锗的应用与市场分析

分析了锗产量增长速度不快的原因和当前应用领域现状。并根据锗的性质，对锗市场作了分析，提出了扩大锗应用的看法。     

高含量锗物料中锗的滴定法测定

从碘酸钾容量法测定高含量锗物料中锗量的关键步骤蒸馏分离入手,分析了方法误差的原因,推出了一套设计合理、无泄漏、易于操作的蒸馏装置,使用该蒸馏装置蒸馏分离效果好,标准回收率高,测定结果精密高,具有推广价值。     

硅锗酞菁聚合物的电子结构

在自洽场晶体轨道法全略微分重叠(SCFCNDO/2－CO)水平上对氧桥和硫桥一维链硅锗酞菁聚合物的能带结构和电子特性进行了研究,探讨了堆积酞菁环间交错角以及中心原子和桥原子的变化对电子特性的影响.计算结果表明,除前线带宽外,交错角变化对所研究的聚酞菁电子特性影响不大.晶体轨道分析表明,氧桥聚酞菁电荷载流子主要通过垂直酞菁环π轨道的纵向重叠导电通路流动,而硫桥聚酞菁导带电子还可经中心原子和桥原子的d轨道重叠通路迁移.     

硅锗分子筛的结构稳固、结构可控调变及催化应用

硅锗分子筛因其超大的孔道结构, 在大分子催化反应领域具有潜在的应用前景. 硅锗分子筛骨架的富锗双四元环结构单元的不稳定性虽然限制了它们的实际应用, 但却为结构后处理修饰以构建新晶体结构分子筛提供了可能. 本文介绍了硅锗分子筛结构稳固、 结构可控调变和催化应用3个方面的研究进展, 并展望了其未来的发展方向和挑战.     

富锗红栓菌锗多糖的研究

通过生物工程技术，自行筛选的富锗红栓菌经发酵培养，有机锗与菌体内的多糖结合，再经分离纯化获得高活性生物调节剂－锗多糖，并研究了锗多糖的理化特性与结构。     

微量元素锗的研究进展

综述了国内外在猪的生物学效应及保健作用方面的研究现状，表明锗具有抗菌消炎，治疗肿瘤，参与免疫调节反应的功效。     

微量元素锗的药理作用研究进展

近年来对微量元素锗的研究日益深入，它的药理作用愈来愈受到人们的重视。本文就其研究中的进展及抗肿瘤方面的不同观点作一概述。     

锗的分析概况

本文是关于锗分析方法的综述，共分锗的分析和分离方法，锗的定量法和有机锗Ｇｅ－１３２产量质量控制法研究现状三大部分。锗的分析和分离方法中，介绍了锗的分析方法及分类，锗样品前处理、分离与预浓集的原理和方法，并便 出了有参考价值的图表，锗的定量法中介绍了重量法、容量法、分光光度法、荧光法和发光分析法原子吸收分光光度法、原子发射光法、电化学分析法。每一分析法中又介绍了测定法研究及应用实例。在测定法研究及应     

锗分析方法的研究进展

对2000～2008年间有关锗分析方法的研究进展作了综述。内容包括滴定法、分光光度法、荧光光谱法、原子荧光光谱法、原子吸收光谱法、电感耦合等离子体原子发射光谱法、电感耦合等离子体质谱法和电化学法等,指出了各分析方法的特点和不足,展望了这些分析方法在锗分析中的应用前景(引用文献65篇)。     

光通讯波段聚合物光波导材料的研究进展

光学聚合物由于其在光通讯领域的集成光电器件与光互连应用方面有经济和实用价值而备受关注。本文介绍了光通讯波段有机聚合物光波导材料的特点和研究进展。     

马铃薯膳食纤维的结构特征分析

用水蒸汽爆破和氧化法对马铃薯废渣(PR)进行处理,制备马铃薯膳食纤维(PDF),并用红外光谱法、扫描电镜、热重及化学分析等方法对膳食纤维进行表征。结果表明,经过一系列的物理与化学处理,马铃薯渣中的半乳聚糖在蒸汽爆破下由长链断成短链,且由原来的块状变成片状、无规则的空间网层结构,断链的半乳糖醛基在氧化作用下生成羧基;所得到的PDF具有比表面积大、热力学稳定等特点。研究了PDF对胆固醇吸附性能。结果表明PDF对胆固醇的吸附量为1.4mg/g左右,其吸附机理符合Freundlich模式。马铃薯膳食纤维在生物体内对致病物质有一定的吸附作用。     

Oxidative Coupling of Ge94‐ Zintl Anions ‐ Hexagonal Rod Packing of Linear [Ge9=Ge9=Ge9=Ge9]8‐

The compound [K(18‐crown‐6)]₈[Ge₉=Ge₉=Ge₉=Ge₉] ˙ 8en ( 1 ) featuring a [Ge₉=Ge₉=Ge₉=Ge₉]^8‐cluster anion was synthesized from K₄Ge₉ for the first time. The X‐ray single crystal analysis shows that, in many respects such as bond connection and packing style, compound 1 is quite different from the previously reported compounds [Rb(18‐crown‐6)]₈[Ge₉=Ge₉=Ge₉=Ge₉] ˙ 2en ( 2 ) and [Rb(18‐crown‐6)]₈[Ge₉=Ge₉=Ge₉=Ge₉] ˙ 6en ( 3 ). Crystal packing of 1 gives strong indications that the highly charged nano‐rods self assembly in a hexagonal rod packing.     

