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1.
在自制的流化床光催化反应装置中进行了TiO2光催化剂的载体选择与催化动力学研究,考察了石英砂、陶瓷球、粗孔硅胶和活性炭颗粒四种栽体的负载型TiO2催化剂光催化降解甲苯的性能及TiO2/粗孔硅胶的催化反应动力学。结果表明,粗孔硅胶是最适用于气固流化床光催化反应体系的载体;TiO2/粗孔硅胶光催化氧化甲苯反应符合Langmuir—Hinshelwood动力学模型,反应速率常数k为2.06262mg/(m^3·min),吸附平衡常数K为0.03683m^3/mg。  相似文献   

2.
半导体光催化氧化反应降解废水中有机污染物的研究进展   总被引:2,自引:3,他引:2  
介绍了一种降解废水中有机污染物的高效氧化方法(AOP)-半导体光催化氧化法及其作用原理与反应机理;总结了近年来提高半导体光催化效率的方法:半导体光催化剂的改性、光催化剂的固定化、加电子接受剂或空穴接受剂,特别是采用AOP与生化降解法相结合的方法,使废水的处理更经济、有效。综述了近两年该技术在处理废水中有机污染物方面的应用。  相似文献   

3.
光催化技术在降解无机含氮污染物方面的应用   总被引:2,自引:0,他引:2  
光催化技术是一种新兴的高效节能绿色环保技术,本文在介绍半导体光催化反应机理的基础上、对NOx、NO2^-污染物光催化降解的现状、提高半导体光催化剂活性的途径、光催化技术发展中存在问题等进行了综述,重点介绍了半导体光催化技术在降解无机含氮污染物方面的应用。  相似文献   

4.
该文介绍了光催化氧化技术的原理,从传统光催化剂的改性、新型光催化剂开发等角度阐述了光催化降解水中污染物的研究进展,分析了提高光催化反应效果的途径和今后光催化氧化剂的研发方向.  相似文献   

5.
光催化氧化能降解直至矿化多种有机污染物,是一种极具应用前景的水处理技术.对光催化氧化在国内外的研究和应用现状进行了介绍,包括均相和非均相光催化氧化机理、影响因素、实际应用、反应动力学、反应器、催化剂等,并讨论光催化氧化目前存在的问题及今后研究的发展方向.  相似文献   

6.
光催化TiO2薄膜研究进展及其影响因素   总被引:2,自引:0,他引:2  
提高光催化剂的光催化活性是多相光催化剂能否工业化应用的关键,文章介绍了半导体多相光催化材料的理论及应用的发展现状,探讨了玻璃表面TiO2薄膜光催化性能的影响因素及提高其光催化降解效率的途径。  相似文献   

7.
掺铜方法对二氧化钛光催化氧化还原性能的影响   总被引:3,自引:0,他引:3  
采用浸渍法、水解沉淀法、机械混合法制备了铜掺杂的TiO2光催化剂.利用XRD,XPS,TPR等手段对不同样品进行了表征,以乙酸水溶液的光催化氧化降解及二氧化碳光催化还原为反应探针,对3种催化剂光催化活性进行了评价.结果表明,不同方法掺铜影响催化剂表面性质如吸附氧、元素价态及分布,进而影响光催化性能.吸附氧的性能以及存在合适比例的氧化还原对Cu+/Cu2+导致浸渍法制备的掺铜TiO2光催化剂具有最好的光催化活性.  相似文献   

8.
研究了纳米TiO2对甘氨酸的光催化氧化性能及其氧化机理.结果表明,在实验浓度范围内,甘氨酸的光催化氧化符合准一级动力学反应.纳米TiO2的用量和溶液pH值都影响光催化反应.外加无机氧化物,能有效地捕获光致电子,增加溶液中羟基自由基的浓度,提高甘氨酸的光催化氧化能力.  相似文献   

9.
流化光催化反应器降解水中有机污染物   总被引:3,自引:0,他引:3  
采用溶胶一凝胶结合CO2超临界干燥方法与浸渍法制得了颗粒型与薄膜型TiO2光催化剂,选择苯酚和苯胺为炼厂废水难降解污染物的模型物,通过流化光催化反应器与固定式光催化反应器考察了反应条件对苯酚、苯胺降解的影响.实验结果表明,溶胶—凝胶结合CO2超临界干燥方法有利于制很大比表面、大孔容、高活性TiO2催化剂,流化光催化反应器对苯酚、苯胺的降解效果要优于浆式反应器与固定式反应器,光催化方法适宜于对低浓度污染物废水的深度处理,优化反应条件有利于提高光催化效率.  相似文献   

10.
光催化技术是一种新兴的高效节能现代污水处理技术,从半导体光催化方法、反应机理、各类污染物光催化降解的现状、提高半导体光催化剂活性的途径、光催化技术发展中存在问题等方面分别论述了半导体光催化技术现状及发展趋势.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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