Hydrothermal Synthesis and Crystal Structure of a Keggin Polyoxometalate [Co^Ⅱ（2,2′-bipy）2（H2O）]2[SiW^Ⅵ12O40]·2H2O

A Keggin-type tungstosilicate compound [Co^Ⅱ（2,2′-bipy）2（H2O）]2[SiW^Ⅵ12O40]·2H2O 1 （bipy = bipyridine） was prepared by a hydrothermal method for the first time. Single-crystal X-ray diffraction revealed that 1 （C40H40Co2N8O44SiW12） crystallizes in the triclinic system, space group P1 with a = 10.4979（6）, b = 13.3946（7）, c = 13.5756（8）A, α= 70.0769（18）, β = 68.910（3）, γ = 74.186（4）°, V = 1649.84（16）A^3, Mr = 3688.95, Z = 1, Dc = 3.713 mg·m^-3, μ = 21.432 mm^-1, F（000） = 1644, S = 1.058, the final R = 0.0511 and wR =0.1023 for 6523 observed reflections （I 〉 2σ（I））. Compound 1 consists of two coordinated cation fragments [Co^Ⅱ（2,2′-bipy）2（H2O）]^2＋, one normal Keggin polyanion unit [SiW^Ⅵ12O40]^4- and two lattice water molecules. To be noted, each polyanion unit is linked to two cation fragments by its two surface terminal oxygen atoms and two cobalt atoms of two cation fragments forming an organic-inorganic hybrid unit in 1. Furthermore, the compound shows strong photoluminescence property in the solid state at room temperature.     

Two Nickel(Ⅱ) Complexes Constructed by Novel Bis(3-methoxy-2-pyridyl)ether-6,6"-dicarboxylic Acid Ligand: Lattice Water Control of Structure

Under given conditions, two complexes of [Ni(H2O)2BEDA]·2H2O 1 and [Ni(Py)2-sized and characterized by elemental analysis and X-ray single-crystal diffraction. Crystal data for 1:C14H18NiN2O11, monoclinic C2/c, a = 14.3844(17), b = 12.9900(15), c = 9.6309(11) (A°),β=104.3350(10)°, V = 1743.5(4) (A°)3, Z = 4, Dc= 1.711 g/cm3, F(000) = 928,μ= 1.179 mm-1, Mr=449.01, the final R = 0.0228 and wR = 0.0625. Crystal data for 2: C24H32NiN4O13, triclinic P1, a=9.423(2), b = 11.863(3), c = 13.089(3) (A°), α = 91.511(3), β= 92.465(3), γ = 100.696(2)°, V =1435.6(6) (A°)3, Z = 2, Dc= 1.488 g/cm3, F(000) = 672,μ= 0.748 mm-1, M,= 643.25, the final R =0.0400 and wR = 0.0975. Interestingly, in the two complexes, lattice water molecules dominate its crystal structures. Therefore, extensive intermolecular hydrogen bonds assemble 1 and 2 into 2D extended sheets and a 3D open framework, respectively. Furthermore, water molecules present in 2 are associated to form water clusters.     

Hydrothermal Synthesis and Crystal Structure of a Keggin Polyoxometalate [CoⅡ(2,2'-bipy)2(H2O)]2[SiWVI12O40]·2H2O

A Keggin-type tungstosilicate compound [CoII(2,2'-bipy)2(H2O)]2[SiWVI12O40]·2H2O1 (bipy = bipyridine) was prepared by a hydrothermal method for the first time. Single-crystal X-ray diffraction revealed that 1 (C4H40Co2N8O44SiW12) crystallizes in the triclinic system, space group P1 with a = 10.4979(6), b = 13.3946(7), c = 13.5756(8) (A°), α= 70.0769(18), β= 68.910(3), y = 74.186(4)°,V =1649.84(16) (A°)3, M, = 3688.95, Z =1, Dc= 3.713 mg.m-3,μ= 21.432 mm-1, F(000) = 1644, S =1.058, the final R = 0.0511 and wR = 0.1023 for 6523 observed reflections (I> 2σ(I)). Compound 1 consists of two coordinated cation fragments [CoII(2,2'-bipy)2(H2O)]2+, one normal Keggin polyanion unit [SiWVI12O40]4- and two lattice water molecules. To be noted, each polyanion unit is linked to two cation fragments by its two surface terminal oxygen atoms and two cobalt atoms of two cation fragments forming an organic-inorganic hybrid unit in 1. Furthermore, the compound shows strong photo-luminescence property in the solid state at room temperature.     

