Paul van der Schoot1997-02-08The Journal of Chemical Physics
A density functional theory is presented describing the isotropic-nematic transition in dispersions of self-assembled linear objects in two dimensions. It is shown that the transition is second order. The auto-correlation function of order parameter fluctuations is also calculated on both sides of the transition point…
Nonlinear Dynamics and Pattern FormationLiquid Crystal Research AdvancementsMaterial Dynamics and Properties
M. W. Matsen、Frank S. Bates1997-02-08OpenAlex
A detailed examination of the intermediate-segregation regime of diblock copolymer melts is presented using the incompressible Gaussian chain model and self-consistent field theory (SCFT). We find that the competition between interfacial tension and chain stretching used to describe behavior in the strong-segregation…
Advanced Polymer Synthesis and CharacterizationBlock Copolymer Self-AssemblyRheology and Fluid Dynamics Studies
Santi N. Ghosh、Sukumar Maiti1997-02-07Journal of Applied Polymer Science
Curing characteristics and the curing schedule of an epoxy-terminated polymer (ETP) were investigated using diaminodiphenyl ether (DADPE), diaminodiphenyl sulfone (DADPS), diaminodiphenyl methane (DADPM), and the hardener of a commercial epoxy, two-pack Araldite (Ciba-Geigy), as curing agents. The adhesive strength of…
Synthesis and properties of polymersEpoxy Resin Curing ProcessesFlame retardant materials and properties
Andris Ozols、Nina Nordman、Olli Salminen 等 4 位作者1997-02-06Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
The present state of the real time holographic recording in amorphous semiconductor films is reviewed including mechanisms, parameters, properties and applications. Effects of the coherent, incoherent and relaxational self- enhancement as well as the influence of the film structure relaxation are considered. Quasi-per…
Phase-change materials and chalcogenidesLiquid Crystal Research AdvancementsPhotorefractive and Nonlinear Optics
Alexei Kuzmin、J. Purāns1997-02-06Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
X-ray absorption spectroscopy (XAS) was used to study the local environment around tungsten and molybdenum ions in BaO-P<SUB>2</SUB>O<SUB>5</SUB>-WO<SUB>3</SUB> and CaO-P<SUB>2</SUB>O<SUB>5</SUB>-MoO<SUB>3</SUB> glasses having different composition of WO<SUB>3</SUB> and MoO<SUB>3</SUB> oxides. The W L<SUB>1,3</SUB> an…
Crystal Structures and PropertiesLuminescence Properties of Advanced MaterialsGlass properties and applications
Jānis Kleperis、J. Zubkans、A. Lūsis1997-02-06Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
The fundamental absorption edge of amorphous, polycrystalline and crystalline tungsten trioxide (WO<SUB>3</SUB>) thin films obtained by different techniques (thermal evaporation, rf plasma sputtering, chemical gas transport) was investigated. Special attention was paid to correct measurements of absorption values of a…
Surface Roughness and Optical MeasurementsLaser Material Processing TechniquesTransition Metal Oxide Nanomaterials
Normand Mousseau、Laurent J. Lewis1997-02-06arXiv
We present a detailed study of the effect of local chemical ordering on the structural, electronic, and dynamical properties of amorphous gallium arsenide. Using the recently-proposed ``activation-relaxation technique'' and empirical potentials, we have constructed two 216-atom tetrahedral continuous random networks w…
Materials Science
M. V. Ganduglia-Pirovano、J. Kudrnovsky、M. Scheffler1997-02-05arXiv
We calculate the difference of the ionization energies of a core-electron of a surface alloy, i.e., a B-atom in a A_(1-x) B_x overlayer on a fcc-B(001)-substrate, and a core-electron of the clean fcc-B(001) surface using density-functional-theory. We analyze the initial-state contributions and the screening effects in…
Materials Science
Jun-Hyung Cho、Matthias Scheffler1997-02-05arXiv
The significant discrepancy between first-principles calculations and experimental analyses for the relaxation of the (001) surface of rhodium has been a puzzle for some years. In this paper we present density functional theory calculations using the local-density approximation and the generalized gradient approximati…
Materials Science
L. Wendler、T. Kraft、M. Hartung 等 8 位作者1997-02-05arXiv
Grating-coupler-induced collective intersubband transitions in a quasi-two-dimensional electron system are investigated both experimentally and theoretically. Far-infrared transmission experiments are performed on samples containing a quasi-two-dimensional electron gas quantum-confined in a parabolic quantum well. For…
Materials ScienceMesoscale and Nanoscale Physics
C. Ratsch、P. Ruggerone、M. Scheffler1997-02-05arXiv
