愈创木酚和乙醛酸缩合反应的影响因素

以愈创木酚和乙醛酸为原料-,通过缩合反应试验合成3-甲氧基-4-羟基-苯乙醇酸(MHMA)。研究了原料的配比、原料的加入方式、反应温度、反应时间、反应体系碱浓度等因素对愈创木酚和乙醛酸缩合反应的影响。乙醛酸转化率可达84.0%,MHMA收率可达80%以上。     

4-羟基-3-甲氧基苯乙胺盐酸盐的合成

以香草醛和硝基甲烷为原料,通过缩合、还原和成盐反应,合成了4-羟基-3-甲氧基苯乙胺盐酸盐,并通过IR和1HNMR对其结构进行了表征。进一步探讨了反应温度、催化剂用量和反应物摩尔比对缩合反应产率的影响,以及还原剂的制备、反应温度和反应时间对还原反应产率的影响,还原产率达到66.8%。     

3,4-二取代基-β-苯乙胺盐酸盐类化合物的合成

3,4-二取代基-β-苯乙胺盐酸盐类化合物是四氢异喹啉类化合物合成过程中的一个重要中间体。以3,4-二羟基苯甲醛为原料,经溴代物取代,硝基甲烷缩合,NaBH4/BF3还原3步反应合成了该类目标化合物。考察了缩合反应及还原反应中各原料投料比、反应时间、反应温度对反应收率的影响。优化后平均反应总收率可达67.6%,且反应条件温和、避免了以往该类化合物合成过程中氰化钠等剧毒性物质的使用,产品经ESI-MS和1HNMR确证结构。     

脂肪酸高级烷醇酰胺的研制

以脂肪酸为原料经酯化、缩合制取高级烷醇酰胺。用正交实验设计考察了反应温度、反应时问、催化剂种类及其用量、原料配比等对酯化、缩合反应的影响,得出了优化反应条件。     

诺氟沙星合成工艺的改进

本文以3-氯-4-氟苯胺为起始原料,经与乙氧甲叉丙三酸二乙酯(EMME)缩合、Gould～Jacobs环化、乙基化、硼酸酯络合及与无水哌嗪缩合等五步反应合成了诺氟沙星,总收率为66．3％。     

阿哌沙班中间体的合成

阿哌沙班是一种新型口服抗凝血药物。以对硝基苯胺和5-氯戊酰氯为原料,依次经过酰化-环合、二氯化、缩合-消除、[3+2]环合-消除反应合成阿哌沙班的关键中间体。该方法4步反应总收率为58.1%,反应所需原料易得,反应条件温和,反应步骤短,产品纯度高达99.5%(HPLC法),为阿哌沙班的合成提供了原料。     

异噁唑酰腙类化合物的合成及其结构表征

以5-甲基4-异噁唑甲酸为原料,与氯化亚砜、水合肼反应得5一甲基4-异噁唑甲酰肼2,2与芳香醛缩合反应合成了6个新的酰腙化合物,其结构经IR、1HNMR、MS等表征确证.实验结果表明,酰肼与芳香醛在冰醋酸中进行缩合酰腙化反应,具有产率高、条件温和、操作简便等优点.     

2,2-二羟甲基丁酸的合成工艺研究

本文以丁醛和甲醛为原料,经缩合及氧化二步反应,合成2,2-二羟甲基丁酸。并确定了反应的最佳工艺条件。     

头孢拉宗的合成

以D-苏氨酸为起始原料合成头孢拉宗.D-苏氨酸为起始原料,经甲硅烷化后与4-乙基-2,3-二氧-1-哌嗪甲酰氯缩合制得侧链酸,再与7-TMCA缩合、C7位引入甲氧基得到头孢拉宗.目标化合物经核磁共振氢谱确证其化学结构.该合成方法工艺简单,反应效率提高.     

左西替利嗪的合成

以4-氯二苯甲酮为原料,经Leuckart反应、酸解、拆分、环合、酸解、缩合、缩合及成盐酸盐7步反应合成左西替利嗪,总收率为5.0%.对合成化合物5的去酸剂进行了考察,选用价廉的三正丙胺代替文献中二异丙基乙胺,所得产物收率接近文献收率.     

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