Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVNoteFluorescence Study of the Coil−Globule Transition of a Poly(ε-caprolactone) Chain Labeled with Pyrenes at Both EndsSusana Piçarra, Pedro T. Gomes, and J. M. G. MartinhoView Author Information Centro de Química-Física Molecular, Instituto Superior Técnico, 1049-001 Lisboa, Portugal,…
NO and O 2 coadsorption on γ-Al 2 O 3 -supported Tb 4 O 7, La 2 O 3, BaO, and MgO has been investigated by in situ infrared spectroscopy coupled with temperature-programmed decomposition and desorption. BaO/γ-Al 2 O 3 and MgO/γ-Al 2 O 3 possess a higher NO x storage capability than Tb 4 O 7 /γ-Al 2 O 3 and La 2 O 3 /γ…
The interaction of three Eu(III) macrocyclic complexes Eu(THED)3+, Eu(ATHC)3+, and Eu(ATHC)3+, and Eu(S-THP)3+ with two 5'-cap model compounds, GpppG and m7GpppG is studied (THED = 1,4,7,10-tetrakis(2-hydroxyethyl)-1,4,7,-10-tetraazacyclododecane, ATHC = 1-(carbamoylmethyl)-4,7,10-tris(2-hydroxyethyl)-1,4,7,10- tetraa…
The synthesis and characterization of the trifluoromethanesulfonate salt of bis(2,6-xylyl isocyanide)tetrakis( p -tolyl)porphyrinatoiron(III), [( p -TTP)Fe(2,6-xylylNC) 2 ]CF 3 SO 3 ( 1 ), is reported. The crystal structure shows that the porphyrinate ring is strongly ruffled. The equatorial Fe−N bond distances averag…
The graft copolymerization of methyl acrylate onto sago starch was carried out by a free radical initiating process. The free radicals were produced by the chemical initiation method in which ceric ammonium nitrate was used as an initiator. It was found that the percentages of grafting, grafting efficiency, and rate o…
This research was to investigate the conversion of bagasse into a thermoformable material through esterification of the fiber matrix. For this purpose, bagasse was esterified in the absence of solvent using succinic anhydride (SA). The reaction parameters of temperature reaction, time, and amount of succinic anhydride…
Static polarizabilities and hyperpolarizabilities have been calculated for the furan homologues including furan (C 4 H 4 O), thiophene (C 4 H 4 S), selenophene (C 4 H 4 Se), and tellurophene (C 4 H 4 Te), at the Hartree−Fock and various correlation levels by ab initio molecular orbital methods. The influence of substi…
The antiferromagnetic insulating cuprate Ba$_3$Cu$_2$O$_4$Cl$_2$ contains folded CuO$_2$ chains with four magnetic copper ions ($S=1/2$) per unit cell. An underlying multiorbital Hubbard model is formulated and the superexchange theory is developed to derive an effective spin Hamiltonian for this cuprate. The resultin…
A reaction mechanism is proposed for the dissolution process of silicon dioxide networks in aqueous HF-based solutions. Etch experiments with thermally grown silicon dioxide were used to create a model for the etch process. Literature data on the etching of other vitreous silicon dioxide materials were used to refine…
A study aimed at understanding the factors that control the optical properties of DNA-linked gold nanoparticle aggregates containing oligonucleotide linkers of varying length (24−72 base pairs) is described. In this system, ∼15 nm diameter Au particles modified with (alkanethiol)-12 base oligomers are hybridized to a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThree-Dimensional Optical Data Storage Using Photochromic MaterialsSatoshi Kawata and Yoshimasa KawataView Author Information Department of Applied Physics, Osaka University, Suita, Osaka, 565-0871, Japan, and Department of Mechanical Engineering, Shizuoka University, Johoku…
The magnetization process in a square dot of permalloy having a size of 20 μm and 80 nm thickness has been investigated with a focused magneto-optical hysteresigraph. With this apparatus, it is possible to measure in a few seconds the hysteresis loop with a signal-to-noise ratio adequate for the observation of Barkhau…
Using high-resolution x-ray scattering, we have demonstrated the existence of quenched disordered charge stripes in a single crystal of $\mathrm{La}{}_{5/3}\mathrm{Sr}{}_{1/3}\mathrm{NiO}{}_{4}$ at low temperatures. Above the second-order transition critical scattering was observed due to fluctuations into the charge…
A quantitative analysis of the surface composition of the Heusler alloy NiMnSb has been undertaken using angle-resolved x-ray photoemission spectroscopy and the surface composition characterized. With sufficient annealing cycles, the stoichiometric surface evolves to a surface that is manganese rich. This indicates th…
We present a complete experimental determination of the atomic parameters necessary to unambiguously characterize two-photon ionization of atomic rubidium, i.e., the relative photoionization cross sections and the continuum wave function phase difference. We obtain these complete results through a single measurement,…
Atomic force microscopy tips are used to apply point-like local gates to manipulate the electrical properties of individual single-walled carbon nanotubes (SWNT) contacted by Ti electrodes. Depleting a semiconducting SWNT at a local point along its length leads to orders of magnitude decrease of the nanotube conductan…
Large luminescence enhancement was observed in EuS clusters formed in ultrastable zeolite-Y by solid-state diffusion in vacuum at 600 °C. The emission of EuS clusters shifts to higher energies relative to that of bulk EuS powder. The blueshift and the emission enhancement are attributed to quantum-size confinement and…
Nonlinearity is observed in Fowler–Nordheim (FN) plots of field emission from nondoped and nitrogen-doped amorphous diamond films. Based on a unified electron emission equation a detailed analysis is carried out. The results from numerical calculation of the unified equation are consistent with the experimental data.…
Field emission data from aligned high-density carbon nanotubes (CNTs) with orientations parallel, 45°, and perpendicular to the substrate have been obtained. The large-area uniformly distributed CNTs were synthesized on smooth nickel substrates via dc plasma-assisted hot filament chemical vapor deposition. CNTs with d…
The dynamic structure factors S(q-->,omega) of diamond and LiF have been measured using inelastic x-ray scattering. The experimental data are compared to results of ab initio calculations, which take into account the interaction of the excited electron with the remaining hole. In diamond, the vicinity of the indirect…