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The findings suggest that PPO and phenolic compounds may play a key role in the defence system of apple fruits against MC and CR.

To improve the efficiency of polysaccharide extraction, vacuum technology was used to breakdown the cell wall to extract polysaccharides from Lentinus edodes stipe, and the optimal parameters were optimized by response surface methodology. Then the antioxidant activities in vitro of the polysaccharides were evaluated. Results showed that the optimal conditions for polysaccharide extraction were temperature of 62°C, vacuum of 0.08 MPa, stirring speed of 1200 r/min, time of 25 min and material/liquid ratio of 1:26 (g/mL). Under these conditions, the yield of polysaccharide was 4.28%. The decolorization rate and deproteinization rate of polysaccharides treated by kaolin and hydrogen peroxide were higher than that of activated carbon. However, there was no significant influence on the polysaccharide retention rate, that was about 80%. Results also indicated that polysaccharide treated with activated carbon could obtain higher antioxidant activity.

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Double junction tandem solar cells consisting of two absorbers with designed different band gaps show great advantage in breaking the Shockley-Queisser limit efficiency of single junction solar cell by differential absorption of sunlight in a wider range of wavelengths and reducing the thermal loss of photons. Benefiting from the advantages of adjustable band gap and low cost of perovskite cells perovskite/crystalline silicon tandem solar cells have become a research hotspot in photovoltaics. We systematically reviewed the latest research progress of perovskite/crystalline silicon tandem solar cells. Focused on the structure of perovskite top cells intermediate interconnection layers and crystalline silicon bottom cells We summarized the design principles of high-efficiency tandem devices in optical and electrical aspects. We found that the optical and electrical engineering of each layer structure in perovskite/crystalline silicon tandem solar cells goes through the whole process of device preparation. We also summarized the challenges limiting the further improvement of the efficiency of the perovskite/crystalline silicon tandem solar cells and the conrrespoding measures including improving the balance between V_oc and J_sc of the broadband perovskite cell through additive engineering and interface engineering improving the bandgap matching between the electrical layers and reducing the carrier transport barrier through adjusting the work function or conductivity of layers improve the optical coupling between sub cells and the photocurrent of tandem solar cells by light engineering and conformal deposition technology of perovskite cells. At present many technologes to improve the stability of perovskite solar cells including additive engineering and interface engineering but the problem has not been fundamentally solved. Improving the stability of broadband gap perovskite solar cells to that of crystalline silicon solar cells will become an important challenge to limit its large-scale application. In terms of efficiency the mass production efficiency of perovskite/crystalline silicon tandem solar cells is far lower than the laboratory level. One of the reasons is that it is difficult to achieve low-cost and uniform large area perovskite solar cells deposition. Therefore improving the stability of broadband gap perovskite solar cells and developing low-cost large-area perovskite deposition technology will become extremely critical. Finally we look forward to the next generation of higher efficient low-cost tandem solar cells. We believe that with the increasing demond for higher efficiency photovoltaic devices the triple junction solar cells based on the perovskite/crystalline silicon stack structure will become the future of photovoltaics.