This article discussed the benzoic acid activated carbons which have changed the types and content of acid oxygen-function groups on the surface of activated carbons and their effect on the adsorption for Hg^0 in simu...This article discussed the benzoic acid activated carbons which have changed the types and content of acid oxygen-function groups on the surface of activated carbons and their effect on the adsorption for Hg^0 in simulated flue gas at 140 ℃. These surface acid oxygen function groups were identified by Boehm titration, Fourier transformation infrared spectrum, temperature programmed desorption and X-ray photoelectron spectroscopy. It indicates that the carboxyl, lactone and phenolic were formed when the benzoic acid is loaded on the surface of activated carbons. Among the surface acid oxygen function groups, the carboxyl groups enhance the adsorption capacities of Hg^0 for activated carbons to a greater extent.展开更多
A new zinc acetate catalyst which was prepared from modified activated carbon exhibited extreme activity towards the synthesis of vinyl acetate. The activated carbon was modified by nitric acid, vitriol and peroxyacet...A new zinc acetate catalyst which was prepared from modified activated carbon exhibited extreme activity towards the synthesis of vinyl acetate. The activated carbon was modified by nitric acid, vitriol and peroxyacetic acid （PAA）. The effect on specific area, structure, pH and surface acidity groups of carders by modification was discussed. Amount of carbonyl and carboxyl groups in activated carbon was increased by peroxyacetic acid treatment. The productivity of the new catalyst was 14.58% higher than that of catalyst prepared using untreated activated carbon. The relationship between amount of carbonyl and carboxyl groups （m） and catalyst productivity （P） was P = 1.83 ＋ 2.26 × 10^-3＊e^3.17m. Reaction mechanism was proposed. C 2009 Liang Rong Feng. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Abstract Objective To conduct a screening survey of glycophorin (GP) variants and observe the content changes of sialic acid (SA) and total sulfhydryl (SH) groups on the erythrocyte membranes among residents in a...Abstract Objective To conduct a screening survey of glycophorin (GP) variants and observe the content changes of sialic acid (SA) and total sulfhydryl (SH) groups on the erythrocyte membranes among residents in a tertian malaria hyperendemic area of Guizhou Province. Methods GP variants were detected in the erythrocyte hemolysates of 173 local residents at two villages of Libo County by SDS PAGE on 10% to 15% gradients gel and Western immunoblotting. Their SA and total SH group contents were estimated in erythrocyte membranes by spectrophotometric methods. 114 healthy subjects in Changsha and 49 individuals at a neighbouring village of the above area showing low morbidity of malaria served as normal and endemic controls respectively. Results Three distinct types of GP variants were found among 19 propositi in this hyperendemic area. The incidence of GP variants was 7.9% (8/101) at Yaolu Village whose population was mainly composed of Yao ethnic group;while that of Buyi ethnic group at Maolan Village was higher (15.3%; 11/72).The erythrocyte membrane contents of SA in residents at both villages exhibited a very significant tendency of decline (P<0.01), whereas those of total SH groups increased prominently in residents of Yaolu Village only (P<0.05). Conclusions The frequency of GP variants in this hyperendemic area does not depend upon the severity of malarial prevalence. The evident reduction of SA contents in the residents may be related to the breaking down of the SA residues on membrane GPs by the invasion of Plasmodium vivax.展开更多
半导体产业是支撑经济社会发展和保障国家安全的基础性、战略性和先导性产业,单晶硅由于具有独特的物理及化学性质,在半导体产业中占有重要的地位,多晶硅作为制备单晶硅的前驱体,对纯度的要求尤为严苛,因此本文研究了一种采用低成本混...半导体产业是支撑经济社会发展和保障国家安全的基础性、战略性和先导性产业,单晶硅由于具有独特的物理及化学性质,在半导体产业中占有重要的地位,多晶硅作为制备单晶硅的前驱体,对纯度的要求尤为严苛,因此本文研究了一种采用低成本混酸清洗多晶硅块,进而制备高纯多晶硅的新型方法。在室温环境中,采用纯度为电子级(EL)、超纯(UP)、超纯MOS(UP-S)级的由氢氟酸和硝酸组成的混酸溶液清洗多晶硅块,所得多晶硅表面金属含量均在2 ppbw以下,即符合半导体级多晶硅对表面金属含量的要求;并研究了多晶硅表面金属含量与清洗过程所消耗EL级混酸之间的关系,发现使用300 ml V_(HF):V_(HNO3)=1:10的由氢氟酸和硝酸组成的EL级混酸溶液可以清洗出3.33kg半导体级多晶硅,说明低成本EL级混酸也可以广泛用于半导体级多晶硅的工业生产中。展开更多
文摘This article discussed the benzoic acid activated carbons which have changed the types and content of acid oxygen-function groups on the surface of activated carbons and their effect on the adsorption for Hg^0 in simulated flue gas at 140 ℃. These surface acid oxygen function groups were identified by Boehm titration, Fourier transformation infrared spectrum, temperature programmed desorption and X-ray photoelectron spectroscopy. It indicates that the carboxyl, lactone and phenolic were formed when the benzoic acid is loaded on the surface of activated carbons. Among the surface acid oxygen function groups, the carboxyl groups enhance the adsorption capacities of Hg^0 for activated carbons to a greater extent.
