不同波长脉冲LED光源的频率和占空比对植物光合速率和光碳能力的影响

Effects of the Frequency and Duty Cycle of Pulse LED Light Sources with Different Wavelengths on Plant Photosynthetic Rate and Photocarbon Capacity

本文分析了脉冲发光二极管(LED)光源的研究进展,制作了不同波长的脉冲LED光源面板;测量了灯面板下方25 cm处光合光子通量密度(PPFD)随光源波长、频率和占空比的变化;在固定光源工作周期条件下,研究了光合速率随频率的变化,发现在不同波长下,植物光合速率具有最佳频率;在固定光源频率条件下,研究了光合速率随占空比的变化,发现在不同的占空比下,植物的光合速率有其最佳的占空周期;由于在固定频率或固定占空比条件下,其PPFD不能随着占空比和频率的变化而保持恒定,因此提出了光碳能力的概念(光碳能力=光合速率⋅PPFD^(-1)=Pn⋅PPFD^(-1),其中Pn为光合速率,其生物学意义是一个光子能量转换多少二氧化碳分子进行光合作用);在固定光源占空比条件下,研究了光碳能力随频率的变化。每种光源,均有对应优化的频率,对应得到此种光源下最大的光合速率;每种光源,均有对应优化的频率,对应得到此种光源下最大的PPFD;每种光源,均有对应优化的频率,对应得到此种光源下最大的光碳能力。本文通过提出光碳能力来衡量植物光照参数与碳减排量之间的对应的关系,希望以后光学设计可以通过优化此参数获得最优化的光照条件来获得最经济的碳减排量。

This article analyzes the research progress of pulsed light emitting diode(LED)light sources and aims to produce different wavelength pulse LED light source light panels,and to measure the variation of photosynthetic photon flux density(PPFD)at 25 cm below the lamp panel with the change of wavelength,frequency,and duty cycle of the light source.Under the condition of fixed light source duty cycle,the variation of photosynthetic rate with frequency was studied,and it was found that under different wavelengths,the plant photosynthetic rate had its respective optimized frequency;under the condition of fixed light source frequency,the variation of photosynthetic rate with duty cycle was studied,and it was found that under different duty cycles,the plant photosynthetic rate had its respective optimized duty cycle.Because its PPFD cannot be kept constant with the change of duty cycle and frequency under the condition of fixed frequency or duty cycle,the concept of photocarbon capability is proposed with photocarbon capability=photosynthetic rate⋅PPFD^(-1)=Pn⋅PPFD^(-1),its biological significance is how many carbon dioxide molecules can be stimulated by a photon energy to photosynthesis.Under the condition of fixed light source duty cycle,the variation of photocarbon capacity with frequency change was studied.Each type of light source has a corresponding optimized frequency,corresponding to the maximum photosynthetic rate under this type of light source;each type of light source has a corresponding optimized frequency,corresponding to obtaining the maximum PPFD under this type of light source;each type of light source has a corresponding optimized frequency,which corresponds to the maximum photocarbon capacity under this type of light source.This article proposes a method to measure the corresponding relationship between plant lighting parameters and carbon reduction by proposing light carbon capacity.It is hoped that in the future,optical design can achieve the most economical carbon reduction by optimizing this parameter to obtain the optimal lighting conditions.