What does "self-improvement and virtue" mean?

"Self-improvement" requires that Tsinghua students have the character to strive for excellence and to be courageous.

"Virtuousness" requires Tsinghua students to have the spirit of solidarity, self-discipline and selfless dedication.

The original sentence is from the Book of Changes.

"As the sky moves, a gentleman is unrelenting in his self-improvement; as the earth moves, a gentleman is generous in his virtue".

Expanded:

The Zhouyi, or the Book of Changes, one of the Three Books of Changes (another point of view: that the Book of Changes is the Three Books of Changes, not the Zhouyi), is one of the traditional classics, which is rumored to have been composed of the book by King Ji Chang of the Zhou Dynasty, and includes two parts, namely, the Book of Changes and the Book of Changes. The "Jing" is mainly sixty-four hexagrams and three hundred and eighty-four lines, hexagrams and lines have their own instructions (trigrams, lines), as a divination.

The concepts of yin and yang and taiji were not introduced in the Zhouyi, and it was the Yi Chuan that was influenced by Taoism and the yin and yang school that spoke of yin and yang and taiji. The Chuan contains seven texts*** ten articles explaining the trigrams and lines, collectively known as the Ten Wings, which are said to have been compiled by Confucius.

Spring and Autumn period, the official school began to gradually evolve into a private private school. Yi science before and after the cause, the development of change, a hundred schools of thought, Yi science is followed by the occurrence of differentiation. Since Confucius praised the Yi, "Zhou Yi" was regarded as the sacred text of Confucianism, the first of the six sutras. Outside of the Confucianism, there are two branches of Yijing and the development of the Confucianism Yijing side by side: one for the old forces still exist in the divination of Yijing; the other for the Laozi's Taoism Yijing, Yijing began to be divided into three branches.

The Siku Quanshu General Catalog categorizes the history of Yiology into "two schools and six sects". The two schools, that is, the School of Elephant and Math and the School of Righteousness; the six sects, one for divination, two for praying, three for creation, four for Laozhuang, five for Confucianism, and six for history.

The Zhouyi is the theoretical root of natural philosophy and humanistic practice in traditional Chinese thought and culture, and is the crystallization of the thoughts and wisdom of the ancient Han people, known as "the source of the Great Dao". It is the crystallization of the thinking and wisdom of the ancient Han people, and is known as the "source of the great Tao". It is extremely rich in content, and has had an extremely profound impact on China's politics, economy, culture, and other fields for thousands of years.

Reference: Baidu Encyclopedia: Zhou Yi