Materials Literature
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Diprora haenaensis gen. et sp. nov. Main, an araphid filamentous diatom, is described from a cryptic, pseudoaerial habitat in Kaua'i, Hawaiian Islands. The valve ends of this new diatom have pervalvar extensions of the mantle edges, termed here prows. The frustules are heavily silicified and usually heterovalvar (one…
We show that the structure of transparent oxy-fluoride glass-ceramics formed by heat treatment of glasses of typical composition 32(SiO 2 ):9(AlO 1.5 ):31.5(CdF 2 ):18.5(PbF 2 ): 5.5(ZnF 2 ):3.5(ErF 3 ) mol% consists of ∼ 12 nm diameter, Er 3+ -doped, β-PbF 2 nano-crystals embedded in a silica-based glass network and…
We propose a simple procedure for designing an integrated single-chip grating-based thin-film filter. A simulation from a rigorous coupled-wave analysis shows that structural adjustment based on the effective medium theory can achieve the desired integration without notable performance degradation. Our spectropolarime…
Abstract Poly( dl ‐lactide) (PLA) and two of its random copolymers with glycolic acid, poly( dl ‐lactide‐ co ‐glycolide) (PLGA) with 75/25 and 50/50 component ratios of lactide/glycolide were blended with poly(ethylene oxide)/poly(propylene oxide)/poly(ethylene oxide) (PEO–PPO–PEO) triblock non‐ionic surfactants, know…
Heterogeneous platinum catalysts (Pt/SiO 2 ) obtained by the sol-gel process at pH 3 and 9 have been used in the hydrosilylation reaction of 1-alkynes using various silanes. Once the catalysts were activated they were used in the hydrosilylation of 1-alkynes after a short induction period. The product distribution was…
The oil sands industry in Alberta (Canada) has developed the composite tailings (CT) process to reduce the fluid fine tails resulting from the processing of oil sands. This process uses a chemical coagulant (gypsum or alum) to produce aggregated fines (clay), so they are retained with the coarse sand fraction of the e…
Luminescence spectra of Cr 3+ ions in nanocrystalline MgO obtained by sol-gel technology were studied. The radiative lifetime of excited 2 E states of cubic and tetragonal Cr 3+ centers was found to be considerably longer than that of bulk single crystals. This effect is caused by a modified effective refractive index…
Lyocell fibers have excellent properties, but they show a distinct tendency to fibrillate with wetting and mechanical stress. Chemical modification by esterification of these fibers could be a good means of solving this problem. A scanning electron microscopy analysis shows that treatment with polycar oxylic acids can…
The optical absorption spectra of the glasses with composition xBi2O3·(30 − x)R2O·70B2O3 (R˭Li, Na, K) and xBi2O3·(70 − x)B2O3·30Li2O (0 ≤ x ≤ 20) have been recorded in the wavelength range 350–650 nm. The glass samples were prepared by the normal melt–quench technique. The fundamental absorption edge for all the seri…
A phenomenon of bilevel solubility was observed in a TiO 2 ‐doped (2.0 wt%) alumina with bimodal microstructure sintered in N 2 . Surface contributions to dopant signals in individual grains were identified and removed, using a spatially resolved energy dispersive spectroscopy analysis. Two levels of solubility, 1.005…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTNanoblends of Incompatible Polymers by Direct Space-Confined PolymerizationShu-Hua Chan, Yi-Yang Lin, and Ching TingView Author Information Union Chemical Laboratories, Industrial Technology Research Institute, 321 Kuang-Fu Road, Se…
Measurement of cation selectivity in soils provides important information about the affinity and binding strength of a particular cation on soil surfaces. Gaines‐Thomas ( K GT ) selectivity coefficients were determined for a variety of K/Ca and K/Pb ratios on an Oxisol and Ultisol soil from Puerto Rico. The calculated…
Abstract Aramid (kevlar‐49) fibers were surface treated by two different methods to induce roughness and then used to produce unidirectional nylon 66 based composites. The transcrystallinity generated around the treated fibers was characterized by SEM and polarized light microscopy and compared with the regular transc…
Quantum-chemical open-shell method with parametrization INDO is used to construct the model of a large unit cell for the [Si- V ] 0 impurity complex in diamond. It is shown that the ground spin-triplet state of the complex exerts tunnel (rather than Jahn-Teller) splitting associated with off-center shift of Si atom al…
The chemical grafting of alkanethiol-terminated poly(ethylene glycol) to a gold substrate from dimethylformamide solution was monitored by in situ ellipsometry for several molar concentrations. In the initial stage a layer of mushroom-like moieties forms and, on a much longer time scale, is followed by conformational…
Optical functions of cobalt phthalocyanine, nickel phthalocyanine (NiPc), and iron phthalocyanine (FePc) have been determined by use of spectroscopic ellipsometry in the spectral range 1.55-4.1 eV (300-800 nm). The samples were prepared by evaporation onto glass and silicon substrates. The optical functions were deter…
Plasma enhanced chemical vapor deposition, which enables growth of carbon nanotubes directly onto substrates, is potentially suitable for preparing carbon nanotubes as electron sources in field emission displays. In this article, we report the growth of aligned carbon nanotubes by microwave plasma enhanced chemical va…
Abstract The polymerization of metal salts of N ‐chloroacetyl‐ β ‐alanine and N ‐chloroacetyl‐4‐aminobutyric acid was investigated. The former gives a mixture of polymer and a seven‐membered cyclic compound constituted of glycolic and β ‐alanine units, and its reaction proceeds in the solid state. However, liquefactio…
Abstract Due to a nanotechnology boom in science and technology, the metal nanoclusters or nanoparticles stabilized by polymers and organic ligands have achieved much attention recently all over the world. We have studied on the preparation of polymer‐stabilized metal nanoclusters by chemical methods, and applied them…
Abstract The formation of inclusion complexes of well‐known 1,4‐dihydropyridine calcium antagonists, such as nifedipine (NF) and nicardipine (NC), with β‐cyclodextrin (βCD) was investigated by differential pulse polarography (DPP) and UV‐vis spectrophotometry. The equimolar variation method indicated the formation of…