空间选择性缺陷管理制备高性能碳基CsPbI_(3)钙钛矿太阳能电池

Defects formed at the surface,buried interface and grain boundaries(GB)of CsPbI_(3)perovskite films considerably limit photovoltaic performance.Such defects could be passivated effectively by the most prevalent post modification strategy without compromising the photoelectric properties of perovskite films,but it is still a great challenge to make this strategy comprehensive to different defects spatially distributed throughout the films.Herein,a spatially selective defect management(SSDM)strategy is developed to roundly passivate various defects at different locations within the perovskite film by a facile one-step treatment procedure using a piperazine-1,4-diium tetrafluoroborate(PZD(BF_(4))_(2))solution.The small-size PZD^(2+)cations could penetrate into the film interior and even make it all the way to the buried interface of CsPbI_(3)perovskite films,while the BF_(4)^(-)anions,with largely different properties from I^(-)anions,mainly anchor on the film surface.Consequently,virtually all the defects at the surface,buried interface and grain boundaries of CsPbI_(3)perovskite films are effectively healed,leading to significantly improved film quality,enhanced phase stability,optimized energy level alignment and promoted carrier transport.With these films,the fabricated CsPbI_(3)PSCs based on carbon electrode(C-PSCs)achieve an efficiency of18.27%,which is among the highest-reported values for inorganic C-PSCs,and stability of 500 h at 85℃with 65%efficiency maintenance.

Indigenous knowledge as data for modern fishery management:a case study of Dungeness crab in Pacific Canada

Introduction:F isheries management is often data-limited,and conducted at spatial scales that are too large to address the needs of Indigenous peoples,whose cultures depend upon the local availability of marine resources.Outcomes:We combined Indigenous ecological knowledge with simulation modelling to inform modern fishery management.Semi-structured interviews with Indigenous fishers in coastal British Columbia,Canada,uncovered severe declines in the abundance and catches of Dungeness crab(Cancer magister)since the 1990s.We modelled the current probability of"successful"crab harvesting trips-as defined by expectations from past catches by Indigenous fishers-using fishery-independent data from nine sites.These probabilities were very low(<20%)for all sites except one.Discussion:Our study highlights that local depletions,which Indigenous fishers attribute to commercial and recreational fisheries,have been widespread and undetected by federal managers who manage Dungeness crab at regional scales without fishery-independent data.Further,local depletions impacted the ability of Indigenous fishers to access traditional foods.Conclusion:Integrating Indigenous knowledge with scientific research is crucial to inform locally-relevant fisheries management and conservation.

可持续食物供给导向的城市边缘区农林用地规划与空间管控研究

Commercial agricultural production, which has altered the global distribution of farmland, garden plot, and woodland, cuts links between cities and their neighboring production land, as well as links between production land and the environment, affecting the quality of food supply and inducing ecological crisis. Closely related to urban-rural public welfare and regional ecological security, sustainable food supply, which is featured by various types, local production, and short-chain transportation, is an effective way to address the negative impact of commercial agriculture. This paper clarifies the important role of agricultural and forest land in urban fringe areas through analyzing the functional connotation and spatial bases of sustainable food supply, and proposes a planning strategy for systematic land protection and efficient spatial management in accordance with the current situation of food supply and compound demands in urban areas. Specifically, it consists of: identifying the land and the support space with potential for diversified food production;establishing an agriculture and forestry support network system and integrating it into regional landscape ecological network;guiding the low impact utilization of production units by following the natural process and resource characteristics;enhancing land protection efficiency based on supporting links.