本刊英文版Vol.30(2014),No.5论文摘要（英文）

<正>Similarity Degrees for the Crossed Product of yon Neumann Algebras Jin Song WU Wen Ming WU Abstract In this paper,we will estimate an upper bound for the similarity degree of the crossed product of a hyperfinite finite yon Neumann algebra by weakly compact action of an infinite discrete group.We will also improve some upper bounds for similarity degrees of some finite von Neumann algebras.     

Partial Crossed Products and Goldie Rings

In this paper we consider the transfer of the property of being a left Goldie ring between a ring A and its partial crossed product A*_α G by a twisted partial action α of a group G on A.     

On corepresentations of multiplier Hopf algebras

We present a general construction producing a unitary corepresentation of a multiplier Hopf algebra in itself and study RR-corepresentations of twisted tensor coproduct multiplier Hopf algebra. Then we investigate some properties of functors, integrals and morphisms related to the categories of the crossed modules and covariant modules over multiplier Hopf algebras. By doing so, we can apply our theory to the case of group-cograded multiplier Hopf algebras, in particular, the case of Hopf group-coalgebras.     

Angle-resolved photoelectron spectroscopy of randomly oriented 3-hydroxytetrahydrofuran enantiomers.

Circular dichroism in the angular distribution of valence photoelectrons emitted from randomly oriented 3-hydroxytetrahydrofuran enantiomers (ThS and ThR) has been observed in gas-phase experiments using circularly polarized vacuum ultraviolet (VUV) light. The measured dichroism for both ThS and ThR, acquired at the single magic angle theta=234.73 degrees and at photon energies of 22, 19, 16, and 14 eV, points to an asymmetric forward-backward scattering of the photoelectrons from their highest occupied molecular orbitals (HOMO) HOMO-1 and HOMO-2, of up to 5%, depending on the photon energy. The asymmetry reverses on exchange of either the helicity of the radiation or the configuration of Th. The photoionization dichroic D parameters of ThS and ThR have been measured and their values discussed in the light of LCAO B-spline density functional theory (DFT) predictions. While an acceptable agreement is found between the dichroic parameter measured and calculated at the highest photon energy for the HOMO and HOMO-2 orbitals of Th, a significant discrepancy is observed for the HOMO-1 state which is attributed to the floppiness of Th, in particular to the comparatively large sensitivity of the size and shape of its HOMO-1 on nuclear vibrational motion.     

NONLINEAR OPTICAL PROPERTIES OF X-TYPE CHROMOPHORES AND THEIR DOPED FILMS

Two X-type chromophores, 2-[4-(4,5-di(4-nitrophenyl) imidazolyl) phenyl]-4,5-di(4-methoxyphenyl)-imidazole (DNPIPDMOPI), 2-[4-(4,5-di(4-nitrophenyl)-imidazolyl) phenyl]-4,5-di(4-aminophenyl)-imidazole (DNPIPDAPI), were synthesized and characterized. The results show that they possess good nonlinearity, considerable blue-shifted absorption (385 nm and 379 nm in THF) and high decomposition temperature (377℃ and 405℃). These mean that the X-type chromophores possess a rather good nonlinearity-transparency-thermal stability trade-off. The multi-step corona-poling technique at elevated temperature and in-situ SHG measurements were used to obtain and evaluate the poled films of these chromophores doped in PMMA. The largest SHG signals appeared at 110-120℃, which are 12.5 pm/V and 16.7 pm/V respectively. The dependence of poling induced orientation stability on temperature was measured by depoling experiments and the results indicate that the poling-induced orientation of the films is stable at about 100℃. Theoretic analyses imply that better orientation stability arises from the X-type structure of chromophore. The X-type chromophore has two crossed intramolecular CT, both βxxx and βxyy can contribute to the second-order susceptibility, and the ratio of the tensorial components (γ = βxyy/βxxx) is about 1/3, so the orientation decay of the films induced by rising temperature will provide a certain compensation for the contribution of βxyy of chromophores.     

绝对损失下双边截断型分布族参数的渐近最优经验Bayes估计

本文在绝对损失下构造了双边截断型分布族参数的经验Bayes估计,并在合适的条件下证明了该估计的渐近最优性.最后,给出两个有关本文主要结果的例子.     

Hopf代数的双交叉积

本文定义并详细讨论了交叉余积，考虑交叉积与交叉余积合起未成为双代数的问题，讨论了由内作用，内余作用构造的双交叉积．我们还用正合序列刻划了双交叉积．     

Monotonicity and Consistency in Matching Markets

Objective: To obtain axiomatic characterizations of the core of one-to-one and one-to-many matching markets. Methods: The axioms recently applied to characterize the core of assignment games were adapted to the models of this paper. Results: The core of one-to-one matching markets is characterized by two different lists of axioms. The first one consists of weak unanimity, population monotonicity, and Maskin monotonicity. The second consists of weak unanimity, population monotonicity, and consistency. If we allow for weak preferences, the core is characterized by weak unanimity, population monotonicity, Maskin monotonicity, and consistency. For one-to-many matchings, the same lists as for the case of strict preferences characterize the core. Conclusions: The cores of the discrete matching markets are characterized by axioms that almost overlap with the axioms characterizing the core of the continuous matching markets. This provides an axiomatic explanation for the observations in the literature that almost parallel properties are obtained for the core of the two models. We observe that Maskin monotonicity is closely related to consistency in matching marketsThis research is financially supported by Waseda University Grant for Special Research Projects #2000A−887, 21COE-GLOPE, and Grant-in-Aid for Scientific Research #15530125, JSPS. This paper was presented at the 7th. International Meeting of the Society for Social Choice and Welfare held in Osaka, Japan. The comments of the participants are gratefully acknowledged. The author thanks Professors William Thomson, Eiichi Miyagawa and anonymous referees for their valuable comments and suggestions. Any remaining errors are independent     

阶数不超过4的交叉超立方体是点可迁的

P Kulasinghe and S Bettayeb showed that any multiply-twisted hypercube with five or more dimensions is not vertex-transitive. This note shows that any multiply-twisted hypercube with four or less dimensions is vertex-transitive, and that any multiply-twisted hypercube with three or larger dimensions is not edge-transitive.