英語dissertation代寫-英語dissertation引言怎么寫？英語dissertation引言格式，英語dissertation引言寫作技巧

學(xué)術(shù)dissertation中的引言(Introduction)是對全文內(nèi)容和結(jié)構(gòu)的總體勾畫。引言盡管不像摘要那樣有一定的篇幅限制和相對固定的格式，但在內(nèi)容和結(jié)構(gòu)模式上也有需要遵循的規(guī)律。本章首先介紹這些規(guī)律，然后探討需要掌握的語言技巧。

1 引言的內(nèi)容與結(jié)構(gòu)布局
引言的主要任務(wù)是向讀者勾勒出全文的基本內(nèi)容和輪廓。它可以包括以下五項內(nèi)容中的全部或其中幾項：
1）介紹某研究領(lǐng)域的背景、意義、發(fā)展?fàn)顩r、目前的水平等；
2）對相關(guān)領(lǐng)域的文獻進行回顧和綜述，包括前人的研究成果，已經(jīng)解決的問題，并適當(dāng)加以評價或比較；
3）指出前人尚未解決的問題，留下的技術(shù)空白，也可以提出新問題、解決這些新問題的新方法、新思路，從而引出自己研究課題的動機與意義；
4）說明自己研究課題的目的；
5）概括dissertation的主要內(nèi)容，或勾勒其大體輪廓。
如何合理安排以上這些內(nèi)容，將它們有條有理地給讀者描繪清楚，并非容易之事。經(jīng)驗告訴我們，引言其實是全文最難寫的—部分。這是因為作者對有關(guān)學(xué)科領(lǐng)域的熟悉程度，作者的知識是淵博、還是貧乏，研究的意義何在、價值如何等問題，都在引言的字里行間得以充分體現(xiàn)。
我們可以將引言的內(nèi)容分為三到四個層次來安排(如圖所示)。第一層由研究背景、意義、發(fā)展?fàn)顩r等內(nèi)容組成，其中還包括某一研究領(lǐng)域的文獻綜述；第二層提出目前尚未解決的問題或急需解決的問題，從而引出自己的研究動機與意義；第三層說明自己研究的具體目的與內(nèi)容；最后是引言的結(jié)尾，可以介紹一下dissertation的組成部分。
第一層：1) Introducing the general research area including its background, importance, and present level of development……………2) Reviewing previous research in this area…………………
第二層： Indicating the problem that has not been solved by previous research, raising a relevant question ……………………………………………………………………………
第三層：Specifying the purpose of your research……………………………………………
第四層：1) Announcing your major findings ………………………………2) Outlining the contents of your paper ………………………　#p#分頁標(biāo)題#e#
得注意的是，引言中各個層次所占的篇幅可以有很大差別。這一點與摘要大不一樣，摘要中的目的、方法、結(jié)果、結(jié)論四項內(nèi)容各自所占的篇幅大體比例一樣。而在引言中，第一個層次往往占去大部分篇幅。對研究背景和目前的研究狀況進行較為詳細(xì)的介紹。研究目的可能會比較簡短。
引言與摘要還有一點不同的是，摘要中必須把主要研究結(jié)果列出，而在引言中(如果摘要與正文一同登出)結(jié)果則可以省略不寫，這是因為正文中專門有一節(jié)寫結(jié)果(results)，不必在引言中重復(fù)。
比較簡短的dissertation，引言也可以相對比較簡短。為了縮短篇幅，可以用一兩句話簡單介紹一下某研究領(lǐng)域的重要性、意義或需要解決的問題等。接著對文獻進行回顧。然后介紹自己的研究動機、目的和主要內(nèi)容。至于研究方法、研究結(jié)果及dissertation的組成部分則可以完全省略，如所示。
第一層: Introducing the importance of the research area and reviewing previous Research…………………
第二層: Indicating the problem that has not been solved by previous research, raising a relevant question …………………………………………
第三層: Specifying the purpose of your research………………………
可見，引言一般分為三到四個層次。每個層次都有各自的任務(wù)與目的。而在語言上也有各自的特點，掌握這些特點會使寫作過程化難為易。下面將對引言各層次的寫作特點和技巧分別加以介紹。
2 如何寫引言的開頭
引言開頭(即第一層)最主要目的是告訴讀者dissertation所涉及的研究領(lǐng)域及其意義是什么，研究要解決什么問題，目前狀況或水平如何。也就是說，開頭要回答如下問題：
1、 What is the subject of the research?
