三苄基锡羧酸酯的合成及催化性能研究

合成了3种苄基锡羧酸酯,并对其进行了表征及催化性能评价。三苄基锡羧酸酯对醇醛缩合反应有很好的催化选择性,对醇酸酯化反应有很高的催化活性和选择性,副反应很小。     

SO2-4/TiO2-SnO2/ZSM-5催化合成乙酸丁酯

以乙酸和正丁醇的酯化为探针反应，考察了ＳＯ２－４／ＴｉＯ２－ＳｎＯ２／ＺＳＭ－５催化剂的催化性能．实验结果表明：ＺＳＭ－５分子筛上负载钛锡双组元氧化物，比起负载单组元ＴｉＯ２，在相同的负载液浓度下，催化活性提高了１４％，且焙烧温度和Ｔｉ∶Ｓｎ（原子比）对催化活性亦有较大的影响．在回流温度下，催化剂投入量为乙酸加入量的３．２ｗｔ％，反应２ｈ，酯化率达９６．４％．     

SO4^2—／TiO2／SnO2／ZSM—5催化合成乙酸丁酯

以乙酸和正丁醇的酯化为探针反应,考察了ＳＯ４＾２－ＴｉＯ２－ＳｎＯ２／ＺＳＭ－５催化剂的催化性能。实验结果表明：ＺＳＭ－５分子筛上负载钛锡双组元氧化物,比起负载单组元ＴｉＯ２,在相同的负载液浓度下,催化活性提高了１４％,且焙烧温度和Ｔｉ：Ｓｎ（原子比）对催化活性亦有较大的影响。在回流温度下,催化剂投入量为乙酸加入量的３．２ｗｔ％,反应２ｈ,酯化率达９６．４％。     

新的5,3‘,5’—三羟基7—甲氧基黄酮及其一二和三苄氧基衍…

通过３．５－二苄氧苯甲酸‘－２，６－二羟基－４－甲氧基苯丙酮酯进行Ｂａｋｅｒ－Ｖｅｎｋａｔａｒａｍａｎ重排，环化合成了５，３’，５’－三苄氧基－７－甲氧基黄酮，然后选择性才全部地脱苄基得到５，３’，５’－三羟基－７－甲氧基黄酮及其一和二－苄基衍生物。     

新的5，3＇，5＇－三羟基7－甲氧基黄酮及其一，二和三苄氧基衍生物的合成

通过３．５－二苄氧苯甲酸－２，６－二羟基－４－甲氧基苯丙酮酯进行Ｂａｋｅｒ－Ｖｅｎｋａｔａｒａ－ｍａｎ重排，环化合成了５，３＇，，５，三苄氧基７－甲氧基黄酮，然后选择性地和全部地脱节基得到５，３＇，５＇－三羟基－７－甲氧基黄酮及其一和二苄基衍生物．     

三种非质子酸催化剂的催化性能考察

用考察考察了氧化亚锡、钛酸四丁酯和六水合三氯化铁等3种非质子酸催化剂在石油酸酯化反应中的催化性能。结果表明，在180－230℃下，石油酸与一元醇的摩尔比为0．5，氧化亚锡或钛酸四丁酯用量占石油酸用量的1％－2％，反应3－4h4后都可使石油酸的酯化反应率达99％。在石油酸与二元醇的摩尔比为2．2时，氧化亚锡用量占石油酸用量的2％，反应4h可使二元醇烃基的酯化率达99％。氧化亚锡可重复使用，且酸液的后处理工艺简单。在120－140℃下，石油酸与一元醇的摩尔比为0．33－0．40，六水合三氯化铁的用量占石油酸用量的21％，反应4h可使石油酸的酯化率达到98％。     

三（环氧丙基）异氰尿酸酯的合成研究

本文采用异氰尿酸与环氧氯丙烷在Ｎ－十二烷基－Ｎ，Ｎ－二甲基－苄基溴化铵催化下，制取三（环氧丙基）异氰尿酸酯。     

稀土固体超强酸催化合成对羟基苯甲酸酯

制备了一系列稀土固体超强酸用于催化对羟基苯甲酸酯。研究了稀土固体超强酸的催化性能，同时研究了反应的条件，结果表明，这些催化剂基本上都有较高的催化活性，且性能稳定，具有重复使用性。     

钴络合物催化双羰化氯苄合成苯丙酮酸

α－酮酸是合成α－氨基酸和α－羟基酸的中间体．在Ｃｏ２（ＣＯ）８或Ｃｏ２（ＣＯ）８－Ｃｏ（ＰＰｈ３）ｍＸｎ催化下,苄基卤经双羰化合成苯丙酮酸,并初步研究了其反应机理．     

一种C2对称二亚砜手性辅助试剂的应用：σ—对称十员氧杂环 …

顺－２－丁烯－１,４－二醇的１,４－二羟基被邻二苯甲基保护形成环烯２、然后氧化生成α－对称十员氧杂环－１,２－二醇３,将３转化为单三甲基硅醚４后,在三氟甲磺酸三甲基硅酯（ＴＭＳＯＴｆ）的催化下,与Ｃ２－对称二亚砜手性辅助试剂１进行缩酮化反应得到光学活性缩酮５。随后的碱催化缩酮开裂反应非对映选择性大于９９％。最后,水解去掉手性辅助试剂,以良好的产率和９５％ｅｅ的光学纯度得到光学活性醇７。     

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