主动语态是一种更简单直接的写作方式。因而，相对于被动语态，大部分科学期刊都鼓励投稿人更多的使用主动语态 。 主动语态-主语为行动的实施方。 被动语态-主语为行动的接收方。 在撰写科学论文时我们会使用各种各样的时态。下面是一些在不同时态下使用主动语态和被动语态的例子。 现在时-通常在概论，讨论和结论中使用的时态。 Example 1: Active: Vitamin A increases the risk of hair loss. Passive: The risk of hair loss is increased by vitamin A. Example 2: Active: Volatile organic compounds (VOCs) emitted from industries and vehicle exhausts can induce a series of environmental problems, including photochemical smog, broken ozonosphere, and environmental pollution. Passive: A series of environmental problems, including photochemical smog, broken ozonosphere, and environmental pollution, can be induced by volatile organic compounds (VOCs) emitted from industries and vehicle exhausts. 现在时-通常在目标中使用的时态 Example 1: Active: In this study, we present our design of an electric hot water tank. Passive: In this study, a design of an electric hot water tank is presented. Example 2: Active: This study develops an efficient methodology to examine a space–time continuous dataset for urban irrigation water use. Passive: An efficient methodology to examine a space–time continuous dataset for urban irrigation water use is developed in this study. 现在完成时-通常在概论，讨论和总结中使用的时态。 Example 1: Active: Previous studies have used comparative analysis of ORF2 sequences to elucidate phylogenetic relationships among different FCV isolates. Passive: Comparative analysis of ORF2 sequences has been used in previous studies to elucidate phylogenetic relationships among different FCV isolates. Example 2: Active: Only a small number of empirical studies have focused on the patterns and mechanisms behind disease clusters at small spatial scales, especially in wild host–pathogen systems . Passive: The patterns and mechanisms behind disease clusters at small spatial scales, especially in wild host–pathogen systems, have been focused on by only a small number of empirical studies . 过去时：通常用于材料与方法/结果。 Example 1: Active: We determined the presence of larvae by dip netting. Passive: The presence of larvae was determined by dip netting. Example 2: Active: We evaluated the number of haplotypes (h), haplotypes (Hd), and nucleotides (π) using the DnaSP 5.10 program . Passive: The number of haplotypes (h), haplotypes (Hd), and nucleotides (π) was evaluated using the DnaSP 5.10 program . Example 3: Active: We found a strong correlation between above-ground and below-ground biomass accumulation in Platanus occidentalis. Passive: A strong correlation was found between above-ground and below-ground biomass accumulation in Platanus occidentalis. 然而，您应该尽量使论文中的语言容易理解。所以如需必要时也可以适量使用被动语态。 什么时候该用被动语态： 1. 当强调结果（接收方）而不是行动方（执行者）。 The risk of hair loss is increased by vitamin A . 2. 在同一段落中保持统一的主体和重点。 Female pattern hair loss is common but estimates of its prevalence have varied widely. The risk of female pattern hair loss is increased by vitamin A. 3. 如果不希望指明主体。 The procedures were somehow misinterpreted. 4. 当主体不可知或者不重要的时候。 Every year, thousands of people are diagnosed with cancer. 更多参考文献： Sainani K., Elliott C. Harwell D., 2015. Active vs. Passive Voice in Scientific Writing. ACS Webinars. Available at: https://www.acs.org/content/dam/acsorg/events/professional-development/Slides/2015-04-09-active-passive.pdf . Plotnick J. How to Use Active Voice in the Sciences. University College Writing Centre, University of Toronto, Canada. Available at: http://www.writing.utoronto.ca/advice/specific-types-of-writing/active-voice-in-science . The Writer’s Handbook, 2014. Use the active voice. The Writing Centre, University of Wisconsin. Available at: http://writing.wisc.edu/Handbook/CCS_activevoice.html .
