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。
Alkoxides are of great interest as precursors for sol-gel processing of advanced ceramic materials, but there is very little general knowledge about the low-valent 3d-element alkoxides. The novel oxo-alkoxide, [Mn19O12(moe)14-(moeH)10].MOEH (MOE = OC2H2-OCH3), was prepared, by metathesis and auto-decomposition, from M…
Comparison of the thermal spin crossover transition in solution of a Fe(II) dinuclear triple helicate with the analogous mononuclear complex shows that the helicate transition takes place over a wider temperature range in a two step process, implying negative cooperativity.
The synthesis of 2-[3,4-bis(n-alkan-1-yloxy)phenyl]-2-oxazolines with alkan = octan, decan, dodecan, and tridecan is presented. Their living cationic ring opening polymerization produces cylindrical macromolecules that self-organize in a hexagonal columnar two-dimensional phase. The structural analysis of these polyme…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTFormation of an Amylose−Polyester Inclusion Complex by Means of Phosphorylase-Catalyzed Enzymatic Polymerization of α-d-Glucose 1-Phosphate Monomer in the Presence of Poly(ε-caprolactone)Jun-ichi Kadokawa, Yoshiro Kaneko, Atsushi Na…
Abstract High‐refractive‐index aminoalkoxysilane‐capped pyromellitic dianhydride (PMDA)–titania hybrid optical thin films (TP0–TP8) were synthesized and characterized in this study. They were prepared with PMDA, aminopropyltrimethoxysilane, and titanium(IV) isopropoxide via a sol–gel process followed by spin coating a…
Five new bufadienolides, 3beta-formyloxyresibufogenin (1), 19-oxobufalin (2), 19-oxodesacetylcinobufagin (3), 6alpha-hydroxycinobufagin (4), and 1beta-hydroxybufalin (5), have been isolated together with the previously known bufadienolides 6-20 from the Chinese traditional drug "Ch'an Su". The structures were elucidat…
Photochromic diarylethenes that have p-phenylene-substituted benzothiophene aryl groups with and without nitronyl nitroxide radicals at both ends of the molecules were synthesized. The absorption maxima of the closed-ring isomers showed a hypsochromic shift with the increase in the pi-conjugated chain length. The uniq…
First organic radicals, now metal complexes: A successful extension to metal complexes of a well-known organic radical approach to ferromagnetism is exemplified by the triplet ground-state molecule containing two Cu(II) centers connected by a double m-phenylenediamide skeleton of the cyclophane type shown in the schem…
We present the results of theoretical investigation on the electronic structure, bonding nature and ground state properties of Th$_2$Al and Th$_2$AlH$_4$ using generalized-gradient-corrected first-principles full-potential density-functional calculations. Th$_2$AlH$_4$ has been reported to violate the "2 Årule" of H-H…
We study the current through molecular films as a function of orientation of the molecules in the film with respect to electrodes. It may change by more than an order of magnitude, depending on the angle between the axis of the molecules and the normal to the electrode. This is a consequence of a strong directional ch…
We investigate a semiclassical conductance for ballistic open three-dimensional (3-d) billiards. For partially or completely broken-ergodic 3-d billiards such as SO(2) symmetric billiards, the dependence of the conductance on the Fermi wavenumber is dramatically changed by the lead orientation. Application of a symmet…
Analysis is given of the changes of dislocation motion modes with stress and temperature variation. Different regimes of dislocation kink pair formation and spreading (motion in the random potential, in the field of random forces, the quasi-localization) are considered. Discrepancies are discussed between the theory a…
Conducting polymers expand or contract when their redox state is changed. This expansion/contraction effect can be separated in an intrinsic part because of changes of the polymer backbone on reduction/oxidation and a part depending on the surrounding electrolyte phase, because of osmotic expansion of the polymer phas…
Lightly etched single-walled carbon nanotubes are chemically reacted to form rings. The rings appear to be fully closed as opposed to open coils, as ring-opening reactions did not change the structure of the observed rings. The average diameter of the rings was 540 nanometers with a narrow size distribution. The nanot…
4-dimethylaminopyridine (DMAP) is the answer to the quest for an efficient transfer of metallic nanoparticles from organic to aqueous solutions. The picture shows the transfer of gold nanoparticles from toluene to water by the addition of DMAP (0.1 M, pH 10.5). This method enables the generation of high concentrations…
ADVERTISEMENT RETURN TO ISSUEPREVArticleDendritic Catalysts and Dendrimers in CatalysisDidier Astruc and Françoise ChardacView Author Information Laboratoire de Chimie Organique et Organométallique, UMR CNRS N°5802, Université Bordeaux I, 33405 Talence Cedex, France Cite this: Chem. Rev. 2001, 101, 9, 2991–3024Publica…
The Metropolis Monte Carlo (MMC) technique performance is compared to the performance of an iterative deconvolution method. In the MMC approach to deconvolution two Monte Carlo Procedure (MCP) are run at the same time. In one the blurred data is used as a distribution function for selection of pixels. And the second M…
Scalable rotary actuators are being developed with the help of Shape Memory Alloy (SMA) wires. Subjected to elevated temperatures SMA wires deliver large strains and high stresses. Yet their bandwidth is limited because of the time required for cooling. Bandwidth can be enhanced by miniaturizing the actuating system,…
We report our studies on the electronic structure and linear and nonlinear optical (NLO) properties of KNbO 3 using a first-principles method in the local density approximation (LDA). The calculated results for the refractive indices and second-harmonic-generation (SHG) coefficients agree well with experimental result…
Using a generalized tight-binding model, we study the changes induced in the electronic and mechanical properties of carbon nanotubes with encapsulated C 60 s. Provided enough overlap exists between the electronic states of the nanotube and those of the C 60 s, a tiny gap (~0.01-0.02 eV) opens in the band structure of…