Climate change adaptation strategies provide a cushion for smallholder farmers,especially in subSaharan Africa against the risks posed by climate hazards such as droughts and floods.However,the decision-making process...Climate change adaptation strategies provide a cushion for smallholder farmers,especially in subSaharan Africa against the risks posed by climate hazards such as droughts and floods.However,the decision-making process in climate adaptation is complex.To better understand the dynamics of the process,we strive to answer this question:what are the potential trade-offs and synergies related to decision-making and implementation of climate adaptation strategies among smallholder farmers in sub-Saharan Africa region?A systematic literature review methodology was used through the Preferred Reporting Items for Systematic Review and Meta-Analysis(PRISMA)statement with the four-stage inclusion/exclusion criteria to identify the literature from selected databases(Scopus and Google Scholar).The climate adaptation strategies are organized into five broad categories(crop management,risk management,soil/land management,water management,and livestock management strategies).Evidence suggests that potential trade-offs may arise concerning added costs,additional labor requirements,and competition among objectives or available resources.The synergies,on the other hand,arise from implementing two or more adaptation strategies concurrently in respect of increased productivity,resilience,yield stability,sustainability,and environmental protection.Trade-offs and synergies may also differ among the various adaptation strategies with minimum/zero tillage,comparatively,presenting more tradeoffs.The development and promotion of low-cost adaptation strategies and complementary climate adaptation options that minimize the trade-offs and maximize the synergies are suggested.Skills and knowledge on proper implementation of climate change adaptation strategies are encouraged,especially at the local farm level.展开更多
Colleges and universities respond to major events and also carry out ideological and political education in pursuit of the common internal goal:to center on the work of fostering virtue in education and buttress the f...Colleges and universities respond to major events and also carry out ideological and political education in pursuit of the common internal goal:to center on the work of fostering virtue in education and buttress the free and all-round development of college students.Major events signify good opportunities and vivid materials for carrying out ideological and political education that is,in turn,the theoretical guidance and ideological guarantee to deal with major events.On the one hand,ideological and political educators in colleges and universities need to follow the law of the process of ideological and political education and formulate coping strategies for major events.On the other hand,they are expected to follow the law of college students’growth,optimize the strategies of ideological and political education,place importance on strengthening the synergy between the two,making joint efforts,and achieving the work objectives and education objectives in the special period.展开更多
The development of high‐performance nonprecious metal catalysts(NPMCs)to supersede Pt‐based catalysts for the oxygen reduction reaction(ORR)in polymer electrolyte membrane fuel cells is highly desirable but remains ...The development of high‐performance nonprecious metal catalysts(NPMCs)to supersede Pt‐based catalysts for the oxygen reduction reaction(ORR)in polymer electrolyte membrane fuel cells is highly desirable but remains challenging.In this paper,we present a pyrolysis strategy for spatial confinement and active‐site fixation using iron phthalocyanine(FePc),phthalocyanine(Pc)and Zn salts as precursors.In the obtained carbon‐based NPMC with a hierarchically porous nanostructure of thin‐layered carbon nanosheets,nearly 100%of the total Fe species are Fe^(Ⅱ)‐N_(4) active sites.In contrast,pyrolyzing FePc alone forms Fe‐based nanoparticles embedded in amorphous carbon with only 5.9%Fe^(Ⅱ)‐N_(4) active sites.Both experimental characterization and density functional theory calculations reveal that spatial confinement through the staggeredπ–πstacking of Pc macrocycles effectively prevents the demetallation of Fe atoms and the formation of Fe‐based nanoparticles via aggregation.Furthermore,Zn‐induced microporous defects allow the fixation of Fe^(Ⅱ)‐N_(4) active sites.The synergistic effect of staggered stacking confinement and microporous defect fixation results in a high density of atomic Fe^(Ⅱ)‐N_(4) active sites that can enhance the ORR.The optimal Fe^(Ⅱ)‐N_(4)‐C electro‐catalyst outperforms a commercial Pt/C catalyst in terms of half‐wave potential,methanol toler‐ance,and long‐term stability in alkaline media.This modulation strategy can greatly advance efforts to develop high‐performance NPMCs.展开更多
