

Catalytic Processes in Materials SciencePlasma Diagnostics and ApplicationsSpectroscopy and Laser Applications

Silicon-29 NMR Studies of Tetraalkylammonium Silicate Solutions. 1. Equilibria,29Si Chemical Shifts, and29Si Relaxation

Stephen D. Kinrade、Christopher T. G. Knight、David L. Pole 等 4 位作者1998-08-01Inorganic Chemistry

The addition of tetraalkylammonium cations to aqueous silicate solutions enhances the abundance of symmetric, cagelike, polysilicate anions including the cubic octamer, Si(8)O(20)(8)(-). The equilibrium ratio of tetramethylammonium (TMA) cations to the octameric silicate anion is 8:1 for solutions with a concentration…

Zeolite Catalysis and SynthesisMesoporous Materials and CatalysisChemical Synthesis and Characterization

Role of water in plasticity, stability, and action of proteins: The crystal structures of lysozyme at very low levels of hydration

H G Nagendra、N. Sukumar、M. Vijayan1998-08-01Proteins Structure Function and Bioinformatics

Earlier studies involving water-mediated transformations in lysozyme and ribonuclease A have shown that the overall movements in the protein molecule consequent to the reduction in the amount of surrounding water are similar to those that occur during enzyme action, thus highlighting the relationship among hydration,…

Protein Structure and DynamicsEnzyme Structure and FunctionHemoglobin structure and function

Enzymatic Ring-Opening Polymerization and Copolymerization of 8-Octanolide by Lipase Catalyst

Shiro Kobayashi、Hiroshi Uyama、Shuhei Namekawa 等 4 位作者1998-08-01Macromolecules

Enzymatic ring-opening polymerization and copolymerization of a nine-membered lactone, 8-octanolide (8-OL), was performed in isooctane by using various lipases of different origin as catalyst. The polymerization behavior greatly depended on the lipase origin. Candida antarctica and Pseudomonas cepacia lipases (lipases…

Enzyme Catalysis and Immobilizationbiodegradable polymer synthesis and propertiesCyclopropane Reaction Mechanisms

Relaxation dynamics in ultrathin polymer films

James A. Forrest、C. Svanberg、Károly Révész 等 6 位作者1998-08-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics

We have used photon correlation spectroscopy and quartz crystal microbalance techniques to examine the relaxation dynamics of ultrathin $(h<400\AA{})$ polystyrene films in both supported and freely standing geometries. These studies probe relaxation dynamics of polymer films in which the glass transition temperatur…

Material Dynamics and PropertiesForce Microscopy Techniques and ApplicationsMechanical and Optical Resonators

The existence regions of structural modifications in decagonal Al-Co-Ni

S. Ritsch、C. Beeli、H.‐U. Nissen 等 6 位作者1998-08-01Philosophical Magazine Letters

A subdivision of the stability region of decagonal Al-Co-Ni quasicrystals into eight different structural modifications is presented for the temperature against composition section along the maximum extension of the decagonal phase. The only methods identifying this subdivision are transmission electron microscopy tec…

Quasicrystal Structures and Properties

Parathyroid Hormone-Receptor Interactions Identified Directly by Photocross-linking and Molecular Modeling Studies

Alessandro Bisello、Amy E. Adams、Dale F. Mierke 等 7 位作者1998-08-01Journal of Biological Chemistry

Direct mapping of the interface between parathyroid hormone (PTH) and its receptor (hPTH1-Rc) was carried out by photoaffinity scanning studies. Photoreactive analogs of PTH singularly substituted with a p-benzoylphenylalanine (Bpa) at each of the first six N-terminal positions have been prepared. Among these, the ana…

Chemical Synthesis and AnalysisReceptor Mechanisms and SignalingPhotochromic and Fluorescence Chemistry

Corrosion Inhibition of Carbon Steel by Blends of Gluconate/Benzoate at Temperatures Up to 60°C

Olga Lahodny-Šarc、F. Kapor1998-08-01Materials science forum

The inhibition of carbon steel in solutions of mixtures of calcium- and zinc-gluconate with sodium benzoate was investigated in the temperature range from 25° to 60°C, under atmospheric conditions in stagnant solutions prepared with the tap water. The efficiency and the mechanism of inhibition were estimated by potent…

Corrosion Behavior and InhibitionConcrete Corrosion and DurabilitySmart Materials for Construction

Ethnopharmacological evaluation ofPergularia daemia (Forsk.) Chiov.

Satish Chandra Jain、Renuka Jain、Nicola Mascolo 等 7 位作者1998-08-01Phytotherapy Research

Pergularia daemia (Forsk.) Chiov. (Asclepiadaceae), a wild plant of the arid zone of Rajasthan, hasdemonstrated significant antiinflammatory, antipyretic and analgesic activities including the release of prostaglandin. © 1998 John Wiley & Sons, Ltd.

