| Project/Area Number |
01840016
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
物理化学一般
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| Research Institution | Gunma University |
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Principal Investigator |
SHIZUKA Haruo Gunma University, Department of Chemistry, Professor, 工学部, 教授 (40008454)
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| Co-Investigator(Kenkyū-buntansha) |
SAKIMUKAI Shinji Unisoku Co. Ltd., Research Associate, 研究員
MUGISHIMA Akio Unisoku Co. Ltd., Research Associate, 研究員
NAGAMURA Toshihiko Unisoku Co. Ltd., President, 社長
HIRATSUKA Hiroshi Gunma University, Department of Chemistry, Associate Professor, 工学部, 助教授 (00016156)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 1990: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1989: ¥5,200,000 (Direct Cost: ¥5,200,000)
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| Keywords | Near-infrared emission spectrum / Near-infrared absorption spectrum / Transient absorption spectrum / Germanium photodiode detector / Time resolved spectrofluorimeter / Lifetime measurement |
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| Research Abstract |
The purpose of this research is to construct a convenient spectrophotometer system which is able to measure the absorption and emission spectra of unstable intermediates such as radicals and triplet states in near-infrared region. Because of lack of a good detector in this region, it has been difficult to measure them quantitatively and therefore the spectroscopic study in near-infrared region has stayed in an undeveloped stage.
In this research, we tried to construct a spectrophotometer system which is able to measure absorption spectro and emission specctra in visible and near-infrared region, in combination with a Nd^<3+> : YAG laser system. A photomultiplier and a germanium diode were used as the detectors in visible and near infrared region, respectively. By studying the spectra of some laser dyes, it was confirmed that the expected data were obtained by the constructed spectrophotometer.
The ability of our system is as follows ;
(1) Spectral wavelength region is from visible to near infrared (400nm-1800nm).
(2) Time resolution is -20ns.
(3) The spectrophotometer system is controlled and the experimental data are processed by a microcomputer.
By use of our near-infrared spectrophotometer system, absorption and fluorescence spectra, and fluorescence lifetimes of semiquinone radicals of xanthone, benzoylnaphthone, dibenzilidene acetone and flavone produced in poly (vinyl alcohol) films by gamma-irraidation. Fist several absorption bands and therefore the fluorescence bands of these radicals are in near-infrared region. The long wavelength location is the reason why the fluorescence spectra of these radicals have not been measured until very recently.
We succeeded in measuring the fluorescence spectra of these radicals for the first time. It was also found that the fluorescence lifetimes of these radicals are shorter than the pulse width of laser excitation laser (8ns).
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