小角X射线散射-分割分布函数法的建立和应用

本文介绍了小角X射线散射-分割分布函数法(SAXS-DDF)的建立,并用该方法测定了γ-Al_2O_3超细粉末和La改性的Ni/α-Al_2O_3催化剂中载体表面上活性组分Ni的粘度分布。该方法把计算散射强度的积分方程转化为线性方程组,采用合理的数学模型和计算机程序相继给出平均粒度、比表面、粒度组成和直方图等特征参数。对测定方法的童复性和可靠性进行了验证。用透射电子显微镜的照片结果证实了Ni/α-Al_2O_3催化剂中活性组分颗粒所呈的形状和粒度分布的规律。测试结果说明,SAXS-DDF法适合于测试单相超细粉末或两相催化剂中金属活性组分颗粒的粒度分布。     

γ—Al2O3载体的宏观结构对加氢脱硫催化剂活性的影响

本文采用比表面积、孔径、孔容测定,TPR,DOC,XRD及HDS反应活性评价等实验方法,探讨了钴钼系HDS催化剂中五种不同来源的γ-Al_2O_3载体及其被TiO_2改性后,表面宏观结构对HDS反应活性的影响。发现在不同的γ-Al_2O_3为载体的HDS催化剂上噻吩HDS活性中心的性质一样;载体的孔分布、孔容对HDS反应活性有直接影响。孔半径为20～50的中孔分布>60％,孔容(P.V)为～0.4ml.g~(-1)的γ-Al_2O_3为较好的载体。同时,TiO_2改性后的γ-Al_2O_3载体,增强了活性组分与载体的相互作用,使MoO_3,不易被还原,对提高HDS反应活性不利。     

载体对纳米NiB催化肉桂酸加氢催化活性与稳定性的影响

采用浸渍-还原法制备负载型纳米NiB催化剂,以肉桂酸加氢反应为模型,考察载体(γ-Al_2O_3、SiO_2、TiO_2)对催化剂的催化活性和稳定性的影响.发现载体γ-Al_2O_3具有较好的分散镍活性组分的作用,在多次循环使用后催化剂活性组分流失较少.负载型NiB/γ-Al_2O_3催化剂在肉桂酸加氢反应中表现出较好的稳定性,此外,催化剂套用次数越多其活性反而越高,连续反应3次后肉桂酸的转化率可达75.0%,其加氢产物的选择性仍然保持在100%.通过系列表征,发现其最主要的原因可归为随着反应的不断进行载体孔道中的活性组分纳米NiB逐步暴露所致,更重要的是载体γ-Al_2O_3能够有效抑制活性组分的流失和团聚.     

介孔氧化铝催化甲醇氢氯化合成氯甲烷

氯甲烷是一种在世界范围内广泛应用的化学产品。本研究以蔗糖为模板剂、异丙醇铝为铝源制备固体酸γ-Al_2O_3催化剂,研究了该催化剂催化甲醇氢氯化合成一氯甲烷的性能。在催化剂制备过程中改变pH和物料比,活性测试结果表明:在相同的实验条件下,pH为5.5和蔗糖与异丙醇铝的摩尔比值为1∶1时,制备的介孔γ-Al_2O_3催化剂的甲醇转化率较商品γ-Al_2O_3催化剂的甲醇转化率有大幅提高。通过BET及吡啶红外的测试结果表明:以蔗糖为模板剂制备的催化剂具有较大的比表面,孔径分布集中,表面Lewis酸活性位点浓度较高。研究分析结果表明:固体酸γ-Al_2O_3催化剂的活性与催化剂表面的Lewis中强酸浓度有关,较高的中强酸浓度有助于提高催化剂活性。     

不同载体上硫化的钼催化剂甲烷化反应与低温氧吸附的研究

本文研究了不同载体γ-Al_2O_3、ZrO_2、CeO_2和La_2O_3上硫化的钼催化剂的甲烷化反应性能,得到甲烷化活性顺序:Mo/ZrO_2>Mo/γ-Al_2O_3>Mo/CoO_2>Mo/La_2O_3;热稳定性顺序:Mo/La_2O_3>Mo/CeO_2>Mo/γ-Al_2O_3>Mo/ZrO_2。研究了低温氧吸附的预处理条件,并用脉冲色谱法测定了载体,反应前和反应后催化剂的氧吸附量。结果表明反应后低温氧吸附量下降百分数和活性下降百分数有线性关系。讨论了以低温氧吸附与甲烷化活性进行关联的限制和活性中心的本质。     

Sn杂化氧化铝球的制备及其在丙烷脱氢中的应用

采用海藻酸铵辅助法制备了Sn杂化Al_2O_3球形颗粒,并通过浸渍法获得Pt/Snx-Al_2O_3-X催化剂.采用氮吸附-脱附、XRD、NH3-TPD、XPS与TEM,研究了Sn杂化量与煅烧温度对催化剂孔结构、晶相、表面酸性、Sn价态、催化剂表面Pt颗粒大小的影响,并评估了催化剂在丙烷脱氢过程中的反应活性.实验结果表明,Sn的引入没有改变γ-Al_2O_3的晶相,但是可以提高催化剂的热稳定性;随着煅烧温度的提高,催化剂孔容、孔径明显增加,而比表面积与表面总酸量明显减少;Pt/Sn15-Al_2O_3-800催化剂表面Pt、Sn与γ-Al_2O_3之间相互作用较强,Sn0含量较低,同时Pt粒子平均粒径最小,其丙烷脱氢活性也最好,收率可达35%,以上.     

