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Formaldehyde degradation by UV/TiO_2/O_3 process using continuous flow mode 认领 引用 被引量：12
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作者 QI Hong SUN De-zhi CHI Guo-qing 《Journal of Environmental Sciences》 SCIE EI CAS 2007年第9期1136-1140,共5页
The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount... The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount on degradation of formaldehyde gas were investigated. The experimental results indicated that the combination of ozonation with photocatalytic oxidation on the degradation of formaldehyde showed a synergetic action, e.g,, it could considerably increase decomposing of formaldehyde. The degradation efficiency of formaldehyde was between 73.6% and 79.4% while the initial concentration in the range of 1.84--24 mg/m^3 by O3/TiO2flJV process. The optimal humidity was about 50% in UV/TiO2/O3 processs and degradation of formaldehyde increases from 39.0% to 94.1% when the ozone content increased from 0 to 141 mg/m^3. Furthermore, the kinetics of formaldehyde degradation reaction could be described by Langmuir-Hinshelwood model. The rate constant k of 46.72 mg/（m^3.min） and Langmuir adsorption coefficient K of 0.0268 m^3/mg were obtained. 展开更多
关键词 UV/TiO2/O3 process formaldehyde continuous flow mode
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Comparison of degradation reactions of Acid Yellow 61 in both oxidation processes of H_2O_2/UV and O_3 认领 引用
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作者 WANG Yi zhong 1, A.Yedeler 2, A. Kettrup 2(1 Research Center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China 2 GSF Institute of Ecological Chemistry, Neuherberg, Postfach 1129, 85758 Neuherberg, Germany) 《Journal of Environmental Sciences》 SCIE EI CAS 2001年第3期304-310,共7页
The comparison of degradation of Acid Yellow 61 as a model dye compound in both oxidation processes of H 2O 2/UV and O 3 has been studied. When the decolorization rate of Acid Yellow 61 in both reactions presented sim... The comparison of degradation of Acid Yellow 61 as a model dye compound in both oxidation processes of H 2O 2/UV and O 3 has been studied. When the decolorization rate of Acid Yellow 61 in both reactions presented similar, it was found there are some differences from the results of AOX removal and production of inorganic ions and organic acids. The results reveal that the H 2O 2/UV has beneficial effect on mineralization than O 3 only for degradation of Acid Yellow 61 solution and it is possible for enhancement of method efficiency by taking longer reaction time and addition of high concentration of oxidants. 展开更多
关键词 oxidation process H 2O 2/UV O 3 dye compound
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US/O_3/TiO_2/UV氧化处理苯胺废水实验研究 认领 引用 被引量：8
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作者 香杰新 张赵田 +1 位作者 范洪波 吕斯濠 《环境科学与技术》 CAS 北大核心 2010年第12期81-85,共5页
实验采用US/O3/TiO2/UV氧化技术处理模拟苯胺废水,考察了各种技术组合对苯胺废水的处理效果以及技术组合的影响因素。结果表明,US单独使用对苯胺废水的处理效果较差,需要与其它技术联用;纳米TiO2/UV对苯胺废水的降解速度较慢,停留时间... 实验采用US/O3/TiO2/UV氧化技术处理模拟苯胺废水,考察了各种技术组合对苯胺废水的处理效果以及技术组合的影响因素。结果表明,US单独使用对苯胺废水的处理效果较差,需要与其它技术联用;纳米TiO2/UV对苯胺废水的降解速度较慢,停留时间需保证纳米TiO2与废水污染物的充分接触,并且需要对纳米TiO2膜及技术参数进行优化以保证光催化的效果;技术组合中有O3时,COD的去除率有很大的提高;比较而言,US/O3/TiO2/UV技术组合对苯胺废水的处理效果最好。采用US/O3/TiO2/UV技术处理苯胺废水时,苯胺废水浓度的增加会导致COD去除率下降;废水pH值的增加会导致COD去除率轻微下降;随反应的进行,废水pH值会向4～6的区间靠拢;臭氧浓度要适中,过大或过小均会导致处理效率的下降;在优化条件下,该技术组合处理苯胺废水20min时的COD去除率达85%以上,60min时则达到96%。 展开更多
关键词 US O3 TiO2/UV 高级氧化 苯胺
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Fe_3O_4/TiO_2@生物碳骨架复合材料的一步法制备及UV-Fenton催化性能 认领 引用 被引量：11
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作者 于晓丹 林鑫辰 +1 位作者 冯威 李伟光 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2018年第11期2500-2506,共7页
