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1.
R. Murgan F. Razak D. R. Tilley T. Y. Tan J. Osman M. N. A. Halif 《Computational Materials Science》2004,30(3-4):468-473
We derive an expression for transmittivity (TSHG) of second harmonic generation (SHG) signals from a ferroelectric (FE) film. Intensities of up and down fields in the medium are investigated in relation to TSHG. The derivations are made based on undepletion of input fields and nonlinear wave equation derived from the Maxwell equations. We present two cases: film without mirrors and with partial mirrors. Expressions for the newly derived nonlinear susceptibility coefficients of SHG for real crystal symmetry [J. Opt. Soc. Am. B 19 (2002) 2007] are used to get more realistic results. Variations in TSHG with respect to film thickness are illustrated. 相似文献
2.
Maher M. Osman Mounir M. Abd El-Malek Aida B. Tadros Atef M. Michael 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,62(1):46-52
4-Amino-3-thio-1,24-triazolidine (L1) and 4-amino-5-thio-1,3,4-thiadiazole (LII) as well as their metal complexes of the general formulae MLI·2H2O and MLIICl (M; Pb(II), Cd(II) and Zn(II)) were prepared. With Sn(II), we obtained Sn(LI)2·2H2O and SnLIICl, respectively. The structures of the compounds were identified through elemental analysis, and IR and UV spectra measurements, in addition to thermal analysis in case of the metal complexes. The antifouling properties of the compounds were tested by their incorporation into paint formulations which were applied to PVC substrates and tested in water from Alexandria western harbour. When the compounds were added at 17·5% by volume, the coated panels were fouled after 3 months of immersion. The addition of 6·7% by volume of tributyltin oxide to 15·8% of the prepared compounds in one formulation elevated the paint efficiency and prevented fouling for 11 months. Paint containing solely tributyltin oxide at the same concentration was inactive against algae. 相似文献
3.
Rinkenauer Gerhard; Osman Allen; Ulrich Rolf; Müller-Gethmann Hiltraut; Mattes Stefan 《Canadian Metallurgical Quarterly》2004,133(2):261
Lateralized readiness potentials (LRPs) were used to determine the stage(s) of reaction time (RT) responsible for speed-accuracy trade-offs (SATs). Speeded decisions based on several types of information were examined in 3 experiments, involving, respectively, a line discrimination task, lexical decisions, and an Erikson flanker task. Three levels of SAT were obtained in each experiment by adjusting response deadlines with an adaptive tracking algorithm. Speed stress affected the duration of RT stages both before and after the start of the LRP in all experiments. The latter effect cannot be explained by guessing strategies, by variations in response force, or as an indirect consequence of the pre-LRP effect. Contrary to most models, it suggests that SAT can occur at a late postdecisional stage. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
BT Heelan S Osman A Blyth L Schnorr T Jones AJ George 《Canadian Metallurgical Quarterly》1998,66(8):1101-1103
BACKGROUND: We investigated the potential of predicting allograft rejection by measuring the ability of graft-infiltrating cells to take up 2-[18F]fluoro-2-deoxyglucose ([18F]FDG). This molecule is a positron emitting glucose analogue that is taken up by metabolically active cells and can be detected using positron emission tomography. METHODS: Uptake of [18F]FDG during an alloresponse was measured both in vitro in mixed lymphocyte cultures and in vivo using allogeneic and syngeneic skin grafts. RESULTS: Uptake of [18F]FDG was seen in a mixed lymphocyte reaction. Using a mouse skin graft model, we found that mean [18F]FDG uptake was 1.5-2 times higher in allografts than in syngeneic grafts; the increase in uptake correlated with the level of T-cell infiltrate seen histologically. CONCLUSION: Assessing the metabolic activity of graft-infiltrating cells with [18F]FDG may be useful in the prediction of graft rejection episodes. 相似文献
5.
A. M. Abousehly A. M. Abou-El-Azm M. H. Wasfy A. A. El-Sharkawy M. B. Osman 《Journal of Materials Science》1990,25(1):431-433
The thermal properties: specific heat capacity (C
p), thermal conductivity (), and thermal diffusivity (a) of the glass system 77% B2O3-23% PbO doped with ZnO, were measured in the temperature range 300 to 700 K. It was found that electronic conduction has no significant contribution to the thermal conductivity. The main mechanism of heat transfer is therefore due to both phonons and photons. A discussion of the results is made in view of various theoretical aspects. 相似文献
6.
El-Mansy M. A. M. Suvitha A. Osman W. Khaled Khaled F. 《Journal of Computational Electronics》2021,20(6):2387-2402
Journal of Computational Electronics - Density functional theory as well as molecular mechanics force field (MMFF94) techniques are used to study intermolecular/intramolecular interactions, band... 相似文献
7.
M. U. Ahmad S. K. Husain S. M. Osman 《Journal of the American Oil Chemists' Society》1981,58(6):673-674
Seed oil ofPhyllanthus niruri (Euphorbiaceae) contains 1.2% ricinoleic (12-hydroxy-cis-9-octadecenoic) acid, previously unknown in the genusPhyllanthus. Identification is based on thin layer and gas liquid chromatography, infrared, nuclear magnetic resonance, and mass spectrometry
analysis as well as chemical methods. Other major components of the oil are linoleic acid (21%) and linolenic acid (51.4%).
Presented at the ISF/AOCS World Congress, April 1980, New York City. 相似文献
8.
The proliferation of digital media has led to a huge interest in classifying and indexing media objects for generic search and usage. In particular, we are witnessing a colossal growth in digital image repositories that are difficult to navigate using free-text search mechanisms, which often return inaccurate matches as they in principle rely on statistical analysis of query keyword recurrence in the image annotation or surrounding text. In this paper we present a semantically-enabled image annotation and retrieval engine that is designed to satisfy the requirements of the commercial image collections market in terms of both accuracy and efficiency of the retrieval process. Our search engine relies on methodically structured ontologies for image annotation, thus allowing for more intelligent reasoning about the image content and subsequently obtaining a more accurate set of results and a richer set of alternatives matchmaking the original query. We also show how our well-analysed and designed domain ontology contributes to the implicit expansion of user queries as well as the exploitation of lexical databases for explicit semantic-based query expansion. 相似文献
9.
J. Mustafa M. S. Ahmad Jr. A. Rauf S. M. Osman 《Journal of the American Oil Chemists' Society》1990,67(12):937-939
Branched-chain thioethers have been prepared from methyl 4-oxo-trans-2-hexadecenoate and 9,12-dioxo-trans-10-octadecenoic acid. The reagents involved in these preparations were mercaptoacetic and mercaptopropionic acids. The yields
of these thioethers are almost quantitative. 相似文献
10.
R. S. Farag S. A. Osman S. A. S. Hallabo A. A. Nasr 《European Journal of Lipid Science and Technology》1981,83(2):62-65
The oxidation of refined cotton seed oil catalysed by various α-amino acids and albumin have been studied in aqueous and non-aqueous media. Cysteine, phenylalanine and albumin possessed pro-oxidant effect in cotton seed oil in aqueous and non-aqueous media. Serine exhibited pro-oxidant activity in aqueous media and minor anti-oxidant effect in non-aqueous media. The effectiveness of the amino acids on cotton seed oil oxidation was in the following descending order in both aqueous and non-aqueous media: cysteine > phenylalanine > serine. The pro-oxidant effect in aqueous media might be due to the predominant presence of the protonated amino nitrogen. Whilst, amino acid-metal complex might be responsible for the pro-oxidant effect in non-aqueous media. 相似文献