Promotion Strategies of Family Education Guidance Service in Chinese Community

To carry out family education is related to the vital interests of thousands of families, and it is the top priority of the national livelihood work. It has become an international consensus to provide family education guidance services based on communities to improve the level and quality of family education. However, at present, there are still serious problems in the work of family education guidance services in Chinese communities, such as the absence of a normalized policy guarantee system, the weakening of value consensus by the game of stakeholders, and the prominent contradiction between supply and demand of high-quality resources. To this end, the following promotion strategies are proposed: improving relevant policies and regulations and ensuring the working operation mechanism; guiding residents to participate deeply and balancing the demands of stakeholders; deepening the supply-side reform of resources and promoting the quality development of education

Exciton dissociation in 2D layered metal-halide perovskites

: Layered 2D perovskites are making inroads as materials for photovoltaics and light emitting diodes, but their photophysics is still lively debated. Although their large exciton binding energies should hinder charge separation, significant evidence has been uncovered for an abundance of free carriers among optical excitations. Several explanations have been proposed, like exciton dissociation at grain boundaries or polaron formation, without clarifying yet if excitons form and then dissociate, or if the formation is prevented by competing relaxation processes. Here we address exciton stability in layered Ruddlesden-Popper PEA2PbI4 (PEA stands for phenethylammonium) both in form of thin film and single crystal, by resonant injection of cold excitons, whose dissociation is then probed with femtosecond differential transmission. We show the intrinsic nature of exciton dissociation in 2D layered perovskites, demonstrating that both 2D and 3D perovskites are free carrier semiconductors and their photophysics is described by a unique and universal framework