Two neighbouring components of twins are not symmetry of reflection or rotation, but of glide reflection.
2024铝合金中的弥散相Al_(20)Cu_2Mn_3普遍由孪晶组成,通过高分辨像的观察分析,发现其孪晶间的界面不是镜面,而是滑移面;孪晶两部分不是反映(或旋转)对称,而是滑移反映对称,“金刚石”滑移面是(101),滑移矢量(1/4)(a-c),组成孪晶的各晶体组元呈棱柱体形状,各侧棱都平行于[010],棱柱侧面是{010}和{100}。
Numerical study on seismic sliding response of free-standing equipments;
浮放设备地震滑移反应数值模拟研究