Direct solar drying has been widely used as the simple structure, easy manufacturing, and portability. The surface of the material is prone to overheating due to direct exposure to strong light radiation. Mechanical ventilation has been used to improve the drying quality. Shade mesh can be installed to reduce air temperature and excessive light on materials. However, the available solar energy can be reduced at the same time. In addition, the ventilation equipment is typically powered by photovoltaic cells. Most solar radiation energy is converted into heat energy and directly dissipated due to the limitation of the bandgap width of semiconductor materials. Solar energy cannot be fully utilized for drying. Overall, there is a low value in the comprehensive utilization rate of solar energy in the drying systems. It is often required to improve the utilization rate of solar energy for high-quality drying materials. In this study, spectral splitting technology was applied for direct solar drying. The solar spectrum was split into two components at 640 nm. Specifically, the 280-640nm band was reflected into the photovoltaic cell for the direct power generation, while the 640-2 500 nm band was transmitted into the interior of the drying chamber to raise the temperature of the air. A systematic investigation was implemented to explore the effects of direct solar drying, solar shade drying, and spectral splitting solar drying on the drying time, drying efficiency, color difference, nutritional composition, and microstructure of mulberry leaves. Additionally, the electrical performance of the photovoltaic module was also evaluated to determine the comprehensive utilization rate of solar energy. The experimental results show that the drying efficiency of direct solar drying (7.93%) was close to that of spectral splitting solar drying (7.84%), both of which were higher than that of solar shade drying (3.79%); In view of the exposure to intense light and high temperatures, the worst quality of mulberry leaves was found after direct solar drying, with a color difference of 24.39, a large loss of nutrients, and serious shrinkage and deformation of epidermal cells; The color differences of mulberry leaves were 12.01 and 11.33 after solar shade drying and spectral splitting solar drying, respectively. There were high retention rates of nutrients and bioactive compounds, along with minimal shrinkage in microstructure. Therefore, both solar shade drying and spectral splitting solar drying enhanced the mulberry leaf quality. The biological effects of the red light on the mulberry leaves after spectral splitting solar drying also outperformed those after solar shade drying in the quality metrics, such as the color difference and chlorophyll contents; The spectral splitter photovoltaics received less solar energy, with the 11.47% increase of photoelectric conversion efficiency. While the photoelectric conversion efficiency of conventional photovoltaics was only 5.67%, due to the high temperature and light-induced degradation. There was the best quality of mulberry leaves after spectral splitting solar drying, with a solar energy utilization rate of 10.61%. This finding can provide the technical support to improve the quality of solar drying products and the utilization rate of solar energy.

In order to reduce the labor intensity and improve the efficiency of pruning, this study designed a multi-section luffing apple pruning equipment suitable for apple orchards in hilly and mountainous areas of China. In the essay, the structure and working principle of the equipment are expounded, the cutter was analyzed, and the parameters were determined. Using the self-made test bench to simulate the field experiment, this study selected the ratio of cutting speed to feeding speed and feeding speed as the influencing factors and took the cut-off rate, cutting efficiency and cutting power as the objectives to carry out single factor experiment and quadratic regression orthogonal experiment. The test results show that the cutting power increases with the increase of ratio of cutting speed to feeding speed, and the cut-off rate and cutting efficiency first increase and then decrease. As the feeding speed increases, the cutting efficiency and power increase, and the cut-off rate decreases. When the cut-off rate was greater than 80%, the optimal combination of operating parameters was the feeding speed of 0.55 m/s and ratio of cutting speed to feeding speed of 1.29. Under this combination, the cut-off rate was 84.9%, the cutting efficiency was 13.1, and the cutting power was 175.7 W. The error between the predicted target value of the model and the average measured target value was less than 7%, so the test results are reliable. According to the obtained optimal operating parameters, the actual cutting experiment of the pruning equipment in the field was carried out, and the cutting rate was 96.3%, which meet the design requirements. This study can also meet the needs of mechanized pruning of fruit trees with different crown shapes, improve the applicability of pruning equipment, and provide support for the development of mechanized pruning equipment in China.