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。
The structural transformations occurring in fibers of syndiotactic polypropylene (sPP) during stretching have been studied by wide-angle X-ray diffraction measurements, using syncrotron radiation. sPP samples were cyclically stretched and relaxed at controlled rate, while recording X-ray fiber diffraction patterns and…
Fragmentation of the SF6 molecule upon F 1s excitation has been studied by resonant photoemission. The F atomiclike Auger line exhibits the characteristic Doppler profile that depends on the direction of the photoelectron momentum relative to the polarization vector of the radiation as well as on the photon energy. Th…
Highly ordered, several nanometers thick films of alkylated large planar, polycyclic aromatic hydrocarbon (PAH) molecules have been grown on semi-metallic molybdenum disulfide substrates. The films are characterized by a two-dimensional lateral arrangement of columns standing at the surface on a macroscopic scale. The…
Sequential structure-factor data have been collected during the transformation from relaxed high-density to low-density amorphous ice at temperatures above 105 K. Trends in the measured structure factor and in particular the height of the first sharp diffraction peak as a function of its position show that, at ambient…
At room temperature, polycrystalline Fe 3 O 4 films with thicknesses in the range 5–1120 nm have been prepared by reactive sputtering. Transmission electron microscopy imaging shows that uniform Fe 3 O 4 grains are well separated by grain boundaries and their size decreases with film thickness. The change of resistivi…
Abstract The influence of different processing methods on the nature of the dispersion achieved in the creation of a polyurethane nanocomposite is presented. The nanocomposites were produced using two different types of organically modified montmorillonite clays and a sample of fine particles of silicon nitride as a r…
Temperature-dependent 1 H NMR and dilute solution viscometry coupled with dynamic light scattering techniques were used to elucidate the aqueous phase conformation of several poly(vinyl alcohol)s (PVAs) differing in their molecular architecture (i.e., degree of blockiness, molecular weight, and degree of hydrolysis).…
We developed a CVD system employing inductively coupled micronplasma generated by applying UHF (UHF microplasma). This system can be operated easily in air at atmospheric pressure with a few tens of watts of UHF power and enables us to deposit material on a wide variety of substrates. Deposition of carbon from CH 4 /A…
PMMA/Pd nanocomposites were prepared by means of free radical polymerization of methyl methacrylate using AIBN initiator in the presence of palladium acetate at 50 °C (48 h), and subsequent thermal conversion of palladium acetate into palladium metal at 120 °C (1 h). Morphological, thermomechanical, and thermal proper…
A polyelectrolyte architecture was fabricated that was composed of chitosan and organophosphorus hydrolase polycations along with thioglycolic acid-capped CdSe quantum dots (QDs) as the polyanion. This film was imaged by epifluorescence microscopy. UV−vis and emission spectroscopies were used to monitor the growth of…
Abstract The first part of this investigation focused on the synthesis and characterization of a new type of intumescent flame‐retardant (IFR) agent. Four steps were used in the synthesis process. The structure was characterized by FTIR, magic‐angle spinning nuclear magnetic resonance (MAS‐NMR) 13 C spectroscopy, and…
PURPOSE: The purpose of this study was to compare contrast enhanced MR angiography (MRA) with gadopentetate dimeglumine (Gd-DTPA) to MRA with gadobenate dimeglumine (Gd-BOPTA), a high relaxivity paramagnetic contrast agent. MATERIALS AND METHODS: Twelve patients referred for carotid artery stenosis were examined with…
Abstract In this research, a flame‐retardant water‐dispersed polyurethane resin was synthesized through incorporating phosphonate groups into the polyurethane structure in the chain‐extension step. A phosphorus‐containing reactive flame‐retardant compound was synthesized for this purpose. First, bis(4‐nitrophenyl)phen…
In contrast to the conventional photoorientation process with blue light, an orientation of 4-cyano-4‘-alkoxyazobenzene side groups parallel to the electric field vector of the incident light is generated upon irradiating films of a liquid-crystalline side-chain polymer with linearly polarized red light. The polyester…
The chemisorption of atomic hydrogen on the single-walled armchair and zigzag carbon nanotubes is studied with ab initio calculations. The binding energy of H adsorption at the exterior of the nanotubes is much greater than that at the interior. We predict that two rows of H atoms chemisorbed on selective sites exteri…
Abstract Fly ash, a waste productof thermal power stations generated in huge quantities, has been posing problems of its disposal. As such it contains a variety of inorganic oxides and is available in finely powdered form. Attempts have been made for its use as a filler in elastomers and plastics. It is important to n…
Carrier-doping effects on the structural phase transitions in ${\mathrm{SrTiO}}_{3}$ are investigated by the first-principles calculations. It is found that the instabilities of the cubic phase to both the ${\mathrm{TiO}}_{6}$-octahedron rotated phase and the ferroelectric phase are modulated characteristically by the…
The novel conjugated polymer ( 12 ) which has [2.2]paracyclophane and ferrocene units in the polymer backbone was synthesized by palladium-catalyzed polycondensation of the monomer ( 10 ) with diiodoferrocene ( 11 ). The obtained polymer ( 12 ) was soluble in common organic solvents, and the structure of 12 was confir…
The room temperature photoluminescence property of ZnO particles embedded in sol–gel silica was investigated. Three ZnO emissions at about 3.25 eV (ultraviolet (UV)), 2.8 eV (blue), and 2.45 eV (green) were observed. The blue and green emissions were ascribed to interstitial zinc and oxygen vacancy defects in ZnO. At…
High-pressure micro-discharges are promising sources of light, ions, and radicals and offer some advantages in materials processing applications as compared to other more conventional discharges. We review here results from etching experiments using stencil masks where the discharge is formed only in the pattern cutou…