新型氧离子导体La2Mo1.8Ga0.2O9陶瓷的合成及其电性能

通过高温固相合成法首次合成了La₂Mo_1.8Ga_0.2O₉陶瓷样品. 粉末XRD结果表明, 该样品为单一立方相La₂Mo₂O₉结构. 以陶瓷样品为固体电解质、多孔性铂为电极, 采用交流阻抗谱、气体浓差电池、氧泵等方法研究了样品在600～1000 ℃下各种气氛中的离子导电特性. 结果表明, 氧浓差电池电动势的实测值与理论值吻合得很好, 氧离子迁移数为1, 表明该陶瓷样品在该温度下氧气气氛中为一纯氧离子导体; 氧泵(氧的电化学透过)实验结果进一步证实了该样品在氧气气氛中为一纯氧离子导体; 在氧分压p(O₂)＝10^－5～10⁵ Pa的高氧分压气氛中, 电导率与氧分压变化基本无关, 表明在该氧分压范围内样品为纯离子导体, 这与氧浓差电池电动势测定结果相吻合; 在低氧分压为10^－5～10^－15 Pa范围内, 总电导率随氧分压降低而稍有升高, 表明在该氧分压范围样品为氧离子与电子的混合导体; 在600～1000 ℃下氧离子电导率＞10^－2 S•cm^－1, 显著高于母体La₂Mo₂O₉的氧离子电导率, 1000 ℃时的氧离子电导率为0.07 S•cm^－1.     

Direct Electrochemistry of Hemoglobin Immobilized in Sodium Alginate Film on the Ionic Liquid [BMIM]PF6 Modified Carbon Paste Electrode

In recent years the direct electron transfer of redox protein on electrode surface has attracted great attentions1. Different kind of modified electrode and various supporting films for immobilization of proteins had been proposed. But most of them are ba…     

CS2+离子 C2Σg+←B2Σu+跃迁的Franck-Condon因子计算以及与光解离谱的比较

将线性三原子分子离子CS2+的对称伸缩振动简化为SC和S之间的简谐振动, 用谐振子的势能曲线和波函数对CS2+分子离子 C2Σg+和 B2Σu+电子态(对称伸缩)振动能级间跃迁的Franck-Condon因子进行了计算, 得到的结果与 C2Σg+←B2Σu+跃迁的光解离谱实验强度进行了比较, 对前人给出的分子数据(转动常数、分子平衡核间距)进行了验证和分析, 讨论了经由 C2Σg+←B2Σu+电子态振动能级间跃迁的光解离机理.     

STUDIES ON THE SPHERULITE FORMATION IN MELT CAST POLYCAPROLACTONE BASED POLYURETHANES

A series of PCL/MDI/BDO segmented polyurethanes have been synthesized by two-step method in solution.The hard segment content ranges from 10% to 48% by weight, and the molecular weight of PCL diols is 1500. Hard segment spherulites have been observed in compression molded specimens of all of the samples except the one of the lowest hard segment content. The difficulty in sphernlite formation was explained as only in a small temperature range,the microphase separation rate may be faster than the crystallization rate and all these processes are very slow due to the hydrogen bonding between hard and soft segments and the interactions between hard segments themselves. PCL soft segments of molecular weight 1500 is still crystallizable and may form different crystalline superstructures.     

Synthesis and Crystal Structure of Ag2（admtrz）2（CF3CO2）2（admtrz=4—amino—3,5—dimethyl—1,2,4—triazole）

1 INTRODUCTION Transition metal complexes bridged by 1, 2, 4-triazole group can produce interesting structures and specific properties[1]. Many attempts have been made to synthesize a variety of complexes with paramagnetic centers by using such ligands, and their structures and magnetic properties have been characterized[2]. However, the polynuclear Ag(I) complexes bridged by 1, 2, 4-triazole have been poorly studied[3]. Recently, we have prepared a series of silver(I) triazole complex…     

Preparation and application of functionalized nanoparticles of CdS as a fluorescence probe

CdS nanoparticles have been prepared and modified with mercaptoacetic acid. The functionalized nanoparticles are water-soluble and biocompatible. They could be used as a fluorescence probe in the determination of bovine serum albumin (BSA), which was proved to be a simple, rapid and specific method. In comparison with single organic fluorophores, these nanoparticle probes are brighter, more stable against photobleaching, and do not suffer from blinking. Under the optimum conditions, the response is linearly proportional to the concentration of BSA between 0.1 and 3.2 μg ml⁻¹, and the limit of detection is 0.08 μg ml⁻¹.     

Ln(Ⅲ)与2-羟基-1-萘醛缩蛋氨酸盐及邻菲咯啉三元配合物的合成与表征

合成了稀土硝酸盐与希夫碱盐2-羟基-1-萘醛缩蛋氨酸钾(以KL表示)及邻菲咯啉(Phen)的四种固体三元配合物。通过元素分析，IR，UV，DTA-TG及摩尔电导分析等手段确定配合物的组成为[Ln(L)(Phen)(NO3)(H2O)]NO3(Ln＝Gd，Dy，Er，Yb)，并对它们的配合方式及某些物理和化学性质进行了研究。     

(C(wedge)N(wedge)N)Pt(C identical to C)nR] (HC(wedge)N(wedge)N = 6-aryl-2,2'-bipyridine,n = 1-4, R = aryl,SiMe3) as a new class of light-emitting materials and their applications in electrophosphorescent devices

Tridentate cyclometalated platinum(II) complexes bearing sigma-alkynyl ligands exhibit tunable photoluminescence and enhanced stability during vacuum deposition; OLEDs based on these materials display orange to red electrophosphorescence with low turn-on voltages (approximately 4 V), maximum luminance approaching 10,000 cd m-2 and efficiency up to 4.2 cd A-1.     

Host–Guest Complexation of <Emphasis Type="Italic">β</Emphasis>-, <Emphasis Type="Italic">γ</Emphasis>-Cyclodextrin with Alkyl Trimethyl Ammonium Bromides in Aqueous Solution

As a continuation of our previous investigation, interactions between cyclodextrin (β-CD), γ-cyclodextrin (γ-CD) and alkyl trimethylammonium bromides in aqueous solutions have been studied with titration calorimetry and ¹H NMR at 298.15 K. The results are discussed in terms of the amphiphilic interaction of CD with surfactants and the iceberg structure formed by water molecules existing around the hydrophobic tail of surfactant molecules. The stoichiometry of the β-CD–surfactant system is 1:1 whereas that of the γ-CD–surfactant system is 1:2. The corresponding formation enthalpy (negative) of the complexes of the two systems decreases with an increase in the number of carbon atoms (n) in hydrophobic chain of surfactant molecule, C _n H_2n+1, whereas the entropy increases with the enlargement of n.     

Selective determination of uric acid in the presence of ascorbic acid using a penicillamine self-assembled gold electrode

The electrochemical behaviors of uric acid (UA) at the penicillamine (Pen) self-assembled monolayers modified gold electrode (Pen/Au) have been studied. The Pen/Au electrode is demonstrated to promote the electrochemical response of UA by cyclic voltammetry (CV). The diffusion coefficient D of UA is 6.97 × 10⁻⁶ cm² s⁻¹. In differential pulse voltammetric (DPV) measurements, the Pen/Au electrode can separate the UA and ascorbic acid (AA) oxidation potentials by about 120 mV and can be used for the selective determination of UA in the presence of AA. The detection limit was 1 × 10⁻⁶ mol L⁻¹. The modified electrode shows excellent sensitivity, good selectivity and antifouling properties.