5专业英语写作.ppt

3、被动语态if 从句和“ when ”从句的压缩。 这两种从句只有在它们的主句和从句的主语都是指一事物的情况下，才能进行压缩。 其他压缩形式 （1）将段落压缩或句子； （2）将句子压缩成名词短语； （3）用技术语表达； Abstract In this paper, fabrication process of superplastic microtube using multi-pass dieless drawing is studied experimentally. Superplastic material used in this experiment is Zn-22%Al alloy tube with outer diameter of 2mm and wall thickness of 0.5mm. A high-frequency induction heating apparatus with air-cooling nozzle is used for the dieless drawing. As a result, after the four-passes dieless drawing, a microtube with outer and inner diameters of 190μm and 91μm, respectively, can be fabricated successfully. It is confirmed that the ratio of inner to outer tube diameters maintains a constant value in multi-pass dieless drawing. In addition, microtubes fabricated by this process is evaluated from microstructure and surface roughness. Consequently, it is found that the manufacture of initial tubes with fine grain and high accuracy is a prime essential to fabricate a superior microtube. Keywords: multi-pass dieless drawing, microtube, superplasticity, Zn-22%Al alloy / ______________________________________________________________ _________________________________________ _________________________________________ ____ ____ 第二节 专业英语科技论文的写作 一、专业英语论文的结构 1. 标题和作者 （Title and Authors） 2. 摘要 （Abstract） 3. 关键词 （Key words） 4. 正文 （Body） 4.1 引言 （Introduction） 4.2 试验方法与过程（包括试验原理、试 验条件与方法、检测手段等）（Experimental procedure） 4.3 试验结果与讨论（Results and Discussion） 4.4 结论 （Conclusion） 5. 附录 （Appendix） 6. 参考文献 （References） 7. 致谢 （Acknowledgement） Investigation on Microstructures of Rapidly Solidified Mg-6wt.%Zn Alloy Prepared by Atomization-twin Rolls Quenching Technology T.Zhou1 ，Z.H.Chen2 (1. College of Material Science and Engineering, Ch