李代数

Secondly, it has drawn out the pointed YD-Lie algebras definition, in the category of Yetter-Drinfeld modules, let Z be a torsion-free abelian group, if we have a symmetric braiding c, for each G-graded algebra V over the G-graded space, a new Lie superalgebra with an operation _c satisfying an actions, then we can obtain a new Lie superalgebra, this paper to call it pointed YD-Lie algebra.

其次引出了点YD-李代数，即：在Yetter-Drinfeld模范畴中，对任意的一个G-分次代数Z(G为无挠群V，引入对称辫子c后，在V内作_c运算，即可得到一种新的李代数(本文称之为点YD-李代数)。

Assume a Lie algebra g has a form B which has all the useful properties of Killingform:bilinearity nondegeneracy,symmetry and invariance.Note that for such a Liealgebra the adjoint representation is equivalent to the coadjoint representation.We callit a symmetric self-dual Lie algebra and the form B an invariant scalar product.

在第一部分的最后一节，我们引进了拟Heisenberg代数的概念，证明了这些李代数均为具有非极大秩的CN李代数，进一步我们还证明了这些CN李代数构成的集合与极大秩幂零李代数构成的集合之间存在着1-1对应关系。

Let R be an arbitrary commutative ring with identity, gl the general linear lie algebra over R consisting of all n × n matricesover R and with the bracket operation = xy -yx, t the lie subalgebraof gl consisting of all n×n upper triangular (resp., strictly upper triangular ) matrices over R and d the lie subalgebra of gl consisting of all n×n diagonal matrices over R.

在第三章中，对R是交换环的情形，讨论了典型李代数的导子代数的结构问题：设R是一个含幺交换环，gl是R上一般线性李代数。t是gl的所有n阶上三角矩阵(相应地，严格上三角矩阵)构成的子代数，d是gl的所有n阶对角阵构成的李代数。

Then we study the typical property of theirs form the starting of nature and constitute of the two types of Lie algebra, and we calculated separately their dimension, center, commutator algebra, Killing type, Cartan subalgebra, structure formula, root system, and so on.

本文主要研究了两类典型的李代数即李代数so*(2n)和g*，首先介绍了一些李代数的基本知识，并且给出了这两类李代数的组成结构，然后从这两类李代数的本质构成出发，研究它们的一些典型性质，分别讨论了它们的维数，中心，换位子代数，Killing型，Cartan子代数，结构公式，根系等。

Libermann.The early researcheson this kind of manifolds were closely related to Physics and Mechanics.But since1991,S.Kaneyuki published his result on the algebraic condition for the existence ofinvariant〓structures on a coset space,Lie theory has played the most impor-tant role in the study of this kind of manifolds.In particular,dipolarizations in a Liealgebra are closely related to the homogeneous〓manifolds.Dipolarizationsin semisimple Lie algebras and the homogeneous〓manifolds associated withthese dipolarizations have been studied by S.Kaneyuki,Z.X.Hou and S.Q.Deng.Inthe partⅡ of this thesis we study the dipolarizations in some quadratic Lie algebrasand the homogeneous parakahler manifolds associated with these dipolarizations.

Libermann给出的，早期的有关类流形的研究与物理和力学密切相关，自从1991年金行壮二发表了陪集空间上存在不变仿凯勒结构的代数化结果后，李群及李代数理论在这类流形的研究中起着主要作用，特别地，李代数的双极化与这类流形密切相关，半单李代数的双极化的相关几何，金行壮二，候自新和邓少强等人已作了研究，二次李代数是比半单李代数更广且带有非退化不变双线性型的李代数，本文主要研究了二次代数的双极化及相关几何。

In Reference [3], Cao and Tan described the automorphisms of Lie algebra of the strictly upper triangular matrices over R which is a maximal nilpotent subalgebra of the A_n type classical simple Lie algebra.

在参考文献[3]中，曹和谭把由所有严格上三角矩阵所构成的李代数的自同构问题已经完整的解决了，而这样的李代数恰好就是A_n型李代数的一个极大幂零子代数。

The solvable Lie algebra is corresponding to a cascade decomposition of the system and the semisimple Lie algebra is corresponding to a qasi-parallel decomposition such that the system has a parallel form of a cascade decomposition and a qasi-parallel decomposition.

任一李代数都可分解为一可解李代数与一半单李代数的半直和，可解李代数对应于系统的级联分解，半单李代数对应的是系统的准平行分解，将二者合并起来，就得到一般李群下的非线性系统的结构分解，这是一级联形式与一准平行形式的并联形式分解。

Throughout the present paper, the author mainly discuss the complexification of n-Lie algebras and the classification of real simple n-Lie algebras.

就李代数而言，单李代数的复化和复李代数的实形是一个非常重要的问题，同时其分类也是人们关注的焦点，本文将这两个结论放在n-李代数中进行深入的研究。

In the fifth chapter,we study dipolarizations in some quadratic Lie algebras.Inthe first section,we obtain some results on the classification of dipolarizations in gen-eral quadratic Lie algebras,and prove that there exist dipolarizations in the solvablequadratic Lie algebras whose Cartan subalgebras consist of semisimple elements.

第五章讨论了某些二次李代数的双极化，在第一节中，我们给出了二次李代数的双极化的一些分类结果；特别证明Cartan子代数是由半单元组成的二次李代数上存在双极化，第二节确定了四维扩张Heisenberg代数的所有双极化，在第三节中，我们构造了2n+2维扩张Heisenberg代数的六类双极化，我们发现两个不同于半单李代数情形的有趣事实：（1）在扩张Heisenberg代数上同时存在对称和非对称双极化；（2）对应于扩张Heisenberg代数的双极化的特征元有的是半单的有的是幂零的。

Part II of this paper studies the structure of symmetric self-dual Lie algebras.

假设李代数g带有一个与Killing具有相同性质的型B，即具有双线性性，非退化性，对称性和不变性，由于这样的李代数g的伴随表示与它的余伴随表示等价，我们称李代数g为对称自对偶李代数，称型B为它上的一个不变数积。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了