The tense of a verb shows the time of the verb's action. Present tense is action that is occurring now or that is generally true at all times. Past tense is action that occurred before now, and future tense is action that is yet to occur.
Reference: Day, Robert A. 1998. How to Write and Publish a Scientific Paper. Oryx. 275 p.
Day (1998) discusses tense at length:
There is one special convention of writing scientific papers that is very tricky. It has to do with tense, and it is important because its proper usage derives from scientific ethics.
When a scientific paper has been validly published in a primary journal, it thereby becomes knowledge. Therefore, whenever you quote previously published work, ethics require you to treat that work with respect. You do this by using the present tense. It is correct ot say, 'Streptomycin inhibits the growth of M. tuberculosis (13).' Whenever you quote or discuss previously published work, you should use the present tense; you are quoting established knowledge...
Your own present work must be referred to in the past tense. Your work is not presumed to be established knowledge until after it has been published. If you determined that the optimal growth temperature for Streptomyces everycolor was 37°C, you should say, 'S. everycolor grew best at 37°C.'
In the typical paper, you will normally go back and forth between the past and present tenses. Most of the Abstract should be in the past tense, because you are referring to your own present results. Likewise, the Materials and Methods and the Results sections should be in the past tense, as you describe what you did and what you found. On the other hand, much of the Introduction and much of the Discussion should be in the present tense, because these sections often emphasize previously established knowledge.
The principal exception to this rule is in the area of attribution and presentation. It is correct to say, 'Smith (9) showed that streptomycin inhibits S. nocolor.' It is also correct to say 'Table 4 shows that streptomycin inhibited S. everycolor at all pH levels.' Another exception is that the results of calculations and statistical analyses should be in the present tense, even though statements about the object to which they refer are in the past tense; e.g., 'These values are significantly greater than those of the females of the same age, indicating that the males grew more rapidly.' Still another exception is a general statement or known truth. Simply put, you could say 'Water was added and the towels became damp, which proves again that water is wet.' More commonly, you will need to use this kind of tense variation: 'Significant amounts of type IV procollagen were isolated. These results indicate that type IV procollagen is a major constituent of the Schwann cell ECM.'
- 英文学术写作，一般使用serial comma，可能跟大家中学所学不同。例如：Anthropogenic emissions from power generation, industries, transportation, residential activities, and agriculture were taken from the MEIC inventory.
- 再举个例子：anthropogenic dust，其实也就两个字，写出来一看就懂，但是写成 AD 就很难看懂。除非你的文章就是在讲anthropogenic dust，而且会提到很多很多次，建议不要用缩写。
- 不要跟常用缩写冲突。例如大气化学领域 OA 一般指 organic aerosols。如果你用 OA 表示 oligomerized aerosols, 虽然理论上没有什么不可以，但容易造成读者的混淆，所以应该避免。
- 正文第一次提到的时候全部拼写出来，后面用缩写。例如：Secondary organic aerosols (SOA) are the particulate organic masses produced in the atmosphere. Precursors of SOA include the volatile, semi-volatile, and intermediate volatility organic species in the atmosphere.
Other common mistakes
- Troublesome words
- We conducted six sensitivity simulations over Eastern China for the period between September 1 to 30, 2015. 【这是对的】
- We conducted six sensitivity simulations for the period between September 1 to 30, 2015 over Eastern China 【这是错的】
How to get better
- Keep a list of mistakes you often make. Everytime you finish a manuscript, go down the list and check your manuscript.
- Read and analyze science writers you admire. Imitate their style.
Must-read Books on writing
- David Schultz, Eloquent Science
- Strunk & White, Elements of Style
- Bill Bryson, Troublesome Words
- Robert Day, How to Write and Publish A Scientific Paper
- This page was last modified on 11 September 2020, at 02:01.
- This page has been accessed 813 times.