LPG/柴油混合燃料喷雾液滴尺寸分布的数值模拟

运用最大熵原理和质量守恒定律,推导出混合燃料喷雾液滴尺寸分布函数,建立了柴油和LPG/柴油混合燃料的喷雾液滴尺寸分布模型,对纯柴油、LPG与柴油质量掺混比为30%的L30混合燃料进行了模拟计算,并与试验结果进行了对比分析.结果表明:由于LPG的闪急沸腾效应,LPG/柴油混合燃料的喷雾液滴尺寸分布相对于柴油的尺寸分布向小颗粒方向偏移;计算数据与试验数据拟合很好,柴油中溶入LPG有助于改善雾化质量.     

正丁醇/柴油PAHs简化机理的构建与仿真

为了探讨正丁醇/柴油碳烟的生成途径,分析了正丁醇氧化历程和PAHs(苯、萘、菲、芘)生成路径,保留了与正丁醇/柴油混合燃料PAHs生成密切相关的基元反应,对正丁醇的氧化机理和PAHs的生成机理进行了简化,并加入正庚烷简化机理,构建了由73种组分和89个基元反应的正丁醇/柴油PAHs简化机理.采用简化机理对正丁醇/柴油混合燃料的反应温度等参数进行模拟,结果与反射激波管试验结果一致,验证了简化机理的可行性.在此基础上通过模拟计算,分析了正丁醇/柴油不同掺混比、当量比的PAHs生成量和生成速率随时间变化的规律.结果表明:随着正丁醇掺混比的增加,PAHs生成量和生成速率逐渐减小,峰值出现时刻推迟,总生成量的降幅依次增大;随着当量比的增大,PAHs物质的量峰值增大,峰值出现的时刻推迟.     

十六烷值改进剂对柴油/甲醇混合燃料燃烧特性的影响

采用常规商业柴油、分析级无水甲醇和助溶剂配制了均匀混合的柴油／甲醇燃料，在TY1100单缸、水冷、直喷柴油机上对添加了十六烷值改进剂后的柴油/甲醇混合燃料的燃烧特性进行了试验研究，试验表明：与柴油相比，柴油／甲醇混合燃料燃烧的滞燃期延长，缸内最大气体压力增加；加入十六烷值改进剂后，柴油／甲醇混合燃料的滞燃期明显缩短，大负荷时的缸内最大气体压力减小。     

生物柴油的氧化安定性

为了考察生物柴油的氧化安定性,通过8 h加速氧化试验,定时取样,分析了氧化油的运动粘度、酸值和过氧化值,并与不同掺混比的生物柴油/柴油混合燃料进行比较.结果表明:生物柴油的氧化安定性比柴油差,两者混合燃料的氧化安定性随生物柴油掺混比的增大而逐渐变差.考察了4种抗氧化剂对生物柴油氧化安定性的影响,通过筛选确定了一种效果良好的抗氧化剂,对生物柴油的氧化具有明显的抑制作用.     

模糊控制调制柴油/甲醇发动机瞬态工况的甲醇喷射量

针对车用发动机瞬态工况多的特点,应用模糊控制策略,对采用柴油/甲醇组合燃烧发动机在瞬态工况下的甲醇控制量实施控制.依据此控制策略,开发了一套柴油/甲醇电控系统.该系统的甲醇喷射量由台架试验标定得到控制脉谱数据,将其应用于一台只达到国Ⅱ排放标准的增压中冷发动机上进行国Ⅲ标准的ELR试验,能使柴油/甲醇发动机满足国Ⅲ标准的ELR试验烟度要求.在一辆装配了柴油/甲醇组合燃烧发动机的城市中巴车上进行了道路试验,结果表明,模糊控制策略能有效增大甲醇替代柴油比例,显著改善组合燃烧发动机在瞬态工况烟度排放,而且能提高燃料的经济性和加速响应.     

O2/CO2环境对柴油燃烧特性的影响

为计算柴油在O2/CO2环境中火焰浮起长度（FLOL）,提出了柴油的耦合计算模型。该模型基于空气卷吸率计算公式,考虑了O2和CO2对FLOL的影响,引入空气与燃料的动态化学当量比,得到了O2/CO2环境中FLOL的计算公式。运用Converge软件对柴油的表征燃料正庚烷建立化学模型和物理模型,搭建了定容燃烧弹可视化试验台。对柴油在空气、50%O2/50%CO2和57%O2/43%CO2环境中的FLOL进行计算与试验,并对燃烧过程、温度云图和FLOL进行了分析。结果表明：该模型能计算柴油在O2/CO2环境中的FLOL,计算的最大平均误差为8.6%。     

柴油乳化工艺条件的试验研究

叙述了使用ＨＱ－Ｉ型柴油乳化剂进行柴油乳化工艺条件的优选试验,得到了最佳乳化工艺条件,并介绍了应用试验结果。     

脂肪酸甲酯对生物柴油氧化性能和热值的影响

采用FTIR分析了菜籽油、大豆油、小桐子油及其甲酯化之后的生物柴油在特征峰处的异同点,GCMS分析了生物柴油中主要脂肪酸甲酯含量.在3种生物柴油中分别添加了不同含量的油酸甲酯、硬脂酸甲酯,分别测定了添加前后其氧化诱导期变化以及热值变化,并使用Gaussian09计算了油酸甲酯、硬脂酸甲酯的碳氢键解离能.试验结果表明:硬脂酸甲酯对生物柴油氧化诱导期影响比油酸甲酯更加明显,模拟结果与试验结果一致;生物柴油中添加脂肪酸甲酯之后热值会随着单组分脂肪酸甲酯的增加而增加,逐渐接近于单组分脂肪酸甲酯的热值大小.     

直馏柴油催化氧化脱硫工艺中试研究(Ⅰ)

针对柴油加氢脱硫技术设备投资和操作费用高,柴油H₂O₂氧化脱硫技术又存在氧化剂价格高、柴油收率低和有含硫污水排放等技术经济问题,开发了一种新型直馏柴油催化氧化脱硫方法,在此为其中试试验研究。直馏柴油催化氧化脱硫中试装置由催化氧化反应、催化剂再生回收、萃取脱硫与萃取剂回收等四个单元组成;反应器为静态混合反应器;在建立的中试装置上对直馏柴油催化氧化脱硫操作条件进行了优选实验：在表观停留时间3～5min、反应温度60℃、反应物料循环量1000L/h、氧化催化剂/柴油体积比为0.24和柴油/萃取剂体积比为2.5的最佳实验操作条件下,成品柴油的硫含量从2273μg/g降到106μg/g,柴油硫含量符合欧洲Ⅱ类柴油标准(≤300μg/g),脱硫率达到95.34%,柴油收率为97.23%。     

直馏柴油催化氧化脱硫工艺中试研究(II)

采用直馏柴油催化氧化脱硫工艺中试装置,在表观停留时间3～5min、反应温度60℃、氧化催化剂/柴油体积比0.24,反应物料循环量1000L/h和柴油/萃取剂体积比2.5的试验条件下对直馏柴油进行催化氧化脱硫中试研究。精制柴油的产品分析表明：柴油中的主要硫化物二苯并噻吩类被氧化为极性的砜类化合物经萃取脱出,本工艺脱硫效果良好。富集硫化物柴油与催化柴油按1∶10的体积比混合,在模拟兰州石化炼油厂柴油加氢工业装置的操作条件下加氢脱硫,可使混合富硫柴油中的硫含量从2500μg/g降低到800μg/g。富集硫化物柴油可作为催化裂化柴油加氢装置的原料。     

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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