Ni/SAPO-11分子筛催化剂的制备与异构化性能研究

采用水热合成法制备了SAPO—11分子筛,以SAPO—11分子筛为载体,制备了Ni/SAPO—11分子筛催化剂。研究了催化剂上正庚烷的异构化反应。详细讨论了催化剂的制备条件、还原条件及反应条件的改变对庚烷异构化反应性能的影响。结果表明,2%Ni/SAPO—11分子筛催化剂对正庚烷异构化反应具有较好的异构化性能。当镍负载量为2%,还原时间为4 h,还原温度为430℃时,催化剂的性能最好,转化率为61.67%时,异构化选择性能够达到70.67%。     

异丙苯在不同硅含量SAPO-5分子筛上的裂化反应特征

在ESR－GC－Computer联机的动态装置下，用固定床微型石英催化反应器，研究不同硅含量SAPO－5（22），SAPO－5（19），SAPO－5（5）及AlPO4－5和HY分子筛对异丙苯裂化反应的催化活性、ESR幅值特征．并测定催化剂的积炭量．结果表明，催化剂的催化活性、ESR幅值及积炭量大小之排序一致，均为HY》SAPO－5（22）＞SAPO－5（19）＞SAPO－5（5）》AlPO4－5．在SAPO－5和AlPO4－5催化剂上，异丙苯反应前后吸附吡啶的IR谱证实，异丙苯在SAPO－5催化剂上的裂化反应是在B酸中心进行的．     

SAPO-11中硅含量对长链烷烃加氢异构化反应的影响

合成了3个不同硅含量的SAPO－11分子筛,通过29Si MAS NMR,Py-IR,扫描电镜,N2吸附等方法对其进行表征,并用脉冲微反考察了载钯后在正十二烷加氢异构化反应中的催化性能,将表征结果与异构化性能关联,提出了与“孔口模型”不同的观点,指出SAPO－11中的较强B酸对加氢异构化反应起主要作用,为提高和改进Pd/SAPO-11催化剂的性能提供了科学依据。     

氟离子改性的AlPO_4-5和AlPO_4-11分子筛的研究

作者用2%的氟化铵溶液对A1PO_(4-5)和A1PO(4_11)分子筛进行了改性。产物经X射线粉末衍射、红外光谱、吸附水后的热重—失重速率等方法进行分析,结果表明氟化后分子筛的骨架发生改变.表面酸性研究表明氟化后分子筛不具B酸中心和L酸中心。     

合成高硅SAPO影响因素的研究

0引言 1984年kok等人将si引入A1P04系列分子筛中合成出一系列磷酸硅铝（SAPO）子筛,从此,SAPO分子筛的合成和应用得到迅速发展。SAPO分子筛骨架呈负电性具有可交换的阳离子同时具有质子酸性,因此被广泛用作吸附剂、催化种及催化剂载体成为第三代新型分子筛爱到催化领域科研工作者的广泛重视。由于许多反应需要较高酸性的催化剂,而提高硅含量可以在一定程度上提高分子筛的酸性,因此合成高硅SAPO分子筛越来越引起人们的广泛兴趣。本文重点对合成高硅SAPO的影响因素进行了综述。     

Ni—Y分子筛的表面酸性及对甲苯脱烷基反应催化作用

本文采用吡啶中毒脉冲色诏技术,在440～500℃范围的反应条件下,考察了 Ni—Y 分子筛的甲苯脱烷基反应表面活性中心及其催化作用.结果表明:Br(?)nsted 酸和 Lewis 酸均有催化作用.但活性规律不尽一致,它们对脱烷基反应的贡献又随温度的变化出现相反结果,在465℃以下时 B酸中心起主要作用.而在490℃以上 L 酸中心的作用占主导地位,在480℃左右二者的作用相当.催化剂再生实验指出,吡啶在 Ni—Y 上的吸附具有一定可逆性.对脉冲中毒催化剂进行红外光谱检测,发现1450.4Cm~(-1)和1536.3Cm~(-1)处有吡啶分子与 L 酸和 B 酸作用的特征吸收带,给出了L 酸和 B 酸含量之比 C_L/C_B=1.68,相对含量 C_L%=62.69%,C_B%=37.31%.     

原位漫反射红光谱考察SAPO—34分子筛骨架

原位漫反射红光谱是一新的原位表征技术，该方法用于表征磷酸硅铝分子筛SDAPO－34的骨架，结果表明：SAPO－34在高温时骨架有一定程度的“变形”，这种“变形”是可逆的，在温度降至室温时又恢复正常，并且SAPO－34有很高的湿热稳定性，同时探讨了表征中的方法问题。     

缓和加氢裂化催化剂表面酸性对催化剂活性的影响

用浸渍法制备了两个系列的含分子筛催化剂,用溶剂法和吡啶吸附红外光谱法研究了催化剂表面酸性,并在连续微反装置上以正辛烷为原料,评价了催化剂活性。在此实验基础上,探讨了催化剂表面酸性和催化剂活性之间的关系。实验结果表明,催化剂中分子筛类型和含量影响催化剂表面总酸量、强酸量、L酸量以及B酸量。催化剂表面B酸中心是催化剂加氢裂化活性中心,催化剂表面L酸中心能提高催化剂的抗氮性能,因而可提高催化剂对含氮化合物原料的加氢裂化性能。     

差热-色谱联用法测吸附热——Ⅱ、吡啶在~γ-Al_2O_3及Na×沸石上吸附热的研究

用自行设计的差热-色谱吸附量热系统测定了170℃—270℃吡啶在γ—Al_2O_3和Na×沸石上的吸附热。证实了γ—Al_2O_3表面上存在的酸中心主要是L酸中心,温度升高时,酸量减少,酸强度减弱,减弱的程度因吸附位置的不同而不同。在Na×沸石表面上,存在两种对吡啶分别呈不可逆与可逆吸附的酸中心,较强的一种是非活化的L酸中心,较弱的一种是活化的B酸中心。温度变化对这两种酸中心的影响各有不同。计算表明,β笼和八面沸石笼中的吸附中心部分地为H_2O分子所占据、     

ZSM—5分子筛上液化石油气芳构化反应的研究

采用常压连续流动微反装置，考察了液化石油气在HZSM－5分子筛及各种改性分子筛上的芳构化反应，并对抑制积炭延长分子筛活性稳定性方面做了研究。根据测得的催化剂样品上的吡啶吸附红外光谱及氨的TPD结果，提出了芳构化的活性中心是由B酸与L酸共同构成，B酸与L酸应有适宜配比的观点。     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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