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A direct implementation of the second-order derivatives of multiconfigurational SCF energies and an analysis of the preconditioning in the associated response equation

Anders Bernhardsson、Roland Lindh、Jeppe Olsen 等 4 位作者1999-02-01Molecular Physics

A direct implementation of the reduced multiplication scheme of the Rys—Gauss quadrature in the computation of the second-order geometric derivatives for MCSCF wavefunctions is presented. Characteristics unique to this implementation are simultaneous evaluation of first- and second-order two-electron integral derivati…

Advanced Chemical Physics StudiesNonlinear Optical Materials ResearchElectron Spin Resonance Studies

High‐Resistivity Grain Boundaries in CaO‐Doped MnZn Ferrites for High‐Frequency Power Application

Andrej Žnidaršić、Miha Drofenik1999-02-01Journal of the American Ceramic Society

The microstructural development and magnetic properties of MnZn ferrites doped with various amounts of CaO and sintered in atmospheres containing various oxygen concentrations were investigated. The results indicate a strong link among the amount of CaO segregated in the grain boundary, the oxygen concentration during…

Magnetic Properties and Synthesis of FerritesMagnetic Properties and ApplicationsElectromagnetic wave absorption materials

Application of the SSA calorimetric technique to characterize LLDPE grafted with diethyl maleate

L. Márquez、Iyi Rivero、Alejandro J. Müller1999-02-01Macromolecular Chemistry and Physics

A linear low density polyethylene (LLDPE) was functionalized with diethyl maleate (DEM) using different amounts of a peroxide as initiator. The modified polymers were characterised by means of FTIR and 1H NMR spectroscopy and the percentage of grafted DEM was determined. When the initiator concentration is increased f…

Polymer crystallization and propertiesMicroplastics and Plastic PollutionRecycling and Waste Management Techniques

Near-infrared study of short-range disorder of OH and F in monoclinic amphiboles

Jean-Louis Robert、Giancarlο Della Ventura、F. C. Hawthorne1999-02-01American Mineralogist

Amphiboles were synthesized along the joins tremolite-fluorotremolite, richterite-fluororichterite and potassic-richterite-potassic-fluororichterite at 750 °C and 1 kbar P(H 2 O). Infrared spectra of the amphiboles were recorded in the principal OH-stretching region. Amphiboles of the tremolite-fluorotremolite series…

Geological and Geochemical AnalysisCrystal Structures and PropertiesNuclear materials and radiation effects

Lower pressure limit of diamond growth in inductively coupled plasma

Kungen Teii、Toyonobu Yoshida1999-02-01Journal of Applied Physics

A study of diamond growth at pressures below 20 mTorr by using an inductively coupled radio frequency plasma is presented. Emissive and Langmuir probes, and optical emission spectroscopy were used to examine the plasma, and deposits were obtained on single crystalline silicon and diamond substrates with controlling th…

Metal and Thin Film MechanicsDiamond and Carbon-based Materials ResearchLaser-induced spectroscopy and plasma

Bulk Laser Damage in CsLiB6O10 Crystal and Its Dependence on Crystal Structure

Masashi Yoshimura、Tomosumi Kamimura、Kouki Murase 等 7 位作者1999-02-01Japanese Journal of Applied Physics

We investigated bulk laser damage in CsLiB 6 O 10 (CLBO) and its relation to crystal structure. The damage thresholds of CLBO, with the laser irradiation direction || <001> and polarization || <100>, were determined to be 29 GW/cm 2 at 1.064 µm, and 6.4 GW/cm 2 at 0.266 µm, using a single-shot Q -switched…

Geological and Geochemical AnalysisHigh-pressure geophysics and materialsCrystal Structures and Properties

Infrared Spectra and Elemental Composition in Recent Biogenic Calcites: Relationships between the ν 4 Band Wavelength and Sr and Mg Concentrations