无论是中文文章还是英文文章，目前均有英文摘要，要讲好中国故事，就得更好地掌握英文摘要的撰写，尤其要注意时态与语态问题。以下内容给小伙伴们分享下。 1） 在介绍背景资料时，用一般现在时态来叙述不受时间影响的普通事实。 eg. Most alternative fuels for internal combustion engines have low cetane numbers. 若介绍背景资料的句子内容是对某种研究动向的概述，则用现在完成时态。 eg. The use of correlated coefficient of heat transfer from the experimental data has been the universal choice to analyze… 2) 在叙述研究目的、题目及活动时，若文章采用“研究导向”型，则用一般过去时态；若文章采用“论文导向”型，则用一般现在时态。 研究导向， eg. In this study, we examined vertical nutrient mixing in … 论文导向， eg. This paper presents an auto-refrigerating … eg. In this paper, we focus on the stress-induced laser behavior… 3) 在摘要的实验部分的写作中，实验程序或方法通常用一般过去时态。 eg. The measurements were carried out in a high pressure chamber and … 4) 通常也用一个句子同时表达研究目的和研究方法。 eg. Laboratory compaction and triaxial compression tests were performed to assess the … 5) 常用一般过去时态概述主要结果。 eg. The plant’s thermal efficiency increased from 17.6% to… 6) 用一般现在时态，推测动词或 may, could 情态动词来叙述推论、结论。 eg. The result can be expected to be of great technical interest as basic data for the … 语态：摘要中语态规则与论文正文中语态的使用规则相同。目前，多使用主动语态，这样使表达更强有力、更直接、更简洁。
几乎所有的人都会为时态“犯愁”。我自己也常常纠结，尽管我在博客中说得头头是道。 科学网版： 科技写作时态(Past tense? Present tense?) http://blog.sciencenet.cn/blog-306792-657146.html 浙大版： 英文科技论文时态运用（双语解读,英文示例） https://mp.weixin.qq.com/s/LMYaAAmg3aHflddx3wxWog ［科技英语写作基础（系列）：大纲（1） http://blog.sciencenet.cn/home.php?mod=spaceuid=306792do=blogid=1146690 科技英语写作基础（系列）：大纲（2） http://blog.sciencenet.cn/home.php?mod=spaceuid=306792do=blogid=1146716 ］ 1. 语态 2. 常用时态 3. 一些标点符号（参考 The Elements of Style ） 4. 常用句型（主语谓语的“一致性”，参考 The Elements of Style ） 5. 段落（参考 The Elements of Style ） 6. 修改、修改、再修改（简洁为上／逻辑性／一致性） 请大家多提意见。
英语谓语动词时态共有16种，在英文科技论文中用得较为频繁的主要有三种：即一般现在时、一般过去时和将来时。正确地使用动词时态是科研写作的基本功，我们在撰写英文论文时，如不能正确选用时态，常常会改变文章所要表达的意思，从而影响评审专家与读者的理解。 一篇典型的科技论文有一个基本的框架结构：Abstract (综述科研背景，提出研究的问题和假设(hypothesis))，Materials and Methods (描述自己的研究方法)，Results (分析所得的研究结果)，Discussion (深入讨论研究结果的意义并简要指出将来的研究方向)。我们现根据这个论文框架，就一些规律性问题做些探讨，希望对大家有所帮助。 首先应该把握以下三个基本要点： 1、一般现在时：主要用于不受时间限制的客观存在事实的描述，或发生或存在于写论文之时的感觉、状态、关系等的描述或致谢的表述等。值得注意的是，出于尊重，凡是他人已经发表的研究成果作为previously established knowledge，在引述时普遍都用一般现在时。 2、一般过去时：用于写论文中作者自己所做工作的描述。例如描述自己的材料、方法和结果。 3、 一般将来时：用于撰写论文之后发生的动作或存在的状态。例如提出下一步的研究方向。 摘要（ Abstract ）： 摘要反映我们自己的研究结果，一般 采用过去时 。 概述（ Introduction ）： （ 1 ）概述中的研究背景通常会引用相关学科中广为接受的原理或事实，以及你所做研究的重要性，这些通常采用现在时。 例如：Genomics provides crucial information for rational drug design. （ 2 ）在概述中也可能引用与你从事项目相关的一些研究结果，为表达你对该研究结果仍坚信其正确性及相关性，即使已经是很久以前的研究结果，可使用现在时。 例如：Many of the lakes and wetlands in the region are located in craters or valleys blocked by early Pliocene lava flows (Ollier Joyce, 1964). Garcia (1993) suggested that under certain conditions, an individual’s deposit income is the same as the income from purchased national debt, thus changes in the amount of bank loans and deposits caused by changes in the amount of reserves will eventually affect the bond price. 需要注意的是如果引用的是一些已经过时或失效的科研结果，动词要使用过去时。 例如：Nineteenth-century physicians held that women got migraines because they were the weaker sex, but current research shows that the causes of migraine are unrelated to gender. （注意这里从过去时态过渡到现在时态） 材料与方法（ Materials and Methods ）： 对写论文之前自己所做工作的描述，通常 采用一般过去时。 例如： （例 1） Total phosphorous (TP) and total nitrogen (TN) were measured in the laboratory using standard procedures. （例2） The standard protocol was followed for the preparation of the media from stock solutions. 结果（ Results ）： 对自己得出的研究结果，采用过去时进行详细的阐述。 例如：（例1）Overall, more than 70% of the insects collected were non-phytophagous. （例 2） Following activation of NT oocytes with strontium, the cell cycle resumed in both groups. 描述图表内容通常采用现在时。 例如： （例 1） Figure 1 displays the comparative variation in the morphology of donor chromatin in both age groups of oocytes. （例 2） Table 1 below shows the stream flows calculated for each stream using Equation 1. 