以玉米秸秆为生物模板,经铁盐和钛盐溶液浸渍后煅烧,制备了新型Fe_3O_4/TiO_2分层介孔玉米秸秆碳骨架复合材料(Fe_3O_4/TiO_2@MSC),并研究了其多相UV-Fenton体系降解四环素的效能.利用X射线衍射(XRD)、X射线光电子能谱(XPS)、N2吸附-脱... 以玉米秸秆为生物模板,经铁盐和钛盐溶液浸渍后煅烧,制备了新型Fe_3O_4/TiO_2分层介孔玉米秸秆碳骨架复合材料(Fe_3O_4/TiO_2@MSC),并研究了其多相UV-Fenton体系降解四环素的效能.利用X射线衍射(XRD)、X射线光电子能谱(XPS)、N2吸附-脱附、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对合成的催化剂进行了表征.结果表明,Fe_3O_4/TiO_2@MSC保留了玉米秸秆的分级多孔形态,纳米Fe_3O_4和TiO_2在MSC表面生长,秸秆碳作为骨架提高了纳米Fe_3O_4的分散性,防止其团聚,提高了催化剂的稳定性,并且能够增加材料的比表面积和活性点位,进而增强对UV-Fenton体系的催化活性. TiO_2光催化和多相Fenton体系的协同作用促进了Fe(Ⅲ)向Fe(Ⅱ)转化.催化性能研究结果表明,在相同条件下,Fe_3O_4/TiO_2@MSC催化的多相UV-Fenton体系盐酸四环素(TCH)降解效率在反应40 min后达到99. 8%,远高于Fe_3O_4@MSC+H2O_2(30%),UV+H2O_2(73%)、UV+Fe_3O_4@MSC+H2O_2(89. 1%)和UV+Fe_3O_4/TiO_2+H2O_2(89. 2%)体系,并且该体系在中性甚至碱性条件下均能达到满意的TCH去除效果. 展开更多
关键词 Fe3O4/TiO2@MSC 玉米秸秆碳骨架 UV-Fenton体系 盐酸四环素
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Effects of UV/Ag-TiO2/O3advanced oxidation on unicellular green alga Dunaliella salina:Implications for removal of invasive species from ballast water 认领 引用 被引量：6
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作者 Donghai Wu Hong You +2 位作者 Jiaxuan Du Chuan Chen Darui Jin 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第3期513-519,共7页
The UV/Ag-TiO2/O3process was investigated for ballast water treatment using Dunaliella salina as an indicator.Inactivation curves were obtained,and the toxicity of effluent was determined.Compared with individua... The UV/Ag-TiO2/O3process was investigated for ballast water treatment using Dunaliella salina as an indicator.Inactivation curves were obtained,and the toxicity of effluent was determined.Compared with individual unit processes using ozone or UV/Ag-TiO2,the inactivation efficiency ofD.salina by the combined UV/Ag-TiO2/O3 process was enhanced.The presence of ozone caused an immediate decrease in chlorophyll a(chl-a)concentration.Inactivation efficiency and chl-a removal efficiency were positively correlated with ozone dose and ultraviolet intensity.The initial total residual oxidant(TRO)concentration of effluent increased with increasing ozone dose,and persistence of TRO resulted in an extended period of toxicity.The results suggest that UV/Ag-TiO2/O3 has potential for ballast water treatment. 展开更多
关键词 ballast water UV/Ag-TiO2/O3process Dunaliella salina inactivation total residual oxidant
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Influence of refining process and utilization of different slags on inclusions, titanium yield and total oxygen content of Ti-stabilized 321 stainless steel 认领 引用 被引量：5
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作者 Xing-run Chen Guo-guang Cheng +2 位作者 Yu-yang Hou Jing-yu Li Ji-xiang Pan 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2020年第8期913-921,共9页
Ti-stabilized 321 stainless steel was prepared using an electric arc furnace, argon oxygen decarburization (AOD) furnace, ladle furnace (LF), and continuous casting processes. In addition, the effect of refining proce... Ti-stabilized 321 stainless steel was prepared using an electric arc furnace, argon oxygen decarburization (AOD) furnace, ladle furnace (LF), and continuous casting processes. In addition, the effect of refining process and utilization of different slags on the evolution of inclusions, titanium yield, and oxygen content was systematically investigated by experimental and thermodynamic analysis. The results reveal that the total oxygen content (TO) and inclusion density decreased during the refining process. The spherical CaO–SiO2–Al2O3–MgO inclusions existed in the 321 stainless steel after the AOD process. Moreover, prior to the Ti addition, the spherical CaO–Al2O3–MgO–SiO2 inclusions were observed during LF refining pro-cess. However, Ti addition resulted in multilayer CaO–Al2O3–MgO–TiOx inclusions. Two different samples were prepared by conventional CaO–Al2O3-based slag (Heat-1) and -TiO2-rich CaO–Al2O3-based slag (Heat-2). The statistical analysis revealed that the density of inclusions and the -TiOx content in CaO–Al2O3–MgO–TiOx inclusions found in Heat-2 sample are much lower than those in the Heat-1 sample. Furthermore, the TO content and Ti yield during the LF refining process were controlled by using -TiO2-rich calcium aluminate synthetic slag. These results were consistent with the ion–molecule coexist-ence theory and FactSage?7.2 software calculations. When -TiO2-rich CaO–Al2O3-based slag was used, the -TiO2 activity of the slag increased, and the equilibrium oxygen content significantly decreased from the AOD to LF processes. Therefore, the higher -TiO2 activity of slag and lower equilibrium oxygen content suppressed the undesirable reactions between Ti and O. 展开更多
