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 collapse and recrystallization of zinc-exchanged sodium zeolite-A has been observed in situ using combined X-ray spectroscopy and diffraction. The temperature at which this occurs is reduced by the presence of zinc, but the precipitation of NaAlSiO 4 (nepheline) is blocked by the nucleation of ZnAl 2 O 4 (gahnite)…
Strontium titanate sol was prepared using strontium ethyl haxanoate and titanium isopropoxide. The sol was then spin coated on fused silica, p-type single-crystal silicon wafers (100) and stainless-steel substrates and annealed to give polycrystalline, transparent, and crack-free films. The surface morphology and stru…
The structures of the liquid, glass (i.e., amorphous), rotator-phase (RP) crystal, orientational glass (OG), and the stable (monoclinic) crystal phases of ethanol are investigated by means of neutron and x-ray diffraction. The RP crystal and OG phases show an intermediate kind of disorder between that of the fully dis…
The effect of an initial coarsening step (50‐200 h at 800°C) on the subsequent densification and microstructural evolution of high–quality compacts of undoped and MgO–doped Al 2 O 3 has been investigated during fast–firing (5 min at 1750°C) and during constant–heating–rate sintering (4°C/min to 1450°C). In constant–he…
Abstract 2,3,7,8,12,13,17,18‐Octafluoro‐5,10,15,20‐tetraphenylporphyrin has been prepared from 3,4‐difluoropyrrole and benzaldehyde under Lindsey conditions. An X‐ray crystal structure study of its Zn II complex has shown that the macrocycle core is nonplanar, a result in apparent contradiction with a blue‐shifted UV/…
Two lamellar (L1, L2) and one hexagonal (H) vanadium oxide−dodecylamine mesophases have been prepared and characterized by XRD, FTIR, SEM, TEM, and NMR spectroscopy. The local environment of vanadium species was found to be controlled mainly by the synthesis temperature regardless of the nature of the mesophase. It wa…
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to rapidly detect and profile large proteins from Escherichia coli whole cell lysates in the mass range 25-500 kDa. The bacterial samples were treated with guanidine hydrochloride and Triton X-100 to disrupt and solubilize the large…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTBis(trimethylsilyl) Peroxide Extends the Range of Oxorhenium Catalysts for Olefin EpoxidationAndrei K. Yudin and K. Barry SharplessView Author Information Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute 10550 North Torr…
We have used the pulse-radiolysis time-resolved microwave conductivity technique (PR-TRMC) to study the charge transport properties of the free-radical sandwich complex bis(octakis(dodecyloxy)phthalocyaninato)lutetium(III), [(C 12 O) 8 Pc] 2 Lu. This compound displays multimesomorphic thermotropic behavior with two co…
Abstract Thiol‐stabilized CdTe nanoclusters with sizes ranging from 1.3 to 2.4 nm have been prepared in aqueous solution and separated as oxidize‐stable powders. Investigation of CdTe nanoclusters by means of X‐ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) indicates the cubic (zinc…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTUnexpected Synthetic Routes to Lanthanide Chalcogenido Clusters: Sm8Se6(SePh)12(THF)8 and [Sm7S7(SePh)6(DME)7]+Deborah Freedman, Thomas J. Emge, and J. G. BrennanView Author Information Department of Chemistry Rutgers, The State University of New Jersey Piscataway, New…
The structural dynamics of poly(propylene-glycol) of molecular weight ${M}_{W}=4000$ have been investigated over a large temperature range 10--375 K and in a wide dynamical window, corresponding to ${10}^{\ensuremath{-}3}--{10}^{14}\mathrm{Hz},$ using various light-scattering techniques. The slow dynamics were investi…
Templated silicate films with mesoporous structure on the scale of 40 Å grow at the air−water interface of concentrated surfactant solutions. X-ray reflectivity measurements show that the mechanism of this growth for our preparation involves two stages the formation of an organized surfactant layer at the interface in…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTRing-Opening Polymerization of β-Butyrolactone by Thermophilic LipasesWenhua Xie, Jun Li, Depu Chen, and Peng George WangView Author Information Department of Chemistry, University of Miami, Coral Gables, FL 33124 Cite this: Macromolecules 1997, 30, 22, 6997–6998Publication Dat…
The effect of hydrogen on strontium bismuth tantalate (SrBi2Ta2O9; SBT) ferroelectric capacitors is investigated. Using several analytical techniques such as x-ray diffraction, electron diffraction, Auger electron, scanning and transmission electron microscopies, the structural and compositional changes in the ferroel…
The treatment of the long-range dipolar interactions in simulations of mesogens is examined. After a brief reformulation of the standard Ewald summation and reaction-field methods in the general context of electrostatics using Green functions, we report the results of Monte Carlo simulations of liquid crystalline phas…
All articles of this category The Preparation of rather complex molecular assemblies can now be accomplished by using a complete set of tetrathiafulvalene (TTF) based building blocks. The facile deprotection of the 2-cyanoethyl group, a versatile protecting group for 1,3-dithiolium-2-thione-4,5-dithiolaes and TTF-thio…
Supramolecular ruthenium complexes (Ru−PyPs) with 4-pyridyl/phenyl porphyrins (PyPs) have been designed and characterized spectroscopically. Ruthenium−dimethyl sulfoxide (Me 2 SO) complexes and their carbonyl derivatives were used as precursors to synthesize adducts with Ru:PyP ratios of 1:1 and 1:2 (monomers), 2:1 (d…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTElectron Transfer between Mechanically Linked Porphyrins in a [2]RotaxaneMyriam Linke, Jean-Claude Chambron, Valérie Heitz, and Jean-Pierre SauvageView Author Information Laboratoire de Chimie Organo-Minérale URA 422 au C.N.R.S., Institut Le Bel Université Louis Pasteu…
Abstract The second‐order polarizabilities β(— 2ω; ω, ω) of six nondipolar NLO chromophores—1,3,5‐tris(isopropyl‐amino)‐2,4,6‐trinitrobenzene ( 1 ), 1,3,5‐tris(isopropylamino)‐2,4,6‐tris(trifluoro‐methylsulfonyl)benzene ( 2 ), tris(dimethyl‐imoniomethyl)methide diperchlorate ( 3 ), 2,4,6‐tris[4‐( N,N ‐diethylamino)phe…