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Photochemical thermal lens spectroscopy .3. the determination of phosphorus and siliconстатья
Информация о цитировании статьи получена из
Web of Science
Дата последнего поиска статьи во внешних источниках: 27 мая 2015 г.
- Авторы: GRISHKO VI, GRISHKO VP, KUZYAKOV YY
- Журнал: SIBIRSKII KHIMICHESKII ZHURNAL
- Номер: 1
- Год издания: 1992
- Первая страница: 115
- Последняя страница: 124
- Аннотация: The paper deals with the thermal lens determination of phosphorus and silicon when being photoreduced their molybdenic heteropolyacid at beam of laser used for absorption measurement. Two various absorption measurement thermal lens schemes were proposed to allow both the kinetic thermal lens measurement and equilibrium thermal lens signal that. Time resolution of kinetic measurement is no worse that 1.3 . 10(-7) s. The blank value was generally determined with ammonium molybdate photoreduction, which was being poorly extracted, but being taken in the great excess according to the routine spectrophotometric procedure. Thermal lens signal reached its equilibrium value for the time of less than 1 minute. The thermal lens equilibrium signal monitoring (probe laser) dependence and that of automonitoring (excite laser) on laser output power and pulse frequency were investigated. If molybdophosphoric acid being photoreduced, estimated quantum yield was 0,08 (excimer laser; 308 nm); 0,045 (nitrogen laser; 337,1 nm); 0,015 (He-Cd laser; 441,6 nm) and 0,001 (argon laser; 488,0 and 514.5 nm). Thermal lens equilibrium graph vs a temperature can hardly be explained, so that is the superposition of medium optical parameters temperature functions and the dark stages reaction rates. The better metrological characteristics were ensured from thermal lens monitoring curves in comparison with the spectrophotometric registration. The calibration curve was pictured in the coordinates of photoreduction reaction initial rate vs unknown concentration. The rate constant of molybdophosphoric acid photoreductions in butanol was equal to 2,0 s-1; and that of dark relaxation was equal to 0,4 s-1 (He-Cd laser with 14 mW output power). The mutual kinetic effect was noticed in being presence P and Si together.
- Добавил в систему: Кузяков Юрий Яковлевич