基于可变光脉冲诱导荧光的浮游植物光合作用参数测量系统设计

Design of Phytoplankton Photosynthetic Parameter Measurement System Based on Variable Pulse Induced Fluorescence

浮游植物光合作用参数的快速测量对水华和赤潮灾害预警及水体生态研究具有重要作用。针对高速重复脉冲(FRR)光合作用参数测量技术中由窄脉冲光源激发引起的高数据采样率问题,采用单光脉冲实现单周转模式激发,应用脉冲积分法实现弛豫模式微弱光脉冲信号检测,设计了基于可变光脉冲诱导荧光的浮游植物光合作用参数测量系统,将数据采样率需求由10 MS/s以上降低至1 MS/s。实现了浮游植物光系统II(PSII)功能吸收截面、PSII最大光化学量子产率以及QA-(还原后的初级电子受体)再氧化时间常数的快速测量。实验表明,测量结果的相对标准偏差均小于3%。

Rapid measurement of phytoplankton photosynthetic parameters is important for bloom and red tide prediction as well as water ecological research. In order to solve the problem of high data sampling rate caused by narrow pulse light source when the fast repetition rate （FRR） method is applied, a phytoplankton photosynthetic parameter measurement system based on variable pulse induced fluorescence is designed. The designed system utilizes a single pulse to realize the single turnover excitation mode, and employs pulse integration to implement weak light pulse signal detection in the relaxation mode. The data sampling rate can be reduced from higher than 10 MS/s to 1 MS/s. The functional absorption cross section of photosystem II （PSII）, maximum quantum yield of photochemistry in PSII, and QA （reduced primary electron acceptor） reoxidation time constant, can be measured rapidly. The relative standard deviation of the three parameters is less than 3 %.