Construction of lattice orders on the semigroup ring of a positive rooted monoid

Lattice orders on the semigroup ring of a positive rooted monoid are constructed, and it is shown how to make the monoid ring into a lattice-ordered ring with squares positive in various ways. It is proved that under certain conditions these are all of the lattice orders that make the monoid ring into a lattice-ordered ring. In particular, all of the partial orders on the polynomial ring A[x] in one positive variable are determined for which the ring is not totally ordered but is a lattice-ordered ring with the property that the square of every element is positive. In the last section some basic properties of d-elements are considered, and they are used to characterize lattice-ordered division rings that are quadratic extensions of totally ordered division rings.     

Criteria for a ring to have a left Noetherian left quotient ring

Two criteria are given for a ring to have a left Noetherian left quotient ring (to find a criterion was an open problem since 70's). It is proved that each such ring has only finitely many maximal left denominator sets.     

Repeated-root cyclic and negacyclic codes over a finite chain ring

We show that repeated-root cyclic codes over a finite chain ring are in general not principally generated. Repeated-root negacyclic codes are principally generated if the ring is a Galois ring with characteristic a power of 2. For any other finite chain ring they are in general not principally generated. We also prove results on the structure, cardinality and Hamming distance of repeated-root cyclic and negacyclic codes over a finite chain ring.     

Corrugation of a flexible ring under external hydrostatic compression

The initial non-linearly elastic stage of a change in the shape of thin flexible ring under an external hydrostatic pressure is described. At this stage, the formation of alternating bulges and hollows in the ring in a circular direction is due to the balance of non-linearity and dispersion effects. A model is proposed which enables the dependence of the curvature of the deformed ring on the external pressure to be obtained. The shape of the ring is established from the known curvature by methods of differential geometry. Possible types of corrugation of the initial circular ring are obtained. The change in the shape of the ring around a rigid rod, placed inside the ring, is described. The strict relation between the amplitude of the bulges and hollows in the circumferential direction of the ring also prevents the formation of rigid edges on its surface.     

*-Orderings on a ring with involution

The object of the paper is to extend part of the theory of *-orderings on a skewfield with involution to a general ring with involution. The valuation associated to a *-ordering is examined. Every *-ordering is shown to extend. *-orderings are shown to form a space of signs as defined by Brocker and Marshall. In case the involution is the identity, the ring under consideration is commutative and the *-orderings are just the usual orderings making up the usual real spectrum of a commutative ring as defined by Coste and Roy.     

The stability of a ring under the action of a linear torque,constant along the perimeter

Exact analytical solutions of problems on the static and dynamic forms of the loss of stability of a ring, under the action of a linear torque constant along the perimeter, are found using the consistent equations of the theory of plane curvilinear rods constructed earlier taking account of transverse shears. Two forms of torsion of the ring are examined: the external forces creating a torque remain in the plane of a cross-section of the ring in its initial undeformed state (“dead” forces, case 1) or in its deformed state (“follower” forces, case 2). It is shown that, in the second case, the solution of the static instability problem found is practically identical to the solution of the problem corresponding to the dynamic formulation and is reduced to an examination of the oscillations about the static equilibrium position. In the case of both forms of loading, loss of stability of the ring occurs without deformation of its axial line, with it bending predominantly in the plane of the ring accompanied by a slight distortion. It is established that a study of the forms of loss of stability of the ring for the type of loading considered is only possible using the equations constructed, taking account of transverse shear.     

