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。
The first example of a mesostructured tin oxide that is stable to surfactant removal has been prepared by hydrolysis of tin isopropoxide in the presence of a neutral amine surfactant (tetradecylamine).
Numerous reports have been published in the literature which describe the crystallization of macromolecules by a variety of crystallization methods, including the vapour-diffusion and microbatch techniques. This topical review compares the results of examples of proteins which were crystallized by both vapour-diffusio…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA General Synthesis of End-Functionalized Oligoanilines via Palladium-Catalyzed AminationRobert A. Singer, Joseph P. Sadighi, and Stephen L. BuchwaldView Author Information Department of Chemistry Massachusetts Institute of Technology Cambridge, Massachusetts 02139 Cit…
Zwitterionic metallocenes are a subclass of olefin polymerization catalysts which offer several potential advantages over nonzwitterionic analogues. They may be classified by the location of the counteranion within the structure of the metallocene (right). The concepts involved in the synthetic approaches taken to the…
Single-wall and multiwall carbon nanotubes are currently the subject of an intense research effort owing to the outstanding properties they may possess. Many synthesis methods have been proposed, most of which involve nanometric metal particles. In this article the various mechanisms proposed for nanotube nucleation a…
4 pages, 2 figures
The recently developed, novel superhard nanocrystalline composites nc-TiN/a-Si3N4 have been investigated by means of high resolution transmission electron microscopy. The microstructure consisting of nanocrystalline TiN imbedded within a⩽1 nm thin amorphous Si3N4, the relative amount of both phases, and the TiN-crysta…
The co-condensation of tetraethoxysilane (TEOS) and organotrialkoxysilane [(RO)3SiR′] assembled in the presence of structure-directing non-ionic polyethyleneoxide surfactant micelles provides a convenient neutral pH synthesis methodology for the one-step preparation of organically functionalized mesostructured materia…
Nonracemic helicene 1 when cooled from the melt organizes itself into macroscopic liquid crystalline fibers. Transmission electron microscopic analysis shows that the fibers are comprised of lamellae 50−200 nm wide, each only ca. 10 nm high. Analyses by X-ray and electron diffraction demonstrate that the molecules are…
The incorporation of 1.0–5.0 mol% Ce3+ or La3+ ions in MSU-X alumina molecular sieves, prepared through an N○I○ assembly pathway, dramatically improves their thermal stability without altering the mesopore size or the wormhole channel motif.
Transition metals are powerful three-dimensional templates, which can gather various functionalized ligands and orient them in a precise fashion so that complex multicomponent molecular systems can be obtained without constructing covalently-assembled edifices. The compounds thus prepared exhibit precise chemical or p…
In this paper, a new method is proposed to avoid acoustic-resonance-related instabilities in metal halide lamps when operated with a high-frequency electronic ballast. Angle modulation of the inverter switching pattern has been used as a vehicle to randomize lamp driving frequency and to limit lamp power spectrum belo…
In neutral bicarbonate-containing solutions, the predominant pathway for peroxynitrite decomposition was CO 2 -catalyzed formation of nitrate ion; that is, CO 2 was regenerated in the process. When nitrite ion was present, HCO 3 - also formed during ONO 2 - decomposition. The data could be reproduced by a kinetic mode…
The synthesis and characterisation of oligomers and polymers containing gold or platinum atoms in the backbone are reported. The polymers range in structure from the conjugated, rigid-rod type containing linear gold(I) centres to hyperbranched or dendrimeric materials containing octahedral platinum(IV) centres.
Multilayer films of molybdenum oxide were prepared by means of alternate adsorption of ammonium octamolybdate ((NH 4 ) 4 [Mo 8 O 26 ]) and poly(allylamine hydrochloride) (PAH). The films were reproducibly grown at each adsorption cycle, as monitored by a quartz crystal microbalance. Adsorption of PAH on the surface of…
Cascade molecules/dendrimers are highly branched, regularly built molecules that have now been known for two decades. While efforts in the early stage of their investigation were directed towards the development of higher generation structures and new dendritic architectures, the design of functional dendrimers is mor…
A gyroid-to-sphere shape transition has been unveiled in the growth of mesoporous silica morphologies that are synthesized under quiescent acidic aqueous conditions. It can be induced by a decrease of the acidity for a surfactant-based gyroid preparation. As the acidity is gradually lowered from the gyroid domain, the…
Addition of trace SO2 (ca. 8 ppm) to a reactant gas containing NO substantially enhanced the oxidation rate of carbon black mixed with a Pt/SiO2 catalyst, which is attributed to SO3 (or H2SO4) catalyzing the oxidation of carbon by NO2.
Chalcogenide glasses of As20S80, Ge20As20S60, As40S60 and As40S57Se3 were prepared. The wavelength dispersions of the Faraday effect for these glasses were examined. The Verdet constants of the glasses decreased at wavelengths longer than the absorption edge of the glasses. The values of the Verdet constants of the gl…
Abstract With the use of the Boltzmann superposition principle, a statistical theory of rubber elasticity, and phenomenological theory, the hysteresis loss at high strain (greater than 100%) of nonlinear viscoelastic materials has been quantified in terms of material parameters. The theory incorporates both experiment…