4.15 试计算下列玻璃的结构参数及非桥氧分数。-|||-(1)Na2O·SiO2 ()-|||-(2) _(2)Ocdot CaOcdot (Al)_(2)(O)_(3)cdot Si(O)_(2) ()-|||-(3) _(2)Ocdot dfrac (1)(3)(Al)_(2)(O)_(3)cdot Si(O)_(2) ()-|||-(4) (Na)_(2)Ocdot 10CaOcdot 72Si(O)_(2)(wt)% )