- 周期性 zhōuqīxìng periodicityThe quality or state of being periodic, or recurring at regular intervals or in cycles.
- 周期表 zhōuqībiǎo periodic tablethe periodic table of the chemical elements
- 周期数 zhōuqīshù period numberperiodic number
- 周期系 zhōuqīxì periodic systemthe systematic classification and arrangement of chemical elements according to their atomic numbers and recurring chemical properties
- 周期解 zhōuqījiě periodic solutionperiodic solution (math.)
- 开发周期 kāifāzhōuqī development cyclethe total duration of time required to complete the development process of a product, project, or software
- 生命周期 shēngmìngzhōuqī life cycle
- 细胞周期 xìbāozhōuqī cell cycle
- 元素周期表 yuánsùzhōuqībiǎo periodic tableperiodic table of the elements (chemistry)
- 经济周期 jīngjìzhōuqī economic cycle
- 双周期性 shuāngzhōuqīxìng double periodicity(math.) double periodicity
- 周期函数 zhōuqīhánshù periodic function
