Li studied in a private school since childhood and received a good family education. He is intelligent and studious, and he can recite the poems he has read at a glance.
At the age of 9, Li found a China ancient mathematical masterpiece "Nine Chapters Arithmetic" on his father's bookshelf, which was very novel and interesting, and he became fascinated with mathematics from then on.
14 years old, Li learned the first six volumes of Euclid's Elements of Geometry, namely Xu Guangqi (1562- 1633) and Matteo Ricci (M.Ricci,1522-1663) in the late Ming Dynasty. Euclid's strict logical system and clear mathematical reasoning are quite different from the traditional mathematical thinking in ancient China, which emphasized practical solutions and calculation skills, and each has its own characteristics and advantages. On the basis of Nine Chapters Arithmetic, Li absorbed the new ideas of Geometry Elements, which made his mathematical attainments deeper and deeper.
A few years later, as a student of a county, Li went to Hangzhou, the provincial capital, to take the provincial examination. Because he "dabbled in exegetics, but he was not as good as arithmetic, so he was deeply involved in arithmetic" (Li Xizhai's Arithmetic Preface), and as a result, the eight-part essay was not well done and fell behind. But he doesn't mind at all. Instead, I took advantage of the opportunity in Hangzhou to collect all kinds of math books, bought back Ye Li's circle-measuring goggles and Dai Zhen's Pythagoras circle, and studied them carefully, which greatly improved my math level.
Wu, a native of Haiyan, wrote in the poem "Reading the Book of Domains, Showing Uncle Li": "Many streams converge into one valley, and elegant words count. There are factions in China and the West, and the diameter of the circle is poor. " "Three series to explore China method, the rest is difficult to understand. The rest are eager to learn, and their minds are poor and single-minded. " Xu Xiang's Notes to Xia Chuan's Poems: "Qiu Yong (Wu) inherited Mr. Siting's family studies, and was especially stubborn and earnest. Uncle Li in Tongli is good at being a teacher in Lanzhou. " It seems that Li once studied mathematics with his teacher.
In his hometown, Li and Jiang, Cui Dehua and other relatives and friends organized the Huyin Society, and often went to Dongshan Villa to sing with different rhymes. At that time, the height of Dongshan Mountain was calculated by using the principle that the corresponding sides of Pythagoras were proportional. Chen Huan, his teacher of Confucian classics, said in The Origin of Teachers and Friends that he "always set a table line when learning the technique of nine numbers, and used the length formula to measure the sun scenery according to the seasonal climate, so it was easy to miss the exam". In Vernacular Chinese, Yu Yue said that he "sat on the top of the mountain at night to measure the latitude of the image". There is still a story in Li's hometown: on his wedding night, he poked his head out of the attic window to see the stars.
1840, the Opium War broke out and imperialist powers invaded China, which inspired Li's thought of saving the country through science. He said, "Wow! Today, European countries are becoming more and more powerful, which is a border issue for China. Pushing the original reason, the machine is fine, and pushing the original machine is fine, which is clear. " "In China, everyone learns to calculate on different days and makes beautiful instruments. In other countries outside Weihai, he was shocked and paid tribute. " Since then, he has been engaged in mathematical research in his hometown.
Around 1845, Li set up a library in Jiaxing to teach students, and was able to meet scholars (mainly mathematicians) in Jiangsu and Zhejiang provinces (1799- 1862), Zhang (1808- 1885) and Zhang. During this period, Li's works on "Pointed Cone Technique" such as Interpretation, Revealing Arrow's Secret and Logarithmic Exploration came out one after another. Later, he wrote Four Yuan Festival and Linde Shu Jie.
185 1 year, Li met the famous mathematician Dai Xu (1805- 1860). Dai Xu said in 1852, "Last year, I was handed over to Uncle Li Jun of Haichang, and ... I was sentenced to correct my unfinished manuscript, and Uncle Ren rewarded Yu Arc. Is it rare to have the help of friends and friends? " (Preface to Dai Xu's Confidentiality Rate) Li and his friends learn from each other academically and learn from each other's strengths. He and mathematicians Luo Shilin (1774- 1853) and Xu Youren (1800- 1860) also "post questions and reply frequently."
In the summer of 1852, Li went to Shanghai Mohai Library to show his mathematical works to foreign missionaries in China, which was appreciated by (A.Wylie, 18 15- 1887) and others. From then on, he began to cooperate with foreigners to translate western scientific works.