2、 What is the importance of this subject?
3、 How is the research going at present?
4、 In what way is it important, interesting, and worth studying?
5、 What problem does the research solve?
下面列舉幾段例子，以說明引言開頭如何開門見山點明研究主題，回答以上問題。
例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.
研究主題是purple loosestrife。這種植物之所以值得研究，是因為它嚴(yán)重侵?jǐn)_了五大湖區(qū)及圣勞倫斯地區(qū)。
例Forecast of the tracks of hurricanes (颶風(fēng))have improved steadily over the past three decades, owing to a combination 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.#p#分頁標(biāo)題#e#
研究主題是 forecast of the tracks of hurricanes(對颶風(fēng)軌道的預(yù)測)。這一領(lǐng)域取得了進步，意義是大大減少人員傷亡損失。
例Environmental indicators(環(huán)境指數(shù))attempt to accurately describe environmental conditions and make available scientifically valid information on environmental trends．
研究主題是environmental indicators。環(huán)境指數(shù)的意義是能夠精確地描述環(huán)境狀況，并能夠提供關(guān)于環(huán)境傾向的科學(xué)、有效的信息。
例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.
研究主題是acoustic problem of longs paces(長空間的聲學(xué)問題)，例如，公路與鐵路隧道上的噪聲污染就是一個嚴(yán)重的問題。地鐵站的廣播系統(tǒng)語言清晰度差，造成在緊急狀態(tài)下信息誤解，因此，這個問題值得研究解決。
通過分析這些例子，還可以發(fā)現(xiàn)如下特點。
首先，關(guān)鍵詞往往出現(xiàn)在第一句話，回答What is the research area? 這個問題，迅速將主題告訴讀者，避免轉(zhuǎn)彎抹角，影響信息傳遞。然后簡單介紹該研究領(lǐng)域的意義。
第二，引言開頭句子的謂語動詞或者是一般現(xiàn)在時態(tài)，或者是現(xiàn)在完成時態(tài)。這是因為這些動詞所描述的是某研究領(lǐng)域的現(xiàn)狀，而不是過去的情況。
引言的開頭常用句型有：
句型1：研究主題+謂語動詞be… ．例
a．Fuel cell(燃料電池)is a technology for the clean and efficient conversion from chemical energy in fossil fuels to electricity．
句型2: 研究主題+ has become …
a. Semiconductor based industry (基于半導(dǎo)體的工業(yè))has be come the largest industry for the USA and it has influenced every other industry and every aspect of human life.
b. The battery technology has become increasingly popular in automotive industry.
c. Forest decline has become a favorite topic for environmental studies.
句型3：研究主題 + be 過去分詞（被動語態(tài)）
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 glaucoma 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 + 研究主題
 a. Recently, there has been growing concern about waste-water biosolid, the residual organic 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.#p#分頁標(biāo)題#e#
句型5: Recently there have / has been extensive / increasing /numerous publications / literature / reporting on + 研究領(lǐng)域
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 become increasingly interested in +研究領(lǐng)域 或:Researchers have recently focused their attention on +研究領(lǐng)域；Researchers are recently paying more attention to + 研究領(lǐng)域
a. Researchers have become more interested in environmental indicators.
b. Researchers are paying more attention to high pressure injection (高壓噴射).

