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21.
Coating Carbon Nanotubes with Europium Oxide   总被引:4,自引:0,他引:4  
Carbon nanotubes (CNTS) coating with europium oxide by a simple method is reported in this letter for the first time. The CNTS were refluxed in a solution of nitric acid containing europium nitrate, and the pH value was subsequently ajusted with ammonia solution. At last, the mixture was filtered and annealed. The TEM micrograph showed that the CNTS were covered with a uniform thin layer with thickness of about 15 nm. The XRD results revealed that the CNTS were coated with europium oxide.  相似文献   
22.
1,4-二乙氧基苯的相转移催化合成   总被引:1,自引:0,他引:1  
采用大孔型交联聚苯乙烯为载体研究制得新型季Lin盐型相转移催化剂Y98B,并将其于1,4-二乙氧基苯的催化合成反应,进行了产品的红外光谱分析和熔点测定,探讨了催化剂用量、对苯二酚与溴乙烷物的质量比、反应温度和反应时间等动力学条件对产品收率的影响。确定了在反应温度为70℃,mol对苯二酚:mol溴乙烷=1:3.5,反应时间4h,催化剂用量3.0g的条件下产品收率可达84.3%。  相似文献   
23.
A method of tracking ensembles of particle images   总被引:8,自引:4,他引:4  
A method for tracking ensembles of particle images of a digital PIV record by making use of the minimum quadratic difference (MQD) technique is described. The similarity of this method with correlation schemes used for the evaluation of PIV is discussed. The method is exemplified with two applications that are also evaluated by auto- and cross-correlation, respectively.Receipt of a fellowship from Deutscher Akademischer Austauschdienst (DAAD) for L. C. Gui is gratefully acknowledged.  相似文献   
24.
A New Reaction-controlled Phase-transfer Catalyst System   总被引:1,自引:0,他引:1  
A new reaction-controlled phase-transfer catalyst system was designed and synthesized.In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxidant. The conversion of H2O2 was 100% and the yield of cyclohexene oxide was 87.1% based on cyclohexene. Infrared spectra showed that both fresh catalyst and the recovered catalyst do have completely same absorption peak, indicating the structure of catalyst is very stability and can be recycled.  相似文献   
25.
Fe(OH)2悬浮液在EDTA作用下氧气氧化生成δ-FeOOH的机理研究   总被引:1,自引:0,他引:1  
At room temperature and in the presence of trace EDTA, the formation of δ-FeOOH was studied by the rapid oxidation of Fe(OH)2 suspension with O2. The structural and morphological changes were characterized by various techniques such as XRD, FTIR and TEM. γ-FeOOH and (δ-FeOOH) formed simutaneously in the early period of oxidation. But as the rate of mass transfer was in equilibrium, trace (γ-FeOOH) vanished gradually. Accordingly, pure phase δ-FeOOH was obtained. At the same time, critical amount ratio K of EDTA to Fe2+ was verified. The experiments show that the reactivity, rate of the oxidizing agent and pH of the initial medium were important factors for the formation of pure phase (δ-FeOOH). Under the auxiliary effect of EDTA, the reactivity of O2 was nearly improved to that of H2O2. And the process of the oxidation that Fe(OH)2 suspension was oxidized by O2 under that condition was discussed.  相似文献   
26.
本文报道了腺嘌呤存在时对超氧化物歧化酶在金丝电极上电化学行为的影响。并从电化学石英晶体微天平技术的测量结果,初步讨论了腺嘌呤对促进超氧化物歧化酶电子传递过程的作用机制。  相似文献   
27.
In this paper, perovskite oxide SmCoO3 was prepared by the solid-state reaction method using Co2O3 and Sm2O3 as raw materials. The structure and properties of the samples were investigated by XRD, Raman spectral techniques, and DC measurements and so on. The results of XRD and Raman spectra showed that the mixtures of Co2O3 and Sm2O3 can react to produce a single phase perovskite oxide SmCoO3 around 1353 K. The single-phase SmCoO3 changes from an insulator to a semi-conductor and transition occurs around 470 K. The thermal expansion coefficient (2.17 × 10−5 K−1) of the single-phase SmCoO3 is approximately equal to that of doped LaGaO3, but much bigger than that of SDC(Ce0.85Sm0.15O2) above 873 K.  相似文献   
28.
辣根过氧化物酶对心肌线粒体过氧化损伤的保护作用   总被引:1,自引:0,他引:1  
邢晖  冯雁 《高等学校化学学报》1997,18(10):1628-1632
以黄嘌呤氧化酶/次黄嘌呤自由基诱生系统建立了稳定的离体心肌线粒体的损伤模型,并应用此模型研究辣根过氧化物酶对心肌线粒体自由基氧化损伤的保护作用,结果表明,辣根过氧化物酶能抑制心肌线粒体中氧自由基的形成,降低膜脂的过氧水平,保护了线粒体膜酶活性,有效地防止自由基对线粒体结构和功能的损伤。  相似文献   
29.
Removal of end6toxin from medicine injection is very important, becauseendotoxin withpotential biological activity causes pyrogenic and shock reactions in' mammals-'on...intravenous injection even as law as "an6gram amounts. Endotoxin, a constituent ofpotential contaminant of physiological fluids and aqueous solutions 'and very stable atextreme temperature and PH values. For removing endotoxin from solutions ofbiomolecules, such as HSA, adsorption techniques are usedl.' Many methods forendot…  相似文献   
30.
反相液相色谱用球形共聚物柱填料   总被引:2,自引:0,他引:2  
采用新颖聚合工艺制备用于反相高效液相色谱柱填料的乙基苯乙烯-二乙烯苯球形共聚物,不需使用备有高速搅拌的混匀器和特殊的筛析设备,聚合物粒径的95%在3~7μm之间,测算了渗透性、柱效和峰不对称性等柱参数,并通过分离实例说明该填料对胺类、酚类和芳烃类具有优良分离性能。  相似文献   
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