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。
Variable-temperature X-ray absorption spectroscopy measurements of sub-nanometer Pt nanoparticles on a high-surface-area gamma-alumina support reveal that the Pt-Pt bonds exhibit contraction upon heating [i.e., negative thermal expansion (NTE)]. Bare clusters under a He environment show an average linear expansion coe…
We demonstrate composite media with ferromagnetic wires that exhibit a frequency region at the microwave regime with scattering spectra strongly dependent on an external magnetic field or stress. These tunable composite materials have recently been proposed theoretically; however, no direct experimental verification h…
We have studied the chemical potential shift and changes in the electronic density of states near the Fermi level $({E}_{F})$ as a function of carrier concentration in ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ (PCMO, $0.2\ensuremath{\leqslant}x\ensuremath{\leqslant}0.65$) through t…
Abstract The adoption of biodegradable polymeric materials is increasing in food and consumer goods packaging applications, due to concerns about the disposal of petroleum‐based polymers and the increasing cost of petroleum‐based polymer resins. Currently, poly(lactide) (PLA) polymers are the biggest commercially avai…
The problem of construction of the Wannier functions (WFs) in a restricted Hilbert space of eigenstates of the one-electron Hamiltonian $\hat{H}$ (forming the so-called low-energy part of the spectrum) can be formulated in several different ways. One possibility is to use the projector-operator techniques, which pick…
Advances in first-principles computational approaches have, over the past fifteen years, made possible the investigation of physical properties of ferroelectric systems. In particular, such approaches have led to a microscopic understanding of the occurrence of ferroelectricity in perovskite oxides at ambient pressure…
We calculate the optical properties of a series of passivated non-stoichiometric CdSe clusters using two first-principles approaches: time-dependent density functional theory within the local density approximation, and by solving the Bethe-Salpeter equation for optical excitations with the GW approximation for the sel…
We combine the high dimensional model representation (HDMR) idea of Rabitz and co-workers [J. Phys. Chem. 110, 2474 (2006)] with neural network (NN) fits to obtain an effective means of building multidimensional potentials. We verify that it is possible to determine an accurate many-dimensional potential by doing low…
We have measured the temperature-dependent thermal conductivity kappa(T) of individual multiwall boron nitride nanotubes using a microfabricated test fixture that allows direct transmission electron microscopy characterization of the tube being measured. kappa(T) is exceptionally sensitive to isotopic substitution, wi…
Luminescent semiconductor nanocrystals or quantum dots (QDs) are a recentlydeveloped class of nanomaterial whose unique photophysical properties are helping tocreate a new generation of robust fluorescent biosensors. QD properties of interest forbiosensing include high quantum yields, broad absorption spectra coupled…
We have developed a probe of the electromagnetic mechanism of surface-enhanced Raman scattering via Au nanodisk arrays generated by using on-wire lithography. In this approach, disk thickness and interparticle gap are precisely controlled from 5 nm to many micrometers. Confocal Raman microscopy demonstrates that disk…
In the presence of an iridium pincer complex, dehydrogenation of ammonia borane (H3NBH3) occurs rapidly at room temperature in tetrahydrofuran to generate 1.0 equivalent of H2 and [NH2BH2]5. A metal borohydride complex has been isolated as a dormant form of the catalyst which can be reactivated by reaction with H2.
Abstract UV–vis and 1H NMR spectra provide unambiguous evidences for the disproportionation reactions of [ReVO(tpen)]3+ to give [ReIVO(tpen)]2+ and [ReVII(O)3(tpenH-κ3N,N″,N′″)]2+ (tpen = N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine) in 2:1 ratio with the important participation of water molecules.
Abstract A series of polystyrene‐ b ‐polybutadiene (PSt‐ b ‐PBd) block copolymers with various chain lengths and compositions were synthesized by sequential living anionic polymerization and then converted into the corresponding polystyrene‐ b ‐poly(ethylene‐ co ‐butene) (PSt‐ b ‐PEB) block copolymers through the sele…
Abstract Modified waterborne poly(methacrylic acid) (MPBMA) with hydrophilic and hydrophobic groups is prepared by reacting maleic anhydride/polyglycol, α‐olefine benzenesulfone, and methyl methacrylate. Using MPBMA as a ceramic dispersant, the effects of the MPBMA concentration on the rheological behavior of a cerami…
A new type of anthracene containing diamine monomer bis (4-amino 3,5 dimethyl phenyl) anthra methane was prepared by adopting a new procedure starting from 9-anthraldehyde and 2,6-dimethyl aniline. The diamine was reacted with a number of aromatic dianhydrides to form polyimides via a two step polycondensation method…
Abstract The release of commonly used dithiocarbamate accelerators, namely, zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC), zinc dibenzyldithiocarbamate, zinc isobutyldithiocarbamate, and zinc diisononyldithiocarbamate, into artificial sweat from natural rubber latex vulcanizates was studied. T…
A new diamine monomer with bis-trifluoromethyl-substituted phenyl in the side chain, α,α-bis (4-amino-3,5-dimethylphenyl)-3′,5′-bis(trifluoromethyl)phenyl methane (6FMA) was successfully synthesized. A series of fluorinated polyimides (PI-IIa-d) were prepared by reacting the diamine with various aromatic dianhydrides.…
Abstract Crystallization of glassy‐crystalline‐glassy poly(vinylcyclohexane)‐ b ‐polyethylene‐ b ‐poly(vinylcyclo hexane) (PVCH‐PE‐PVCH) triblock copolymer treated in supercritical Carbon Dioxide (scCO 2 ) was investigated by using differential scanning calorimetry (DSC) and atomic force microscope (AFM). It was found…
Pretilt angle effect on the dark-state light leakage and viewing angle of in-plane switching (IPS) liquid crystal display is investigated. As the liquid crystal (LC) pretilt angle increases, the light leakage becomes more severe and the off-axis light leakage from the out-of-plane LC directors cannot be neglected. Int…