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The replacement of platinum (Pt) by nonprecious catalysts with superior activity and stability for the oxygen reduction reaction (ORR) remains challenging for fuel cell devices. Herein, we describe a controllable strategy to prepare hollow graphitic carbon spheres with Fe–N-doped mesoporous shells via in situ polymerization and functionalization. The optimized catalyst exhibits very superior ORR activity with a half-wave potential (E1/2) of 0.886 V in 0.1 M KOH, 15 mV more positive than that of commercial Pt/C catalysts. Even in acidic solution, it also shows a competitive 4e− ORR activity compared to Pt/C. Most importantly, it demonstrates much better long-term stability and resistance to methanol crossover than Pt/C in both alkaline and acidic media. The outstanding activity is contributed by the synergy of chemical functions (Fe–Nx-coordinated moieties) and excellent structural properties (hollow large cores (∼91 nm), open mesopores (∼2.1 nm) throughout the shells, and highly graphitic microstructures), ensuring rapid mass-diffusion and electron-transfer kinetics and full accessibility of catalytic sites. [ABSTRACT FROM AUTHOR]

This paper aims to discuss the vitality and endangerment of Lalo, a Lolo-Burmese language spoken in Yunnan province in southwest China. Analysis of the data collected during the survey of the use of the Lalo language in Xiaowan area shows that this minority language is definitely endangered. The comparison of the use of language between Nuosu Yi areas and Lalo Yi areas indicates that the endangerment of the Lalo language is related to interruption of intergenerational mother tongue transmission within families and dwindling use of Lalo in the domains of education, media and work. The following five suggestions are proposed for further discussion on preservation and revitalization of the Lalo language: (1) the Lalo language preservation and revitalization programs could be combined with protection of the intangible heritage in Lalo-speaking areas; (2) the Lalo language needs to be comprehensively documented and systematically researched; (3) language teaching and learning materials as well as resources about Lalo culture should be provided using a newly-developed orthography; (4) multilingualism and cultural diversity should be the principle of language development in Lalo-speaking areas; and (5) the preservation and revitalization of Lalo language could be promoted with appropriate policies and adequate financial support as well as widespread support of all parties concerned, especially the speech communities themselves. [ABSTRACT FROM AUTHOR]