Na12Ge17: A Compound with the Zintl Anions [Ge4]4— and [Ge9]4— — Synthesis,Crystal Structure,and Raman Spectrum

Na₁₂Ge₁₇ is prepared from the elements at 1025 K in sealed niobium ampoules. The crystal structure reinvestigation reveals a doubling of the unit cell (space group:P2₁/c; a = 22.117(3)Å, b = 12.803(3)Å, c = 41.557(6)Å, β = 91.31(2)°, Z = 16; Pearson code: mP464), furthermore, weak superstructure reflections indicate an even larger C‐centred monoclinic cell. The characteristic structural units are the isolated cluster anions [Ge₉]^4— and [Ge₄]^4— in ratio 1:2, respectively. The crystal structure represents a hierarchical cluster replacement structure of the hexagonal Laves phase MgZn₂ in which the Mg and Zn atoms are replaced by the Ge₉ and Ge₄ units, respectively. The Raman spectrum of Na₁₂Ge₁₇ exhibits the characteristic breathing modes of the constituent cluster anions at ν = 274 cm^—1 ([Ge₉]^4—) and ν = 222 cm^—1 ([Ge₄]^4—) which may be used for identification of these clusters in solid phases and in solutions. Raman spectra further prove that Na₁₂Ge₁₇ is partial soluble both in ethylenediamine and liquid ammonia. The solution and the solid extract contain solely [Ge₉]^4—. The remaining insoluble residue is Na₄Ge₄. By heating the solvate Na₄Ge₉(NH₃)_n releases NH₃ and decomposes irreversibly at 742 K, yielding Na₁₂Ge₁₇ and Ge.     

线性脂环族聚酰胺化学结构对其力学和光学性能的影响

以重复单元结构不同的3种线性脂环族聚酰胺(LATPA)材料为研究对象,通过核磁共振谱、红外光谱、热分析、X射线衍射等技术,研究了链结构单元的侧基、端基对材料聚集态结构的影响,并对比研究了不同聚集态结构材料的宏观力学性能和光学透明性差异,建立了链结构、聚集态结构与力学性能、光学性能的关系.研究发现,侧基带来的大空间位阻降...     

An Optical Fibre Probe for the Determination of Glucose Based on Immobilized Glucose Dehydrogenase

Abstract

An optical fibre probe based on glucose dehydrogenase immobilized on nylon was constructed. The probe was used to quantitate glucose through a measurement of the fluorescence of the NADH formed by the enzyme-catalyzed reduction of glucose in the presence of NAD. The probe response was reproducible and displayed good linearity in the concentration range of 1.1 to 11.0 mM glucose. The limit of detection was 0.6 mM glucose. The response was affected by pH and NAD concentration.     

Y-Cu共掺杂ZnO电子结构与光学性质的第一性原理计算

采用基于密度泛函理论(DFT)的第一性原理平面波赝势法研究了本征ZnO、Y和Cu单掺杂ZnO、Y-Cu共掺杂ZnO的电子结构和光学性质. 计算结果表明, 在本文的掺杂浓度下, Y和Cu单掺杂可以提高ZnO的载流子浓度, 从而改善ZnO的导电性, Y-Cu共掺时ZnO半导体进入简并状态, 呈现金属性. Y 掺杂ZnO可以提高体系在紫外区域的吸收, 而Cu掺杂ZnO在可见光和近紫外区域发生吸收增强现象, 其中由于Y离子和Cu离子之间的协同效应, Y-Cu共掺杂ZnO时体系对可见光和近紫外区域的光子能量吸收大幅增加, 因此Y-Cu共掺杂ZnO可以用于制作光电感应器件.     

Synthesis,Crystal and Electronic Structure,and Optical Property of the Quaternary Selenide: La3Sb0.33SiSe7

The quaternary selenide, La₃Sb_0.33SiSe₇, was prepared from stoichiometric mixtures of elements by solid‐state reactions at 1223 K in an evacuated silica tube. La₃Sb_0.33SiSe₇ crystallizes in the chiral P6₃ space group and belongs to the Ce₃Al_1.67S₇ structure type. Its structure features one‐dimensional chains of face‐sharing SbSe₆ octahedra running parallel to the c direction surrounded by the discrete SiSe₄ tetrahedra and La cations. UV/Vis/NIR diffuse reflectance spectroscopy study shows its optical gap of around 1.75 eV. DFT study indicates an indirect bandgap with an electronic transfer excitation from Se 4p to La 5d orbital electrons.     

The Intermetallic Type-I Clathrate Na8Zn4Ge42

The new intermetallic type-I clathrate Na₈Zn₄Ge₄₂ was obtained by direct reaction of the elements, and its crystal structure was determined by means of single-crystal X-ray diffraction methods. The structure is described in space group Pm3 n (no. 223) with a = 10.6982(1) Å. A mixed Zn/Ge occupancy is found for one of the network sites (6c). Na₈Zn₄Ge₄₂ represents an air-stable electron-precise Zintl phase with exclusively Na cations located in the cavities of a polyanionic host network of four-connected Zn and Ge atoms.