在国内高校或者研究所就读的绝大多数工科研究生都需要在毕业之前发表一篇或者多篇英文论文。英文论文一般包括Tittle、Abstract、Keywords、Introduction、Experimental section、Results and discussion和Conclusion这几个部分。其中Introduction是一篇论文中必不可少重要组成部分，一般会放在一篇论文中正文内容的最前面，仅次于Abstract和Keywords之后。Abstract和Keywords的重要性大家应该都知道，紧接其后的Introduction重要性也可想而知。我们必须通过Introduction来让读者明白这个篇论文工作的研究背景、研究现状、目前存在的问题、这篇工作将要解决什么问题、通过什么方法去解决问题和最终达到的效果。Introduction不是简单的抄袭和模仿，而是要完全围绕这篇论文的创新点去展开讲述，要能让读者通过阅读这一部分就能明白你研究工作的真正意义。
也可采用三部分分段介绍的模式，第一部分先交代研究背景和现状；第二部分写在你所研究领域目前存在的问题和你将要解决的问题；第三部分再写你采用了什么方法和手段解决这个问题并达到了什么样的效果。
以此篇文章为例，第一部分主要会写相关领域的一些大的背景及具体的现状：引出大的背景，概述该研究领域被研究的原因和实际意义，然后引出本文小背景，具体讲一些你所研究小领域的研究意义、目的以及目前存在的问题。
大背景Heat-resistant steel 53Cr21Mn9Ni4N (21-4N steel) has been widely used for engine exhaust valves because it has excellent strength and toughness at high temperatures, as well as strong corrosion resistance in extreme working environments. In the past decades, 21-4N steel has attracted the attentions of scientists and engineers.
小背景Carbide is one of the most important microstructural features of 21-4N steel. Mechanical properties and behaviours of 21-4N steels at high temperatures strongly depend on the type, shape, size, amount and distribution of carbides. Carbide is formed in the solidification process and is composed by three chemical elements: Cr, Fe and Mn in 21-4N steel. Furthermore, the dissolution of carbides in solution treatment enriches the matrix with alloying elements, which results in an exceptional heat resistance and the capability of secondary hardening by aging precipitates. Undissolved carbides after aging treatment remain in 21-4N steels which lead to the wear resistance. However, mechanical properties will be affected a lot, if the size of them is too large or they have inhomogeneous distribution .
需要注意的是：
（1）研究背景这段的逻辑关系一定要层层递进，先说大的背景，然后引出小的背景。自然切入主题，不要生搬硬套，不要直接说出来显得很突兀。
（2）Introduction部分一定要逻辑清楚，直白描述，不用过度引申说一些和题目不相关的事情，造成引言部分过于冗长，有凑字数的嫌疑。即使后面的实验内容很精彩，引言内容不行也不是一篇合格的文章。
第二部分主要会写一些从小背景过渡到研究相关的引用，其中包括存在的问题及已经报道过的解决方法，对该领域研究问题相关的参考文献的陈列。
需要注意的是！这块一定不是文献的堆砌，而是综述相关研究进展。否则外审可能会说“Introduction部分的文献部分和题目不相关，更多的是文献的堆积。”之类的。
Therefore, it is necessary to control size, shape and distribution of carbides of as-cast and hot-rolled steel, specially the size. A minor amount of Mg in the stainless steels and superalloys significantly refines the carbides in the literature. For example, Gong et al. added Mg(0.01– 0.015wt-%) to the steel Cr14Mo4 and found that a trace amount of Mg can refine and disperse carbides by presenting in the matrix and grain boundary. Ge et al. studied the effects of segregation of Mg (0.024–0.1wt-%,) on high carbon (18wt-% Cr) as-cast steel and found that a minor amount of Mg refines the primary carbide (Cr0.51Fe0.49)7C3, and improves significantly impact toughness of the alloy. Li et al. reported that a trace amount of Mg(0.001wt-%) strengthens carbide segregation and reduces their size in die steel H13. Bor et al. chosen Mar-M247 to study the influence of Mg(0.002–0.008wt-%) microaddition on carbide characteristics and concluded that a trace amount of Mg can change carbide morphology and refine the size of carbides significantly.
这里还需要注意一下的是：准确引用参考文献。要重视参考文献的引用，不要随意引用，不要过量引用，也不要缺引和漏引。
参考文献一般引用高水平，有代表性的学术文献，引用原始文献，引用最新发表的重要文献，少引或者不引综述性的文章，特别是避免引用很长的综述（因为读者不会去看)，不要在不相关的地方自引。
这里的每篇文章尽量用一句话进行简单的概括，与题目不相关的研究结果可以省略不写，尽可能做到句句点题。
第三部分主要概括描述你这篇论文工作中采用策略、方法及结果，阐明你的研究工作的重点和优势。
其中要写明大部分人的研究方法是什么，有什么样的缺点，而你在这方面的研究中采用的新手段和理念（你的亮点）。最后，总结你的工作取得什么样的成就，存在着什么样的师实际意义。
加粗的为套路句式，可以参考。
As aforementioned, many studies investigated the effect of Mg on carbide particle size and on mechanical properties of stainless steels or superalloys. However, few studies have been carried out to study the effect of morphology changes on the transformation of carbides. Therefore, this study concentrates on morphology changes of carbides and the effect of Mg on the M7C3→M23C6 transformation in the 21-4N steel. First of all, this paper provides theoretical thermodynamical calculation of the 21-4N steel with different contents of Mg on the M7C3→M23C6 transformation. Then, three contents of Mg were added into the liquid steel, the liquid steel casted into ingots (as-cast sample) and the ingots through hot-rolling changed into bars (hot-rolling sample). Finally, the microstructure of 21-4N steel including as-cast and hot-rolling samples is analysed. Results in this study are used to explore the effect of Mg on carbide characteristics and control the carbide particle size in stainless steel.
以下是句型汇总↓↓↓
1. 大背景小背景:
For decades, one of the most popular ideas in ... literature is the idea that ...Recent theoretical developments have revealed that ...
Most of the theories of ... are however focused on explaining ...
2. 发现问题:
There is a further problem with ...
Unfortunately, this approach results in problems related to ...
These constraints make the problem difficult to ...
Most of the research in ... field is aimed at solving ...
3. 文献综述
For example, Gong et al. .... Ge et al. studied the effects of ....
4. 研究意义 :
ln comparison with other techniques, this method has the advantage of ...
The benefit of using the ... is expected to ...
引言部分宁短勿长，刚开始写论文的同学最好把引言部分写得简洁精练，运用简单句通过三部分递进的模式。
好的论文一定要表述清晰明了，段落层层递进，就像一篇小说的前情概要一样，让读者对你的研究领域有一个总览全局的了解，那么才能能够对你论文当中具体研究内容感兴趣并做到充分理解。
浙公网安备33010502006705号