Maize is a sensitive crop to drought and heat stresses, particularly at the reproductive stages of development. The present study investigated the individual and interactive effects of drought (50% field capacity) and heat (38 °C/30 °C) stresses on morpho-physiological growth, yield, nutrient uptake and oxidative metabolism in two maize hybrids i.e., ‘Xida 889’ and ‘Xida 319’. The stress treatments were applied at tasseling stage for 15 days. Drought, heat and drought + heat stress caused oxidative stress by the over-production of ROS (O 2− , H 2 O 2 , OH − ) and enhanced malondialdehyde contents, which led to reduced photosynthetic components, nutrients uptake and yield attributes. The concurrent occurrence of drought and heat was more severe for maize growth than the single stress. However, both stresses induced the metabolites accumulation and enzymatic and non-enzymatic antioxidants to prevent the oxidative damage. The performance of Xida 899 was more prominent than the Xida 319. The greater tolerance of Xida 889 to heat and drought stresses was attributed to strong antioxidant defense system, higher osmolyte accumulation, and maintenance of photosynthetic pigments and nutrient balance compared with Xida 319.

Three-dimensional metal-halide perovskites have emerged as promising light harvesting materials for converting sunlight to electricity in the last few years. High power conversion efficiency of 23.3% has been demonstrated. However, the main challenge that currently limits the application of the perovskite solar cells is the long-term stability, which has ambient, thermal, and photo stability weaknesses. Recently, the quasi two-dimensional Ruddlesden-Popper perovskites have showed great potential to enhance the stability and achieved an acceptable power conversion efficiency (>13%) compared to the traditional three-dimensional perovskites. The long organic cations in low-dimensional perovskites are more hydrophobic than the typically used short methylammonium cation in three-dimensional perovskites. Here, we summarize recent developments of the Ruddlesden-Popper perovskite solar cells, including Lead-based quasi two-dimensional and Lead-free quasi two-dimensional perovskite structure. The light harvesting performance and charge-carrier dynamics in these perovskite solar cells are reviewed. In addition, critical challenges that limit the performance of Ruddlesden-Popper perovskite solar cells are discussed. Perspectives and future directions are proposed. REVIEW Perovskite Solar CellsEnergy Environ. Mater. 2018, 1, 221-231

No abstract

Sufficient loading of presynthesized quantum dots (QDs) on mesoporous TiO 2 electrodes is the prerequisite for the fabrication of high-performance QD-sensitized solar cells (QDSCs).Here, we provide a general approach for increasing QD loading on mesoporous TiO 2 films by surface engineering. It was found that the zeta potential of presensitized TiO 2 can be effectively adjusted by surfactant treatment, on the basis of which additional QDs are successfully introduced onto photoanodes during secondary deposition. The strategy developed, that is, the secondary deposition incorporating surfactant treatment, makes it possible to load various QDs onto photoanodes regardless of the nature of QDs. In standard AM 1.5G sunlight, a certified efficiency of 10.26% for the QDSC with Cu 2 S/brass counter electrodes was achieved by the secondary deposition of Zn−Cu−In−Se QDs.

No abstract

No abstract

No abstract

No abstract