Materials Literature
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The authors describe a simple control for a permanent motor drive that provides a wide speed range without use of a shaft sensor. Two line-to-line voltages and two stator currents are sensed and processed in analog form to produce the stator flux linkage space vector. The angle of this vector is used in a microcontrol…
Abstract Die Verbindungsklasse der Metall‐Sauerstoff‐Clusteranionen ist nicht nur einzigartig hinsichtlich ihrer topologischen und elektronischen Vielfalt — sie hat auch erhebliche Bedeutung für ganz unterschiedliche Disziplinen. So sind die früheren Arbeiten auf diesem Forschungsgebiet mit Namen wie Berzelius, Werner…
The reduction of CeO2 by hydrogen has been studied from 300–1200 K by several complementary techniques: temperature-programmed reduction (TPR) and magnetic susceptibility measurements, Fourier-transform infrared (FTIR), UV–VIS diffuse reflectance and X-ray photoelectron (XP) spectroscopy. Two CeO2 samples were used wi…
This paper reviews what is known about the structures and optical properties of point defects in silica glass and other amorphous forms of SiO2. The available structural information derives mainly from the results of electron spin resonance (ESR) spectrometry-a method which is directly applicable only to the subclass…
This article first provides a concise summary of the concepts, limitations, and paradigms of biological self-assembly processes, then surveys covalent self-assembly processes in the synthesis of 3-dimensional molecules and ordered assemblies
The present book is the result of diverse courses on diffusion. It is intended to give as complete an overview as possible of diffusion in solid media, while relating the process of diffusion to both their physical bases and their applications. A series of a real situations is covered in this account, from self-diffus…
Material-dependent properties influencing the performance of fiber amplifiers are reviewed together with the available data for Er/sup 3+/. The major glass types potentially useful in this application are considered and compared to silica. The topics addressed include quenching processes and the solubility of rare-ear…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTXPS studies of solvated metal atom dispersed (SMAD) catalysts. Evidence for layered cobalt-manganese particles on alumina and silicaBeng Jit Tan, Kenneth J. Klabunde, and Peter M. A. SherwoodCite this: J. Am. Chem. Soc. 1991, 113, 3, 855–861Publication Date (Print):January 1…
Basic Principles of Chemical Bonding. Chemical Reactions in the Gas Phase and in Simple Solvent Models. Chemical Reaction in All--Atom Solvent Models. Potential Surfaces and Simulations of Macromolecules. Modeling Reactions in Enzymes: An Introduction. General Acid Catalysis and Electrostatic Stabilization in the Cata…
Ceramic nanocomposites can be divided into three categories: intergranular nanocomposite, intergranular nanocomposite and nano/nano composite. The intra- and intergranular nanocomposites were found to show the two to five times higher toughness and strength at room temperature than those of monolithic materials. The h…
The ultraviolet–visible absorption spectra are given for 10 nm diameter colloidal particles of 52 of the metallic elements, calculated from the optical constants of the metals by means of Mie theory. For most of the elements the spectra cover the range 200–900 nm. Well resolved absorption bands are observed for colloi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNanometer-sized semiconductor clusters: materials synthesis, quantum size effects, and photophysical propertiesYing Wang and N. HerronCite this: J. Phys. Chem. 1991, 95, 2, 525–532Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published…
Abstract Inorganic metal–oxygen cluster anions form a class of compounds that is unique in its topological and electronic versatility and is important in several disciplines. Names such as Berzelius , Werner , and Pauling appear in the early literature of the field. These clusters (so‐called isopoly‐ and heteropolyani…
Volume 15 of Reviews in Mineralogy is written with two goals in mind. The first is to derive the 32 crystallographic point groups, the 14 Bravais lattice types and the 230 crystallographic space group types. The second is to develop the mathematical tools necessary for these derivations in such a manner as to lay the…
Volume 22 of Reviews in Mineralogy is a book exclusively devoted to three minerals: the Al2SiO5 polymorphs - andalusite, sillimanite, and kyanite. It covers a wide variety of topics that must be considered in the analysis of metamorphic systems and illustrates the fact that modern metamorphic petrology demands an awar…
A model assuming a non-continuous structure of glasses is established to interpret the inelastic neutron scattering and Raman scattering. The 'boson' peak in Raman scattering is related to the vibrational density of states 'excess'. These two related features are a result of vibrations localized in the blobs that comp…
The authors have formulated a polarized-orbital treatment of electron-atom scattering which includes dynamic distortion effects. Detailed formulae are given in terms of their previous formulation of the polarized-orbital method. Results for electron-helium scattering are presented and compared with various experimenta…
Using mechanical alloying and a subsequent two-step heat treatment we produced magnetically isotropic microcrystalline Sm2Fe17Nx samples with room-temperature coercivities up to 24 kA/cm (30 kOe). The remanence and the energy product are equivalent to similarly prepared Nd-Fe-B samples, but the properties at elevated…
A simple and accurate extended Jones matrix representation for the twisted nematic liquid-crystal display at the oblique incidence was obtained for the first time. The results obtained by this extended Jones matrix representation are quite close to those obtained by the faster 4×4 matrix method with spectrum averaging…
The authors propose a new method of series analysis in which the available series coefficients are fitted to an algebraic equation. Such a proposal restricts solutions to have algebraic singularities with rational critical exponents. The advantage of the method over the method of differential approximants is that in t…