This paper gives a summary of basic concepts of density-functional theory (DFT) and its use in state-of-the-art computations of complex processes in condensed matter physics and materials science. In particular we discuss how microscopic growth parameters can be determined by DFT and how on this basis macroscopic phen…
Materials Science
Yu. Zorenko、M. M. Batenchuk、V. Gorbenco 等 4 位作者1997-02-04Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
This investigation is dedicated to studying of peculiarities of luminescent properties of the single crystalline films (SCF) of Al<SUB>2</SUB>O<SUB>3</SUB>-Y<SUB>2</SUB>O<SUB>3</SUB>-R<SUB>2</SUB>O<SUB>3</SUB> oxide system with alpha-Al<SUB>2</SUB>O<SUB>3</SUB> and garnet structure, which are used as various types of…
Radiation Detection and Scintillator TechnologiesOptical and Acousto-Optic TechnologiesLuminescence Properties of Advanced Materials
C. Stampfl、M. Scheffler1997-02-04arXiv
Recent experiments revealed an anomalous dependence of carbon monoxide oxidation at Ru(0001) on oxygen pressure and a particularly high reaction rate. Below we report density functional theory calculations of the energetics and reaction pathways of the speculated mechanism. We will show that the exceptionally high rat…
Materials Science
Zhengdong Li、Baichang Wu、Genbo Su 等 4 位作者1997-02-03Applied Physics Letters
The bulk crystals of 4-aminobenzophenone were grown from organic solution. The refractive indices and nonlinear-optical coefficients deff were measured and were reported. Blue second harmonic emission with wavelength of 433 and 460 nm was observed as pumped by a laser diode, second-harmonic generation and a conversion…
Nonlinear Optical Materials ResearchNonlinear Optical Materials StudiesPhotochemistry and Electron Transfer Studies
Michael Veith、Maria Jarczyk、Volker Hüch1997-02-03Angewandte Chemie International Edition in English
Only three of the four diethyl ether molecules are coordinated to the OH groups in the crystal structure of the aluminopolysiloxane 1. Compound 1 is obtained from tert-butoxyaluminum dihydride and diphenylsilanediol in Et2O. The fourth coordination site is sterically shielded by two oppositely placed OSi(Ph2)OSi(Ph2)O…
Synthesis and characterization of novel inorganic/organometallic compoundsChemical Synthesis and ReactionsSilicone and Siloxane Chemistry
P.M. Peters、S. N. Houde-Walter1997-02-03Applied Physics Letters
Erbium LIII-edge x-ray absorption fine structure (XAFS) and I13/24 excited state lifetime measurements were performed on aluminosilicate, fluorosilicate, and phosphate glasses with varying erbium concentration. The local erbium environment is shown to be unique in each host. In the aluminosilicate, erbium is found to…
X-ray Spectroscopy and Fluorescence AnalysisLuminescence Properties of Advanced MaterialsGlass properties and applications
Guo‐meng Zhao、M. B. Hunt、H. Keller1997-02-03Physical Review Letters
Thermal-expansion and magnetic susceptibility measurements were performed on oxygen-isotope substituted manganites $({\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{)}_{1\ensuremath{-}y}{\mathrm{Mn}}_{1\ensuremath{-}y}{\mathrm{O}}_{3}$ with a ${\mathrm{Mn}}^{4+}$ concentration of $\ensuremath{\sim}33%$. The linear t…
Rare-earth and actinide compoundsMagnetic and transport properties of perovskites and related materialsAdvanced Condensed Matter Physics
Qing Wang、Duncan W. Bruce1997-02-03Angewandte Chemie International Edition in English
The type of mesophase can be controlled by the addition of side chains to porphyrins bearing several long terminal chains (see, for instance, 1). Either columnar phases or those characteristic of rodlike molecules are formed, whose transition temperatures are lower than those found in the parent systems.
Surface Chemistry and CatalysisPhotosynthetic Processes and MechanismsPorphyrin and Phthalocyanine Chemistry
Peter Billsten、Per‐Ola Freskgård、Uno Carlsson 等 5 位作者1997-02-03FEBS Letters
Human carbonic anhydrase II pseudo-wild type (HCAIIpwt) and two truncated variants were adsorbed to approximately 9 nm silica nanoparticles. Ellipsometry was used as an indirect measure of protein adsorption. The structural changes of adsorbed proteins were investigated with the use of circular dichroism (CD), intrins…
Iron oxide chemistry and applicationsPolymer Surface Interaction StudiesEnzyme function and inhibition
Yu. I. Latyshev、O. Laborde、P. Monçeau 等 4 位作者1997-02-03Physical Review Letters
The presence of columnar defects (CDs) in NbS${\mathrm{e}}_{3}$ is shown to induce oscillations in the nonlinear charge density wave (CDW) conductivity as a function of magnetic field, when the field is oriented parallel to the axes of the defects. The period of oscillation corresponds to a change in the magnetic fiel…
Organic and Molecular Conductors ResearchPhysics of Superconductivity and MagnetismQuantum and electron transport phenomena