Materials Literature
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We have identified a strategy to communicate a chemical signal between two independent molecular components. One of them is a photoactive merocyanine that switches to a spiropyran, releasing a proton, when stimulated with visible light. The other is a 4,4'-pyridylpyridinium monocation that captures the released proton…
Four years after the first structure determination by powder diffractometry (SDPD) round robin, a second one shows that SDPD is still not routine.
We use the shear transformation zone (STZ) theory of dynamic plasticity to study the necking instability in a two-dimensional strip of amorphous solid. Our Eulerian description of large-scale deformation allows us to follow the instability far into the nonlinear regime. We find a strong rate dependence; the higher the…
Magnesium oxide nanocrystals are shown to be selective catalysts for the benzylation of aromatics with benzyl chloride, in the order xylene > toluene >> benzene. Normal polycrystalline MgO is not as effective as the nanomaterials. However, at the highest surface area, normally most reactive MgO samples (aerogel prepar…
We have characterized the structure, molecular orientation, and crystallization kinetics of isothermally crystallized thin (film thickness d < 500 nm) and ultrathin films ( d < 100 nm) of poly(ethylene oxides) on oxidized silicon substrates by a combination of microscopic and spectroscopic methods. In situ hot stage a…
The effect of Cr 3+ concentration on the various hyperfine interactions for the ferrite system Li 0.5+t Cr x Sb t Fe 2.5-2t-x O 4 , 0.0 ≤ x ≤ 1.0, x in steps of 0.2 and t = 0.1, have been studied at room temperature using Mössbauer spectroscopy. The isomershift and the quadrupole splitting are almost negligibly influe…
Abstract Electrical resistivity measurements have been performed on Cu x As 40 Se 60– x glasses with x between 0 and 28 at% of Cu. The resistivity of these glasses continuously decreases and saturates at higher quasi‐hydrostatic pressures. The pressure derivative of the electrical resistivity shows distinct changes as…
The photoionization spectra of isolated chromium clusters from ${\mathrm{Cr}}_{4}$ to ${\mathrm{Cr}}_{25}$ have been recorded. The vertical ionization energies ${(E}_{i}^{v})$ derived from the spectra decrease discontinuously with increasing cluster size. The ${E}_{i}^{v}$ values determined for ${\mathrm{Cr}}_{n}$ spe…
The Landau-de Gennes model for nematic liquid crystal bulk and interfaces has been extended to nematic triple lines involving the intersection of two isotropic fluids and one nematic liquid crystalline phase. A complete set of bulk, interface, and triple line force and torque balance equations has been formulated. The…
Direct measurements of the magnetoelastic (ME) stresses in a Cu/Ni(200nm)/Cu/Si(001) epitaxial film are reported. The ME coefficient ${B}^{\ensuremath{\gamma},2}{=B}_{1}$ has been determined as a function of the applied magnetic field $(\ifmmode\pm\else\textpm\fi{}15\mathrm{kOe})$ and the temperature (300--10 K). The…
Abstract Raman scattering in ε‐GaSe has been investigated at room temperature in a diamond anvil cell by using helium gas as a pressure transmitting medium. The first observation of the solid–solid phase transition under pressure from a hexagonal structure at ambient pressure to a NaCl‐type at around 29.2 GPa is repor…
The dielectric behavior of 95.5% Pb(Zn1/3Nb2/3)O3–4.5% PbTiO3 single crystals oriented along 〈001〉 direction with and without dc electric field has been studied at cryogenic temperatures. A pronounced low-temperature dielectric relaxation process was observed below 200 K; the relaxation rate follows the Arrhenius law…
Configural Frequency Analysis (CFA) provides an up-to-the-minute comprehensive introduction to its techniques, models, and applications. Written in a formal yet accessible style, actual empirical data examples are used to illustrate key concepts. Step-by-step program sequences are used to show readers how to employ CF…
Results of ab initio embedded-cluster calculations indicate that the doublet ground state of the $\mathrm{V}\ensuremath{-}{\mathrm{O}}_{R}\ensuremath{-}\mathrm{V}$ rung originates from a $\mathrm{V}{3d}_{\mathrm{xy}}^{1}--{\mathrm{O}}_{R}{2p}_{y}^{1}--\mathrm{V}{3d}_{\mathrm{xy}}^{1}$ configuration. In the high temper…
Selective growth of aligned carbon nanotubes (CNTs) by pyrolysis of iron (II) phthalocyanine (FePc) on quartz substrate patterned photolithographically by metallic silver has been demonstrated. Micro/nanopattern of aligned CNTs can be achieved by using a photomask with features on a microscale. With convenient use of…
The oxygen reduction reaction (ORR) at platinum electrodes covered with perfluorosulfonated ionomer film was studied in 0.05 mol dm -3 H 2 SO 4 in the presence of various kinds of ammonium ions. Ammonium ion derivatives (R 4 N) 2 SO 4 (R = H, CH 3 ) and (R 4 N)HSO 4 (R = C 2 H 5, C 3 H 7, and C 4 H 9 ) were added with…
The iron complex of hemiporphycene, a molecular hybrid of porphyrin with porphycene, was incorporated into the apomyoglobin pocket to examine ligand binding ability of the iron atom in the novel porphyrinoid. Apomyoglobin was successfully coupled with a stoichiometric amount of ferric hemiporphycene to afford the reco…
Abstract We studied the structure of single‐walled carbon nanotubes under hydrostatic pressure by first‐principles calculations. The circular tubes collapse at high pressure (7 GPa) to a phase with an elliptical cross‐section. The elliptical structure leads to the formation of diamond‐like bonds between the tubes at t…
Inclusion compounds (ICs) were obtained for the first time from a semifluorinated n -alkane (F(CF 2 ) 8 (CH 2 ) 16 H, abbreviated F 8 H 16 ) with β-cyclodextrin (β-CD) in water. Because of the hydrophobic nature of the two constituent blocks, the semifluorinated alkane readily penetrates the hydrophobic CD's cavity, t…
The atomistic origin of photoinduced vector (polarization-dependent) phenomena in As–Se films is determined by extended x-ray absorption fine structure with in situ exposure to polarized laser light. A vector structural change is observed directly for any material: there is an expansion of the nearest-neighbor distanc…