关键词 321 Austenitic stainless steel Oxygen content Inclusion TiO2-rich CaO–Al2O3-based slag Ladle furnace(LF)refining process Ion–molecule coexistence theory
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Hot deformation and processing maps of Al_2O_3/Al composites fabricated by flake powder metallurgy 认领 引用 被引量：2
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作者 栾佰峰 邱日盛 +4 位作者 李春红 杨晓芳 李志强 张荻 刘庆 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第4期1056-1063,共8页
The deformation behaviors of Al2O3/Al composites were investigated by compressive tests conducted at temperature of 300-450 °C and strain rates of 0.001-1.0 s-1 with Gleeble-1500 D thermal simulator system. The r... The deformation behaviors of Al2O3/Al composites were investigated by compressive tests conducted at temperature of 300-450 °C and strain rates of 0.001-1.0 s-1 with Gleeble-1500 D thermal simulator system. The results show that the flow stress increases with increasing strain rate and decreasing temperature. The hyperbolic sine constitutive equation can describe the flow stress behavior of Al2O3/Al composites, and the deformation activation energy and constitutive equations were calculated. The processing maps of Al2O3/Al-2 μm and Al2O3/Al-1 μm composites at strain of 0.6 were obtained and the optimum processing domains are in ranges of 300-330 °C, 0.007-0.03 s-1 and 335-360 °C, 0.015-0.06 s-1 for hot working, respectively. The instability zones of flow behavior can also be recognized by the maps. 展开更多
关键词 Al2O3/Al composites flake powder metallurgy flow stress processing map
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Effects of Nitrogen Application on N_2O Flux from Fluvo-Aquic Soil Subject to Freezing-Thawing Process 认领 引用 被引量：3
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作者 WANG Feng GAO Shang-bin +4 位作者 ZHANG Ke-qiang LI Hai-bo BAI Li-jing HUANG Zhi-ping MI Chang-hong 《Agricultural Sciences in China》 2010年第4期577-582,共6页
A lab-incubation experiment was conducted to investigate the effects of different forms of nitrogen application （ammonium, NH4＋-N; nitrate, NO3--N; and amide-N, NH2-N） and different concentrations （40, 200 and 800... A lab-incubation experiment was conducted to investigate the effects of different forms of nitrogen application （ammonium, NH4＋-N; nitrate, NO3--N; and amide-N, NH2-N） and different concentrations （40, 200 and 800 mg L-1） on N2O emission from the fluvo-aquic soil subjected to a freezing-thawing cycling. N2O emission sharply decreased at the start of soil freezing, and then showed a smooth line with soil freezing. In subject to soil thawing, N2O emission increased and reached a peak at the initial thawing stage. The average N2O emissions with addition of NH4＋-N, NO3 -N and NH2-N are 119.01, 611.61 and 148. 22 ug m-2 h-1, respectively, at the concentration of 40 mg L-1; 205.28, 1 084.40 and 106.13 ug m2 h-1 at the concentration of 200 mg L-1; and 693.95, 1 820.02 and 49.74 ug m-2 h4 at the concentration of 800 mg L-1. The control is only 100.35 ug m-2 h-1. N2O emissions with addition of NH4＋-N and NO3--N increased with increasing concentration, by ranging from 17.49 to 425.67% for NH4＋-N, and from 563.38 to 1458.6% for NO3--N compared with control. There was a timelag for N2O emission to reach a steady state with an increase of concentration. In contrast, by adding NH2-N to soil, N2O emission decreased with increasing concentration. In sum, NH4＋-N or NO3--N fertilizer incorporated in soil enhanced the cumulative N2O emission from the fluvo-aquic soil relative to amide-N. This study suggested that ammonium and nitrate concentration in overwintering water should be less than 200 and 40 mg L-1 in order to reduce N2O emissions from soil, regardless of amide-N. 展开更多
