论文写作技巧系列 | “Respectively”和数字的用法

很多作者，无论其母语为英语或非英语，都经常会错误地使用“Respectively”一词。

”Respectively”是个副词，意思是“分别地、各自地、依次为”，经常在写论文时用到。

其实在行文时不使用这个词倒可能会更清晰一些，不过，如果在列举两组相对应的单项事物时，使用这个词的确有助于节约篇幅。

我们不妨来看下面这个句子：

“The latencies to withdrawal from a painful stimulus in control and transgenic mice were 3 s and 2 s, respectively”。

在这里，对照组小鼠的缩足反射潜伏期是3秒，而转基因小鼠则是2秒。如果我们描述的对象不是“withdrawal from a painful stimulus”，而是较短的词或词组(如，“average weights”)，就不必使用“respectively”；

“Control mice weighed 20±3 g and transgenic mice weighed 17±2 g”要比“Control mice and transgenic mice weighed 20±3 g and 17±2 g, respectively”好，因为后者多了一个额外的词。

请注意，“respectively”一词仅用来表示两组或两个系列中单项事物之间一对一的关系。

因此，下面这个句子是不正确的，也无从理解：“The latencies to withdrawal from 5 g and 10 g painful stimuli in control and transgenic mice were 3 s and 2 s, respectively”。

• “The proportions of monocytes positive for CD163, CD7 and CD11a were 45%, 63% and 70%, respectively”

  (用“respectively”一词后，读者就能清楚地理解这3个百分比指代的是按相同次序排列的3个标记物)

数字1到100、整十整百这样的概数需要全拼写出来，除非指数值单位，或是在叙述一个数值范围。

“The control group (three males and two females)…”

“Patients were administered 3 mg/kg TNF…”

“There were 5–10 patients in each group”

如果数字以及度量衡或时间单位出现在句首，数字和单位均应完整拼写。或者改写句子，不以数字开头。

16 species of whale have been added to the list of the world`s endangered animals. 【错误】
Sixteen species of whale have been added to the list of the world`s endangered animals. 【正确】

如果数字是英文拼写，其单位也要用拼写。

15 mL of buffer was added to the solution. 【错误】

Fifteen milliliters of buffer was added to the solution. 【正确】

“Thirty-three sections were cut from each block using a cryostat”

“Ten microliters of drug was administered to each patient”

“Drug (10 μl) was administered to each patient”

如果句首的数字超过100，为了表达清晰，最好改写这句话。

Three hundred and sixty-seven participants took part in the study. 【错误】

A total of 367 participants took part in the study. 【正确】

数字和单位之间应有一个空格 (百分号 %除外)

20 mg, 40 mL, 3 days, 15%

叙述量时用“of”，但是叙述浓度时不要用“of”

mice were given 50 mg of 3-NPA

mice were given 50 mg/kg 3-NPA

大于9999的数字使用千分位逗号

11,000 2,353,000