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。
Small-angle neutron scattering has been applied for structural investigations of amine-terminated poly(propylene imine) dendrimer (Astramol) solutions in D 2 O as a function of concentration and acidity. The forward scattering, dΣ/dΩ( Q = 0), decreases progressively by increasing dendrimer concentration due to interde…
Significant effects on catalytic activity in the epoxidation of cyclohexene with alkyl hydroperoxides are observed when the surface of mesoporous silica (MCM-41) is modified with either Ge(IV) or Sn(IV) prior to the grafting of tetracoordinated Ti(IV). Titanium centers attached via oxygen to two silicons and one germa…
The three-dimensional structures of Corynebacterium glutamicum diaminopimelate dehydrogenase as a binary complex with the substrate meso-diaminopimelate (meso-DAP) and a ternary complex with NADP+ and an isoxazoline inhibitor [Abbot, S.D., Lane-Bell, P., Kanwar, P.S.S., and Vederas, J. C. (1994) J. Am. Chem. Soc. 116,…
The electrochemistry of nine different manganese(III) dodecaphenylporphyrins containing halogen or CF 3 groups on the phenyl rings of the porphyrin macrocycle is reported. Six of the compounds were previously synthesized while three of the derivatives, (DPPF 8 )MnCl, (DPPCl 12 )MnCl and (DPPF 28 )MnCl, are reported fo…
A new reactive copolymer system with high, but still variable glass-transition temperatures was synthesized. This was accomplished by copolymerizing various N-substituted maleimides with methylvinyl or vinyl isocyanate, so that a polymer with a 1:1 composition of the two monomers is obtained. Further functionalization…
Abstract Recently there has been a large increase in the number of horizontal and highly deviated wells which are coming onto production in reservoirs with aquifers or where there is water injection. It is envisaged that many of these horizontal wells will produce both oil and brine for an extended period of time and…
We have performed first-principles static and dynamic calculations based on density functional theory and the pseudopotential method to investigate the adsorption and deprotonation of methanol on the stoichiometric (110) surface of TiO 2 . Static calculations, employing full relaxation of adsorbate and substrate atom…
The morphology and gas permeation properties of montmorillonite−polyelectrolyte self-assembled multilayer systems have been investigated. Without any special pretreatment, a stable film of montmorillonite−polymer composite was assembled on a hydrophobic poly(ethyleneterephthalate) support by means of layer-by-layer de…
We report a hybrid organic−inorganic electroactive material composed of a conducting polyaniline matrix and the phosphomolybdate anion ([PMo 12 O 40 ] 3 - ) as the active inorganic component. The material can be prepared electrochemically as thin films or chemically in the bulk, in the absence of other competing anion…
Formation of amphiphilic poly(ethylene glycol)- b -polylactide (PEG/PLA) block copolymers was accomplished by using potassium alkoxides to initiate the anionic polymerization of ethylene oxide, with the living chain end initiating the polymerization of lactide. By using potassium 3,3-diethoxypropoxide as an initiator,…
We report a systematic study of the electronic transport properties of the metallic perovskite oxide LaNiO3-delta as a function of the oxygen stoichiometry delta (delta less than or equal to 0.14). The electrical resistivity, magnetoresistance, susceptibility, Hall effect and thermopower have been studied, All of the…
An optically addressed spatial light modulator with electrolyte bisphtalocyanine of lutetium incorporated in the alignment layer is shown to be capable of memorizing a grey scale image. The relationship between the memorized grey scale and the illumination is shown. The temperature, the concentration of Lu(Pc)2 and th…
The average dimensions and the anisotropy of the main chain of a side-chain liquid crystalline polymer are determined in the different mesophases on a series of five different molecular weights. From the comparison of the main-chain dimensions, one deduces that the main chains adopt nearly a self-avoided walk in the i…
At high magnetic fields and low temperatures, numerous extreme type-II superconductors exhibit Landau quantization of electronic motion. We present an analytic construction of the quasiparticle spectrum in this regime, based on the high-field expansion. The spectrum is gapless and is separated from the familiar low-fi…
Using a simple mean-field theory and MC simulations we demonstrate the existence of a vapour-liquid transition in a fluid with purely repulsive Yukawa pair interactions and a density-dependent screening parameter. This transition does not fit into the classical Van der Waals picture, as the mechanism of liquid condens…
The lattice parameter of a single-crystal boron-doped synthetic diamond has been measured in the range 4.2-300 K by x-ray diffraction (Bond method), with precision . Over the whole range the results are consistent with A, where T is the absolute temperature. The dilation due to doping indicates a boron concentration o…
Abstract The crystal and magnetic structures of the perovskite YBaCuFeO 5+δ have been studied in the temperature range T = 4.2-300 K by powder neutron diffraction. In addition to the antiferromagnetic ordering transition at T N = 442 K, a commensurate–incommensurate magnetic transition is detected at T N ′ = 190 K. Be…
The cations [Pd2Cl2L]2+ and [KL2′+ (L = [18]aneN2S4, L′ =[15]aneO5) have been used as templates for the synthesis of unique three-dimensional polyiodide networks. The metal cations in [Pd2Cl2L]1.5I5(I3)2 are linked into infinite chains by pairwise hydrogen bonding; the resulting cationic polymers run through channels…
Not threading rings on chains, but chains through rings results in a new class of main-chain polyrotaxanes. The cations of bipyridinium salts thread through the crown ether units of a poly(ester crown ether) chain (shown below). The threading efficiency m/n of the polyrotaxane is controlled by stoichiometry and temper…
The heterogenization of a titanium(IV) silsesquioxane complex in an MCM-41 molecular sieve, by tailoring the polarity of MCM-41, results in self-assembled materials (see the space-filling model on the right) that are active, truly heterogeneous, and recyclable catalysts for liquid-phase alkene epoxidation.