perforated hard board

Study on Mechanics Character of Perforation Fiber Board;

穿孔纤维板力学特性研究

The application of pedicled buccal fat pad graft for repairing perforation after palatorrhaphy.;

颊脂垫瓣在腭裂术后穿孔修补术中的临床应用

Laparoscopic repair of acute perforation for gastroduodenal ulcer;

腹腔镜胃十二指肠溃疡修补术治疗急性胃十二指肠溃疡穿孔

Experiment on Piercing of Shell for Large-sized Stainless Steel Tube;

大直径不锈钢管坯的穿孔试验

With a view to establishing the mechanism of center crack during two cross roll piercing, the distribution and development of deformation and stress in tube rounds were studied through the use of FE code MARC/Autoforge.

为了分析二辊斜轧穿孔时圆管坯中心金属的断裂机制 ,确立穿孔变形的工艺实质 ,用MARC/ Autoforge软件研究了圆管坯斜轧时的应力、应变场及其发展。

Used each superior equipment and both solved the key of large-sized stainless steel cold-drawn seamless tube-large-sized stainless tube blank and hot-piercing by Taiyuan I&S Co.

太原钢铁集团公司和成都无缝钢管公司双方利用各自装备优势,通过合作解决了生产大口径不锈钢冷拔无缝钢管的关键——大型不锈钢管坯和热穿孔。

The piercing plug is one of the most important tools used for the seamless steel tube production.

穿孔顶头是无缝钢管生产中最重要的模具之一,文章通过分析穿孔机顶头的失效形式,并从顶头外形、材质、表面氧化等方面探索提高顶头使用寿命的方法。

The microstructure and hardness of piercing plug made of 20CrNi3MoW steel were studied.

对20CrNi3MoW钢穿孔顶头的显微组织和硬度变化进行了研究。

This review focuses on various aspects of piercing plug surface oxide film,including formation,compose,property,effect,transformation in the piercing course and the influence of plug's life.

概述了穿孔顶头表面氧化膜的形成、结构、性质、作用,在穿孔过程中的变化及其对顶头使用寿命的影响。

Using transfer matrix method to analyze microperforated panel absorber s acoustic characteristic;

用传递矩阵法分析微穿孔板的声学特性

The possibility and the significance of replacing fibred absorption materials by fibreless materials,especially by microperforated panels,are discussed.

简要地介绍了吸声材料的基本特点，阐述了无纤维性吸声材料（特别是微穿孔板吸声结构）取代传统的纤维性吸声材料的可能性及其重要意义，较详细地介绍了近年来德国以及我国科研人员在无纤维吸声材料研究上所取得的进展。

A calculating program of microperforated panel construction is worked out in this paper.

文中编制了微穿孔板结构的数值分析程序，通过计算实例，对微穿孔板结构的声学特性进行了探讨。