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 crystallization behavior and stoichiometric changes of barium titanium alkoxide‐derived monolithic gels prepared by the sol‐gel process using a high‐concentration Ba 2 Ti precursor solution (0.8 mol/L) were investigated during aging at room temperature. Crystallization of the gels (which were amorphous, per X‐ray…
An extrusion system that can create a polymer/gas solution rapidly for continuous processing of microcellular plastics is presented. Microcellular plastics are characterized by cell densities greater than 109 cells/cm3 and fully grown cells smaller than 10 μm. Previously these microcellular structures have been produc…
Among the nonthermal effects of ultrasound, acoustic cavitation may have the highest potential for therapeutic applications if it can be somehow controlled. Recent in vitro and in vivo experiments have demonstrated that sonochemically active cavitation can be enhanced an order of magnitude by superimposing the second…
The 9 methionine residues of vertebrate calmodulin (CaM) were individually changed to glutamine residues in order to investigate their roles in enzyme binding and activation. The mutant proteins showed three classes of effect on the activation of smooth muscle myosin light chain kinase, CaM-dependent protein kinase II…
UDP-galactose 4-epimerase from Escherichia coli catalyzes the interconversion of UDP-glucose and UDP-galactose. In recent years, the enzyme has been the subject of intensive investigation due in part to its ability to facilitate nonstereospecific hydride transfer between beta-NADH and a 4-keto hexopyranose intermediat…
An interferometric technique was developed to characterize in real time the etching rate of glasses with <100-nm resolution. The interferometer can be used to help reveal the charge distribution in poled glass.
A first order orientational transition, characterized by a 90\ifmmode^\circ\else\textdegree\fi{} azimuthal rotation of the surface easy direction, is reported for nematic liquid crystals (NLCs) anchored on self-assembled monolayers (SAMs). The SAMs are formed from alkanethiols [$\mathrm{C}{\mathrm{H}}_{3}{(\mathrm{C}{…
The earth's vast and varied cold environments could be rich sources of psychrophilic microorganisms growing at 5°C or below. Unfortunately, the diversity, physiology and potential of these organisms have largely been overlooked. This article focuses on psychrophiles and their cold-active enzymes and emphasizes how fut…
A three-dimensional (3D) dislocation simulation has been developed in the last few years in order to fill the gap between atomistic simulations and the more macroscopic approaches. The specific role of such a simulation is to combine all mechanisms responsible for the hardening (e.g. the forest mechanism) and the mult…
A novel two-region formulation of the rigorous electromagnetic boundary element method (BEM) is developed and applied to practical diffractive cylindrical lenses of continuous profile and with discrete levels (32, 8, and 2). The performance of these diffractive lenses is presented for incident waves of TE and TM polar…
A spin-coated thin polystyrene film on a silicon single crystal has been studied using the X-ray reflectivity technique. Signature of layering as a function of depth, due to confinement, in this polystyrene film could be detected from the reflectivity profile using a new analysis scheme. Small variations of electron d…
It has recently been considered that free radicals are closely involved in the pathogenesis of Parkinson's disease (PD), and the level of nitric oxide radical (.NO), one of the free radicals, is reported to increase in PD brain. In the present study, we established a direct detection system for .NO in an in vitro .NO-…
We have performed neutron diffraction experiments on deuterated propylene glycol, an organic glass former, at temperatures ranging from where its dynamical response approaches that of normal liquids to below the point where relaxation times appear to diverge. Our studies extend over a very broad range of scattering wa…
Grown-in defects detected by IR laser scattering tomography (LSTDs) in Czochralski-grown Si crystals were identified for the first time by transmission electron microscopy (TEM) with a special defect positioning technique. The basic structure of each LSTD was revealed to be a composite of two or three incomplete octah…
Experiments claiming a sharp decrease in the radioactivity of tritium incorporated in small monocrystalline particles of titanium have been reported and are described here in more detail Additional evaluation provides a high degree of evidence for the decrease in the radioactivity of tritium. A first attempt is made t…
The three-dimensional structure of the serine protease subtilisin BPN' (SBT) has been refined at 1.6 A resolution in space group C2 to a final R value of 0.17. 17 regions of discrete disorder have been identified and analyzed. Two of these are dual-conformation peptide units; the remainder involve alternate rotamers o…
The kinetics of thermal oxidation of H. C. Starck M‐11 and Ube SN‐E10 Si 3 N 4 powders was evaluated in the temperature range 650°‐1200°C using isothermal and nonisothermal thermogravimetric analysis, high‐resolution transmission electron microscopy, and X‐ray photoelectron spectroscopy. Between 700° and 1200°C, the i…
In the atmospheric corrosion of copper, nickel, and iron, adsorption of water affects corrosion rates. Knowledge of water adsorption and metal oxyhydroxide formation is important in understanding the atmospheric corrosion process. Gold provides a model system because it retains its surface characteristics throughout a…
When the arc vaporization of carbon rods in a helium atmosphere is conducted in the presence of small amounts of pyrrole, not only does one form nitrogen-doped fullerenes, but also the surface of the carbon rods becomes coated with a layer of a nitrogen-doped carbon. X-ray diffraction indicates d spacing expansion, an…
Photoemission and auger spectroscopies electron energy loss spectroscopies (e,2e) spectroscopy electron diffraction techniques absorption spectroscopies future developments.