The Asymptotic Limit for the 3D Boussinesq System

In this paper, we show the asymptotic limit for the 3D Boussinesq system with zero viscosity limit or zero diffusivity limit. By the classical energy method, we prove that as viscosity(or diffusivity) coefficient goes to zero the solutions of the fully viscous equations converges to those of zero viscosity(or zero diffusivity) equations, which extend the previous results on the asymptotic limit under the conditions of the zero parameter(zero viscosity ν = 0 or zero diffusivity η = 0) in 2D case separately.     

Multiple Forced Rotational Solutions for the Planar N-pendulum Equation

This paper presents a theorem of existence of(N-N_0 + 1)2~(N_0) noncontractible periodic orbits of any given rotational vector with zero components for the planar forced N-pendulum equation, where N0 denotes the number of zero components of given rotational vector. We make special arrangements for masses and length instead of the nondegenerate assumption. Moreover, for rotational vectors with identical components, similar results are also obtained.     

Idempotent bounded C-semigroups

A semigroup with zero isidempotent bounded (IB) if it is the 0-direct union of idempotent generated principal left ideals and the 0-direct union of idempotent generated principal right ideals. Notable examples are completely 0-simple semigroups and the wider class of primitive abundant semigroups. Significant to the structure of these semigroups is that they are all categorical at zero. In this paper we describe IB semigroups that are categorical at zero in terms ofdouble blocked Rees matrix semigroups. This generalises Fountain's characterisation of primitive abundant semigroups via blocked Rees matrix semigroups [1], which in turn yields the Rees theorem for completely 0-simple semigroups.     

Nest代数上的在零点广义可导映射

设A为B（H）的子代数,　是A到B（H）的线性映射,我们说　在0点广义可导（广义双边可导）,如果对任意的S,T∈A且ST=0（ST=0或TS=0）,有　（ST）=　（S）T+S　（T）-S　（I）T.本文主要得到如下结果:（1）有限Nest代数上的每个范数拓扑连续的在0点广义可导的线性映射是广义内导子;（2）若N是完备Nest且H_　 H,则algN上的每个范数拓扑连续的在0点广义双边可导的线性映射是广义内导子.     

On the representation of zero in floating-point arithmetic

Two representations of zero in floating-point arithmetic are considered in relation to a summation with correction for rounding errors. The common representation with exponent zero is shown in this case to be better than the academic representation where the exponent depends on the history of the zero.     

0-对偶预同态的一个充要条件

我们对带零逆半群定义了0-对偶预同态的概念,给出并证明了0-对偶预同态的一个等价条件.     

A SIMPLICIAL ALGORITHM FOR COMPUTING AN INTEGER ZERO POINT OF A MAPPING WITH THE DIRECTION PRESERVING PROPERTY

A mapping f:Z~n→R~n is said to possess the direction preserving property if fi(x)>0implies fi(y)≥0 for any integer points x and y with ‖x-y‖∞≤1.In this paper,a simplicial algorithm is developed for computing an integer zero point of a mappingwith the direction preserving property.We assume that there is an integer point x~0 withc≤x~0≤d satisfying that max_(1≤i≤n)(x_i-x_i~0)fi(x)>0 for any integer point x withf(x)≠0 on the boundary of H={x∈R~n|c-e≤x≤d e},where c and d are twofinite integer points with c≤d and e=(1,1,…1)~∈R~n.This assumption is impliedby one of two conditions for the existence of an integer zero point of a mapping with thepreserving property in van der Laan et al.(2004).Under this assumption, starting at x~0,the algorithm follows a finite simplicial path and terminates at an integer zero point ofthe mapping.This result has applications in general economic equilibrium models withindivisible commodities.     

E*-酉范畴逆半群的一个表示定理

本文,我们对带零逆半群定义了0-对偶预同态的概念,并且用0-对偶预同态刻画了E*-酉范畴逆半群。     

On the Brandt λ 0-extensions of monoids with zero

We study algebraic properties of the Brandt λ ⁰-extensions of monoids with zero and non-trivial homomorphisms between the Brandt λ ⁰-extensions of monoids with zero. We introduce finite, compact topological Brandt λ ⁰-extensions of topological semigroups and countably compact topological Brandt λ ⁰-extensions of topological inverse semigroups in the class of topological inverse semigroups and establish the structure of such extensions and non-trivial continuous homomorphisms between such topological Brandt λ ⁰-extensions of topological monoids with zero. We also describe a category whose objects are ingredients in the constructions of finite (compact, countably compact) topological Brandt λ ⁰-extensions of topological monoids with zeros.     

Integrable coupling hierarchy and Hamiltonian structure for a matrix spectral problem with arbitrary-order

We presented an integrable coupling hierarchy of a matrix spectral problem with arbitrary order zero matrix r by using semi-direct sums of matrix Lie algebra. The Hamiltonian structure of the resulting integrable couplings hierarchy is established by means of the component trace identities. As an example, when r is 2 × 2 zero matrix specially, the integrable coupling hierarchy and its Hamiltonian structure of the matrix spectral problem are computed.     

