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。
Backscattering of radiation incident on a solid medium has been treated with some success as a reflection phenomenon. The concept of albedo has been used in the literature to deal with this problem. A Monte Carlo program has been used in this study to simulate the generation of bremsstrahlung beams from medical linear…
Some effective uses of the radial gradient-index (GRIN) lens in zoom lens systems are presented and lens design examples are shown. Also the effective Abbe number of a cemented GRIN lens is discussed and it is shown that a radial GRIN lens with uncommon dispersion can be replaced by a cemented radial GRIN lens with co…
Abstract Understanding the dynamics of soil K is important for the formulation of a sound fertilizer management strategy. Two experiments were conducted to determine the behavior of K in the soil after fertilization. Five rates of K (0 to 120 kg ha −1 ) were applied to two Typic Paleudults, a loam and a sandy loam, in…
Fouling cannot always be prevented; it is important to consider the design of fouling‐resistant heat exchangers. To examine these exchangers, a test fluid whose fouling behaviour is understood should be used. Experiments have been conducted to examine the response of two model systems, a pulsatile flow and a fluid bed…
Abstract Amorphous Nb 2 O 5 thin films are obtained by vacuum evaporation of high‐purity Nb 2 O 5 powders onto NESA glass substrates. These films were found to exhibit both photochromism and electrochromism. Reasonably good photochromic responses were observed in ethanol and in the N 2 atmosphere, but no photochromism…
The synthesis and nonlinear optical properties of a series of chiral pyrrolo[1,2-a]quinolines la-e is presented. The microscopic hyperpolarizabilities (beta(z)) were determined by EFISH measurements and the macroscopic susceptibilities (X2) were estimated by the Kurtz powder test. A small fixed angle of the annelated…
Comparatively little research has been published on radioactive contamination from nuclear medicine patients using hospital toilet facilities. The present study was undertaken to obtain an estimate of the amount of restroom contamination found in a typical 700-bed community hospital as a result of nuclear medicine pro…
We present the results of a dielectric investigation of two members of the 4-n-pentylphenyl-4′-n-alkyloxythiobenzoate ([nbar]S5) homologous series with n = 9 (9S5) and n = 10 (10S5), in the frequency range 0·1–10 MHz, and in the temperature range covering all of the liquid crystal phases. Some properties of the [nbar]…
Unstable superoxide, · O 2 - , and semiquinone can be stabilized when hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 is crystallized from aqueous solutions containing these radicals. The inorganic microcrystals surround the radicals and stabilize them for nearly a year at room temperature. Radicals adsorbed on the surface of a…
A theoretical model describing the behavior of a thermally thin cellulosic sheet heated by external thermal radiation in a quiescent microgravity environment is developed. This model describes thermal and oxidative degradation of the sheet and the heat and mass transfer of evolved degradation products from the heated…
Mullite composites toughened with ZrO 2 (with or without a MgO or Y 2 O 3 stabilizer) and/or SiC whiskers (SiC( w )) were fabricated by hot‐pressing powders prepared from Al, Si, Zr, and Mg(Y) alkoxide precursors by a sol–gel process. Micro‐structures were studied by using XRD. SEM, and analytical STEM. Pure mullite s…
Over the last twenty years, unified viscoplastic constitutive models have evolved to meet this need. These constitutive models provide a means for representing a material's response from the elastic through the plastic range including strain-rate dependent plastic flow, creep, and stress relaxation. Rate-dependent pla…
Abstract Messung der elektrischen Leitfähigkeit von Na 3 O(NO 2 ) und Na 3 O(CN) zeigen, daß beide Verbindungen bei Temperaturen zwischen 200° und 250°C eine sprunghafte Zunahme der Natrium‐Ionenleitfähigkeit aufweisen. Diese Effekte beruhen nicht auf Schmelzprozessen, wie die Phasendiagramme der entsprechenden pseudo…
Discusses the quality of fabrics and garment technology. Looks at the various types of material focusing particularly on the female market. Shows how new synthetic fibres have improved the feel of garments and that consumers, fashion designers and experts in finishing have all reached the same conclusion, that quality…
Dislocation structures and faults in vacuum-hot-pressed Be12Nb have been examined after compressive deformation at 1200[ddot]C. Both perfect and partial dislocations were observed in the deformed polycrystalline material. Most dislocations were found to be partials bounding planar faults in the grains characterized. S…
The two limits for modeling vibrating thin films, viz as a plate or as a membrane, are discussed. In terms of these limits the sources of experimental uncertanties are identified and the advantages of using films which can be modeled as membranes are explained. The mathematical formalism for treating films as vibratin…
Polarized infrared and optical reflectance spectroscopies were used to study the structural phase transition in the organic charge-transfer salt N-propylquinolinium ditetracyanoquinodimethane. Above the 220-K phase-transition temperature, the spectra are characteristic of other 1:2 semiconducting charge-transfer salts…
A liquid crystalline copolyester consisting of 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, with a composition (73:27) was studied as a melt processible, high temperature adhesive. The polymer was used as received without any additional treatment and was applied on an aluminum substrate as a film. The adhesiv…
Subtilisins are extracellular seryl-proteases produced by bacilli (Markland and Emil, 1971). In addition to signal sequences, these proteases have N-terminal extensions (pro-regions) which have also been identified in several other proteases (Silen et al., 1988; Vasantha et al., 1984; Polhner et al., 1987; Henderson e…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic structure of catalytically important palladium complexes studied by photoelectron spectroscopyF. Boekman, A. Gogoll, L. G. M. Pettersson, O. Bohman, and H. O. G. SiegbahnCite this: Organometallics 1992, 11, 5, 1784–1788Publication Date (Print):May 1, 1992Publicati…