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11.
1-Benzopyran-4(4H)-one derivatives have been successfully employed as novel activated alkenes in the Baylis-Hillman coupling with heteroaromatic-aldehydes, nitrobenzaldehydes and isatin-derivatives and the corresponding adducts, derived from pyridine-2-carboxaldehyde, have been transformed into a novel indolizine-fused-chromone framework. 相似文献
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载银磷酸活化剑麻基活性炭纤维的抗菌性能研究 总被引:5,自引:0,他引:5
本文利用磷酸化方法,制备各种剑麻基活性炭纤维,并利用活性炭纤维的氧化还原特性及吸附性能,在其上负载金属银,研究并比较了这些载银活性炭纤维对大肠杆菌和金黄色葡萄球菌的杀灭作用,结果表明,磷酸浓度,活化方法,活化时间,纤维的比表面积等因素的均对材料的抗菌性能有一定的影响,磷酸活化的活性炭纤维表现出强的抗菌杀菌能力,高浓度磷酸活化后的纤维抗菌能力有所提高,并且抗菌能力随活化时间的延长而增加,抗菌前后纤维上负载的银未曾大量脱落,经5次抗菌试验后材料仍显示出很强的抗菌能力。 相似文献
16.
缓慢炭化部分氧化对制备煤质活性炭的影响 总被引:5,自引:0,他引:5
研究了炭化升温速度、炭化低温区引入空气部分氧化对活性炭制备过程中炭化阶段、炭化物结构、活性炭性能等的影响。结果表明,炭化时低温部分氧化可提高炭化物得率,使炭化物微晶的d002值升高和Lc值减小;而较慢的炭化升温速度有利于制备优质活性炭。缓慢炭化、部分氧化可以在一定程度上控制炭化路径,使炭化向生成取向性差、难石墨化、各向同性、呒定形炭多的炭化物的方向进行;并讨论了它们控制炭化的作用机理。以此为指导, 相似文献
17.
A new branched-pore adsorption model has been developed using an external mass transfer coefficient, K
f, an effective diffusivity, D
eff, a lumped micropore diffusion rate parameter, K
b, and the fraction of macropores, f, to describe sorption kinetic data from initial adsorbent-adsorbate contact to the long-term adsorption phase. This model has been applied to an environmental pollution problem—the removal of two dyes, Acid Blue 80 (AB80) and Acid Red 114 (AR114), by sorption on activated carbon. A computer program has been used to generate theoretical concentration-time curves and the four mass transfer kinetic parameters adjusted so that the model achieves a close fit to the experimental data. The best fit values of the parameters have been determined for different initial dye concentrations and carbon masses. Since the model is specifically applicable to fixed constant values of these four parameters, a further and key application of this project is to see if single constant values of these parameters can be used to describe all the experimental concentration-time decay curves for one dye-carbon system.The error analysis and best fit approach to modeling the decay curves for both dye systems show that the correlation between experimental and theoretical data is good for the fixed values of the four fitted parameters. A significantly better fit of the model predictions is obtained when K
f, K
b and f are maintained constant but D
eff is varied. This indicates that the surface diffusivity may vary as a function of surface coverage. 相似文献
18.
Gun'ko V. M. Mikhalovskii S. V. Melillo M. Voronin E. F. Nosach L. V. Pakhlov E. M. 《Theoretical and Experimental Chemistry》2004,40(3):137-143
The interaction of ibuprofen [2-(4-isobutylphenyl)propionic acid] with the surface of carbon and oxide adsorbents was investigated. The significant role of wide pores during the adsorption of ibuprofen on carbon adsorbents in the presence of protein molecules was demonstrated. At low concentrations ibuprofen is adsorbed on the surface of hydrophilic and hydrophobic adsorbents in the form of a monomer, but the contribution from the adsorbed dimer increases with increase in its concentration. 相似文献
19.
Svetlana B. Lyubchik Irene I. Perepichka Olga L. Galushko Andrey I. Lyubchik Elena S. Lygina Isabel M. Fonseca 《Adsorption》2005,11(5-6):581-593
In order to understand the patterns of the adsorption equilibrium of Cr (III) on activated carbon, the adsorption process
was studied by two different ways: classical batch experiments on commercial Norit and Merck activated carbons and their oxidized
forms in a wide range of pHs; and extended time-based tests at the same pH values on the same adsorbents. This approach allowed
us to understand the role of texture, chemical carbon surface functionality and experimental conditions (initial pH of the
solution, contact time and adsorbate/adsorbent ratio) on the effectiveness of Cr (III) removal. The adsorption process of
Cr (III) at (24 ± 1∘C) on Merck and Norit activated carbons and their oxidized forms were studied at pH values between 1.5 and 5 (either adjusted
or buffered). Chromium concentration was fixed at 200 ppm. The carbon loading ranged from 1.2 to 20 g/l. The carbon/Cr (III)
solution contact time was varied from 0.5–1 month to 5 months, to ensure that the saturation of the carbon level was reached.
According to the data obtained, the presence of carboxylic groups on carbon surface seems to enhance Cr (III) uptake at initial
pH of the solution in the range between 2 and 4. Depending on the nature of the adsorbent surface chemistry, the contact time
to reach equilibrium may range from 3 to 5 months. There is an optimum carbon loading which limits the Cr (III) uptake/removal
at given pH value. In order to understand the adsorption process, an ion exchange, surface complex and surface precipitation
were considered.
This paper was presented in the 5th Brazilian Meeting on Adsorption, held at Natal, Brazil, 18-21 July, 2004. 相似文献
20.
杂多酸在活性炭上的固载化Ⅲ.活性炭在酸性介质中对钨硅杂多酸(SiW_(12))的吸附 总被引:1,自引:0,他引:1
在氢离子浓度均为3mol/L的硫酸,盐酸,磷酸,醋酸水溶液中和冰醋酸中研究了具有Keggin结构的硅钨杂多酸(SiW_(12))在不同来源活性炭上的吸附作用。各活性炭对SiW_(12)吸附等温线的形式是不相同的,吸附剂载体的微孔结构以及杂多酸的溶剂化起着重要的作用。并且在无机酸介质中,杂多酸的吸附量比在水溶液中成规律性地增加,且与酸强度成正比关系。在有机酸介质中,吸附作用比较复杂。根据所得结果,提出了在酸性介质中杂多酸在活性炭表面的吸附模型。 相似文献