Spanning network games

We study fundamental properties of monotone network enterprises which contain public vertices and have positive and negative costs on edges and vertices. Among the properties studied are the nonemptiness of the core, characterization of nonredundant core constraints, ease of computation of the core and the nucleolus, and cases of decomposition of the core and the nucleolus. Received December 1994/Final version March 1998     

The first self-assembled trimetallic lanthanide helicates driven by positive cooperativity

The segmental tris-tridentate ligand L7 reacts with stoichiometric quantities of Ln(III) (Ln=La-Lu) in acetonitrile to give the complexes [Ln(2)(L7)(3)](6+) and [Ln(3)(L7)(3)](9+). Formation constants point to negligible size-discriminating effects along the lanthanide series, but Scatchard plots suggest that the self-assembly of the trimetallic triple-stranded helicates [Ln(3)(L7)(3)](9+) is driven to completion by positive cooperativity, despite strong intermetallic electrostatic repulsions. Crystallization provides quantitatively [Ln(3)(L7)(3)](CF(3)SO(3))(9) (Ln=La, Eu, Gd, Tb, Lu) and the X-ray crystal structure of [Eu(3)(L7)(3)](CF(3)SO(3))(9).(CH(3)CN)(9).(H(2)O)(2) (Eu(3)C(216)H(226)N(48)O(35)F(27)S(9), triclinic, P1, Z=2) shows the three ligand strands wrapped around a pseudo-threefold axis defined by the three metal ions rigidly held at about 9 A. Each metal ion is coordinated by nine donor atoms in a pseudo-trigonal prismatic arrangement, but the existence of terminal carboxamide units in the ligand strands differentiates the electronic properties of the terminal and the central metallic sites. Photophysical data confirm that the three coordination sites possess comparable pseudo-trigonal symmetries in the solid state and in solution. High-resolution luminescence analyses evidence a low-lying LMCT state affecting the central EuN(9) site, so that multi-metal-centered luminescence is essentially dominated by the emission from the two terminal EuN(6)O(3) sites in [Eu(3)(L7)(3)](9+). New multicenter equations have been developed for investigating the solution structure of [Ln(3)(L7)(3)](9+) by paramagnetic NMR spectroscopy and linear correlations for Ln=Ce-Tb imply isostructurality for these larger lanthanides. NMR spectra point to the triple helical structure being maintained in solution, but an inversion of the magnitude of the second-rank crystal-field parameters, obtained by LIS analysis, for the LnN(6)O(3) and LnN(9) sites with respect to the parameters extracted for Eu(III) from luminescence data, suggests that the geometry of the central LnN(9) site is somewhat relaxed in solution.     

Shapley value for constant-sum games

It is proved that Youngs [4] axiomatization for the Shapley value by marginalism, efficiency, and symmetry is still valid for the Shapley value defined on the class of nonnegative constant-sum games with nonzero worth of grand coalition and on the entire class of constant-sum games as well.The research was supported by NWO (The Netherlands Organization for Scientific Research) grant NL-RF 047-008-010.I am thankful to Theo Driessen, Natalia Naumova and Elena Yanovskaya for interesting discussions and comments. The useful remarks of two anonymous referees are also appreciated.     

理化实验课的协同教学尝试

阐述了利用水果制作原电池进而测定电池的电动势和内阻的理化实验课的协同教学过程,并对教学效果进行了反馈.通过教学后思考总结了协同教学的优点,并对进一步实施提出了注意事项.     

一种求解合作博弈中成本分摊问题的方法

基于n人合作博弈的成本分摊模型，从二次费用分摊的角度提出了解此模型的一种方法，利用所有可能与i结成每一个联盟时的费用缺口的平均值来求βi，同时予以证明并举例说明。     

产学研合作教育创新人才培养

分析产学研合作教育培养创新型人才的优势以及与传统教育的主要区别，进行产学研合作教育几种模式的比较，通过在部分研究生和本科生中实施产学研合作教育的初步实践，探讨产学研合作教育对创新型人才培养的有效性。     

基于熵技术的供应商模糊分析评价方法和应用

建立了供应商选择评价指标体系；鉴于供应商评价所存在的模糊性和随机性，采用模糊分析法，结合信息论中的熵技术对供应商进行评价，避免了人为的主观性；最后给出了一个应用实例。     

合作学习在高职英语教学中的应用研究

新的高职英语教学大纲明确指出“倡导体验、实践、参与、合作与交流的学习方式,发展听、说、读、写、译的综合语言技能”。新一轮课程改革要求学生自主探索,主动获取,进行合作学习。通过在英语听、说、读、写、译等教学环节中的实践尝试,充分证明了合作学习在语言教学中的有效应用;合作学习不仅能突出学生的主体地位,关键是能够发挥学生的积极性,使课堂教学更有趣,使教学成效更明显。