高温催化燃烧技术及其核催化剂的研制

高温催化燃烧技术作为一项环境友好的能源利用方式下得到世界各国的广泛重视,催化燃烧器设计与燃烧催华化剂研制领域不断取得新进展。本文通过考察负载型Pd催化剂和烧绿石型复氧化物催化剂的物化学特性与催化反应动力学特征,探讨了改良现有催化剂体系反应性能的有效途径。     

煤催化气化的修正缩核反应模型研究

针对煤的催化气化反应中以往的动力学模型不再适用这一情况，以气固非催化缩核反应动力学模型为基础，考虑了催化剂对反应的作用，并将催化剂的影响因素用一个催化有效因子函数来表达，该函数包括催化剂的催化能力、加入量以及滞留效应等；建立了适合于煤催化气化反应的修正缩核反应动力学模型．结果表明，在模型适用范围内模型模拟值与实验结果吻合良好，误差在l.4％以内．     

氯化钾催化气化煤的等温动力学研究

采用KCl作为催化剂，CO2作为气化剂，对3种不同的煤进行了等温常压催化气化动力学研究，发现KCl对这几种煤的气化有着明显的催化作用。根据反应动力学结果，认为此催化气化反应过程本身为一级反应，但受到催化剂的影响，在反应后期会表现为按二级反应进行。针对该情况引入一个描述催化剂影响因素的参数——催化因子建立了动力学模型，模型值与实验值吻合良好，最大误差不超过5．4%。     

煤焦催化气化的修正随机孔模型研究

针对煤焦催化气化中传统的动力学模型不再适用这一情况，以广泛应用于煤焦气化动力学研究的随机孔模型为基础，考虑了催化剂对反应过程的催化作用，通过引入催化作用因子，建立了适用于煤焦催化气化反应的修正随机孔模型．选取神府煤焦为研究对象，将煤焦CO2催化气化作为探针反应，做了典型KCl催化荆和K-Ni复合催化剂的催化气化实验，并对模型进行了验证．结果表明：修正随机孔模型较好地体现了煤焦催化气化的动力学规律，即催化剂的添加有效地增大了反应界面处的活性部位和活性表面积，使气化反应在更温和的条件下快速进行．经验常数说明Ni-K复合催化剂的催化能力大于KCl催化剂，这与许多学者的研究结果是一致的．另外，由于反应初期的传质阻力不可忽略，故实验值与模拟值存在一定误差．     

铜锰负载型堇青石整体催化剂表面低浓度甲烷催化燃烧本征动力学研究

采用等温积分反应器，在常压、600~700℃和甲烷体积分数0.1%~1%的条件下，对国产铜锰负载型堇青石整体催化剂上低浓度甲烷催化燃烧本征动力学特性进行了系统的实验研究。以单纯形法对动力学实验数据进行最优化参数估计，建立了低浓度甲烷催化燃烧双曲型本征动力学模型，数理统计和残差分布检验结果表明，所建模型与实验结果良好相容，是适宜和可信的。     

水泥窑用煤燃烧动力学研究

采用热重分析法对南宁无烟煤在加入催化剂ZnO、NaClO4、Na2Cr2O7、Fe2O3和MnO2前后的燃烧动力学特性进行研究。结果表明,添加的5种催化剂都具有催化效果,但对煤燃烧动力学特性影响程度有所不同;催化剂Na2Cr2O7能改变燃烧反应机理,提高煤的燃烧速率,更有利于煤的完全燃烧;催化剂能够不同程度地降低煤燃烧的表观活化能,使煤的着火点降低;5种催化剂的催化效果依次为:Na2Cr2O7>NaClO4>ZnO>Fe2O3>MnO2。     

甲烷催化燃烧催化剂的研究进展

甲烷催化燃烧的目的是通过催化作用降低其起燃温度(T_(10))和完全转化温度(T_(90)),加深其氧化程度,从而提高燃料的利用率。简述了甲烷催化燃烧反应的机理,从种类、制备方法以及催化性能等方面详细介绍了甲烷催化燃烧催化剂的最新进展。贵金属催化剂的催化性能优越,但高成本以及热稳定性差等因素极大地限制了其应用;非贵金属催化剂尤其是复合金属氧化物催化剂(例如钙钛矿型复合金属氧化物催化剂和六铝酸盐系列催化剂等)拥有较高的催化活性,因其成本低,有更好的发展前景。提高非贵金属催化剂的低温催化活性和高温热稳定性是今后甲烷催化燃烧催化剂的主要研究方向。     

发动机催化燃烧多维数值模拟

将发动机三维CFD程序KIVA-3V与化学动力学程序CHEMKIN Ⅲ及DETCHEM相耦合,模拟了催化燃烧对均质压燃(HCCI)发动机燃烧过程及排放的影响.发动机以甲烷为燃料,其表面和空间氧化反应采用了详细的动力学机理.利用此模型分析了活塞顶催化剂铂(Pt)或铑(Rh)涂层对HCCI发动机着火时刻、缸内温度场及HC、CO、NOx 排放的影响,结果表明催化燃烧会使HCCI发动机着火时刻提前,同时能降低HC、CO的排放,但会提高NOx 的排放;在相同工况下,相比催化剂Pt,催化剂Rh使HCCI发动机着火时刻提前的幅度要大,同时HC的排放要低,但CO及NOx 的排放要高.     

甘氨酸燃烧法制备Co/CeO_2催化剂用于CO选择性氧化脱除

采用甘氨酸燃烧法制备了不同负载量的Co/CeO_2催化剂,考察了钴负载量和反应温度对其在富氢气氛中选择性催化氧化CO的反应性能,并与浸渍法制备的Co/CeO_2催化剂进行了对比;同时采用XRD、SEM和H_2-TPR等手段对催化剂进行了表征.结果表明,在富氢气氛下,甘氨酸燃烧法制备的Co/CeO_2催化剂,对CO的选择性催化氧化反应,具有较好的低温反应活性和较高的选择性.当钴金属氧化物负载量为30%时,在150~200℃,催化剂对CO的催化氧化率达到99%以上;并且在反应温度为150℃时,催化剂对CO催化氧化的选择性达到100%.另外,通过用XRD、Raman和TPR对催化剂进行分析表征,在甘氨酸燃烧法制备的催化剂中Co_3O_4具有较好的分散度,Co和Ce之间的相互协同作用提高了催化剂的催化氧化活性和选择性.     

用钨杂多酸／膨润土催化剂催化合成丙酸乙酯

膨润土不经传统的交联反应，直接进行改性，经钨杂多酸处理制得催化剂，用连续流动法气－固相催化合成的丙酸乙酯，获得了很好的催化效果，用吡啶吸附红外、ＳＥＭ、ＩＣＰ、ＤＴＡ等手段表片了催化剂。同时对丙酸和乙醇反应动力学条件进行了探讨，得出获得高酯产率的适宜反应条件。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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