Project/Area Number |
63540286
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Research Category |
Grant-in-Aid for General Scientific Research (C)
|
Allocation Type | Single-year Grants |
Research Field |
物理学一般
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Research Institution | Shizuoka University |
Principal Investigator |
NAGASHIMA Hiroyuki Shizuoka University, Faculty of Liberal Arts, Professor, 教養部, 教授 (20015811)
|
Project Period (FY) |
1988 – 1990
|
Project Status |
Completed (Fiscal Year 1990)
|
Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1990: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1989: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1988: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
Keywords | Belousov-Zhabotinsky reaction / Reaction-diffusion system / Target pattern / Pacemaker / Wave propagation / 計算機シミュレ-ション / ファンデルポ-ル振動子 / レスラ-モデル / Belousov-Zhabotinsky反応 / 非平衡開放系 / 散逸構造 / 非線形力学 / 非平衡解放系 / カオス |
Research Abstract |
Results are summarized as follows : 1) an experimental method was developed to control wavelength of a target pattern by strength of the pacemaker. The mechanism of the control is qualitatively explained by a reduced equation from a general reaction-diffusion system. The phenomena can be reproduced by numerical computation by using the van der Pol equation. From the experimental point of view, it is remarkable to be able to control the wavelength of the target pattern in such a simple way. 2) collapse of target patterns was observed. At first it was found by chance when a target pattern was forming. Since the collapse occurs very drastically and the whole pattern disappears in a few seconds, it is not certain whether the phenomena can be interpreted within the framework of the usual reaction-diffusion system or not. 3) new types of waves are found numerically. One of the waves is so-called a 'measuring worm wave', whose wave surface does not move smoothly but discontinuously at regular intervals. 4) finally we mention the numerical results of chaotic reaction-diffusion system. Target patterns are observed in a diffusion-coupled Rossler system when the frequency is lower than that of the outer medium. The pattern is confirmed to be stable when small perturbaitons are added to the system.
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