Visiting scientist, ICTP, Trieste, Italy, supported by ICTP,  
Jan. to Feb. 1990

Invited visit, Graz Univ., Graz, Austria, supported by Prof. C. B. Lang,  
Mar. 13 to 18, 1990

Invited talk, Technical Univ. of Vienna, Vienna, Austria,  
supported by Prof. H. Markum,  
Mar. 18 to 20, 1990

Visiting scientist and invited talk, Free Univ., Berlin, Germany,  
supported by DAAD, invited by Prof. V. Linke, 
Mar. 21 to Apr. 19, 1990

Invited visits and invited talks,  Waseda Univ. and Tokuyama Univ., Japan,  
supported by Prof. M. Namiki, K. Okano and DFG,  
Apr. to May 1992

Invited visits and invited talks,
Waseda Univ., Tokyo Metropolitan Univ. and Tokuyama Univ., Japan, 
supported by Prof. M. Namiki, H. Minakata, K. Okano and DFG,  
Apr. to May 1994

Invited talk, Essen Univ.,  Essen, Germany, supported by Dr. U. Ritschel,  
Apr. (two days), 1994

Invited visit, Essen Univ., Essen, Germany, supported by Dr. U. Ritschel,  
Jun. (one week), 1994

Invited talk, Mainz Univ., Mainz, Germany, supported by Dr. B. Duenweg,  
Oct. (two days), 1995

Invited talk, Wuppertal Univ., Wuppertal, Germany, supported by Prof. P. Grassberger,  
Nov. (one day), 1995

Invited talk, Halle Univ., Halle/s, Germany, supported by Prof. S. Trimper, 
Jul. 22 to 28, 1997

Invited talk, Siegen Univ., Siegen, Germany, supported by Prof. L. Schuelke,  
Dec. (one week), 1997

Invited visits, Siegen Univ., Siegen, Germany,  
supported by Siegen Univ., invited by Prof. L. Schuelke, 
Jan. 1998 to Apr. 1999, two or three weeks for every two months

Colloquium, Free Univ., Berlin, Germany,  
supported by Free Univ., invited by Prof. V. Linke,  
Dec. 17 to 19, 1998

Invited talk, Institut fuer Festkoerperforschung, Juelich, Germany,  
supported by Dr. G. M. Schuetz,  
Feb. 3 to 5, 1999

Invited visit, Duesseldorf Univ., Duesseldorf, Germany, supported by Prof. H.K. Janssen, Feb. 4 to 5, 1999

Invited visits, Free Univ., Berlin, Germany, supported by Prof. V. Linke,  
Jun. 1999 to 2001.10, some days for every month.

Visiting scientist, Institute for Theoretical Physics,Beijing, China,  
supported by NNSF,  
Jan. to May 2000

Visiting scientist, ICTP, Trieste, Italy, supported by ICTP and L. Yu,  
Jan. 13 to Apr. 17, 2001

Invited visit, Halle Univ., Halle/s, Germany, supported by Prof. S. Trimper, 
Dec, 2002 to Jan. 2003

Invited visit, Halle Univ., Halle/s, Germany, supported by Prof. S. Trimper, 
Dec, 2004 to Jan. 2005

Invited talkKassel Univ., Kassel, Germany, supported by Prof. D. Kolb, 
Jan. 24-26, 2005;

Invited talkLeipzig Univ., Leipzig, Germany, supported by Prof. W. Janke, 
Feb. 3, 2005;

Invited talk, Center of Theo. Sci., Xinzhu, Taiwan, supported by Prof. CH Chang,
May 13, 2005

Invited talk, Central Univ., Zhongli, Taiwan, supported by Prof. HC Lee,
May 16 - 18, 2005

Invited talk, Zhongxinh Univ, Taizhong, Taiwan, supported by Prof. SS Liaw,
May 19 - 20, 2005

Invited visit, ICTP, Trieste, Italy, supported by ICTP,
July 11 - Sep. 16, 2005

Invited visit and talk, Halle Univ., Halle, Germany supported by Prof. S Trimper,
Aug. 8 - 12, 2005

Invited visit, NIMS, Tsukuba, Japan, supported by Prof. X Hu,
Jan. 20 Feb. 19, 2006

Invited talk, Tokuyama Univ., Tokuyama, Japan, supported by Prof. K Okano,
Feb. 9-12, 2006

Invited talk, Tokyo Metropolitan Univ., Tokyo, Japan, supported by Prof. Y Okabe,
Feb. 13, 2006

Invited talk, Waseda Univ., Tokyo, Japan, supported by Prof. H. Nakazato,
Feb. 17, 2006

Invited visit, Nat. Univ. Singapore, Singapore, supported by Prof. JS Wang,
Feb. 19 - 26, 2006

Invited visit, APCTP, Pohang, Korea, supported by APCTP and Xin Zhou,
July 20 - Nov. 20, 2010

Invited visit, Center of Theo. Sci., Taiwan, supported by Prof. HC Lee,
July 25 - Aug. 15, 2011

Invited visit, TU-Berlin and Leipzig Univ., Germany, supported by Prof. W. Janke,  Nov. 7 - 13, 2012

Invited visit, Institute of Physics, Taiwan, supported by Prof. M. K. Wu,  
April. 8-15, 2012

Invited visit, TU-Berlin and Leipzig Univ., Germany, supported by Prof. W. Janke, Nov. 7-13, 2012

Invited visit, National Univ. of Singapore, supported by Dept. Phys.,  
Aug 15-21, 2013

Invited visit, National Univ. of Singapore, supported by Prof. Yang Zhao,  
June 13 - July 13, 2014

Invited visit, UCLA, USA, supported by Prof. Ren Sun, Aug. 3-31, 2014

Invited visit, National Univ. of Singapore, supported by Prof. Yang Zhao,  
Feb. 11 - March 9, 2015

Invited visit, National Univ. of Singapore, supported by Prof. Yang Zhao,  
April 12 - May 7, 2015

Invited visit, National Central University, Taiwan, supported by Prof. M. F. Luo, June. 19 - 26, 2015

Invited visit, Institute of Physics, Taiwan, supported by Prof. C. K. Hu,  
Aug. 11 - 22, 2015