α-蒎烯高选择性环氧化合成2,3-环氧蒎烷的研究

笔者以α-蒎烯为原料高选择性环氧化合成2,3-环氧蒎烷。探讨了过氧乙酸浓度及用量、碳酸钠用量、溶剂类型、反应温度及反应时间等对α-蒎烯转化率、2,3-环氧蒎烷选择性及产物组成的影响;确定了适宜的环氧化反应条件:反应温度为0～10℃;过氧乙酸浓度2.0 mol/L,α-蒎烯与过氧乙酸物质量之比为1∶1.1;α-蒎烯与碳酸钠物质量之比为1∶1.2;反应时间2 h;以氯仿为溶剂,溶剂用量为α-蒎烯与氯仿体积比1∶1.7。在此条件下α-蒎烯转化率为99%以上,2,3-环氧蒎烷的选择性大于95%,反应产物中主要杂质α-龙脑烯醛和3-蒎酮的含量仅为3.3%和1.2%左右。     

Li_2CuCl_4催化α,ω-二溴代烷与格氏试剂的单端不对称偶联反应研究

本文报道了格氏试剂与α.ω——二溴代烷在Li_2CuCl_4催化下的不对称偶联反应。指出了二溴代烷碳链长度和反应温度对单偶联产物收率的影响,并对Li_2CuCl_4在此反应中的催化机理作了初步探讨。     

固体超强酸SO2-4/ZrO2催化α-蒎烯异构反应

研究了固体超强酸SO2-4/ZrO2催化剂的制备条件(硫酸浸渍浓度、焙烧温度等)对其催化性能的影响.结果表明,催化剂的制备条件不同,对莰烯选择性和α-蒎烯转化率有较大影响.适宜的催化剂制备条件是: 硫酸浓度0.5～1.0 mol/L,焙烧温度650 ℃.对所制备的SO2-4/ZrO2固体超强酸作为α-蒎烯异构反应的催化剂,以及对影响反应过程的主要因素进行探讨.优化的工艺条件为:反应时间1～3 h,反应温度(130±2)℃,催化剂质量分数3%～4%.该条件下α-蒎烯转化率96.4%,莰烯选择性49.7%.此外,还分析了催化剂放置时间对异构产物的影响及催化剂重复使用情况.     

固体超强酸SO4^2-／ZrO2催化α-蒎烯异构反应

研究了固体超强酸SO2-4/ZrO2催化剂的制备条件(硫酸浸渍浓度、焙烧温度等)对其催化性能的影响.结果表明,催化剂的制备条件不同,对莰烯选择性和α-蒎烯转化率有较大影响.适宜的催化剂制备条件是 硫酸浓度0.5～1.0 mol/L,焙烧温度650 ℃.对所制备的SO2-4/ZrO2固体超强酸作为α-蒎烯异构反应的催化剂,以及对影响反应过程的主要因素进行探讨.优化的工艺条件为反应时间1～3 h,反应温度(130±2)℃,催化剂质量分数3%～4%.该条件下α-蒎烯转化率96.4%,莰烯选择性49.7%.此外,还分析了催化剂放置时间对异构产物的影响及催化剂重复使用情况.     

M-ZSM-5催化α-蒎烯空气环氧化反应

采用不同的金属离子交换Na-ZSM-5型分子筛制备M-ZSM-5催化剂.以空气作为氧化剂,N,N-二甲基甲酰胺(DMF)作为溶剂,用M-ZSM-5催化环氧化α-蒎烯.采用XRD和IR对催化剂进行表征,结果表明ZSM-5经过离子交换后其基本骨架结构没有发生变化.结果表明Co-ZSM-5的催化活性最高,以1.2%Co-ZSM-5型分子筛为催化剂,空气作为氧化剂并用少量的TBHP作为引发剂,采用DMF作为溶剂,在90℃下反应5 h,α-蒎烯的转化率达84.5%,α-蒎烯环氧化物选择性达78.1%.催化剂经过回收利用,发现催化效果基本保持一致.     

纳米固体超强酸S2O82-/ZrO2催化的β-蒎烯异构化反应

主要研究了纳米固体超强酸S2O8^2-/ZrO2催化的β-蒎烯异构化反应,实验结果表明,该催化剂具有很高的催化活性和选择性.异构化反应的主产物是莰烯,副产物主要是苧烯、蒈烯、三环烯、α-松油烯和对异丙基甲苯等.异构化反应的最佳条件是：反应温度70℃,反应时间4 h,催化剂用量为β-蒎烯质量的3%.在此最佳条件下,β-蒎烯转化率为100%,莰烯选择性为61.90%.     

负载杂多酸催化剂催化合成直链烷基苯的研究

在固定床反应器和一定的反应条件下，考察了改变苯烯摩尔比对负载杂多酸催化剂催化合成直链烷基苯的活性和选择性的影响。实验结果表明，随着苯烯比的增加，十二烯的转化率和2位-十二烷基苯的选择性均有所增加。在苯烯摩尔比4∶1、液体质量总空速10h^-1、温度120℃和液固反应条件下，对催化剂的稳定性进行了实验考察，结果显示，连续反应70h后，负载杂多酸催化剂的活性明显下降。利用SEM、FT-IR和TG等对失活催化剂进行了基本表征，结果表明积炭可能是引起负载杂多酸催化剂失活的主要原因。     

ω——溴代烯丙式醇化合物合成研究

本文报导了合成ω-溴代烯丙式醇的方法。以11-溴-十一酸为原料,通过α—溴代,选择性去溴化氢,然后在适当条件下直接用LiAlH_4还原,得到11—澳一十一烯—2—醇—1。中间产物及最终产物均采用柱层析分离得到纯品,并经IR.~1HNMR和MS测定证明其结构。     

树脂负载型催化剂催化环十二碳三烯环氧化的反应研究

以过氧化氢(H_2O_2)为氧化剂,以阴离子交换树脂为载体负载的过氧磷钨酸为催化剂,催化环十二碳三烯选择环氧化生成单环氧化物.采用XRD和SEM等手段对催化剂进行了表征.研究结果表明,以阴离子树脂载体负载的磷钨杂多酸为催化剂在催化环十二碳三烯选择环氧化反应中展现出较好的催化活性.在以过氧化氢为氧化剂,阴离子树脂D261负载过氧磷钨酸为催化剂时,60℃反应4 h,环十二碳三烯的转化率为72.6%,单环氧化物的选择性为74.6%.     

溴化四苯基膦催化碳酸乙烯酯水解合成乙二醇反应

通过对碳酸乙烯酯催化水解合成乙二醇反应机理的研究,找到了一种适合本法较好的催化剂-溴化四苯基膦,然后考察了催化剂的量、水比、反应温度、反应压力、反应时间等因素对反应转化率和选择性的影响,确定了本法较佳的反应工艺条件为:水比2.0-3.0,反应温度140-150℃,反应压力3.0-4.0MPa,催化剂用量2%左右,反应时间2-2.5h,在此条件下反应的转化率和选择性都能达到98%以上,并对各因素的影响运用STATISTICA 6.0进行了统计分析,得出水比和催化剂的量是影响转化率的主要因素,而选择性主要由水比和反应温度所决定.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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