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。
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…
Mg x Zn 1−x O (0<x<0.33) thin films were grown on R-plane (011̄2) sapphire substrate by metalorganic chemical vapor deposition. It was found that a thin ZnO buffer layer with a minimum thickness of ∼50 Å is needed to achieve wurtzite-type MgxZn1−xO films on R-plane sapphire. The x-ray Δω(112̄0) rocking c…
Abstract The pressure evolution of the Raman modes of Tb 3 Al 5 O 12 and Lu 3 Al 5 O 12 has been measured at room temperature and analyzed theoretically with the rigid ion model. Satisfactory agreement between experiment and theory has been found. The extracted pressure variation of the bond bending and bond stretchin…
Abstract Raman and absorption measurements under high pressure were performed in NiO single crystals at room temperature. A drastic increase of the absorption intensity was observed in the whole visible range. Furthermore, the intensity of a defect induced Raman peak located around 500 cm –1 becomes remarkably, especi…
Abstract The copolycondensations of a mixture of equal parts of isophthalic acid and terephthalic acid with tetrachlorobisphenol A (TC‐BPA) and various aromatic diol comonomers were performed with a tosyl chloride/dimethylformamide/pyridine condensing agent. The reaction with bisphenols containing nonpolar substituent…
Development of synthetic strategies that allow the formation of controlled 3-dimensional architectures composed of discrete ensembles of nanoparticles is a challenging goal. We present a synthetic strategy that allows the preparation of a macroscopic 3-D metal−semiconductor assemblage composed of 6.0-nm Au and 6.0-nm…
Different forms of solid polyaniline (Pani) and polyaniline intercalated into montmorillonite clay layers have been characterized by solid-state deuteron quadrupole echo and magic angle spinning NMR experiments. Quadrupole echo spectra reveal different fractions of fast flipping phenyl rings for conductive emeraldine…
Radical reassessment: [2.2]Paracyclophanes D and E have been identified as the main side-products of the Gilch reaction leading to poly(p-phenylene vinylene)s (PPV B). The constitution of the cyclic dimers allows the conclusion to be drawn that the PPV formation occurs by free-radical polymerization of C, initiated by…
Abstract This study explores the repassivation ability of a scratch in a chromate conversion coating (CCC) on aluminum alloy, AA2024‐T3, and hence evaluates the theory of migration of hexavalent chromium ions from the protected surface of the aluminum alloy to the exposed surface. To confirm that protection was indeed…
We report in situ electrochemical atomic force microscopic (EC-AFM) data and spectroelectrochemical results on doping−undoping of the films of regioregular poly(3-hexylthiophene) in propylene carbonate (PC) and aqueous solutions of 0.1 M LiClO 4 . The redox process of the polymer in propylene carbonate is accompanied…
Equilibrium swelling and phase behavior of liquid crystalline (LC) networks swollen in miscible nematogenic solvents has been investigated by polarizing microscopy as a function of temperature. Four systems, i.e., each of two different LC networks comprising dissimilar mesogens in two different nematic solvents, exhib…
Electronic and magnetic properties of MnN and MnAs compounds in the hypothetical cubic zinc-blende phase are studied using first-principles band structure method. We show that the high electronegativity and small atomic size of N compared to As lead to interesting consequences: MnN has a low-spin antiferromagnetic gro…
We have investigated charge carrier transport in the smectic mesophases of a liquid crystal, i.e., a 2-phenylnaphthalene derivative, by computational Monte Carlo simulation and time-of-flight experiments. The unique carrier transport properties characterized by field-independent high mobility over 10−3 cm2/V s observe…
Abstract The results of thermoelectric power ( S ) measurements of the lead chalcogenides PbS, PbSe, and PbTe at the initial NaCl‐phase, as high‐pressure semiconductors (above 2–6 GPa), and at metal phases (above 10–15 GPa) are presented. Phase transitions are discussed in terms of the model of Peierls distortion of l…
Electronic properties of single Pd atoms, deposited on Al(2)O(3)/NiAl(110), have been characterized by scanning tunneling spectroscopy at 12 K. The spectra reveal distinct conductivity resonances, assigned to discrete electronic levels in the atom. The energy position of the resonances reflects adsorption properties o…
Electrons in chains: A novel metallic chain made up of six iridium atoms (see picture) with an average oxidation state of +1.33 has been found in the complex HH,HT,HH-[Ir6(μ-OPy)6(I)2(CO)12] (Opy=2-pyridonate, H=head, T=tail). This complex provides a new link in the electronic sequence connecting dinuclear IrI and IrI…
We report on the fabrication of nanometer-scale mechanical devices incorporating multiwalled carbon nanotubes (MWNTs) as the torsional spring elements. We have employed electron beam lithography to pattern device elements directly onto individual MWNTs on a silicon dioxide substrate. The structures were suspended by e…
We report on site-selective growth of multiwalled carbon nanotubes (MWNTs) from a Co nanoparticle catalyst patterned by an ink-jet printing (IJP) technique. The dispersion of the Co nanoparticles was employed as “catalyst ink” for the IJP, and the catalyst pattern was subjected to chemical vapor deposition of acetylen…