Units should be written in accordance with China’s legal units of measurement and relevant international standards for quantities and units. Units should be expressed with symbols rather than Chinese characters. Unit symbols should not be used in expressions without numbers; for example, “per day” should not be written as “per d.” A quarter-em space should be left between a number and its unit. Compound units should use negative powers, such as mg?kg-1. Common unit symbols are shown in Table 1.
Table 1 Common Unit Symbols
Units of Measurement
|
Quantity |
Unit name |
Unit symbol |
|
Length |
metre |
m |
|
Length |
centimetre |
cm |
|
Length |
kilometre |
km |
|
Mass |
kilogram |
kg |
|
Time |
second |
s |
|
Amount of substance |
mole |
mol |
|
Celsius temperature |
degree Celsius |
℃ |
|
Solution concentration |
mol/L |
Use mol/L, not M |
|
Solution concentration |
gram/L |
g/L |
|
Rotational speed |
|
Use r/min, not rpm |
|
Enzyme activity unit |
|
U |
|
Time |
second |
s |
|
Time |
minute |
min |
|
Time |
hour |
h |
|
Time |
day |
d |
|
Mass |
tonne |
t |
|
Volume |
litre |
L |
|
Volume |
millilitre |
mL |
|
10^6 |
mega |
M |
|
10^3 |
kilo |
k |
|
10^-2 |
centi |
c |
|
10^-3 |
milli |
m |
|
10^-6 |
micro |
μ |
|
Heat |
calorie |
Cal |