关键词 freezing-thawing process NH4＋ -N NO3--N amide-N N2O flux
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Influence of coexisting substances on the photodegradation behaviors of 17α-ethinylestradiol (EE_2) in the UV/H_2O_2 process 认领 引用 被引量：1
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作者 张照韩 冯玉杰 +2 位作者 王鲁 刘雨 任南琪 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第5期31-36,共6页
The batch photodegradation reactor was used to investigate the influence of the common coexisting substances in wastewater,such as H+,anions (HCO3-,Cl-and NO3-) and organic compounds (methanol and bisphenol A),on the ... The batch photodegradation reactor was used to investigate the influence of the common coexisting substances in wastewater,such as H+,anions (HCO3-,Cl-and NO3-) and organic compounds (methanol and bisphenol A),on the photodegradation behaviors of EE2 in the UV/H2O2 process.The results indicated that the addition of coexisting substances can influence the photodegradation behaviors of EE2 and it also follows the first-order kinetics.The acidic (pH 2-4) and alkaline (pH 10-12) medium benefit the photodegradation of EE2,but the photodegradation rate constant of EE2 keeps almost constant in the pH value of 4-10.The addition of anions,such as HCO3-,Cl-and NO3-,can inhibit the photodegradation of EE2,and the rate constant has a negative linear relationship with the concentration of the anions.However,the reduction degrees vary with the anions kinds,and the inhibition effect of the three anions is in the order of HCO3->NO3->Cl-.Addition of 5 mg/L methanol and bisphenol A can reduce the photodegradation rate constant of EE2by 84.31% and 72%,respectively.By comparison,the retardant effect of methanol is much more evident.In the studied concentrations range,the photodegradation rate constant of EE2 is the unary quadratic function of the organic compounds concentrations. 展开更多
关键词 EE2 Anions Coexisting organic compounds UV/H2O2 process Photodegradation rate constant
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Preparation of Spherical Bi_2O_3 Powder by Plasma and Precipitation Processes 认领 引用 被引量：1
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作者 陈培荣 季幼章 冯士芬 《Plasma Science and Technology》 SCIE EI CAS 2005年第6期3139-3142,共4页
Spherical Bi2O3 powder prepared by plasma chemical vapor reaction and aqueous chemical precipitation is studied. The superfine spherical Bi2O3 powder with an average diameter of 1 μm is made by plasma process. During... Spherical Bi2O3 powder prepared by plasma chemical vapor reaction and aqueous chemical precipitation is studied. The superfine spherical Bi2O3 powder with an average diameter of 1 μm is made by plasma process. During the precipitation process, the micrograph of the Bi2O3 powder can be controlled through the reaction temperature, the rate of addition of the precipitation reagent, the reaction time and the amount of the dispersant. Accordingly, spherical Bi2O3 powder with diameters ranging from 2μm to 3μm is prepared. The spherical Bi2O3 particles have such advantages as uniform size distribution and excellent dispersing property. ZnO varistors made from the resultant powder exhibit properties of a low discharge voltage ratio, great eligibility coefficient measured by a rectangle wave of 2 ins 800 A and good stability in the above characteristics. 展开更多
关键词 spherical Bi2O3 plasma process precipitation process varistor
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Photodegradation of nitroaromatic compounds in aqueous solutions in the UV/H_2O_2 process 认领 引用 被引量：1