Essential Oils and Antimicrobial ActivityPhytochemistry and Biological ActivitiesPhytochemistry and Bioactive Compounds

Transition metal azolates from metallocenes. Part 3: Polymeric manganese(II) and nickel(II) pyrazolates; synthesis, characterization, and magnetochemistry

Alan Storr、David A. Summers、Robert C. Thompson1998-08-01Canadian Journal of Chemistry

Direct reactions of nickelocene and manganocene with molten pyrazoles in an inert atmosphere or under vacuum have led to the isolation of the following metal pyrazolate compounds: [Ni(4-Xpz) 2 ] x (where X = H, Cl and pz = pyrazolate); [M(4-Xdmpz) 2 ] x (where X = H, CH 3 , Cl, Br and M = Ni, Mn anddmpz = 3,5-dimethyl…

Magnetism in coordination complexesInorganic and Organometallic ChemistryThermal and Kinetic Analysis

Surface-enhanced Raman imaging (SERI) as a technique for imaging molecular monolayers with chemical selectivity under ambient conditions

XiaoMin Yang、Donald A. Tryk、Kazuhito Hashimoto 等 4 位作者1998-08-01Journal of Raman Spectroscopy

Surface-enhanced Raman imaging (SERI) has recently been developed as a surface imaging technique that is chemically selective, has monolayer sensitivity and can be used under ambient pressure conditions. At present, the resolution is 1–2 μm. A particularly interesting application is to image patterned self-assembled m…

Gold and Silver Nanoparticles Synthesis and ApplicationsAdvanced biosensing and bioanalysis techniquesBiosensors and Analytical Detection

Modeling of heat transfer and crystallization kinetics in thermoplastic composites manufacturing: Pultrusion

Andreas Carlsson、B. Tomas Åström1998-08-01Polymer Composites

Abstract Whereas pultrusion with thermoset resins has been widely analyzed, there is a scarcity of knowledge about pultrusion with thermoplastic resins. The aims of this work were to strive towards deeper knowledge of temperature distribution and degree of crystallinity in the composite during processing, to develop a…

Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesEpoxy Resin Curing Processes

Investigations of dislocation patterns within grains and near grain boundaries in copper by the electron channelling contrast technique in scanning electron microscopy

Z. F. Zhang、Z. G. Wang1998-08-01Philosophical Magazine Letters

In order to reveal the effect of grain boundaries (GBs) on cyclic deformation, the cyclically saturated dislocation patterns within grains and in the vicinity of GBs in a copper bicrystal with a large-angle GB and a copper multicrystal containing small-angle GBs have been observed by the electron channelling contrast…

Microstructure and mechanical propertiesMicrostructure and Mechanical Properties of SteelsCopper Interconnects and Reliability

Synthesis and Photophysical Properties of Porphyrin-Tetracyanoanthraquinodimethane-Porphyrin Triad: Photon-Dependent Molecular Switching

Hiroshi Imahori、Masato Hasegawa、Seiji Taniguchi 等 6 位作者1998-08-01Chemistry Letters

Abstract One-photon excitation of one of the two porphyrins within porphyrin-tetracyanoanthraquinodimethane-porphyrin triad with picosecond laser pulse leads to single reduction of the acceptor by intramolecular electron transfer, while an additional delayed excitation of the non-excited porphyrin results in double re…

Porphyrin and Phthalocyanine ChemistryPhotochemistry and Electron Transfer StudiesNonlinear Optical Materials Studies

On mode I fracture of shape memory alloy plates

Victor Birman1998-08-01Smart Materials and Structures

The isothermal problem of a mode I fracture of a shape memory alloy (SMA) plate is considered. Although the plate material is in the austenitic phase at a reference temperature, the martensitic transformation is triggered by high effective stresses at the tip of the crack. The phase transformation is accompanied by a…

Fatigue and fracture mechanicsStructural Behavior of Reinforced ConcreteShape Memory Alloy Transformations

Assessment of lifetime of hot‐water polyethylene pipes based on oxidation induction time data

J. Viebke、Ulf W. Gedde1998-08-01Polymer Engineering and Science

Abstract A method is presented for assessment of lifetime of polyethylene pipes undergoing thermal oxidation (Stage III failure) based on oxidation induction time ( OIT ) data obtained by DSC. The method requires pressure testing for limited time periods, sampling from unexposed and exposed pipes, the establishment of…

Asphalt Pavement Performance EvaluationCorrosion Behavior and InhibitionConcrete Corrosion and Durability

Visible Photoluminescence in Carbon-Implanted Thermal SiO2 Films

Yi Yu、Yi Yu、S.P. Wong 等 4 位作者1998-08-01physica status solidi (a)

The structures formed after the implantation of carbon in thermal SiO2 and annealing presented visible photoluminescence (PL) bands at room temperature. The peak and intensity of PL bands depended strongly on the temperature of annealing. In addition, very weak PL bands were observed after the implantation of argon in…

Carbon Nanotubes in CompositesSilicon Nanostructures and PhotoluminescenceNanowire Synthesis and Applications