两个具有相似{V10}狚阴离子骨架的化合物的合成和结构表征

本文描述了两个具有相似阴离子骨架的化合物,犤Na2(H2O)10(NH4)4犦犤V10O28犦(1)和犤Na2(H2O)10(NH4)4犦犤V9MoO28犦(2)。化合物1的阴离子是一个常见的钒十骨架,而化合物2与化合物1是同晶异质体,化合物2的阴离子是混有一个钼原子的钒十骨架。X-射线晶体结构测定表明,这两个化合物均属于三斜晶系,P1珔空间群。晶胞参数分别为化合物1:a=0.86024(4)nm,b=1.04561(5)nm,c=1.12828(4)nm,α=68.833(1)°,β=87.158(1)°,γ=67.065(1)°;化合物2:a=0.86511(3)nm,b=1.04549(5)nm,c=1.12446(5)nm,α=69.071(1)°,β=87.145(1)°,γ=66.982(1)°。     

Hydrothermal Synthesis and Crystal Structure of a New Sandwich—type Molybdenum Phosphate

1 INTRODUCTION The synthesis of porous and open-framework transition metal phosphates has received great in- terest due to their various compositions and topolo- gyies, as well as their useful properties such as con- trollable size- and shape-selectivity, rigid frame- works and chemical/thermal stability[1]. Of these phosphates constructed from oxometal polyhedra and PO4 tetrahedron, the most interesting is the [MoV6P4X31]n－ (X=O, OH) family with the dimen- sionalities ranging from …     

空气-氦-ICP 光源光谱分析性能的研究 Ⅲ ICP-D 型空气-氩-ICP光源最佳耦合度调整与光源稳定性

本文对 ICP-D 型 ICP 光源(保定电子设备厂)改装为 ICP-D 型空气-氩-ICP(及 Ar-ICP两用)光源的最佳耦合度及光源稳定性进行了细致地研究,数据表明改装后的光源其可调性及稳定性均较满意,可与 Ar-ICP 相比。     

A Novel Hybrid Solid Constructed from Tetramolybdate and Copper Complexes with Mixed Ligands: [{(Cu·phen)_2(tp)}{(Cu·phen·H_2O)_2(tp)}{Mo_4O_(14)}]

A novel copper molybdate with mixed ligands, [{(Cu·phen)2(tp)}{(Cu·phen·H2O)2(tp)}{Mo4O14}] (phen = 1,10-phenanthroline, tp = terephthalate) 1, has been hydrothermally synthesized and structurally characterized. The crystal belongs to monoclinic system, space group P21/c with a = 13.1711(7), b = 19.6132(10), c = 13.6910(7) , β = 117.6870(10)°, V = 3131.8(3) 3, Z = 2, C64H44Cu4Mo4N8O24, Mr = 1946.99, Dc = 2.065 g/cm3, F(000) = 1920, μ(MoKα) = 2.198 mm-1, R = 0.0810 and wR = 0.2012 for 4233 observed reflections (I > 2σ(I)). The structural analysis indicates that the title compound contains a discrete tetramolybdate cluster decorated with copper complex fragments and tp ligands bridging the clusters into a wave-like layer. The hydrogen bond- ing between adjacent layers further extends the compound into a 3-D framework.     

天津广电VPN平台设计与建设

1项目建设背景随着逐步落实高丽书记"保增长、渡难关、上水平"的讲话精神,天津正在大力推进信息化建设的步伐。各政务系统的电子化、网络化、政务信息的公开化对网络,以及全市各类企业的信息化发展都对作为基础的网络提出了更高速率、更高安全性、可靠性的要求。作为党的信息传播重要阵地的天津广播电视网     

pH控制下3，5-二羧基苯氧乙酸-Cd(Ⅱ)配合物的合成及晶体结构

以3,5-二羧基苯氧乙酸(H3L)为配体与醋酸镉在不同pH条件下获得了2个Cd(Ⅱ)配合物[Cd(H2L)2(H2O)4](1)、[Cd(HL)]n(2),通过红外、X-射线单晶衍射等检测手段对所合成的化合物进行了结构表征。测定结果表明,这2个配合物分别为配位分子和三维配位聚合物,其结构的形成与水热条件的pH值密切相关。该结果对以pH值控制配合物结构提供了研究基础。     

A New Luminescent Complex Cd（Ⅱ）-xanthene-9-carboxylate: [Cd（L）2（H2O）]n

A new luminescent Cd(Ⅱ) coordination polymer, [Cd(L)2(H2O)]n 1 (HL = xan-thene-9-carboxylic acid), was synthesized hydrothermally and characterized by satisfactory elemental analysis, FT-IR spectra and single-crystal X-ray diffraction. The crystal is of orthorhombic system, space group P212121 with a = 6.4548(4), b = 13.0876(12), c = 27.466(2), V = 2320.3(3)3, C28H20CdO7, Mr = 580.84, Z = 4, Dc = 1.663 g/cm3, F(000) = 1168, μ = 0.990 mm-1, Flack parameter = 0.00(2), the final R = 0.0296 and wR = 0.0691 for 5301 observed reflections (I > 2σ(I)). 1 features a one-dimensional (1D) carboxylate oxygen-bridged inorganic chain, which is further connected by intermolecular hydrogen bonds into a three-dimensional (3D) framework. Moreover, compound 1 exhibits strong photoluminescence in the solid state at room temperature.     

激光诱导击穿光谱技术定量分析SF_6中的痕量O

六氟化硫(SF_6)气体因其优良的绝缘和灭弧性能,被广泛应用于高压绝缘设备中。然而,当存在H_2O和O_2等杂质时,SF_6气体在局部放电等作用下分解成的低氟化物会进一步与杂质发生反应生成稳定的氟硫氧化物和氢化物,使得设备绝缘性能下降,危害电网安全,因此检测和分析SF_6中微水、微氧及其分解产物具有重要意义。采用激光诱导击穿光谱技术测量了SF_6中的痕量O含量。利用CaF2作为窗口材料,解决了窗口材料在不断腐蚀作用下引起的激发能量逐渐衰减以及窗口材料与SF_6气体击穿产物反应引入的污染影响测量结果的问题,消除了由激发条件改变引起的等离子体状态的变化;通过测量不同O含量的SF_6气体激光诱导击穿光谱,结合迭代小波分析对实测光谱进行基线校正和降噪处理,通过定标曲线获得了O元素检测限为38ppm。利用偏最小二乘法建立了稳定的定量分析模型,改善了定量分析模型的稳定性和精度。     

谈建构主义理论与中学化学教学

建构主义是当代最为流行的学习理论,它为教师反思教学行为提供了一个全新的视角。本文介绍了建构主义的基本观点和主要教学模式,提出了在化学教学中促进学生意义建构的指导思想和具体做法。     

Syntheses and Crystal Structures of two Ring—like {Mo18}Cluster Compounds

1INTRODUCTIONThepolyoxomolybdateshavebeenwidelyresearchedinmanyfieldssuchascatalysis,biology,medicineandmaterialsciencebecauseoftheirrichphysicalandchemicalproperties[1].Thoughmanypolyoxomolybdateshavebeenreported[2],furtherresearchisstillnecessaryforthestudyof搑eduction-oxidation-reconstitution?self-assemblyprocesses[3,4].Polyoxomolybdatesarenormallybuiltupundersuitableconditionsbyafewbuildingblockssuchas{Mo2},{Mo8}and{Mo9}inself-assemblyway[5,6].The{Mo18}clustershaveseveralstructuralty…