periodically

定期更新

to make something more modern or up-to-date at regular intervals

定期使某事物更现代化或更新

定期审查

to formally assess something at regular intervals, with the possibility of making changes

定期正式评估某事物，并可能作出更改

定期检查

to examine something at regular intervals to ensure it is correct or safe

定期检查某事物以确保其正确或安全

定期测试

to carry out a test at regular intervals to assess quality or performance

定期进行测试以评估质量或性能

定期监控

to watch and check a situation carefully over a period of time at regular intervals

在一段时间内定期仔细观察和检查情况

定期视察

to look at something carefully at regular intervals

定期仔细查看某物

定期修订

to re-examine and make alterations to something (like a document or plan) at regular intervals

定期重新审查并修改（如文件或计划）

定期续订

to make something like a contract or license valid again at regular intervals

定期使合同或许可证等事物再次生效

定期返回

to come or go back to a place at regular intervals

定期地回到或返回某个地方

周期性中断

to stop the continuous progress of an activity or process from time to time

不时地停止一项活动或过程的连续进行

周期性爆发

to break out suddenly and dramatically from time to time, like a volcano or conflict

不时地突然而剧烈地爆发，如火山或冲突