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作者 GOH Ngoh Khang 《Journal of Environmental Sciences》 SCIE EI CAS 2005年第6期886-893,共8页
Photodegradation of nitrobenzene and nitrophenols in aqueous solutions by means of UV/H2 O2 process was studied in the Rayox batch reactors. Three nitrophenol isomers were identified as main photoproducts in the irrad... Photodegradation of nitrobenzene and nitrophenols in aqueous solutions by means of UV/H2 O2 process was studied in the Rayox batch reactors. Three nitrophenol isomers were identified as main photoproducts in the irradiated NB aqueous solutions. The distribution of nitrophenol isomers follows the order p-〉 m-〉 o-nitrophenol. Other intermediates detected include nitrohydroquinone, nitrocatechol, catechol, benzoquinone, phenol, nitrateitrite ions, formic acid, glyoxylic acid, maleic acid, oxalic acid and some aliphatic ketones and aldehydes. The degradation of nitrobenzene and nitrophenols at initial stages follows the first-order kinetics and the decay rate constants for nitrobenzene（NB） are around l0^-3-10^-2 s^-1 and for nitrophenols are around 10^-2 s^-1. The decomposition of H2 O2 in the presence of NB and each nitrophenol isomers follows zero-order kinetics. The quantum yields at initial stages for NB decay were estimated around 0.30 to 0.36, and for NPs decay is around 0.31-0.54. 展开更多
关键词 photodegradation nitrobenzene nitrophenols UV/H2 O2 process
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Ti/Al_2O_3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process 认领 引用 被引量：2
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作者 Yimin LIZiqiao ZHENG 《Journal of Materials Science & Technology》 SCIE EI CAS 1999年第3期271-275,共5页
Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted expl... Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one 展开更多
关键词 Al SHS Ti/Al2O3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process
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Application of the Solvothermal Process in the Synthesis of High-performance Ag/γ-Al_2O_3 Catalysts 认领 引用
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作者 唐清 李锐星 +3 位作者 殷澍 Shingo Goto Daisuke Nagai Tsugio Sato 《过程工程学报》 EI CAS 北大核心 2006年第4期633-638,共6页
Ag/γ-Al2O3 is a kind of promising catalyst with the relatively lower cost compared with those using noble metals,good resistance against catalytic poisoning and excellent behaviour for NOx removal.In the present stud... Ag/γ-Al2O3 is a kind of promising catalyst with the relatively lower cost compared with those using noble metals,good resistance against catalytic poisoning and excellent behaviour for NOx removal.In the present study,Ag/γ-Al2O3 catalysts were synthesized by the solvothermal process and characterized by XRD,TG?DTA,TEM,UV?Vis and FT?IR.It was found that high-performance Ag/γ-Al2O3 catalysts could be synthesized by properly selecting starting materials,controlling the composition of solvent and other reaction conditions.The microstructure evolution of the catalysts was also discussed. 展开更多
关键词 Ag/γ-Al2O3 solvothermal process catalyst microstructure
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UV-vis辐照下H_2Fe_2Ti_3O10/TiO_2插层材料光催化活性的研究(英文) 认领 引用
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作者 黄昀昉 吴季怀 +3 位作者 李涛海 林建明 黄妙良 魏月琳 《人工晶体学报》 EI CAS 北大核心 2007年第5期978-984,共7页
在高压汞灯辐照下,通过插入反应将H2Fe2Ti3O10与n-C3H7NH2/C2H5OH和TiO2溶胶制备出H2Fe2Ti3O10/TiO2插层复合物。插入TiO2的层状钙钛矿化合物H2Fe2Ti3O10在UV-vis辐照下表现出高活性。实验结果表明H2Fe2Ti3O10/TiO2作为光催化剂在可见光... 在高压汞灯辐照下,通过插入反应将H2Fe2Ti3O10与n-C3H7NH2/C2H5OH和TiO2溶胶制备出H2Fe2Ti3O10/TiO2插层复合物。插入TiO2的层状钙钛矿化合物H2Fe2Ti3O10在UV-vis辐照下表现出高活性。实验结果表明H2Fe2Ti3O10/TiO2作为光催化剂在可见光(λ>420nm)下辐照24h,降解甲基橙的速率为59.0%。与相同条件下降解率只有24%的商用光催化剂TiO2(Degussa P-25)相比,H2Fe2Ti3O10/TiO2表现出了更高的光催化活性。 展开更多
关键词 光催化活性 插层材料 H2Fe2Ti3O10 TiO2
