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991.
聚硅氧烷聚脲多嵌段共聚物中氢键的研究 总被引:4,自引:0,他引:4
采用多种手段研究了聚硅氧烷与聚脲嵌段共聚物中所存在的各类氢键.特别探讨在聚硅氧烷软段中引入极性氰丙基对体系成氢键能力的影响和两相间相互作用力的情况结果表明,在软段分子中引入极性氰丙基有利于增加聚硅氧烷分子与聚脲链段的相互作用,这一相间作用力使两相间界面层厚度随着硬段分子量的增加而加宽,并发现在聚硅氧烷聚脲嵌段共聚物中硬段的聚集形态随溶液浓度改变变化不大,其中氢键随着温度升高而下降. 相似文献
992.
Carabias-Martínez R Rodríguez-Gonzalo E Domínguez-Alvarez J García Pinto C Hernández-Méndez J 《Journal of chromatography. A》2003,1005(1-2):23-34
A preconcentration study based on the cloud point phenomenon was carried out for a set of triazine herbicides, three of them chloro-substituted and three of them methylthio-substituted. Concentration factors and recoveries were calculated as function of the percentage of the non-ionic surfactant Triton X-114 employed. From these values, obtained from a cloud point extraction (CPE) procedure, the distribution coefficient between the Triton X-114 micelles and water, Kc, prior to CPE was calculated for each triazine and related to the corresponding octanol-water partition coefficient, Kow. In order to confirm the results obtained with the triazine herbicides, two sets of data from chemically different organic pollutants--organophosporous and chlorophenols--obtained from the literature were assessed, concluding that they display a similar behaviour to that of the triazine herbicides. This can be used to predict the CPE behaviour of other organic pollutants from their octanol-water partition coefficients. The Kc values were compared with the analyte concentration ratio in the surfactant-rich phase and aqueous phase (Ksa) with a view to obtaining a link between the analyte behaviour prior to and after cloud point extraction procedures. 相似文献
993.
QiongCHENG TuZhiPENG XiaoBoHU CatherineF.YANG 《中国化学快报》2004,15(12):1473-1476
A novel fibroin modified electrode with ion recognition was reported. The membrane with isoelectric point of pH 4.5, was modified on graphite and carbon fiber electrodes. The pH-responsive ion recognition of the modified electrode was investigated by use of some neurocompounds. The fibroin carbon fiber electrode has been used for in-vivo determination. 相似文献
994.
995.
靛红掺杂聚吡咯膜修饰电极的电荷传输 总被引:5,自引:1,他引:5
利用交流阻抗法研究了靛红掺杂聚吡咯膜内的电荷传输,通过非线性最小二乘法拟合,得出了体系的等效电路,并计算出其电荷扩散系数和异相电子传递反应速率常数。实验结果表明,随着膜厚的增加,活性点增多,异相电子传递反应速率常数增大,同时表观扩散系数也增大。 相似文献
996.
热喷雾作为电感耦合等离子体原子发射光谱的进样技术 总被引:3,自引:1,他引:3
设计并建立了热喷雾器及其去溶装置。用热喷雾作为电感耦合等离子体原子发射光谱的进样技术,并对其性能作了系统研究。与气动雾化器比较,对23个元素检出限的改善为5 ̄20倍。 相似文献
997.
The principle of tandem on-line continuous separation techniques as an alternative means of introducing samples into plasmas was applied to the development of a sensitive, selective and convenient method for the determination of arsenic by inductively coupled plasma atomic emission spectrometry (ICP-AES). Arsenic is continuously extracted as AsI3 into xylene from the sample dissolved in 0.1 M potassium iodide solution in 7.2 M hydrochloric acid. The xylene phase (containing the analyte) is continuously mixed on-line with NaBH4 in dimethylformamide and acetic acid solutions. Arsine is thus continuously generated directly from the organic phase and is separated in a gas—liquid separation device which prevents most of the xylene phase vapour from reaching the ICP. The system was optimized for the continuous extraction of AsI3, the direct generation of arsine from xylene and the final ICP determination of arsenic. Finally, the tandem on-line continuous separation ICP detection system was applied to the determination of arsenic in real samples (white metal, cast iron, cupro-nickel and orchard leaves standard materials). Very good agreement between the experimental results and the certified values was obtained. 相似文献
998.
碳十八键合锆胶固定相的制备与色谱性能评价 总被引:5,自引:0,他引:5
用诱导聚合胶体凝聚法(PICA)制得的二氧化锆微球与碳十八三乙氧基硅烷反应制备了碳十八键合锆胶固定相(ODZ),评价了该柱填料的色谱性能,并用此固定相分离了中性和碱性化合物。 相似文献
999.
A new complex [Ni(en)3]4[HVⅣ12VⅤ6O42(PO4)] has been hydrothermally synthesized and characterized by X-Ray diffraction, IR and Elemental analysis. Single crystal X-ray analysis indicates that this compoud crystallizes in cubic system,space group Im 3m with a=17.4081(2)?, V=5275.38(10)?3, R=0.0420, wR=0.1055, Z=2, Dc=1.663g·cm-3, μ=2.297mm-1, F(000)=2636. The crystal structure consists of [Ni(en)3]2+ cations and {HV18O42(PO4)}8- cluster anion which construct from 18 {VO5} square pyramids. The VO5 pyramids joined each other to form a {V18O42} cage hosting a tetrahedral {PO4}3- moiety with disordered oxygen atoms. CCDC: 185574. 相似文献
1000.
随着油田深部调剖应用的不断推广,以及环保要求的提高,适用于深部调剖调驱体系的低污染有机锆交联剂逐渐受到关注。以ZrOCl2·8H2O、乳酸、乙二胺、硫脲为原料,制备了有机锆交联剂和HPAM-锆交联凝胶,其结构和性能经SEM和岩心驱替装置表征。并利用正交实验法优化了制备条件。结果表明:制备有机锆交联剂的最佳条件为:氧氯化锆、乳酸、乙二胺及硫脲的质量比为7.8/1/6.7/5,反应温度为70 ℃,反应时间为3 h。交联温度为60 ℃,HPAM浓度为2 g·L-1、聚锆比为30/1时,聚合物凝胶成胶强度达到24968 mPa·s,成胶时间约8 h,凝胶体系可维持90 d不破胶。在级差为3.9的双管驱替岩心实验中,两管的岩心分流率均接近50%,剖面改善率达到66.77%。 相似文献