环上的模糊理想幂格及其强截集诱导的格

给出了环上模糊理想幂格的概念,得到相关性质。进而由环上模糊理想强截集诱导出格,讨论了它不是分配格,但为模格。同时,将环上升为主理想环,得到了模糊理想乘积的强截集等于强截集的乘积,且都为环的理想。最后,讨论了Boolean环的模糊子集为模糊理想与其伴随构成交半格的关系。     

Armendariz Properties Relative to a Ring Endomorphism

For an endomorphism α of a ring R, we introduce the notion of an α-Armendariz ring to investigate the relative Armendariz properties. This concept extends the class of Armendariz rings and gives us an opportunity to study Armendariz rings in a general setting. It is obvious that every Armendariz ring is an α-Armendariz ring, but we shall give an example to show that there exists a right α-Armendariz ring which is not Armendariz. A number of properties of this version are established. It is shown that if I is a reduced ideal of a ring R such that R/I is a right α-Armendariz ring, then R is right α-Armendariz. For an endomorphism α of a ring R, we show that R is right α-Armendariz if and only if R[x] is right α-Armendariz. Moreover, a weak form of α-Armendariz rings is considered in the last section. We show that in general weak α-Armendariz rings need not be α-Armendariz.     

G-dimension over local homomorphisms with respect to a semi-dualizing complex

We study the G-dimension over local ring homomorphisms with respect to a semi-dualizing complex. Some results that track the behavior of Gorenstein properties over local ring homomorphisms under composition and decomposition are given. As an application, we characterize a dualizing complex for R in terms of the finiteness of the G-dimension over local ring homomorphisms with respect to a semi-dualizing complex.     

Smash积为超限左自由正规化扩张的充分条件及其应用

本文给出了代数A与双代数H的Smash积AH是A的超限左自由正规化扩张的一个充分条件．进一步,主要结果被运用到斜半群环、斜群环和量子群Uq（sl（2））从而给出了它们的一些性质．     

Delamination of a two-layer corroded ring under radial vibrations

A two-layer ring, with account of its initial state caused by internal pressure and corrosion, leading to wear, is considered. The ring is subjected to an additional pressure causing its radial vibrations. It is shown that, under certain conditions, there is a vibration frequency at which the delamination of the ring is possible. Expressions are found which determine this frequency as a function of problem parameters, in particular, of the time of corrosive wear.     

Semiring unions of a ring and a half-body

We describe the structure of semirings which are unions of a ring and a half-body.     

除环上无限方阵的对角化

讨论了除环上无限方阵的对角化问题,证明了除环上行列有限方阵等价于一类特殊对角矩阵Dn的两个等价条件。     

除环上无限方阵的分解

对除环上无限方阵的逆方阵作了简单讨论,证明了除环上无限方阵的分解定理.     

除环上无限方阵的分解

对除环上无限方阵的逆方阵作了简单讨论,证明了除环上无限方阵的分解定理．     

除环上rcf方阵的对角化

讨论了除环上ｒｃｆ方阵的对角化问题,证明了除环上ｒｃｆ方阵等价于一在特殊对角矩阵Ｄｍｎ的等价条件。     

Strong cleanness of generalized matrix rings over a local ring

Let K_s(R) be the generalized matrix ring over a ring R with multiplier s. For a general local ring R and a central element s in the Jacobson radical of R, necessary and sufficient conditions are obtained for K_s(R) to be a strongly clean ring. For a commutative local ring R and an arbitrary element s in R, criteria are obtained for a single element of K_s(R) to be strongly clean and, respectively, for the ring K_s(R) to be strongly clean. Specializing to s = 1 yields some known results. New families of strongly clean rings are presented.     

柔性圆环壳在子午面内整体弯曲的复变量方程及细环壳的一般解

在З.Л.Аксельрад(E.L.Axelrad)非轴对称载荷下柔性旋转壳线性方程的基础上,导出了圆环壳在子午面内整体弯曲的复变量方程和相应的细环壳方程.该方程可与钱伟长给出了一般解的В.В.Новожилов(V.V.Novozhilov)轴对称环壳方程相类比.通过类比,给出了细环壳在子午面内整体弯曲的一般解.所给出的解可以用来计算波纹管整弯曲的应力和端面位移.     

Flatness and injectivity of simple modules over a commutative ring

In this short paper, the homological functors are used to show that a simple module is flat if and only if it is injective. It is used to give a characterization of Von Neumann regular ring, that is, a commutative ring is Von Neuman regular if and only if every simple module is injective.