变换-甲烷化催化剂上氢和水的吸附及其与CO的反应性能

本文应用脉冲色谱法,对镍基催化剂上H_2和H_2O的不可逆吸附,以及CO和它们的反应情况进行了研究。观察到水的解离吸附特点及其对变换-甲烷化反应,尤其是对CO活化吸附的影响。证明了实际镍基催化剂上甲烷化反应的表面碳机理。并对变换-甲烷化反应机理进行了探讨。     

甲烷氧化偶联催化剂和部分氧化反应机理的原位及非原位谱学表征

采用原痊红外和原位显微Raman光谱技术及XPS、吡啶（Py)吸附的漫反射UV谱、Py-TPD、CO2-TPD等方法对含氟稀土基催化剂上甲烷氧化偶联（OCM）反应活性氧物种、催化剂表面酸碱性进行了考察。在O2预处理和/或工作条件下的SrF2/La2O3,SrF2/Nd2O3,LaOF,BaF2/LaOF和BaF2/CeO2等催化剂上原位观测到超氧物种（O2^-),并在其中前4种催化剂上检测到O2^-物种与CH4反应生成的气相C2H4,CO2和表面碳酸盐等OCM反应主、副产物。这些结果为O2^-是相应催化剂上OCM反应的活性氧物种首次提供了直接的光谱证据。研究结果表明,催化剂的OCM反应性能与其表面酸碱性的强弱并无简单的对应关系。采用原拉时间分辨红外光谱和原位显微Raman光谱技术对SiO2和γ-Al2O3负载的Rh、Ru催化剂上甲烷部分氧化（POM）制合成气反应的研究表明,由CH4直接氧化生成CO和H2是Rh/SiO2上POM反应的主要途径,而燃烧-重整机理是Ru/γ-Al2O3和Ru/SiO2上CO和H2生成的主要途径,反应条件下催化剂表面氧（O^2-)物种浓度的差异很可能是导致这两种催化剂体系上POM反应机理不同的主要原因,其本质可能源于Rh和Ru对氧的亲合力的不同。     

镍基上甲烷与二氧化碳脱氢重整机理的理论研究

采用密度泛函理论(DFT)及二级微扰(MP2)方法对使用镍基催化剂上甲烷的逐步脱氢后与CO2发生重整反应制合成气的机理进行了研究.计算结果表明,甲烷进行4步脱氢后生成镍基碳,同时释放出氢气,镍基碳再与CO2反应生成CO.反应分5步进行,其焓变分别为-104.310,52.501,55.135,315.602,-202.164 kJ/mol.5步反应的活化能表明第1步和第5步反应较易进行,反应的速控步骤是第4步,其正反应的活化能为577.610 kJ/mol.     

流化床上甲烷催化转化制合成气Ni/SiO2催化剂性能研究

考察了流化床上Ni／SiO2催化剂对甲烷部分氧化和甲烷二氧化碳重整耦合反应的催化性能．研究了Ni负载量，反应温度、预还原温度对催化性能的影响．结果表明，镍基催化剂具有很高的初活性，但是在线反应6h后催化剂很快失活．TG、XRD和TEM分析结果显示高温下镍晶粒的聚集长大是催化剂活性显著下降的主要原因．     

甲烷催化部分氧化制合成气反应机理

甲烷催化部分氧化制合成气在负载型金属催化剂上的反应机理目前仍然存在争议。一种观点认为 ,甲烷先与氧气燃烧生成水和二氧化碳 ,在燃烧过程中氧气完全消耗 ,剩余的甲烷再与水和二氧化碳进行重整反应生成氢气和一氧化碳 ,即燃烧重整机理 ;另一种观点认为 ,甲烷直接在催化剂上分解生成氢气和表面碳物种 ,表面碳再与表面氧反应生成一氧化碳 ,即直接氧化机理。对复合氧化物催化剂上的反应机理 ,一致认为甲烷与氧气在催化剂表面上先形成氧化物 ,氧化物再分解生成氢气和一氧化碳。对有关甲烷催化部分氧化制合成气反应机理的不同观点进行了介绍 ,并结合作者在Ni/Al2 O3 催化剂方面的研究结果 ,对负载型镍催化剂上的反应机理进行了讨论     

