digital object identifier       
noun [ C ]  internet & telecoms specialized (also Digital Object Identifier) uk/ˌdɪdʒ.ɪ.təl ɒb.dʒɪkt aɪˈden.tɪ.faɪ.ər/ us/ˌdɪdʒ.ɪ.t̬əl ɑːb.dʒɪkt aɪˈden.t̬əˌfaɪ.ɚ/ (abbreviation DOI)
 数字对象标识符
a unique series of numbers attached to a piece of digital information such as a website, file, or online article
  A digital object identifier is a permanent identifier given to an electronic document.  数字对象标识符是赋予电子文件的永久性标识符。 
 - More examples
 - In the citation of online journals and similar resources, an address-independent Digital Object Identifier has been supplied where available.
 - The company is committed to enhancing its offering with digital object identifier registration as part of the peer-review process.
 - A DOI (Digital Object Identifier) is a kind of ISBN for internet documents which guarantees that you find the text also if its internet address changes.