基于分子的键距矩阵和键联矩阵提出一种新的分子拓扑指数Y。

A novel topological index called Y-index was developed based simultaneously on the bond distance and bond adjacent matrices for a molecular.

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高级线性缩放：打开微距，关闭夜景模式，按音量键缩放。

Linear zoom: Macro on, Night off, Press zoom key to change.

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叶轮结构由特殊材料制作的一空心圆柱体，安装在主轴总成上端轴头上，用圆锥套和键联接传递钮距，高速旋转。

The structure of impeller made by special material a hollow cylinder and installed in spindle assembly with cone at the top of the head, axial and key connection from, high-speed transfer button.

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