如何掌握印刷压力

<正> 一、印刷压力的概念与作用 印刷的过程,从某种意义上讲,是解决油墨与纸张之间矛盾的过程。要将印版上图文处的油墨转移到承印物上,就必须施加一定的力,即所谓的印刷压力。它在印刷中具有重要的作用。 1.保证粗糙的印刷面完全接触 纸张、橡皮布、印版的表面均成粗糙微孔状。对这些粗糙表面,必须在一定的压力作用下,使其受     

有限元计算瞬态动力分析中关于阻尼与初始速度影响的初步讨论

本文主要对在有限元计算的振动瞬态分析中各阻尼系统相互之间关系与这些参数如何影响结构振动特性以及在振动瞬态分析中初始速度对振动过程的影响这二方面问题进行讨论。在分析中虽然只是对悬臂梁进行分析，但其分析结果可用于对叶片振动的瞬态动力分析中。     

一座绿色办公楼——清华大学设计中心楼(伍舜德楼)

2000年9月在悉尼举行的第27届奥运会给世人留下了很多美好的回忆，而对于建筑界来说，更大的触动是悉尼人将这盛大的运动会赋予了“绿色奥运”的理念。这次悉尼奥运场馆是由一家专门从事环保设计的公司负责奥运会一切设施的环保设计，因此有了把碎木屑、稻草压成再生板用作隔墙板、把太阳能蓄电池用在奥林匹克大道路灯的夜间照明、收集雨水用来浇灌花园、甚至把几座垃圾山变成鲜花盛开的公园的种种奇思妙想，悉尼人对“绿色奥运”的理解的确给人很多的启发。当人类终于意识到社会的发展与自然界的发展的地位是同等重要时，一个尊重自然、关…     

轴类零件形位公差的选用

以轴为例，结合零件的使用要求，技术条件，介绍用类比法和计算法选用形位公差的方法。     

聚乙烯醇侧链液晶的结构与液晶性研究

研究了聚乙烯醇侧链液晶主链分子量和液晶基元等结构因素对其液晶性的影响，结果表明随着聚合物的分子量增加，导致复合物清亮点温度下降。但是在液晶主链尚未被液晶基元饱和之前，随着液晶基元相对主链摩尔比的增加，样品形成较为完善的氢键结构。     

聚羧酸类LEX-9高性能减水剂性能分析及应用

介绍了聚羧酸类LEX-9高性能减水剂的性能和在实际应用中的体会。     

Preparation of Laminin-apatite-polymer Composites Using Metastable Calcium Phosphate Solutions

A synthetic polymer with a laminin-apatite composite layer on its surface would be useful as a percutaneous device. The preparation of such a composite was attempted in the present study using poly（ ethylene terephthalate ） （PET） and polyethylene （PE） as the synthetic polymer. PET and PE plates and those pretreated with an oxygen plasma were alternately dipped in calcium and phosphate ion solutions, and then immersed in a metastable calcium phosphate solution supplemented with laminin （ LCP solution ）. The PET and PE plates pretreated with an oxygen plasma formed a uniform and continuous layer of a laminin-apatite composite on their surfaces. In contrast, the PET and PE plates that had not been pretreated with an oxygen plasma did not form a continuous layer of a laminin-apatite composite on their surfaces. The hydrophilic functional groups on the PET and PE surfaces introduced by the plasma treatment were responsible for the successful laminin-apatite coruposite coating.     

Synthesis and Characterization of Poly （L-lactide-co-ε-caprolactone） Copolymers

A series of random and block poly（ L-lactide-co-e-caprolactone ） （ PCLA ） copolymers whh different composition are prepared using stannous octaoate as catalyst.The effects of the amount of initiator on the intrinsic viscosity have been investigated. The structure of the PCLA copolymers is characterized by means of nuclear magnetic resonance（ NMR ）, Fourier transform infrared spectrum （ FTIR ）, differential scanning calorimetry （ DSC ） and X- ray diffraction （ XRD ） methods. It is shown that the synthesis condition and the composition of copolymers obrious influence on the structure of PCLA copolymers. Hydrolytic degradation of the copolymers in a PBS solution of pH 7.4 at 37.0℃ shows that the copolymers of different composhions degrade at different rates.