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 quantitative evaluation of the influence of the electron transfer on the magnetic properties of mixed-valence polyoxometalates reduced by two electrons. For that purpose, we extract from valence-spectroscopy ab initio calculations on embedded fragments the value of the transfer integrals between W nearest…
New stereoregular cyclic polysilanols of the general formula [PhSi(O)OH]n (n = 6 and 12) have been selectively obtained in high yields by the reaction of cagelike oligophenylmetallasiloxanes with dilute solutions of hydrochloric acid at low temperatures. An alternative method was used to prepare cis-[PhSi(O)OH](4) fro…
The ${\mathrm{LaMn}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}{\mathrm{O}}_{3}$ series $(x=0.05,$ $0.1,$ $0.15,$ $0.3,$ $0.4,$ $0.5,$ $0.6,$ $0.8,$ $0.9)$ was studied by means of ac magnetic susceptibility, magnetization, and neutron diffraction as a function of temperature. The crystal and magnetic structures have been ref…
As this paper shows, the magnetic coupling of the inductances of two hysteresis-controlled single-phase AC-to-DC boost power converters connected in parallel leads in connection with a delayed switching of the power transistors to a self-adjusting staggered switching of the partial systems. Thereby, a significant redu…
We have studied the structural properties of CdO in the rock-salt (sodium chloride), cinnabar, orthorhombic cmcm, cesium chloride, nickel arsenide, zinc blende, and wurtzite structures using first-principles total energy calculations. Rock-salt is the calculated ground state structure with $a=4.77\mathrm{\AA{}},$ ${B}…
With the aim of better understanding the electronic and structural factors which govern electron-transfer processes in porphyrins, the electrochemistry of 29 nickel(II) porphyrins has been examined in dichloromethane containing either 0.1 M tetra-n-butylammonium perchlorate (TBAP) or tetra-n-butylammonium hexafluoroph…
${\mathrm{NdBaCo}}_{2}{\mathrm{O}}_{5.47}$ cobaltite has been investigated using neutron and synchrotron powder diffraction. At ${T}_{\mathrm{MI}}\ensuremath{\sim}360\mathrm{K},$ the compound exhibits an associated metal-insulator and spin-state transition commonly observed in these systems. At ${T}_{N}\ensuremath{\si…
Abstract Polypropylene matrix composites reinforced with single‐walled carbon nanotubes (SWNTs) were produced with different nanotube concentrations. The characterization of these new materials was performed by differential scanning calorimetry and Raman and Fourier transform infrared spectroscopy to obtain informatio…
We present a new first-principles formalism for calculating forces for optically excited electronic states using the interacting Green's function approach with the GW-Bethe Salpeter Equation method. This advance allows for efficient computation of gradients of the excited-state Born-Oppenheimer energy, allowing for th…
Single crystals of nonlinear optical material l -arginine acetate (LAA) (C 6 H 14 N 4 O 2 ·CH 3 COOH), space group P 2 1, were successfully grown for the first time by the temperature-lowering method and also by the slow evaporation method at constant temperature (30 °C) from its aqueous solution with pH at 6 and dime…
The formation of patterned nanostructure in AgCo/Pt/MgO(001) thin film is simulated by a technique of combining molecular dynamics and phase-field theory. The dislocation (strain) network existing in Pt/MgO is used as a template whose pattern is transferred to AgCo phase in spinodal decomposition, resulting in regular…
We show that the rheological properties of dry granular materials, as well as foams and emulsions, are similar to typical thixotropic fluids: under a sufficiently strong shear the viscosity decreases in time, leading to a hysteresis in an up-and-down stress ramp. This leads to a viscosity bifurcation around a critical…
A new mechanism different from the spin accumulation picture is proposed for the current induced magnetization switching in magnetic tunnel junctions by taking into account the effect of the electron electron interaction. We found in tunnel structures the possibility of an enhanced spin switching effect that, when nor…
In a recent letter, J. P. Wright et al [Phys. Rev. Lett. 87,266401 (2001) and cond-mat/0111119] have investigated the crystal structure of magnetite below the Verwey transition temperature (TV) by means of X-ray and neutron powder diffraction. We show that the interpretation given by J. P. Wright et al. is unsupported…
The structural and electronic properties of a single pentacene molecule and a pentacene molecular crystal, an organic semiconductor, are examined by a first-principles method based on the generalized gradient approximation of density functional theory. Calculations were carried out for a triclinic unit cell containing…
Hybrids of silver particles of 1 to 2 nm in size with highly branched amphiphilically modified polyethyleneimines adhere effectively to polar substrates providing environmentally friendly antimicrobial coatings.
The theoretical study of spin-crossover compounds is very challenging as those parts of the experimental findings that concern the electronic structure of these compounds can currently hardly be reproduced because of either technical limitations of highly accurate ab initio methods or because of inaccuracies of densit…
A convenient route at ambient conditions was employed to prepare narrow-dispersed ZnO nanorods in terms of size and morphology. Transmission electron microscopy and X-ray diffraction were used to characterize the structurally uniform and well-proportioned products. The as-prepared specimen exhibits strong ultraviolet…
Reducing interconnect pitch improves layout density, but degrades interconnect RC delay. Increasing metal aspect ratio (thickness/width) improves RC delay, but maximum benefits are achieved at an aspect ratio of /spl sim/2. Adding more interconnect layers improves density and performance, but practical limits are reac…
The first-principles discrete variational method, within the framework of density-functional theory, is employed to study the process of Fe grain boundary brittle cleavage and surface formation. The calculated results show that the main changes in this process take place in the fracture bonds and surface bonds. The st…