图1和表1表达的论文写作时的状态，所以要用现在时。 讨论（ Discussion ） ： 采用现在时表达研究结果的意义。 例如：Removal of vegetation for agricultural purposes appears to negatively affect the water quality of streams. 采用过去时总结研究结果，并采用现在时对研究结果进行讨论与解释。 例如：（例1）Weight increased as the nutritional value of feed increased. These results suggest that feeds higher in nutritional value contribute to greater weight gain in livestock. （注意这里用过去时描述了实验发现，但在讨论这个发现的意义时用的是现在时。） （例2）Leaf carbon and phenolic content did not differ across sites, indicating that the response of secondary plant chemicals such as phenolics to water is complex. （这句的描述几乎没有假设的意思，表示作者坚信其研究结果和结论的正确性及相关性） 结论（ Conclusion ）： 可用多种时态， 使用过去时强调过去的研究成果，并可采用现在时或将来时表达未来的研究方向或研究前景。 例如：Although the study found evidence of tillage and irrigation within the study area, from the data collected it was not possible to determine if the effects of agriculture upstream cause (or caused ) higher levels of total nitrogen downstream. Further studies are therefore necessary to determine the effects of agriculture on the health of Stringybark Creek. （本文转载自LetPub中文官方网站： http://www.letpub.com.cn/index.php?page=sci_writing_2 ）
英语谓语动词时态共有16种，在英文科技论文中用得较为频繁的主要有三种：即一般现在时、一般过去时和将来时。正确地使用动词时态是科研写作的基本功，我们在撰写英文论文时，如不能正确选用时态，常常会改变文章所要表达的意思，从而影响评审专家与读者的理解。 一篇典型的科技论文有一个基本的框架结构：Abstract (综述科研背景，提出研究的问题和假设(hypothesis))，Materials and Methods (描述自己的研究方法)，Results (分析所得的研究结果)，Discussion (深入讨论研究结果的意义并简要指出将来的研究方向)。我们现根据这个论文框架，就一些规律性问题做些探讨，希望对大家有所帮助。 首先应该把握以下三个基本要点： 1、一般现在时：主要用于不受时间限制的客观存在事实的描述，或发生或存在于写论文之时的感觉、状态、关系等的描述或致谢的表述等。值得注意的是，出于尊重，凡是他人已经发表的研究成果作为previously established knowledge，在引述时普遍都用一般现在时。 2、一般过去时：用于写论文中作者自己所做工作的描述。例如描述自己的材料、方法和结果。 3、 一般将来时：用于撰写论文之后发生的动作或存在的状态。例如提出下一步的研究方向。 摘要（ Abstract ）： 摘要反映我们自己的研究结果，一般 采用过去时 。 概述（ Introduction ）： （ 1 ）概述中的研究背景通常会引用相关学科中广为接受的原理或事实，以及你所做研究的重要性，这些通常采用现在时。 例如：Genomics provides crucial information for rational drug design. （ 2 ）在概述中也可能引用与你从事项目相关的一些研究结果，为表达你对该研究结果仍坚信其正确性及相关性，即使已经是很久以前的研究结果，可使用现在时。 例如：Many of the lakes and wetlands in the region are located in craters or valleys blocked by early Pliocene lava flows (Ollier Joyce, 1964). Garcia (1993) suggested that under certain conditions, an individual’s deposit income is the same as the income from purchased national debt, thus changes in the amount of bank loans and deposits caused by changes in the amount of reserves will eventually affect the bond price. 需要注意的是如果引用的是一些已经过时或失效的科研结果，动词要使用过去时。 例如：Nineteenth-century physicians held that women got migraines because they were the weaker sex, but current research shows that the causes of migraine are unrelated to gender. （注意这里从过去时态过渡到现在时态） 材料与方法（ Materials and Methods ）： 对写论文之前自己所做工作的描述，通常 采用一般过去时。 例如： （例 1） Total phosphorous (TP) and total nitrogen (TN) were measured in the laboratory using standard procedures. （例2） The standard protocol was followed for the preparation of the media from stock solutions. 结果（ Results ）： 对自己得出的研究结果，采用过去时进行详细的阐述。 例如：（例1）Overall, more than 70% of the insects collected were non-phytophagous. （例 2） Following activation of NT oocytes with strontium, the cell cycle resumed in both groups. 描述图表内容通常采用现在时。 例如： （例 1） Figure 1 displays the comparative variation in the morphology of donor chromatin in both age groups of oocytes. （例 2） Table 1 below shows the stream flows calculated for each stream using Equation 1. 图1和表1表达的论文写作时的状态，所以要用现在时。 讨论（ Discussion ） ： 采用现在时表达研究结果的意义。 例如：Removal of vegetation for agricultural purposes appears to negatively affect the water quality of streams. 采用过去时总结研究结果，并采用现在时对研究结果进行讨论与解释。 