在一篇文章中寻找出现频率最高的单词，并输出该单词及其出现次数。
文章：“Many models have been developed in the field of natural language processing (NLP). Some of the most famous models are word2vec, GloVe, and BERT. These models have revolutionized the way AI understands and processes human language.”
出现频率最高的单词是 "models"，出现了两次。