6Intel.Voltage regulator module(VRM)and enterprise voltage regu-lator-down(EVRD)11.1 design guidelines[EB/OL].[2011-09-20].http://www.intel.com/Assets/PDF/designguide/397898.pdf.
7You'an Cao. Automorphisms of certain Lie algebras of upper triangular matrices over a commutative ring[J]. Journal of Algebra, 1997, 189:506-513.
8You'an Cao. Automorphisms of the Lie algebra of strictly upper triangular matrices over certain commutative rings[J].Linear Algebra Appl, 2001, 329:175-187.
9You'an Cao, Zuowen Tan.Automorphisms of the Lie algebra of strictly upper triangular matrices over a commutative ring[J].Linear Algebra Appl, 2003, 360:105-122.
10Gibbs J A. Automorphisms of certain unipotent groups[J].J Algebra, 1970, 14:203-228.