甲烷催化部分氧化制合成气反应机理

甲烷催化部分氧化制合成气在负载型金属催化上的反应机理目前仍然存在争议。一种观点认为,甲烷先与氧气燃烧生成水和二氧化碳,在燃烧过程中氧气完全消耗,剩余的甲 烷再与水和二氧化碳进行重整反应生成氢气和一氧化碳,即燃烧－重整机理;另一种观点认为,甲烷直接在催化剂上分解生成氢气和表面碳物种、表面碳再与表面氧反应生成一氧化碳,即直接氧化机理。对复合氧化物催化剂上的反应机理,一致认为甲烷与氧气在催化剂表面上先形成氧化物,氧化物再分解生成氢气和一氧化碳。对有关甲烷催化部分氧化制合成气反应机理的不同观点进行了介绍,并结合作者在Ni/Al2O3催化剂方面的研究结果,对负载型镍催化剂上的反应机理进行了讨论。     

F-T合成铁-锰系催化剂的TPSR方法表征

采用程序升温表面反应(TPSR)方法,研究了F-T合成铁-锰系催化剂于不同条件下吸附CO后,在催化剂表面形成的不同加氢活性碳物种的形态和反应性。结果表明,一氧化碳在铁基催化剂上解离后,可形成三类不同加氢活性的碳物种:表面碳(或其衍生的表面碳物种)、体相碳化物和非活性碳。其中,表面碳是形成甲烷及高级烃的表面活性中间物;体相碳化物可能是催化剂在反应条件下的真实活性相;而非活性碳则可能导致催化剂的失活。适量的锰、钾助剂对一氧化碳的解离及碳物种的形成起促进作用。     

在Fe_2O_3－K_2O催化剂上乙苯程序升温脱附研究──探讨乙苯脱氢反应机理

乙苯在Ｆｅ＿２Ｏ＿３－Ｋ＿２Ｏ催化剂上的ＴＰＤ研究表明，新鲜催化剂表面有α和β两种活性位，均具脱氢、脱乙基和裂解活性．乙苯吸附后能脱氢生成苯乙烯和脱乙基生成苯，若预先吸附水亦可脱甲基生成甲苯，新鲜催化剂表面氧化能力较强，脱下的的氢或烷基会立即与表面晶格氧作用生成Ｈ＿２Ｏ和ＣＯ＿２，并致使催化剂表面被还原产生新的γ活性位．γ位裂解性能较强，但在吸附水后也具有脱氢和脱烷基活性，水对甲苯的生成起着重要的作用，α活性位可能是Ｋ＿２Ｆｅ＿２Ｏ＿４相，β和γ位可能是Ｆｅ＿２Ｏ＿３和Ｆｅ＿３Ｏ＿４（部分还原的氧化铁）相．     

V2 O5/γ-Al2O3催化剂的乙苯混合脱氢研究

采用等体积浸渍法制备了一系列V2O5/γAl2O3催化剂,用程序升温还原反应(TPR)、X射线光电予能谱分析(XPS)、粉末X射线衍射分析(XRD)和N2物理吸附对催化剂进行了表征,并考察了催化剂在CO2气氛下乙苯氧化脱氢反应性能和在系统中通入O2对催化剂结构和催化性能的影响.结果表明,随着V负载量的增加,催化剂在CO2氧化乙苯脱氢过程中的初活性增加,但催化剂的稳定性变差;在CO2氧化乙苯过程中加入少量O2可以有效抑制催化剂表面积碳,同时使催化剂表面高价态的V物种含量增加,从而维持较高的活性和稳定性.     

费托催化剂η-Fe_2C(011)上CO吸附与活化行为

低温Fe基费托催化剂的主要活性相是_η-Fe_2C,CO在该催化剂上的吸附与活化行为是Fe基费托合成反应的重要步骤。为了从原子尺度上研究这一过程,本文基于密度泛函理论计算,在η-Fe_2C(011)完美表面和缺陷表面上对CO的吸附和活化行为进行了系统的对比研究。计算结果表明,CO在完美表面上的最稳定吸附位为与表面Fe结合的Top位,但活化前驱体位于三齿空位。CO直接解离路径因为能垒太高在_η-Fe_2C(011)完美表面上很难发生,而以HCO为中间体的H辅助CO解离路径则更有优势。当_η-Fe_2C(011)表面产生C空缺时,其生成的四齿空位成为CO的最稳定吸附位和活性位。同时,CO的直接解离能垒大幅下降,这导致CO直接解离和以HCO为中间体的H辅助解离路径可能同时发生。     

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.     

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.     

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.     

A computer generator for randomly layered structures

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

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

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.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to