双核钯配合物［Ph_2P（o－C_6H_4CO）PdCl］_2·2CH_2Cl_

合成了双氯桥双核钯配合物［Ｐｈ_２Ｐ（ｏ－Ｃ_６Ｈ_４ＣＯ）ＰｄＣｌ］_２·２ＣＨ_２Ｃｌ_２进行了元素分析、红外光谱表征和晶体结构测定，研究了其催化氢化性能。在３０～８０℃、氢分压１．０～５．０ＭＰａ的范围内。发现该配合物是催化氢化丙烯酸为丙酸的有效催化剂．晶体［Ｐｄ_２Ｃｌ_２（Ｃ_（１９）Ｈ_（１４）ＯＰ）_２］·２ＣＨ_２Ｃｌ_２属Ｐ１空间群，ａ＝０．９３０４（３）ｎｍ，ｂ＝１．０３９２（２）ｎｍ，ｃ＝１．１０６２（３）ｎｍ；ａ＝１０２．７８（２），Ｂ＝９７．３５（３），γ＝９５．２５（２），Ｖ＝１．０２６４ｎｍ~３，Ｍ＝１０３２．１７，２＝１，Ｄｃ＝１．６７０ｇ／ｃｍ~３，ｕ＝１３．６９５ｃｍ~（－１），Ｆ（０００）＝５１２，用１９４５个独立衍射精修结构，最终Ｒ＝０．０３６。     

汽车制造商分时租赁模式采用及产品线策略研究

考虑自有平台和第三方平台两种分时租赁方式,将汽车质量划分为性能质量和环境质量,构建销售模式、纯分时租赁模式和混合模式下的产品线策略模型,研究制造商产品线策略与商业模式之间的相互作用。研究发现,同品牌产品间竞争和合并效应是分时租赁模式影响产品线策略的两个关键因素。同品牌产品间竞争的加剧和合并效应的增大都会激励企业选择性能更好的车型而忽略其环境表现。分时租赁模式能同时改进利润与产品环境表现,但存在条件:当消费者价格敏感性较低时,使用成本高且合并效应小是实现同时改进的条件;当消费者价格敏感较高时,使用成本低且合并效应小则是同时改进的条件。     

On bandwidth sums of graphs

ＯＮＢＡＮＤＷＩＤＴＨＳＵＭＳＯＦＧＲＡＰＨＳＹＡＯＢＩＮＧ（姚兵）;ＷＡＮＧＪＩＡＮＦＡＮＧ（王建方）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ,ＮｏｒｉｈｗｅｓｔｅｔｅｒｎＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ,Ｌａｎｚｈｏｕ７３００７０,Ｃｈｉ...     

Hamiltonian cycles in 1-tough graphs

For a graphG, let ₃ = min{ _i=1 ³ d(u_i): {u₁, u₂, u₃} is an independent set ofG} and = min{ _i=1 ³ d(u_i) – is an independent set ofG}. In this paper, we shall prove the following result: LetG be a 1-tough graph withn vertices such that ₃ n and – 4. ThenG is hamiltonian. This generalizes a result of Fassbender [2], a result of Flandrin, Jung and Li [3] and a result of Jung [5].Supported in part by das promotionsstipendium nach dem NaFöG and the Post-Doctoral Foundation of China.     

A NEW PROBE FOR IDENTIFYING PROPERTIES OF SUPPORTED METAL AND METAL OXIDE CATALYSTS

A novel molecular probe for identifying properties of supported transitionmetals and metal oxides catalysts was established.The catalytic mechanism oftransition metals was proposed.     

GABAA五种亚型受体与BZ配基的3D-QSAR研究

GABAA受体是中枢神经系统内重要的抑制性受体,有广泛的神经生理活性.由于镇静/抗惊厥药物在临床上的广泛应用,使得其中苯并二氮杂作用位点尤为重要.我们用比较分子场法(CoMFA)对一系列咪唑苯并二氮杂类化合物（BZ）与五种重组受体亚型的亲和力进行了结构活性关系研究,得到的一组模型都有较高的交叉验证系数.并在此基础上,建立了非交叉验证的一组PLS模型.用该组模型对随机选择的6个化合物组成的测试集进行了预测,都得到了相当满意的结果,表明所建立的一组模型具有良好的预测能力.本研究对于设计高亲和力的BZ受体的配基和研究GABAA受体的模型有指导意义.     

Pose scoring by NMR

Recently, we have developed a fast approach to calculate NMR chemical shifts using the divide and conquer method at the semiempirical level. To demonstrate the utility of this approach for characterizing protein-ligand interactions, we used the deviation of calculated chemical shift perturbations from experiment to determine the orientation of a ligand (GPI-1046) in the binding pocket of the FK506 binding protein (FKBP12). Moreover, we were able to select the native state of the ligand from a collection of decoy poses. A key hydrogen bond between O1 and HN in Ile56 was also identified. Our results suggest that ligand-induced chemical shift perturbations can be used to refine protein/ligand structures.     

The study of terbium generated bacterirhodopsin

The localization of Terbium (Tb³⁺) cations binding to deionized bacteriorhodopsin (bR) has been studied by using spectroscopic methods. It was found that adding Tb³⁺ cations to deionized bR affects the fluorescence lifetimes of tryptophan (Trp) in bR, the wavelength of fluorescence peak shifts “blue” and the peak value of fluorescence decreases. It was also found that adding one Tb³⁺ cation to deionized bR can restore the purple state from its blue state obviously. The measurements of absorbance, fluorescence and lifetime of fluorescence also show that when more than three Tb³⁺ cations are added, no further changes can be found. It is suggested that one Tb³⁺ specific binding site for the color-controlling is located on the exterior of the bR trimer structure to negatively charged lipids near Trp-10 and Trp-12. Three Tb³⁺ cations binding per bR is needed for the regenerated bR.     

Effect of Co-solvent on the Palladium Catalyzed Alkoxycarbonylation of Allyl Bromide in Supercritical CO_2

We have studied the palladium-catalyzed alkoxycarbonylation of allyl bromide in supercritical (sc) CO2 and found the reaction rate in sc CO2 was lower than those in some organic solvents1. The possible reason was the lower solubility of sc CO2 for the palladium catalyst. As an effective approach to improve the solubility of varieties of solutes, cosolvent such as ethanol has been widely used in the sc CO2 extraction2,3. Based on the above consideration, we chose several organic reagents…     

混合溶剂对磺化聚苯乙烯水基微乳液体系形态的影响

利用相反转技术制备磺化聚苯乙烯(SPS)水基微乳液,研究发现,通过选择溶剂和控制混合溶剂的组成,可制备不同颗粒形态结构的SPS水基微乳液,并研究了相反转过程、乳液稳定性与混合溶剂组成之间的关系。