Yannicke Dauphin1999-02-01Applied Spectroscopy

Biogenic calcites show various chemical contents (Sr and Mg) related to the systematic position of the organisms. It is well known that algae, octocorallia, and echinoderm tests are composed of high Mg calcites, whereas mollusc shells are composed of lower Mg calcites. DRIFT (diffuse reflectance infrared Fourier trans…

Paleontology and Stratigraphy of FossilsCalcium Carbonate Crystallization and InhibitionCephalopods and Marine Biology

Continuous Amination of Propanediols in Supercritical Ammonia

Achim Fischer、Tamás Mallát、Alfons Baiker1999-02-01Angewandte Chemie International Edition

Enhancements in selectivity by a factor of 4 to 18 were observed in the near critical regions of ammonia during the Co- and Ni-catalyzed synthesis of 1,3-diaminopropanes. These results are attributed to the higher concentration of ammonia at the surface of the catalyst, which favors the amination and suppresses degred…

Catalytic Processes in Materials ScienceIonic liquids properties and applicationsCatalysis and Oxidation Reactions

“Superductile” Semicrystalline ABC Triblock Copolymers with the Polystyrene Block (A) as the Matrix

Vittoria Balsamo、Friederike von Gyldenfeldt、Reimund Stadler1999-02-01Macromolecules

The relationship between the microphase morphology and stress−strain behavior of a polystyrene- block -polybutadiene- block -poly(ε-caprolactone) SBC triblock copolymer has been investigated with polystyrene as the major component. The semicrystalline PCL block does not change significantly the basic morphology, but i…

Polymer crystallization and propertiesPolymer Surface Interaction StudiesBlock Copolymer Self-Assembly

Calculation of the hole concentration in boron-doped diamond

F.-G. Fontaine1999-02-01Journal of Applied Physics

Calculations of the hole concentration and its activation energy in boron-doped diamond are presented. The detailed structure of the valence band is taken into account by using a temperature-dependent degeneracy factor. The calculations indicate that the customary disregard of the spin-orbit band leads to the overesti…

Semiconductor materials and devicesDiamond and Carbon-based Materials ResearchAdvancements in Semiconductor Devices and Circuit Design

Computational investigations of structural changes resulting from point mutations in a collagen-like peptide

Teri E. Klein、Conrad C. Huang1999-02-01Biopolymers

The results of 0.5-1.0 ns molecular dynamics simulations of the collagen-like peptides [(POG)4(POA)(POG)4]3 and [(POG)9]3 (POG: proline-hydroxyproline-glycine) are presented. All simulations were performed using the AMBER-94 molecular mechanical force field with a shell of TIP3P waters surrounding the peptides. The in…

Chemical Synthesis and AnalysisCollagen: Extraction and Characterization

High-pressure instrument for small- and wide-angle x-ray scattering. II. Time-resolved experiments

Miloš Steinhart、Manfred Kriechbaum、Karin Pressl 等 6 位作者1999-02-01Review of Scientific Instruments

An instrument to facilitate small- and wide-angle x-ray scattering measurements of samples under elevated hydrostatic pressures or exposed to pressure jumps is described. Pressure from atmospheric up to 0.35 GPa is produced by a motor-driven, piston-type generator and transferred through a network containing pressuriz…

Protein Structure and DynamicsForce Microscopy Techniques and ApplicationsEnzyme Structure and Function

Nanostructured Dihexadecyldimethylammonium-Poly(1,4-phenylene-ethinylene-carboxylate): An Ionic Complex with Blue Electroluminescence

Andreas F. Thünemann1999-02-01Advanced Materials

Transferral of the interesting fluorescence properties, seen in solution, of a brittle solid polymer with a conjugated backbone to a material in a more convenient state is shown to be possible. A flexible, mesomorphously structured film is obtained by complexing the brittle polymer with a surfactant, resulting in the…

Conducting polymers and applicationsMesoporous Materials and CatalysisLuminescence and Fluorescent Materials

Dynamics near free surfaces of molecular dynamics simulated Ni 0.5 Zr 0.5 metallic glass films

