钼酸镧超细微粒催化剂的合成及表征

以柠檬酸为络合剂,采用溶胶-凝胶法合成了La2(MoO4)3超细微粒催化剂,使用DTA-TG、IR、XRD以及BET比表面测试等表征手段,考察了制备条件与热处理条件对复合氧化物超细微粒形成、结构和表面积的影响。结果表明：本文法制备的La2(MoO4)3复合氧化物的比表面积远远大于共沉淀法制得的类似样品的比表面积,在氮气气氛中分解La2(MoO4)3凝胶中的柠檬酸,可有效地避免柠檬酸分解发生氧化燃烧而引起微粒烧结。     

烟气直接还原脱硫催化剂研究

实验考察了Cr2O3、MoO3、WO3三种单组分氧化物催化剂，以及四种不同催化载体对SO2直接催化还原的影响，结果表明它们的活性相差很大，WO3的活性最差，MoO3的活性最高；具有酸碱双功能的γ-Al2O3载体是催化脱硫的最佳载体．此外，制备了三种双组分金属氧化物负载催化剂，其催化脱硫活性顺序是：Mo—Co／γ-Al2O3＞Mo—Fe／γ-Al2O3＞Mo—No／γ-Al2O3；Mo—Co双组分催化比单组分MoO3具有优越性，在250—400℃范围内，SO2脱除率达90％以上，不仅催化脱硫活性比较高，而且催化剂不易失活．     

CeO2在Al2O3及TiO2载体上的分散

采用等体积浸渍法制备了CeO2/Al2O3、CeO2/TiO2复合氧化物载体。应用X-射线粉末衍射（XRD）、比表面积测定、激光Raman光谱、扫描电子显微镜（SEM）等技术研究了CeO2在Al2O3及TiO2载体上的分散状态。结果显示：对CeO2/Al2O3，CeO2主要存在于Al2O3表面，晶粒小、分散性好；而对CeO2/TiO2，大部分CeO2以体相形式与TiO2共存，晶粒大、分散性也差。此外，也没有发现TiO2由锐钛矿向金红石的晶相变化。CeO2/Al2O3具有比Ce/TiO2更大的比表面积，更适合用于催化剂的载体。     

Fe2O3-MoO3-Sb2O3体系中的固相反应

通过混合焙烧的方法制备Fe2O3MoO3Sb2O3复合氧化物.采用X射线衍射(XRD)、同步热重差示扫描量热(TGDSC)和穆斯堡尔(Mssbauer)谱研究Fe2O3MoO3Sb2O3三组分体系在不同温度下的固相反应,并分别与Fe2O3MoO3和Fe2O3Sb2O3双组分体系的结果加以对比.结果表明,Sb2O3加入到Fe2O3MoO3体系中抑制了Fe2(MoO4)3的形成,而MoO3加入到Fe2O3Sb2O3体系,则可显著促进FeSbO4的生成.     

La-Cu-Mn系钙钛矿型复合氧化物的表面特征

采用以EDTA为配位剂的Sol-gel法制备La-Mn体系钙钛矿型复合氧化物，借助X射线衍射（XRD），X射线光电子能谱（XPS）等手段对其表面的结构和性质进行表征。结果表明，Cu^2 部分取代A位、B位或同时部分取代A位、B位将导致氧化物特征发生变化，部分取代A位的La^3 比部分取代B位的Mn^3 更有利于锰离子在表面富集，更能提高晶格氧的相对含量和阳离子缺陷的浓度，但对Mn^3 含量的影响程度没有明显差异。     

过渡金属氧化物表界面催化氧化的理论研究进展

过渡金属氧化物,如V、Mo和Fe基氧化物及其复合氧化物已被广泛地应用于催化氧化反应.本文主要回顾本课题组在氧化物表界面理论催化机理研究的进展,重点讨论了3个方面的问题:1)高价金属氧化物对烷烃C—H键的氧化活化机理;2)多组分氧化物在C—H键氧化中的作用;3)界面(氢)氧化物的结构及其对CO氧化的影响.对比近期相关的理论和实验研究结果,可以获得丰富的机理信息.     

载体SiO2表面修饰对钒基催化剂丙烷氧化脱氢催化性能的影响

用ＸＲＤ,Ｒａｍａｎ,ＦＴ－ＩＲ,＾５１Ｖ－ＮＭＲ,Ｐｙ－ＩＲ和ＴＰＲ－ＴＰＯ表征ＳｉＯ２或ＳｉＯ２上预负载ＭｇＯ后负载的钒氧化物催化剂体系。ＳｉＯ２上直接负载钒氧化物,在钒负载量约为５ｗｔ％Ｖ２Ｏ５时出现Ｖ２Ｏ５晶相,而预负载ＭｇＯ在相同钒含量时则没有出现Ｖ２Ｏ５晶相,表面预负载ＭｇＯ促进了钒氧化物在载体表面的分散。     

丙烯醛氧化催化剂及在6万吨／年工业装置上的应用

制备了Mo-V体系复合氧化物,考察了其丙烯醛氧化性能和在6．0×10^5t／a工业装置上的应用情况．结果表明,催化剂为由MoO3,M5O14和（Sb2O）MeO18（M—Mo,W,V）晶相组成的粒径在1～5μm的复合氧化物,对丙烯醛氧化反应具有优良的催化性能,在6．0×10^5t／a工业生产装置上的反应性能与进口催化剂相当．     

几种过渡金属氧化物在肉桂醛MPV还原中的作用

以几种负载在γ-Al2O3表面的过渡金属氧化物(La2O3、ZrO2、NiO、ZnO、CuO和CoOx)作为肉桂醛液相MPV反应的催化剂.实验结果表明,在相同的实验条件下,这些氧化物组分均对肉桂醛的MPV反应显示出不同的催化活性;在异丙醇和甲苯中这些氧化物对肉桂醛的MPV反应显示不同的活性;而La2O3的催化活性最高.     

炭负载Co-Mo催化剂的二苯并噻吩加氢脱硫性能研究

利用X射线衍射及程序升温还原技术，对等体积浸渍法制备的Co-Mo/AC催化剂进行了表征。采用高压微反装置、以二苯并噻吩为模型化合物，在一定的温度和空速下对催化剂进行了加氢脱硫活性评价。X射线衍射表征结果表明，柱状活性炭具有良好的担载催化剂活性组分的能力，活性组分在载体表面能很好地分散，因而只检测到部分活性组分很弱的衍射峰。在120℃和260℃条件下处理的催化剂表面物种主要是MoO3，没有发现含Co的物种和CoMoO复合氧化物的衍射峰；500℃焙烧处理的催化剂的表面物种主要是MoO2。程序升温还原表征结果表明，Co-Mo／AC催化剂表面物种的还原温度低于Co-Mo/γ-Al2O3催化剂。加氢脱硫活性评价结果表明，催化剂的还原特性和加氢脱硫活性有一定的对应关系。在Co-Mo/AC体系中，Co与Mo原子比为0．7的催化剂的加氢脱硫活性高于γ-Al2O3负载的Co-Mo催化剂；而Co与Mo原子比为0.2，0．35和0．5的Co-Mo／AC催化剂的加氢脱硫活性却低于Co-Mo/γ-Al2O3催化剂。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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