助剂对负载型金催化剂催化氧化甲醛的影响

采用等体积浸渍法制备了3种不同助剂的Au/Fe Ox/Al2O3、Au/Ce O2/Al2O3、Au/Ti O2/Al2O3纳米金复合催化剂,其中Au负载量为1%(质量分数).利用XRD、BET和透射电镜(TEM)技术对催化剂进行表征,并通过室温催化氧化甲醛进行活性评价.结果表明:在3种不同助剂的复合催化剂中,Au/Fe Ox/Al2O3、Au/Ce O2/Al2O3表现出较好的甲醛催化氧化活性.其中,1%Fe Ox为助剂的复合催化剂的甲醛完全转化率最高.     

Au/Al_2O_3/Al整体型催化剂的研究

采用阳极氧化法制备了Al2O3/Al载体,研究了阳极氧化条件(硫酸浓度、电流密度、氧化时间等)对载体比表面积和孔结构的影响.用这种载体,经过水合或负载CeO2、Fe2O3等助剂对载体的不同处理后,采用浸渍法制备了金负载量为1%的Au/Al2O3/Al、Au/Al2O3-CeO2/Al、Au/Al2O3-Fe2O3/Al催化剂,考察了其CO催化氧化活性.结果表明:阳极氧化条件对载体的表面结构有着显著的影响,同时也明显影响到催化剂的活性;助剂CeO2的加入能明显提高催化剂的活性.     

有氧条件下Au/CeO2/Al2O3催化还原NO的研究

NO是形成光化学烟雾、生成酸雨和破坏大气臭氧层的前驱气体之一,消除NO已成为近几年国内外催化界的研究热点.Cu-ZSM-5是国内外研究最成熟的催化剂,但实用性差.本研究以HAuCl4为前驱体,沉积-沉淀法制备Au/CeO2/Al2O3催化剂,用X-射线衍射(XRD )进行表征,考察了加入CeO2对Au/CeO2/Al2O3催化活性的影响.结果表明Al2O3、CeO2/A l2O3表面的Au晶粒小, 分散度高.Au/Al2O3的deNOx活性较低,而含金复合催化剂Au/CeO2/Al2O3的活性高于Au/Al2O3及Cu-ZSM-5.     

有氧条件下Au/CeO2/Al2O3催化还原NO的研究

NO是形成光化学烟雾、生成酸雨和破坏大气臭氧层的前驱气体之一，消除NO巳成为近几年国内外催化界的研究热点，Cu0-ZSM-5是国内外研究最成熟的催化剂，但实用性差，本研究以HAuCl4为前驱体，沉积-沉淀法制备Au/CeO2/Al2O3催化剂，用X-射线衍射（XRD）进行表征，考察了加入CeO2对Au/CeO2/Al2O3催化活性的影响。结果表明：Al2O3、CeO2/Al2O3表面的Au晶粒小，分散度高，Au/Al2O3的deNOx活性较低，而含金复合催化剂Au/CeO2/Al2O3的活性高于Au/Al2O3及Cu-ZSM-5。     

碳纳米管促进Au/Al2O3对甲酸分解的催化研究

利用碳纳米管(CNTs)作为添加剂,研发出一种高效新型的Au/CNTs-Al2O3催化剂,其对甲酸分解脱氢具有较高催化活性.经过优化后的Au/CNTs-Al2O3催化剂,在甲酸和甲酸钠摩尔比为7∶3的条件下,363K时甲酸分解的转化频率可达356h-1,比没有掺杂CNTs的Au/Al2O3基底催化剂的活性提高了71%,比直接使用CNTs作载体的Au/CNTs催化剂提高了236%.利用气相色谱检测分解后的气体产物,发现其中CO的体积分数小于0.01%,保证了分解得到的氢气的清洁与干净.联合谱学表征结果表明,CNTs的加入不仅增大了载体的比表面积,而且高度分散了催化剂表面Au粒子使其粒径保持在2nm左右,另外还提高了催化剂表面活性物种Au0的比例.同时,CNTs的高吸氢、储氢能力,也有助于活性位上甲酸分子解离下来的氢物种向CNTs溢流、扩散,从而促进了甲酸脱氢的活性.     

载体对Au催化剂乙醇部分氧化制氢性能的影响

采用共沉淀制备方法分别制备Au/Al2O3、Au/ZnO、Au/CeO2、Au/Fe2O3催化剂,考察不同载体对乙醇部分氧化制氢性能的影响,并用XRD、H2-TPR、H2-TPD等对各催化剂的晶相结构、表面还原性、吸附性能等进行表征,考察载体对Au催化剂的活性和选择性的影响.结果表明,载体对Au催化剂的催化性能与H2的...     

负载型金催化剂的制备及其对CO催化氧化性能的研究

通过沉积沉淀法制备了负载型金催化剂,测定了其对CO的催化氧化性能.结果表明,催化剂的活性与催化剂的载体种类、焙烧温度和放置时间等因素有关;Au/TiO2和Au/CeO2催化剂的催化活性较高,而Au/ZnO催化剂的催化活性较低;焙烧温度影响催化剂的性能,焙烧温度为400℃时,催化剂活性最高;较长的放置时间会降低催化剂性能,这可能与活性组分粒径长大有关.     

Au/γ-Al2O3催化剂上高浓度甲醇催化消除反应的研究

采用沉积沉淀法制备了负载型Au/γ-Al2O3催化剂,并进行了BET、SEM等表征.对高浓度甲醇蒸汽进行催化消除反应.探讨了载体粒径、金含量和活化气体(O2、N2、H2)对催化剂性能的影响.结果表明:载体粒径不同的催化剂表面积不同,不同的活化气体对反应产物有很大影响.在O2活化的最佳催化剂Au(2.0%)/γ-Al2O3(0.4-0.5 mm)上浓度为86.3 g/m3的甲醇的最低全转化温度是170℃,产物中CO2和甲醚的选择性分别为99.7%和0.3%,达到国家安全排放标准.图1,表3,参16.     

催化剂Au/Ce0.6Zr0.35Y0.05O2对一氧化碳氧化的催化活性研究

通过研究催化剂Au/Ce0.6Zr0.35Y0.05O2(Au/CZY)的活化能,以及对煅烧温度和催化剂活性的关系研究,揭示了负载金催化剂Au/CZY比纯CZY及Au/CeO2具有更高的一氧化碳氧化活性的原因是Au/CZY催化剂具有较低的活化能和较大的比表面积。     

Ag/Al2O3选择性还原整体式催化剂的制备

为使Ag/ Al2O3催化剂在处理稀燃机动车尾气中NOX实用化,以堇青石蜂窝陶瓷为载体,以活性 Al2O3为涂层,以Ag作为活性组分,制备了Ag/ Al2O3整体式催化剂,考察了整体式Ag/ Al2O3催化剂制备过程中氧化铝涂层的形成以及Ag活性组分负载过程中干燥方式和焙烧气氛条件对催化剂还原反应活性的影响.实验结果表明,通过微波干燥方式明显提高了Ag在 Al2O3表面的分散性,有助于提高催化剂的NOX还原反应活性;焙烧气氛对催化剂的活性没有明显影响.氧化铝涂层负载量的增加有利于增加单位体积载体上的Ag活性位数量,从而使反应温度窗口得到扩展, NOX转化率得到提高.     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

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     

Call for Papers

<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