显微共焦拉曼光谱研究电化学合成聚苯胺膜

显微共焦拉曼技术被用来研究电化学合成的聚苯胺（PANI）膜. 研究结果表明：在不同的激发光聚焦深度，聚苯胺膜的拉曼光谱有明显变化.从而反映出聚苯胺膜的掺杂程度在膜生长过程中随膜厚度的增长而增加. 并由X射线电子能谱（XPS）和紫外吸收光谱（UV）分析证实.     

Determination of daidzein and genistein in soybean foods by automated on-line in-tube solid-phase microextraction coupled to high-performance liquid chromatography

An automated on-line method for the determination of the isoflavones, daidzein and genistein, was developed using in-tube solid-phase microextraction coupled to high-performance liquid chromatography (in-tube SPME-HPLC). In-tube SPME is a new extraction technique for organic compounds in aqueous samples, in which analytes are extracted from the sample directly into an open tubular capillary by repeated draw/eject cycles of sample solution. Daidzein, genistein and their glucosides tested in this study were clearly separated within 8 min by HPLC using an XDB-C8 column with diode array detection. In order to optimize the extraction of these compounds, several in-tube SPME parameters were examined. The glucosides daidzin and genistin were analyzed as aglycones after hydrolysis because the glucosides were not concentrated by in-tube SPME. The optimum extraction conditions for daidzein and genistein were obtained with 20 draw/eject cycles of 40 microl of sample using a Supel-Q porous layer open tubular capillary column. The extracted compounds were easily desorbed from the capillary by mobile phase flow, and carryover was not observed. Using the in-tube SPME-HPLC method, the calibration curves of these compounds were linear in the range 5-200 ng/ml, with a correlation coefficient above 0.9999 (n = 18), and the detection limits (S/N = 3) were 0.4-0.5 ng/ml. This method was successfully applied to the analysis of soybean foods without interference peaks. The recoveries of aglycones and glucosides spiked into food samples were above 97%.     

Application of heat conduction calorimetry to high explosives

This paper describes some thermal analysis experiments conducted on high explosive samples. These employ differential scanning calorimetry to monitor thermal effects at elevated temperatures (around 200 °C) and heat conduction calorimetry to record thermal effects at much lower temperatures (below 100 °C).The work shows that, due to the generally high thermal stability of many high explosive compositions, heat generation rates are very low, if detectable at all, at normal storage temperatures, even when using a very sensitive instrument. The sensitivity and reproducibility of this technique has been investigated in detail by Wilker et al. [S. Wilker, U. Ticmanis, G. Pantel, Detailed investigation of sensitivity and reproducibility of heat flow calorimetry, in: Proceedings of the 11th Symposium on Chemical Problems Connected with the Stability of Explosives, Sweden, 1998] and shown to be capable of recording heat generation rates of less than a microwatt. This allows continuous measurement of decomposition processes in nitrate ester based propellants at temperatures as low as 40 °C. However, the measurement of very low levels of heat generation is difficult, time consuming and therefore expensive. If the assumption is made that the life limiting process is invariably the slow decomposition of the energetic component, this will frequently lead to very long service lifetime predictions.A number of possible complications are identified. Firstly, due to its low detection threshold, a heat conduction calorimeter may detect other reactions which will not lead to failure, but which may still dominate the heat flow signal. Secondly, the true failure process may generate little energy and be overlooked. In view of these considerations, at present it seems unwise to rely on heat conduction microcalorimetry as the only tool for the assessment of the life of high explosive energetic systems.Based on examples of life terminating processes in high explosives during storage and use, it is clear that decomposition of the energetic material is not invariably the cause of system failure. It is also by no means the only reaction that may take place in, and be observed by, a heat conduction calorimeter.     

Solventless injecction for packed column supercritical fluid chromatography

The adverse effects of injection solvent strength on microbore packed column SFC band broadening are demonstrated and a solventless injection system that eliminates these effects is introduced. The injection system removes solvent in a GC-like manner using a retention gap and an on-column capillary GC syringe. The analyte is delivered to the analytical column in a solvent-free plug of supercritical fluid mobile phase.     