B. Böddeker、H. Teichler1999-02-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics

Results are reported from molecular dynamics simulations of glass forming films with ${\mathrm{Ni}}_{0.5}{\mathrm{Zr}}_{0.5}$ adapted potentials, which show a dramatic enhancement of the dynamics near the surface. After relaxation of the film for ${10}^{\ensuremath{-}8}--{10}^{\ensuremath{-}7}$ s, the dynamics is inve…

Material Dynamics and PropertiesGlass properties and applicationsMetallic Glasses and Amorphous Alloys

Low-pressure transformation of graphite to diamond under irradiation

Y. Lyutovich、Florian Banhart1999-02-01Applied Physics Letters

It is demonstrated experimentally that an irradiation-induced transformation of planar as well as curved graphite to diamond can be carried out without applying pressure. A specimen containing both graphite and diamond is irradiated at high temperature with an electron beam in an electron microscope. It is observed th…

High-pressure geophysics and materialsDiamond and Carbon-based Materials ResearchIon-surface interactions and analysis

Coarsening of the phase structure in immiscible polymer blends. Coalescence or ostwald ripening?

I. Forteln�、A. ivn�、J. J za1999-02-01Journal of Polymer Science Part B Polymer Physics

The results of theories of the Ostwald ripening and coalescence applied to molten quiescent polymer blends with dispersed phase structure were analyzed. From a comparison of predictions of the theories with available experimental results follows that coarsening of the phase structure in quiescent polymer blends with m…

Polymer crystallization and propertiesRheology and Fluid Dynamics StudiesBlock Copolymer Self-Assembly

Glass Transition Temperature Depression of Elastomers Blended with Poly(propene)s of Different Stereoregularities

Dietmar Mäder、Matthias Bruch、Ralph-Dieter Maier 等 5 位作者1999-02-01Macromolecules

Glass temperature depression, measured by means of dynamic mechanical analysis, of elastomers blended together with isotactic, syndiotactic, and atactic poly(propene), PP, was detected for the first time. Two-phase melt blends consisting of PP and elastomers such as polystyrene- block -poly(ethene- co -1-butene)- bloc…

Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesEpoxy Resin Curing Processes

Phosphorus oxynitride: a thermally stable fire retardant additive for polyamide 6 and poly(butylene terephthalate)

Sergei V. Levchik、G.F. Levchik、Alexandr I. Balabanovich 等 5 位作者1999-02-01Die Angewandte Makromolekulare Chemie

The combustion performance of polyamide 6 (PA 6) and poly(butylene terephthalate) (PBT), both fire retarded by phosphorus oxynitride (PON), was studied by oxygen index (OI) and Underwriters Laboratory UL94 tests. It was shown that either PON alone or in combination with different co-additives is efficient in PA 6 and…

Energetic Materials and CombustionFlame retardant materials and propertiesThermal and Kinetic Analysis

Extended weakly nonlinear theory of planar nematic convection

Emmanuel Plaut、W. Pesch1999-02-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics

We study theoretically convection phenomena in a laterally extended planar nematic layer driven by an ac-electric field (electroconvection in the conduction regime) or by a thermal gradient (thermoconvection). We use an order-parameter approach and demonstrate that the sequence of bifurcations found experimentally or…

Liquid Crystal Research AdvancementsTheoretical and Computational PhysicsNonlinear Dynamics and Pattern Formation

A Paramagnetic Copper(III) Complex Containing an Octahedral CuIIIS6 Coordination Polyhedron

Carsten Krebs、Thorsten Glaser、Eckhard Bill 等 6 位作者1999-02-01Angewandte Chemie International Edition

Only the second octahedral, paramagnetic copper(III) complex (S=1) has now been synthesized and characterized. Six thiolato bridging ligands in the heterotrinuclear species [LCoIIICuIIICoIIIL](ClO4)3⋅2 Me2CO (L=1,4,7-tris(4-tert-butyl-2-sulfidobenzyl)-1,4,7-triazacyclononane) stabilize this rare electron configuration…

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