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。
Zinc supported over silica materials, which are widely used in heterogeneous catalysis, are prepared in most cases by incipient wetness impregnation with solutions of zinc nitrate. After calcination, the formation of ZnO is usually assumed, although not always fully demonstrated. The goal of this paper is to clarify t…
A volume in the new Principles and Applications in Engineering series, Tissue Engineering provides an overview of the major physiologic systems of current interest to biomedical engineers: cardiovascular, endocrine, nervous, visual, auditory, gastrointestinal, and respiratory. It contains useful definitions, tables of…
13C-NMR spectroscopy was used to estimate the p K a values for the Tyr(150) (Y150) residue in wild-type and mutant class C beta-lactamases. The tyrosine residues of the wild-type and mutant lactamases were replaced with (13)C-labelled L-tyrosine ([ phenol -4-(13)C]tyrosine) in order to observe the tyrosine residues se…
We study a two-dimensional (2D) system of macroions, trapped at the interface between air and an aqueous electrolyte solution, in the presence of a dielectric substrate approaching the air-water interface from the water side. Working within the linear Debye-Hückel theory, we investigate how the microion-averaged inter…
Using a perturbation theory with a hard-sphere reference system we have directly calculated free energies of fluid and solid phases of aluminum with an embedded atom model potential. Unlike other approaches such as thermodynamic integration, we do not require any simulations. Moreover, the free energies of the two dif…
Angle-dependent X-ray photoelectron spectroscopy (ADXPS) is used to measure end group concentration depth profiles for blends of surface active ω-fluorosilane polystyrene with nonfunctional polystyrene. The fluorine signal is in all cases enhanced at the surface, indicating surface segregation of the lower surface ten…
Doping of polyaniline with a new family of protonating agents, namely sulfosuccinates with alkyl or alkoxy substituents, is discussed. The resulting polyaniline-sulfosuccinates exhibit a lamellar type structural organization in which stacks of polymer chains are separated by dopant anions. Although structurally simila…
Computer simulations were used to study the gel transition occurring in colloidal systems with short-range attractions. A colloid-polymer mixture was modeled and the results were compared with mode coupling theory (MCT) expectations and with the results for other systems (hard-spheres system and Lennard-Jones system).…
A growing group of polyfunctional precursors of polymer networks contains more than one branch point (cross-link). The bonds they extend lead either to another branch point or to a functional group. When such precursors are cross-linked, these branch points are gradually activated to reach the status of elastically ac…
Thiol-derivatized gold clusters (i.e. nano-sized gold crystals coated with a thiolate monolayer, Aun(SR)m, with m ≪ n) based on n-alkanethiols have been obtained by treatment of gold clusters embedded in poly(N-vinylpyrrolidone) (PVP) with thiols. Dodecanethiol (DDT), hexadecanethiol (HDT), and octadecanethiol (ODT) h…
Novel two-dimensional octupoles containing azo groups and their oligomers have been synthesized and their first hyperpolarizabilities were determined. The λmax and β(0) values of azo octupoles are nearly the same regardless of the nature of the bridge or the conjugation length. On the other hand, 1,3,5-tricyano-2,4,6-…
A combination of characterization techniques has been employed to obtain a full description of the structure and chemical state of a series of Co−W/SiO 2 catalysts used for the production of single-walled carbon nanotubes (SWNT) by CO disproportionation at 750−950 °C. The state of Co and W on a series of silica-suppor…
We report the results of experiments to estimate the moisture expansion of several modern and ancient clay brick ceramics from the time of manufacture. From these data we propose a new expansion law, in which the expansive strain increases as (age)(1/4) approximately. Such time dependence is consistent with a mechanis…
Using ab initio local spin-density-functional formalism, we study the occurrence of spin polarization in quasi-one-dimensional heterostructured C/BN nanotubes. At the zigzag boundary connecting carbon and boron nitride segments of tubes, we find atomiclike states that acquire magnetization when partly filled. Whereas…
Abstract Blends of two semicrystalline polymers, poly( L ‐lactic acid) (PLLA) and poly‐ p ‐dioxanone (PPD) have been prepared by solvent casting in different compositions. Thermal, morphological, and mechanical properties of the blends were studied using modulated differential scanning calorimetry, wide‐angle X‐ray di…
Density functional theory has been used to study the effects of solvent coordination on the structure and formation of the titanium hydroperoxo species believed to be the active intermediate in oxidation reactions with Ti(IV)−H 2 O 2 catalytic systems. Titanium hydroperoxo intermediates possessing a variety of coordin…
Enzymelike kinetics were observed in the hydrolysis of 7-hydroxy-1-methylquinolium esters 2 under the catalysis of three of a family of synthetic peptide dendrimers 1. Their synthesis was based on a symmetrical branching diamino acid (B), three variable amino acid positions (A1, A2, A3=His, Asp, Ser), and a disulfide…
The calculated structures of a supported Rh6 cluster (depicted) demonstrate that protons of surface OH groups of the oxide support migrate onto the cluster. This migration results in the oxidation of metal atoms that are in close contact with the support. The energy released by this reverse hydrogen spillover is estim…
For the first time, the molecular weight distribution and extent of side reactions have been quantified in polyurethane prepolymers. A combination of NMR, size exclusion chromatography, and mass spectrometry has been used to measure the molecular weight distribution. The values obtained are consistent with Flory's ste…
Be my guest: A new family of supramolecular inclusion compounds is introduced which relies upon second-sphere hydrogen-bonding interactions to assemble highly stable layered networks (see picture). These solids have great potential for structural variation. They are possibly inorganic analogues of a well-studied host…