广义(m,n)超环

本文研究了广义(m,n)超环,n元正则关系以及n元强正则关系等的一些性质.利用广义(m,n)超环间的同态关系以及正则和强正则关系,得到了(m,n)子超环和(m,n)超理想的不变性,广义(m,n)超环的商结构,以及构成商超环和商环的充分必要条件,推广了文献[5]的一些结果.     

Erratum to “Fuzzy rough set model on two different universes and its application” [Appl. Math. Model. 35 (4) (2011) 1798–1809]

The aim of this paper is to correct two mistakes in [Appl. Math. Model. 35 (4) (2011) 1798–1809], which are: one of the properties of fuzzy rough set between two different universes and the definition of the upper approximation with the property for degree fuzzy rough set between two different universes.     

Extended thermodynamics of real gases with dynamic pressure: An extension of Meixnerʼs theory

Basing on the recent theory of extended thermodynamics of dense gases, we study a thermodynamic theory of gases with the energy transfer from molecular translational mode to internal modes as an extension of Meixner?s theory. We focus our attention on the simplest case with only one dissipative process due to the dynamic pressure. The dispersion relation for sound derived from the present theory is compared with that from Meixner?s theory. Kinetic theoretical basis of the present approach is also discussed.     

高应变率下计及损伤演化的材料动态本构行为

材料在高速变形过程中常常伴有不同形式的内部缺陷或微损伤的演化。大量的实验观察表明,损伤演化同时依赖于应变、应变率和温度,而且高应变率和低温之间有某种等价性。由此基于热激活机制,提出了同时依赖于应变率和应变的微损伤演化律,及相应的计及损伤弱化效应的率型本构关系。以聚丙烯/尼龙（PP/PA）共混高聚物为例,具体研究了其计及损伤演化的ZWT本构关系,并区分其率相关的本构响应及率相关的损伤演化响应。     

On the normalizing groupoids and the commensurability groupoids for inclusions of factors associated to ergodic equivalence relations–subrelations

It is shown that for the inclusion of factors corresponding to an inclusion of ergodic discrete measured equivalence relations , is normal in in the sense of Feldman–Sutherland–Zimmer [J. Feldman, C.E. Sutherland, R.J. Zimmer, Subrelations of ergodic equivalence relations, Ergodic Theory Dynam. Systems 9 (1989) 239–269] if and only if A is generated by the normalizing groupoid of B. Moreover, we show that there exists the largest intermediate equivalence subrelation which contains as a normal subrelation. We further give a definition of “commensurability groupoid” as a generalization of normality. We show that the commensurability groupoid of B in A generates A if and only if the inclusion BA is discrete in the sense of Izumi–Longo–Popa [M. Izumi, R. Longo, S. Popa, A Galois correspondence for compact groups of automorphisms of von Neumann algebras with a generalization to Kac algebras, J. Funct. Anal. 155 (1998) 25–63]. We also show that there exists the largest equivalence subrelation such that the inclusion is discrete. It turns out that the intermediate equivalence subrelations and thus defined can be viewed as groupoid-theoretic counterparts of a normalizer subgroup and a commensurability subgroup in group theory.     

理想导体与均匀绝缘介质分界面上边值关系独立性的讨论

提供了一种由理想导体与均匀绝缘介质(或真空)分界面上的边值关系en.D=σf导出另一边值关系en×H=αf的方法.     

离子注入硅片快速退火后的红外椭偏光谱研究

离子注入硅片经高温退火后晶体结构缺陷会被修复,其在可见光波段下的光学性质趋于单晶硅,常规的可见光椭偏光谱法对掺杂影响的测量不再有效.本研究将测量波段扩展到红外区域(2—20μm),报道了利用红外椭偏光谱法测量经离子注入掺杂并高温退火的硅片掺杂层光学和电学性质的方法和结果.通过建立基于Drude自由载流子吸收的等效光学模型,得到了杂质激活后掺杂层的杂质浓度分布、电阻率和载流子迁移率等电学参数,以及掺杂层的红外光学常数色散关系,分析了这些参数随注入剂量的关系并对其物理机理给予了解释.研究表明,中远红外椭偏测量是表征退火硅片的有效方法,且测量波长越长,所能分辨的掺杂浓度越低.     

Effect of nonlinearity on the steady motion of a twinning dislocation

We consider the steady motion of a twinning dislocation in a Frenkel-Kontorova lattice with a double-well substrate potential that has a non-degenerate spinodal region. Semi-analytical traveling wave solutions are constructed for the piecewise quadratic potential, and their stability and further effects of nonlinearity are investigated numerically. We show that the width of the spinodal region and the nonlinearity of the potential have a significant effect on the dislocation kinetics, resulting in stable steady motion in some low-velocity intervals and lower propagation stress. We also conjecture that a stable steady propagation must correspond to an increasing portion of the kinetic relation between the applied stress and dislocation velocity.     

Incomplete pairwise comparison and consistency optimization

This paper proposes a new method for calculating the missing elements of an incomplete matrix of pairwise comparison values for a decision problem. The matrix is completed by minimizing a measure of global inconsistency, thus obtaining a matrix which is optimal from the point of view of consistency with respect to the available judgements. The optimal values are obtained by solving a linear system and unicity of the solution is proved under general assumptions. Some other methods proposed in the literature are discussed and a numerical example is presented.     

Estimating molecular masses of petroleum-derived fractions: High mass (>2000 u) materials in maltenes and asphaltenes from Maya crude oil

Molecular mass ranges and average masses of fractions from a heavy Mexican crude oil (Maya) have been studied, using mainly size exclusion chromatography (SEC) and laser desorption-mass spectrometry (LD-MS). Method development focused on the use of planar chromatography and size exclusion chromatography (SEC), to isolate narrow bands of material from solubility-separated fractions of the crude oil. The procedure provides a planar chromatography based method for studying mass ranges in complex hydrocarbon mixtures. It allows the calculation of ‘best estimate’ values for number and mass-averages. These can then be used in average structural parameter (ASP) calculations, for studying structural features of the samples. The method is applicable to both coal and petroleum-derived samples. The molecular mass estimates arrived at in this work for petroleum-derived samples are considerably higher than those reported by other workers for similar samples. The results presented here provide strong evidence for the presence of ions approaching m/z 10,000 in the Maya asphaltene. The maltene fraction was found to contain a small amount of ions with mass (m/z) in excess of 2000.