Fig. 1. Molecular dynamics model of mono-layer MoS₂: (a) With twin boundaries; (b) without twin boundary. 单层MoS₂的分子动力学模型　(a)含孪晶界; (b)不含孪晶界

Fig. 2. (a) Strain energy E and (b) stress σ, where ε denotes strain. (a)应变能E; (b)应力σ, 其中ε表示应变

Fig. 3. Atomic structures corresponding to the tensile curves: (a) With twin boundary, point A, ε = 27.74%; (b) with twin boundary, point B, ε = 27.79%; (c) without twin boundary, point A, ε = 28.94%; (d) without twin boundary, point B, ε = 29.24%. 与拉伸曲线相对应的原子结构　(a)孪晶界, A点, ε = 27.74%; (b)孪晶界, B点, ε = 27.79%; (c)不含孪晶界, A点, ε = 28.94%; (d)不含孪晶界, B点, ε = 29.24%

Fig. 4. Effects of temperature and the twin lamellar spacing: (a) Effect of temperature on strain energy; (b) effect of temperature on stress; (c) effect of twin lamellar spacing effect on strain energy; (d) effect of twin lamellar spacing effect on stress.温度和孪晶界面间距的影响　(a)不同温度下的应变能; (b)不同温度下的应力; (c)不同孪晶片层间距下的应变能; (d)不同孪晶片层间距下的应力

Fig. 5. Effect of a Mo₃S₂ void on the tensile stress of specimen 孔洞对拉伸应力的影响

Fig. 6. Voided mono-layer MoS₂ without twin boundary: (a) ε = 0; (b) ε = 22.514%; (c) ε = 22.514%, enlarged view; (d) ε = 23.345%, enlarged view. 不含孪晶界的带孔洞的单层MoS₂ 　(a) ε = 0; (b) ε = 22.514%; (c) ε = 22.514%, 放大视图; (d) ε = 23.345%, 放大视图

Fig. 7. Voided mono-layer MoS₂ with twin boundaries: (a) ε = 0; (b) ε = 19.971%; (c) ε = 19.971%, enlarged view; (d) ε = 20.779%, enlarged view. 含孪晶界的带孔洞的单层MoS₂ 　(a) ε = 0; (b) ε = 19.971%; (c) ε = 19.971%, 放大视图; (d) ε = 20.779%, 放大视图

Fig. 8. Distribution of tensile stress in the voided mono-layer MoS₂ sheet with twin boundaries: (a) ε = 14.34%; (b) ε = 16.92%; (c) ε = 18.25%; (d) ε = 20.87%. 带孔洞的含孪晶界模型断裂前后应力分布状态　(a) ε = 14.34%; (b) ε = 16.92%; (c) ε = 18.25%; (d) ε = 20.87%

Fig. 9. Correlation of the fracture strain ε_A and the twin lamellar spacing D. 断裂应变ε_A与孪晶片层间距D的关联

Table 1. Initial in-plane size of model.