偏最小二乘法分光光度同时测定复方扑热息痛片中各组分含量

本文介绍了偏最小二乘法(PLS)用于多组分分光光度分析的基本原理和算法.研究了复方扑热患痛片中扑热息痛、阿司匹林和咖啡因的PLS测定方法,各组分的平均回收率分别为99.88±0.33％、99.99±0.14％和99.92±1.24％(置信度95％).     

茶叶中总黄酮含量测定方法的研究

茶叶中富含羟基苯甲酸类、肉桂酸类及原花色素等多酚类物质,这些物质都具有邻苯二羟基结构,碱性环境下与铝离子形成络合物,影响总黄酮的测定。本实验用亚硝酸钠-硝酸铝法和三氯化铝法测定茶叶总黄酮含量的结果作了比较。实验结果表明,亚硝酸钠-硝酸铝法的测定结果比三氯化铝法约高60mg/g,三氯化铝法在酸性环境下进行,酸度实验显示,适宜酸度为pH≥5.0。鞣酸干扰实验表明,平均误差为0.017mg,随着鞣酸量的增加,测得值无上升趋势。三氯化铝法的线性方程:y=0.000638 0.8623x,相关系数:r=0.9998;样品加标回收率为98.05%。因此,对含酚类较多的植物应采用三氯化铝法测定其总黄酮的含量。     

Characterization of some essential oils and their key components: Thermoanalytical techniques

The present study was aimed at determining the kinetics of evaporation and establishing vapor pressure curves for both single and multi-component systems by thermogravimetry (TG) and differential scanning calorimetry (DSC). Essential oils (e.g. lavender oil, orange oil, clove oil and eucalyptus oil, etc.) are typically multi-component systems consisting of various volatile pure components (e.g. linalyl acetate, limonene, cinnamaldehyde, etc.) which resemble single component systems. In this study linalyl acetate was taken as the calibration compound for TG. The vapor pressure curves for the pure substances were plotted using TG and vapor pressure plots for clove oil and eucalyptus oil were constructed using DSC. The thermodynamic and kinetic parameters of the pure compounds were compared to that of the multi-component systems to quantitatively and qualitatively measure the influence of different compounds on each other. The k-value from the vapor pressure data for linalyl acetate was calculated as 112006 Pa kg^0.5mol^0.5s^-1 m^-2 K^-0.5. The vapor pressure values were used to determine the Antoine constants using the SPSS 10.0 software.This revised version was published online in November 2005 with corrections to the Cover Date.     

Quantum chemical studies on the structures, properties and decomposition of the azido derivatives of trinitrobenzenes

The geometries,heats of formation and electronic structures of 15 azido-derivatives of 1,2,3-TNB (Ⅰ),1,2,4-TNB (Ⅱ) and 1,3,5-TNB (Ⅲ) have been studied using quantum chemical AMI method at HF level.The effect of azido substitution on the structures and properties of TNBs has been discussed and the relative stability of the title compounds has been established.The processes of the decomposition of the title compounds by breaking C-NO2,C-N3 and CN-N2 bonds are investigated at UHF-AM1 level.It is shown that the decomposition of the title compounds may be initiated by the cleavage of both C-NO2 and N-N2 bonds.     

利用偏钛酸浆料制备大比表面纳米管钛酸工艺的研究

以偏钛酸浆料为原料通过水热法合成了纳米管钛酸,并采用TEM,比表面积测定仪等分析手段观察其形貌和管径大小,测定了其比表面积和孔体积.同时运用正交实验法考察了反应温度、反应时间对纳米管钛酸比表面积和孔体积的影响.实验结果表明,所制备的纳米管钛酸平均比表面积高达 340m2 /g,最佳的制备工艺是:工业碱NaOH的质量分数为 25. 7 %、偏钛酸浆料的质量分数为 17. 1 %、后处理酸度为pH=1、反应温度为 120℃、反应时间为 20h.     

熔融浸渍法制备锂离子电池正极材料LiMn2O4的研究

采用LiNO3和MnO2为原料,在650℃下制备了尖晶石型的LiMn2O4.通过X射线衍射、扫描电子显微镜、热重分析和电化学性能测试,发现该化合物具有很高的放电比容量和较好的循环性能,首次放电比容量可达到122 mA·h/g.并对循环性能衰减的各种因素进行了讨论.     

Darstellung und Kristallstruktur von TICu[CuO2]

Investigations on Electronically Conducting Oxide Systems. XVI. Solid Solutions and Conductivity in the System MgTi₂O₅? Ti₃O₅ Solid solution formation is reported for the system Mg_1–xTi_2–x^IVTi_2x^IIIO₅. With increasing x there is at room temperature a transition from the orthorhombic pseudobrookite structure to the monoclinic low-temperature modification of Ti₃O₅. The X-ray diffraction pattern results are supported by DSC measurements, electrical and magnetic investigations. The tendency of Ti? Ti pair formation in the low-temperature Ti₃O₅ structure is accompanied by a drop of the activation energy for electrical conductivity and a decreasing susceptibility at high Ti^III concentrations.     

温度及pH敏感的树枝状高分子衍生物合成及药物控制释放研究

对合成的系列聚酰胺-胺型(PAMAM)树枝状高分子进行端基的羟基化和氯乙酰化两步修饰,使PAMAM最外层接上烷基氯.以修饰产物为引发剂,通过原子转移自由基引发甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)聚合得到树枝状PAMAM高分子衍生物,并对其结构用FTIR、1H-NMR和粒径分析进行了表征.紫外可见分光光度仪测定证实此高分子具有温度及pH敏感性.通过对小分子药物控制释放研究表明,此树枝状高分子衍生物通过环境pH值可有效地控制小分子药物的释放.     

微乳凝胶法制备MoO3/SiO2纳米复合氧化物及DSC-TG分析

由微乳凝胶法制备了一系列不同MoO3含量的MoO3/SiO2纳米复合氧化物,运用DSC-TG,TEM,XRD和FT-IR等技术对其进行了相应表征.结果表明:所制备复合氧化物适宜的焙烧温度为300℃;样品粒径分布在20~24 nm;样品中MoO3在SiO2表面分散良好,其单层分散阈值在12~12.5%之间;表面Mo与Si原子以Mo—O—Si键联接.