|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 1999 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1998 : ¥2,300,000 (Direct Cost : ¥2,300,000)
Nonlinear chemical reaction systems show various interesting behavior such as chemical oscillations and multistability due to autocatalytic reactions inherent in the system. Response of these systems to the light illumination has not so far been studied extensively although it is expected to be very interesting . Paying attention to this fact, we have continued the research work on the response of the chemical oscillator systems to the stationary light illumination. On the other hand, the pulse-light illumination experiment throws light upon the transient response of the system, giving rise to interesting phenomena such as excitability or phase shift of oscillations, In the case of excitable media, the response to a pulsed light has a threshold, above which the response is independent of the perturbing light intensity. This characteristic behavior of the nonlinear chemical reaction systems, together with chaotic behaviors of the system, is important in relation to mechanisms of the living organism.
In the present study, we studied the Belousov-Zhabotinsky system, the Minimal bromate oscillators, and the pH oscillators, in which the system pH shows up oscillations, by illuminating a flow cell with a pulse light to fix the region of excitability on the state diagram. We have also studied the phase shift of oscillations by applying a pulse light to an oscillating system, The results given here include also the dark and stationary-light experiments which we have newly developed, They are important as they give a basic information for future studies to clarify the nature of their response to pulsed light.