金属基体整体式阳极Al_2O_3催化剂上二氯甲烷的催化燃烧

通过水热和焙烧处理将板状多孔阳极Al_2O_3材料制备成一种金属基体整体式催化剂材料,在无活性组分负载的情况下直接将其作为催化剂,考察其在二氯甲烷催化燃烧反应中的性能。通过与商业γ-Al_2O_3的对比研究,重点考察水热处理条件对催化剂活性和耐久性的影响。使用扫描电子显微镜(SEM)、N_2吸附-脱附、NH_3程序升温脱附(NH_3-TPD)、热分析(TG)和X线衍射仪(XRD)等对样品的结构和理化特性进行表征。结果表明:水热处理在增大样品比表面积的同时,增加了表面酸浓度和亲水性。与商业γ-Al_2O_3在二氯甲烷催化燃烧反应中的性能相比,水热处理的样品在低温下产生了更多的HCl,并显示出更加优异的耐久性。     

CeO_2改性NiO/γ-Al_2O_3催化剂的苯胺焦油加氢轻质化

采用分步沉淀法制备CeO_2改性NiO/γ-Al_2O_3催化剂,通过比表面积分析(BET)、X线衍射(XRD)、H2程序升温还原(H2-TPR)、H2程序升温脱附(H2-TPD)对催化剂结构和物化性能进行表征,研究催化剂对苯胺焦油加氢裂化的反应活性。结果表明:适量加入CeO_2可提高NiO在载体γ-Al_2O_3表面的分散,提高NiO/CeO_2/γ-Al_2O_3催化剂的还原性及吸氢能力,进而提高催化剂的活性和稳定性。采用CeO_2质量分数15%的NiO/CeO_2/γ-Al_2O_3催化剂,在反应温度265℃、反应压力3.0 MPa、液时空速0.3 h-1和氢油体积比2 000的条件下,苯胺焦油裂解率为100%,胺类物质收率为58.54%。     

γ-Al_2O_3球和蜂窝陶瓷负载Fe_2O_3臭氧氧化降解丙烯酸废水的研究

以γ-Al_2O_3颗粒和蜂窝陶瓷为载体,采用硝酸盐浸渍法制备了负载Fe_2O_3的两种催化剂,Fe_2O_3/γ-Al_2O_3催化剂和Fe_2O_3/蜂窝陶瓷催化剂.分别测试了蜂窝陶瓷、Fe_2O_3/蜂窝陶瓷催化剂和γ-Al_2O_3、Fe_2O_3/γ-Al_2O_3催化剂的比表面积;以丙烯酸废水中的丙烯酸作为目标污染物,分别对比了单独臭氧氧化、Fe_2O_3/γ-Al_2O_3催化剂和Fe_2O_3/蜂窝陶瓷催化对丙烯酸的降解效果.结果表明,Fe_2O_3/蜂窝陶瓷和Fe_2O_3/γ-Al_2O_3催化剂对丙烯酸的COD的去除率分别为93.4%和83.1%,比单独臭氧氧化时的COD去除率69.9%有大幅度的提高;Fe_2O_3/蜂窝陶瓷和Fe_2O_3/γ-Al_2O_3催化剂对丙烯酸的TOC的去除率分别为82.7%和75.2%,与单独臭氧氧化时TOC去除率相比,分别提高了31%和24%.     

CuO—La2O3／γ—Al2O3上CO和NO吸附的红外光谱研究

应用XRD分析了催化剂的体相结构,用红外光谱研究了CO和NO在CuO-La_2O_3/γ-Al_2O_3催化剂上的吸附,并对表面铜的价态进行了表征。氧化态样品的体相存在CuO、CuAl_2O_4,可能还有CuLa_2O_4物相,表面铜以 2价的形式存在。还原态样品的体相存在Cu~0、CuLa_2O_4,可能还有CuAlO_2,表面存在Cu~0、Ca~ 和少量的Cu~(2 )。CO容易在Cu~.、Cu_2O及CuAlO_2上形成分子态吸附;同时还存在HCO_3~-、CO_3~(2-)物种。NO容易吸附在CuO、CuAl_2O_4和CuLa_2O_4上,在Cu~0上可能解离吸附,还产生NO_3~-吸附物种。氧化态样品上,150℃以上,CO使Cu~(2 )还原为Cu~ 。还原态样品上,NO和CO交替吸附和共吸附实验证明低温出现了NO/Cu~(2 )和CO/Cu~ 的选择吸附现象。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-