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。
In recent years, ion exchange membranes (IEM) have been used successfully to determine the availability of soil nutrient elements for plants. In general, the procedures proposed are applied to the determination of a single ion, and in only a few of these studies, the selectivity of these IEM was considered. Therefore,…
Abstract The residual kaolin deposits near Lastarria, South-Central Chile, were formed by weathering of subvolcanic quartz porphyry stocks, which intruded the metamorphic basement of the Coastal Cordillera. The clay fractions (<2 µm) consist mainly of poorly-ordered, very fine-grained kaolinite and lath-shaped illi…
We study fluids of hard rods in the vicinity of hard spherical and cylindrical surfaces at densities below the isotropic-nematic transition. The Onsager second virial approximation is applied, which is known to yield exact results for the bulk properties in the limit of infinitely thin rods. This approach requires the…
The intensity of a He–Ne laser (633 nm, 5 mW) transmitted by different GaSe samples is observed to change in correlation with a Nd-yttrium–aluminum–garnet laser pulse (532 nm, 7.8 ns, 3 mJ) which excites them. Such time response has been attributed to a nonlinear optical effect, i.e., a decrease in the refractive inde…
Three reactants, polyhedral oligosilsesquioxanes (POSS) (c-C6H11)7(Si7O9)(OH)3(1), butylethylmagnesium (2) and titanium tetrachloride TiCl4(3), react in three different ways according to the order of addition to form three model catalysts, A2, B2 and C2. A2, which is characterized as a bimetallic siloxane cage model c…
A new poling method utilizing the cooperativity of cyanophenyl groups was proposed in ferroelectric polycyanophenylenesulfides (PCPS). The method called “surface energy poling” takes advantage of the energy difference in the top and bottom surfaces of a polar aggregate to form a remanent polarization. The PCPS film sa…
Previously observed long-lived light-induced metastable states of transition metal nitrosyl complexes were identified as η2 nitrosyl and isonitrosyl linkage isomers. A novel technique combining low temperature X-ray crystallography and photochemistry was used to determine the geometry of the new species. Light-induced…
Silica−copper composite powders with high surface areas of about 200−400 m 2 /g have been successfully synthesized by the controlled hydrolysis/polymerization of sodium metasilicate (Na 2 SiO 3 ) and copper nitrate [Cu(NO 3 ) 2 ·3H 2 O] via partial-microemulsion and double-microemulsion processes at 28 °C. Each microe…
Silicon nitrides are synthesized by ion-assisted deposition with only one coating material and a nitrogen-ion-beam source. All the SiN(x) films are amorphous and mechanically strong. A wide range of refractive indices from 3.43 to 1.72 at a wavelength of 1550 nm is obtained. Near-IR antireflection coating and a bandpa…
The electrostatic mirror method developed by Le Gressus can be used to characterize the charge trapping properties of insulators. It is based on the measurements of the dark spot observed on a scanning electron microscope (SEM) screen working in the secondary electron mode when a beam of low energy electrons is used t…
The phase behaviour of 4-n-pentadecyloxy-3-nitrobiphenyl-4-carboxylic acid (ANBC-15) was investigated by differential scanning calorimetry, polarizing optical microscopy, and dynamic viscoelastic measurements. The phase sequence for the virgin sample of ANBC-15 is crystalsmectic C (SmC)-cubic (D)-smectic A (SmA)-'stru…
Si 3 N 4 /20‐vol%‐SiC nanocomposites with Al 2 O 3 and Y 2 O 3 as sintering additives have demonstrated very high strength at room temperature; however, the high‐temperature strength was drastically decreased, because of the low softening temperature of the grain‐boundary phase. To improve the high‐temperature strengt…
Single-wall carbon nanotubes (SWNTs) have been produced for the first time using the high-temperature pulsed arc-discharge technique, which has been developed recently in this laboratory, as reported in the conventional steady arc discharge method. Scanning electron microscopic (SEM) and transmission electron microsco…
Fine particles of chromites (MO . Cr2O3 where M = Mg, Zn, Ni, Co, and Cu) have been prepared by calcination of precursor powders prepared by evaporation of an aqueous solution of polyvinyl alcohol and stoichiometric amounts of the desired metal nitrates in appropriate mole ratios. The calcination temperatures, for the…
PURPOSE: In intravascular brachytherapy, use of high atomic number materials, such as contrast agents and metallic stents, can introduce significant dose perturbations, especially for low energy photons. The purpose of this study is to investigate dose perturbation at the interfaces of high atomic number materials and…
(1999). Thermomechanical Properties of Amorphous Saccharides: Their Role in Enhancing Pharmaceutical Product Stability. Biotechnology and Genetic Engineering Reviews: Vol. 16, No. 1, pp. 281-292.
Abstract Modeling and optimization of C 2 hydrocarbon production via the oxidative coupling of methane (OCM) were studied. The model includes both homogeneous and heterogeneous reactions. Focusing on the use of detailed reaction networks, previously validated experimentally, and the critical role of oxygen in both met…
Abstract Hydrothermal synthesis experiments were conducted to study the transition from smectite to corrensite. A mixture of oxides with the bulk composition of corrensite—Na 0.4 (Si 6.4 Al 1.6 )(Mg 7.8 Al 1.2 )-O 20 (OH) 10 —was sealed in platinum capsules with 29–37 wt. % water. One set of samples was treated in col…
Charged areas of spherulitic polypropylene (PP) samples were visualized by a simple technique of attaching oppositely charged fine dye particles. A combination of this visualization technique and thermally stimulated current (TSC) spectroscopy was applied to identify the regions where shallow and deep charge traps exi…
The spectroscopic and electrochemical properties of a series of dinuclear mixed-valence complexes containing two (triphos)Co units are reported: [(triphos)Co(L)Co(triphos)]+ (L = C6O4X2; × = H, Cl, Br, I, Me: 2a–e+; L = C14H4O4Me2: 4+). Complexes 2a–e+ are bridged by tetraoxybenzene ligands and exhibit very strong met…