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。
We observed a spontaneous transition from a vertical chevron texture to a striped texture (striped ``bookshelf'' texture) in a surface-stabilized film of ferroelectric liquid crystal mixture (ZLI 4237-000, from E. Merck). The transition takes place gradually, at temperatures more than 20 \ifmmode^\circ\else\textdegree…
The copper(I) complexes [Cu(4-Xdmpz)] 3 (where X = H, Cl, Br, I and CH 3 ; dmpz = 3,5-dimethylpyrazolate) and the copper(II) complexes [Cu(4-Xdmpz) 2 ] x have been synthesized and characterized. Qualitative solubility, infrared spectroscopic, and differential scanning calorimetric studies are reported for all complexe…
A simple atomistic model with two harmonic potentials between layers of atoms describes surface relaxations equivalent to those found as kink solitary waves in ferroelastic crystals. The parameters of the model are expressed in terms of the entropy term in a Landau potential and the Ginzburg gradient energy. We discus…
Ideally oriented to complex a metal ion, the three carbonyl groups of triolide 1 are parallel and pointing in the same direction. Upon complexation with a sodium ion, the ring adjusts by arching inward, tilting the CO groups towards each other. The preparation of triolide 1 from poly(R)-3-hydroxybutanoate is surprisin…
The thermal conductivities of two-dimensional crystalline, amorphous, and quasicrystalline classical models are studied via the nonequilibrium molecular-dynamics method. The behavior of the high-temperature thermal conductivities of crystal and glasses are reproduced. The difference between the thermal conductivities…
Diamond films, deposited on silicon substrates through microwave-assisted chemical vapor deposition, have been polished with a 500-eV beam of oxygen ions through the use of a planarizing layer. The films' surface roughness, in excess of 1 microm (rms) and 6 microm (peak to valley), was reduced to 35 nm (rms) and 217 n…
Abstract A model is presented to interpret the results of XPS electron take‐off experiments obtained for natural oxide films on polycrystalline tantalum. The high‐resolution spectrum of Ta 4f shows signals from Ta, TaO and Ta 2 O 5 . The angle variations of the intensity ratios Ta 2 O 5 /Ta and TaO/Ta show that the em…
The feasibility of applying the double-layer capacitor to uninterruptible power systems and electric vehicles is addressed. The double-layer capacitor improves energy storage density by two orders of magnitude over the traditional electrolytic capacitors. Compared to batteries, the energy density of the double-layer c…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydroxo and azolate derivatives of pentafluorophenyl-nickel(II) complexes. Crystal structure of [NBu4]2[{Ni(C6F5)2(.mu.-OH)}2] and [NBu4]2[{Ni(C6F5)2}2(.mu.-OH)(.mu.-pyrazolato)]Gregorio Lopez, Gabriel Garcia, Gregorio Sanchez, Joaquin Garcia, Jose Ruiz, Juan A. Hermoso, Ang…
We have studied the martensitic transformation in a family of Cu-Al-Be crystals: We have measured the entropy change of the transition using a high-sensitivity calorimeter, and the elastic anisotropy of the high-temperature phase as a function of temperature by an ultrasonic method. Both entropy change and elastic ani…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComposition dependence of the miscibility and phase structure of amorphous/crystalline polymer blends as studied by high-resolution solid-state carbon-13 NMR spectroscopyXiaoqing Zhang, K. Takegoshi, and Kunio HikichiCite this: Macromolecules 1992, 25, 9, 2336–2340Publicatio…
Collision-induced intramolecular energy transfer between N2 triplet states has been investigated for the first time under single-collision conditions. A beam containing N2 molecules in the long-lived N2(A 3Σ+u) and N2(W 3Δu) states interacted with target particles (H2, N2, NO, and all rare gases) either in a collision…
Two experiments known as Tl and T2 are performed in the test section TERMOS of the FARO facility. Quantities of the order of 100 kg of molten pure UO2 ∼3000°C are poured into 130 kg of sodium at 400°C and 0.1 MPa contained in a 0.28-m-diam test tube over a height of 2.5 m. The tests show a melt delivery rate twice as…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHexavanadium polyoxoalkoxide anion clusters: structures of the mixed-valence species (Me3NH)[VIV5VVO7(OH)3{CH3C(CH2O)3}3] and of the reduced complex Na2[VIV6O7{CH3CH2C(CH2O)3}4]M. Ishaque Khan, Qin Chen, Jon Zubieta, and David P. GoshornCite this: Inorg. Chem. 1992, 31, 9, 1…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoordination polymers of tetracyanoethylene with metal hexafluoroacetylacetonates: formation and x-ray crystal structuresAndrew G. Bunn, Patrick J. Carroll, and Bradford B. WaylandCite this: Inorg. Chem. 1992, 31, 7, 1297–1299Publication Date (Print):April 1, 1992Publication…
The cesium and tetramethylammonium (TMA) salts of polyoxotungstate anions with covalently attached organosilyl groups of formula [(RSi)2O]SiW11O39(4-), where R = CH2CH2COCH3, (CH2)3CN, and CH==CH2 (1-R, cesium salt, unless otherwise noted) have been prepared, purified, and spectroscopically characterized. The water so…
Abstract Hydrotalcites of high aluminum content have been synthesized from aluminate liquors of varying composition and activated magnesia obtained by calcination of hydroxide or hydroxycarbonate precursors. Lattice parameter measurements and chemical analyses of 21 synthetic hydrotalcites show that the aluminum subst…
The baiB gene from Eubacterium sp. strain VPI 12708 was previously cloned, sequenced, and shown to be part of a large bile acid-inducible operon encoding polypeptides believed to be involved in bile acid 7 alpha-dehydroxylation. In the present study, the baiB gene was subcloned and expressed in Escherichia coli and sh…
Abstract Reaction of 2,5-dibromopyrimidine with a zero-valent nickel complex affords poly(pyrimidine-2,5-diyl). This new polymer is easily converted into electrical conducting materials by chemical and electrochemical reductions, the latter reduction occurring at the highest potential (−1.75 V vs. Ag/Ag+) among report…
The bipolymer calf thymus deoxyribonucleic acid (DNA) is employed to stabilize cadmium sulfide crystallites in the quantum confinement size regime (Q-CdS). In this work, the synthesis and characterization of these semiconductor 'quantum dots' is described. These Q-CdS clusters are easily prepared in aqueous solution a…