SCI论文背景介绍如何撰写3
One of the distinguishing features of academic writing is that it is informed by what is already known, what work has been done before, and/or what ideas and models have already been developed. Thus, in academic texts, writers frequently make reference to other studies and to the work of other authors. It is important that writers guide their readers through this literature. This section of Academic Phrasebank lists some of the phrases that writers may use for this purpose.
A note on the literature review: It is the purpose of the literature review section of a paper or dissertation to show the reader, in a systematic way, what is already known about the research topic as a whole, and to outline the key ideas and theories that help us to understand this. As well as being systematic, the review should be evaluative and critical of the studies or ideas which are relevant to the current work. For example, you may think a particular study did not investigate some important aspect of the area you are researching, that the author(s) failed to notice a weakness in their methods, or that their conclusion is not well-supported (refer to Being Critical).
A note on referencing style: The way a writer refers to other sources varies somewhat across different disciplines. In some cases, where the individual author is important, the author’s name will be the main subject of the sentence; in other cases, the author’s name may only be mentioned in brackets ( … ) or via a number notation system (e.g. footnotes and endnotes). The ‘author as subject’ style is less common in the empirical disciplines (sciences) and more commonly used in the humanities. Different referencing systems are used in different disciplines. In the majority of the examples given here, the Harvard in-text referencing system has been used.
A note on verb tenses: For general reference to the literature, the present perfect tense (have/has + verb + participle) tends to be used. For reference to specific studies carried out in the past, the simple past tense is most commonly used. This is always the case where a specific date or point in time in the past forms a part of the sentence. When referring to the words or ideas of writers, the present tense is often used if the ideas are still relevant, even if the author is no longer alive. The examples given below reflect these general patterns, but these are by no means rigid.
General descriptions of the relevant literature
Research into X has a long history.
The literature has emphasized the importance of …
Different theories exist in the literature regarding …
More recent attention has focused on the provision of …
There are relatively few historical studies in the area of …
A great deal of previous research into X has focused on …
A large and growing body of literature has investigated …
Much of the current literature on X pays particular attention to …
For many years, this phenomenon was surprisingly neglected by …
There is a large volume of published studies describing the role of …
Over the past decade, most research in X has emphasized the use of …
In recent years, there has been an increasing amount of literature on …
The generalisability of much published research on this issue is problematic.
During the past 30 years, much more information has become available on …
A considerable amount of literature has been published on X. These studies …
The first serious discussions and analyses of X emerged during the 1970s with …
Historically, research investigating the factors associated with X has focused on …
What we know about X is largely based upon empirical studies that investigate how …
Reference to previous research or scholarship: normally more than one author
Several recent studies investigating X have been carried out on …
Surveys such as that conducted by Smith (1988) have shown that …
Traditionally, it has been argued that … (e.g. Smith, 1960; O’Brien, 1972).
Early examples of research into X include … (Smith, 1982; O’Brien, 1984).
Twenty cohort study analyses have examined the relationship between …
Recent evidence suggests that … (Smith, 1996; Jones, 1999; Johnson, 2001).
Several biographies of Brown have been published. Smith (2013) presents …
A number of authors have considered the effects of … (Smith, 2003; Jones, 2004).
Many historians have argued that … (e.g. Jones, 1987; Johnson, 1990; Smith, 1994).
There is a consensus among social scientists that … (e.g. Jones, 1987; Johnson, 1990; …
Recently, in vitro studies have shown that X can … (Patel et al., 1997; Jones et al., 1998).
Data from several sources have identified the increased X and Y associated with obesity.
At least 120 case-control studies worldwide have examined the relationship between …
It has been demonstrated that a high intake of X results in damage to … (Smith, 1998; …).
In recent years, a few authors have begun to … (Smith, 1996; Jones, 1999; Johnson, 2001).
Numerous studies have attempted to explain … (for example, Smith, 1996; Kelly, 1998; …).
Previous research findings into X have been inconsistent and contradictory (Smith, 1996; …).
| To date, Thus far, Up to now, | several studies previous studies a number of studies | have | used … found … reported … shown that… indicated that … linked X with Y. suggested that … demonstrated that … tested the efficacy of … investigated the effects of… begun to examine the use of … confirmed the effectiveness of … used longitudinal data to examine … examined the association between … attempted to evaluate the impact of … revealed a correlation between X and Y. analysed the accuracy and precision of … explored the relationships between X and Y. highlighted factors that are associated with … |
It has been suggested that levels of X are independent of the size of the Y (Smith et al., 1995).
It has conclusively been shown that X and Y increase Z (Smith et al., 1999; Jones, 2001 …).
