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141.
The absorption and emission spectra of the three isomeric cyanoanilines have been investigated. Quantum yields and decay lifetimes are reported for both fluorescence and phosphorescence processes. It is shown that the lowest energy absorption band of p-cyanoaniline consists of two distinct electronic transitions of the 1π*←1π type, whereas, in the o- and m-cyanoanilines, the lowest energy absorption band consists of a single electronic transition of the 1π*←1π type. These conditions are consistent with absorption data, emission data and kinetic analyses. The largest ?P/?F ratio is exhibited by the p-cyanoaniline and this observation is rationalized. 相似文献
142.
The preparation of the relatively unknown 7-cis isomers of β-ionyl and β-ionylidene derivatives via one way sensitized geometric isomerization is described. These highly sterically crowded isomers, once prepared do not readily thermally revert back to the trans. But the trienes, at temperatures ≥ 100° undergo irreversible cyclization to cyclohexadienes. 7-cis Isomers of β-ionylideneacetone and acetaldehyde as well as higher tetraenes and pentaenes in this series could not be prepared by sensitized isomerization. Partial reduction of 7-cis-β-ionylideneacetonitrile isomers led to the preparation of 7-cis- and 7,9-dicis-β-ionylideneacetaldehyde; and methyl Grignard reaction with the same nitrile gave the triene-methyl ketones. 相似文献
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Shing-Tung Yau 《Mathematische Annalen》1975,212(4):317-329
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Whole‐cell‐based identification of electrochemically active bacteria in microbial fuel cells by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry 下载免费PDF全文
Lijuan Zhang Yan Gao Linke Lai Sam Fong Yau Li 《Rapid communications in mass spectrometry : RCM》2015,29(23):2211-2218
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Wun-Kai Wang Hua-Chiang Wen Chun-Hu Cheng Wu-Ching Chou Wei-Hung Yau Ching-Hua Hung Chang-Pin Chou 《Journal of Physics and Chemistry of Solids》2014
We used atomic layer deposition to form ZnO thin-film coatings on Si substrates and then evaluate the effect of pile-up using the nanoscratch technique under a ramped mode. The wear volume decreased with increasing annealing temperature from room temperature to 400 °C for a given load. Elastic-to-plastic deformation occurred during sliding scratch processing between the groove and film for loading penetration of 30 nm. The onset of non-elastic behavior and greater contact pressure were evident for loading penetration of 150 nm; thus, full plastic deformation occurred as a result of a substrate effect. We suspect that elastic–plastic failure events were related to edge bulging between the groove and film, with elastic–plastic deformation attributable to adhesion discontinuities and/or cohesion failure of the ZnO films. 相似文献