文摘Climate change adaptation strategies provide a cushion for smallholder farmers,especially in subSaharan Africa against the risks posed by climate hazards such as droughts and floods.However,the decision-making process in climate adaptation is complex.To better understand the dynamics of the process,we strive to answer this question:what are the potential trade-offs and synergies related to decision-making and implementation of climate adaptation strategies among smallholder farmers in sub-Saharan Africa region?A systematic literature review methodology was used through the Preferred Reporting Items for Systematic Review and Meta-Analysis(PRISMA)statement with the four-stage inclusion/exclusion criteria to identify the literature from selected databases(Scopus and Google Scholar).The climate adaptation strategies are organized into five broad categories(crop management,risk management,soil/land management,water management,and livestock management strategies).Evidence suggests that potential trade-offs may arise concerning added costs,additional labor requirements,and competition among objectives or available resources.The synergies,on the other hand,arise from implementing two or more adaptation strategies concurrently in respect of increased productivity,resilience,yield stability,sustainability,and environmental protection.Trade-offs and synergies may also differ among the various adaptation strategies with minimum/zero tillage,comparatively,presenting more tradeoffs.The development and promotion of low-cost adaptation strategies and complementary climate adaptation options that minimize the trade-offs and maximize the synergies are suggested.Skills and knowledge on proper implementation of climate change adaptation strategies are encouraged,especially at the local farm level.
文摘Colleges and universities respond to major events and also carry out ideological and political education in pursuit of the common internal goal:to center on the work of fostering virtue in education and buttress the free and all-round development of college students.Major events signify good opportunities and vivid materials for carrying out ideological and political education that is,in turn,the theoretical guidance and ideological guarantee to deal with major events.On the one hand,ideological and political educators in colleges and universities need to follow the law of the process of ideological and political education and formulate coping strategies for major events.On the other hand,they are expected to follow the law of college students’growth,optimize the strategies of ideological and political education,place importance on strengthening the synergy between the two,making joint efforts,and achieving the work objectives and education objectives in the special period.
文摘The development of high‐performance nonprecious metal catalysts(NPMCs)to supersede Pt‐based catalysts for the oxygen reduction reaction(ORR)in polymer electrolyte membrane fuel cells is highly desirable but remains challenging.In this paper,we present a pyrolysis strategy for spatial confinement and active‐site fixation using iron phthalocyanine(FePc),phthalocyanine(Pc)and Zn salts as precursors.In the obtained carbon‐based NPMC with a hierarchically porous nanostructure of thin‐layered carbon nanosheets,nearly 100%of the total Fe species are Fe^(Ⅱ)‐N_(4) active sites.In contrast,pyrolyzing FePc alone forms Fe‐based nanoparticles embedded in amorphous carbon with only 5.9%Fe^(Ⅱ)‐N_(4) active sites.Both experimental characterization and density functional theory calculations reveal that spatial confinement through the staggeredπ–πstacking of Pc macrocycles effectively prevents the demetallation of Fe atoms and the formation of Fe‐based nanoparticles via aggregation.Furthermore,Zn‐induced microporous defects allow the fixation of Fe^(Ⅱ)‐N_(4) active sites.The synergistic effect of staggered stacking confinement and microporous defect fixation results in a high density of atomic Fe^(Ⅱ)‐N_(4) active sites that can enhance the ORR.The optimal Fe^(Ⅱ)‐N_(4)‐C electro‐catalyst outperforms a commercial Pt/C catalyst in terms of half‐wave potential,methanol toler‐ance,and long‐term stability in alkaline media.This modulation strategy can greatly advance efforts to develop high‐performance NPMCs.
