加氢催化剂酸性质研究

将溶剂法用于测定深色的加氢裂化和加氢处理催化剂的表面酸量及酸强度分布,并且用氨吸附-差热分析法进行了对照实验,发现两者有类似的酸强度分布曲线。用溶剂法考察了活性金属氧化物对催化剂酸性的影响,发现某些活性金属氧化物如NiO和WO_3自身没有强酸部位,却具有使无定形硅铝或含分子筛的酸性载体强酸量增加的能力。对照进行的吡啶吸附-红外光谱实验结果表明,活性金属氧化物使催化剂表面的Brosted酸量发生了与溶剂法所测得的强酸量有一定的相关关系的变化;用溶剂法测定了酸性组份(超稳Y型分子筛)含量不同的载体以及用这些载体制成的Ni-W催化剂的强酸量,发现溶剂法对试样酸性的变化反应灵敏。当载体含有45％(质量)超稳Y型分子筛时,加入Ni-W活性组份能使其强酸部位的增量达到最大。     

微孔分子筛对催化合成3-甲基-6-叔丁基苯酚的影响研究

目的对微孔分子筛催化合成3-甲基-6-叔丁基苯酚开展研究,探讨影响催化剂活性的主要因素,以期为工业化生产提供理论支撑。方法以HY,ReUSY,USY,LaY,ZMS-5,Hβ等微孔分子筛为催化剂进行性能评价,采用X射线衍射、场发射扫描电子显微镜、N_2物理吸附仪和化学吸附仪等表征方法对催化剂进行表征,并与催化剂活性数据进行关联。结果 Y型、Hβ分子筛具有较好的催化活性,其中USY催化剂具有较好的转化率,最高达到68.6%,ZSM-5具有最优选择性,最高接近100%。结论催化剂的活性主要受比表面积、孔道结构、酸密度及酸强度等的影响,比表面积及孔道结构决定原料的转化率高低,酸密度及酸强度等影响目标产物的选择性,强酸位的存在会导致深度脱烷基化的发生。     

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。     

Y型分子筛催化剂的表面酸性及其催化性能

利用吡啶吸附红外光谱（Py-IR）和X射线衍射法表征了磷钨酸（PW）、氢氧化铌改性分子筛的表面酸性和结构,用催化法脱除芳烃中微量烯烃的烷基化反应研究其酸催化性质。结果表明：催化剂的结构、表面酸含量和磷钨酸、氢氧化铌在催化剂中所占的比例,都显著地影响烷基化反应;Dawson结构的磷钨酸比Kiggen结构的磷钨酸具有较好的催化烷基化反应活性;随着磷钨酸含量的增加,催化剂B酸量先增加后减少,L酸量减少;随着氢氧化铌含量的增加,总B酸量和L酸量都减少,催化剂的活性随总B酸量与总L酸量比值的增加而提高;用磷酸或草酸处理氢氧化铌,总B酸量与总L酸量的比值增大,可进一步提高分子筛的活性和寿命。研究结果还表明：强B酸不利于脱烯烃反应。     

Au/CeNaY催化剂的制备、表征及其水汽变换反应性能

对Na Y分子筛进行Ce4+交换改性,获得Ce Na Y载体,继而负载Au制备一系列Au/Ce Na Y催化剂。采用电感耦合等离子光谱分析仪(ICP-OES)、N2物理吸附仪、X线衍射仪(XRD)、高分辨透射电子显微镜(HRTEM)和H2程序升温还原(H2-TPR)等方法对负载纳米Au催化剂进行表征,并考察催化剂的水汽变换反应活性。结果表明:随着载体中Ce4+含量增加,催化剂的Au负载量逐渐提高,比表面积和孔容显著下降,且纳米Au颗粒均匀地分散于分子筛载体上。Au/Ce Na Y比Au/Na Y具有更高的水汽变换反应活性,且Au/Ce Na Y催化剂的反应活性随载体中的Ce4+含量的增加而提高。在350℃时,Au/Na Y的反应活性为2.6 mol/(mol·h),而Au/Ce Na Y的反应活性高达33.2 mol/(mol·h)。     

用催化剂脱除芳烃中微量烯烃的研究

以分子筛为活性组分，与一定比例的载体混合后制成催化剂并评价了该类催化剂的活性和稳定性，用吡啶FT-IR测定了催化剂的表面酸性；同时探讨了催化剂表面酸性与催化剂活性之间的关系，发现催化剂的活性不仅与总酸量有关，还和B酸量与L酸量之比有关。当催化剂上B酸量与L酸量达到恰当比例时，催化剂的活性最好。     

钙铁镍钒对Y型分子筛影响概述

Y型分子筛在FCC催化剂中广泛应用,催化裂化原料油中常含有Ca、Fe、V、Ni,这些金属在反应过程中会沉积在催化剂表面,对催化剂的性能产生一定的影响。本文对Ca、Fe、V、Ni金属对Y型分子筛的结构影响进行了简述。     

分子筛型固体酸催化剂用于长直链烯烃和苯的烷基化反应

以分子筛型固体酸代替氢氟酸作催化剂,研究了长直链烯烃和苯的烷基化反应。对各种类型分子筛的研究表明:以金属阳离子交换的Y型分子筛为催化剂,在常压、苯/烯=8(摩尔比)、烯/剂=6(重量比)的条件下,反应0.5小时,烯烃的转化率可达97%以上,苯的单烷基化的选择性在90%以上。提高反应温度和压力可进一步提高烯烃的转化率,当反应温度150℃、压力2MPa、重量空速6h~(-1)时,烯烃转化率高于90%的时间可达100小时以上。     

苯酚烷基化反应的Y型分子筛催化剂研究

以Y型分子筛为固体酸催化剂,分别从催化剂的改性、制备因素和反应参数,对文题进行了研究。结果表明:在引入相同金属阳离子后。随着Na~+交换度的提高,总酸量减小,催化活性降低;当焙烧温度为550℃时,催化剂的总酸量、比表面积和催化活性均为最高;在常压、175℃、气体空速2000h~(-1)、叔丁醇/苯酚=1.2∶1(mol)条件下,苯酚转化率为69%,对叔丁基苯酚选择性达85%。     

磷对烃类催化裂化催化剂表面酸性及抗炭性能的影响

考察了磷改性对催化裂化（ＦＣＣ）催化剂的表面酸性、抗炭性及反应活性的影响，探讨了催化剂表面酸性与抗炭性能的关系，结果表明，在以超稳Ｙ分子筛作为活性组分的ＦＣＣ催化剂中引入磷元素，能降低催化剂的表面酸强度，减少酸中心数，降低催化剂的积炭速率，同时加入适量的磷有利于提高催化剂的反应活性。     

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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