on occasion释义：

有时；偶尔

例句：

She had on occasion praised him extravagantly.

她有时曾过分地表扬他。

in occasion释义：

在的场合

例句：

This scheme can achieve the satisfactory static and dynamic response, and can be used in occasion of high quality voltage waveform.

此方案可使逆变电源输出电压波形兼具良好的稳态和暂态特性，可用于逆变电源输出波形质量要求较高的场合。