例如：（例1）Weight increased as the nutritional value of feed increased. These results suggest that feeds higher in nutritional value contribute to greater weight gain in livestock. （注意这里用过去时描述了实验发现，但在讨论这个发现的意义时用的是现在时。） （例2）Leaf carbon and phenolic content did not differ across sites, indicating that the response of secondary plant chemicals such as phenolics to water is complex. （这句的描述几乎没有假设的意思，表示作者坚信其研究结果和结论的正确性及相关性） 结论（ Conclusion ）： 可用多种时态， 使用过去时强调过去的研究成果，并可采用现在时或将来时表达未来的研究方向或研究前景。 例如：Although the study found evidence of tillage and irrigation within the study area, from the data collected it was not possible to determine if the effects of agriculture upstream cause (or caused ) higher levels of total nitrogen downstream. Further studies are therefore necessary to determine the effects of agriculture on the health of Stringybark Creek. 此文同步 刊载于 LetPub SCI论文写作辅导材料 ： http://www.letpub.com.cn/index.php?page=sci_writing_2 LetPub 提供 专业英语润色 、 同行资深专家修改 、 专业SCI翻译 、 发表支持 www.letpub.com.cn
Writing About Your Research: Verb Tense CONSISTENCY OF VERB TENSE helps ensure smooth expression in your writing. The practice of the discipline for which you write typically determines which verb tenses to use in various parts of a scientific document. In general, however, the following guidelines may help you know when to use past and present tense. If you have questions about tense or other writing concerns specific to your discipline, check with your adviser. USE PAST TENSE. . . To describe your methodology and report your results. At the time you are writing your report, thesis, dissertation or article, you have already completed your study, so you should use past tense in your methodology section to record what you did, and in your results section to report what you found. We hypothesized that adults would remember more items than children. We extracted tannins from the leaves by bringing them to a boil in 50% methanol. In experiment 2, response varied. When referring to the work of previous researchers. When citing previous research in your article, use past tense. Whatever a previous researcher said, did or wrote happened at some specific, definite time in the past and is not still being done. Results that were relevant only in the past or to a particular study and have not yet been generally accepted as fact also should be expressed in past tense: Smith (2008) reported that adult respondents in his study remembered 30 percent more than children. (Smith's study was completed in the past and his finding was specific to that particular study.) Previous research showed that children confuse the source of their memories more often than adults (Lindsey et al., 1991). (The research was conducted in the past, but the finding is now a widely accepted fact.) To describe a fact, law or finding that is no longer considered valid and relevant. Nineteenth-century physicians held that women got migraines because they were the weaker sex, but current research shows that the causes of migraine are unrelated to gender. (Note the shift here from past tense to present .) USE PRESENT TENSE. . . To express findings that continue to be true. Use present tense to express general truths or facts or conclusions supported by research results that are unlikely to change - in other words, something that is believed to be always true: Genetic information is encoded in the sequence of nucleotides on DNA. Galileo asserted that the earth revolves the sun.(The asserting took place in the past, but the earth is still revolving around the sun. Note also that no source citation is needed here since it is a widely known and well-accepted fact that Galileo made this assertion.) Sexual dimorphism in body size is common among butterflies (Singer1982).