分面浏览：发表日期 |
| 当前检索式 | ((ALL：characterization)) |
| 限定条件 | ((专题：北京大学)) |
| 2017 117 | 2016 139 | 2015 160 |
| 2014 137 | 2013 133 | 2012 132 |
| 2011 118 | 2010 88 | 2009 95 |
| 2008 105 | 2007 105 | 2006 89 |
| 2005 86 | 2004 91 | 2003 72 |
| 2002 78 | 2001 65 | 2000 58 |
| 1999 35 | 1998 55 | 1997 33 |
| 1996 20 | 1995 17 | 1994 5 |
| 1993 12 | 1992 4 | 1991 4 |
| 1990 1 | 1989 2 | 1988 1 |
| 1987 1 | 1986 4 | 1982 1 |
| 1981 1 | 1980 1 |
