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971.
Summary Two molecularly imprinted polymers (MIP) have been prepared using the acidic drug salicylic acid, which can form intramolecular
hydrogen bond, as the template and acrylamide or 4-vinylpyridine as the functional monomer. HPLC was used to evaluate the
binding performance of the MIP for the template and for several analogues. The results showed that the MIP (P2) prepared using acrylamide as the functional monomer had no molecular imprinting effect whereas that (P1) prepared using 4-vinylpyridine as the functional monomer had a significant molecular imprinting effect. The reason the molecular
imprinting effect was different for the two MIP was elucidated and the molecular recognition properties of P1 were studied in detail. It was confirmed that electrostatic interaction played an important role in the molecular recognition
of P1. Scatchard analysis showed that two types of binding site with distinctly different affinity were formed in P1. Their dissociation constants were estimated to be 7.6×10−5 mol L−1 and 3.2×10−3 mol L−1, respectively. Because P1 has high affinity and selectivity for salicylic acid not only in organic systems but also in water-containing systems, it
gives P1 the potential for use in the enrichment, separation, and detection of salicylic acid in biological fluids. 相似文献
972.
Amorphous poly(ethylene terephthalate) was annealed at temperatures around the glass transition temperature and then heated up in differential scanning calorimeter at 20 °C min−1. It was found that the annealing favored the subsequent cold crystallization and this effect became stronger with increasing annealing temperature. The experimental results were explained by considering the structural change during the annealing. 相似文献
973.
A method for the determination of the major serotonin metabolite — 5-hydroxyindole-3-acetic acid (5-HIAA) in human gastric juice by cyclic voltammetry was described. The measurement conditions were investigated. The potential window was chosen from +0.1 to +0.9 V, the supporting electrolyte was 0.025 M PBS solution (pH 2.0). The method allowed determination in the concentration range from 2.0 ×10−7 to 2.0 ×10 −5 M and a detection limit of 80 nM. When samples of gastric juice were analyzed with the method, we obtained the mean content of 5-HIAA in the gastric juice. Meanwhile, interference from other ions and substances were examined. The experimental results indicate that the method for the determination of gastric juice samples is successful. 相似文献
974.
煤微孔表面的分形维数及其变化规律的研究 总被引:4,自引:2,他引:4
本文利用气体吸附数据确定了各种煤阶煤(从褐煤到无烟煤)和煤焦气化反应过程中微孔表面的分形维数及其变化规律。这有助于进一步认识煤的孔结构特征。 相似文献
975.
976.
本文对在玻璃碳电极上不可逆溶出催化的理论进行了研究,推导了溶出催化过程的电流方程,峰电流和峰电势方程,并用微计算机模拟出各种关系曲线,从理论方程得知溶出催化伏安法所得的峰电流比溶出伏安法的峰电流提高了二个数量级。本文还用钯的溶出催化实验验证理论方程,所得的实验结果均与理论方程相吻合。 相似文献
977.
富镉Hg_(1-x)Cd_xTe是一种新型的光电转换材料,已用于固体结太阳能光伏电池:ITO/CdS/Hg_(1-)Cd_xTe/Au。我们曾对Hg_(1-x)Cd_xTe的电沉积机理作过研究。最近我们用电沉积制备的Hg_(0.09)Cd_(0.91)Te多晶薄膜做成了液体结太阳能光电化学电池并观察到明显光电响应。 相似文献
978.
本文通过无水三氯化希土与等摩尔的甲基环戊二烯基钠(Cp′Na)在四氢呋喃(THF)中反应,合成了八个新的中性甲基环戊二烯基希土二氯化合物Cp′LnCl2·3THF[Ln=Sm(1), Eu(2), Gd(3), Tb(4), Dy(5), Ho(6), Er(7), Y(8)],并研究了茂环上甲基取代基对一茂二氯希土配合物分子结构及稳定性的影响。元素分析、红外光谱和质谱鉴定结果表明这八个化合物都是溶剂化的单体结构,其中配合物7的结构还用单晶X射线分析确证。 相似文献
979.
文中直接取硫酸样品3ml于装有约10ml水的25ml比色管中,加入碘化钾溶液2ml,用水稀至刻度。加入甲基异丁酮5ml,萃取lmin,分层后,在有机相中测定铅、镉、铜含量;在水相中测定锌含量。方法的加标回收率为98.9%~103%,精密度1.8%~4.3%,标准曲线法和标准加入法结果相近,倍比试验结果亦相吻合,方法快速简便、准确,适合于工业中的快速分析。 相似文献
980.
RING-OPENING POLYMERIZATION OF TRIMETHYLENE CARBONATE CATALYZED BY NOVEL SINGLE COMPONENT RARE EARTH CALIXARENE COMPLEXES 总被引:2,自引:0,他引:2
Wei-puZhu JunLing HongXu Zhi-quanShen 《高分子科学》2005,(4):407-410
In this paper, ring-opening polymerization of trimethylene carbonate (TMC) with rare earth (Nd, Y, La) p-tert-butylcalix[n]arene (n=4, 6, and 8) complexes as catalysts has been studied. Poly(trimethylene carbonate) (PTMC) with Mv of 21,400 was produced by bulk polymerization under the conditions as follows: [TMC]0/[Nd] (molar ratio)=1000,80℃,8h. Mechanism study reveals that the polymerization proceeds via a coordination mechanism. 相似文献