The researchers studied how the photosynthesis of Ningxia ZiZyphus jujube leaves changes throughout the day and how it is influenced by environmental factors like sunlight, temperature, and humidity. They found that the photosynthetic rate of the plant had two peaks during sunny days, with a midday dip caused by stomatal factors. The equation that best described the photosynthetic rate included factors like sunlight, air temperature, leaf temperature, CO2 levels, and humidity. Overall, air temperature and humidity had the biggest impact on the photosynthetic rate, while other factors indirectly affected it.