Finiteness conditions for finitely generated monoids

In this paper, we show that every finitely generated monoid, with a disjunctive zero 0 such that abc=0 implies cba=0, is finite. This research has been supported by Grant A7877 of the National Research Council of Canada.     

辛代数的极大幂零子代数的保李括积零的线性映射

Let F be a field with char F = 2, l a maximal nilpotent subalgebra of the symplectic algebra sp（2m,F）. In this paper, we characterize linear maps of l which preserve zero Lie brackets in both directions. It is shown that for m ≥ 4, a map φ of l preserves zero Lie brackets in both directions if and only if φ = ψcσT0λαφdηf, where ψc,σT0,λα,φd,ηf are the standard maps preserving zero Lie brackets in both directions.     

Multiple forced rotational solutions for the planar <Emphasis Type="Italic">N</Emphasis>-pendulum equation

This paper presents a theorem of existence of \((N - N_{0} + 1)2^{N_{0}}\) noncontractible periodic orbits of any given rotational vector with zero components for the planar forced N-pendulum equation, where N₀ denotes the number of zero components of given rotational vector. We make special arrangements for masses and length instead of the nondegenerate assumption. Moreover, for rotational vectors with identical components, similar results is also obtained.     

The Structure of ℒ-Unipotent Semigroups with Zero

Abstract

We generalise theory of Lawson for inverse monoids with zero to wider classes of regular semigroups. We give a structure theorem for ?-unipotent monoids with zero. Several connections between cancellative categories and 0-E-unitary semigroups are obtained as an application of the results of this paper.     

Orbital topological classification of analytic differential equations in a neighborhood of a degenerate elementary singular point on the two-dimensional complex plane

We consider the germ of an analytic differential equation in (C², 0) defined by a vector field with a singularity at zero. A singular point of the equation is called degenerate elementary if one eigenvalue of the linear part of the field is equal to zero and the other is different from zero. The orbital topological classification of differential equations in a neighborhood of a degenerate elementary singular point is obtained for all cases except the so-called Liouville case. This case defines a subset of equations which does not separate the corresponding function space.Translated from Trudy Seminara imeni I. G. Petrovskogo, No. 13, pp. 137–165, 1988.     

Algebraic Characterization of Dense-Separability Among Compact Spaces

In this note, we show that a compact Hausdorff space X is dense-separable if and only if every family of ideals of C(X) with zero intersection has a countable subfamily with zero intersection. As a consequence of this characterization we observe that every compact dense-separable space whith Soc(C(X)) = 0 has a countable dense and co-dense subset.     

Toroidal varieties and the weak factorization theorem

We develop the theory of stratified toroidal varieties, which gives, together with the theory of birational cobordisms [73], a proof of the weak factorization conjecture for birational maps in characteristic zero: a birational map between complete nonsingular varieties over an algebraically closed field K of characteristic zero is a composite of blow-ups and blow-downs with smooth centers. Dedicated to Professor Andrzej Biaynicki-Birula     

Orthogonal sums of semigroups

The purpose of this paper is to prove that every semigroup with the zero is an orthogonal sum of orthogonal indecomposable semigroups. We prove that the set of all 0-consistent ideals of an arbitrary semigroup with the zero forms a complete atomic Boolean algebra whose atoms are summands in the greatest orthogonal decomposition of this semigroup. Supported by Grant 0401A of RFNS through Math. Inst. SANU.     

严格上三角矩阵李代数上的积零导子

设$F$ 为域, $n\geq 3$, $\bf{N}$$(n,\mathbb{F})$ 为域$\mathbb{F}$ 上所有$n\times n$ 阶严格上三角矩阵构成的严格上三角矩阵李代数, 其李运算为$[x,y]=xy-yx$. $\bf{N}$$(n, \mathbb{F})$ 上一线性映射$\varphi$ 称为积零导子,如果由$[x,y]=0, x,y\in \bf{N}$$(n,\mathbb{F})$,总可推出 $[\varphi(x), y]+[x,\varphi(y)]=0$. 本文证明 $\bf{N}$$(n,\mathbb{F})$上一线性映射 $\varphi$ 为积零导子当且仅当 $\varphi$ 为$\bf{N}$$(n,\mathbb{F})$ 上内导子, 对角线导子, 极端导子, 中心导子和标量乘法的和.     

Mean dimension and AH-algebras with diagonal maps

Mean dimension for AH-algebras with diagonal maps is introduced. It is shown that if a simple unital AH-algebra with diagonal maps has mean dimension zero, then it has strict comparison on positive elements. In particular, the strict order on projections is determined by traces. Moreover, a lower bound of the mean dimension is given in term of Toms' comparison radius. Using classification results, if a simple unital AH-algebra with diagonal maps has mean dimension zero, it must be an AH-algebra without dimension growth. Two classes of AH-algebras with diagonal maps are shown to have mean dimension zero: the class of AH-algebras with at most countably many extremal traces, and the class of AH-algebras with numbers of extreme traces which induce same state on the _K0${\mathrm{K}}_0$-group being uniformly bounded (in particular, this class includes AH-algebras with real rank zero).