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。
Resistivity of metals is commonly observed either to 'escalate' beyond the Ioffe-Regel limit (mean free path l equal to lattice constant a) or to 'saturate' at this point. It is argued that neither behavior is well-understood, and that 'escalation' is not necessarily more mysterious than 'saturation.'
A study on uranium and oxygen point defects in uranium dioxide using the ab initio plane-wave pseudopotential method in the local density approximation of the density functional theoretical framework is presented. Norm conserving pseudopotentials are used to describe oxygen and uranium atoms. The uranium pseudopotenti…
The fabrication of more and more miniaturized electronic and photonic devices relies on new, ingenious methods for the fabrication of spatially controlled nanostructures. Examples are electronic devices based on semiconducting nanowires and photonic devices based on chains of metallic nanoclusters that guide light by…
We have investigated the electronic properties of a C_60 molecule in between carbon nanotube leads. This problem has been tackled within a quantum chemical treatment utilizing a density functional theory-based LCAO approach combined with the Landauer formalism. Owing to low-dimensionality, electron transport is very s…
CONTRIBUTORS. PART I INTRODUCTION TO NANOMATERIALS. 1 Introduction to Nanoscale Materials in Chemistry, Edition II ( Ryan M. Richards ). 2 Unique Bonding in Nanomaterials and Powders ( Keith P. McKenna ). 3 Particles as Molecules ( C. M. Sorensen ). PART II NEW SYNTHETIC METHODS TO NANOMATERIALS. 4 Microwave Preparati…
Seventy-nine samples of polymer film thermal control (PFTC) materials have been provided by the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) for exposure to the low Earth orbit environment on the exterior of the International Space Station (ISS) as part of the Materials Internationa…
Optical overlay measurement methods are very effective since they are rapid and non-destructive. Imaging techniques need sophisticated image processing and suffer from the wave- optical resolution drawback. Presently, leading edge devices are offered with 5 though 10 nm measuring accuracy. In this paper a method is pr…
Forty-one different polymers are being exposed to the low Earth orbit (LEO) environment on the exterior of the International Space Station (ISS) for one year as part of MISSE (Materials International Space Station Experiment). MISSE is a materials flight experiment sponsored by the Air Force Research Lab/Materials Lab…
In a scanning electron microscope (SEM) top-down secondary electron image, areas within a few tens of nanometers of the line edges are characteristically brighter than the rest of the image. In general, the shape of the secondary electron signal within such edge regions depends upon the energy and spatial distribution…
Tetrahedral complexes with an excited state consisting of two closely lying triplet states are considered. The full interaction Hamiltonian, including ligand field, Jahn-Teller, pseudo-Jahn-Teller, and spin-orbit interactions is constructed. The emission-band shape is numerically calculated within the semiclassical ap…
Abstract The composition effect on morphology of polypropylene/ethylene–propylene–diene terpolymer/polyethylene (PP/EPDM/PE) and polypropylene/ethylene–propylene–diene terpolymer/polystyrene (PP/EPDM/PS) ternary blends has been investigated. In all of the blends, polypropylene as the major phase was blended with two m…
By means of molecular dynamics simulation, the crystallization process of the copolymer (ethylene-co-propene) with different branch distributions is studied at the molecular level. It is shown that subglobules formed at the branch sites along the copolymer chains and subsequently coalesced into a single globule and th…
The T2g4→4A2g luminescence of a 4.1% Cr3+ doped Cs2NaScCl6 crystal is studied as a function of hydrostatic pressure at room temperature and 15 K. The vibrational fine structure observed in the low-temperature variable pressure emission spectra is analyzed with a two configurational coordinate approach, involving the t…
${\mathrm{Sr}}_{0.85}{\mathrm{Bi}}_{2.1}{\mathrm{Ta}}_{2}{\mathrm{O}}_{9}$ is shown, by Rietveld refinement of powder neutron-diffraction data, to undergo two phase transitions at elevated temperature. The low-temperature ferroelectric phase (space group ${A2}_{1}am)$ transforms to a paraelectric phase (Amam) at ${T}_…
The electronic structure of the newly discovered superconducting perovskite ${\mathrm{MgCNi}}_{3}$ is calculated using the LMTO method. The states near the Fermi energy are found to be dominated by $\mathrm{Ni}\ensuremath{-}d.$ The Stoner factor is low while the electron-phonon coupling constant is estimated to be abo…
Abstract Postpolymerization of dimethylaminoethylmethacrylate‐methyl chloride (DMAEM‐MC) electropolymerization, with Sn +2 /EDTA as initiator, was studied. The factors that affect the stable average molecular weight of the polymer (MW ∞ ) created by postpolymerization were investigated. The results indicate that the m…
Abstract A new class of dimethyl formamide (DMF)– and acetone‐soluble conducting pyrrole–ketonic resin copolymers has been developed. This was accomplished by oxidatively polymerizing pyrrole monomer by Ce(IV) salt in the presence of methyl ethyl ketone formaldehyde resin (MEKF–R). The resulting copolymers were readil…
Abstract Stress‐relaxation experiments on four varieties of Indian silk fiber show that stress relaxation is significantly greater in non‐Mulberry silks than in the Mulberry silk and that the differences among non‐Mulberry silk fibers are relatively small. All the fibers studied also exhibit inverse stress relaxation.…
The low-temperature homogeneous broadening of the electronic transitions of ${\mathrm{Eu}}^{3+}$ and ${\mathrm{Pr}}^{3+}$ rare-earth impurity ions in ${\mathrm{Y}}_{2}{\mathrm{O}}_{3}$ and ${\mathrm{LaF}}_{3}$ nanocrystals embedded into amorphous materials (polymer and oxyfluoride glass ceramics) was studied with hole…
The vacuum systems of all scanning electron microscopes (SEMs), even in the so-called clean instruments, have certain hydrocarbon residues that the vacuum pumps do not effectively remove. The cleanliness of the vacuum and the amount and nature of these residual molecules depends on the type of the pumps and also on th…