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Transition of Y_2BaCuO_5 Phase in Powder Melting Processed YBa_2Cu_3O7-xSuperconductors 认领 引用
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作者 FENG Jianqing LU Yafeng +6 位作者 XU Xiaoyan XIONG Xiaomei LIU Guoqing ZHANG Cuiping CHEN Shaokai ZHANG Pingxiang ZHOU Lian 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第4期620-623,共4页
The morphology and the formation of Y2BaCuO5 phase in powder melting processed YBa2Cu3O7-x superconductors were investigated.The experimental results show the heat treatment can not change the shape of Y2BaCuO5 partic... The morphology and the formation of Y2BaCuO5 phase in powder melting processed YBa2Cu3O7-x superconductors were investigated.The experimental results show the heat treatment can not change the shape of Y2BaCuO5 particles in powder melting processed samples.The formation of round Y2BaCuO5 phase is due to relative content of each constitution of precursor powders in powder melting process.For powder melting process,the excessive liquid phase is eliminated,which restrains the preferred growth of Y2BaCuO5 particles. 展开更多
关键词 morphology powder melting process YBa2Cu3O7-x scanning electron microscopy
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IN-SITU HVEM STUDY ON PHASE TRANSITION OF YBa_2Cu_3O7-x SUPERCONDUCTING COMPOUND IN PROCESS OF HEATING 认领 引用
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作者 王瑞坤 邸秀萱 +4 位作者 王振海 贺庆 俞定安 周和平 王英 《Journal of Rare Earths》 SCIE EI CAS 1990年第2期99-103,共5页
In-situ HVEM observation on phase transition of the YBa_2Cu_3O7-x superconducting compound in pro- cess of heating was carried out,and high temperature X-ray diffraction analysis in air and X-ray diffraction phase ... In-situ HVEM observation on phase transition of the YBa_2Cu_3O7-x superconducting compound in pro- cess of heating was carried out,and high temperature X-ray diffraction analysis in air and X-ray diffraction phase analysis for the sample treated in vacuum condition were made.The results showed that the temperature of phase transition is related to oxygen content in the sample and in general,is 100℃ to 120℃ lower in vacu- um condition than in air.At 320℃ to 350℃ twin bands begin to disappear,and some Cu_2O are formed on the surface of the sample and transit from orthorhombic YBa_2Cu_3O7-x to arthorhombic Y_2BaCuO_5 compound. This transition was completed at about 500℃.Above 900℃,this compound consists of the Y_2BaCuO_5, BaCuO_2,Y_2O_3 and some other minor compounds.No phase transition was observed during cooling the sample. 展开更多
关键词 HVEM SUPERCONDUCTING COMPOUND IN PROCESS OF HEATING IN-SITU HVEM STUDY ON PHASE TRANSITION OF YBa2Cu3O Cu
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STUDY OF PREPARATION AND PROPERTY OF YBa_2Cu_3O7-δ-Ag_x COMPOSITE SUPERCONDUCTORS PREPARED BY SOL-GEL PROCESS 认领 引用
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作者 袁启华 唐福龙 +1 位作者 佟钰 袁润章 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1996年第1期47-51,共5页
YBa2Cu3O7-δ-Agx composite superconductors were prepared by hybrid sintering process using YBa2Cu3O7-δ-Agx ultrafine powder and Ag2O finepower, which were prepared by sol-gel process and precipitation process respect... YBa2Cu3O7-δ-Agx composite superconductors were prepared by hybrid sintering process using YBa2Cu3O7-δ-Agx ultrafine powder and Ag2O finepower, which were prepared by sol-gel process and precipitation process respectively. The effect of the Ag content on superconducting crictical transition temperature of YBa2Cu3O7-δ-Agx was not evident as long as YBa2Cu3O7-δ-Agx can form continuous network. But Ag can increase superconduction crictical current and density of the composite superconductors. The normal state (i.e. non-superconducting state at room temperature) resistivity shows a percolation threshold at 20%-30% Ag, whereas the superconducting net-work shows a percolationthreshold at 70% -80% Ag. 展开更多
关键词 YBa2Cu3O7-δ-Agx superconductors sol-gel process.
