What is "bingxin"

Xie Wanying (October 5, 1900 – February 28, 1999), better known by her pen name Bingxin or Xie Bingxin, was one of the most prolific Chinese writers of the 20th Century. Many of her works were written for young readers. She was the chairperson of the China Federation of Literary and Art Circles. Her pen name Bingxin (literally "Ice Heart") carries the meaning of a morally pure heart, and is taken from a line in a Tang Dynasty poem by Wang Changling.