(Note how this statement differs from one in which you refer to the researcher's work in the sentence: Singer (1982) stated that sexual dimorphism in body size is common among butterflies. Here you use past tense to indicate what Singer reported, but present tense to indicate a research result that is unlikely to change.) We chose Vietnam for this study because it has a long coastline. (Use past tense to indicate what you did , but present tense to indicate you assume that the length of Vietnam's coastline is unlikely to change.) We used cornmeal to feed the fingerlings because it provides high nutritional content at a relatively low cost. (Past tense reflects what you did , but present tense indicates that neither the nutritional content nor the cost of corn meal is likely to change.) To refer to the article, thesis or dissertation itself. Use the present tense in reference to the thesis or dissertation itself and what it contains, shows, etc. For example: Table 3 shows that the main cause of weight increase was nutritional value of the feed. (Table 3 will always show this; it is now a fact that is unlikely to change, and will be true whenever anyone reads this sentence, so use present tense.) To discuss your findings and present your conclusions. Also use present tense to discuss your results and their implications. Weight increased as the nutritional value of feed increased. These results suggest that feeds higher in nutritional value contribute to greater weight gain in livestock. (Use past tense to indicate what you found , but use present tense to suggest what the result implies.) Sources: Publication Manual of the American Psychological Association, 5th Ed. The Comprehensive Guide to Writing in the Health Sciences, University of Toronto. 来源： http://cgi.stanford.edu/~dept-ctl/tomprof/posting.php?ID=1009
英语谓语动词时态共有16种，在英文科技论文中用得较为频繁的主要有三种：即一般现在时、一般过去时和将来时。正确地使用动词时态是科研写作的基本功，我们在撰写英文论文时，如不能正确选用时态，常常会改变文章所要表达的意思，从而影响评审专家与读者的理解。 一篇典型的科技论文有一个基本的框架结构：Abstract (综述科研背景，提出研究的问题和假设(hypothesis))，Materials and Methods (描述自己的研究方法)，Results (分析所得的研究结果)，Discussion (深入讨论研究结果的意义并简要指出将来的研究方向)。我们现根据这个论文框架，就一些规律性问题做些探讨，希望对大家有所帮助。 首先应该把握以下三个基本要点： 1、一般现在时：主要用于不受时间限制的客观存在事实的描述，或发生或存在于写论文之时的感觉、状态、关系等的描述或致谢的表述等。值得注意的是，出于尊重，凡是他人已经发表的研究成果作为"previously established knowledge"，在引述时普遍都用一般现在时。 2、一般过去时：用于写论文中作者自己所做工作的描述。例如描述自己的材料、方法和结果。 3、 一般将来时：用于撰写论文之后发生的动作或存在的状态。例如提出下一步的研究方向。 摘要（ Abstract ）： 摘要反映我们自己的研究结果，一般 采用过去时 。 概述（ Introduction ）： （ 1 ）概述中的研究背景通常会引用相关学科中广为接受的原理或事实，以及你所做研究的重要性，这些通常采用现在时。 例如：Genomics provides crucial information for rational drug design. （ 2 ）在概述中也可能引用与你从事项目相关的一些研究结果，为表达你对该研究结果仍坚信其正确性及相关性，即使已经是很久以前的研究结果，可使用现在时。 例如：Many of the lakes and wetlands in the region are located in craters or valleys blocked by early Pliocene lava flows (Ollier Joyce, 1964). Garcia (1993) suggested that under certain conditions, an individual’s deposit income is the same as the income from purchased national debt, thus changes in the amount of bank loans and deposits caused by changes in the amount of reserves will eventually affect the bond price. 需要注意的是如果引用的是一些已经过时或失效的科研结果，动词要使用过去时。 例如：Nineteenth-century physicians held that women got migraines because they were "the weaker sex," but current research shows that the causes of migraine are unrelated to gender. （注意这里从过去时态过渡到现在时态） 材料与方法（ Materials and Methods ）： 对写论文之前自己所做工作的描述，通常 采用一般过去时。 例如： （例 1） Total phosphorous (TP) and total nitrogen (TN) were measured in the laboratory using standard procedures. （例2） The standard protocol was followed for the preparation of the media from stock solutions. 结果（ Results ）： 对自己得出的研究结果，采用过去时进行详细的阐述。 例如：（例1）Overall, more than 70% of the insects collected were non-phytophagous. （例 2） Following activation of NT oocytes with strontium, the cell cycle resumed in both groups. 描述图表内容通常采用现在时。 