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。
A simple model was developed which describes the effect of SiC submicrometer particles on the fracture toughness of alumina–SiC “nanocomposites.” This effect was attributed to the change in the fracture mode observed in alumina on adding SiC submicrometer particles, which was suggested to be a result of both matrix we…
The strength of alumina materials that had been subjected to varying degrees of densification was determined. Significant increases in strength were obtained for these materials even when there was minimal densification. For the most porous materials, the Weibull modulus values were similar but showed a significant in…
The < 2 µm fractions of Cheto (Arizona, USA) and Jelšový Potok (Slovakia) montmorillonites have been treated with 1 mol dm–3 H2SO4 for periods up to 6 h at 95 °C. The materials obtained were investigated by X-ray fluorescence (XRF), X-ray diffraction (XRD), infrared (IR) spectroscopy, and 29Si and 27Al magic-angle spi…
In the course of the mild methylation of 5,10,15,20-tetraphenyl-21-carbaporphyrin (CTPPH2) a novel isomer of N-methyl-5,10,15,20-tetraphenylporphyrin with an inverted N-methylated pyrrole ring, i.e. 2-N-methyl-5,10,15,20-tetraphenyl-21-carbaporphyrin (2-NCH3TPPH) has been synthesised. The protonation of 2-NCH3CTPPH pr…
Abstract The absorption of high kinetic energy by a small amount of material depends not only on the quality of the material but also on the structural design of the elements involved. Using a rapid response microbalance, we measured the tensions of radial threads in webs of the garden cross spider, Araneus diadematus…
This paper presents an artificial-neural-net model for predicting yarn tensile properties. A single hidden-layer neural network trained by using the back-propagation algorithm performs a functional mapping between material properties, process variables, and the resulting yarn tensile properties. The material and proce…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermodynamics of the Hydrothermal Synthesis of Calcium Titanate with Reference to Other Alkaline-Earth TitanatesMalgorzata M. Lencka and Richard E. RimanCite this: Chem. Mater. 1995, 7, 1, 18–25Publication Date (Print):January 1, 1995Publication History Published online1 Ma…
this paper we present a two dimensional dynamic simulation of the fragmentation of granular materials. We establish a two - dimensional model for a deformable, breakable, granular solid by connecting unbreakable, undeformable elements with elastic beams, similar as in Refs. 12,13 . The contacts between the particles c…
Reaction of pseudo-boehmite, [Al(O)(OH)]n, with carboxylic acids (RCO2H) results in the formation of the carboxylatoalumoxanes, [Al(O)x(OH)y(O2CR)z]n where 2x + y + z = 3 and R = C1–C13. The physical properties of the alumoxanes are highly dependent on the identity of the alkyl substituents, R, and range from insolubl…
Article Changes in Cellulose Crystallinity During Kraft Pulping. Comparison of Infrared, X-ray Diffraction and Solid State NMR Results was published on January 1, 1995 in the journal Holzforschung (volume 49, issue 6).
Tetrabenzoporphyrins (TBP) of Zn, Pd, Lu, Y, Sn and Pb have been synthesized and Pd, Sn and Lu complexes characterized by 1H NMR spectroscopy. Phosphorescence at room temperature in DMF solutions was measured for Pd and Lu complexes giving quantum yields of 7.9% and 3.5% and lifetimes of 250 µs and 870 µs, respectivel…
Introduction to thermal methods. Thermogravimetry. Differential thermal analysis and differential scanning calorimetry. Thermomechanical, dynamic mechanical and associated methods. Simultaneous techniques and product analysis. Problem solving and applications of thermal methods. Appendix: Solutions to problems in Chap…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConformational Characteristics of Ethers and Esters of p-tert-Butylcalix[5]areneDonald R. Stewart, Mariusz Krawiec, Ram P. Kashyap, William H. Watson, and C. David GutscheCite this: J. Am. Chem. Soc. 1995, 117, 2, 586–601Publication Date (Print):January 1, 1995Publication Hi…
Oxidation is the most common surface modification of polymers. This paper presents a comparison of five gas-phase surface oxidation processes: corona discharge, flame, remote air plasma, ozone, and combined UV/ozone treatments. Well-characterized biaxially oriented films of polypropylene and poly(ethylene terephthalat…
We investigated the mechanism for the inhibition of fat digestion by chitosan, and the synergistic effect of ascorbate. The important inhibition characteristics of fat digestion by chitosan from observations of the ileal contents were that it dissolved in the stomach and then changed to a gelled form, entrapping fat i…
The photoluminescence of Ce3+, Tb3+ and Sm3+, and energy transfer from Ce3+ to Tb3+, Dy3+ and Sm3+ in Mg2Y8(SiO4)6O2 are reported and discussed. The Ce3+ ion shows blue luminescence under UV excitation, and occupies simultaneously the 4f site and 6h site in the host lattice. The optimum concentrations for the 5D3 and…
The pharmaceutical utility of silk fibroin as a possible material for an oral dosage form for elderly patients was investigated. Silk fibroin gel (SFG) was prepared from its aqueous solution. The gel formation was studied as a function of adjusted pH and concentration of silk fibroin (SF). On the basis of Fourier tran…
Abstract We have used ellipsometry to measure the glass transition temperature (T g ) of ultra‐thin films of polystyrene (PS) (less than 20 nm thick) obtained by spin‐casting from solution onto silicon substrates. We find that T g in these ultra‐thin films is depressed from the bulk value in qualitative accord with ou…
Results are presented on the multisite structure of ${\mathrm{Nd}}^{3+}$ in YAG, obtained from a comparative study of melt-grown high-temperature (HT) and flux-grown (F) crystals by using optical spectroscopy in connection with x-ray data. Absorption and emission data by pumping into $^{4}$${\mathit{G}}_{5/2}$, $^{4}$…
The binding of oligopyridyl ligands to butadiyne-linked zinc porphyrin dimers, trimers and tetramers has been investigated in detail using NMR and electronic spectroscopy. Pyridine binds to zinc porphyrin monomers in CH2Cl2 solution at 300 K with binding constants of ca. 103 mol–1 dm3, while 4,4′-bipyridyl binds to th…