3 如何寫文獻綜述
文獻綜述是學(xué)術(shù)dissertation的重要組成部分，是作者對他人在某研究領(lǐng)域所做的工作和研究成果的總結(jié)與評述，包括他人有代表性的觀點或理論、發(fā)明發(fā)現(xiàn)、解決問題的方法等。在援引他人的研究成果時，必須標(biāo)注出處，即這一研究成果由何人在何時何地公開發(fā)表。

3.1文獻出處的標(biāo)注
引用文獻時，不同的學(xué)科或領(lǐng)域可能采用各自約定俗成的體系或格式。在寫dissertation時，應(yīng)該了解自己學(xué)科采用的固定格式。目前最常見的體系有兩種，一種是作者+出版年體系，另一種是順序編碼體系。下面對這兩種體系分別加以介紹。
第一種體系的主要框架模式如下：
模式1：作者(年代)十謂語動詞主動語態(tài)+研究內(nèi)容／成果
a. Hanson et al. (1976) noted that oak mortality and decline were associated with drought and insects throughout a multi-state region of the mid-west.
b. McCarthy (1995) documented 50% hickory mortality, associated with insects, in a ten year study of forest dynamics in two hardwood areas in a southeastern Ohio forest.
c. Also, Fay (1991) found cooperative group projects integrated into science class to be successful experiences for students.
模式2：研究內(nèi)容／成果+謂語動詞被動語態(tài)+(作者年代)
a. Success at this Science Day was found to be linked to parental support (Czemiak 1996).
b. Throughout the eastern United States, large scale compositional changes have been observed in forests dominated by oak and hickory (Christensen 1997, Lorimer 1984, McCarthy et al. 1987, Pallardy et al. 1988).
模式3：It has been十謂語動詞被動語態(tài)+by作者(年代)+that從句 或：It has been+謂語動詞被動語態(tài)+that從句(作者年代)；研究內(nèi)容／成果+謂語動詞被動語態(tài)+by作者(年代)
a. It was found by Czemiak (1996) that success at this Science Day was linked to parental support. 或 It was found that success at this Science Day was linked to parental support (Czemiak 1996).
b. The condition of eastern hardwood species and ecosystems of the United States has been summarized by Weiss and Rizzo (1987) and Millers et al. (1989).#p#分頁標(biāo)題#e#
如果引用的文獻有兩個以上的作者，只標(biāo)明第一作者，后面用拉丁文et al表示，意思是“等人”、“其他人”。如“Hanson et al．”就是如此。
如果在綜述中涉及幾個項目或文獻時，則將這些文獻并列標(biāo)注，必要時用逗號隔開。如 “…Christensen 1997， Lorimerl984，McCarthy et al．1987，Pallardy et al．1988)” 以及 “…Weiss and Rizzo(1987)and Millers et al．(1989)”。
標(biāo)注參考文獻另一種常見體系是按文獻出現(xiàn)的先后順序編號，置于方括號中，標(biāo)在指引部分的右上角。被引用的作者、文獻名、出版時間、地點等列入dissertation后面的參考文獻中。其順序要與正文中標(biāo)注的順序一致。例Forecasts of the tracks of hurricanes have improved steadily over the past three decades [1], owing to a combination of better observations and much-improved numerical models. In contrast to the improvements in track forecasts, there has been comparatively little advance in predictions of intensity [1], in spite of the sophisticated numerical models. The best intensity forecasts today are statistically based[2]. Most of the research literature on hurricane intensity focuses on the pre-storm sea surface temperature and certain properties of the atmospheric environment[3] But it is well known that hurricanes alter the surface temperature of the ocean over which they pass[4] and that a mere 2.5 K decrease in ocean surface temperature near the core of the storm would be enough to shut down energy production entirely[51. Simulations with coupled atmosphere-ocean models[5-7] confirm that interaction with the ocean is a strong negative feedback on storm intensity…
文中標(biāo)注的編號代表參考文獻出現(xiàn)的順序。"[l]"在文中出現(xiàn)兩次，代表這兩處所陳述的內(nèi)容或觀點出自同一篇文獻，即正文后面參考文獻中的第1條。“[5—7]”代表此處陳述的內(nèi)容或觀點涉及到三篇文獻，即參考文獻中第5—7條。
行文中的編號也可以不放在方括號里。如：例The sound attenuation along the length, a significant index in long spaces, has been intensively studied. Based on various assumptions and using various methods, a number of formulae have been given1-5. Another important index, reverberation time, has been seen to be different from that of the diffuse field6.

