Subject + 称之为 + Name/Label
The verb phrase 称之为 (chēng zhī wéi) means 'to call it' or 'to refer to it as,' used when giving something a name or label. The 之 functions as a pronoun meaning 'it,' and 为 means 'as,' so the whole phrase literally means 'call it as.' It is a formal expression commonly found in written Chinese, academic texts, and news reports.
科学家们把这种现象称之为"温室效应"。
kēxuéjiāmen bǎ zhè zhǒng xiànxiàng chēng zhī wéi "wēnshì xiàoyìng."
Scientists call this phenomenon the "greenhouse effect."
人们称之为"世界屋脊"的地方就是西藏。
rénmen chēng zhī wéi "shìjiè wūjǐ" de dìfang jiùshì xīzàng.
The place that people call the "Roof of the World" is Tibet.
这种独特的建筑风格被称之为哥特式。
zhè zhǒng dútè de jiànzhù fēnggé bèi chēng zhī wéi gētèshì.
This unique architectural style is called Gothic.