Demand for Meteorological Services in Smart Agriculture and Countermeasures

According to the current situation of modern meteorological services and smart agriculture in Tongliao City,the demand for meteorological services in smart agriculture was analyzed,including accurate meteorological services,point-to-point meteorological services,improved agro-meteorological disaster prevention system,and a comprehensive platform for agricultural services.Besides,some countermeasures to strengthen meteorological services for smart agriculture were proposed,such as promoting the construction of agro-meteorological big data,jointly carrying out the work of meteorological information into villages and households,promoting the construction of modern agricultural meteorological service demonstration areas,and advancing weather modification capacity construction.

Origins of the long-range exciton diffusion in perovskite nanocrystal films: photon recycling vs exciton hopping

The outstanding optoelectronic performance of lead halide perovskites lies in their exceptional carrier diffusion properties.As the perovskite material dimensionality is reduced to exploit the quantum confinement effects,the disruption to the perovskite lattice,often with insulating organic ligands,raises new questions on the charge diffusion properties.Herein,we report direct imaging of>1μm exciton diffusion lengths in CH3NH3PbBr3 perovskite nanocrystal(PNC)films.Surprisingly,the resulting exciton mobilities in these PNC films can reach 10±2cm^(2)V^(-1) s^(-1),,which is counterintuitively several times higher than the carrier mobility in 3D perovskite films.We show that this ultralong exciton diffusion originates from both efficient inter-NC exciton hopping(via Forster energy transfer)and the photon recycling process with a smaller yet significant contribution.Importantly,our study not only sheds new light on the highly debated origins of the excellent exciton diffusion in PNC films but also highlights the potential of PNCs for optoelearonic applications.

Numerical study on solid–liquid phase change in paraffin as phase change material for battery thermal management

With the large latent heat and low cost, the paraffin has been widely used in battery thermal management(BTM) system to improve the efficiency and cycling life of power battery. The numerical model of paraffin melting in a cavity has been established, and the effects on the solid–liquid phase change process have been investigated for the purpose of enhancing the heat transfer performance of paraffin-based BTM system. The results showed that the location of the heating wall had great effects on the melting process. The paraffin in the cavity melted most quickly when the heating wall located at the bottom. Furthermore, the effects of thermal conductivity and the velocity of the slip wall have been considered. The gradient of liquid fraction increased with the increase in thermal conductivity, and the melting process could be accelerated or delayed by the slip wall with different velocity.