大豆油酯交换制备生物柴油的研究

利用K2CO3和Al2O3制备固体碱催化剂,将它用于大豆油和甲醇酯交换制备生物柴油.通过实验考察醇油摩尔比,催化剂用量,反应温度和反应时间4个工艺条件对生物柴油产率的影响,最后确定最佳的反应条件为:醇油摩尔比9:1,催化剂用量2%,温度60℃,反应时间4h,在此条件下得到的生物柴油产率为72.3%.     

KOH/Al2O3固体碱催化酯交换合成生物柴油的研究

采用等体积浸渍法制备了KOH/Al_2O_3负载型固体碱催化剂,并将其用于菜籽油与甲醇酯交换法合成生物柴油的研究;分别考察了催化剂附载量、煅烧温度、醇油摩尔比、反应温度、反应时间等条件对生物柴油产率的影响;结果表明:用等体积浸渍法,在400℃煅烧5 h,制得负载量为20%(w)的KOH/Al_2O_3催化剂.当催化剂用量为5%(w),醇油摩尔比为12:1,在60℃下反应2 h后,生物柴油产率高达92.3%(w).运用X-射线衍射、比表面积测定等手段对催化剂结构进行了表征,结果表明催化剂的活性与其晶相和比表面积密切相关.     

KOH/Al_2O_3固体碱催化酯交换合成生物柴油的研究

采用等体积浸渍法制备了KOH/Al_2O_3负载型固体碱催化剂,并将其用于菜籽油与甲醇酯交换法合成生物柴油的研究;分别考察了催化剂附载量、煅烧温度、醇油摩尔比、反应温度、反应时间等条件对生物柴油产率的影响;结果表明:用等体积浸渍法,在400℃煅烧5 h,制得负载量为20%(w)的KOH/Al_2O_3催化剂.当催化剂用量为5%(w),醇油摩尔比为12:1,在60℃下反应2 h后,生物柴油产率高达92.3%(w).运用X-射线衍射、比表面积测定等手段对催化剂结构进行了表征,结果表明催化剂的活性与其晶相和比表面积密切相关.     

膨润土负载型固体酸催化剂催化合成生物柴油

以自制固体酸催化剂ZnCl2/膨润土催化大豆油制备生物柴油,考察了反应条件对生物柴油产率的影响.结果表明:在ZnCl2负载量30%、催化剂用量5%、醇油物质的量比10∶1、反应温度65℃和反应时间5h时,生物柴油的产率可以达到82%以上.自制生物柴油的性能指标完全达到0#普通柴油标准和柴油机燃料调和用生物柴油标准要求.     

碱催化猪油制备生物柴油的研究

以猪油为原料,选用KOH为碱性催化剂制备生物柴油。经单因素实验及正交实验研究了油醇比、反应温度、反应时间和催化剂用量对生物柴油产率的影响。结果表明:在实验条件下各因素对生物柴油产率影响的大小依次为:油醇体积比>催化剂用量>反应温度>反应时间。最佳反应条件为:油醇体积比4∶1,反应温度60℃,KOH用量为1.1%(油重),反应时间为45 min,产率为91.94%,脂肪酸甲酯含量为96.3%,精制后总甘油含量0.23%。     

固体酸催化大豆油甲酯化制备生物柴油的研究

以甲醇和大豆油为原料,以固体酸为催化剂,通过酯交换反应制备生物柴油.考察了反应时间、反应温度、催化剂用量和醇油摩尔比各单因素对生物柴油产率的影响,得到最佳工艺条件:反应时间3.5 h,反应温度70℃,催化剂用量为大豆油质量的6.0%,醇油摩尔比为7:1,生物柴油产率可达93.5%.     

基于均匀设计的生物柴油最优制备工艺参数研究

以均匀设计法安排试验,对大豆油在酯交换反应下制备生物柴油的工艺进行了研究.为获得最优制备工艺参数,考查了n(醇)∶n(油)(3∶1～8∶1)、催化剂质量分数(0.4%～1.4%)、反应温度为(45～70℃)、反应时间(40～140min)及其交互作用对生物柴油产率和原料转化率的影响.结果表明:n(醇)∶n(油)、催化剂用量可显著地影响生物柴油的产率和原料转化率.同时甲醇与反应温度、催化剂与反应时间之间存在对抗效应,而甲醇与反应时间、催化剂与反应温度、反应温度与反应时间之间则存在协同作用.利用回归分析和BP神经网络,确定最优工艺参数为:n(醇)∶n(油)=6∶1;催化剂质量分数1.0%;反应温度45℃;反应时间30min.经液相色谱仪测定,生物柴油产率高达97.6%.     

活性炭负载固体碱催化制备生物柴油研究

大豆油在以活性炭为载体的负载型固体碱催化剂(KOH/C,K2CO3/C,KNO3/C)的作用下与甲醇酯交换反应制备生物柴油.考察了催化剂用量、醇油摩尔比、反应温度、时间等因素对产物收率的影响.结果表明:以上3种催化剂都可以催化酯交换反应,其中KOH\C的催化效果最好.当催化剂的质量为大豆油的2％、醇油摩尔比为10:1、...     

负载型固体碱催化制备生物柴油的研究

以负载型固体碱(KF/Al2O3、KNO3/Al2O3和K2CO3/Al2O3)作催化剂,菜籽油与甲醇通过酯交换反应制备生物柴油,系统地研究了催化剂制备条件及酯交换条件对产物收率的影响.结果表明:以上3种催化剂都可以较好地催化酯交换反应,其中负载KF催化剂的催化效果更好一些.当催化剂焙烧温度为873 K、负载物和载体的质量比为0.15~0.20时制备的催化剂活性最强,用此催化剂催化酯交换反应,当醇油摩尔比为12∶1~10∶1、催化剂用量为2%~3%、时间为60 min、温度为333~338 K时,生物柴油收率可达85%~87%.     

大豆油酯交换法制备生物柴油

采用大豆油在催化剂氢氧化钠作用下与甲醇发生酯交换反应制备生物柴油.研究了醇油摩尔比、催化荆质量分数、反应时间、反应温度等对反应产率的影响.采用红外光谱表征产品.实验结果表明,当醇油摩尔比5.9:1,反应时间2 h,催化荆用量为原料油质量的0.99%,反应温度65℃时,生物柴油的收率最高,为87%.     

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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