[],,[]1,,,,,,,,,,,2090,,,,,,2,,,,;3,,;3,,;3,,()(),,;3,3,,,,,,,,1,,,,,,4,4.12NS1,S2,,SnY1,Y2,,Yn,u1,u2,,un,,u04.23,NS1,S2,,SnY1,Y2,,Yn,S1u1,S2,S2u1,,SnSnYnunu0862©1994-2008ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(),,,,,,,,,,,,,,,,,,,,,4,,,();,,,;,,,,,,,;,,,,;[1],.[M].:,20031[2],.[J].2005,(3).[3],.[M].:2005.[4].[M].:,20001962©1994-2008ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.