聚合物支载合成杂环化合物的研究进展

聚合物支载的反应与传统的经典液相反应相比，具有独特的优点，广泛应用于 杂环化合物的合成。综述了近年来杂环化合物的固相和液相合成研究。     

邻氨基酚电聚合膜的研究

在酸性溶液中, 邻氨基酚(OAP)可电聚合成均匀的活性聚邻氮基酚膜(POAP), 膜有致密结构和“张开”结构。POAP膜的主要结构形式为: 与Ni~(2+)络合后, 形成POAP—Ni~(2+)膜, 其主要结构形式为:     

Metallosilicates as supports of Co catalysts for the synthesis of liquid hydrocarbons from CO and H2

The effect of the nature of the silicate support on the activity and selectivity of 10%. Co/M silicate catalysts (where M=Cu, Zn, Ce, Ti, Hf, La, Al, Zr, Co, Mg) in the synthesis of hydrocarbons from CO and H₂ has been established. Co and Zr catalysts have been shown to provide the highest catalytic efficiency. The yield of liquid hydrocarbons in their presence exceeds 120 g m^–3.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 480–482, March, 1993.     

Kaolin as support for porous layer open tubular columns

Summary PLOT columns have been prepared with kaolin as the liquid phase support. These columns show good efficiency with different stationary phases and good thermal stability with polar phases. The performance of columns is shown by the separation of various mixtures such as fatty acids, phenols and anilines which are of analytical importance.     

Simultaneous purification and reversible immobilization of d-amino acid oxidase from Trigonopsis variabilis on a hydrophobic support

Purification and reversible immobilization of d-amino acid oxidase from Trigonopsis variabilis could be simultaneously accomplished by hydrophobic interaction on Phenyl Sepharose CL-4B in the presence of 50 mM pyrophosphate buffer (pH 8.5). The presence of a high salt concentration of 2M, which is generally required for the hydrophobic interactions, was not essential for the hydrophobic immobilization. The enzyme in free as well as immobilized form was optimally active between pH 7.0 and 9.0. The immobilized preparation could be reused in a batch process for the conversion of d-amino acids to α-keto acids. When the activity of the preparation dropped below practical limits, the gel could be regenerated by water wash and recharged with fresh crude extract from yeast.     

Influence of pretreatment conditions on low-temperature CO oxidation over Au/MOx/Al2O3 catalysts

Composite oxide MO_x/Al₂O₃ supported gold catalysts for low-temperature CO oxidation were prepared and investigated. The presence of transition metal oxide was proved to be beneficial to the improvement of catalytic performance of Au/Al₂O₃ catalysts for low-temperature CO oxidation. Furthermore, the influence of various pretreatment conditions on Au/MO_x/Al₂O₃ catalysts was studied carefully. The image of TEM showed that gold catalyst with small gold particles only in the form of a fine dispersion exhibited highly catalytic activity. The XPS, Fourier transform infrared (FTIR) spectroscopy characterization results of Au/FeO_x/Al₂O₃ catalyst showed that gold catalysts having partially oxidized gold species have the best catalytic performance. One possible pathway for CO oxidation on Au/FeO_x/Al₂O₃ catalyst is that the CO adsorbed on gold particles reacts with adsorbed oxygen, which is possible to occur on oxygen vacancies on the support or at the metal–support interface.     

Application of ammonia intermittent temperature-programmed desorption to evaluate surface acidity of tungsten oxide supported on activated carbon

Intermittent temperature-programmed desorption of ammonia was used to study the strength and population of surface acid sites of tungsten oxide supported on activated carbon pretreated at 350 and 700 degrees C. Catalysts pretreated at 350 degrees C showed two types of surface acid sites and desorption occurred with free readsorption until a temperature of around 300 degrees C was reached. Pretreatment at 700 degrees C produced three different states of ammonia adsorbed on the catalysts and desorption occurred with free readsorption.     

基于纹理的图像字符自动定位技术对比研究

随着信息技术的迅速发展,基于内容的图像检索技术引起了研究者的广泛关注.自动抽取图像/视频的语义内容是图像/视频检索中研究的重点和难点.本文通过分析多种字符定位技术,给出了基于纹理分析的字符定位算法的一般框架.对各种基于纹理分析的字符定位方法进行了对比研究,尤其深入地研究了纹理特征提取,分类器设计及边界位置确定对定位结果的影响.最后通过预分类的方法对算法进行改进,实验结果表明,该方法在保持正确定位率基本不变的情况下,可以大幅度提高处理速度.     

基于支持向量机的凝血功能诊断模型

使用凝血四项指标诊断凝血功能是临床的常规检查,但根据经验进行诊断正确率不高.剔除临床上最重要的指标FIB后,建立支持向量机模型诊断的正确率和根据凝血四项指标诊断的正确率没有显著差异,100次模拟的平均正确率分别达到了95.4496%和95.5039%.     

α‐ZrP/Uracil/Cu2+ nanoparticles as an efficient catalyst in the Morita‐Baylis‐Hillman reaction

A facile synthesis of uracil‐Cu²⁺ nanoparticles immobilized on alpha‐zirconium hydrogen phosphate (α‐ZrP), abbreviated as α‐ZrP/Uracil/Cu²⁺, was presented. This compound was synthesized by the thermal method and used as a reusable catalyst for the Morita‐Baylis‐Hillman reaction without any additives. First, (3‐ iodopropyl) trimethoxysilane as a linker is reacted with α‐ZrP support to give the α‐ZrP/IPTMOS. Addition of uracil and then the addition of copper (II) acetate to α‐ZrP/IPTMOS results in the production of selected catalyst. The Morita‐Baylis‐Hillman reaction catalyzed by α‐ZrP/Uracil/Cu^{2 +} demonstrated high product yield, short reaction time and a straightforward work‐up. The catalyst with enough outside surface was easily recovered using centrifugation and reused five times without a significant reduction in its activity.