Deng Yajun, the first PhD student jointly trained by Institute of Ocean Research and College of Engneering, Peking University, graduated successfully in July 2018. Deng Yajun's advisor is Professor Lu Hailong. He will continue to pursue his postdoctoral research work in Professor Lu's research group. Since the launch of the enrollment work in 2014, Institute of Ocean Research has successively recruited and trained 10 doctoral candidates with the relevant departments of Peking University, which has effectively promoted the construction of the marine discipline and the development of interdisciplinary subjects at Peking University.

Recently, Deng Yajun's dissertation, The Wetting Characteristics of Mineral Surfaces at Microscale, was awarded as the excellent doctoral dissertation of Peking University in 2018. For better understanding the wetting mechanism of mineral surfaces at microscale, the experimental and simulation studies have been comprehensively conducted in his present work to investigate the micro-nano scale wetting characteristics of several mineral crystals such as quartz. Wetting and dewetting are ubiquitous interface phenomena in our daily life and industry. The wetting ability of a mineral surface plays an essential role in affecting various production processes such as mineral floatation and the exploitation of oil, gas, and gas hydrate resources. Although wetting occurs in a nanoscale area near the triple-phase contact line, previous studies about the wettability of a mineral surface were mainly based on traditional optical methods and investigated the macroscopic wetting characteristics. Therefore, studying the wetting characteristics of mineral surfaces at microscale is of great significance for understanding the mechanism of wetting and dewetting, the factors affecting the mineral wettability, and the contact angle hysteresis phenomenon. Moreover, it is with significance for improving the actual industrial production such as enhanced oil recovery.

Yajun Deng is sharing his research progress

Deng Yajun's road to a PhD is not always roses all the way. Since his main experiments are based on atomic force microscope (AFM), whether stable and reliable experimental results can be obtained is strongly dependent on the setting of instrument parameters, which requires constant debugging. "I used to do experiments day after day from morning till night, but I didn't get any results. All I got was some random data and it felt like a crash," he said, "Fortunately, I persevered, and the experiment gradually went smoothly, and I had a deeper understanding of my own topic."

Students at junior may face the same dilemma in future research. Deng Yajun said, "It is normal that there is no progress in the experiment at this stage, and it is also progress without progress. At least you should know what method is wrong. It is difficult for basic research to see great application value in a short period of time like applied research, which is determined by the nature of research. If you feel confused about the experiment, you will find the answer by communicating and consulting with your tutor. Sometimes research is really hard, be patient! Persistence pays off."

Looking back on the long learning process of five years, Deng Yajun feels strongly. On the teaching resources and academic research platform provided by the institute of Ocean Research, he can find his own space in the ocean field even if he had majored in thermal energy and resource engineering. Along the way, the strong support and understanding of his family, the academic and life guidance of his mentor, the attention and care of the Institute of Ocean Research, the free academic atmosphere and the striving and progressive scientific research environment in Peking University, have all become the driving force for Deng to advance on the scientific research road. We sincerely hope that the students of the institute will continue to work hard and forge ahead, and to contribute to the marine research in China.

PhD Supervisor: Professor Lu Hailong

Lu Hailong, Professor of Peking University Institute of Ocean Research and College of Engineering. Professor Lu has been engaged in the forefront of scientific research for many years. In 2017, he served as the chief scientist of China's first offshore tiral mining of gas hydrate project. The research group and laboratory led by Professor Lu mainly focus on the research of natural gas hydrates. At present, they mainly focus on basic physics and chemical properties, as well as hydrate production simulation.