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。
Abstract In contrast to BiF 3 , the other three Bi‐halides catalyzed the ring‐opening polymerization of ε‐caprolactone (ε‐CL) in bulk. A temperature of 140 °C was found to be advantageous for rapid polymerization and optimum molecular weights. At this temperature, the reactivity of the catalysts increases in the order…
We have demonstrated that the rod segments with lateral dendritic chains self-assemble into unique stepped strips in which the rods are aligned parallel to the strip long axis. This unique organization of the rod segments arises from a balance between the energetic gain of a parallel arrangement of the rods and the re…
A novel biodegradable copolymer, poly(1,4-dioxan-2-one) (PPDO) grafted soy protein isolate (SPI) (SPI- g -PPDO), was investigated. The ring-opening graft copolymerization of SPI- g -PPDO was carried out with stannous octoate as a co-initiator/catalyst in the presence of azeotropic solvent at 80 °C. The molecular struc…
We consider a spin-1 model of strain pseudospins $S(\stackrel{P\vec}{r})=0,\ifmmode\pm\else\textpm\fi{}1$ that arise from a triple-well Landau free energy for a square/rectangle or ``austenite-martensite'' structural transformation of a two-dimensional lattice. The pseudospin model has elastic-compatibility-induced po…
The high-pressure structure and dynamics of PbZr0.40Ti0.60O3 were investigated by means of neutron diffraction, X-ray diffraction, and resonance Raman spectroscopy. The complex (P4mm, Cm, Cc, F1, F1) phase transition sequence is characterized by these techniques. On the basis of the results of structure refinements, t…
Hydrogen-terminated intrinsic diamond is a most unusual insulator since in contact with air or electrolyte it develops a hole accumulation layer just below the surface. When immersed in electrolyte the hole concentration responds to ionic charges and potentials and this response can be monitored by measuring the condu…
Prior to the implementation of multi-walled carbon nanotubes in microelectronic devices, investigating their electronic structure down to the nanometer scale is necessary. In that prospect, we used scanning tunneling microscopy (STM) to study the detailed atomic scale structure of double-walled carbon nanotubes, each…
Supercritical carbon dioxide (SC CO 2 ) was used as a carrier/solvent for the “dry” alumination of mesoporous silica to prepare aluminum-containing mesoporous MCM-41. The effect of alumination on the structure and crystallinity of the materials was studied. In addition, the hydrothermal and thermal stability of this m…
Dynamics of the nonassociated supercooled liquids N-methyl-epsilon-caprolactam (NMEC) and glycerol in the frequency domain are investigated using full complex-nonlinear-least-squares fitting of immittance spectroscopy data for appreciable temperature ranges above the glass transition. Such fitting, not previously used…
Several experiments have shown that polystyrene (PS) films with thicknesses of h ≈ 2 R G (where R G is the radius of gyration of the polymer) exhibited nonliquidlike behaviors even in the molten state. By measuring the surface spectrum of PS films subjected to different thermal annealing, we show that similar nonliqui…
Tunneling times in absorptive and dispersive media are considered, as are the relations between them. Group delay and dwell time are used as the most appropriate tunneling time characterizations. A general expression that relates these two quantities, valid for all linear media (with both positive and negative index o…
Abstract The spontaneous movement of condensate drops by application of a bulk temperature gradient on the heat transfer surface in Marangoni condensation was investigated, with consideration for applications to heat transfer devices. In the Marangoni condensation process, the removal of condensate on the heat transfe…
One of the most attractive features of diamond is its robust p -type surface conductivity that develops spontaneously under atmospheric conditions on hydrogen-terminated samples. An electrochemical charge transfer between diamond and an air-borne redox couple has been suggested to be responsible for the spontaneous ap…
We report here the selective formation of nanosized cavities on barium titanate (BaTiO 3 ) nanocubes through a simple acid etching route in hydrothermal environment. Microstructural analysis reveals that the etching process is size dependent with small cavity preferentially formed on the nanocubes greater than a chara…
We present a detailed investigation into the origin of photoluminescence (PL) from silicon quantum dots in hydrogenated amorphous silicon nitride annealed in oxygen ambient. On the basis of structural characterization, temperature-dependent PL, time-resolved PL, and PL excitation spectra, we identify that the luminesc…
Abstract The thermal oxidation at 130°C of polyoxymethylene homopolymer (H) and copolymer (C) samples of close initial molar masses has been studied by gravimetry, rheometry, X ray scattering, and tensile testing. Both samples undergo random chain scission and depolymerization. Their crystallinity ratio increases, whe…
Abstract Commercial sunflower oil was epoxidized, and epoxidized sunflower oil (ESO) was used as a thermal stabilizer for polyvinyl chloride (PVC). Semirigid and plasticized formulations stabilized with ESO were realized. Three plasticizers were used: dioctyle phthalate (DOP), diisodecycle phthalate (DIDP), and diison…
Electronic localization is numerically studied in disordered bilayer graphene with an electric-field-induced energy gap. Bilayer graphene is a zero-gap semiconductor, in which an energy gap can be opened and controlled by an external electric field perpendicular to the layer plane. We found that, in the smooth disorde…
Abstract Sm‐doped ZnWO 4 powders and films have been prepared with wet chemical methods. XRD analysis indicated that single‐phase Sm‐doped ZnWO 4 were formed above a calcining temperature of 400 °C, and the particle size and intensity of XRD peak of the powders were varied with calcining schedules. SEM micrographs ind…
This study provides kinetic and isotopic evidence for the identity and kinetic relevance of elementary steps in CH 3 OH−H 2 O reactions on monofunctional Cu-based catalysts. H 2, CO 2, and CO were the only products formed in these reactions, which proceed via kinetically relevant C−H bond activation in chemisorbed met…