Accoding to experiment , found that trepanning can obtain the holes of little taper , high roundness , using laser drilling of nearby the last energy threshold gained the holes of high quality 最终得出:在工件上打大孔径的孔时,采用旋切打孔的方法可以得到了圆度高、锥度小的孔质量。
The steam flows through two large diameter ducts （ 2000 ） to the condenser . steam enters from this distribution manifold into the finned tubes at the top of the primary condensing bundles 蒸汽通过1个大孔径管道（ 2000 ）分为两个管道（ 1600 ）流入凝汽器。蒸汽通过配汽集管进入一次冷凝管束顶部的翅片管道。
These amorphous carbon tubes are totally different from those graphitized carbon nanotubes obtained through traditional methods . the simple and direct synthesis method is superior to the usual casting method by mesoporous silica materials 相对于利用中孔sio _ 2为模板合成的中孔碳材料，我们的合成方法更简单直接，并且如此大孔径的有序中孔碳材料也是首次报道。
An application of technology of large size upright deep hole pre - split blasting in yunfu pyrite mine is introduced , and some improvement concrete measures in according to these problems existed in the practice are presented in this article 摘要介绍了大孔径垂直深孔预裂爆破技术在云浮硫铁矿临近边玻控制爆破中的应用，并针对实践中存在的一些问题，提出了具体改进措施。
Based on the construction of large diameter pile foundations at deep water riverbed without overburden for the shengmi bridge in nanchang , the construction difficulties and construction control key points involved in the method for bored pile construction with floating gantry are described 摘要通过对南昌生米大桥深水无覆盖层大孔径桩基施工实践，介绍浮式龙门钻孔桩施工方法中的施工难点和控制重点。