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Advanced treatment of oil recovery wastewater from polymer flooding by UV/H_2O_2/O_3 and fine filtration 认领 引用 被引量：10
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作者 REN Guang-meng SUN De-zhi Jong Shik CHUNK 《Journal of Environmental Sciences》 SCIE EI CAS 2006年第1期29-32,共4页
In order to purify oil recovery wastewater from polymer flooding （ORWPF） in tertiary oil recovery in oil fields, advanced treatment of UV/H2O2/O3 and fine filtration were investigated. The experimental results showe... In order to purify oil recovery wastewater from polymer flooding （ORWPF） in tertiary oil recovery in oil fields, advanced treatment of UV/H2O2/O3 and fine filtration were investigated. The experimental results showed that polyacrylamide and oil remaining in ORWPF after the conventional treatment process could be effectively removed by UV/H2O2/O3 process. Fine filtration gave a high performance in eliminating suspended solids. The treated ORWPF can meet the quality requirement of the wastewater-bearing polymer injection in oilfield and be safely re-injected into oil reservoirs for oil recovery. 展开更多
关键词 oil recovery wastewater from polymer flooding UV/H2O2/O3 process polyacrylamide
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Structures and magnetic properties of nanocomposite CoFe_2O_4-BaTiO_3 fibers by organic gel-thermal decomposition process 认领 引用 被引量：3
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作者 周智 沈湘黔 +1 位作者 宋福展 闵春英 《Journal of Central South University》 SCIE EI CAS 2010年第6期1172-1176,共5页
The nanocomposite xCoFe2O4-(1-x)BaTiO3(x=0.2,0.3,0.4,0.5,molar fraction) fibers with fine diameters and high aspect ratios(length to diameter ratios) were prepared by the organic gel-thermal decomposition process from... The nanocomposite xCoFe2O4-(1-x)BaTiO3(x=0.2,0.3,0.4,0.5,molar fraction) fibers with fine diameters and high aspect ratios(length to diameter ratios) were prepared by the organic gel-thermal decomposition process from citric acid and metal salts.The structures and morphologies of gel precursors and fibers derived from thermal decomposition of the gel precursors were characterized by Fourier transform infrared spectroscopy,X-ray diffractometry and scanning electron microscopy.The magnetic properties of the nanocomposite fibers were measured by vibrating sample magnetometer.The nanocomposite fibers consisting of ferrite(CoFe2O4) and perovskite(BaTiO3) are formed at the calcination temperature of 900 ℃ for 2 h.The average grain sizes of CoFe2O4 and BaTiO3 in the nanocomposite fibers increase from 25 to 65 nm with the calcination temperature from 900 to 1 180 ℃.The single fiber constructed from these nanograins of CoFe2O4 and BaTiO3 has a necklace-like morphology.The saturation magnetization of the nanocomposite 0.4CoFe2O4-0.6BaTiO3 fibers increases with the increase of CoFe2O4 grain size,while the coercivity reaches a maximum value when the average grain size of CoFe2O4 is around the critical single-domain size of 45 nm obtained at 1 000 ℃.The saturation magnetization and remanence of the nanocomposite xCoFe2O4-(1-x)BaTiO3(x=0.2,0.3,0.4,0.5) fibers almost exhibit a linear relationship with the molar fraction of CoFe2O4 in the nanocomposites. 展开更多
关键词 nanocomposite CeFe2O4 BaTiO3 fiber organic gel-thermal decomposition process magnetic property
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Photolysis pathway of nitroaromatic compounds in aqueous solutions in the UV/H_2O_2 process 认领 引用 被引量：2
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作者 GOH Ngoh Khang 《Journal of Environmental Sciences》 SCIE EI CAS 2006年第6期1061-1064,共4页
Nitroaromatic compounds such as nitrobenzene and nitrophenols are largely synthesised and particularly often occur in water bodies as toxic pollutants. The degradation of these compounds in the environment via direct ... Nitroaromatic compounds such as nitrobenzene and nitrophenols are largely synthesised and particularly often occur in water bodies as toxic pollutants. The degradation of these compounds in the environment via direct photolysis and by biological treatment is difficult and usually slow. In our two previous published papers, we have discussed the advanced oxidation of nitrobenzene and nitrophenols in aqueous solutions irradiated by direct photolysis using polychromatic light and by means of UV/H2O2 process. The experimental results suggested the UV/H2O2 process is an effective and efficient technology for complete mineralization of these organic compounds. Based on the results therein, comprehensive reaction mechanism for nitrobenzene photolysis was proposed with detailed discussions. 展开更多
关键词 photolysis pathway nitrobenzene nitrophenols UV/H2O2 process
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