Yuanjie Gao, female, was born in July 1991 in Linyi, Shandong. I graduated from Qingdao University of Technology in July, 2015, and obtained a bachelor's degree in Vehicle engineering. I was admitted to the College of Mechanical and Automotive Engineering of Qingdao University of Technology in 2020 and studied for a master's degree in mechanical engineering. In 2022, I continued researching on the lubrication behavior of cam-roller unit to get my doctor's degree. My supervisor is Professor Guo Feng.