It has been demonstrated that a high intake of X results in damage to … (Smith, 1998; …).
Reference to current state of knowledge
X is a principal determining factor of Y (Smith, 2005; Jones, 2013).
X is one of the most intense reactions following CHD (Lane, 2003).
There is an unambiguous relationship between X and Y (Rao, 1998).
X is significantly reduced during the first months of … (Smith, 2000; Jones, 2006).
X has been found to oppose the anti-inflammatory actions of Y on Z (Alourfi, 2004).
GM varieties of maize are able to cross-pollinate with non-GM varieties (Smith, 1998; O’Brien, …
A relationship exists between an individual’s working memory and their ability to … (Jones, 2002).
Reference to single investigations in the past: researcher(s) as sentence subject
| Smith (1999) | showed that reducing X to 190oC decreased … (see Figure 2). demonstrated that when the maximum temperature is exceeded … found that as levels of literacy and education of the population rise … |
| Jones et al.(2001) | compared the rate of … labelled these subsets as … measured both components of the … used a survey to assess the various … identified parents of disabled children as … set up a series of virtual experiments using … examined the flow of international students … carried out a number of investigations into the … studied the effects of X on unprotected nerve cells. analysed the data from 72 countries and concluded that … interviewed 250 undergraduate students using semi-structured … performed a similar series of experiments in the 1960s to show that … reviewed the literature from the period and found little evidence for this … conducted a series of trials in which he mixed X with different quantities of … investigated the differential impact of formal and non-formal education on … |
Reference to single investigations or publications in the past: time frame prominent
In 1959, a seminal article was published entitled …
In 1889, Brown performed a bilateral ablation of the …
In 1859, the publication of X had a major impact on …
In 1965, Jones published his major historic survey of …
In 1975, Smith et al. published a paper in which they described …
In 1984, Jones et al. made several amino acid esters of X and evaluated them as …
In 1981, Smith and co-workers demonstrated that X induced in vitro resistance to …
In 1990, Patel et al. demonstrated that replacement of H2O with heavy water led to …
In 1990, Al-Masry et al. reported a new and convenient synthetic procedure to obtain …
Thirty years later, Smith (1974) reported three cases of X which …
In the 1950s, Gunnar Myrdal pointed to some of the ways in which …
Following World War 1, Fleming actively searched for anti-bacterial agents.
Almost 20 years ago, Jones (1985) formulated his X theory, centred around …
Reference to single investigations in the past: investigation prominent
A seminal study in this area is the work of …
One study by Smith (2014) examined the trend in …
A recent study by Smith and Jones (2012) involved …
A recent systematic literature review concluded that …
A longitudinal study of X by Smith (2012) reports that …
Preliminary work on X was undertaken by Abdul Karim (1992).
A key study comparing X and Y is that of Smith (2010), in which …
The first systematic study of X was reported by Patel et al. in 1986.
Detailed examination of X by Smith and Patel (1961) showed that …
Analysis of the genes involved in X was first carried out by Smith et al. (1983).
A significant analysis and discussion on the subject was presented by Smith (1988).
The study of the structural behaviour of X was first carried out by Rao et al. (1986).
A small scale study by Smith (2012) reached different conclusions, finding no increase in …
The study by Jones (1990) offers probably the most comprehensive empirical analysis of …
Smith’s comparative study (2012) found that …
Brown’s (1992) model of X assumes three main …
Smith’s cross-country analysis (2012) showed that …
In an analysis of X, Smith et al. (2012) found …
In a follow-up study, Smith et al. (2009) found that …
In an investigation into X, Smith et al. (2012) found …
In a study conducted by Smith (1978), it was shown that …
In another major study, Zhao (1974) found that just over half of the …
In a study which set out to determine X, Smith (2012) found that …
In a randomised controlled study of X, Smith (2012) reported that …
In a large longitudinal study, Smith et al. (2012) investigated the incidence of X in Y.
In one well-known recent experiment, limits on X were found to be … (Al-Masry, 2013)
Reference to single investigations in the past: research topic as main focus
To determine the effects of X, Zhao et al. (2005) compared …
To better understand the mechanisms of X and its effects, Al-Masry (2013) analysed …
X was originally isolated from Y in a soil sample from … (Wang et al., 1952).
The electronic spectroscopy of X was first studied by Smith and Jones in 1970
X formed the central focus of a study by Smith (2002) in which the author found …
X was first demonstrated experimentally by Pavlov (Smith, 2002). In his seminal study …
The acid-catalyzed condensation reaction between X and Y was first reported by Smith in 1872
The way in which the X gene is regulated was studied extensively by Ho and colleagues (Ho et al. 1995 and 1998).