Extended Bose-Hubbard model with pair hopping on triangular lattice

We study systematically an extended Bose-Hubbard model on the triangular lattice by means of a meanfield method based on the Gutzwiller ansatz. Pair hopping terms are explicitly included and a three-body constraint is applied. The zero-temperature phase diagram and a variety of quantum phase transitions are investigated in great detail. In particular, we show the existence and the stability of the pair supersolid phase.     

KdV方程的延拓结构

利用延拓结构理论讨论KdV方程的解,并且给出了带一个参数的KdV方程,得到了该方程延拓代数对应的Lax对.     

Generalization of the Bardeen-Cooper-Schrieffer method for pair interactions

We consider the transition to temperature-dependent equations for ultrasecond-quantized problems. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 154, No. 3, pp. 584–592, March, 2008.     

基于集对分析的混合型多属性决策方法的研究

针对属性权重信息不完全且属性值为实数、区间数和模糊语言值相结合的混合型多属性决策问题,提出了一种基于集对分析的多属性决策方法.该方法所需计算量较少,方法简单,易于计算.最后通过实例验证了该方法的有效性和实用性.     

黄连素制剂中盐酸小檗碱含量测定的一种新方法

提出了用间接原子吸收法测定黄连素制剂中盐酸小檗碱含量的新方法。     

含SDG对的费米子动力学对称性模型

在含ＳＤＧ对的费米子动力学对称性模型的框架下，对原子核的十六极振动自由度给出了一种新的描述，并计算了元素１３２Ｔｅ的低激发能谱和Ｅ（２）跃迁几率计算结果表明，十六极振动自由度对原子核集体运动有重要的影响     

All-time Morse decompositions of linear nonautonomous dynamical systems

Morse decompositions provide inside information about the global asymptotic behavior of dynamical systems on compact metric spaces. Recently, the existence of Morse decompositions for nonautonomous dynamical systems was proved by restricting attention to the past or the future of the system, but in general, such a construction is not realizable for the entire time. In this article, it is shown that all-time Morse decompositions can be defined for linear systems on the projective space. Moreover, the dynamical properties are discussed and an analogue to the Theorem of Selgrade is proved.

     

Fluids with highly directional attractive forces. IV. Equilibrium polymerization

We investigate approximation methods for systems of molecules interacting by core repulsion and highly directional attraction due to several attraction sites. The force model chosen imitates a chemical bond by providing for bond saturation when binding occurs. The dense fluid is an equilibrium mixture ofs-mers with mutual repulsion. We use a previously derived reformulation of statistical thermodynamics, in which the particle species are monomeric units with a specified set of attraction sites bonded. Thermodynamic perturbation theory (TPT) and integral equations of two types are derived. The use of TPT is illustrated by explicit calculation for a molecular model with two attraction sites, capable of forming chain and ring polymers. Successes and defects of TPT are discussed. The integral equations for pair correlations between particles of specified bonding include calculation of self-consistent densities of species. Methods of calculating thermodynamic properties from the solutions of integral equations are given.Supported by the NSF under grant No. CHE-82-11236.     

Smash Products for Secondary Homotopy Groups

We construct a smash product operation on secondary homotopy groups yielding the structure of a lax symmetric monoidal functor. Applications on cup-one products, Toda brackets and Whitehead products are considered. The second author was partially supported by the Spanish Ministry of Education and Science under MEC-FEDER grants MTM2004-01865 and MTM2004-03629, the postdoctoral fellowship EX2004-0616, and a Juan de la Cierva research contract.     

Spectroscopic Study of Acid-base Equilibria and Ion Pairing in Supercritical Methanol

Acid-base equilibria between 2,5-dichlorophenol (DCP) and various bases (LiOH, NaOH, and KOH) were studied in ambient to supercritical methanol, by measuring the absorption spectrum of DCP at alkali metal hydroxide molalities ranging up to 10 mmol⋅kg⁻¹, at temperatures up to 250 °C and a pressure of 25.0 MPa. The spectrum was deconvoluted into contributions for the acidic (HA) and basic (A⁻) forms of DCP, taking into account a blue shift of the phenolate (A⁻) spectrum due to the effect of ion pairing with an alkali metal cation. Degrees of dissociation of DCP determined from the spectra suggested that the dissociation constant of DCP has a maximum around 150 °C, whereas that of KOH decreases with temperature. The phenolate-alkali metal ion pairing was examined from the peak shift of the phenolate spectrum in the presence of Li⁺, Na⁺, and K⁺. A smaller cation radius and higher temperature (thus a lower dielectric constant for methanol) give rise to stronger electrostatic interaction in the ion pair. The basicities of the alkali metal hydroxides in supercritical methanol were compared using DCP as an indicator, and were shown to follow the order LiOH < NaOH ≤ KOH. This order is the same as that for the catalytic effect of alkali metal hydroxides on the methylation of phenol in supercritical methanol (Takebayashi et al.: Ind. Eng. Chem. Res. 47:704–709, 2008). Electronic Supplementary Material  The online version of this article () contains supplementary material, which is available to authorized users.