C2H4-K体系中振动态至电子态传能的研究

用TEA CO_2激光将C_2H_4分子激发到高振动激发态，高振动激发态的C_2H_4分子与基态的K原子碰撞发生振动态→电子态（V→E）传能过程，根据提出的能级组模型，对测得的时间分辨原子荧光信号进行处理，获得温度在453－663 K范围内，C_2H_4-K体系中V→E传能速率的数量级为10~(-10)/cm~3·molecule~(－1)·s~(－1)，对应的碰撞传能截面约为0.30～0.80 nm．随着反应温度升高，V→E传能截面减小．上述实验结果表明碰撞体间吸引相互作用在这种非共振的V→E传能过程中起主要作用．利用多极相互作用势下的碰撞络合物模型对实验结果进行了讨论．     

A convergent synthesis of octadeca-2E, 13Z-dienyl acetate, a pheromone component ofSynanthedon tipuliformis C.

A convergent synthesis of octadeca-2E, 13Z-dienyl acetate, a pheromone component ofSynanthedon tipuliformis C., has been developed. The synthesis is based on cross-coupling of 8-iodooct-2E-en-I-ol THP ether with dec-5Z-enyl bromide catalyzed by CuBr. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1529–1531, August, 1997.     

Synthesis and characterization of sulfone-containing polyesters derived from 4,4′-dicarboxydiphenyl sulfone by direct polycondensation

Several sulfone-containing polyesters having inherent viscosities 0.43-0.19 dL g^?1 were prepared by direct polycondensation of 4,4′-dicarboxydiphenyl sulfone (DCDPS) with various aromatic and aliphatic diols, by p-toluenesulfonyl chloride and N,N′-dimethylformamide in pyridine solution. The polyesters were examined by elementary analysis, IR spectra, inherent viscosity, x-ray diffraction, solubility, DSC, and TGA. The diffraction diagram showed that all polyesters were crystalline except that obtained from bisphenol-A. All polymers were soluble in sulfonic acid (18M), phenol and p-chlorophenol, but not in acetone and toluene. These polymers obtained from aromatic bisphenols lost no mass below 325°C, but 10% loss of mass was recorded above 396°C in nitrogen. DCDPS copolymerized with isophthalic acid (IPA) and bisphenol-A had inherent viscosity up to 0.49 dL g^?1, with relatively narrow distribution of molar mass . © 1995 John Wiley & Sons, Inc.     

Phenol methylation over CrPO4 and CrPO4?AlPO4 catalysts

The vapor-phase catalytic alkylation of phenol with methanol and dimethyl carbonate on a series of differently prepared CrPO₄ (Cr/P=1) and CrPO₄-AlPO₄ (CrAIP) catalysts, has been studied at different temperatures (473–673 K). The reaction is first order in phenol, giving a mixture of O- and C-alkylated products (C-alkylation taking place preferentially at theortho-position). Moreover, dimethyl carbonate is a better methylating agent than methanol.     

光解苯半醌和2-羟基-2-丙基自由基的CIDEP谱

用高时间分辨ＥＳＲ波谱仪测量了光解苯半醌和２－羟基－２－丙基自由基的ＣＩＤＥＰ谱,苯半醌自由基的ＣＩＤＥＰ属ＴＭ机理,实验研究了微波功率,溶液浓度对苯半醌自由基的ＣＩＤＥＰ谱时间演化的影响,２－羟基－２－丙基自由基的ＣＩＤＥＰ属ＲＰＭ机理,实验研究了自旋极化的生成环境。     

Darstellung und Charakterisierung der Trisilylphosphane (Ph 3Si) n P(SiMe 3)3−n,n=1,2,3

A simple preparation of the title compounds is achieved by reacting Na₃P/K₃P with stoichiometric mixtures of chlorotriphenylsilane and chlorotrimethylsilane.³¹P- and²⁹Si-NMR-Data as well as Ir and Raman spectra of the compounds are reported.