The first work translated by Li was the last nine volumes of Euclid's Elements of Geometry. At the same time, he translated twenty volumes of Re-learning with J. Edkins (1823-1905). Later, he also translated Tan Tian (Volume 18), Algebra (Volume 13) and Grading in Differential Calculus (Volume 18) together with Wei (Volume13). The above books were published by Shanghai Mohai Library 1857 to 1859. In addition, he co-translated Naiduan Mathematics with Alexander Wylie and John J. Flair (that is, Newton's Mathematical Principles of Natural Philosophy), but it was not completed and could not be published.
1860, Li was a guest in the shogunate of Jiangsu Governor Xu Youren. After the Taiping Army occupied Suzhou, all his articles, including all kinds of manuscripts, were lost. From then on, he "refused to care about current affairs", avoided Shanghai, immersed himself in mathematical research and wrote a new book. At the same time, he had academic contacts with mathematicians such as Wu Jiashan and Liu Yicheng.
186 1 autumn, Zeng Guofan (181-1872), the leader of the westernization movement and governor of the two rivers, founded Anqing Inner Ordnance Institute in Anhui, and invited the famous chemist Xu Shou (1872). 1862, Li was also hired as a bookstore owner. As soon as he arrived in Anqing, he took out mathematics books such as Geometry Elements destroyed by the war, requested Zeng Guofan to reprint them, and recommended Zhang, Zhang Sigui and others to enter the curtain. They live in the same place, often have academic discussions and actively participate in activities related to science and technology in the new westernization policy.
1In the summer of 864, Zeng Guofan captured Tianjing (now Nanjing), the capital of the Taiping Heavenly Kingdom, and Li and others followed him to Nanjing. He once again proposed to Zeng Guofan to engrave his translated math books into words, which was supported and funded by Zeng Guofan. Therefore, 1865 Jinling Edition Geometry Elements 15 Volume and 1867 Jinling Edition Gu Ze Xi Zhai Arithmetic 24 Volume were published one after another. At the same time (1866), Li Hongzhang (1823-6544), who founded Jinling Machinery Bureau in Nanjing,
1866, Astronomical Arithmetic Museum was merged into Shi Jing Wentong Museum. Li was recommended by Guangdong Governor Guo Songtao (1817-1891) as the head of astronomical arithmetic, but Li was busy publishing books in Nanjing until 188. From then on, he turned to mathematics education and research completely until 1882 died. During this period, there were about 100 students. Oral instruction and finger painting have been going on for more than ten years. Students are all successful in their studies, or are officials from other provinces, or travel abroad "("Cui Jingchang's Uncle Li Junchuan "), and celebrities include Gan, Xiong Fangbai, Chen Shoutian, etc. In his later years, two of his favorite students, Jiang Huaiting and Cai Xiyong, wrote to China and said, "There is nothing more gratifying than this, and I am anxious to tell you." These people have played an important role in spreading modern science, especially mathematics knowledge.
After Li arrived at the museum, he was awarded the title of "Zhongshu in the branch library of Zhongshu" the following year (1869), 187 1 year, 1874 was promoted to the position of the Minister of Foreign Affairs, and 1877 was awarded the title of Minister of Foreign Affairs. For a time, all the "famous officials and great scholars" in the capital made friends with them, and their reputation was greatly improved (Jiang's Poems of Huaiting). However, he still tirelessly engaged in the teaching work of Wentong Library, immersed in academic works. 1872, he published the method of testing numbers, 1877, he solved algebra problems. A few months before his death, he was "still working on the second volume of Pythagoras series, so old and diligent" (Cui Jingchang
Li's research achievements in mathematics are mainly found in his book Xizhai Arithmetic 13, 24 volumes, and the Chagen Law entitled Xizhai Arithmetic 14. Gu Zexi's Arithmetic was published in 1867, which contains his various works on celestial arithmetic in recent 20 years. There are Fiona Fang 1 volume (1845), Revealing Arrow 2 volumes (1845), Logarithmic Exploration 2 volumes (1845), Superimposed Correlation 4 volumes and Quaternary Solution 2 volumes. Elliptic Addendum 3, 1 true tactics of rolling firearms (1858), 1 explanation of the change of logarithmic cone, 1 regression of rolling sequence, 1 rolling field or text, 1 rolling number method. Li's other mathematical works include Interpretation of the Round Sea Mirror, Diagram of the Round Sea Mirror, Nine-volume Diagram, Arithmetic Course in the Museum, Zhu Fuzhen and so on.
Li's mathematical achievements mainly include three aspects: sharp cone skills, stacking skills and prime number theory.