例如： （例 1） Figure 1 displays the comparative variation in the morphology of donor chromatin in both age groups of oocytes. （例 2） Table 1 below shows the stream flows calculated for each stream using Equation 1. 图1和表1表达的论文写作时的状态，所以要用现在时。 讨论（ Discussion ） ： 采用现在时表达研究结果的意义。 例如：Removal of vegetation for agricultural purposes appears to negatively affect the water quality of streams. 采用过去时总结研究结果，并采用现在时对研究结果进行讨论与解释。 例如：（例1）Weight increased as the nutritional value of feed increased. These results suggest that feeds higher in nutritional value contribute to greater weight gain in livestock. （注意这里用过去时描述了实验发现，但在讨论这个发现的意义时用的是现在时。） （例2）Leaf carbon and phenolic content did not differ across sites, indicating that the response of secondary plant chemicals such as phenolics to water is complex. （这句的描述几乎没有假设的意思，表示作者坚信其研究结果和结论的正确性及相关性） 结论（ Conclusion ）： 可用多种时态， 使用过去时强调过去的研究成果，并可采用现在时或将来时表达未来的研究方向或研究前景。 例如：Although the study found evidence of tillage and irrigation within the study area, from the data collected it was not possible to determine if the effects of agriculture upstream cause (or caused ) higher levels of total nitrogen downstream. Further studies are therefore necessary to determine the effects of agriculture on the health of Stringybark Creek. （转载请注明本文来自LetPub中文官方网站： http://www.letpub.com.cn/index.php?page=sci_writing_2 ）
http://www.letpub.com.cn/index.php?page=sci_writing_2 英语谓语动词时态共有16种，在英文科技论文中用得较为频繁的主要有三种：即一般现在时、一般过去时和将来时。正确地使用动词时态是科研写作的基本功，我们在撰写英文论文时，如不能正确选用时态，常常会改变文章所要表达的意思，从而影响评审专家与读者的理解。 一篇典型的科技论文有一个基本的框架结构：Abstract (综述科研背景，提出研究的问题和假设(hypothesis))，Materials and Methods (描述自己的研究方法)，Results (分析所得的研究结果)，Discussion (深入讨论研究结果的意义并简要指出将来的研究方向)。我们现根据这个论文框架，就一些规律性问题做些探讨，希望对大家有所帮助。 首先应该把握以下三个基本要点： 1、一般现在时：主要用于不受时间限制的客观存在事实的描述，或发生或存在于写论文之时的感觉、状态、关系等的描述或致谢的表述等。值得注意的是，出于尊重，凡是他人已经发表的研究成果作为"previously established knowledge"，在引述时普遍都用一般现在时。 2、一般过去时：用于写论文中作者自己所做工作的描述。例如描述自己的材料、方法和结果。 3、 一般将来时：用于撰写论文之后发生的动作或存在的状态。例如提出下一步的研究方向。 摘要（ Abstract ）： 摘要反映我们自己的研究结果，一般 采用过去时 。 概述（ Introduction ）： （ 1 ）概述中的研究背景通常会引用相关学科中广为接受的原理或事实，以及你所做研究的重要性，这些通常采用现在时。 例如：Genomics provides crucial information for rational drug design. （ 2 ）在概述中也可能引用与你从事项目相关的一些研究结果，为表达你对该研究结果仍坚信其正确性及相关性，即使已经是很久以前的研究结果，可使用现在时。 例如：Many of the lakes and wetlands in the region are located in craters or valleys blocked by early Pliocene lava flows (Ollier Joyce, 1964). Garcia (1993) suggested that under certain conditions, an individual’s deposit income is the same as the income from purchased national debt, thus changes in the amount of bank loans and deposits caused by changes in the amount of reserves will eventually affect the bond price. 需要注意的是如果引用的是一些已经过时或失效的科研结果，动词要使用过去时。 例如：Nineteenth-century physicians held that women got migraines because they were "the weaker sex," but current research shows that the causes of migraine are unrelated to gender. （注意这里从过去时态过渡到现在时态） 材料与方法（ Materials and Methods ）： 对写论文之前自己所做工作的描述，通常 采用一般过去时。 例如： （例 1） Total phosphorous (TP) and total nitrogen (TN) were measured in the laboratory using standard procedures. （例2） The standard protocol was followed for the preparation of the media from stock solutions. 结果（ Results ）： 对自己得出的研究结果，采用过去时进行详细的阐述。 例如：（例1）Overall, more than 70% of the insects collected were non-phytophagous. （例 2） Following activation of NT oocytes with strontium, the cell cycle resumed in both groups. 描述图表内容通常采用现在时。 例如： （例 1） Figure 1 displays the comparative variation in the morphology of donor chromatin in both age groups of oocytes. （例 2） Table 1 below shows the stream flows calculated for each stream using Equation 1. 图1和表1表达的论文写作时的状态，所以要用现在时。 讨论（ Discussion ） ： 采用现在时表达研究结果的意义。 例如：Removal of vegetation for agricultural purposes appears to negatively affect the water quality of streams. 采用过去时总结研究结果，并采用现在时对研究结果进行讨论与解释。 