On-chip potential gradient detection with a portable capillary electrophoresis system

A portable chip-CE system with potential gradient detection (PGD) was developed and applied to the determinations of alkali metals and alkaloids. The separation efficiency appeared to be satisfactory and nonaqueous capillary electrophoresis (NACE) proved to be applicable to PGD or conductivity detection. The power supplies, separation and detection were built on a device of 3 kg in weight. A branch channel near the end of the separation channel was designed to perform PGD and make the application of relatively high field strength possible. The study is the first report on the application of PGD on the microchip platform. The design of the chip-CE system shows several advantages, such as simplicity, miniaturization and wide applicability.     

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。     

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.     

A novel method for synthesizing diorganylphosphinous acids from red phosphorus and arylalkenes

The reaction of styrene and -methylstyrene with P in aprotic polar solvents in the presence of KOH affords diorganylphosphinous acids.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1680–1681, September, 1994.     

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.     

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.     

AM1法研究乙烯与环己－1，3－二烯热加成反应

用ＡＭ１方法（采用非限制的Ｈａｒｔｒｅｅ－ＦｏｃｋＵＨＦ计算）研究乙烯与环己－１，３－二烯的热Ｄｉｅｌｓ－Ａｌｄｅｒ反应。结果表明反应是放热的且存在两条竞争的路径；协同反应的活化能以及双自由反应速度控制步骤的活化能分别为１１２．６６７ｋＪ／ｍｏｌ和７８．４０６ｋＪ／ｍｏｌ。