具有Clifford断面的正则纯正半群

给出了具有Clifford断面的右正规纯正半群的等价刻画,得到了具有Clifford断面的正则纯正半群的次直积分解,证明了具有Clifford断面的正则纯正半群一定是正则纯正群．     

CSR电子冷却系统电子束空间电荷效应对电子束温度的影响

通过求解电子冷却系统中冷却段漂移管区的强流电子束产生的空间电荷场,研究了电子束空间电荷效应对电子温升的影响。结合HIRFL CSR电子冷却系统的典型参数,得到了电子在自身空间电荷场和纵向螺线管磁场组成的交叉场作用下产生的漂移速度和由此引起的附加温度大小,并指出减小电子束空间电荷效应的方法。     

On the Congruences in Right Loops

In case the stability relation is a congruence, a necessary and also a sufficient condition for its equality with the center congruence is given.     

Multidimensional Permanents and an Upper Bound on the Number of Transversals in Latin Squares

The permanent of a multidimensional matrix is the sum of products of entries over all diagonals. A nonnegative matrix whose every 1‐dimensional plane sums to 1 is called polystochastic. A latin square of order n is an array of n symbols in which each symbol occurs exactly once in each row and each column. A transversal of such a square is a set of n entries such that no two entries share the same row, column, or symbol. Let T(n) be the maximum number of transversals over all latin squares of order n. Here, we prove that over the set of multidimensional polystochastic matrices of order n the permanent has a local extremum at the uniform matrix for whose every entry is equal to . Also, we obtain an asymptotic value of the maximal permanent for a certain set of nonnegative multidimensional matrices. In particular, we get that the maximal permanent of polystochastic matrices is asymptotically equal to the permanent of the uniform matrix, whence as a corollary we have an upper bound on the number of transversals in latin squares      

同余自由的具有Q-逆断面的正则半群

本文讨论具有逆断面的正则半群的同余格对于它本身结构的影响．　我们给出了这类半群有最简单的同余格，即只有平凡同余的充分必要条件．     

Fredholm Property of Operators from 2D String Field Theory

In a recent study of Landau-Ginzburg model of string field theory by Gaiotto, Moore and Witten, there appears a type of perturbed Cauchy-Riemann equation, i.e. the ζ -instanton equation. Solutions of ζ -instanton equation have degenerate asymptotics. This degeneracy is a severe restriction for obtaining the Fredholm property and constructing relevant homology theory. In this article, we study the Fredholm property of a sort of differential operators with degenerate asymptotics. As an application, we verify certain Fredholm property of the linearized operator of ζ -instanton equations.     

E-special Ordered Regular Semigroups

An ordered regular semigroup S is E-special if for every x ∈ S there is a biggest x ⁺ ∈ S such that both xx ⁺ and x ⁺ x are idempotent. Every regular strong Dubreil–Jacotin semigroup is E-special, as is every ordered completely simple semigroup with biggest inverses. In an E-special ordered regular semigroup S in which the unary operation x → x ⁺ is antitone the subset P of perfect elements is a regular ideal, the biggest inverses in which form an inverse transversal of P if and only if S has a biggest idempotent. If S ⁺ is a subsemigroup and S does not have a biggest idempotent, then P contains a copy of the crown bootlace semigroup.     

具有Clifford断面的纯正半群

本文研究有Clifford断面的纯正半群.为了获得主要的结构定理，证明了纯正半群有群断面当且仅当它是矩形群;利用半格和矩形带，建立了有Clifford断面的纯正半群的结构.     

Multi-transverse Mode Operation in Vertical-cavity Surface-emitting Lasers: Effects of Wideband Modelling on Spectral Characteristics and Noise

A dynamic model for the vertical-cavity surface-emitting laser aimed to study the precise oscillation frequencies of the transverse modes is presented. The model performs the computation of the longitudinal distribution of the field inside the laser cavity, to take account of distributed boundary conditions at the Bragg reflectors. The latter are approximated by means of autoregressive moving-average (ARMA) digital filters, in order to reduce the computational load without loss of precision in wideband scenarios. With the aid of the developed model, a detailed analysis of the frequency and relative intensity noise spectra is carried out, thus allowing to evaluate the spectral quality of the laser emission. Particularly, the results reveal that each of the transverse modes oscillates with a frequency detuning from the central design wavelength, which is in good agreement with experimental observation.     

谈多功能波动演示仪的研制与应用

本文从仪器的结构、原理及使用三方面介绍了最新研制的多功能波动演示仪及其应用。