例如：（例1）Weight increased as the nutritional value of feed increased. These results suggest that feedshigher in nutritional value contribute to greater weight gain in livestock. （注意这里用过去时描述了实验发现，但在讨论这个发现的意义时用的是现在时。） （例2）Leaf carbon and phenolic content did not differ across sites, indicating that the response of secondary plant chemicals such as phenolics to water is complex. （这句的描述几乎没有假设的意思，表示作者坚信其研究结果和结论的正确性及相关性） 结论（ Conclusion ）： 可用多种时态， 使用过去时强调过去的研究成果，并可采用现在时或将来时表达未来的研究方向或研究前景。 例如：Although the study found evidence of tillage and irrigation within the study area, from the data collected it was not possible to determine if the effects of agriculture upstream cause (or caused ) higher levels of total nitrogen downstream. Further studies are therefore necessary to determine the effects of agriculture on the health of Stringybark Creek. (function(w, d, g, J) { var e = J.stringify || J.encode; d = d || {}; d = d || function() { w.postMessage(e({'msg': {'g': g, 'm':'s'}}), location.href); } })(window, document, '__huaban', JSON); (function(w, d, g, J) { var e = J.stringify || J.encode; d = d || {}; d = d || function() { w.postMessage(e({'msg': {'g': g, 'm':'s'}}), location.href); } })(window, document, '__huaban', JSON);
英文论文写作时态 笔者注 ： 艾思特科学编修 是台湾一家专门从事为科研人员编修发表论文的机构。 研究生 2.0 是一位在美国读博士的台湾人创建的博客，地址已被天朝的防火墙挡在门外，我会不时的挑选一些有用的文章转载到本博客。 本文的地址为 http://goo.gl/ocNxx ，掌握翻墙技术的朋友可以直接到原博客进行查阅，也可以在 Google Reader 中定阅此人的博客。 这篇文章是 艾思特科学编修 提供给研究生 2.0 读者的信息，主要是关于论文时态的一些注意事项。 论文基本文法概念 对所有的研究者或学者们来说，在论文的不同区块使用正确的时态是一件相当挑战的任务，艾思特科学编修于本期季刊中邀您一同探讨这项重要的课题： 当提到「自己的论文文章本身」 任何时候提及自己的论文本身，包括提及论文中的章节或图表时，皆应使用现在简单式。 当提到「一般事实」 「事实」表示恒常不变之真理。因此当论文中提及恒为事实之事件或现象，应使用现在简单式。 当提到「当前研究现象与成果」 当论文中提及该领域「当前研究现象与成果」，表示过去到现在该领域累积的研究成果，应使用现在完成式， 但不包含提及特定文献，以下会加以说明。 当提到「我们的研究」 我们的研究工作 ( 非指文章本身 ) 是在过去完成的，所以应使用过去式。但切记要与研究方法 (methods) 与研究成果 (results) 区隔，研究成果可视为「事实」， 因此需使用现在式。 当提到「特定作者及其文献」 当提到其他作者的特定某篇文献，这些作者们同样是在过去完成他们的研究工作，因此，过去的研究工作使用过去式 当提到「未来研究方向」 除非我们已有具体的未来研究方向计划，不然请勿使用未来式来描述未来研究的方向，或是可换个方式来表达，如 something has to be done 。 时态练习题解说 以下提供时态练习题的解说，请先完成练习，在阅读以下解说，能帮助您迅速了解撰写论文时应选择何种时态： 1. This aim of this paper (was/ is/ has been/ will be) to identify the factors . . . 本句常出现在摘要中，来概括「本论文」的目的，而非本研究，提到自己本身的文章 (this paper) 时使用现在式最佳，故本题应选 is 。 2. Previous researchers (identify/ identified/ have identified) a number of factors. 本句为一般性的描述当前的研究现象与成果 (previous researchers ，非指特定作者 ) ，应使用现在完成式， 故本题应选 have identified 。 3. We (determine/ determined/ have determined) that the factors . . . 本句表达我们在研究的过程中判定 / 决定某事，这个动作是在过去完成的，应使用过去式，故本题应选 determined 。 4. Pierce (claims/ claimed/ has claimed) that the most significant factors include . . . 本句明确的指向特定的作者 (Pierce) ，因此为过去之研究，应使用过去式，故本题应选 claimed 。 5. It is commonly understood that such factors (will be/ are/ were/ have been) crucial to . . . 本句开头 (commonly understood...) 表明后面陈述的为众人熟知的事实，应使用现在式，故本题应选 are 。 6. Figure 7 (shows/ showed/ has shown) that that these factors (were/ are/ have been/ will be) important under these conditions. 本句提及论文中的图表 (Figure 7) ，当提到我们论文本身或其中的章节及图表，应使用现在简单式，故应选 shows 。 7. Despite these findings, further investigation (is/ was/ will be/ has been) necessary. 论文写作中请避免使用未来式。我们的论文在未来五年内都有被人阅读的机会，所以使用未来式将很难界定时间。因此，使用现在式较为安全，故本题应选 is 。 8. In the following section, we (discussed/ will discuss/ discuss) these implications. 本句提及我们的文章中某一章节 (in the following section) ，应使用现在简单式，故本题应选 discuss 。 9. Recent advances (enabled/ have enabled/ enable/ will enable) further development of these resources. 本句首的 Recent 为关键词，表示自过去某段时间一直到现在的成果，应使用现在完成，故本题应选 have enabled 。 10. In a recent study, Lee et al. (have determined/ determined/ determines) that these factors . . . 虽然本句开头与上一句相似，但后面明确指出某特定文献 (Lee et al.) ，因此选用过去式，故本题应选 determined 。
