引言的写作技巧

引言的写作技巧内容摘要：

in a ten year study of forest dynamics in two hardwood areas in southeastern Ohio forest. The lack of decline reports for oakhickory vegetation in Ohio may simply be because the forest is essentially healthy. Alternatively, decline symptoms may be present but not reported due to a shortage of studies explicitly designed to evaluate decline in certain forest types. [5] The purpose of this study was to conduct a preliminary forest health study of a representative oakhickory forest of southeastern Ohio. A decline index was employed to categorize present symptoms and predict future dynamics while mortality was used as an indicator of past decline and its resultant effects on present forest dynamics. 第二层 (第 4 段 )：指出研究的空白。 关于俄亥俄州橡树与山核桃树减少与死亡的研究报告却很少见。 第三层 (第 5 段 )：说明 本研究项目的目的。 为了填补上述空白，本 文对俄亥俄州东南部 地区的橡树与山核桃 树的健康状况进行初 步研究。 可见，引言一般分为三到四个层次。 每个层次都有各自的任务与目的。 而在语言上也有各自的 特点，掌握这些特点会使写作过程化难为易。 下面将对引言各层次的写作特点和技巧分别加以介绍。 如何写引言的开头 引言开头 (即第一层 )最主要目的是告诉读者论文所涉及的研究领域及其意义是什么，研究要解决什么问题，目前状况或水平如何。 也就是说，开头要回答如下问题： ? What is the subject of the research? ? What is the importance of this subject? ? How is the research going at present? ? In what way is it important, interesting, and worth studying? ? What problem does the research solve? 下面列举几段例子，以说明引言开头如何开门见山点明研究主题，回答以上问题。 例 3 Purple loosestrife (紫千曲菜 ) is a wetland plant which invaded North America in the early 1800s. It is well established in the United States and Canada with serious infestations in the Great Lakes and St. Lawrence regions. 研究主题是 purple loosestrife。 这种植物之所以值得研究，是因为它严重侵扰了五大湖区及圣劳伦斯地区。 例 4 Forecast of the tracks of hurricanes (飓风 )have improved steadily over the past three decades, owing to a bination of better observations and much improved numerical models. These improvements, along with advances in warning systems and preparedness for emergencies, have brought about a significant decline in loss of life. 研究主题是 forecast of the tracks of hurricanes(对飓风轨道的预测 )。 这一领域取得了进步，意义是大大减少人员伤亡损失。 例 5 Environmental indicators(环境指数 )attempt to accurately describe environmental conditions and make available scientifically valid information on environmental trends． 研究主题是 environmental indicators。 环境指数的意义是能够精确地描述环境状况，并能够提供关于环境倾向的科学、有效的信息。 例 6 Acoustic problem occur extensively in long spaces. For example, in road or rail tunnels noise pollution is a serious problem, and in underground stations poor speech intelligibility of public address systems can cause misunderstanding of vital instructions during an emergency. 研究主题是 acoustic problem of longs paces(长空间的声学问题 )，例如，公路与铁路隧道上的噪声污染就是一个严重的问题。 地铁站的广播系统语言清晰度差，造成在紧急状态下信息误解，因此，这个问题值得研究解决。 通过分析例 3 到例 6，还可以发现如下特点。 首先，关键词往往出现在第一句话，回答 What is the research area? 这个问题，迅速将主题告诉读者，避免转弯抹角，影响信息传递。 然后简单介绍该研究领域的意义。 第二，引言开头句子的谓语动词或者是一般现在时态，或者是现在完成时态。 这是因为这些动词所描述的是某研究领域的现状，而不是过去的情况。 引言的开头常用句型还有： 句型 1：研究主题 +谓语动词 be? ． 例 7 a． Fuel cell(燃料电池 )is a technology for the clean and efficient conversion from chemical energy in fossil fuels to electricity． b. Spot welding (点焊 ) is the most widely used joining method in the automobile manufacturing industry. c. Accurate prediction of springback (回弹预测 ) for sheet metal forming process is vital to the design of tools used in automotive sheet stamping operations. 句型 2: 研究主题 + has bee ? a. Semiconductor based industry (基于半导体的工业 )has be e the largest industry for the USA and it has influenced every other industry and every aspect of human life. b. The battery technology has bee increasingly popular in automotive industry. c. Forest decline has bee a favorite topic for environmental studies. a. Synthetic polymers (聚合物 ) are widely used in contact with biological systems in applications such as medicine, biotechnology, food processing and natural water environment. b. Air pollution has been extensively studied in recent years. c. The causes of glaua have been widely investigated recently. d. The importance of safe driving is now well established. 句型 4: Recently, there has been growing interest in / concern about + 研究主题 例 10 a. Recently, there has been growing concern about wastewater biosolid, the residual anic matter produced during waste water treatment. b. In the 1990s there has been growing interest in the development of electric vehicles in response to the public demand for cleaner air. 句型 5: Recently there have / has been extensive / increasing /numerous publications / literature / reporting on + 研究领域 例 11 a. There have been numerous publications over the last ten years on the need for nursing education to keep pace with the increase in knowledge of biological science. b. There has been increasing reporting about forest decline in North America. 句型 6: Researchers have bee increasingly interested in +研究领域 或 :Researchers have recently focused their attention on +研究领域 Researchers are recently paying more attention to + 研究领域 例 12 a. Researchers have bee more interested in environmental indicators. b. Researchers are paying more attention to high pressure injection (高压喷射 ). 如何写文献综述 文献综述是学术论文的重要组成部分，是作者对他人在某研究领域所做的工作和研究成果的总结与评述，包括他人有代表性的观点或理论、发明发现、解决问题的方法等。