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Please use this identifier to cite or link to this item: https://elib.bsu.by/handle/123456789/206558
Title: Низкотемпературные фотопреобразования соединений уранила в твердой фазе
Other Titles: Low temperature phototransformation of the solid state uranyl compaunds / VI.Pakatashkin
Authors: Покаташкин, В. И.
Issue Date: 1999
Publisher: Минск : БГУ
Citation: Взаимодействие излучений с твердым телом: Материалы III междунар. науч. конф., 6-8 окт. 1999 г., Минск: В 2 ч. Ч.2. — Мн.: БГУ, 1999. — С. 84-86.
Abstract: Изучено твердофазное преобразование солей уранила при мощном оптическом, в частности, ультрафиолетовом возбуждении. Облучение образцов моногидрата уранилформиата и натрийуранилацетата проводилось при температуре жидкого азота. Образованные центры окраски имеют характерный цвет и стабильны во времени. Фотоактивность моногидрата уранилформиата значительно выше активности натрийуранилацетата при одинаковых условиях возбуждения. При растворении облученных образцов в воде происходит выпадение осадка, спектроскопические свойства которого отличаются от исходного вещества. Хранение выпавшего осадка при свободном доступе кислорода приводит к его окислению до состояния первичной необлученной соли уранила.
Abstract (in another language): Interaction of electromagnetic radiation with a solid body at a level of photochemical reactions has been not fully studied. The interaction of crystalline uranyl-ion complexes with intensive optical radiation has practical interest. Very few salts of uranyl are known, having phototransformation under uv radiation. We have studied the photoinduced transformations in UO 2 (HCOO)2i H2O and NaU02(CH3 C 0 0 )3 at 77K. Interaction of a laser radiation with fine-crystalline samples of these compounds leads to stable colour centres. An effect on mother substance of the radiation was estimated by a change of relative luminescence quantum yield and by decrease of decay time of a luminescence. The photosensitivity of the uranyl formiate monohydrate was considerably above than that of the sodium uranyl-acetate. Unirradiated uranyl salts are soluble in water. Having been intensively irradiated salts of both compounds at dissolution in water gave identical sediments. Filtered sediments at storage on air turn to mother substance of sodium uranyl-acetate or uranyl formiate monohydrate, which were identified by their luminescence spectra. Thus a selfcontained reduction - oxidizing cycle takes place. The main element of the cycle is a photoinduced reaction of recovering of the hexavalent uranium to the quadrivalent under high level radiation. The compound of quadrivalent uranium acidifies to five-valent form when being dissolved in water. The storing of the sediment at the presence of oxygen of air and light leads to further oxidating to the hexavalent form.
URI: http://elib.bsu.by/handle/123456789/206558
ISBN: 985-445-237-9
Appears in Collections:1999. Взаимодействие излучений с твердым телом

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