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。
Regular nets are defined as those with symmetry that requires the coordination figure to be a regular polygon or polyhedron. It is shown that this definition leads to five regular 3-periodic nets. There is also one quasiregular net with a quasiregular coordination figure. The natural tiling of a net and its associated…
Organic modification with aminopropyl group of two MCM-41 materials having different pore sizes (obtained from trimethylalkylammonium surfactants with different chain sizes (16 and 12 carbon atoms)) has been carried out in order to control the delivery rate of ibuprofen from the siliceous matrix. This functionalizatio…
The optical properties of metal nanoparticles have long been of interest in physical chemistry, starting with Faraday's investigations of colloidal gold in the middle 1800s. More recently, new lithographic techniques as well as improvements to classical wet chemistry methods have made it possible to synthesize noble m…
A novel alcohol dehydrogenase enzyme has been cloned from the hyperthermophilic archaeon Aeropyrum pernix and overexpressed in Escherichia coli. This zinc-containing enzyme has been crystallized by the sitting-drop vapour-diffusion method using PEG 600 as precipitant. The crystals diffract to 1.5 A resolution and belo…
Reduced layered niobate RbNa x Ca 2 Nb 3 O 10 was synthesized via the reaction of RbCa 2 Nb 3 O 10 with sodium vapor at 500 °C. The structure has been refined from X-ray powder diffraction data, revealing that this black compound crystallizes in the space group P 4 2 / ncm with a = 5.4790(3) Å, c = 28.8264(9) Å, and Z…
Cholesterol-conjugated proteinoids and their aggregation behaviors were investigated with model proteinoid systems. Model proteinoids of molecular weights in the range of 4000 to 6000 were synthesized by anhydrous thermal condensation forming a matrix with glutamic acid and aspartic acid and of naturally occurring ami…
We have synthesised a new family of dendrimers with stilbene dendrons attached to a porphyrin core via a stilbene unit and compared their properties with a family of dendrimers with the same core and dendrons but with the dendrons attached via a phenyl unit. The oxidation and reduction half potentials of the two dendr…
Abstract Polyblends of nylon 6 and liquid crystalline polymer (LCP) (Vectra A 950) are immiscible and highly incompatible, with resultant poor interfacial adhesion, large phase domains, and poor mechanical properties. In the present work, compatibilizing strategies are put forward for blends containing nylon and LCP.…
Abstract An entirely new route for the synthesis of thermally stable ordered mesoporous silicon oxynitride (MSON) by direct nitridation with nitrogen of periodic ethane-bridged mesoporous silica material is reported.
We reconsider the possibility of periodic deformations in nematic liquid crystal samples, and present a simple method to analyze their stability near the threshold. Our method consists in finding the matrix characterizing the total energy in terms of the integration constants of the linearized solutions of the variati…
Thermoascus aurantiacus xylanase is a thermostable enzyme which hydrolyses xylan, a major hemicellulose component of the biosphere. The crystal structure of this F/10 family xylanase, which has a triosephosphate isomerase (TIM) barrel (beta/alpha)(8) fold, has been solved to small-molecule accuracy at atomic resolutio…
A new approach for the replacement of heart valves consists of obtaining an acellular matrix from animal aortic valves that performs mechanically, is nonantigenic, and is free from calcification and fibroblast proliferation. Novel biochemical treatments must be developed for this purpose. In this work, we focus on the…
Dicyanamide-bound mononuclear compounds Cp(dppe)FeN(CN)2 (3) and Cp(PPh3)2RuN(CN)2 (4) were isolated in high yields by the reactions of Cp(dppe)FeCl (1) and Cp(PPh3)2RuCl (2), respectively, with excess sodium dicyanamide. Compounds 3 and 4 are excellent precursors for the design of dicyanamide-bridged binuclear comple…
To investigate the effects of polymer chemistry and topology (linear or graft copolymer) on in vivo biocompatibility and biostability based on cage implant system, various hydrogels, composed of short hydrophilic [polyethylene oxide (PEO)] and hydrophobic block, were prepared by polycondensation reaction. Poly(tetrame…
The vibrational properties (phonons) of a one-dimensional periodic phase of atoms physisorbed in the external groove of the carbon nanotube bundle are studied. Analytical expressions for the phonon dispersion relations are derived. The derived expressions are applied to Xe, Kr, and Ar adsorbates. The specific heat per…
Giant platinum-acetylides dendrimers were precisely synthesized by a divergent method; the sixth generation dendrimer, the diameter of which is larger than 10 nm, has 189 Pt atoms per molecule, and its molecular weight is as high as 139750.
The feasibility of alignment control of low-molecular-weight guest species by controlling the orientation of mesochannels in a mesoporous silica host has been shown for the first time; spectroscopically anisotropic absorption behaviour of a cyanine dye was observed upon its incorporation into the mesochannels of a mes…
The diffusive behavior of ethane and ethylene in single-walled carbon nanotubes is investigated using classical molecular dynamics simulations and density functional theory calculations. At low molecular densities, these nonspherical molecules follow a spiral path inside nanotubes with diameters of 13-22 A, which maxi…
Abstract 2,6-Di-tert-butylphenol is selectively transformed to 3,3′,5,5′-tetra-tert-butyl-4,4′-diphenoquinone in the presence of molecular oxygen using alkali-promoted Cu–Mg–Al hydrotalcites as recyclable heterogeneous catalysts.
Seven gadolinium complexes are shown to be excellent compounds for the preparation of heavy-atom derivatives for macromolecular crystallography projects. De novo phasing has been carried out using single-wavelength anomalous diffraction (SAD) on a series of gadolinium-derivative crystals of two proteins: hen egg-white…