回答：老友关于动词加“了”还是不加“了”的争论：又见师姐 vs 又见了师姐 汉语语言学界比较共识的是，汉语只有完成体，没有过去时 作者: 立委 (*) 日期: 05/18/2011 04:33:11 时 （tense）和 体 （aspect）是两个不同的语法范畴。因为其反映语言时间概念的角 度不同，实际应用中有些纠缠不清，但作为一个语言整体，还是可以论证两者之间的有无和关系的。 英语有非常规整、独立的时和体，看上去很逻辑。简单说来，就是４个时，４个体，两个态（voice: 主动语态，被动语态），构成32种时（体）态的组合：如，主动态现在完成时态包括主动态（active）、现在时（present）和完成体（perfect），被动态一般过去时态包括被动态（passive）、过去时（past）和一般体（simple）。英语动词的形式３２种，元素周期表那样规整漂亮，尽管实际使用的动词形式只有约20种形式（下列时态表格的左上部分）。用二维图表达这种组合颇一目了然：常常是主动语态一个表，被动语态一个表，好反映三维关系（图表见下）。 Tense/Aspect 1 Simple 2 Perfect 3 Progressive 4 Perfect Progressive 1 Present study, studies have/has studied is/am/are studying have been studying 2 Past studied had studied was/were studying had been studying 3 Modal will/can study will/can have studied will/can be studying * will/can have been studying 4 Past Modal would/could study would/could have studied * would/could be studying * would/could have been studying Table 1 : English verb forms for 16 tenses in active voice Tense/Aspect 1 Simple 2 Perfect 3 Progressive 4 Perfect Progressive 1 Present is/am/are studied have/has been studied is/am/are being studied * have been being studied 2 Past was/were studied had been studied was/were being studied * had been being studied 3 Modal will/can be studied will/can have been studied * will/can be being studied * will/can have been being studied 4 Past Modal would/could be studied would/could have been studied * would/could be being studied * would/could have been being studied Table 2 : English verb forms for 16 tenses in passive voice Note: * represent theoretical forms which are not practically used in the language community due to the forms being too complicated. 现代汉语可以用虚字表示“体”，显性表达动词的某种与时间相关的语法意义（譬如“了”之于完成体）。但汉语与英语不同，原则上虚字可用可不用。英语的动词必须使用一种表达“体”的形式，汉语不搞这个形式主义。换句话说，汉语对于使用不使用表达“体”的虚字没有语法上的强制性，使用与否更多地决定于文体和风格。英语则不然，对于谓语动词，必须要使用上表32种动词形式之一来显性表达“时”、“体”和“语态”。 上表列举的是英语谓语动词（finite verbs）的形式，英语还有一种非谓语动词（non-finite verbs），在句子里不需要语法主语，通常是句子里的连带成分。 非谓语动词，主要是不定式（infinitive）和分词（participle) 两类 (也有语法学家把非谓语动词分为三类四种：不定式，动名词，现在分词，过去分词；考虑到动名词与现在分词同形，本文采用的是二分法：ING form and participle form，后者专指过去分词), 形式上虽然没有“时”（其原因是，非谓语一般是附着在句子谓语上的附加成分，所以它的“时”的语法意义不是独立的，而是由相关的谓语动词决定的。非谓语动词虽然没有“时”的形式，但其对“时”的意义仍有隐性的表达，是从谓语动词 carry 过来的。非谓语动词必须显性表达“体”和“语态”的语法意义，见下表。 Voice/Aspect 1 Simple 2 Perfect 3 Progressive 4 Perfect Progressive 1 Active to study to have studied to be studying to have been studying 2 Passive to be studied to have been studied to be being studied to have been being studied Table 1 : English infinitive verb forms for 8 aspect/voice combinations Voice/Aspect 1 Simple 2 Perfect 3 Progressive 4 Perfect Progressive 1 Active studying having studied studying ( * being studying) * having been studying 2 Passive studied having been studied being studied * having been being studied Table 2 : English participle forms for 8 aspect/voice combinations Note: Since the Active-Progressive participle form ( being studying ) is not really used in the community, the simple ING form ( studying ) in effect has to represent both Simple and Progressive aspect: in a context when it is understood as representing Simple aspect, it is also called gerund; otherwise it is called Present Participle. Note also that the Simple Passive participle form ( studied ) is often called Past Participle or Perfect Participle. 当年立委做中学教师前，从高中开始就特别爱画这类表，给“学生”讲解英语时态的逻辑美（屈指算来35年多了，回头看似乎是冥冥之中注定要做“语言学家”的）。表格中带星的右下形式太过复杂，实际上较少使用（譬如 will have been studying）。尤其是被动语态，其动词形式更复杂了一层，因此其中一多半理论上的繁复形式（譬如 would have been being studied）在语言中几乎绝迹。 但是，一般认为，汉语的虚字表达的语法概念属于 体 的范畴，而汉语没有语法 时 的区分。汉语的体类似于英语的体，分类略有不同，大体说来：完成体（了），经验体（过），进行体（着）。换句话说，英语有不同的语法形式来区分现在完成时（have V-ed）和过去完成时（had V-ed），现在进行时（am/is/are V-ing）和过去进行时(was/were V-ing), 但汉语不做这种区分。 关于“了”字的用法，汉学家写过一车文章。譬如，只是动词后的了 １ （ 看了电影 ）才表达完成体，而句末的了 2 （ 看电影了 ）则表达语气，如果恰好遇到一个不及物动词位于句末，则有歧义，具体表达体还是语气或者两者都沾点儿，需要具体情况具体分析。关于了字的用法，钻牛角尖没大意思。二位的争论听上去太小儿科。 【置顶：立委科学网博客NLP博文一览（定期更新版）】
标签: 时态
