高纯度异戊烷的制备方法研究

目前炼油厂生产的异戊烷产品酸值在(20~80)×10-6 mgKOH/g左右,不符合乙烯生产用制冷剂的企业标准(5×10-6 mgKOH/g以下),为增强异戊烷产品在市场上的竞争力,需将其酸值降至5×10-6 mgKOH/g以下.将未合格的异戊烷样品经浓硫酸搅拌,使样品碘值降至合格后,再通过装有碱片的分离柱使其酸值达到要求     

蓖麻油甲酯基润滑油基础油的制备及性能研究

蓖麻油甲酯(FAME)是蓖麻油与甲醇通过酯交换反应生成得到,将FAME与甲酸和过氧化氢,在催化剂硫酸作用下,发生环氧化反应生成环氧脂肪酸甲酯(EFAME).研究了H_2O_2的滴加温度,反应温度,反应时间,H_2O_2/HCOOH/FAME物质的量比,催化剂用量等环氧化反应条件.对产品的碘值,环氧值,黏度(40℃),倾点,凝点和氧化稳定性进行了测定.结果表明,相比FAME,EFAME的碘值从80.1 g/(100 g)降至2.8 g/(100 g),环氧值从0.03 mol/100g增加至1.75 mol/100g,因此,EFAME的氧化稳定性显著提高,但是低温流动性变差,黏度也增加.在下列条件:H_2O_2滴加温度50℃,反应温度50℃,反应时间10 h,n(H_2O_2)∶n(HCOOH)∶n(FAME)=5∶1∶1,催化剂用量1.5 g,环氧化反应产物的氧化稳定性较好,缓和氧化后非挥发相的酸值X_1为0.7×10~(-6) mgKOH/g,缓和氧化后挥发相的酸值X_2为0.5×10~(-8) mgKOH/g,深度氧化后沉积物含量X_3为70.2%(质量分数),深度氧化后的酸值X_4为3.3×10~(-6) mgKOH/g,相应的碘值为2.8 g/(100 g),环氧值1.75 mol/(100 g).     

灭活大肠杆菌吸附铅离子的实验研究

研究了反应条件对灭活大肠杆菌吸附铅离子的影响，实验结果表明，在起始浓度ρ(Pb^2 )为10～100mg／L范围内，吸附量为1．832～21．248mg／g(干生物体)，反应在10分钟内达到吸附平衡，最佳反应温度和pH值分别为30℃和6，离子浓度与吸附量之间的关系符合Freundlich等温吸附方程，K值为2．3281，n值为1．7668。     

采用微波加热与共沸精馏分水联合方法合成松香丁酯

利用硫酸作催化剂,在微波加热与共沸精馏分水联合的新型酯化反应装置中合成松香丁酯。最佳反应条件为：正丁醇与松香的摩尔比为6：1、催化剂用量为松香用量的6％、反应时间为120min,微波功率为607．5W。粗产品酸值为52mgKOH／g,产率为92％。     

漆酶／介体系统对尾叶桉硫酸盐浆漂白的条件探索

利用从白腐菌(Panus conchatus)产生的酶液中分离纯化出漆酶(Laccase)。在一种新的介体NHA的存在下构成L／MS系统(Laccase—Mediator System)进行尾叶桉浆生物漂白。通过对尾叶桉进行深化脱木素的改良连续蒸煮(EMCC)，结果表明，L／MS系统生物漂白的最佳条件为：漆酶用量为2．5U／g纸浆，NHA用量为1％／g纸浆，最适pH=6．0，酶处理时间为8小时，反应温度为50℃，并通氧气。     

RuCl3/TPPTS催化CO选择还原间氯硝基苯反应

将水溶性膦／钌配合物用于以CO为还原剂的水／有机两相间氯硝基苯选择还原为间氯苯胺的反应．考察了十六烷基三甲基溴化铵(CTAB)与氢氧化钠(NaOH)浓度、反应温度、CO压力以及膦／钌比例等因素对反应结果的影响．研究结果表明，当反应条件为135℃、CO压力3MPa、NaOH浓度2mol／L时，反应8h，问氯硝基苯的转化率为97％，间氨苯胺的选择性可达到99％以上．通过简单的相分离操作就能将水相中的催化剂循环使用，循环使用3次后，间氯硝基苯的转化率和间氨苯胺的收率仍可达到89％以上．     

水稻基因组DNA的RAPD扩增研究

通过对水稻RAPD反应条件比较研究，建立了对除草剂敏感致死水稻RAPD的最适反应体系和反应扩增程序，即在25止反应体系中，含10mmol／LTris-HCl(pH8．0)，10mmol／LKCI，8mmol／L(NH4)2804，0．05％NP-40，2．0mmol／LMgCl2，0．1mmol／L(each)dTNPs，20ng引物，20ng基因组DNA，1．5U的Taq酶。反应扩增程序为：94℃变性2min；扩增40个循环，每循环包括：94℃变性10s，40℃退火30s，72℃延伸1．5min；最终延伸5min。     

麦冬果实药用成分测定

采用火焰原子吸收法在同一溶液中测定了麦冬果实中8种矿质元素的含量，采用UV法对麦冬中总黄酮的含量进行了测定．分析结果表明，麦冬果实中钾、钙等微量元素含量丰富，如钾达到17．09mg／g、钙达到8．22mg／g，总黄酮高峰期可达4．412mg／mL，低峰期也达2．015mg／mL．     

正极材料LiFePO4的电化学性能的改进

采用固相反应法合成了LiFePO4正极材料，在20mA／g的电流密度下进行恒电流充放电，比容量可以达到135mAh/g，为了改进LiFePO4的性能，提高其高倍率性能，尝试了两种途径并合成出Li(Fe0．8Mn0．2)PO4和LiFePO4/C。低倍率充放电实验得出的两个样品的比容量分别可达到145mAh／g和144mAh／g，而且表现出了良好的循环性能和平坦的电压平台，以上两种方法制备出的材料均具有较好的高倍率性能。     

米糠油脂肪酸甘油脂组成及理化指标的测定

通过气相色谱-质谱分析了米糠汕的主要脂肪酸廿汕酯组成。结果表明：米糠含汕率为15．2％,其中主要含有亚汕酸甘汕脂37．08％,汕酸甘汕脂34．12％,棕榈酸甘油脂21．84％,硬脂酸甘汕脂2．89％,瓦克芩酸甘油脂1．2l％,花生酸甘油脂0．97％,豆蔻酸脂肪脂0．64％,不饱和脂肪酸脂占总油脂的72．41％。理化指标测定结果表明：米糠油相对密度(d4^20)为0．9255,折射率(20℃)为1．4720,酸价(mgKOH／g)为1．9,碘价(gl／100g)为105。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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