图4. 带褶皱单晶石墨烯单轴拉伸应力$\!$-$\!$-$\!$应变($\sigma$-$\!$-$\varepsilon $)曲线MD计算结果
Fig. 4. MD simulation results of the stress-strain ($\sigma$-$\!$-$\varepsilon $) relationship of monocrystalline graphene without wrinkles