实二次域上正定偶幺模格的类群

本文综合利用邻格方法及Siegel mass公式证明了实二次域Q（√d)上∨≌In(n≥4)内的偶幺模格类数为2当且仅当Q（√3）,n=4及Q（√5），n=8。     

实二次域上正定偶幺模格的类数

本文综合利用邻格方法及Siegel　mass公式证明了实二次域Q( )上 内的偶幺模 格类数为2当且仅当Q( ),n=4及Q( ).n=8.     

不可分的正定幺模Hermite型的构作

本文给出了构作Z[m^1/2i]上不可分的正定幺模n秩Hermite格当m?3(mod4)时的方法.对任何自然数n,除了n=2,3,4,5(n=2,3)的例外情形,证明了存在Gauss整环Z[i](整环Z[2^1/2i])上不可分的正定幺模n秩正规Hermi-te格并给出它们的明显结构.又对任何n=4k(n=2k)构作了Z[i][(Z2^1/2i])上不可分的正定幺模n秩偶Hermite格.     

Q(√6)上的定幺模格的分类

利用推广的邻格方法,完成了Q(√6)上秩4的在一个阿基米德除子上正定,在另一阿基米德除子上负定的所有幺模格种的分类.     

关于Q(√/4k2x+1)的理想类群的循环子群

设d,a,k,n是适合4k2n+1 =da2, k>1, n>2, d无平方因子的正整数;又设C(K)和h(K)分别是实二次域K=Q(√d)的理想类群和类数.本文证明了:当a<0.5k0.56n时,则h(K)≡0(mod n)和C(K)必有n阶循环子群.     

也谈符号^n√a究竟表示什么？

众所周知,在实数系,符号n(√a)有明确的意义:如果a＞0,n(√a)表示一个正数,它的n次方等于a,即n(√a)＞0,且(n(√a))n=a.这时,n(√a)表示a的n次算术根.如果a=0,n(√a)=0,如果a＜0.当n是奇数时,n(√a)=-n(√-a)这里的n(√-a)是正数-a的n次算术根,当n是偶数时,n(√a)没有意义.     

On the exceptional fields for a class of real quadratic fields

In this paper, we give a lower bound exp(2.2 × 10~8 ) for those discriminants of real quadratic fields Q(√ d) with d= N~2-4 and h(d)=1.     

8-rank of the class group and isotropy index

Suppose F = Q(√-p1 pt) is an imaginary quadratic number field with distinct primes p1,..., pt,where pi≡ 1(mod 4)(i = 1,..., t- 1) and pt ≡ 3(mod 4). We express the possible values of the 8-rank r8 of the class group of F in terms of a quadratic form Q over F2 which is defined by quartic symbols. In particular,we show that r8 is bounded by the isotropy index of Q.     

Stability of planar diffusion wave for the quasilinear wave equation with nonlinear damping

In this paper, we will show that under some smallness conditions, the planar diffusion wave v(√x11+) is stable for a quasilinear wave equation with nonlinear damping: vttt-f(v) + vt + g(vt) = 0, x =(xn1, x2,, xn)∈ R, where v(√x11+) is the unique similar solution to the one dimensional nonlinear heat equattion: vt-f(v)x1x1= 0, f ′(v) > 0, v(±∞, t) = v±, v+ = v-. We also obtain the L∞ time decay rate which rreads v-v L∞= O(1)(1 + t)-4, where r = min{3, n}. To get the main result, the energy method and a new inequality have been used.     

虚二次域Q(√1-4kn)类数整除性的例外情况

设d是无平方因子正整数,hK是虚二次域K=Q(√-d)的类数.又设d满足1+ da2=4kn,其中a,k,n是适合k＞1,n＞2的正整数.运用初等数论方法给出了数组(d,a,k,n)可使n|hK成立的必要条件.     

An Analogue of Distributivity for Ungraded Lattices

In this paper, we study lattices that posess both the properties of being extremal (in the sense of Markowsky) and of being left modular (in the sense of Blass and Sagan). We call such lattices trim and show that they posess some additional appealing properties, analogous to those of a distributive lattice. For example, trimness is preserved under taking intervals and suitable sublattices. Trim lattices satisfy a weakened form of modularity. The order complex of a trim lattice is contractible or homotopic to a sphere; the latter holds exactly if the maximum element of the lattice is a join of atoms. Any distributive lattice is trim, but trim lattices need not be graded. The main example of ungraded trim lattices are the Tamari lattices and generalizations of them. We show that the Cambrian lattices in types A and B defined by Reading are trim; we conjecture that all Cambrian lattices are trim.     

模糊幂格

本文研究了格向其模糊幂集上提升的问题.利用模糊集理论,引入了模糊幂格的概念,获得了模糊幂格及其模糊理想的若干基本性质,推广了格的结果.     

Interpreting arithmetics in the ideal lattice of a free vector lattice ℱ<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript>

A vector space V over a real field R is a lattice under some partial order, which is referred to as a vector lattice if u + (v ∨ w) = (u + v) ∨ (u + w) and u + (v ∧ w) = (u + v) ∧ (u + w) for all u, v, w ∈ V. It is proved that a model N of positive integers with addition and multiplications is relatively elementarily interpreted in the ideal lattice ℱ _n of a free vector lattice ℱ _n on a set of n generators. This, in view of the fact that an elementary theory for N is hereditarily undecidable, implies that an elementary theory for ℱ _n is also hereditarily undecidable. __________ Translated from Algebra i Logika, Vol. 47, No. 1, pp. 71–82, January–February, 2008.     

幂格与幂集格的关系

由幂格的定义知 ,幂格与幂集格是不同的 ,然而它们却有一定的联系 .本文在幂格概念的基础上 ,进一步地讨论幂格和幂集格在一定条件下的联系 .     

分配格中理想诱导的幂格

本文在文 [1 ]的基础上 ,给出由分配格中理想诱导的两种幂格 .     

幂格的同态与同余关系

本文在文[1]已引入幂格同态概念的基础上，进一步引入幂格同余关系的概念，并得到它们的一些相关性质．以及幂格同态与幂格同余关系的对应关系．     

分配格中模糊理想诱导的模糊幂格

在模糊幂格讨论基础上,给出了由分配格中模糊理想诱导的两种模糊幂格.     

模糊幂格的素理想与素对偶理想

讨论格与其模糊幂格的理想,对偶理想的关系,以及格与其模糊幂格的素理想,素对偶的关系.     

幂格与商格的关系

该文在文［1］中幂格概念的基础上,得到了幂格的一个充要条件,给出了正则幂格、相对幂格的概念,并讨论了商格与正则幂格、相对幂格的关系.〖HT5”H〗关键词:〖HT5”SS〗格;幂格;商格;正则幂格;相对幂格.