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。
We present the structure of LinB, a 33-kDa haloalkane dehalogenase from Sphingomonas paucimobilis UT26, at 0.95 A resolution. The data have allowed us to directly observe the anisotropic motions of the catalytic residues. In particular, the side-chain of the catalytic nucleophile, Asp108, displays a high degree of dis…
We demonstrate a bulk process for the synthesis of Y-junction carbon nanotubes using Ti-doped Fe catalysts. It is shown that the nanotube branching can be induced or stopped at will by tuning the Ti composition in the catalyst particle that seeds the growth of nanotubes. Detailed electron microscopic studies suggest t…
NIR−FT-Raman spectra of 1,10-phenanthroline were recorded of crystalline material and three different solutions (CD 3 OD, CHCl 3, and CS 2 ) in the wavenumber range 100−1800 cm -1 . FT-IR spectra of the solid material were obtained for the range 400−1800 cm -1 . A complete assignment of the experimental vibrational sp…
The distance dependence of the local EM field associated with 84 ± 5 nm silver particles is characterized by monitoring spectral shifts in the plasmon resonance due to changes in local dielectric environment, which was controlled by coating the particles with silica layers of various thicknesses. The local EM field th…
Use of a dialkoxysilane-containing, condensable alanine amphiphile with a cleavable hexadecyl ester tail (1) as a "lizard" template for sol-gel synthesis results in the formation of a mesoporous silicate (2) whose channels are filled with an organic group of the template. Treatment of 2 with aqueous HCl allows selecti…
The effect of solvent conditions on the growth of polyelectrolyte (PE) multilayer films comprising poly(allylamine hydrochloride) (PAH) and poly(styrenesulfonate sodium salt) (PSS) on planar substrates was investigated by means of surface plasmon resonance spectroscopy (SPRS), quartz crystal microbalance (QCM), and at…
We demonstrate that the skeleton of the Fermi surface S_{F;s} pertaining to a uniform metallic ground state (corresponding to fermions with spin index s) is determined by the Hartree-Fock contribution to the dynamic self-energy. The Fermi surface S_{F;s} consists of all points which in addition to satisfying the quasi…
Crack propagation is studied numerically using a continuum phase-field approach to mode III brittle fracture. The results shed light on the physics that controls the speed of accelerating cracks and the characteristic branching instability at a fraction of the wave speed.
Solid solutions of KTaO$_{3}$ and KNbO$_{3}$ (KTN) exhibit unusual dielectric properties at ferroelectric phase transitions, which are usually associated with a Nb instability that is often explained by the large Nb dynamical charge in oxides. Using non-self-consistent VASP computations, we showed earlier that the Nb…
We have first successfully transferred the 129Xe polarization of natural isotopic composition to the proton of solid-state 1HCl via Spin Polarization-Induced Nuclear Overhauser Effect (SPINOE), by mixing the hyperpolarized 129Xe gas and the 1HCl gas and then cooling them to their condensated state in a flow system. Th…
Multiscale modeling of material properties has emerged as one of the grand challenges in material science and engineering. We provide a comprehensive, though not exhaustive, overview of the current status of multiscale simulations of materials. We categorize the different approaches in the spatial regime into sequenti…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTModels of the Bis-Histidine-Ligated Electron-Transferring Cytochromes. Comparative Geometric and Electronic Structure of Low-Spin Ferro- and FerrihemesF. Ann WalkerView Author Information Department of Chemistry, University of Arizona, Tucson, Arizona 85721-0041 Cite this: C…
A controlled fabrication of wire-like assemblies of cadmium sulfide (CdS) nanoparticles has been developed based on a template technique. Well-defined amphiphilic core−shell cylindrical polymer brushes were used as single molecule templates, utilizing the coordination of cadmium ions with carboxylate groups in the cor…
Tensile tests were carried out on free-standing composite films of poly(vinyl alcohol) and six different types of carbon nanotubes for different nanotube loading levels. Significant increases in Young's modulus by up to a factor of 2 were observed in all cases. Theories such as the rule-of-mixtures or the Halpin-Tsai-…
Abstract Hyperbranched poly(ethyl methacrylate)s (PEMA) were prepared by quasi‐living radical copolymerization of 2 ‐( N , N ‐diethylaminodithiocarbamoyl)‐ethyl methacrylate (inimer: DTEM) with ethyl methacrylate (EMA) under UV irradiation. DTEM monomers play an important role in this copolymerization system as inimer…
In a series of three papers we present the results of surface structure analysis of anisotropic polymer films using ATR-IR spectroscopy. In the first paper, the methodology for quantitative ATR-IR analysis of optically biaxial polymer films of orthorhombic symmetry is outlined, and results are presented of the first s…
Abstract Polyglactin was successfully synthesized by the melt/solid polycondensation of a mixture of glycolic acid (GA) and L ‐lactic acid (LA) mostly at a GA to LA monomer ratio of 90/10. In the polymerization procedure, a solid polycondensate was first prepared by melt‐polycondensation at 150–190 °C, mechanically cr…
Abstract The photooxidative degradation of blends (in a full range of compositions) of amorphous poly(vinyl chloride) (PVC) with semicrystalline poly(ethylene oxide) (PEO) in the form of thin films is investigated using absorption spectroscopy (UV–visible and Fourier transform infrared) and atomic force microscopy (AF…
Molecular structures of alumina nanoballs and nanotubes have been determined. Tetrahedral, octahedral, and icosahedral alumina nanostructures were derived from Platonic solids and Archimedean polyhedra and were optimized by quantum chemical methods. I(h)-symmetric balls, resembling their isovalence electronic analogue…
Abstract Biodegradable, amphiphilic, four‐armed poly(ϵ‐caprolactone)‐ block ‐poly(ethylene oxide) (PCL‐ b ‐PEO) copolymers were synthesized by ring‐opening polymerization of ethylene oxide in the presence of four‐armed poly(ϵ‐caprolactone) (PCL) with terminal OH groups with diethylzinc (ZnEt 2 ) as a catalyst. The che…