不同构型聚丙烯的玻璃化转变温度的分子模拟

应用分子力学和分子动力学的方法对3种不同构型聚丙烯高分子的玻璃化转变温度进行了模拟.用NPT(等温等压)分子动力学模拟获得聚丙烯(PP)在不同温度下的特征体积,通过对模拟得到的V-T做图,求得玻璃化转变温度,其结果与实验值吻合较好.并分析了聚丙烯主链柔顺性和立构规整度对高分子玻璃化转变的影响.     

电感耦合等离子体原子发射光谱法测定柑橘中镧系元素含量

应用电感耦合等离子体发射光谱法同时测定柑橘中的5种稀土元素镧、铈、镨、钕和钐.对分析线选择、积分时问的选择、消解方法的选择、介质的影响等进行了试验.与干灰化法相比较,微波消解法处理样品所得结果的准确度和精密度更好.选择波长为333.749,418.660,390.844,415.608及359.260 nm 5条谱线依次作为测定镧、铈、镨、钕和钐的分析线,测得5种稀土元素的检出限(3s/k)依次为0.003 3,0.017 0,0.014 0,0.039 0及0.007 8 mg·L-1.应用此法测定了沙田柚中5种稀土元素的含量,回收率在96.8%～101.0%之间,相对标准偏差(n=5)小于5.5%.与GB/T 5009.94-2003法比较,经t检验,在置信水平α=0.05时,测定沙田柚时两种方法无显著性差异.     

用"一锅法"合成取代吲哚衍生物

利用取代苯肼盐酸盐与丙酮酸、1,3-二苯基-1,3-丙二酮反应合成了3种取代吲哚衍生物.采用"一锅法"对酯化反应进行了改进,以盐酸酸化的乙醇作溶剂,苯磺酸催化,一步得到取代的吲哚酸酯.本文对吲哚环化的反应机理、合成条件进行了探讨,发现反应温度不同所得产物也不同.合成产物用IR, 1H NMR和MS进行了分析表征.     

Deep Web中基于关联规则的整体模式匹配

不同于Surface Web的信息获取方式,Deep Web中用户需通过查询接口才能得到其中的数据.查询接口一般形成属性间复杂的m∶n匹配.为统一相同领域的查询接口,提出了一种基于关联规则的匹配方法,从整体上双重匹配成组属性和同义属性,很好地实现了同一领域中查询接口的整合问题.特别对于大量的数据源时,无论是准确率还是效率都比传统的方法有很大的提高.     

论马克思的人文关怀思想

在马克思的全部思想中,洋溢着博大深刻的人文关怀思想,马克思通过研究伊壁鸠鲁的原子学说,张扬了“自由、平等”的思想,体现出了人文关怀的价值倾向;通过对“异化劳动”和人的本质的异化的批判,显示了对人的问题的真正关注,表现出切实的人文关怀;通过创立科学共产主义学说,把建立“以每个人的全面而自由的发展为基本原则的社会形式”作为人文关怀的终极目标。     

遗传算法在水污染控制系统规划研究中的应用

将遗传算法应用于以汾河太原城区段南内环桥至小店桥为研究对象的水污染控制系统规划研究,将遗传算法在水污染控制系统规划研究中具体化,其应用结果较为满意.结果表明该算法对目标函数的形式与性质要求较低,可在全局范围内搜索并快速收敛,实现了水污染控制系统规划模型最优求解,且编程简单,易于将计算机技术应用其中.     

对高校专业教学团队的思考

专业教学是全面提高高校教学质量的核心内容,建立专业教学团队有利于专业教学水平和教学质量的提高.研究了专业教学团队和教学知识产生之间的关系,提出了专业教学团队建设的一些建议.