The XX and Ising Limits in Integral Formulas for Finite-Temperature Correlation Functions of the XXZ Chain

We consider a multiple-integral representation for a one-parameter generating function of the finite temperature S^z-S^z correlation functions of the antiferromagnetic spin-1/2 XXZ chain in the XX limit and in the Ising limit. We show how the multiple integrals reduce to single integrals in these limits, thus reproducing known results. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 146, No. 1, pp. 146–160, January, 2006.     

Automorphisms and fusion in finite groups

We study how the fixed point subgroup of an automorphism influences the structure of a group.     

信息熵增量最小化准则在供应链中的应用

本文研究了在考虑利润最大化准则和信息熵增量最小准则下，既能满足了利润最大化，又要增加利润可得性，销售商如何确定订购量的问题。数字实验表明：考虑双重准则得到的策略比仅考虑利润最大化准则得到的策略更好，可以使供应链、销售商及制造商都受益。     

Group classification of the dispersion equation of gaseous pollutants in presence of a temperature inversion

The Lie group method is applied to make a group classification of the PDE governs the dispersion of gaseous pollutants in the presence of a temperature inversion and obtained on a great varity of analytical solutions. The pollutants are assumed to be spread in the layer bounded by the ground surface and the inversion level and they are driven by wind in the horizontal direction. The general solution has been specified for two cases; (i) the ground absorbs all the gaseous pollutants and (ii) the ground does not absorb any pollutant.     

Performance analysis of a batch service queue arising out of manufacturing system modelling

In this paper, we present an exact analysis of a queueing system with Poisson arrivals and batch service. The system has a finite numberS of waiting places and a batch service capacityb. A service period is initialized when a service starting thresholda of waiting customers has been reached. The model is denoted accordingly byM/G ^[a,b] /1–S. The motivation for this model arises from manufacturing environments with batch service work stations, e.g. in machines for computer components and chip productions. The method of embedded Markov chain is used for the analysis, whereby a representation of the general service time is obtained via a moment matching approach. Numerical results are shown in order to illustrate the dependency of performance measures on special sets of system parameters. Furthermore, attention is devoted to the issues of starting rules, where performance objectives like short waiting time, small blocking probability and minimal amount of work in progress are taken into account.     

Effect of strain on vibrational modes in strained layer superlattices

We have investigated the lattice vibrational properties of a two-component strained layer semiconductor superlattice (GaAs) _n1 (GaSb) _n2 using a one-dimensional linear chain model and transfer matrix method [1]. Effect of strain, arising due to the lattice mismatch (∼ 7%) has been considered explicitly in the equation of motion. We show for the first time that the optical vibrational frequency increases (in the case of (GaAs)₄ (GaSb) _n ) or decreases (in the case of (GaAs) _n (GaSb)₄) with increase of layer thicknessn, in either type of superlattices. Raman scattering measurements on some other similar systems support our findings.     

An inequality for the group chromatic number of a graph

We give an inequality for the group chromatic number of a graph as an extension of Brooks’ Theorem. Moreover, we obtain a structural theorem for graphs satisfying the equality and discuss applications of the theorem.     

Poly(N-n-butylitaconimide). Preparation and characterization

Poly(N-n-butylitaconimide) was prepared by radical polymerization in benzene and in bulk at 60°C and was subsequently fractionated at 30°C with benzene and methanol as solvent and nonsolvent, respectively. Relationships between molecular weight and intrinsic viscosity (Mark-Houwink-Sakurada equations) in tetrahydrofuran, benzene, and toluene at 30°C are established. From the Burchard-Stockmayer-Fixman plot, the characteristic ratio of this polymer is determined, and local chain conformation is discussed in relation to the termination process in radical polymerization. © 1993 John Wiley & Sons, Inc.     

自由边界双原子链的晶格振动

指出双原子的晶格振动分为声学支和光学支是由于采用循环边界条件所造成的结果，若采用自由边界条件，则模花样和振动频谱完全不同，这时只能分为低频支，中频支和高频支。     

Integrated Production and Distribution Planning for Södra Cell AB

In this paper we consider integrated planning of transportation of raw material, production and distribution of products of the supply chain at Södra Cell AB, a major European pulp mill company. The strategic planning period is one year. Decisions included in the planning are transportation of raw materials from harvest areas to pulp mills, production mix and contents at pulp mills, distribution of pulp products from mills to customer via terminals or directly and selection of potential orders and their levels at customers. Distribution is carried out by three different transportation modes; vessels, trains and trucks. We propose a mathematical model for the entire supply chain which includes a large number of continuous variables and a set of binary variables to reflect decisions about product mix and order selection at customers. Five different alternatives regarding production mix in a case study carried out at Södra Cell are analyzed and evaluated. Each alternative describes which products will be produced at which pulp mills.