AI 中文总结
研究氮掺杂石墨烯机械完整性，通过分子动力学模拟，对比石墨氮簇、空位和吡啶氮簇，发现缺陷构型而非氮含量起决定作用，还明确了共存缺陷相互作用及载荷关系，为容错设计提供依据。
AI 中文摘要
氮掺杂石墨烯的机械可靠性通常归因于其氮含量，然而氮以化学性质不同的构型存在，其各自的机械作用以及与其他缺陷的相互作用仍未得到解决。本文利用单轴拉伸的分子动力学模拟来区分氮化学、缺失原子和缺陷排列对石墨烯强度和断裂的贡献。比较了三个尺寸匹配的缺陷：石墨氮簇、空位和吡啶氮簇，通过两个可控对比分别隔离边缘化学和空位的影响。结果表明，机械完整性由缺陷构型、氮的键合环境以及共存缺陷相对于载荷的排列决定，而非仅由氮含量或缺陷密度决定，为容错设计提供了基础。
英文摘要
The mechanical reliability of nitrogen-doped graphene is often attributed to its nitrogen content, yet nitrogen occurs in chemically distinct configurations whose individual mechanical roles, and whose interactions with other defects, remain unresolved. Here, molecular dynamics simulations of uniaxial tension are used to separate the contributions of nitrogen chemistry, missing atoms, and defect arrangement to the strength and fracture of graphene. Three size-matched defects, a graphitic-nitrogen cluster, a void, and a pyridinic-nitrogen cluster, are compared so that two controlled contrasts isolate the effects of edge chemistry and of the vacancy independently. The graphitic cluster leaves the mechanical properties essentially unchanged (a strength reduction of <1 %), whereas the void degrades the ultimate strength by ~23 % and the pyridinic cluster, which combines the same vacancy with edge nitrogen, is the most damaging (~30 %), failing abruptly from its nitrogen-decorated rim rather than through the damage-tolerant process of the bare void. The mechanical impact of a nitrogen cluster is therefore governed by whether it carries vacancies, not by nitrogen itself. When a nitrogen cluster and a void coexist, their interaction is controlled by orientation relative to the load: in-line defects interact negligibly and fail at the more severe member, whereas side-by-side defects couple through overlapping stress fields and weaken the sheet progressively as they approach, an interaction that persists to separations of ~80 Å. These results establish that the mechanical integrity of nitrogen-modified graphene is determined by the configuration of defects, the bonding environment of nitrogen, and the arrangement of coexisting defects relative to the load, rather than by nitrogen content or defect density alone, thereby providing a basis for defect-tolerant design.
