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61.
应用核磁共振和电子自旋共振技术研究了铜锌超氧化物歧化酶(CuZnSOD)的金属重组酶与水溶液中游离组氨酸(His)的相互作用。发现在水溶液中CuZnSOD的金属重组酶活性中心的金属可与加入的His发生作用而被部分地诱导出来,与His形成络合物。 相似文献
62.
A novel route for waste water treatment: photo-assisted Fenton degradation of dye pollutants accumulated in natural polyelectrolyte microshells 总被引:2,自引:0,他引:2
The efficient accumulation of dyes in constructed natural polyelectrolyte microshells under moderate conditions, combined with the photo-assisted Fenton reagent, opens a new route for the effective elimination of dye pollutants from waste water. 相似文献
63.
64.
用峰鉴别技术反相高效液相色谱法测定火锅汤料中微量吗啡 总被引:3,自引:0,他引:3
本文报道了以峰鉴别技术为定性依据的测定火锅汤料中微量吗啡的反相高效液相色谱法。本法采用改良的Stas-otto法分离提取复杂样品中的微量吗啡。由于采用峰鉴别技术,增加了定性参数,大大提高了定性方法的准确性。本法简便、快速。最低检出浓度为0.04mg/L。在数十例样品分析中,与其它仪器分析结果比照,非常符合。 相似文献
65.
The ESR signals of bilirubin-IXα were studied including the samples treated with free radical generating and inhibiting systems, i.e.X-X0., Fe/EDTA, SOD, mannitol/ascorbate, DTPA, KCN et al.These stable signals all comprise those originated from a semiquinone radical(g=2.0012)and superoxide radical(g11=2.041, g⊥=2.0040).The latter is shown to be bound with metal ionsespecially iron, chelated by bilirubin.The iron probably comes from bilirubin precursor---hemootobin.Active oxygen free radical scavengers may destroy these radicals.Kinetic curves of regeneration of the bilirubin radicals have been determined.Bilirubin is discussed as"active oxygen trap"in mammatians. 相似文献
66.
InteractionbetweenMetalinMetalloEnzymeandSmallBiologicalMolecules¥HuJie-Han;ShuZan-Yong;TaoLi-Mei;ChengGuo-Bao(DalianInstitut... 相似文献
67.
The anomaly of specific heat in systems out of equilibrium, especially the measurement procedure dependence of specific heat, is investigated by means of free energy landscape. Introducing measurement procedure which is based on experimental method, we propose a calculation method of specific heat in systems out of equilibrium and find an abrupt change in specific heat between annealed and quenched states. For longer observation time the change in specific heat occurs at lower temperature and becomes sharper. For slower cooling of a system the transition temperature becomes lower. This cooling rate dependence of the transition temperature is consistent with experiments and thus the abrupt change in specific heat can be regarded as the glass transition which is thermally identified. 相似文献
68.
A molecular level understanding of the photoreactivity of self-assembled monolayers (SAMs) becomes increasingly important as the spatial resolution starts to be limited by the size of the resist and the spatial extent of the photochemical reactions in photoresist micropatterning. To this end, a number of surface characterization techniques were combined to understand the reactive agents, reactive sites, kinetics, and reaction pathways in the UV photoreactivity of octadecylsiloxane (ODS) SAMs. Quantitative analysis of our results provides evidence that ground state atomic oxygen is the primary reactive agent for the UV degradation of ODS SAMs. UV degradation, which follows zero-order kinetics, results in the scission of alkyl chains instead of the siloxane headgroups. Our results suggest that the top of the ODS SAMs is the preferential reactive site. Using a novel, highly surface sensitive technique, fluorescence labeling of surface species, we identified the presence of submonolayer quantities chemical functional groups formed by the UV degradation. These groups are intermediates in a proposed mechanism based on hydrogen abstraction. 相似文献
69.
Norikazu Nishiyama Yong-Rong Dong Tao Zheng Yasuyuki Egashira Korekazu Ueyama 《Journal of membrane science》2006,280(1-2):603-609
Microporous carbon membranes were prepared on an -alumina support by a pyrolysis of cationic tertiary amine/anionic polymer composites. The precursor solutions contain a thermosetting resorcinol/formaldehyde (RF) polymer and a cationic tertiary amine. Three types of cationic tertiary amines with different chain lengths were used, such as tetramethlammonium bromide (TMAB), tetrapropylammonium bromide (TPAB) and cetyltrimethylammonium bromide (CTAB). A porous structure was produced by a decomposition of the amine and the resulting pores assisted the further gasification of the RF polymer at high temperature. The carbon/alumina membranes have thin and continuous carbon top layers with a thickness of 1 μm. Gas permeation tests were performed using single gases of CO2, O2, N2, CF4, n-C4H10 and i-C4H10, as well as binary mixtures of CH4/n-C4H10 and N2/CF4 at different temperatures between 23 and 150 °C. The carbon membrane prepared using TMAB showed separation factors higher than 650 for the CH4/n-C4H10 mixtures and higher than 8100 for the N2/CF4 mixture. From the permeation of pure gases with different molecular sizes, the pore sizes of the carbon membrane prepared using TMAB, TPAB and CTAB are estimated to be 4.0, 5.0 and larger than 5.5 Å, respectively, indicating that the micropore size of the carbon membranes is controllable by using different amines. 相似文献
70.
Kang De Yao Tao Peng Han Bao Feng Yu Ying He 《Journal of polymer science. Part A, Polymer chemistry》1994,32(7):1213-1223
The aqueous swelling kinetics of a series of crosslinked chitosan (cr-CS) with glutaraldehyde (GA) interpenetrating polyether hydrogels have been studied as functions of pH, the N-deacetylation degree of chitosan, the amount of crosslinking agent, the electrolyte composition in solution, temperature, and gel composition. Based on these results, the swelling mechanism of the hydrogels was discussed. The release profiles of chlorhexidini acetas from the semi-IPN were also investigated. © 1994 John Wiley & Sons, Inc. 相似文献