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131.
2-噻吩乙酸在3种树脂上的吸附行为研究 总被引:15,自引:0,他引:15
通过静态吸附实验 ,研究了XAD 4、NDA 10 0和ND 90吸附树脂对水溶液中 2 噻吩乙酸的吸附热力学及动力学特性 ,结果表明 ,2 噻吩乙酸在XAD 4树脂上是单层吸附 ,符合Langmuir等温吸附方程 ,吸附过程符合准一级动力学吸附方程 .2 噻吩乙酸在NDA 10 0和ND 90树脂上的吸附也能用Langmuir等温吸附方程表示 ,但并不只是单层吸附而主要是由毛细管凝聚和微孔填充作用造成的 ,吸附过程可分为大孔和中孔区的吸附以及微孔区的吸附两个阶段 ,两个阶段都符合准一级动力学吸附方程 相似文献
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A comparison of the adsorption of benzoic acid and p-nitrobenzoic acid on the new hypercrosslinked polymeric adsorbent AM-I, with that by macroporous Amberlite XAD-4, including the equilibrium adsorption isotherms, the dynamic adsorption behaviors through column and the adsorption thermodynamics were studied. Results show that Freundlich equation gives a fitting adsorption isotherm. The specific surface of AM-l is only 67% of that of Amberlite XAD-4, but the adsorption capacities on AM-1 are much higher about 125%~166% than that on Amberlite XAD-4,which is contributed to the micropore mechanism and polarity. The negative values of the adsorption enthalpy are indicative of an exothermic process. Enthalpy and free energy changes of adsorption both manifest a physic-sorption process. The negative values of the adsorption entropy indicate that the adsorption is well consistent with the restricted mobilities and the configurations of the adsorbed benzoic acid molecules on the surface of studied adsorbents with superficial heterogeneity. Both adsorbents were used in mini-column experiments for adsorbing benzoic acid expecting to elucidate the higher breakthrough adsorption capacity of the new hypercrosslinked polymeric adsorbent AM-1 as compared with that of Amberlite XAD-4. 相似文献
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135.
降压活性成分淫羊藿甙的HMQC和HMBC谱研究 总被引:1,自引:0,他引:1
首次对中药淫羊藿中降压活性成分淫羊藿甙的HMQC和HMBC谱进行了深入研究,结合1H-1H COSY谱,确切归属了全部碳氢信号,并直接从HMBC谱上确认了异戊烯基,甲氧基,鼠李糖和葡萄糖在黄酮母核上的连接位置,并修正了文献中关于该化合物某些碳信号归属的错误.显示这两种2D NMR新技术对结构复杂的黄酮甙类化合物的结构研究具有重要意义. 相似文献
136.
In this paper, the pH-dependent binding of Eosin Y and bovine serum albumin (BSA) was investigated by spectral methods, including resonance light scattering (RLS), absorption and fluorescence spectrometry. Due to the pH-dependent structure of Eosin Y and BSA, the interaction of BSA and Eosin Y depended on the solution pH value. Especially at pH 2.6 and 9.2, the RLS intensity of BSA was obviously enhanced in the presence of Eosin Y. However, the fluorescence intensity of BSA was quenched in the presence of Eosin Y. To fully understand the pH-dependent binding of BSA and Eosin Y, fluorescence quenching technique was introduced. Based on the fluorescence data obtained, the style of binding, the binding constant, the binding site number and the thermodynamic parameters for the interaction of BSA and Eosin Y were studied. Based on Förster non-radiation energy transfer theory, the distance between donor BSA and acceptor Eosin Y was obtained. 相似文献
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139.
用手持式测碘仪现场测定食盐中的碘 总被引:6,自引:0,他引:6
在自行研制的手持式高灵敏光度计的基础上,研制出一种动态线性范围宽、样品和试剂用量少、分析速度快、无可动部件、灵敏度高、结构简单、轻便耐用、耗电量低的毛持式测碘仪,同时开发了一种测碘专用试剂包,发明了一种碘盐现场取样技术,建立了一种现场测定食盐中碘含量的灵敏、快速、廉价方法。使用手持式测碘仪和专用测碘试剂包测定碘的线性范围是0.01-3mg/L,定是检测下限量0.01mg/L,样品经过研磨以后,测定的相对标准偏差在1.5%以内;如样品不研磨,其相对标准偏差为6%-8%。应用于食盐中碘的现场测定,每个样品的分析测定时间约为3-6min。应用于5种不同品牌食盐样品的实际分析,结果满意。 相似文献
140.
Aimin Huang Guanguang Xia Franz-Josef Spiess Xiao Chen Jeffery Rozak Steven L. Suib Tomonori Takahashi Yuji Hayashi Hiroshige Matsumoto 《Research on Chemical Intermediates》2001,27(9):957-974
Decomposition of CF4 by glow-discharge and arc plasmas was studied using a tubular quartz reactor, a disk type, and a T-type quartz reactor. The effects of different metal electrodes, input voltage, and reactor type on the efficiency of CF4 total destruction (DRE) were studied. The T-shape reactor was more efficient in CF4 destruction than either the disk or tubular type due to a combined effect of glow discharge and arc plasmas. Several hydrogen and oxygen sources, such as H2O, H2, O2, and CH4, were used to convert CF4. Using H2 and O2 as the hydrogen and oxygen sources presented better DRE than using H2O. The effect of different hydrogen and oxygen sources on the conversion of CF4 followed the trend: (H2 + O2) > (CH4 + O2) > H2O. The maximum DRE of 95% was observed with 0.5% CF4 using H2 and O2. A mass spectrometer and an emission spectroscope equipped with a charge-coupled detector (CCD) were used to characterize the products and intermediates. Mass spectrometric studies indicated that the reaction products were HF, CO2, and trace amounts of NO. N2 first negative and second positive emission lines were observed in the glow discharge plasmas as well as in the arc plasmas of N2. However, C and F intermediates were observed only in arc plasmas of CF4. Reactions occurring in the glow discharge plasmas and arcs seem to follow different mechanisms. 相似文献