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Eric Schechter 《Journal of Differential Equations》1981,39(3):413-425
We consider the maximal solution of , where ? satisfies a one-sided variant of Carathéodory's conditions. A best-possible condition is proved for the dependence of u on ?. Also we show that a function v satisfies if and only if v is dominated by the maximal solution u. 相似文献
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A non-destructive and non-invasive method for quantitative characterization of parchment deterioration, based on spectral
measurements, is proposed. Deterioration due to both natural aging (ancient parchments) and artificial aging (achieved by
means of controlled UV irradiation and temperature treatment) was investigated. The effect of aging on parchment native fluorescence
was correlated with its deterioration condition. Aging causes fluorescence intensity drop, spectral shift of the main peak,
and an overall change in the fluorescence spectral features. Digital color imaging analysis based on visible reflectance from
the parchment surface was also applied, and the correspondent color components (RGB) were successively correlated with the
state of parchment deterioration/aging. The fluorescence and color imaging data were validated by analysis of historical parchments,
aged between 50 and 2000 years and covering a large variety of states of deterioration. The samples were independently assessed
by traditional microscopy methods. We conclude that the proposed optical method qualifies well as a non-destructive tool for
rapid assessment of the stage of parchment deterioration. 相似文献
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Enhanced electro-catalytic degradation of chloroorganic compounds in the presence of ultrasound 总被引:2,自引:0,他引:2
The application of finely divided (black) Pd and Pd-Fe powder in the sono-electro-catalytic reduction of chlorophenoxy herbicides (2,4-D) and chlorophenols (2,4-DCP) in aqueous solutions allows for effective destruction of toxic chlorinated aromatic compounds. At 20 degrees C complete conversion of these compounds is observed within 10 min. On bimetallic Pd/Fe catalyst, intermediates due to the oxidation reaction are detected in addition to the products of dechlorination. The bimetallic catalyst appears to be energetically and economically superior to the Pd. In both cases, the reaction times were considerably shortened in comparison with traditional electro-catalytic processes. 相似文献
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Sluszny C Gridin VV Bulatov V Schechter I 《Fresenius' Journal of Analytical Chemistry》2001,370(1):69-75
Successful coupling of imaging microscopy with Fourier transform spectrometry provides a new methodological approach. This was applied to the direct analysis of particulate deposits of polycyclic aromatic hydrocarbons (PAHs). The fluorescence signals of single microscopic particulates were found to be proportional to their mass, obtained from the corresponding HPLC results. Special fluorescence characteristics related to individual particle analysis were studied. The sensitivity of the proposed method to PAHs in soil is in the sub-ppb range, similar to HPLC results. Analysis of inhomogeneous PAH-particulates was demonstrated, as well as the resolution of photochemical products of PAHs. The effects of particulate orientation relative to the detector upon quantification are discussed. 相似文献