穿孔板

The diverse types of tracheary elements and perforation plates in secondary xylem of A. asiatica show that previous knowledge about the tracheary elements and perforation plates in secondary xylem of A. asiatica is not complete and thus any inferences about the aboriginality and evolution of a taxon made depending on these traits are not reliable.

根据类叶升麻次生木质部中多变的管状分子类型，认为以往积累的有关毛茛科植物管状分子类型及导管穿孔板类型是不全面的，因此以该性状为参考作出的有关某一个类群的原始性和进化性的推论也是不可靠的。

The construction and properties of the absorption curve of microperforated panel absorber are discussed.

引言微穿孔板吸声器是1966年发展，为吸收高温、高湿度下的强噪声而设计的。

Absorption curve of four micro-perforated panel is the best in three different structure. But its performance is close to three layer micro-perforated panel.

优化后的四层微穿孔板结构在整个频率内的吸声系数曲线最为饱满，但是与三层结构相比，吸声性能提高不多。

Theoretical analysis and calculation on the acoustic properties of perforated panel absorber were described herein.

文章对穿孔板背面紧贴吸声薄层时的声学特性进行了理论分析与计算，并与实验结果作出比较。

Using transfer matrix method to analyze microperforated panel absorber s acoustic characteristic;2. 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。

Stony coral, madriporian coral madreporite

n。筛板，穿孔板 madrid

The sound transmission coefficient of normal incidence is presented.

对影响水中双层穿孔板垂直入射声压透声系数的各项因素进行了详细的仿真分析与讨论。

Filter screen should include a perforated stainless steel plate or reticulocyte, aimed at maximizing the open area.

过滤器屏幕上应包括任何一个不锈钢穿孔板或网织，旨在最大限度地开放区。

A few apomorphic character states, such as simple perforation plates, helical thickenings in secondary walls of vessels and septate fibers, can be found in Schisandraceae, which make this family a mosaic with both plesiomorphic and apomorphic character states.

此外，该科木材还具有单穿孔板导管、导管次生壁具螺纹加厚、具分隔纤维等较为特化的性状状态，这种性状进化水平的异等级现象，使五味子科表现出不同进化水平性状的镶嵌组合。

The calculation result of theory is validated by stationary wave tube experiment.

在此基础上，总结了单层和双层微穿孔板结构声阻抗以及吸声系数的计算方法，利用驻波管实验对理论计算结果进行了验证。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。