Abhik Ghosh1997-04-01The Journal of Physical Chemistry B
Local density functional (LDF) and ab initio Hartree-Fock (HF) calculations are reported for free base porphyrin, chlorin, bacteriochlorin, and isobacteriochlorin. The LDF optimized geometries provide a detailed picture of the structural effects of peripheral hydrogenation on the C α −C β and C β −C β bond distances,…
Photosynthetic Processes and MechanismsPorphyrin and Phthalocyanine ChemistryPorphyrin Metabolism and Disorders
Herng‐Jeng Jou、Mark T. Lusk1997-04-01Physical review. B, Condensed matter
The nucleation and growth of recrystallized grains or pearlite colonies can be viewed as a structural phase transition and modeled with a set of phase-field equations. Such a micromechanical formulation is consistent with the viewpoint taken in deriving the Johnson-Mehl-Avrami-Kologoromov (JMAK) equation and delivers…
Metallic Glasses and Amorphous AlloysAluminum Alloy Microstructure PropertiesSolidification and crystal growth phenomena
M. Winterer1997-04-01Journal de Physique IV (Proceedings)
A new program is presented for the data analysis of XAFS. Comprehensive methods are available for the analysis of disordered systems.
Machine Learning in Materials ScienceInorganic Chemistry and MaterialsX-ray Diffraction in Crystallography
Arne Kienast、Lutz Galich、Keith S. Murray 等 7 位作者1997-04-01Journal of Porphyrins and Phthalocyanines
μ-Carbido diporphyrinates and diphthalocyaninates of general formula [{ Mp 2− } 2 (μ- C )] ( p 2− = tpp ( M = Fe ), oep ( Fe ), pc ( Fe , Ru ); H 2 tpp : 21H,23H-5,10,15,20-tetraphenylporphine; H 2 oep : 21H,23H-2,3,4,8,12,13,17,18-octaethylporphine; H 2 pc : 29H,31H-phthalocyanine) of formally Fe IV and Ru IV are pre…
Magnetism in coordination complexesPorphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation Mechanisms
Abdelhamid Bensalem、Bert M. Weckhuysen、Robert A. Schoonheydt1997-04-01The Journal of Physical Chemistry B
In situ diffuse reflectance spectra of supported chromium oxide catalysts are investigated for the first time at elevated temperatures under controlled reaction conditions using a specially designed diffuse reflection attachment. The obtained results are compared and discussed with those obtained by the classical diff…
Catalytic Processes in Materials ScienceCatalysis and Oxidation ReactionsPigment Synthesis and Properties
Philippe Blanchard、Hugues Brisset、Bertrand Illien 等 5 位作者1997-04-01The Journal of Organic Chemistry
Bridged dithienylethylenes (DTEs) bearing solubilizing alkyl chains at various positions (2-5) have been synthesized by McMurry dimerization of cyclopenta[b]thiophen-6-ones. In order to introduce alkyl substituents at different positions of the DTE molecule, the precursor ketones have been prepared by different strate…
Organic Electronics and PhotovoltaicsConducting polymers and applicationsPhotochromic and Fluorescence Chemistry
Johannes Kellendonk1997-04-01Journal of Mathematical Physics
We introduce a notion of equivalence on tilings which is formulated in terms of their local structure. We compare it with the known concept of locally deriving one tiling from another and show that two tilings of finite type are topologically equivalent whenever their associated groupoids are isomorphic.
Geometric and Algebraic TopologyMathematical Dynamics and FractalsQuasicrystal Structures and Properties
D. A. Zubenko、M. A. Noginov、В. А. Смирнов 等 4 位作者1997-04-01Physical review. B, Condensed matter
An analytic solution for the kinetics of nonlinear (upconversion) luminescence quenching in solid-state laser materials and other luminophosphors is obtained under the assumptions of hopping character of migration-assisted energy transfer and finite excitation lifetime. It is shown how the observables of the luminesce…
Luminescence Properties of Advanced MaterialsPhotorefractive and Nonlinear OpticsSolid State Laser Technologies
T. C. Lubensky1997-04-01Solid State Communications
Soft condensed matter physics is the study of materials, such as fluids, liquid crystals, polymers, colloids and emulsions, that are “soft” to the touch. This article will review some properties, such as the dominance of entropy, that are unique to soft materials and some properties such as the interplay between broke…
Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesAdvanced Thermodynamics and Statistical Mechanics
Thierry Braisaz、P. Rutérana、G. Nouet 等 4 位作者1997-04-01Philosophical magazine. A/Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties
Dislocations in {1012} twin boundaries in Zn were investigated using high-resolution electron microscopy. The topological parameters (Burgers vectors and step heights) of several defects have been identified and found to be in excellent agreement with theoretical predictions. The core structures of all defects studied…
Microstructure and mechanical propertiesMagnesium Alloys: Properties and ApplicationsAluminum Alloy Microstructure Properties
Hua Chang、Pei Jane Huang1997-04-01Analytical Chemistry
