Jun's research has been disseminated through a large number of peer-reviewed journal articles, conference presentations, and media outlets. His work has been supported by a variety of funding sources including, among others, National Science Foundation, US Department of Agriculture, Environmental Protection Agency, National Fish and Wildlife Foundation, US Geological Survey, Louisiana Board of Regents, Louisiana Sea Grant College Program, Louisiana Department of Environmental Quality, and National Council for Air and Stream Improvement.

In his research, Jun has collaborated with many researchers from various institutions and different countries. He has given 30+ invited research seminars and was a Visiting Professor at Warsaw University of Life Sciences, Poland. He has been a member of the International Expert Panel of the Chinese Academy of Sciences since 2014 and has been a Senior Affiliated Professor at the Chinese Academy of Sciences since 2011.

Jun has served as committee Chair/Co-Chair for 18 PhD and 21 MS students, as a committee member for 20 PhD and 8 MS students, and as an External Examiner for 4 PhD students in China, 2 Post-Docs in China, 1 PhD student in Germany, and 1 PhD student in Ireland. He has served a faculty host for Fulbright and international scholars and exchange students.