XRD粉末衍射法研究微波场作用下4A分子筛的合成

在微波场作用下合成了粒度均匀、白度和钙离子交换容量高、性能优异的4A分子筛。用XRD粉末衍射法研究了硅铝比、水钠比、微波功率和微波加热时间对微波合成4A分子筛的影响,找出了在微波场作用下合成4A分子筛的最佳条件,并用IR, SEM和DSC等方法对合成的产物进行了表征。     

三氯化镨、三氯化钐与15-冠-5配合物的晶体结构

用X射线单晶衍射方法测定了PrCl₃·C₁₀H₂₀O₅和SmCl₁₃·C₁₀H₂₀O₅的晶体结构。二者均属单斜晶系,P2_1/c空间群。a=8.167(2)[8.129(7)],b=14.225(3)[14.176(7)],c=14.208(4)[14.117(5)]Å,β=104.78(2)[104.62(5)]°,Z=4。稀土离子的一侧与三个氯,另一侧与五个冠醚氧键合,形成不规则的八配位多面体。Ln-O平均键长为2.606[2.566]Å,Lu-Cl为2.714[2.666]Å,都比配位数高的相应键长短。     

三氯化钕异丙醇络合物的晶体结构和分子结构

本文报导了X射线衍射法确定的三氯化钕异丙醇络合物[NdCl₃·(CH₃CHOHCH₃)₃]₂的晶体结构。在晶体中每二个钕离子通过二个氯离子形成的氯桥相联,组成一个双核稀土络合物分子。其中每个Nd离子是七配位的。     

Ag掺杂P型ZnO薄膜及其同质结的光电性质

采用磁控溅射技术在Si基片上生长了Ag掺杂的ZnO薄膜,XRD测试表明所得薄膜结晶性质良好,未出现Ag的分相。未掺杂和Ag掺杂氧化锌薄膜的低温(10K)光致发光(PL)谱显示:Ag的掺入使得中性施主束缚激子发射(D0X)显著减弱,并且在3.315eV处观测到了与Ag有关的施主-受主对(DAP)发射,受主缺陷的形成归因于掺入的Ag替位Zn。计算得到受主能级离价带顶约110meV。霍尔效应测得电阻率约0.1Ω.cm,迁移率约36cm2/V.s,空穴浓度约1.7×1018cm-3。在此基础上制备了ZnO∶Ag/ZnO的同质结,I-V测试显示了明显的整流特性,且反向漏电流很小。所有结果表明Ag掺杂的氧化锌薄膜已经转化为p型。     

Effect of Annealing Temperature on Structural and Optical Properties of N-Doped ZnO Films

Nitrogen-doped ZnO （ZnO：N） films are prepared by thermal oxidation of sputtered Zn3N2 layers on A1203 substrates. The correlation between the structural and optical properties of ZnO：N films and annealing temperatures is investigated. X-ray diffraction result demonstrates that the as-sputtered Zn3N2 films are transformed into ZnO：N films after annealing above 600℃. X-ray photoelectron spectroscopy reveals that nitrogen has two chemical states in the ZnO：N films： the No acceptor and the double donor （N2）o. Due to the No acceptor, the hole concentration in the film annealed at 700℃ is predicted to be highest, which is also confirmed by Hall effect measurement. In addition, the temperature dependent photoluminescence spectra allow to calculate the nitrogen acceptor binding energy.     

In Situ Hydrothermal Synthesis of a Mononuclear Copper（Ⅱ） Complex： Cu（H2SIP-O）（bpy）（H2O） （H4SIP-O = 4-Hydroxyl-5-sulfoisophthalic Acid）

The mononuclear complex, Cu（H2SIP-O）（bpy）（H2O） （H4SIP-O = 4-hydroxyl- 5-sulfoisophthalic acid and bpy = 2,2＇-dipyridyl）, has been synthesized by the hydrothermal reaction of Cu（OH）2 with NaH2SIP and bpy at 160 ℃, and characterized by single-crystal X-ray diffraction, elemental analysis and IR spectrum. The new ligand 4-hydroxyl-5-sulfoisophthalic acid derived from 5-sulfoisophthalic acid ligand under an in situ hydrothermal condition. The crystal of the complex crystallizes in a triclinic system, space group P1, with a = 7.757（4）, b = 10.663（6）, c = 11.727（7）A, α = 94.272（4）, β = 104.067（7）, γ = 97.400（7）°, V= 927.4（9）A^3, Z = 2, C18H14N2O9SCu, Mr= 497.93, Dc= 1.783 g/cm^3,μ = 1.350 mm^-1, F（000） = 506, the final R = 0.0518 and wR = 0.1513 for 4180 observed reflections with I 〉 2σ（I）. The central Cu（II） ion is five-coordinated by two oxygen atoms from the H2SIP-O^2- ligand and two nitrogen atoms of bpy ligand in a distorted square-planar geometry as well as a water oxygen atom in the apical position to complete a distorted square-pyramidal coordination geometry. The mononuclear copper molecules are linked by hydrogen bonds between coordinated water molecules and sulfonate groups to form a one-dimensional double-chain structure. The chains are further held together through extensive π-π stacking interactions between the aromatic rings to form a three- dimensional supramolecular structure.     

《声学最新进展》即将出版

随着科学技术的发展,声学的应用日益广泛.为了推动声学研究和应用,促进声学技术交流,中国科学院声学研究所编辑了《声学最新进展》一书.书中收入了声学界著名学者和有关科技人员编写的十六篇反映声学各分支学科进展的综述和介绍美、苏、英、法、西德、日本、澳大利亚等国声学发展概况的文章.内容包     

劳厄点群及其在四圆衍射仪数据收集中的应用

晶体衍射强度是在倒易空间分布的。由于Friedel定律的作用,倒易空间中衍射的对称性属于11个Laue群。在晶体结构测定中,如果确定了劳厄群,不仅确定了晶系,而且为确定晶胞参数及收集数据的独立区提供了依据,同时也给确定空间群以至最后解出     

一氯·四(对甲氧基苯基)卟啉合锰(Ⅲ)的分子和晶体结构

氯代四(对甲氧苯基)卟啉合锰(Ⅲ)的晶体属于正交晶系,空间群为P_(bca)。晶胞参数:a=23.3973(6)A,b=22.5524(7)A,c=15.1043(2)A。V=7970.02A~3,Z:8。收集衍射强度在Nicolet XRD R3系列四圆衍射仪上进行。数据收集范围3°<2θ<45°,以ω扫描,用MoK_α射线,共收集到独立衍射点5200个,可观察点2859个(Ⅰ>3σ(Ⅰ))。重原子法测定结构,用方块矩阵最小二乘法修正结构参数,Mn-N的平均键长为2.005A,Mn-Cl的键长为2.370(3)A。     

三氟醋酸钆的晶体结构

测定了[Gd(CFCOO)_3·3H_2O]_2的晶体结构属单斜晶系,空间群为P2_1/c.Z=2.晶胞参数a=9.192(3),b=18.890(1),c=9.785(3);β=113.84(2)°.[Eu_(0.1)Gd_(0.9)(CF_3COO))3·3H_2O]_2的光谱构分析表明稀土离子周围的局部对称性可能是C_2(C_s)和C_2h。