The advantage of Raman spectroscopy is that it can be used to identify structure. In this work, Raman spectra of CaC 2 O 4 ·H 2 O, a calibration standard for thermogravimetric analysis/differential thermal analysis (TGA/DTA), were taken or monitored continuously in a thermal process from 25 to 750 °C with a heating ra…
Layered Double Hydroxides Synthesis and ApplicationsThermal and Kinetic AnalysisChemical Synthesis and Characterization
Silvia Licoccia、Elisabetta Morgante、Roberto Paolesse 等 7 位作者1997-04-01Inorganic Chemistry
(2,3,7,8,12,13,17,18-Octamethylcorrolato)manganese(III), [Mn(OMC)], has been characterized by several physical measurements. In the presence of nitrogenous bases the complex exists as a valence tautomer [Mn(II)(OMC(*+))] as demonstrated by (1)H NMR and EPR. Complete resonance assignment in the NMR spectrum has been ac…
Magnetism in coordination complexesPorphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation Mechanisms
R. Somashekar、H. Somashekarappa1997-04-01Journal of Applied Crystallography
Line-profile simulation and matching on the basis of a paracrystalline one-dimensional Hosemann model provides a promising approach to the analysis of line broadening. Results of analysis using X-ray wide-angle data of polymers and metallic samples are compared with Warren–Averbach multiple-order and single-order meth…
Cultural Heritage Materials AnalysisX-ray Spectroscopy and Fluorescence AnalysisX-ray Diffraction in Crystallography
Jens Antony、Michael Grodzicki、Alfred X. Trautwein1997-04-01The Journal of Physical Chemistry A
A systematic study of the electronic structure of models for the active sites of heme enzymes such as peroxidases and cytochromes P450 has been carried out for high-valent transition states of their catalytic cycles, namely, compound I and compound II for peroxidases, as a function of the second axial ligand. The inve…
Magnetism in coordination complexesPorphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation Mechanisms
A. V. Sannikov、E. N. Savitskaya1997-04-01Radiation Protection Dosimetry
Calculations of the ambient dose equivalent conversion factors for neutron energies from 20 MeV to 5 GeV have been performed using the Monte Carlo high energy transport code HADRON. The kerma approximation extended to the high energy region was applied in the calculations. The results obtained are compared with the pr…
Nuclear reactor physics and engineeringRadiation Therapy and DosimetryGraphite, nuclear technology, radiation studies
Zouheir Sekkat、Jonathan Wood、Wolfgang Knoll 等 6 位作者1997-04-01Journal of the Optical Society of America B
We report on light-induced nonpolar orientation of sidechain nonlinear-optical polyimides [glass transition temperatures (Tg) up to 350 °C] containing no flexible connectors or tethers. The nonlinear-optical azo-dye chromophore is incorporated through the donor substituent as a part of the polymer backbone. This impre…
Liquid Crystal Research AdvancementsNonlinear Optical Materials ResearchNonlinear Optical Materials Studies
Olivier Lambert、Philippe Dumas、Guy Hurtrez 等 4 位作者1997-04-01Macromolecular Rapid Communications
Abstract The synthesis of an amphiphilic triarm star copolymer based on polystyrene, poly(ethylene oxide) and poly(ε‐caprolactone) block has been achieved by a novel strategy which consists in the preparation of a diblock copolymer, polystyrene‐ block ‐poly(ethylene oxide), having a protected anionic initiator group a…
Advanced Polymer Synthesis and Characterizationbiodegradable polymer synthesis and propertiesBiopolymer Synthesis and Applications
R. Kellner、Boris Mizaikoff、Michael Jakusch 等 5 位作者1997-04-01Applied Spectroscopy
In order to further improve the sensitivity of chemical IR sensors, research into a significant change in the signal generation mechanism was carried out. This effort was realized by generating the surface-enhanced IR absorption and Raman-scattering effect at silver- and gold-island-covered Ge- and ZnSe ATR surfaces f…
Gold and Silver Nanoparticles Synthesis and ApplicationsAdvanced biosensing and bioanalysis techniquesBiosensors and Analytical Detection
Elodie Bayet、F. Huet、M. Keddam 等 5 位作者1997-04-01Journal of The Electrochemical Society
A novel method of measuring local electrochemical impedance using a single vibrating probe electrode has been developed by modification of a commercial device of scanning vibrating electrode technique (SVET). The small size of the vibrating probe used by the SVET minimizes the screening effect of the probe on the dist…
Corrosion Behavior and InhibitionHydrogen embrittlement and corrosion behaviors in metalsConcrete Corrosion and Durability
Taku Iiyama、Keiko Nishikawa、Toshio Suzuki 等 7 位作者1997-04-01The Journal of Physical Chemistry B
The X-ray diffraction of CCl 4 molecules adsorbed in slit-shaped graphitic micropores was measured at 303 K. The effect of the pore width in the range of 0.75−1.13 nm on the structure of CCl 4 molecular assembly in the micropores was examined. The electron radial distribution function (ERDF) analysis was applied to th…
Phase Equilibria and ThermodynamicsSurface Chemistry and CatalysisX-ray Diffraction in Crystallography