3.2 文獻綜述中的動詞運用技巧
(1)兩類動詞
我們可以發(fā)現(xiàn)，文獻綜述中常用state， note，observe，discuss，establish，find，present等動詞。這些動詞有兩種特性，一種是描述性動詞，客觀地向讀者介紹他人的工作；另一種是評價性動詞，在一定程度上代表了作者對他人的工作的理解、解釋或態(tài)度。文獻綜述中常用的描述性動詞有：describe，discuss，explain，examine，present，state等。常見的評價性動詞有：affirm，allege，argue，assume，claim，imply，maintain，presume，reveal，suggest等。#p#分頁標(biāo)題#e#
(2)動詞時態(tài)
文獻綜述中最常見的時態(tài)是一般現(xiàn)在時、一般過去時和現(xiàn)在完成時三種時態(tài)。使用不同的動詞時態(tài)會給句子的意義帶來變化，基本原則如下：
原則1：當(dāng)作者引用某人過去某個時間所做過的某一項具體的研究時，用一般過去時。如：例
a. Hanson et al. (1976) noted that oak mortality and decline were associated with drought and insects throughout a multi-state region of the mid-west. …McCarthy (1995) documented 50% hickory mortality, associated with insects, in a ten year study of forest dynamics in two hardwood areas in a southeastern Ohio forest.
b. It was found by Czerniak (1996) that success at this Science Day was linked to parental support. 或 It was found that success at this Science Day was linked to parental support (Czemiak 1996)...
原則2：在概括或總結(jié)某一研究領(lǐng)域里所做過的一些研究時，用現(xiàn)在完成時，如：例
a. The condition of eastern hardwood species and ecosystems of the United States has been summarized by Weiss and Rizzo (1987) and Millers et al. (1989). … Since then, numerous studies have been completed and many regions have established long-term forest surveys to better monitor changes occurring in the eastern forest (Loucks 1992).
b. The sound attenuation along the length, a significant index in long spaces, has been intensively studied. Based on various assumptions and using various methods, a number of formulae have been given [1-5]. Another important index, reverberation time, has been seen to be different from that of the diffuse field [6].
原則3：在談及目前的知識水平、技術(shù)水平或存在的問題時，用一般現(xiàn)在時態(tài)。例
Acoustic problems 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 loss of important travel information and misunderstanding of vital instructions during an emergency. An outstanding feature of long spaces is that classical room acoustic theory is not applicable since the assumption of a diffuse field does not hold with the extreme dimension condition. Consequently, works required for an understanding of the behavior of sound in long spaces and for an acoustic prediction which takes into account the relevant characteristics.
(3)銜接手段
如果綜述中多處需要引用同一個作者或同一篇文章，那么，需要用一些連接手段使上下文銜接，讓意思流暢、連貫，并起到提醒讀者的作用。例
a. The author goes on to say that…
b. The article further states that…　
c. The author also states / argues / believes that …
d. The author concludes that …

4 如何寫研究動機與目的
在介紹了他人在某領(lǐng)域的工作和成果之后，下一步便介紹作者自己的研究動機、目的與內(nèi)容。介紹研究動機可以從兩個角度人手，一是指出前人尚未解決的問題或知識的空白，二是說明解決這一問題，或填補知識空白的重要意義。#p#分頁標(biāo)題#e#
主要句型有：
句型1：用表示否定意義的詞例little，few，no或none of+名詞作主語。如：例
a．Little information／attention／work／research…
b．Few studies／investigations／researchers／attempts…
c．No studies／data／calculations…
d．None　of　these studies／findings／calculations…
注意：
(1)little后面的名詞是不可數(shù)名詞，而few后面是可數(shù)名詞，而且是復(fù)數(shù)形式。
(2)no后面直接用名詞(可數(shù)或不可數(shù)名詞)，表示泛指，“到目前為止還沒有……”的意思，而none of后用指示代詞these，those(或定冠詞the)+名詞，表示“在特定的范圍中還沒有……”的意思。也就是說，在上文所提到過的那些研究中，還沒有解決某一問題，由此來暗示知識的空白部分。
下面舉幾個表示否定意義的例子。
a. Unfortunately, few educational opportunities exit to teach farmers and rural homeowners effective water supply management.
b. There have been few specific reports in the literature of oak and hickory decline.
c. There is, however, little qualitative information regarding purple loosestrife vegetative reproduction.
d. However, there exists little research on science fair projects.
