Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
We present a detailed calculation of the magnetic couplings between nearest-neighbor and next-nearest-neighbor coppers in the edge-sharing geometry, ubiquitous in many cuprates. In this geometry, the interaction between nearest neighbor coppers is mediated via two oxygens, and the Cu-O-Cu angle is close to 90 degrees.…
The new results are presented of the experimental study of KNbO3 and KTaO3 by means of X-ray photoelectron spectroscopy, soft X-ray emission and X-ray fluorescence spectroscopy. In particular, Nb M(4,5) spectra have been measured over a range of near-threshold excitation energies 206.5 - 240.6 eV, and Ta N(3) spectra…
The equilibrium ground-state structure of LiNbO3 in the paraelectric and ferroelectric phases is fully optimized in a first-principles calculation using the full-potential linearized augmented plane wave method. The equilibrium volume, c/a ratio and all (four, in the ferroelectric phase) internal parameters are found…
The synthesis of highly ordered macroporous materials has been accomplished in a straightforward, single-step reaction. Inorganic frameworks composed of oxides of Si, Ti, Zr, Al, W, Fe, Sb, and a Zr/Y mixture were formed from metal alkoxide precursors templated around polystyrene (latex) spheres. Monodisperse latex sp…
Photoinduced trans−cis−trans isomerization, optical storage, and surface relief gratings are demonstrated in mixed Langmuir−Blodgett (LB) films of poly[4‘-[[2-(methacryloyloxy)ethyl]ethylamino]-2-chloro-4-nitroazobenzene] (HPDR13) and cadmium stearate (CdSt). The trans−cis−trans photoisomerization of the azobenzene ch…
The structures and vibrational spectra of tetrathiafulvalene (TTF), TTF- d 4, and their radical cations have been extensively studied using the projector augmented wave method, which allows first-principles molecular dynamics based on the density functional theory. The dependence of the bond lengths and vibrational fr…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis of Passivating, Nylon-Like Coatings through Cross-Linking of Ultrathin Polyelectrolyte FilmsJeremy J. Harris, Paul M. DeRose, and Merlin L. BrueningView Author Information Department of Chemistry, Michigan State University East Lansing, Michigan 48824 Cite th…
This paper describes the stoichiometry, kinetics, and electronic resistivity of dilute graphite−sulfates intercalation compounds (stages pristine toVIII) obtained during electrochemical oxidation of graphite in 4M H 2 SO 4 solution. The stoichiometry of the reaction was determined by the use of cyclic voltammetry and…
Side-chain liquid-crystalline copolymers (SCLCPs) were synthesized from the alternating copolymerization of maleic anhydride with mesogenic 1-olefins. These SCLCPs showed high glass transition temperatures and highly ordered smectic mesophases. The mesophase width increased with spacer length. The terminal alkyl group…
The amino acid L-glutamate is a major neurotransmitter at excitatory synapses within the central nervous system. Neuronal responses to glutamate are mediated by at least three receptor types, one of which is the NMDA subtype, named for its specific ligand N-methyl-D-aspartic acid. Neurotransmitter receptors are transm…
The structures and energies of low-lying electronic states of AlN 3, Al 3 N, and Al 2 N 2 have been evaluated at the HF, MP2, QCISD(T), CCSD, and CCSD(T) levels of theory, using the several basis sets of 6-31G* (for HF), cc-pVDZ (for MP2 and QCISD(T)), and cc-pVTZ (for CCSD and CCSD(T)). The ground state of AlN 3 is p…
The spontaneous growth of thin films of carboxylic acid derivatized colloidal gold particles electrostatically immobilized at the hydrosol−organic solution interface onto moistened hydrophilic substrates is demonstrated. Immersion of the substrates up to the interface of the biphasic mixture leads to superlattice form…
The yields of tetraphenylporphyrin (TPP), N-confused tetraphenylporphyrin (NC-TPP), and tetraphenylsapphyrin (TPS) were examined under diverse conditions in the one-flask room-temperature reaction of pyrrole and benzaldehyde. The conditions examined included TFA and BF(3)-etherate catalysis, acid concentrations, pyrro…
The surface structure of alumina-supported gallium oxide catalysts for selective catalytic reduction of NO by CH 4 was studied. The XPS results showed that Ga atoms were dispersed well over the Al 2 O 3 surface for the samples with Ga 2 O 3 content below monolayer coverage (27 wt %) and that Ga 2 O 3 particles appeare…
X-ray photoelectron spectroscopy (XPS/ESCA) has been employed to investigate pure single crystals and powdered samples of yttrium aluminum garnet, Y 3 Al 5 O 12 (YAG), and YAG crystals doped with several rare earth elements (Ln = Pr, Er, Ho, Tm) and a transition metal (Cr). Core level XPS peak shapes of the main eleme…
Reactions of [M(MeCN) n ][BF 4 ] 2 salts with Bu 4 N(TCNQ) in MeOH yield M(TCNQ) 2 (MeOH) x (M = Mn, 1; Fe, 2; Co, 3; Ni, 4, x = 2−4), and reactions of MnCl 2, FeSO 4 ·7H 2 O, CoSO 4 ·7H 2 O and NiCl 2 ·6H 2 O in H 2 O produce M(TCNQ) 2 (H 2 O) 2 (M = Mn, 5; Fe, 6; Co, 7; Ni, 8 ). Infrared spectroscopy, powder X-ray d…
We study the static screening in a Hubbard-like model using quantum Monte Carlo. We find that the random phase approximation is surprisingly accurate almost up to the Mott transition. We argue that in alkali-doped Fullerenes the Coulomb pseudopotential $μ^\ast$ is not very much reduced by retardation effects. Therefor…
We discuss the problem of trapping and mobilization of nonwetting fluids during immiscible two phase displacement processes in porous media. Capillary desaturation curves give residual saturations as a function of capillary number. Interpreting capillary numbers as the ratio of viscous to capillary forces the breakpoi…
A novel approach to prepare magnetic polymeric nanoparticles by synthesis of the magnetite core and polymeric shell in a single inverse microemulsion is reported. Stable magnetic nanoparticles colloid dispersion with narrow size distribution can thus be produced. The microemulsion seed copolymerization of methacrylic…
Abstract Following an earlier paper (SPE 37274, 1997),1 we have continued to investigate the thermal stability of scale inhibitors for application in high pressure/high temperature (HP/HT) reservoirs. HP/HT reservoirs are currently under development in the North Sea and are characterised by high salinity brines (TDS &…