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Dieter Hasselmann 《Nachrichten aus der Chemie》1984,32(11):970-974
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M. Bazin C. Hasselmann G. Laustriat R. Santus P. Walrant 《Chemical physics letters》1975,36(4):505-508
Hydrated electrons produced by photoionization of indole ring at 265 nm react with protonated imidazole leading to imidazole destruction. Such a reaction is also shown to occur in peptides and proteins. 相似文献
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Eric Marchioni Peter Horvatovich Bara Ndiaye Michel Miesch Claude Hasselmann 《Radiation Physics and Chemistry》2002,63(3-6):447-450
The application of the European Standards for the detection of irradiated food by thermoluminescence of silicates, electron–spin resonance spectroscopy of bones or gas chromatography–mass spectrometry of 2-alkylcyclobutanones does not allow the detection of irradiated ingredients included in small quantity in the matrix of a food which has not been irradiated, but which could be subjected to various processing technologies such as cooking, freezing or storage. The use of an enzymatic food hydrolysis carried out at moderated temperature, for the extraction of the food-contaminating silicate minerals and bone fragments, followed by a purification of the extracts by a high-density aqueous solution of sodium polytungstate, allows a simultaneous detection of weak inclusions (0.1% m:m) of irradiated spices and mechanically deboned turkey meat (MRM) included in various precooked foods. Moreover, the use of a supercritical fluid extraction procedure for the 2-alkylcyclobutanones or an additional purification step of the lipid extracts made it possible to lower the detection limit of the 2-alkylcyclobutanones radiation-induced from triglycerides. Using gas chromatography–mass spectrometry, down to 0.5% (m:m) of irradiated MRM included in non-irradiated chicken quenelles could be detected. 相似文献
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We present a functional renormalization group approach to the zero bias transport properties of a quantum dot with two different orbitals and in the presence of Hund's coupling. Tuning the energy separation of the orbital states, the quantum dot can be driven through a singlet-triplet transition. Our approach, based on the approach by Karrasch et?al (2006 Phys. Rev. B 73 235337), which we apply to spin-dependent interactions, recovers the key characteristics of the quantum dot transport properties with very little numerical effort. We present results on the conductance in the vicinity of the transition and compare our results both with previous numerical renormalization group results and with predictions of the perturbative renormalization group. 相似文献
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B Ndiaye P Horvatovich M Miesch C Hasselmann E Marchioni 《Journal of chromatography. A》1999,858(1):109-115
The inclusion of a purification step by silver ion chromatography in the EN 1785 analytical protocol for 2-alkylcyclobutanones (validated by the European Committee for Standardization for the detection of ionizing radiation treatment) has considerably improved the quality of the chromatograms obtained, allowing the detection of food samples irradiated at very low doses (0.1 kGy) or irradiated ingredients included in low proportions in non irradiated foodstuffs. This analytical modification of the protocol EN 1785 ought thus to permit a very considerable extension of its current field of application. 相似文献
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C. Hasselmann C. Pigault R. Santus † G. Laustriat ‡ 《Photochemistry and photobiology》1978,27(1):13-18
Abstract— An imidazole ring photodegradation induced by indole derivatives in oxygen-free aqueous solutions (Λexc = 254 nm) was demonstrated and studied in various systems at low concentration (0.2 m M ). The degradation rate was maximal in the indole-imidazole system and decreased when a substituent was present on either or both rings. The degradation rate also depended on pH (maximal at pH ˜ 6) and on imidazole concentration. Results obtained under N2 O atmosphere, in the presence and absence of 1 M t -butanol, indicate that the imidazole degradation is promoted by hydrated electrons photogenerated by the indole chromophore. Kinetic analysis of the data confirms this mechanism. 相似文献
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