double doughnut laser是什么意思

用法例句

The double ring and non bonding pre stress tendon technique is the art of state technology in tunnel construction in the world.

双圈环绕无粘结预应力锚索技术是当前世界在隧洞施工中最先进的技术 ,成功地解决了薄覆盖层的地下洞室群密集分布与高水头对洞室承压要求的矛盾 ,最大限度地缩小了开挖洞径 ,减少了洞身衬砌的钢筋安装量与混凝土浇筑量 ,降低了成本。

From the strong embeddings of some graphs,a small circuit double cover can be obtained.

其中部分图类的强最大亏格嵌入提供该图的一个少双圈覆盖。

Dynamic chromatic number of unicyclic graphs and bicyclic graphs;

单圈图和双圈图的动态色数

Bicyclic graphs are connected graphs in which the number of edges equals the number of vertices plus one.

边数等于点数加1的连通图称为双圈图。

Let G(n)be the set of all the simple connective bicyclic graphs with n vertices.

记G(n)为所有n阶连通简单双圈图所构成的集合。