句型2:里表示對照的句型。如:例
a. The research has tended to focus on…, rather than on…
b. These studies have emphasized…, as opposed to…
c. Although considerable research has been devoted to…, rather less attention has been paid to…
d. Although there is much hope that three-dimensional coupled models will lead to better understanding of the factors that control hurricane intensity and to increased reliability of hurricane intensity forecasts, the present generation of models may not have enough horizontal resolution to capture the full intensity of extreme storms.
句型3：提出問題或假設(shè)。如：例
a. However, it remains unclear whether…
b. It would thus be of interest to learn how…
c. If these results could be confirmed, they would provide strong evidence for …
d. These findings suggest that this treatment might not be so effective when applied to…
e. It would seem, therefore, that further investigations are needed in order to…
指出或暗示了知識領(lǐng)域里的空白，或提出了問題或假設(shè)之后，下一步理所當(dāng)然應(yīng)該告訴讀者本研究的目的和內(nèi)容，要解決哪些問題，以填補上述空白，或者證明所提出的假設(shè)。
此部分常見的句型請參見如何寫摘要中的目的部分。這里只略舉幾例。例
a. The aim of the present paper is to give …
b. This paper reports on the results obtained…
c. In this paper we give preliminary results for…
d. The main purpose of the experiment reported here was to…#p#分頁標(biāo)題#e#
e. This study was designed to evaluate…
f. The present work extends the use of the last model by…
g. We now report the interaction between…
h. The primary focus of this paper is on…
i．The aim of this investigation was to test…
j．It　is　the purpose　of the present paper to provide…
從暗示知識的空白到本研究的目的與內(nèi)容一般需要用一些過渡詞，以提示一下讀者。如上面這些例句中，用了this paper，here，the　present　work，now，this investigation，the present paper等詞或詞組。為了引起讀者的注意，這些詞或詞組一般放在句首。例
…The fate of these sections is not clear. In this study we asked the questions: Do shoot sections remain viable and, if so, are they capable of further growth? We also examined the effect of habitat history and section length on survivorship.
如果一項研究、一篇dissertation不止一個目的，應(yīng)該按目的的主次排列順序，并用連接詞或詞組。例
The present work extends the use of the last model to asymmetric, body-vortex cases, thus increasing the range of flow patterns that can be investigated. In addition, an effort is made to improve the numerical procedure to accelerate the convergence of the iterative solution and to get a better rollup of the vortex lines representing the wake.
常見的連接詞還有additionally, in addition to this, besides this, also, not only…but also…, further, furthermore, moreover 等

5 如何寫引言的結(jié)尾
研究目的完全可以作為引言的結(jié)尾。也可以簡單介紹一下文章的結(jié)構(gòu)及每一部分的主要內(nèi)容，從而起到畫龍點睛的作用，使讀者了解文章的輪廓和脈絡(luò)。
至于研究結(jié)果，在引言中完全可以不寫。研究結(jié)果是結(jié)論部分最主要的組成部分。下例是引言的結(jié)尾，介紹文章的結(jié)構(gòu)。例
…Before examining in detail the optimum control strategy for the drivetrain（動力傳動系統(tǒng)）, Section 2 defines the hybrid arrangement under study. A description of the optimization process using an appropriate cost function is then presented in Section 3 followed by a method of translating the resulting control structure into a sub-optimum algorithm capable of being implemented in real time. Using the optimum control structure the effect of component ratings on the vehicle's performance is evaluated in Section 4, while Section 5 discusses the practical implementation of an overall vehicle control algorithm. Finally, in Section 6, an indication of the vehicle's potential for substituting petroleum fuel by electricity is given.
在介紹全文的結(jié)構(gòu)時，要避免使用同一個句型結(jié)構(gòu)，如，Sections l describes…Section2　analyses…Section3　discusses…Section 4 summarizes…這樣，每句話用同樣的詞開頭，句型結(jié)構(gòu)顯得單調(diào)、枯燥乏味。
 
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