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101.
102.
Ryuichi Oshima Tatsuo Wada Ju Kumanotani 《Journal of polymer science. Part A, Polymer chemistry》1984,22(9):2047-2059
The β-forming characteristics of poly(S-(2-N-carbazolylethyl)-L -cysteine), (CELC)n, were examined by infrared (IR) spectroscopy. The film of (CELC)39 cast from tetrahydrofuran (THF) showed the typical spectrum of the antiparallel β-form with the amide I band at 1630 cm?1, whereas that of (CELC)200 from dimethylformamide (DMF) or pyridine exhibited the amide I band at 1640 cm?1 which shifted to 1630 cm?1 on heating at 100°C for 5 min. As a result of the examination of the spectral variation due to the degree of polymerization, casting solvents, casting temperatures, and heat treatment, together with the evaluation of interaction constants for intermolecular hydrogen bonds, the band at 1640 cm?1 was attributed to the antiparallel-chain pleated sheet (designated as β′-form) with weaker hydrogen bond strength than that of the usual antiparallel β-form. The β′-β-transformation is discussed in terms of the rigidity of the side-chain region. 相似文献
103.
本文研究了饱和硫化钠溶液对土壤样品中硫化汞的浸取效率(其加标回收率达100%),以及用硝酸和硫化钠溶液对样品中汞的选择性浸取并研究了土壤中硫化汞垂直分布。提出了利用硝酸、饱和硫化钠溶液浸取,由冷原子荧光法选择性测定土壤及河流沉积物中硫化汞的新方法。用该方法对同一样品进行8次测定,其相对标准偏差为7.1%。 相似文献
104.
No K Bok JH Suh IH Kang SO Ko J Nam KC Kim JS 《The Journal of organic chemistry》2004,69(20):6938-6941
A series of novel tetrahomodioxacalix[4]biscrowns with crown-2, crown-3, crown-4, crown-5, and crown-6 units were synthesized. Conformations of each product are dependent on the base used and their conformation stabilities. All conformations were proven by NMR spectra and/or X-ray crystal structures. The 1,3-alternate homodioxacalix[4]biscrown-4 (4b) shows the best selectivity for K+, whereas the 1,3-alternate homodioxacalix[4]crown-5 (5) does for Cs+. Those selectivities are attributable to electrostatic interaction between the metal ion and the crown ring, as well as a pi-metal complexation. However, the C-1,2-alternate conformation does not take the metal ions regardless of the crown species as a result of steric hindrance from the methylene bridge of an ArCH2Ar unit. 相似文献
105.
The reaction of Co(NO3)2·6H2O with two equivalents of PPz (PPz = piperazine hexahydrate) and two equivalents of NH4SCN in CH3OH afforded the complex [Co(NCS)2(PPz)2(CH3OH)2]. The reaction of Ni(NO3)2·6H2O with two equivalents of PPz and four equivalents of NH4SCN in CH3OH afforded the complex [Ni(NCS)4(PPz)2]. Their IR spectra have been recorded and the structures have been determined. Crystal data for 1 : space group P&1bar;, a = 6.7208(6) Å, b = 8.4310(8) Å, c = 8.5923(8) Å, a = 77.881(2)°, β = 76.342(2)°, γ = 83.936(2)°, V = 461.75(1) Å3, Z = 1 with final residuals R1 = 0.0650 and wR2 = 0.1725. Crystal data for 2 : space group P2(1)/n, a = 7.4209(6) Å, b = 11.0231(9) Å, c = 12.317(1) Å, β = 96.642(9)°, V = 1000.9(2) Å3, Z = 2 with final residuals R1 = 0.0378 and wR2 = 0.0809. Important NCS—H‐N and O‐H—N(PPz) hydrogen‐bonding interactions in compound 1 and NCS···H‐N hydrogen‐bonding interactions and NCS—SCN interactions in compound 2 play a significant role in aligning the polymer strands in crystalline solids. 相似文献
106.
107.
K. Južnič 《Mikrochimica acta》1983,80(5-6):345-348
Summary The sorption of Ce3+ from hydrochloric acid and its chromatography on a column filled with Dowex 50 X8 was studied. The break-through volumes and elution volumes, together with the sorption profile and band broadening were determined at different temperatures and are discussed. The Chromatographic results are interpreted in terms of cerium complex formation.
Über das Verhalten von Cerium(III) in salzsaurer Lösung
Zusammenfassung Die Sorption von Ce3+ aus salzsaurer Lösung in einer mit Dowex 50 X8 gefüllten Säule sowie dessen Chromatographie wurden untersucht. Die Durchbruchs- und Elutionsvolumina wurden bestimmt und diskutiert. Die Ergebnisse wurden im Sinne einer Komplexbildung interpretiert.相似文献
108.
马心血红蛋白在氧化铟电极上的直接电子传递反应 总被引:1,自引:0,他引:1
马心血红蛋白在氧化铟电极上的直接电子传递反应杨秀娟,菊,陆天虹(中国科学院长春应用化学研究所电分析化学开放实验室,长春,130022)关键词血红蛋白,氧化铟电极,循环伏安法蛋白质与电极之间的电子转移在某种程度上类似于生物体内蛋白质分子之间的电子转移过... 相似文献
109.
A zwitterionic surfactant, dodecyldimethyl (2-hydroxy-3-sulfopropyl) ammonium (C12H25N+(CH3)2CH2CHOHCH2SO3-), named dodecyl sulfobetaine (DSB), was used as a novel modifier to coat dynamically capillary walls for capillary electrophoresis separation of basic proteins. The DSB coating suppressed the electroosmotic flow (EOF) in the pH range of 3-12. At high DSB concentration, the EOF was suppressed by more than 8.8 times. The DSB coating also prevented successfully the adsorption of cationic proteins on the capillary wall. Anions, such as Cl-, Br-, I-, SO4(2-), CO3(2-), and ClO4-, could be used as running buffer modifiers to adjust the EOF for better separation of analytes. Using this dynamically coated capillary, a mixture of eight inorganic anions achieved complete separation within 4.2 min with the efficiencies from 24,000 to 1,310,000 plates/m. In the presence of ClO4- as EOF adjustor, the separation of a mixture containing four basic proteins (lysozyme, cytochrome c, alpha-chymotrypsinogen A, and myoglobin) yielded efficiencies of 204,000-896,000 plates/m and recoveries of 88%-98%. Migration time reproducibility of these proteins was less than 0.5% relative standard deviation (RSD) from run to run and less than 3.1% RSD from day to day, showing promising application of this novel modifier in protein separation. 相似文献
110.
脱氧核糖核酸电化学传感器的原理及其应用 总被引:5,自引:0,他引:5
对电化学DNA传感器的组成及其在DNA损伤研究、环境污染监控、病原基因检测、基因疾病诊断和药物机理分析等方面的进行了总结,并对其发展趋势进行了评述。 相似文献