文摘A new zinc acetate catalyst which was prepared from modified activated carbon exhibited extreme activity towards the synthesis of vinyl acetate. The activated carbon was modified by nitric acid, vitriol and peroxyacetic acid （PAA）. The effect on specific area, structure, pH and surface acidity groups of carders by modification was discussed. Amount of carbonyl and carboxyl groups in activated carbon was increased by peroxyacetic acid treatment. The productivity of the new catalyst was 14.58% higher than that of catalyst prepared using untreated activated carbon. The relationship between amount of carbonyl and carboxyl groups （m） and catalyst productivity （P） was P = 1.83 ＋ 2.26 × 10^-3＊e^3.17m. Reaction mechanism was proposed. C 2009 Liang Rong Feng. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘Abstract Objective To conduct a screening survey of glycophorin (GP) variants and observe the content changes of sialic acid (SA) and total sulfhydryl (SH) groups on the erythrocyte membranes among residents in a tertian malaria hyperendemic area of Guizhou Province. Methods GP variants were detected in the erythrocyte hemolysates of 173 local residents at two villages of Libo County by SDS PAGE on 10% to 15% gradients gel and Western immunoblotting. Their SA and total SH group contents were estimated in erythrocyte membranes by spectrophotometric methods. 114 healthy subjects in Changsha and 49 individuals at a neighbouring village of the above area showing low morbidity of malaria served as normal and endemic controls respectively. Results Three distinct types of GP variants were found among 19 propositi in this hyperendemic area. The incidence of GP variants was 7.9% (8/101) at Yaolu Village whose population was mainly composed of Yao ethnic group;while that of Buyi ethnic group at Maolan Village was higher (15.3%; 11/72).The erythrocyte membrane contents of SA in residents at both villages exhibited a very significant tendency of decline (P<0.01), whereas those of total SH groups increased prominently in residents of Yaolu Village only (P<0.05). Conclusions The frequency of GP variants in this hyperendemic area does not depend upon the severity of malarial prevalence. The evident reduction of SA contents in the residents may be related to the breaking down of the SA residues on membrane GPs by the invasion of Plasmodium vivax.
文摘半导体产业是支撑经济社会发展和保障国家安全的基础性、战略性和先导性产业,单晶硅由于具有独特的物理及化学性质,在半导体产业中占有重要的地位,多晶硅作为制备单晶硅的前驱体,对纯度的要求尤为严苛,因此本文研究了一种采用低成本混酸清洗多晶硅块,进而制备高纯多晶硅的新型方法。在室温环境中,采用纯度为电子级(EL)、超纯(UP)、超纯MOS(UP-S)级的由氢氟酸和硝酸组成的混酸溶液清洗多晶硅块,所得多晶硅表面金属含量均在2 ppbw以下,即符合半导体级多晶硅对表面金属含量的要求;并研究了多晶硅表面金属含量与清洗过程所消耗EL级混酸之间的关系,发现使用300 ml V_(HF):V_(HNO3)=1:10的由氢氟酸和硝酸组成的EL级混酸溶液可以清洗出3.33kg半导体级多晶硅,说明低成本EL级混酸也可以广泛用于半导体级多晶硅的工业生产中。
基金supported by the National Natural Science Foundation of China(20976077,21076100)National Key Basic Research Program of China(973)(2007CB216403)Innovation Team of Liaoning Province Colleges,China~~
