Tом 6. Сводное содержание (2009)

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Памяти Юрия Яковлевича Ефремова

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T6N1

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Кандидаты на представление к званию «Почетный член ВМСО»

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Письмо в редакцию

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Дискриминация газовых компонентов и кластеров

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One of the serious problems in analytical mass spectrometry is the interferences between clusters and  gas components and components of sample. These interferences make parameters of mass spectral  analysis worse. The present paper describes a new approach for the reduction of such interferences  by using pulsed glow discharge which allows the temporal discrimination of interfering components.  Infl  uence of hydrogen on dynamic discrimination of various gas components is considered. It was  possible to decrease the relative intensity of gas and clusters components by several orders of magnitude. In particular, optimum conditions (pressure in discharge cell, addition of hydrogen, repelling pulse  delay) allow effective suppressing the  40 Ar + component which makes possible the measurement calcium  in metallurgical silicon.

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Оценка неопределенности измерения изотопного состава высокообогащенного 28Si

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A technique for uncertainty estimation of an isotopic composition of highly enriched silicon-28 in  the form of a single crystal, silicon tetrafl  uoride and silane by laser ionization mass spectrometry is  described. It is shown that the use of potassium as an internal standard limits the uncertainty of measurement due to the uncertainty of silicon isotopes tabulated abundances. It is found that interferences  of the ions  28 SiH+ on  29 Si + should be taken into consideration during direct measurements of isotopic  composition of poly- and single crystals of highly enriched silicon-28. The contribution of the  28 SiH+  to the  29 Si + peak intensity is estimated.

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Квадрупольный фильтр масс с малой низкочастотной временной гармоникой электрического поля

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Upper stability island created by auxiliary RF voltage with small amplitude and low frequency  ν =  ω/Ω = 1/10 is investigated. The possibility of operation of quadrupole mass fi  lter with high  transmission 50 % and high resolution about R0.1 = 3000 is demonstrated. Phase shift synchronization,  ion cooling by buffer gas in RF quadrupole, and time fl  ight through fringing fi  eld optimization are  required for achievement of such parameters.

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Масс-спектрометрическое изучение термолиза комплексов включения

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Thermolysis of inclusion complexes «β-cyclodextrin-benzene carboxylic acid» has been studied by  temperature-programmed desorption mass spectrometry. Thermal decomposition of inclusion compounds  was proved to proceed in two steps: the release of benzene carboxylic acid in molecular form from  inner hydrophobic cavity of β-cyclodextrin and thermal decomposition of β-cyclodextrin.

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О точности определения изотопного состава легких элементов

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The performance of isotope ratio mass spectrometry systems (GC-C-IRMS, EA-IRMS, TC/EA-IRMS,  DI-IRMS) with respect to dependence of δ13 C, δ15 N, δ18 O values on the amount of sample was presented.  Various amounts of gas, liquid and solid samples were used for introducing to the mass spectrometry  systems. The main reasons of non-linear dependence of measured isotope ratios on decreasing sample  amounts appeared to be the presence of water in the ion source, imperfect optimization of ion source,  and scattering of ions by molecules of gas-contaminants.

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